U.S. patent application number 10/793567 was filed with the patent office on 2007-12-13 for transportation fuels.
Invention is credited to John C. Eckstrom, William H. Gong, Michael Hodges, George A. JR. Huff, Monica Cristina Regalbuto, Douglas N. Rundell, Leslie R. Wolf.
Application Number | 20070283617 10/793567 |
Document ID | / |
Family ID | 25115919 |
Filed Date | 2007-12-13 |
United States Patent
Application |
20070283617 |
Kind Code |
A1 |
Huff; George A. JR. ; et
al. |
December 13, 2007 |
TRANSPORTATION FUELS
Abstract
The present invention relates to Compositions of fuels for
transportation are disclosed, particularly organic compositions
which are liquid at ambient conditions. More specifically, it
relates to transportation fuels comprising suitable organic
distillates, as a predominant component, and limited, but
essential, amounts of a component comprising oxygen-containing
organic materials, which materials are typically derived from
natural petroleum. Beneficially, the oxygen content of these
transportation fuels is at least 0.02 percent by weight. Preferably
the oxygen content these transportation fuels is in a range from
about 0.2 percent to about 10 percent by weight.
Inventors: |
Huff; George A. JR.;
(Naperville, IL) ; Gong; William H.; (Elmhurst,
IL) ; Wolf; Leslie R.; (Naperville, IL) ;
Eckstrom; John C.; (Elburn, IL) ; Rundell; Douglas
N.; (Glen Ellyn, IL) ; Hodges; Michael;
(Wonersh, GB) ; Regalbuto; Monica Cristina;
(Glenview, IL) |
Correspondence
Address: |
BP America Inc.;Docket Clerk
BP Legal, M.C. 5East
4101 Winfield Road
Warrenville
IL
60555
US
|
Family ID: |
25115919 |
Appl. No.: |
10/793567 |
Filed: |
March 4, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09779288 |
Feb 8, 2001 |
6872231 |
|
|
10793567 |
Mar 4, 2004 |
|
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Current U.S.
Class: |
44/300 |
Current CPC
Class: |
C10G 27/04 20130101;
C10L 1/02 20130101; C10L 1/026 20130101; C10G 27/10 20130101 |
Class at
Publication: |
044/300 |
International
Class: |
C10L 1/10 20060101
C10L001/10 |
Claims
1.-14. (canceled)
15. A composition for fuel or blending component of fuels which are
liquid at ambient conditions, the composition formed by a process
which comprises: partitioning by distillation an organic feedstock
comprising a mixture of organic compounds derived from natural
petroleum, the mixture having a gravity raging from about
10.degree. API to about 75.degree. API to provide a first organic
part consisting of a sulfur-lean, mono-aromatic-rich fraction, and
a second organic part consisting of a sulfur-rich,
mono-aromatic-lean fraction; contacting a gaseous source of
dioxygen with at least a portion of the first organic part in a
liquid reaction medium containing a soluble catalyst system
comprising a source of at least one catalyst metal selected from
the group consisting of compounds represented by formula
M[RCOCH.dbd.C(O--)R'].sub.n where M is one or more member of the
group consisting of manganese, cobalt, nickel, chromium, vanadium,
molybdenum, tungsten, tin and cerium, R and R' are the same or
different members selected from the group consisting of a hydrogen
atom and alkyl, aryl, alkenyl and alkynyl groups having up to about
20 carbon atoms, and n is 2 or 3, while maintaining the liquid
reaction medium substantially free of halogen and/or
halogen-containing compounds, to form a mixture of immiscible phase
comprising hydrocarbons, oxygenated organic compounds, water of
reaction, and acidic co-products; separating from the mixture of
immiscible phases at least a first organic liquid comprising
hydrocarbons, oxygenated organic compounds and acidic co-products
and second liquid which contains at least portions of the catalyst
metal, water of reaction and acidic co-products; and contacting all
or a portion of the separated organic liquid with a neutralizing
agent thereby recovering an oxygenated product.
16. The composition according to claim 15 wherein at least a
portion of the separated organic liquid is contacted with an
aqueous solution of a chemical base, and the recovered oxygenated
product exhibits a total acid number of less than about 20 mg
KOH/g.
17. The composition according to claim 16 wherein the chemical base
is a compound selected from the group consisting of sodium,
potassium, barium, calcium and magnesium in the form of hydroxide,
carbonate or bicarbonate.
18. The composition according to claim 15 wherein all or at least a
portion of the organic feedstock is a product of a hydrotreating
process for petroleum distillates consisting essentially of
material boiling between about 50.degree. C. and about 425.degree.
C. which hydrotreating process includes reacting the petroleum
distillate with a source of hydrogen at hydrogenation conditions in
the presence of a hydrogenation catalyst to assist by hydrogenation
removal of sulfur and/or nitrogen from the hydrotreated petroleum
distillate.
19.-20. (canceled)
21. The composition according to claim 15 wherein the catalyst
system comprises a source of catalyst metal selected from the group
consisting of compounds represented by formula
Mn[RCOCH.dbd.C(O--)R']2, CO[RCOCH.dbd.C(O--)R']2 and/or
Ce[RCOCH.dbd.C(O--)R']3 where R and R' are the same or different
members selected from the group consisting of a hydrogen atom and
alkyl, aryl, alkenyl and alkynyl groups having up to about 20
carbon atoms.
22. The composition according to claim 15 further comprising an
effective amount of one or more fuel additives which enhance
desired fuel properties.
23.-26. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to compositions of fuels for
transportation, particularly organic compositions which are liquid
at ambient conditions. More specifically, it relates to
transportation fuels comprising suitable organic distillates, as a
predominant component, and limited, but essential, amounts of a
component comprising oxygen-containing organic materials, which
materials are typically derived from natural petroleum.
Beneficially, the oxygen content of these transportation fuels is
at least 0.02 percent by weight.
BACKGROUND OF THE INVENTION
[0002] It is well known that internal combustion engines have
revolutionized transportation following their invention during the
last decades of the 19th century. While others, including Benz and
Gottleib Wilhelm Daimler, invented and developed engines using
electric ignition of fuel such as gasoline, Rudolf C. K Diesel
invented and built the engine named for him which employs
compression for auto-ignition of the fuel in order to utilize
low-cost organic fuels. Development of improved diesel engines for
use in transportation has proceeded hand-in-hand with improvements
in diesel fuel compositions. Modern high performance diesel engines
demand ever more advanced specification of fuel compositions, but
cost remains an important consideration.
[0003] At the present time most fuels for transportation are
derived from natural petroleum. Indeed, petroleum as yet is the
world's main source of hydrocarbons used as fuel and petrochemical
feedstock. While compositions of natural petroleum or crude oils
are significantly varied, all crudes contain sulfur compounds and
most contain nitrogen compounds which may also contain oxygen, but
the oxygen content of most crudes is low. Generally, sulfur
concentration in crude is less than about 8 percent, with most
crudes having sulfur concentrations in the range from about 0.5 to
about 1.5 percent. Nitrogen concentration is usually less than 0.2
percent, but it may be as high as 1.6 percent.
[0004] Crude oil seldom is used in the form produced at the well,
but is converted in oil refineries into a wide range of fuels and
petrochemical feedstocks. Typically fuels for transportation are
produced by processing and blending of distilled fractions from the
crude to meet the particular end use specifications. Because most
of the crudes available today in large quantity are high is sulfur,
the distilled fractions must be desulfurized to yield products
which meet performance specifications and/or environmental
standards. Sulfur containing organic compounds in fuels continue to
be a major source of environmental pollution. During combustion
they are converted to sulfur oxides which, in turn, give rise to
sulfur oxyacids and, also, contribute to particulate emissions.
[0005] Even in newer, high performance diesel engines combustion of
conventional fuel produces smoke in the exhaust. Oxygenated
compounds and compounds containing few or no carbon-to-carbon
chemical bonds, such as methanol and dimethyl ether, are known to
reduce smoke and engine exhaust emissions. However, most such
compounds have high vapor pressure and/or are nearly insoluble in
diesel fuel, and they have poor ignition quality, as indicated by
their cetane numbers. Furthermore, other methods of improving
diesel fuels by chemical hydrogenation to reduce their sulfur and
aromatics contents, also causes a reduction in fuel lubricity.
Diesel fuels of low lubricity may cause excessive wear of fuel
injectors and other moving parts which come in contact with the
fuel under high pressures.
[0006] Distilled fractions used for fuel or a blending component of
fuel for use in compression ignition internal combustion engines
(Diesel engines) are middle distillates that usually contain from
about 1 to 3 percent by weight sulfur. In the past a typical
specifications for Diesel fuel was a maximum of 0.5 percent by
weight. By 1993 legislation in Europe and United States limited
sulfur in Diesel fuel to 0.3 weight percent. By 1996 in Europe and
United States, and 1997 in Japan, maximum sulfur in Diesel fuel was
reduced to no more than 0.05 weight percent. This world-wide trend
must be expected to continue to even lower levels for sulfur.
[0007] In one aspect, pending introduction of new emission
regulations in California and Federal markets has prompted
significant interest in catalytic exhaust treatment. Challenges of
applying catalytic emission control for the diesel engine,
particularly the heavy-duty diesel engine, are significantly
different from the spark ignition internal combustion engine
(gasoline engine) due to two factors. First, the conventional TWC
catalyst is ineffective in removing NOx emissions from diesel
engines, and second, the need for particulate control is
significantly higher than with the gasoline engine.
[0008] Several exhaust treatment technologies are emerging for
control of Diesel engine emissions, and in all sectors the level of
sulfur in the fuel affects efficiency of the technology. Sulfur is
a catalyst poison that reduces catalytic activity. Furthermore, in
the context of catalytic control of Diesel emissions, high fuel
sulfur also creates a secondary problem of particulate emission,
due to catalytic oxidation of sulfur and reaction with water to
form a sulfuric acid mist. This mist is collected as a portion of
particulate emissions.
[0009] Compression ignition engine emissions differ from those of
spark ignition engines due to the different method employed to
initiate combustion. Compression ignition requires combustion of
fuel droplets in a very lean air/fuel mixture. The combustion
process leaves tiny particles of carbon behind and leads to
significantly higher particulate emissions than are present in
gasoline engines. Due to the lean operation the CO and gaseous
hydrocarbon emissions are significantly lower than the gasoline
engine. However, significant quantities of unburned hydrocarbon are
adsorbed on the carbon particulate. These hydrocarbons are referred
to as SOF(soluble organic fraction). Thus, the root cause of health
concerns over diesel emissions can be traced to the inhalation of
these very small carbon particles containing toxic hydrocarbons
deep into the lungs.
