U.S. patent application number 10/260755 was filed with the patent office on 2004-04-01 for gasoline additive and method of making same.
Invention is credited to Webber, Kenneth M..
Application Number | 20040060228 10/260755 |
Document ID | / |
Family ID | 32029770 |
Filed Date | 2004-04-01 |
United States Patent
Application |
20040060228 |
Kind Code |
A1 |
Webber, Kenneth M. |
April 1, 2004 |
Gasoline additive and method of making same
Abstract
A gasoline additive composed of a plurality of isomers of at
least one of dibutyloxide, dipentyloxide, and butylpetyloxide,
methods of making same comprising reacting at least one monoolefin
with at least one monoalcohol in the presence of an acid catalyst,
and methods of using same.
Inventors: |
Webber, Kenneth M.;
(Friendswood, TX) |
Correspondence
Address: |
LYONDELL CHEMICAL COMPANY
3801 WEST CHESTER PIKE
NEWTOWN SQUARE
PA
19073
US
|
Family ID: |
32029770 |
Appl. No.: |
10/260755 |
Filed: |
September 30, 2002 |
Current U.S.
Class: |
44/448 ;
44/449 |
Current CPC
Class: |
C10L 1/1852 20130101;
C10L 10/10 20130101 |
Class at
Publication: |
044/448 ;
044/449 |
International
Class: |
C10L 001/18 |
Claims
I claim:
1. An octane enhancing gasoline additive for combustion in a
spark-induced, internal combustion engine, said additive consisting
essentially of a plurality of isomers of at least one of
dibutyloxide, dipentyloxide, and butylpentyloxide.
2. The additive of claim 1 wherein said additive consists
essentially of at least one of a) at least one isomer of
dibutyloxide, b) at least one isomer of dipentyloxide, and c) at
least one isomer of butylpentyloxide.
3. The additive of claim 1 wherein said additive consists
essentially of a mixture of isomers of dibutyloxide, dipentyloxide,
and butylpentyloxide.
4. The additive of claim 3 wherein said additive consists
essentially of at least one isomer of each of two or more of
dibutyloxide, dipentyloxide, and butylpentyloxide.
5. In a method for operating a spark-induced, internal combustion
engine, the improvement comprising introducing into said engine an
effective octane enhancing amount of at least one additive of claim
1 or 3.
6. A method for making a gasoline having an enhanced octane for use
in a spark-induced, internal combustion engine comprising mixing at
least two hydrocarbon streams that boil in the range of from about
77.degree. F. to about 437.degree. F., and blending with said
hydrocarbon streams at least one additive of claim 1 or 3.
7. The method of claim 6 wherein said additive is blended with said
hydrocarbon streams in an effective octane enhancing amount.
8. The method of claim 7 wherein said effective octane enhancing
amount is an amount sufficient to impart to said hydrocarbon stream
mixture a measurable increase in oxygen content.
9. A method for making an octane enhancing gasoline additive
suitable for use in a spark-induced, internal combustion engine
comprising providing a hydrocarbon suitable for combustion in said
engine which contains at least in part at least one monoolefin from
the group having 4 and 5 carbon atoms per molecule and, hydrolyzing
part of at least one of said monoolefin in the presence of an acid
catalyst to the corresponding monoalcohol, leaving a remainder of
unreacted monoolefins, reacting a portion of said monoalcohol with
the remainder of said monoolefin in the presence of an acid
catalyst to form a product containing at least one of dibutyloxide,
dipentyloxide, and bulylpentyloxide, thereby rendering said
hydrocarbon suitable for use as said gasoline additive.
10. The method of claim 9 wherein said monoolefin is at least one
selected from the group consisting of 1-butene, 2-butene,
iso-butene, 1-pentene, 2-pentene, iso-pentene and said
corresponding monoalchol is at least one selected from the group
consisting of normal butyl alcohol, sec butyl alcohol, isobutyl
alcohol, normal pentyl alcohol, sec pentyl alcohol, and isopentyl
alcohol.
11. The method of claim 9 wherein unreacted olefin is separated
from said product and returned to said hydrolyzing step to form
additional monoalcohol.
12. The method of claim 9 wherein the same acid catalyst is
employed for all said reaction steps.
13. The method of claim 10 wherein said reaction steps are each
carried out at a temperature of from about 120 to about 250.degree.
F., a pressure of from about 25 to about 750 psig, a weight hour
space velocity of from about 0.25 to about 10 h.sup.-1, a mole
ratio of monoolefin to water of from about 0.4/1 to about 10/1, a
mole ratio of monoalcohol to monoolefin of from about 0.25/1 to
about 10/1, and a catalyst selected from the group consisting of
acidic resins and acidic inorganic solids.