[0010] While an increase in combustion temperature can reduce
particulate, this leads to an increase in NOx emission by the
well-known Zeldovitch mechanism. Thus, it becomes necessary to
trade off particulate and NOx emissions to meet emissions
legislation.
[0011] Available evidence strongly suggests that ultra-low sulfur
fuel is a significant technology enabler for catalytic treatment of
diesel exhaust to control emissions. Fuel sulfur levels of below 15
ppm, likely, are required to achieve particulate levels below 0.01
g/bhp-hr. Such levels would be very compatible with catalyst
combinations for exhaust treatment now emerging, which have shown
capability to achieve NOx emissions around 0.5 g/bhp-hr.
Furthermore, NOx trap systems are extremely sensitive to fuel
sulfur and available evidence suggests that they need would sulfur
levels below 10 ppm to remain active.
[0012] In the face of ever-tightening sulfur specifications in
transportation fuels, sulfur removal from petroleum feedstocks and
products will become increasingly important in years to come. While
legislation on sulfur in diesel fuel in Europe, Japan and the U.S.
has recently lowered the specification to 0.05 percent by weight
(max.), indications are that future specifications may go far below
the current 0.05 percent by weight level.
[0013] Conventional hydrodesulfurization (HDS) catalysts can be
used to remove a major portion of the sulfur from petroleum
distillates for the blending of refinery transportation fuels, but
they are not active for removing sulfur from compounds where the
sulfur atom is sterically hindered as in multi-ring aromatic sulfur
compounds. This is especially true where the sulfur heteroatom is
doubly hindered (e.g., 4,6-dimethyldibenzothiophene). Using
conventional hydrodesulfurization catalysts at high temperatures
would cause yield loss, faster catalyst coking, and product quality
deterioration (e.g., color). Using high pressure requires a large
capital outlay.
[0014] In order to meet stricter specifications in the future, such
hindered sulfur compounds will also have to be removed from
distillate feedstocks and products. There is a pressing need for
economical removal of sulfur from distillates and other hydrocarbon
products.
[0015] The art is replete with processes said to remove sulfur from
distillate feedstocks and products. One known method involves the
oxidation of petroleum fractions containing at least a major amount
of material boiling above a very high-boiling hydrocarbon materials
(petroleum fractrions containing at least a major amount of
material boiling above about 550.degree. F.) followed by treating
the effluent containing the oxidized compounds at elevated
temperatures to form hydrogen sulfide (500.degree. F. to
1350.degree. F.) and/or hydroprocessing to reduce the sulfur
content of the hydrocarbon material. See, for example, U.S. Pat.
No. 3,847,798 in the name of Jin Sun Yoo and U.S. Pat. No.
5,288,390 in the name of Vincent A. Durante. Such methods have
proven to be of only limited utility since only a rather low degree
of desulfurization is achieved. In addition, substantial loss of
valuable products may result due to cracking and/or coke formation
during the practice of these methods. Therefore, it would be
advantageous to develop a process which gives an increased degree
of desulfuriztion while decreasing cracking or coke formation.
[0016] Several different oxygenation methods for improving fuels
have been described in the past. For example, U.S. Pat. No.
2,521,698 describes a partial oxidation of hydrocarbon fuels as
improving cetane number. This patent suggests that the fuel should
have a relatively low aromatic ring content and a high paraffinic
content. U.S. Pat. No. 2,912,313 states that an increase in cetane
number is obtained by adding both a peroxide and a dihalo compound
to middle distillate fuels. U.S. Pat. No. 2,472,152 describes a
method for improving the cetane number of middle distillate
fractions by the oxidation of saturated cyclic hydrocarbon or
naphthenic hydrocarbons in such fractions to form naphthenic
peroxides. This patent suggests that the oxidation may be
accelerated in the presence of an oil-soluble metal salt as an
initiator, but is preferably carried out in the presence of an
inorganic base. However, the naphthenic peroxides formed are
deleterious gum initiators. Consequently, gum inhibitors such as
phenols, cresols and cresyic acids must be added to the oxidized
material to reduce or prevent gum formation. These latter compounds
are toxic and carcinogenic.
[0017] U.S. Pat. No. 4,494,961 in the name of Chaya Venkat and
Dennnis E. Walsh relates to improving the cetane number of raw,
untreated, highly aromatic, middle distillate fractions having a
low hydrogen content by contacting the fraction at a temperature of
from 50.degree. C. to 350.degree. C. and under mild oxidizing
conditions in the presence of a catalyst which is either (i) an
alkaline earth metal permanganate, (ii) an oxide of a metal of
Groups IB, IIB, IIIB, IVB, VB, VIB, VIIB or VIIIB of the periodic
table, or a mixture of (i) and (ii). European Patent Application 0
252 606 A2 also relates to improving cetane number of a middle
distillate fuel fraction which may be hydro-refined by contacting
the fraction with oxygen or oxidant, in the presence of catalytic
metals such as tin, antimony, lead, bismuth and transition metals
of Groups IB, IIB, VB, VIB, VIIB and VIIIB of the periodic table,
preferably as an oil-soluble metal salt. The application states
that the catalyst selectively oxidizes benzylic carbon atoms in the
fuel to ketones.
[0018] Recently, U.S. Pat. No. 4,723,963 in the name of William F.
Taylor suggests that cetane number is improved by including at
least 3 weight percent oxygenated aromatic compounds in middle
distillate hydrocarbon fuel boiling in the range of 160.degree. C.
to 400.degree. C. This patent states that the oxygenated
alkylaromatics and/or oxygenated hydroaromatics are preferably
oxygenated at the benzylic carbon proton.
[0019] More recently, oxidative desulfurization of middle
distillates by reaction with aqueous hydrogen peroxide catalyzed by
phosphotungstic acid and tri-n-octylmethylammonium chloride as
phase transfer reagent followed by silica adsorption of oxidized
sulfur compounds has been described by Collins et al. (Journal of
Molecular Catalysis (A): Chemical 117 (1997) 397-403). Collins et
al. described the oxidative desulfurization of a winter grade
diesel oil which had not undergone hydrotreating. While Collins et
al. suggest that the sulfur species resistant to
hydrodesulfurization should be susceptible to oxidative
desulfurization, the concentrations of such resistant sulfur
components in hydrodesulfurized diesel may already be relatively
low compared with the diesel oils treated by Collins et al.
[0020] U.S. Pat. No. 5,814,109 in the name of Bruce R. Cook, Paul
J. Berlowitz and Robert J. Wittenbrink relates to producing Diesel
fuel additive, especially via a Fischer-Tropsch hydrocarbon
synthesis process, preferably a non-shifting process. In producing
the additive, an essentially sulfur free product of these
Fischer-Tropsch processes is separated into a high-boiling fraction
and a low-boiling fraction, e.g., a fraction boiling below
700.degree. F. The high-boiling of the Fischer-Tropsch reaction
product is hydroisomerizied at conditions said to be sufficient to
convert the high-boiling fraction to a mixture of paraffins and
isoparaffins boiling below 700.degree. F. This mixture is blended
with the low-boiling of the Fischer-Tropsch reaction product to
recover the diesel additive said to be useful for improving the
cetane number or lubricity, or both the cetane number and
lubricity, of a mid-distillate, Diesel fuel.
[0021] U.S. Pat. No. 6,087,544 in the name of Robert J.
Wittenbrink, Darryl P. Klein, Michele S Touvelle, Michel Daage and
Paul J. Berlowitz relates to processing a distillate feedstream to
produce distillate fuels having a level of sulfur below the
distillate feedstream. Such fuels are produced by fractionating a
distillate feedstream into a light fraction, which contains only
from about 50 to 100 ppm of sulfur, and a heavy fraction. The light
fraction is hydrotreated to remove substantially all of the sulfur
therein. The desulfurized light fraction, is then blended with one
half of the heavy fraction to product a low sulfur distillate fuel,
for example 85 percent by weight of desulfurized light fraction and
15 percent by weight of untreated heavy fraction reduced the level
of sulfur from 663 ppm to 310 ppm. However, to obtain this low
sulfur level only about 85 percent of the distillate feedstream is
recovered as a low sulfur distillate fuel product
[0022] There is, therefore, a present need for compositions of
fuels for transportation, particularly organic compositions which
are liquid at ambient conditions, particularly compositions, which
do not have the above disadvantages.
[0023] This invention is directed to overcoming the problems set
forth above in order to provide components for refinery blending of
transportation fuels friendly to the environment.
SUMMARY OF THE INVENTION
[0024] Economical compositions are provided for transportation
fuels or blending components for transportation fuels, particularly
organic compositions which are liquid at ambient conditions. More
specifically, compositions comprising suitable organic distillates,
as a predominant component, and limited, but essential, amounts of
a component comprising oxygen-containing organic materials, which
materials are typically derived from natural petroleum.
Beneficially, the oxygen content of these transportation fuels is
at least 0.02 percent by weight. Preferably the oxygen content
these transportation fuels is in a range from about 0.2 percent to
about 10 percent by weight.
[0025] One aspect of the invention is a composition for fuel or
blending component of fuels which composition comprises: as a
predominant component organic distillates, which predominant
component exhibits a suitable initial boiling point and contains
less than 15 ppm sulfur; and one or more oxygen-containing organic
compounds in amounts such that the oxygen content of the fuel is in
a range from about 0.2 percent to about 20 percent oxygen.
[0026] Beneficially, in composition according to invention the
amounts of the oxygen-containing organic compounds are such that
[10.degree. C.+(IBP).sub.composition]>(IBP).sub.distillates,
where (IBP).sub.composition is the initial boiling point of the
composition and (IBP).sub.distillates is the initial boiling point
of the distillates.
[0027] In one class of compositions the predominant component is a
mixture of organic compounds derived from natural petroleum. In
another class of compositions the predominant-component comprises
alkanes containing from 5 to about 15 carbon atoms of which at
least about 85 percent are normal alkanes. Advantageously
composition according to the invention further comprising an
effective amount of one or more fuel additives which enhance
desired fuel properties.
[0028] This invention contemplates the use of fuel additives which
are components known to enhance desired fuel properties. Typically,
fuel additives are useful at low levels, i.e., less than 5 percent
based upon the total weight of fuel, and often an effective amount
is in a range upward from 0.01 percent and can even be as low as
0.05 percent for some cetane improvers. Useful fuel additives
include cetane improvers, dehaziers/demulsifiers, anti-oxidants,
metal deactivators, corrosion inhibitors, anti-foam agents,
lubricity improvers, dispersents, detergents, and cold flow
improvers such as pour depressants and cloud point depressants. A
preferred class of cold flow improvers are selected from the group
consisting of copolymers of ethylene and vinyl acetate, which
enhances cold flow properties.