14. A method for making an octane enhancing gasoline additive
suitable for use in a spark-induced, internal combustion engine
comprising providing a hydrocarbon suitable for combustion in said
engine which contains at least in part at least one monoalcohol
selected from the group having 4 and 5 carbon atoms per molecule,
and at least one iso-monoolefin selected from the group having 4
and 5 carbon atoms per molecule, reacting said at least one
monoalcohol with said at least one iso-monoolefin in the presence
of an acid catalyst to form at least one of dibutyloxide,
dipentyloxide, and butylpentyloxide, whereby a mixture of isomers
of same is formed in said hydrocarbon.
15. The method of claim 14 wherein said monoalcohol is at least one
selected from the group consisting of normal butyl alcohol, sec
butyl alcohol, iso-butyl alcohol, normal pentyl alcohol, sec pentyl
alcohol, and iso-pentyl alcohol, and said at least one
iso-monoolefin is at least one selected from the group consisting
of iso-butylene and iso-pentylene.
16. The method of claim 14 wherein said reaction is carried out at
a temperature of from about 120 to about 200.degree. F., a pressure
of from about 25 to about 750 psig, a weight hour space velocity of
from about 0.25 to about 10 h.sup.-1, a mole ratio of monoalcohol
to iso-monoolefin of from about 0.25/1 to about 10/1, and a
catalyst selected from the group consisting essentially of acidic
resins and acidic in organic solids.
17. The method of claim 14 wherein said at least one monoalcohol is
formed by first hydrolyzing at least part of said at least one
monoolefin.
18. A method for making an octane enhancing gasoline additive
comprising providing a mixture of at least one normal monoolefin,
at least one iso-monoolefin, and at least one monoalcohol, and
reacting same in the presence of an acidic catalyst to form at
least one isomer of dibutyloxide, dipentayloxide, and
butylpentyloxide.
19. The method of claim 18 wherein said at least one monoalcohol is
formed by first hydrolyzing at least part of said at least one
monoolefin.
20. A method for making an octane enhancing gasoline additive
comprising providing a mixture of at least one normal monoolefin
selected from the group having 4 and 5 carbon atoms per molecule,
and at least one normal monoalcohol selected from the group having
4 and 5 carbon atoms per molecule, and reacting said monoolefin and
monoalcohol in the presence of an acid catalyst to form at least
one isomer from a plurality of dibutyloxide, dipentyloxide, and
butylpentyloxide.
21. The method of claim 20 wherein said at least one monoalcohol is
formed by first hydrolyzing at least part of said at least one
monoolefin.
22. An automotive gasoline suitable for use in a spark-induced,
internal combustion engine containing an effective octane enhancing
amount of at least one additive of claim 1 or 3.
23. In a method for enhancing the performance of a spark-induced,
internal combustion engine, the improvement comprising introducing
into said engine an effective octane enhancing amount of at least
one additive of claim 1 or 3.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to an octane enhancing gasoline
additive for a spark-induced internal combustion engine. It also
relates to various methods for making said additive.
DESCRIPTION OF THE PRIOR ART
[0002] It is well known that certain hydrocarbons containing oxygen
(oxygenates) can enhance (increase) the octane of spark-induced,
internal combustion engine (automotive engine) gasoline when added
thereto. Increasing the octane of a gasoline is also well known to
enhance the performance of automotive engines.
[0003] Oxygenates also help improve the exhaust emission profiles
of automotive engines. This is recognized by the Environmental
Protection Agency, which requires up to 2 percent oxygen in
automotive fuel in certain regions of the United States.
Methyl-tert-butyl ether (MTBE) is widely employed as an oxygenate
additive for automotive fuels for enhancing the octane number of a
fuel, enhancing engine performance, and reducing undesired engine
emissions such as NO.sub.X, CO, and unburned fuel.
[0004] The term "octane" is meant to refer to either of Research
Octane Number (RON) or Motor Octane Number (MON) which are based on
isooctane as the standard with an octane number of 100. For
example, regular automotive gasoline has an average octane number
(RON/2 plus MON/2) of at least 87 and premium fuel an average
octane number of at least 92.