[0029] One aspect of the invention is a fuel for use in compression
ignition internal combustion engines, comprising: as a predominant
component organic distillates, and one or more oxygen-containing
organic compounds in amounts such that the oxygen content of the
fuel is in a range from about 0.2 percent to about 10 percent
oxygen, and wherein the fuel exhibits a suitable flash point of at
least 38.degree. C. as measure by ASTM D93, and contains less than
15 ppm sulfur. Advantageously, the fuel exhibits a suitable flash
point of at least 49.degree. C. Advantageously, compositions of the
invention further comprising an effective amount of one or more
Diesel fuel additives selected from the group consisting of
copolymers of ethylene and vinyl acetate, which enhances cold flow
properties of Diesel fuel.
[0030] Another aspect of the invention is a fuel for use in spark
ignition internal combustion engines, comprising: as a predominant
component organic distillates, and one or more oxygen-containing
organic compounds in amounts such that the oxygen content of the
fuel is in a range from about 0.2 percent to about 10 percent
oxygen, and wherein the fuel exhibits a suitable Reid vapor
pressure of at least 6 psi and contains less than 15 ppm
sulfur.
[0031] One aspect of the invention is a composition for fuel or
blending component for fuels which are liquid at ambient
conditions, which composition comprises: as a predominant component
organic distillates which contain less than 15 ppm sulfur, and
oxygen-containing organic compounds derived from natural petroleum
in amounts such that the oxygen content of the fuel is in a range
from about 0.2 percent to about 10 percent oxygen, with the proviso
that at least 10 percent of the oxygen is contained in cyclic
benzylic ketones. Beneficially, composition according to invention
at least 5 percent of the oxygen content of the fuel is contained
in cyclic benzylic diketones. Beneficially, compositions of the
invention further comprising an effective amount of one or more
fuel additives which enhance desired fuel properties.
[0032] A preferred composition for fuel or blending component for
fuels, which are liquid at ambient conditions comprises: as a
predominant component petroleum distillates which contain less than
15 ppm sulfur, and oxygen-containing organic compounds derived from
natural petroleum in amounts such that the oxygen content of the
fuel is in a range from about 0.2 percent to about 10 percent
oxygen, with the proviso that at least 10 percent of the oxygen is
contained in aryl oxygenates represented by ##STR1## where R.sub.1
are independently selected from the group consisting of hydrogen
and hydrocarbon radicals containing from 1 to about 10 carbon
atoms, x is an integer from 1 to 4; R.sub.2 are independently
selected from the group consisting of hydrogen, hydroxyl, carbonyl
oxygen and organic moieties containing from 1 to about 10 carbon
atoms, and y is an integer from 1 to 3.
[0033] A preferred class of compositions comprises aryl oxygenates
of the types represented by the following: ##STR2##
[0034] In a preferred composition at least 10 percent of the oxygen
is contained in aryl oxygenates represented by ##STR3## where R1 is
hydrogen or a hydrocarbon radical containing from 1 to about 10
carbon atoms.
[0035] One aspect of this invention provides a composition formed
by an integrate process which comprises: partitioning by
distillation an organic feedstock comprising a mixture of organic
compounds derived from natural petroleum, the mixture having a
gravity ranging from about 10.degree. API to about 75.degree. API
to provide at least one low-boiling organic part consisting of a
sulfur-lean, mono-aromatic-rich fraction, and a high-boiling
organic part consisting of a sulfur-rich, mono-aromatic-lean
fraction; contacting a gaseous source of dioxygen with at least a
portion of the low-boiling organic part in a liquid reaction medium
containing a soluble catalyst system comprising a source of at
least one catalyst metal selected from the group consisting of
manganese, cobalt, nickel, chromium, vanadium, molybdenum,
tungsten, tin, cerium, or mixture thereof, while maintaining the
liquid reaction medium substantially free of halogen and/or
halogen-containing compounds, to form a mixture of immiscible
phases comprising hydrocarbons, oxygenated organic compounds, water
of reaction, and acidic co-products; separating from the mixture of
immiscible phases at least a first organic liquid of low density
comprising hydrocarbons, oxygenated organic compounds and acidic
co-products and second liquid of high density which contains at
least portions of the catalyst metal, water of reaction and acidic
co-products; and contacting all or a portion of the separated
organic liquid with a neutralizing agent and recovering a
low-boiling oxygenated product having a low content of acidic
co-products. The integrated process includes contacting the
high-boiling organic part with an immiscible phase comprising at
least one organic peracid or precursors of organic peracid in a
liquid oxidation reaction mixture maintained substantially free of
catalytic active metals and/or active metal-containing compounds
and under conditions suitable for oxidation of one or more of the
sulfur-containing and/or nitrogen-containing organic compounds;
separating at least a portion of the immiscible peracid-containing
phase from the oxidized phase of the reaction mixture; and
contacting the oxidized phase of the reaction mixture with a solid
sorbent, an ion exchange resin, and/or a suitable immiscible liquid
containing a solvent or a soluble basic chemical compound, to
obtain a high-boiling product containing less sulfur and/or less
nitrogen than the high-boiling fraction.
[0036] The catalyst system for selective oxygenation of organic
compounds according to the invention comprises a source of catalyst
metal selected from the group consisting of manganese, cobalt,
nickel, chromium, vanadium, molybdenum, tungsten, tin, cerium, or
mixture thereof, in the form of a salt of an organic acid having up
to about 8 carbon atoms
[0037] Preferably, the catalyst system for selective oxygenation of
organic compounds according to the invention comprises a source of
catalyst metal selected from the group consisting of compounds
represented by formula M[RCOCH.dbd.C(O--)R'].sub.n where n is 2 or
3. The M is one or more member of the group consisting of
manganese, cobalt, nickel, chromium, vanadium, molybdenum,
tungsten, tin and cerium, and more preferably the group consisting
of manganese, cobalt, or cerium. The R and R' are the same or
different members of the group consisting of a hydrogen atom and
methyl, alkyl, aryl, alkenyl and alkynyl groups having up to about
20 carbon atoms, and more preferably up to about 10 carbon
atoms.
[0038] Advantageously, the catalyst system for selective
oxygenation of organic compounds according to the invention
comprises a source of catalyst metal selected from the group
consisting of compounds represented by formula
Mn[RCOCH.dbd.C(O--)R'].sub.2, Co[RCOCH.dbd.C(O--)R'].sub.2 and/or
Ce[RCOCH.dbd.C(O--)R'].sub.3 where R and R' are the same or
different members of the group consisting of a hydrogen atom and
methyl, alkyl, aryl, alkenyl and alkynyl groups having up to about
20 carbon atoms, and more preferably up to about 8 carbon atoms.
Most preferred, are a source of catalyst metal selected from the
group consisting of compounds represented by formula
Mn[CH.sub.3COCH.dbd.C(O--)CH.sub.3].sub.2
Co[CH.sub.3COCH.dbd.C(O--)CH.sub.3].sub.2
Ce[CH.sub.3COCH.dbd.C(O--)CH.sub.3].sub.3
[0039] Beneficially, at least a portion of the separated organic
liquid is contacted with an aqueous solution of a chemical base,
and the recovered oxygenated product exhibits a total acid number
of less than about 20 mg KOH/g. The recovered oxygenated product
advantageously exhibits a total acid number of less than about 10
mg KOH/g. More preferred are oxygenated products which exhibit a
total acid number of less than about 5, and most preferred less
than about 1. Preferably, the chemical base is a compound selected
from the group consisting of sodium, potassium, barium, calcium and
magnesium in the form of hydroxide, carbonate or bicarbonate.
[0040] In one preferred aspect of the invention, all or at least a
potion of the organic feedstock is a product of a process for
hydrogenation of a petroleum distillate consisting essentially of
material boiling between about 50.degree. C. and about 425.degree.
C. which hydrogenation process includes reacting the petroleum
distillate with a source of hydrogen at hydrogenation conditions in
the presence of a hydrogenation catalyst to assist by hydrogenation
removal of sulfur and/or nitrogen from the hydrotreated petroleum
distillate.
[0041] Generally for use in this invention, the immiscible phase is
formed by admixing a source of hydrogen peroxide and/or
alkylhydroperoxide, an aliphatic monocarboxylic acid of 2 to about
6 carbon atoms, and water. Advantageously, the immiscible phase is
formed by admixing hydrogen peroxide, acetic acid, and water.
Advantageously, at least a portion of the separated
peracid-containing phase is recycled to the reaction mixture.
[0042] Preferably, the conditions of oxidation include temperatures
in a range upward from about 25.degree. C. to about 250.degree. C.
and sufficient pressure to maintain the reaction mixture
substantially in a liquid phase.
[0043] Sulfur-containing organic compounds in the oxidation
feedstock include compounds in which a sulfur atom is sterically
hindered, as for example in multi-ring aromatic sulfur compounds.
Typically, the sulfur-containing organic compounds include at least
sulfides, heteroaromatic sulfides, and/or compounds selected from
the group consisting of substituted benzothiophenes and
dibenzothiophenes.
[0044] Beneficially, the instant oxidation process is very
selective in that selected organic peracids in a liquid phase
reaction mixture maintained substantially free of catalytic active
metals and/or active metal-containing compounds, preferentially
oxidize compounds in which a sulfur atom is sterically hindered
rather than aromatic hydrocarbons.
[0045] Preferably, for making composition of the present invention,
suitable distillate fractions are hydrodesulfureized before being
selectively oxidized, and more preferably using a facility capable
of providing effluents of at least one low-boiling fraction and one
high-boiling fraction.
[0046] For a more complete understanding of the present invention,
reference should now be made to the embodiments illustrated in
greater detail and described below by way of examples of the
invention.
GENERAL DESCRIPTION
[0047] Advantageously, catalyst systems of the invention comprising
a source of catalyst metal selected from the group consisting of
manganese, cobalt, nickel, chromium, vanadium, molybdenum,
tungsten, tin cerium, or mixture thereof in elemental, combined, or
ionic form. The catalyst metal is preferably selected from the
group consisting of manganese and cobalt or mixture thereof, and
the metal may be employed
[0048] Preferably the source of catalyst metal is a compound having
formula M[CH.sub.3COCH.dbd.C(O--)CH.sub.3].sub.x where M is the
catalyst metal, and x is 2 or 3. When the reaction medium is a
mixture of hydrocarbons, having a gravity ranging from about
10.degree. API to about 100.degree. API, the preferred sources of
catalyst metals are Co[CH.sub.3COCH.dbd.C(O--)CH.sub.3].sub.2,
Mn[CH.sub.3COCH.dbd.C(O--)CH.sub.3].sub.2 and
Ce[CH.sub.3COCH.dbd.C(O--)CH.sub.3].sub.2 or a combination thereof.
When the reaction medium is the low-boiling fraction having the
minor amount of sulfur-containing organic compounds, the more
preferred source of catalyst metal is
Co[CH.sub.3COCH.dbd.C(O--)CH.sub.3].sub.2.
[0049] Suitable feedstocks generally comprise most refinery streams
consisting substantially of hydrocarbon compounds which are liquid
at ambient conditions. Suitable oxidation feedstock generally has
an API gravity ranging from about 10.degree. API to about
100.degree. API, preferably from about 10.degree. API to about
80.degree. API, and more preferably from about 15.degree. API to
about 75.degree. API for best results. These streams include, but
are not limited to, fluid catalytic process naphtha, fluid or
delayed process naphtha, light virgin naphtha, hydrocracker
naphtha, hydrotreating process naphthas, alkylate, isomerate,
catalytic reformate, and aromatic derivatives of these streams such
benzene, toluene, xylene, and combinations thereof. Catalytic
reformate and catalytic cracking process naphthas can often be
split into narrower boiling range streams such as light and heavy
catalytic naphthas and light and heavy catalytic reformate, which
can be specifically customized for use as a feedstock in accordance
with the present invention. The preferred streams are light virgin
naphtha, catalytic cracking naphthas including light and heavy
catalytic cracking unit naphtha, catalytic reformate including
light and heavy catalytic reformate and derivatives of such
refinery hydrocarbon streams.
[0050] Suitable oxidation feedstocks generally include refinery
distillate steams boiling at a temperature range from about
50.degree. C. to about 425.degree. C., preferably 150.degree. C. to
about 400.degree. C., and more preferably between about 175.degree.
C. and about 375.degree. C. at atmospheric pressure for best
results. These streams include, but are not limited to, virgin
light middle distillate, virgin heavy middle distillate, fluid
catalytic cracking process light catalytic cycle oil, coker still
distillate, hydrocracker distillate, and the collective and
individually hydrotreated embodiments of these streams. The
preferred streams are the collective and individually hydrotreated
embodiments of fluid catalytic cracking process light catalytic
cycle oil, coker still distillate, and hydrocracker distillate.
[0051] It is also anticipated that one or more of the above
distillate steams can be combined for use as oxidation feedstock.
In many cases performance of the refinery transportation fuel or
blending components for refinery transportation fuel obtained from
the various alternative feedstocks may be comparable. In these
cases, logistics such as the volume availability of a stream,
location of the nearest connection and short term economics may be
determinative as to what stream is utilized.
[0052] Typically, sulfur compounds in petroleum fractions are
relatively non-polar, heteroaromatic sulfides such as substituted
benzothiophenes and dibenzothiophenes. At first blush it might
appear that heteroaromatic sulfur compounds could be selectively
extracted based on some characteristic attributed only these
heteroaromatics. Even though the sulfur atom in these compounds has
two, non-bonding pairs of electrons which would classify them as a
Lewis base, this characteristic is still not sufficient for them to
be extracted by a Lewis acid. In other words, selectively
extraction of heteroaromatic sulfur compounds to achieve lower
levels of sulfur requires greater difference in polarity between
the sulfides and the hydrocarbons.
[0053] By means of liquid phase oxidation according to this
invention it is possible to selectively convert these sulfides
into, more polar, Lewis basic, oxygenated sulfur compounds such as
sulfoxides and sulfones. Compounds such as dimethylsulfide are very
non-polar molecules. Accordingly, by selectively oxidizing
heteroaromatic sulfides such as benzo- and dibenzothiophene found
in a refinery streams, processes of the invention are able to
selectively bring about a higher polarity characteristic to these
heteroaromatic compounds. Where the polarity of these unwanted
sulfur compounds is increased by means of liquid phase oxidation
according to this invention, they can be selectively extracted by a
polar solvent and/or a Lewis acid sorbent while the bulk of the
hydrocarbon stream is unaffected.
[0054] Other compounds which also have non-bonding pairs of
electrons include amines. Heteroaromatic amines are also found in
the same stream that the above sulfides are found. Amines are more
basic than sulfides. The lone pair of electrons functions as a
Bronstad-Lowry base (proton acceptor) as well as a Lewis base
(electron-donor). This pair of electrons on the atom makes it
vulnerable to oxidation in manners similar to sulfides.
[0055] As disclosed herein oxidation feedstock is contacted with an
immiscible phase comprising at least one organic peracid which
contains the --OOH substructure or precursors of organic peracid,
and the liquid reaction mixture is maintained substantially free of
catalytic active metals and/or active metal-containing compounds
and under conditions suitable for oxidation of one or more of the
sulfur-containing and/or nitrogen-containing organic compounds.
Organic peracids for use in this invention are preferably made from
a combination of hydrogen peroxide and a carboxylic acid.
[0056] With respect to the organic peracids the carbonyl carbon is
attached to hydrogen or a hydrocarbon radical. In general such
hydrocarbon radical contains from 1 to about 12 carbon atoms,
preferably from about 1 to about 8 carbon atoms. More preferably,
the organic peracid is selected from the group consisting of
performic acid, peracetic acid, trichloroacetic acid, perbenzoic
acid and perphpthalic acid or precursors thereof. For best results
processes of the present invention employ peracetic acid or
precursors of peracetic acid.
[0057] Broadly, the appropriate amount of organic peracid used
herein is the stoichiometric amount necessary for oxidation of one
or more of the sulfur-containing and/or nitrogen-containing organic
compounds in the oxidation feedstock and is readily determined by
direct experimentation with a selected feedstock. With a higher
concentration of organic peracid, the selectivity generally tends
to favor the more highly oxidized sulfone which beneficially is
even more polar than the sulfoxide.
[0058] Applicants believe the oxidation reaction involves rapid
reaction of organic peracid with the divalent sulfur atom by a
concerted, non-radical mechanism whereby an oxygen atom is actually
donated to the sulfur atom. As stated previously, in the presence
of more peracid, the sulfoxide is further converted to the sulfone,
presumably by the same mechanism. Similarly, it is expected that
the nitrogen atom of an amino is oxidized in the same manner by
hydroperoxy compounds.
[0059] The statement that oxidation according to the invention in
the liquid reaction mixture comprises a step whereby an oxygen atom
is donated to the divalent sulfur atom is not to be taken to imply
that processes according to the invention actually proceeds via
such a reaction mechanism.
[0060] By contacting oxidation feedstock with a peracid-containing
immiscible phase in a liquid reaction mixture maintained
substantially free of catalytic active metals and/or active
metal-containing compounds, the tightly substituted sulfides are
oxidized into their corresponding sulfoxides and sulfones with
negligible if any co-oxidation of mononuclear aromatics. These
oxidation products due to their high polarity, can be readily
removed by separation techniques such as adsorption and extraction.
The high selectivity of the oxidants, coupled with the small amount
of tightly substituted sulfides in hydrotreated streams, makes the
instant invention a particularly effective deep desulfurization
means with minimum yield loss. The yield loss corresponds to the
amount of tightly substituted sulfides oxidized. Since the amount
of tightly substituted sulfides present in a hydrotreated crude is
rather small, the yield loss is correspondingly small.
[0061] Broadly, the liquid phase oxidation reactions are rather
mild and can even be carried out at temperatures as low as room
temperature. More particularly, the liquid phase oxidation will be
conducted under any conditions capable of converting the tightly
substituted sulfides into their corresponding sulfoxides and
sulfones at reasonable rates.
[0062] In accordance with this invention conditions of the liquid
mixture suitable for oxidation during the contacting the oxidation
feedstock with the organic peracid-containing immiscible phase
include any pressure at which the desired oxidation reactions
proceed. Typically, temperatures upward from about 10.degree. C.
are suitable. Preferred temperatures are between about 25.degree.
C. and about 250.degree. C., with temperatures between about
50.degree. and about 150.degree. C. being more preferred. Most
preferred temperatures are between about 115.degree. C. and about
125.degree. C.
[0063] Integrated processes of the invention can include one or
more selective separation steps using solid sorbents capable of
removing sulfoxides and sulfones. Non-limiting examples of such
sorbents, commonly known to the skilled artisan, include activated
carbons, activated bauxite, activated clay, activated coke,
alumina, and silica gel. The oxidized sulfur containing hydrocarbon
material is contacted with solid sorbent for a time sufficient to
reduce the sulfur content of the hydrocarbon phase.
[0064] Integrated processes of the invention can include one or
more selective separation steps using an immiscible solvent having
a dielectric constant suitable to selectively extract oxidized
sulfur-containing and/or nitrogen-containing organic compounds.
Preferably the present invention uses an solvent which exhibits a
dielectric constant in a range from about 24 to about 80. For best
results processes of the present invention employ solvent comprises
a compound is selected from the group consisting of water,
methanol, ethanol, and mixtures thereof.
[0065] Integrated processes of the invention can include one or
more selective separation steps using an immiscible liquid
containing a soluble basic chemical compound. The oxidized sulfur
containing hydrocarbon material is contacted with the solution of
chemical base for a time sufficient to reduce the sulfur content of
the hydrocarbon phase.
[0066] Generally, the suitable basic compounds include ammonia or
any hydroxide, carbonate or bicarbonate of an element selected from
Group I, II, and/or III of the periodic table, although calcined
dolomitic materials and alkalized aluminas can be used. In addition
mixtures of different bases can be utilized. Preferably the basic
compound is a hydroxide, carbonate or bicarbonate of an element
selected from Group I and/or II element. More preferably, the basic
compound is selected from the group consisting of sodium,
potassium, barium, calcium and magnesium hydroxide, carbonate or
bicarbonate. For best results processes of the present invention
employ an aqueous solvent containing an alkali metal hydroxide,
preferably selected from the group consisting of sodium, potassium,
barium, calcium and magnesium hydroxide. In general, an aqueous
solution of the base hydroxide at a concentration on a mole basis
of from about1 mole of base to 1 mole of sulfur up to about 4
moles, of base per mole of sulfur is suitable.
[0067] In carrying out a sulfur separation step according to this
invention, pressures of near atmospheric and higher may be
suitable. For example, pressures up to 100 atmosphere can be
used.
[0068] Processes of the present invention advantageously include
catalytic hydrodesulfurization of the oxidation feedstock to form
hydrogen sulfide which may be separated as a gas from the liquid
feedstock, collected on a solid sorbent, and/or by washing with
aqueous liquid. Where the oxidation feedstock is a product of a
process for hydrogenation of a petroleum distillate to facilitate
removal of sulfur and/or nitrogen from the hydrotreated petroleum
distillate, the amount of peracid necessary for the instant
invention is the stoichiometric amount necessary to oxidize the
tightly substituted sulfides contained in the hydrotreated stream
being treated in accordance herewith. Preferably an amount which
will oxidize all of the tightly substituted sulfides will be
used.