[0005] The term "hydrocarbon" as used herein is meant to refer not
only to an organic chemical molecule that contains hydrogen atoms
and carbon atoms, but also such a molecule that may also contain
oxygen atoms, as well. By this definition, certain classes of
compounds such as alcohols (e.g., ethanol, butanol, etc.) and
ethers (e.g., diethyl ether, dibutyl ether, etc.) are considered to
be hydrocarbons.
[0006] Although widely employed as an oxygenate additive in
automotive fuels, MTBE is quite soluble in water, and when
dissolved in water in even low concentrations may impart to the
water an odor and taste that people find objectionable. Some state
governments are considering banning the use of MTBE in gasoline
because of the potential for fugitive gasoline containing MTBE
reaching water supplies, both surface and subsurface.
[0007] Ethanol has been suggested as a substitute for MTBE, but it
has a vapor pressure greater than MTBE and can adversely impact the
Reid Vapor Pressure of its host gasoline. Also, if ethanol contacts
water after being blended into its host gasoline, it will be
extracted into the water phase. This requires that ethanol be
splash blended into gasoline at local gasoline distribution
terminals rather than at the main gasoline blending facility.
[0008] Accordingly, it is desirable to find a substitute additive
for MTBE that does not have the water solubility problem that MTBE
has, and does not have the vapor pressure and blending problems
that ethanol has.
SUMMARY OF THE INVENTION
[0009] In accordance with this invention there is provided an
oxygenate automotive gasoline additive which can serve as a
substitute for MTBE and ethanol, and which does not suffer from the
deficiencies of MTBE and ethanol as noted above.
[0010] The octane enhancing automotive gasoline additive of this
invention contains a plurality of isomers of at least one of
dibutyloxide, dipentyloxide, and butylpentyloxide.
[0011] The additives within this invention are not nearly as water
soluble as MTBE. The additives are not as volatile as either MTBE
or ethanol, and therefore, will not increase the Reid Vapor
Pressure of their host gasoline. Further, the additives of this
invention are much less water soluble than ethanol and will not
require splash blending, but rather can readily be blended into the
gasoline pool at the main blending facility.
[0012] This invention also provides a plurality of methods for
using and making the additives of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Automotive gasolines are generally composed of a mixture of
at least two hydrocarbon streams boiling at atmospheric pressure in
a temperature 10 range of from about 77.degree. F. to about
437.degree. F. They typically are composed of mixtures of
paraffins, aromatics, and olefins, and may contain numerous
additives such as oxygenates, detergents, corrosion inhibitors, and
the like. Currently gasolines suitable for use (combustion) in an
automotive engine conform to the requirements of ASTM D4B14-89
specifications.
[0014] The additives of this invention contain a plurality (at
least two) isomers of at least one of dibutyloxide (DBO),
dipentyloxide (DPO), and/or butylpentyloxide (BPO).
[0015] Dibutyloxides (C4H90C4H9) include 2-2' oxybisbutane [sec
butyl ether] and both its stereo optical isomers (isomers), and
oxybis(2,2 methylpropane) bis(2 butane) [sec-butyl-tert-butyl
ether].
[0016] Dipentyloxides (C5H110C5H11) include 3,3' oxybispentane[3
pentyl ether]; 3,2' oxybispentane[3 pentyl, 2 pentyl ether];
2,2'oxybispentane[2 pentyl ether]; oxybis(2,2 methylbutane)bis 2
pentane[2 pentyl isoamyl ether]; oxybis(2,2 methylbutane)bis 3
pentane[3 pentyl isoamyl ether]; and isomers thereof.
[0017] The additive(s) of this invention contain at least two,
preferably more than two, of the foregoing compounds by themselves
or in combination with other hydrocarbons suitable for use in an
automotive engine. Such other hydrocarbons can be carriers for the
additive of this invention, other additives for automotive
gasoline, and the like.
[0018] The DBO, DPO, and BPO components of the additive(s) of this
invention will tend to be less soluble in water than MTBE.
Typically, as the number of carbon atoms increases in a homologous
series of a particular species, e.g., dialkyl oxides, the water
solubility decreases. For example, diethyl ether is shown to be
slightly water soluble in "The Handbook of Chemistry and Physics"
(Lide, David R, Editor-in-Chief, CRC Press, 1995). That same
reference teaches that dibutyl ether is insoluble in water.
Therefore, since the DBO, DPO and BPO molecules discussed in this
invention all have more carbon atoms than does MTBE, one familiar
with the art would anticipate the DBO, DPO and BPO molecules to be
less soluble in water than is MTBE.
[0019] The additive(s) of this invention can individually contain
at least one isomer from a plurality (two or more) of DBO, DPO, and
BPO, and/or mixtures of 2 or more isomers of DBO, DPO, and/or
BPO.