[0069] Useful distillate fractions for hydrogenation in the present
invention consists essentially of any one, several, or all refinery
streams boiling in a range from about 50.degree. C. to about
425.degree. C., preferably 150.degree. C. to about 400.degree. C.,
and more preferably between about 175.degree. C. and about
375.degree. C. at atmospheric pressure. For the purpose of the
present invention, the term "consisting essentially of" is defined
as at least 95 percent of the feedstock by volume. The lighter
hydrocarbon components in the distillate product are generally more
profitably recovered to gasoline and the presence of these lower
boiling materials in distillate fuels is often constrained by
distillate fuel flash point specifications. Heavier hydrocarbon
components boiling above 400.degree. C. are generally more
profitably processed as FCC Feed and converted to gasoline. The
presence of heavy hydrocarbon components in distillate fuels is
further constrained by distillate fuel end point
specifications.
[0070] The distillate fractions for hydrogenation in the present
invention can comprise high and low sulfur virgin distillates
derived from high- and low-sulfur crudes, coker distillates,
catalytic cracker light and heavy catalytic cycle oils, and
distillate boiling range products from hydrocracker and resid
hydrotreater facilities. Generally, coker distillate and the light
and heavy catalytic cycle oils are the most highly aromatic
feedstock components, ranging as high as 80 percent by weight
(FIA). The majority of coker distillate and cycle oil aromatics are
present as mono-aromatics and di-aromatics with a smaller portion
present as tri-aromatics. Virgin stocks such as high and low sulfur
virgin distillates are lower in aromatics content ranging as high
as 20 percent by weight aromatics. Generally, the aromatics content
of a combined hydrogenation facility feedstock will range from
about 5 percent by weight to about 80 percent by weight, more
typically from about 10 percent by weight to about 70 percent by
weight, and most typically from about 20 percent by weight to about
60 percent by weight. In a distillate hydrogenation facility with
limited operating capacity, it is generally profitable to process
feedstocks in order of highest aromaticity, since catalytic
processes often proceed to equilibrium product aromatics
concentrations at sufficient space velocity. In this manner,
maximum distillate pool dearomatization is generally achieved.
[0071] Sulfur concentration in distillate fractions for
hydrogenation in the present invention is generally a function of
the high and low sulfur crude mix, the hydrogenation capacity of a
refinery per barrel of crude capacity, and the alternative
dispositions of distillate hydrogenation feedstock components. The
higher sulfur distillate feedstock components are generally virgin
distillates derived from high sulfur crude, coker distillates, and
catalytic cycle oils from fluid catalytic cracking units processing
relatively higher sulfur feedstocks. These distillate feedstock
components can range as high as 2 percent by weight elemental
sulfur but generally range from about 0.1 percent by weight to
about 0.9 percent by weight elemental sulfur. Where a hydrogenation
facility is a two-stage process having a first-stage
denitrogenation and desulfurization zone and a second-stage
dearomatization zone, the dearomatization zone feedstock sulfur
content can range from about 100 ppm to about 0.9 percent by weight
or as low as from about 10 ppm to about 0.9 percent by weight
elemental sulfur.
[0072] Nitrogen content of distillate fractions for hydrogenation
in the present invention is also generally a function of the
nitrogen content of the crude oil, the hydrogenation capacity of a
refinery per barrel of crude capacity, and the alternative
dispositions of distillate hydrogenation feedstock components. The
higher nitrogen distillate feedstocks are generally coker
distillate and the catalytic cycle oils. These distillate feedstock
components can have total nitrogen concentrations ranging as high
as 2000 ppm, but generally range from about 5 ppm to about 900
ppm.
[0073] The catalytic hydrogenation process may be carried out under
relatively mild conditions in a fixed, moving fluidized or
ebullient bed of catalyst. Preferably a fixed bed of catalyst is
used under conditions such that relatively long periods elapse
before regeneration becomes necessary, for example a an average
reaction zone temperature of from about 200.degree. C. to about
450.degree. C., preferably from about 250.degree. C. to about
400.degree. C., and most preferably from about 275.degree. C. to
about 350.degree. C. for best results, and at a pressure within the
range of from about 6 to about 160 atmospheres.
[0074] A particularly preferred pressure range within which the
hydrogenation provides extremely good sulfur removal while
minimizing the amount of pressure and hydrogen required for the
hydrodesulfurization step are pressures within the range of 20 to
60 atmospheres, more preferably from about 25 to 40
atmospheres.
[0075] According the present invention, suitable distillate
fractions are preferably hydrodesulfureized before being
selectively oxidized, and more preferably using a facility capable
of providing effluents of at least one low-boiling fraction and one
high-boiling fraction.
[0076] Where the particular hydrogenation facility is a two-stage
process, the first stage is often designed to desulfurize and
denitrogenate, and the second stage is designed to dearomatize. In
these operations, the feedstocks entering the dearomatization stage
are substantially lower in nitrogen and sulfur content and can be
lower in aromatics content than the feedstocks entering the
hydrogenation facility.
[0077] Generally, the hydrogenation process useful in the present
invention begins with a distillate fraction preheating step. The
distillate fraction is preheated in feed/effluent heat exchangers
prior to entering a furnace for final preheating to a targeted
reaction zone inlet temperature. The distillate fraction can be
contacted with a hydrogen stream prior to, during, and/or after
preheating. The hydrogen-containing stream can also be added in the
hydrogenation reaction zone of a single-stage hydrogenation process
or in either the first or second stage of a two-stage hydrogenation
process.
[0078] The hydrogen stream can be pure hydrogen or can be in
admixture with diluents such as hydrocarbon, carbon monoxide,
carbon dioxide, nitrogen, water, sulfur compounds, and the like.
The hydrogen stream purify should be at least about 50 percent by
volume hydrogen, preferably at least about 65 percent by volume
hydrogen, and more preferably at least about 75 percent by volume
hydrogen for best results. Hydrogen can be supplied from a hydrogen
plant, a catalytic reforming facility or other hydrogen producing
process.
[0079] The reaction zone can consist of one or more fixed bed
reactors containing the same or different catalysts. Two-stage
processes can be designed with at least one fixed bed reactor for
desulfurization and denitrogenation, and at least one fixed bed
reactor for dearomatization. A fixed bed reactor can also comprise
a plurality of catalyst beds. The plurality of catalyst beds in a
single fixed bed reactor can also comprise the same or different
catalysts. Where the catalysts are different in a multi-bed fixed
bed reactor, the initial bed is generally for desulfurization and
denitrogenation, and subsequent beds are for dearomatization.
[0080] Since the hydrogenation reaction is generally exothermic,
interstage cooling, consisting of heat transfer devices between
fixed bed reactors or between catalyst beds in the same reactor
shell, can be employed. At least a portion of the heat generated
from the hydrogenation process can often be profitably recovered
for use in the hydrogenation process. Where this heat recovery
option is not available, cooling may be performed through cooling
utilities such as cooling water or air, or through use of a
hydrogen quench stream injected directly into the reactors.
Two-stage processes can provide reduced temperature exotherm per
reactor shell and provide better hydrogenation reactor temperature
control.
[0081] The reaction zone effluent is generally cooled and the
effluent stream is directed to a separator device to remove the
hydrogen. Some of the recovered hydrogen can be recycled back to
the process while some of the hydrogen can be purged to external
systems such as plant or refinery fuel. The hydrogen purge rate is
often controlled to maintain a minimum hydrogen purity and remove
hydrogen sulfide. Recycled hydrogen is generally compressed,
supplemented with "make-up" hydrogen, and injected into the process
for further hydrogenation.
[0082] Liquid effluent of the separator device can be processed in
a stripper device where light hydrocarbons can be removed and
directed to more appropriate hydrocarbon pools. Preferably the
separator and/or stripper device includes means capable of
providing effluents of at least one low-boiling liquid fraction and
one high-boiling liquid fraction. Liquid effluent and/or one or
more liquid fraction thereof is subsequently treated to incorporate
oxygen into the liquid organic compounds therein and/or assist by
oxidation removal of sulfur or nitrogen from the liquid products.
Liquid products are then generally conveyed to blending facilities
for production of finished distillate products.
[0083] Operating conditions to be used in the hydrogenation process
include an average reaction zone temperature of from about
200.degree. C. to about 450.degree. C., preferably from about
250.degree. C. to about 400.degree. C., and most preferably from
about 275.degree. C. to about 350.degree. C. for best results.
Reaction temperatures below these ranges can result in less
effective hydrogenation. Excessively high temperatures can cause
the process to reach a thermodynamic aromatic reduction limit,
hydrocracking, catalyst deactivation, and increase energy
costs.
[0084] The hydrogenation process typically operates at reaction
zone pressures ranging from about 400 psig to about 2000 psig, more
preferably from about 500 psig to about 1500 psig, and most
preferably from about 600 psig to about 1200 psig for best results.
Hydrogen circulation rates generally range from about 500 SCF/Bbl
to about 20,000 SCF/Bbl, preferably from about 2,000 SCF/Bbl to
about 15,000 SCF/Bbl, and most preferably from about 3,000 to about
13,000 SCF/Bbl for best results. Reaction pressures and hydrogen
circulation rates below these ranges can result in higher catalyst
deactivation rates resulting in less effective desulfurization,
denitrogenation, and dearomatization. Excessively high reaction
pressures increase energy and equipment costs and provide
diminishing marginal benefits.
[0085] Useful catalyst for the hydrodesulfurization comprise a
component capable to enhance the incorporation of hydrogen into a
mixture of organic compounds to thereby form at least hydrogen
sulfide, and a catalyst support component. The catalyst support
component typically comprises mordenite and a refractory inorganic
oxide such as silica alumina, or silica-alumina. The mordenite
component is present in the support in an amount ranging from about
10 percent by weight to about 90 percent by weight, preferably from
about 40 percent by weight to about 85 percent by weight, and most
preferably from about 50 percent by weight to about 80 percent by
weight for best results. The refractory inorganic oxide, suitable
for use in the present invention, has a pore diameter ranging from
about 50 to about 200 Angstroms and more preferably from about 80
to about 150 Angstroms for best results. Mordenite, as synthesized,
is characterized by its silicon to aluminum ratio of about 5:1 and
its crystal structure.
[0086] Further reduction of such heteroaromatic sulfides from a
distillate petroleum fraction by hydrotreating would require that
the stream be subjected to very severe catalytic hydrogenation
order to convert these compounds into hydrocarbons and hydrogen
sulfide (H.sub.2S), Typically, the larger any hydrocarbon moiety
is, the more difficult it is to hydrogenate the sulfide. Therefore,
the residual organo-sulfur compounds remaining after a
hydrotreatment are the most tightly substituted sulfides.
[0087] Subsequent to desulfurization by catalytic hydrogenation, as
disclosed herein further selective removal of sulfur or nitrogen
from the desulfurized mixture of organic compounds can be
accomplished by incorporation of oxygen into sulfur or nitrogen
containing organic compounds thereby assisting in selective removal
of sulfur or nitrogen from oxidation feedstocks.
General
[0088] Oxygenation of a hydrocarbon product was determined by the
difference between the high precision carbon and hydrogen analysis
of the feed and product. Oxygenation, percent,=(percent C+percent
H).sub.analysis of feed-(percent C+percent H).sub.analysis of
oxygenated product
EXAMPLE 1
[0089] In this example a refinery distillate containing sulfur at a
level of about 500 ppm was hydrotreated under conditions suitable
to produce hydrodesulfurized distillate containing sulfur at a
level of about 130 ppm, which was identified as hydrotreated
distillate 150. Hydrotreated distillate 150 was cut by distillation
into four fractions which were collected at temperatures according
to the following schedule. TABLE-US-00001 Fraction Temperatures,
.degree. C. 1 Below 260 2 260 to 288 3 288 to 316 4 Above 316
[0090] Analysis of hydrotreated distillate 150 over this range of
distillation cut points is shown in Table I. In accordance with
this invention a fraction collected below a temperature in the
range from about 260.degree. C. to about 300.degree. C. splits
hydrotreated distillate 150 into a sulfur-lean, monoaromatic-rich
fraction and a sulfur-rich, monoaromatic-lean fraction.
EXAMPLE 2
[0091] In this example a refinery distillate containing sulfur at a
level of about 500 ppm was hydrotreated under conditions suitable
to produce a hydrodesulfurized distillate containing sulfur at a
level of about 15 ppm, which was identified as hydrotreated
distillate 15.
[0092] Analysis of hydrotreated distillate 15 over the range of
distillation cut points is shown in Table II. In accordance with
this invention a fraction collected below a temperature in the
range from about 260.degree. C. to about 300.degree. C. splits
hydrotreated distillate 15 into a sulfur-lean, monoaromatic-rich
fraction and a sulfur-rich, monoaromatic-lean fraction.
TABLE-US-00002 TABLE I ANALYSIS OF DISTILLATION FRACTIONS OF
HYDROTREATED DISTILLATE 150 Fraction Number Item 1 2 3 4 Total
Weight, % 45 21 19 16 100 Sulfur, ppm 11.7 25 174 580 133 Mono-Ar,
% 40.7 26.3 15.6 14.0 28.8 Di-Ar, % 0.4 5.0 5.4 5.6 3.1 Tri-Ar, % 0
0 0 0.8 0.1 Mono-Ar is mono-aromatics. Di-Ar is di-aromatics.
Tri-Ar is tri-aromatics.
[0093] TABLE-US-00003 TABLE II ANALYSIS OF DISTILLATION FRACTIONS
OF HYDROTREATED DISTILLATE 15 Fraction Number Item 1 2 3 4 Total
Weight, % 53 16 20 11 100 Sulfur, ppm 1 2 13 80 12.3 Mono-Ar, %
35.8 20.9 14.8 12.0 5.6 Di-Ar, % 1.3 8.0 7.4 5.6 4.0 Tri-Ar, % 0 0
0 1.4 0.2 Mono-Ar is mono-aromatics. Di-Ar is di-aromatics. Tri-Ar
is tri-aromatics.
EXAMPLE 3
[0094] This example describes a catalytic oxygenation according to
the invention of a hydrotreated refinery distillate identified as
S-25. A stirred reactor, having a nominal volume of 5 gallons and
built of titanium, was charged with 18 lbs of S-25 and 18.81 grams
of cobalt(II) acetylacetonate hydrate (Aldrich catalog no.
34,461-5, which contained 22.92 percent by weight cobalt). This
provided a cobalt(II) acetylacetonate hydrate concentration of 0.23
percent by weight in the hydrotreated distillate, or 527 ppm cobalt
in the distillate.
[0095] The reactor was then sealed, purged with nitrogen gas and
pressurized to 100 psig. The agitation speed was 700 rpm. Heat was
applied to the walls of the reactor via exterior electric heaters
in order to preheat the reactor contents to 128.degree. C.
[0096] Oxygenation of the reactor contents was initiated by
introducing an oxygen-containing gas stream (about 8 percent
molecular oxygen and 92 percent by molecular nitrogen volume) at an
initial flow rate of 50 scfh into the bottom of the reactor
underneath the bottom impeller of the agitator. This caused the
liquid level within the reactor to rise as the gas became dispersed
throughout the liquid. The gas leaving the top of the liquid level
was mostly disengaged from the liquid within the upper portion of
the reactor and flowed downstream through a water-cooled overhead
condenser, through a gas-liquid separator (knock-out tank) and
through a pressure-regulating control valve. A portion of this vent
gas stream passed through several on-line analyzers which
continuously monitored the concentrations of oxygen, carbon
monoxide and carbon dioxide in the vent gas during the course of
the batch oxygenation. Any liquid which was entrained with the gas
stream leaving the oxygenation reactor was collected in the
gas-liquid separator and continuously pumped back into the top of
oxidation reactor via a gear pump.
[0097] Gas pressure in the oxygenation reactor was automatically
controlled via a feedback control loop which adjusted a
pressure-regulating control valve to achieve the desired reactor
pressure. Temperature in the reactor was controlled via a
controlled flow of distilled water through a cooling coil located
in the lower portion of the oxygenation reactor. Flow of distilled
water was controlled by manually adjusting a micro-metering valve
upstream of the cooling coil. The cooling coil was operated at
atmospheric pressure so that the distilled water entering the
cooling coil flashed to steam, thereby removing heat from the
reaction mixture via the vaporization of water. The oxygen
concentration in the vent gas stream was controlled by adjusting
the flow rate of oxygen-containing gas entering the oxygenation
reactor. The flow rate of oxygen-containing gas was measured via a
mass flow meter and controlled via a flow control valve.
[0098] After the initiation of oxygenation, the flow of
oxygen-containing gas was slowly increased as the reaction
temperature began to increase and the rate of oxygen consumption
increased. After 10 minutes, the reaction temperature reached about
141.degree. C. and the gas feed rate was 200 scfh with no oxygen
detected in the vent gas. After 20 minutes, the reaction
temperature reached about 142.degree. C. with a gas feed rate of
375 scfh and 0.87 percent by volume oxygen in the vent gas. After
26 minutes, the reaction temperature was about 141.degree. C. with
a gas feed rate of 423 scfh and 1.36 percent by volume oxygen in
the vent gas.
[0099] After 36 minutes, the batch reaction was ended by stopping
the flow of oxygen-containing gas and purging the reactor with
flowing nitrogen. As the reaction temperature decreased, the flow
of distilled water to the cooling coil was stopped. The reactor was
then depressurized and the contents of the reactor was emptied into
a 5 gallon container. The product consisted of two layers of liquid
with the bulk layer occupying approximately 95 percent of the total
liquid volume.
[0100] Portions of the untreated bulk layer, identified as GS-25,
were withdrawn for cetane rating and other Analysis. Analysis of
GS-25 determined an oxygenation level of 2.75 percent, a sulfur
level of 10 ppm, a nitrogen level of 7 ppm, and a total acid number
of 10.7 mg KOH/g. The cetane rating of GS-25 was determined to be
59.9, however the cetane rating engine ran roughly. The cetane
rating of the un-oxygenated distillate S-25 was 49.9.
EXAMPLE 4
[0101] This example describes post-oxygenation treatment of GS-25
using aqueous sodium bicarbonate solution which added cetane value.
A portion GS-25 of Example 3 was treated with aqueous sodium
bicarbonate solution, water washed, dried over anhydrous 3A
molecular sieve, and filtered. Filtered material was submitted for
cetane rating and other Analysis. Analysis of the treated portion
of bulk layer determined an oxygenation level of 1.67 percent, a
sulfur level of 7 ppm, a nitrogen level of 9 ppm, and a total acid
number of 2.1 mg KOH/g. The cetane rating of this post-treated bulk
layer was determined to be 62.9, but the cetane rating engine ran
very smoothly in this case.
EXAMPLE 5
[0102] Hydrotreated refinery distillate S-25 was partitioned by
distillation to provide feedstock for catalytic oxygenation using
soluble organic compounds containing a cobalt(II) salt. The
fraction collected below temperatures of about 288.degree. C. was a
sulfur-lean, mono-aromatic-rich fraction identified as S-25-B288,
and the fraction collected above temperatures of about 288.degree.
C. was a sulfur-rich, mono-aromatic-leas fraction identified as
S-25-A288. Analysis of S-25-B288 determined a sulfur content of 10
ppm, a nitrogen content of 5 ppm, and 87.01 percent carbon, 12.98
percent hydrogen with aromatic carbon of 16.5 percent.
[0103] A 300 mL Parr pressure reactor bottom was charged with
S-25-B288 and cobalt(II) bis-acetylacetonate hydrate to provide a
cobalt concentration of 750 ppm. The reactor was sealed, flushed
and filled with nitrogen at 100 psig. Contents of the reactor was
heated with agitation to a set point temperature of about
135.degree. C. After short period at temperature, the nitrogen flow
was replaced by a gaseous mixture of 8 percent molecular oxygen in
nitrogen at a rate of 7 scfh.
[0104] At the end of a 34 minute period of reaction, the flow of
the gaseous mixture (8 percent molecular oxygen in nitrogen) was
replaced with nitrogen. After the reactor cooled the system was
depressured, unsealed, and the oxygenated mixture was identified as
GS-25-B288. A sample of oxygenated mixture GS-25-B288 was dried
over anhydrous sodium sulfate and analyzed.
[0105] Analysis of GS-25-B288 of this example determined a sulfur
content of 3 ppm, i.e. a sulfur reduction of 70 percent,
oxygenation of 3.8 percent, and a total acid number of 7.4 mg
KOH/g.
EXAMPLE 6
[0106] For this example the 5 gallon pressure reactor was charged
with another portion of S-25-B288 and cobalt(II) octoate in mineral
sprits to provide a cobalt concentration of 750 ppm. Oxygenation
was carried out as in Example 3, except that the reaction period
was extended to 39 minutes. Analysis of oxygenated S-25-B288-1
identified as GS-25-B288-1 determined an oxygenation of 4.18
percent, and a total acid number of 11.8 mg KOH/g.
[0107] The procedure of this example was repeated 10 times to
obtain by blending a supply of oxygenated product for
post-treatment testing. The blend of GS-25-B288-X, numbered 1 to 10
was identified as BGS-25-B288. Each oxidation product GS-25-B288-X
consisted of two layers. The top (bulk) layer was decanted from the
lower layer, and the top layer used in post-oxidation
treatments.
[0108] A 4 liter Erlenmeyer flask outfitted with a large magnetic
stirring bar was charged with 1 liter of GS-25-B288-X oxidation
product. The magnetic stirrer was started and approximately 500 mL
of saturated aqueous sodium bicarbonate was carefully added to the
flask. Once all of the aqueous base was added, the stirrer was
turned up to the maximum rate and the mixture of immiscible phases
was permitted to agitate for approximately 20 minutes. At that
point, the agitation was ceased, and the mixture was poured into a
2 liter separatory funnel where the two immiscible phases were
permitted to separate.
[0109] The bottom, aqueous layer was removed and discarded.
Treatment with fresh aqueous sodium bicarbonate was repeated as
necessary to reduce the level of acidic co-products. This extracted
material was transferred to an Erlenmeyer flask and approximately
500 mL of deionized and distilled water added to the flask. After
agitation for approximately 10 minutes, the mixture was again
poured into a separatory funnel and the layers were permitted to
separate. The bottom, aqueous layer was drained and discarded.
[0110] For the next step in the post-treatment process an LC-type
column measuring 3 inches ID.times.24 inches in length was filled
with approximately three liters of dried 3A molecular sieve. The
combined blend from the sodium bicarbonate extractions and wash
treatment, BGS-25-B288, was dripped through the column to remove
any residual water. This material was identified as E6-F and used
for blending in Example 18.
EXAMPLE 7
[0111] For this example the 300 mL Parr pressure reactor bottom was
charged with S-25 and cobalt(II) bis-acetylacetonate hydrate to
provide a cobalt concentration of 543 ppm. Oxygenation of S-25 was
carried out as in Example 5, except that the reaction period was 33
minutes. Analysis of oxygenated S-25 in this example determined a
sulfur content of 11 ppm, i.e. a sulfur reduction of 45 percent, a
nitrogen content of 9 ppm, i.e. a nitrogen reduction of 50 percent,
oxygenation of 3.61 percent, and a total acid number of 7.1 mg
KOH/g.
EXAMPLES 8-11
[0112] Hydrotreated refinery distillate S-25 was partitioned by
distillation to provide feedstock for oxidation using hydrogen
peroxide and acetic acid. The fraction collected below temperatures
of about 300.degree. C. was a sulfur-lean, monoaromatic-rich
fraction identified as S-25-B300. Analysis of S-25-B300 determined
a sulfur content of 3 ppm, a nitrogen content of 2 ppm, and 36.2
percent mono-aromatics, 1.8 percent di-aromatics, for a total
aromatics of 37.9 percent. The fraction collected above
temperatures of about 300.degree. C. was a sulfur-rich,
monoaromatic-poor fraction identified as S-25-A300. Analysis of
S-25-A300 determined a sulfur content of 35 ppm, a nitrogen content
of 31 ppm, and aromatic content was 15.7 percent mono-aromatics,
5.8 percent di-aromatics, and 1.4 percent tri-aromatics, for a
total aromatics of 22.9 percent.
[0113] Into a 250 mL, three-neck round bottom flask equipped with a
reflux condenser, a mechanical agitator, a nitrogen inlet and
outlet, were charged 100 g of S-25-A300. The reactor was also
charged with varying amounts of glacial acetic acid, distilled and
deionized water, and 30 percent aqueous hydrogen peroxide. The
mixture is heated with stirring and under a slight flow of nitrogen
at approximately 93.degree. C. to 99.degree. C. for approximately
two hours. At the end of the reaction period, the agitation ceased
and the contents of the flask rapidly formed into two liquid
layers. A sample of the top layer (organic) was withdrawn and
dehydrated with anhydrous sodium sulfate. Contents of the flask was
stirred and permitted to cool to ambient temperature before
approximately 0.1 g of manganese dioxide is added to decompose any
residual hydrogen peroxide. At this point, the mixture was stirred
for an additional 10 minutes before the entire reactor content was
collected.
[0114] Table III gives variables and analytical data which
demonstrate that increasing concentration of acetic acid increases
concentration of total sulfur in the aqueous layer. Increasing
level of acetic acid caused sulfur in the organic layer to decrease
by 35 ppm. These data clearly indicate that an essential element of
the present of invention is the use of organic peracids where the
carbonyl carbon is attached to hydrogen or a hydrocarbon radical.
In general such hydrocarbon radical contains from 1 to about 12
carbon atoms, preferably from about 1 to about 8 carbon atoms.
Acetic acid was shown to extract oxidized sulfur compounds from the
organic phase and into the aqueous phase. Without acetic acid, no
noticable sulfur transfer into the aqueous phase was observed.
TABLE-US-00004 TABLE III EXPERIMENTAL PARAMETERS AND ANALYTICAL
RESULTS FOR OXIDATIONS OF LS-25-A300 EXAMPLE 8 9 10 11
H.sub.2O.sub.2, mL 34 34 34 34 HOAc, mL 0 25 50 75 H.sub.2O, mL 100
75 50 25 Sulfur Aq, ppm <2 <2 13 14 Sulfur Org, ppm 33 30 21
18 H.sub.2O.sub.2 is 30 percent hydrogen peroxide. HOAc is glacial
acetic acid. H.sub.2O is distilled water.
EXAMPLE 12
[0115] Hydrotreated refinery distillate S-25 was partitioned by
distillation to provide feedstock for oxidation using an
immisciable aqueous solution phase containing hydrogen peroxide and
acetic acid. The fraction of S-25 collected above temperatures of
about 316.degree. C. was a sulfur-rich, monoaromatic-poor fraction
identified as S-25-A316. Analysis of S-25-A316 determined a sulfur
content of 80 ppm, and a nitrogen content of 102 ppm.
[0116] A 250 mL, three-neck round bottom flask equipped with a
reflux condenser, a magnetic stir bar or mechanical agitator, a
nitrogen inlet and outlet, was charged with 100 g of the
S-98-25-A316, 75 mL glacial acetic acid, 25 mL water, and 17 mL
(30%) hydrogen peroxide. The mixture was heated to 100.degree. C.
and stirred vigorously under a very slight flow of house nitrogen
for two hours.
[0117] At the end of the reaction period, analysis of the top layer
(organic) found total sulfur and nitrogen of 54 ppm sulfur and 5
ppm nitrogen. Contents of the flask was again stirred and cooled to
room temperature. At room temperature, approximately 0.1 g of
manganese dioxide (MnO.sub.2) was added to decompose any excess
hydrogen peroxide and stirring continued for 10 minutes. The entire
contents of the flask were then poured into a bottle with a vented
cap. Analysis of the bottom layer (aqueous) found 44 ppm of total
sulfur.
EXAMPLE 12a
[0118] A second oxidation of hydrotreated refinery distillate
S-25-A316 was conducted as described in Example 12 by charging 100
mL glacial acetic acid, but no water. The organic layer was found
to contain 27 ppm sulfur and 3 ppm nitrogen. The aqueous layer
contained 81 ppm sulfur.
EXAMPLE 12b
[0119] The entire contents of the flask from both Example 12 and
Example 12a were combined. A bottom layer was then removed, leaving
behind a combined organic layer from both experiments. The organic
layer was dried over anhydrous sodium sulfate to remove any
residual water from the process. After the spent sodium sulfate was
removed via vacuum filtration, the filtrate was percolated through
enough alumina so that the filtrate to alumina ratio ranged from
7:1 to 10:1. Analysis of organic layer emerging from the alumina
was 32 ppm of total sulfur and 5 ppm of total nitrogen.
EXAMPLE 13
[0120] A hydrotreated refinery distillate identified as S-150 was
partitioned by distillation to provide feedstock for oxidations
using peracid formed with hydrogen peroxide and acetic acid.
Analysis of S-150 determined a sulfur content of 113 ppm, and a
nitrogen content of 36 ppm. The fraction of S-98 collected above
temperatures of about 316.degree. C. was a sulfur-rich,
monoaromatic-poor fraction identified as S-150-A316. Analysis of
S-150-A316 determined a sulfur content of 580 ppm and a nitrogen
content of 147 ppm.
[0121] A 3 liter, three neck, round bottom flask equipped with a
water-jacketed reflux condenser, a mechanical stirrer, a nitrogen
inlet and outlet, and a heating mantel controlled through a variac,
was charged with 1 kg of S-150-A316, 1 liter of glacial acetic acid
and 170 mL of 30 percent hydrogen peroxide.
[0122] A slight flow of nitrogen was initiated and this gas then
slowly swept over the surface of the reactor content. The agitator
was started to provide efficient mixing and the contents were
heated. Once the temperature reaches 93.degree. C., the contents
were held at this temperature for reaction time of 120 minutes.
[0123] After the reaction time had elapsed, the contents continued
to be stirred while the heating mantel turned off and removed. At
approximately 77.degree. C., the agitator was stopped momentarily
while approximately 1 g of manganese dioxide (MnO.sub.2) was added
through one of the necks of the round bottom flask to the biphasic
mixture to decompose any unreacted hydrogen peroxide. Mixing of the
contents with the agitator was then resumed until the temperature
of the mixture was cooled to approximately 49.degree. C. The
agitation was ceased to allow both organic (top) and aqueous
(bottom) layers to separate, which occurred immediately.
[0124] The bottom layer was removed and retained for further
analysis in a lightly capped bottle to permit the possible
evolution of oxygen from any undecomposed hydrogen peroxide.
Analysis of the bottom layer was 252 ppm of sulfur.
[0125] The reactor was cautiously charged with 500 mL of saturated
aqueous sodium bicarbonate to neutralize the organic layer. After
the bicarbonate solution was added, the mixture was stirred rapidly
for ten minutes to neutralize any remaining acetic acid. The
organic material was dried over anhydrous 3A molecular sieve.
Analysis of the dry organic layer, identified as PS-150-A316, was
143 ppm of sulfur, 4 ppm of nitrogen, and a total acid number of
0.1 mg KOH/g.
EXAMPLE 14
[0126] A 500 mL separatory funnel was charged with 150 mL of
PS-150-A316 and 150 mL of methanol. The funnel was shaken and then
the mixture was allowed to separate. The bottom methanol layer was
collected and saved for analytical testing. A 50 mL portion of the
product was then collected for analytical testing and identified as
sample ME14-1.
[0127] A 100 mL portion of fresh methanol was added to the funnel
containing the remaining 100 mL of product. The funnel was again
shaken and the mixture was allowed to separate. The bottom methanol
layer was collected and saved for Analytical testing. A 50 mL
portion of the methanol extracted product was collected for
analytical testing and identified as sample ME14-2.
[0128] Into the remaining 50 mL of product in the funnel, 50 mL of
fresh methanol was added. The funnel was again shaken and the two
layers were allowed to separate. The bottom methanol layer was
collected and saved for analytical testing. 50 mL of the product is
collected for analytical testing and identified as sample
ME14-3.
[0129] The Analytical results obtained for this example are shown
in Table IV. TABLE-US-00005 TABLE IV REDUCTION OF SULFUR &
TOTAL ACID NUMBER BY METHANOL EXTRACTIONS TAN, Sulfur, Sample mg
KOH/g ppmw PS-150-A316 0.11 143 ME11-1 0.02 35 ME11-2 0.02 14
ME11-3 0.02 7
[0130] These results clearly show that methanol was capable of
selectively removing oxidized sulfur compounds. Additionally,
acidic impurities were also removed by methanol extraction.
EXAMPLE 15
[0131] A separatory funnel was charged with 50 mL of PS-150-A316
and 50 mL water. The funnel was shaken and the layers were allowed
to separate. The bottom water layer was collected and saved for
analytical testing. The hydrocarbon layer was collected for
analytical testing and identified as E15-1W. Table II presents
these results. TABLE-US-00006 TABLE V REDUCTION OF SULFUR BY WATER
EXTRACTION TAN Nitrogen Sulfur Sample mg KOH/g ppmw ppmw
PS-150-A316 0.11 4 143 E12-1W -- 5 100
[0132] The water extraction results show that water was useful in
removing oxidized sulfur compounds from the distillate.
EXAMPLE 16
[0133] Five hundred grams of PS-150-A316 were percolated through 50
grams of anhydrous acidic alumina. The collected product was
idntified as E16-1A and analyzed. The data are presented in Table
III. TABLE-US-00007 TABLE VI REDUCTION OF SULFER AND NITROGEN BY
ALUMINA TREATMENT Nitrogen Sulfur Sample ppmw ppmw PS-150-A316 4
143 E13-1A 2 32
[0134] These data demonstrate that alumina treatment was also
effective in the removal of oxidized sulfur and nitrogen compounds
from the distillate.
[0135] Analysis was conducted on alumina treated material E16-1A
and compared with the PS-150-A316. The analysis showed an absence
of any dibenzothiophene in the products, while the feed contained
about 3,000 ppm of this impurity.
EXAMPLE 17
[0136] Hydrotreated refinery distillate S-25 was partitioned by
distillation to provide a feedstock for oxidations using peracid
formed with hydrogen peroxide and acetic acid. The fraction of S-25
collected below temperatures of about 288.degree. C. was a
sulfur-lean, monoaromatic-rich fraction identified as S-DF-B288.
The fraction of S-25 collected above temperatures of about
288.degree. C. was a sulfur-rich, monoaromatic-poor fraction
identified as S-DF-A288. Analysis of S-DF-A288 determined a sulfur
content of 30 ppm.
[0137] A series of oxidation runs were conducted as described in
Example 13 and the products combined to provide amounts of material
needed for cetane rating and chemical analysis. A flask equipped as
in Example 13 was charged with 1 kg of S-DF-A288, 1 liter of
glacial acetic acid, 85 mL of deionized and distilled water and 85
mL of 30 percent hydrogen peroxide.
[0138] In one procedure a batch of dried oxidized distillate was
percolated through a second column packed with 250 mL of dried,
acidic alumina (150 mesh). The distillate to alumina ratio was
about 4:1 (v/v). The alumina waa used for approximately 4 batches
of 1,000 mL, and replaced.
[0139] In another procedure approximately 100 grams of alumina was
placed in a 600 mL Buchner funnel equipped with a fritted disc
(fine). Dried distillate was poured over the alumina and more
quickly treated as the vacuum draws the distillate through the
alumina in a shorter time.
[0140] Every batch of post-alumina treated material was submitted
for total sulfur analysis to quantify the sulfur removal efficiency
from the feed. All alumina treated materials had a sulfur
concentration of less than 3 ppmw, and in general about 1 ppmw
sulfur. A blend of 32 batches of alumina treated material was
identified as BA-DF-A288.
EXAMPLE 18
[0141] Alumina treated materials BA-DF-A288 from Example 17 and
oxygenated material E6-F from Example 6 were blended to produce
fuel DF-GP. Results of testing and analysis of fuel DF-GP are
presented in Table VIII. TABLE-US-00008 TABLE VII Fuel Blended from
Oxygenated Low-Boiling and Oxidative Desulfurized High-Boiling
Fractions and Alumina Treatment Analysis Fuel DF-GP S-25 Total Acid
Number 1.2 <0.01 mg KOH/g Sulfur, ppmw <1 20 Nitrogen, ppmw
1.5 13 Cetane Number 56 50 Spec. Gravity @ 16.degree. C. 0.86 0.84
Heat of Combustion 137,820 137,450 (Btu/gal) Oxygenation, Percent
1.99
EXAMPLE 19
[0142] Another portion of S-25-B288 was oxygenated by the method
described in Example 5. For this example, the 300 mL Parr pressure
reactor bottom was charged with S-25-B288 (125 g) and cobalt(II)
bis-acetylacetonate hydrate (0.41 g). A sample of oxygenated
mixture, identified as GS-25-B288a, was dried over anhydrous sodium
sulfate and analyzed. Analysis of GS-25-B288a determined a sulfur
content of 4 ppm, and oxygenation of 3.52 percent.
EXAMPLE 20
[0143] The procedure of Example 19 was repeated twice, except that
cobalt (II) octanoate/2-ethylhexanoate was the source of cobalt (6
percent by weight of cobalt in mineral spirits). The weight of
catalyst solution charged was 0.78 grams. Analysis of oxygenated
material produced by the first repeat run determined a sulfur
content of 3 ppm, and oxygenation of 3.58 percent, and for the
second repeat run a sulfur content of 2 ppm, and oxygenation of
3.44 percent.
EXAMPLE 21
[0144] Oxygenated materials GS-25-B288, GS-25-B288a, and materials
of both repeat runs of Example 20 were combined, and the combined
material identified as composite GS-21. Analysis of this
composition determined a total oxygenation level of 1.56 percent.
Distrbution of oxygen in GS-21 according to the preferred classes
of aryl structures is presented in Table VIII. TABLE-US-00009 TABLE
VIII Oxygen, Percent by Aryl Oxygenates Weight of GS-21 Type I 0.57
Type II 0.31 Type III 0.31 Type IV 0.17 Type V 0.11 Type VI 0.06
Type VII 0.02 Type VIII 0.01
EXAMPLE 22
[0145] This experiment describes treatment of composite GS-21 for
blending with an oxidatively desulfurized distillate fraction.
Using a separatory funnel, 396.98 grams of GS-21 was extracted with
three 200 mL portions of saturated, aqueous sodium bicarbonate. The
aqueous sodium bicarbonate washes were discarded. The organic (top)
layer was then washed with three 200 mL of distilled 10 and
deionized water. The water washes were discarded. The organic
material was then centrifuged to remove any remaining water. The
washed GS-21 material was then dried over anhydrous 3 A molecular
sieve. Treated GS-21 was separated from the sieve by filtration
(Millipore, Type LC, 10 micron). Analytical results are presented
in Table IX. TABLE-US-00010 TABLE IX Analysis Results Total Acid
Number (mg KOH/g) 1.25 Cobalt (ppmw) <0.6 Total Nitrogen (ppmw)
5 Total Sulfur (ppmw) 1
EXAMPLE 23
[0146] Into a three liter, three-neck round bottom flask equipped
with a reflux condenser, a mechanical agitator, a nitrogen inlet
and outlet, were charged 814 g of S-25-A288. The reactor was also
charged with 770 mL of glacial acetic acid and 170 mL 30 percent
aqueous hydrogen peroxide. The mixture was heated with stirring and
under a slight flow of nitrogen at approximately 93.degree. C. for
approximately two hours. After the reaction period, the flask and
contents were cooled, and during the cooling period approximately 1
g of manganese dioxide (MnO.sub.2) was added to the round bottom
flask to decompose any unreacted hydrogen peroxide. When the
agitation ceased, the contents of the flask rapidly formed into two
liquid layers. The aqueous (bottom) layer was removed from the
flask. The organic layer was treated with 500 mL of saturated
aqueous sodium bicarbonate solution. Again the aqueous (bottom)
layer was removed from the flask. The washed material was then
dried over anhydrous 3 A molecular sieve, separated from the sieve
by filtration, and identified as PS-23.
EXAMPLE 24
[0147] This experiment describes treatment of PS-23 for blending
with treated GS-19. Using a separatory funnel, 680 grams of PS-23
was treated with 680 grams of methanol. The mixture was shaken for
one minute and the two layers were permitted to separate. The
bottom layer (product layer) was collected and the top (methanol)
layer was discarded. The product layer was treated two more times
with a 680 gram portions of methanol. Each time, the methanol layer
was discarded.
[0148] The methanol treated product was further treated with an
equal portion by weight of deionized and distilled water in a
separatory funnel. The mixture was shaken for approximately one
minute to wash the product. The mixture was permitted to separate
into two layers. The bottom, water layer was drained and discarded.
A centrifuge was employed to remove the residual amount of water
remaining in the organic layer. This oxidatively desulfurized
material was identified as PS-24 and submitted for analysis.
Analytical results are presented in Table X. TABLE-US-00011 TABLE X
Analysis Results Total Acid Number (mg KOH/g) <0.01 Total
Nitrogen (ppmw) 2 Total Sulfur (ppmw) 1 Methanol (ppmw) 63.3
Density (g/mL) 0.849
EXAMPLE 25
[0149] A composition was blended using 7 parts by weight of treated
GS-21 to 3 parts by weight oxidatively desulfurized material PS-24
which produced the desired oxygenated, ultralow sulfur composition.
Analysis of this composition determined an oxygenation of 1.82
percent.
[0150] For the purposes of the present invention, "predominantly"
is defined as more than about fifty percent. "Effective amount" is
defined being present in such proportions as to produce a decided,
decisive, or desired measurably affect macroscopic properties of an
associated compound or system. "Substantially" is defined as
occurring with sufficient frequency or being present in such
proportions as to measurably affect macroscopic properties of an
associated compound or system. Where the frequency or proportion
for such impact is not clear, substantially is to be regarded as
about twenty per cent or more. The term "essentially" is defined as
absolutely except that small variations which have no more than a
negligible effect on macroscopic qualities and final outcome are
permitted, typically up to about one percent.
* * * * *