[0020] The additives of this invention can be blended in
conventional manner with an automotive fuel to provide an
automotive gasoline suitable for use (combustion) in a
spark-induced, internal combustion engine. One or more additives of
this invention will be blended into such gasolines in an effective
octane enhancing amount, which amount will vary greatly depending
on the particular composition of the host gasoline. Since gasoline
is almost infinitely variable in its hydrocarbon make-up, it is
impossible to quantify the amount of additive(s) to be employed
other than to say the amount is sufficient to enhance the octane of
the host gasoline. It can be also said that an effective amount of
additive can be that which provides a measurable addition of oxygen
to the host gasoline, preferably up to about two weight percent
oxygen based on the total weight of the gasoline, or more if
desired and economically feasible.
[0021] Accordingly this invention contemplates a method of
operating and a method of enhancing the performance of an
automotive engine by introducing into said engine an effective
octane enhancing amount of at least one additive within this
invention and/or an amount effective to make a measurable increase
of oxygen in the gasoline used in said engine.
[0022] This invention also provides an automotive gasoline suitable
for use in an automotive engine which contains an effective octane
enhancing amount of at least one additive of this invention and/or
an amount effective to provide a measurable increase of oxygen in
the gasoline used in said engine.
[0023] This invention also includes a method for making automotive
gasoline having an enhanced octane. Automotive fuels are normally
made by blending or otherwise mixing a plurality, at least two,
hydrocarbon-containing streams to produce an automotive gasoline as
characterized hereinabove. Such blending produces a gasoline
product that is suitable for combustion in an automotive engine as
characterized hereinabove. Such blends can readily be made in or
near an operating refinery in various ways well known in and
obvious to the refining/blending art.
[0024] The additive of this invention can be prepared in a number
of ways. One preferred approach to making the additive of this
invention comprises providing a hydrocarbon stream containing at
least in part at least one monoalcohol selected from the group
having 4 and 5 carbon atoms per molecule (C4/C5 monoalcohol), and
at least one monoolefin, either normal or branched, selected from
the group having 4 and 5 carbon atoms per molecule (C4/C5
monoolefin), and reacting the at least one monoalcohol with the at
least one monoolefin to form at least one of DBO, DPO, BPO to yield
an additive containing in whole or in part a mixture of isomers of
DBO, DPO and/or BPO.
[0025] Another preferred approach is to provide a hydrocarbon
stream containing at least in part at least one, preferably a
mixture, of C4/C5 monoolefins (normal and or branched) such as 1-
or 2-butene, isobutylene, 1-, 2-, or 3-pentene, and isopentylene,
and reacting a part of the monoolefins with water to form a
monoalcohol while leaving a remainder of unhydrolyzed and unreacted
monoolefin. Thereafter the monoalcohols are allowed to further
react with at least a part of the remainder of the monoolefin to
form at least one of DBO, DPO, and BPO. The product is an additive
containing in whole or at least in part a rich mixture of octane
enhancing isomers of DBO, DPO, and/or BPO.
[0026] It should be noted that when a mixture of molecules having
four and five carbon atoms, e.g., monoolefins, is reacted with
another mixture of molecules having four and five carbon atoms,
e.g., monoalcohols, the resulting mixture of reaction products will
contain not only isomers of DBO and DPO wherein the hydrocarbon
chains on either side of the oxygen in a given molecule are the
same in number, but also BPO wherein the hydrocarbon chains on
either side of the oxygen in a given molecule are not the same in
number. Examples of BPO reaction products useful in the additives
of this invention are sec butyl 2 pentyl ether, sec butyl 3 pentyl
ether, 2 pentyl tert butyl ether, sec butyl isoamyl ether, and the
like.
[0027] The hydrolysis step described hereinabove can be carried out
separately from the remaining reaction steps or can be carried out
in the same mixture of reactants thus forming the alcohol reactant
in situ in the original monoolefin mixture. When hydrolysis is
carried out separately, a monoolefin mixture is hydrolyzed at least
in part to the various monoalcohols corresponding to the
monoolefins in the original mixture. Thereafter the hydrolysis
reaction product mixture is reacted with normal monoolefins,
iso-monoolefins, or a mixture of normal monoolefins and
iso-monoolefins.
[0028] All the foregoing approaches for making the additives of
this invention from the hydrolysis reaction through the final
reactions that produce the desired isomers of DBO, DPO, and BPO can
be carried out within the same range of reaction conditions using a
catalyst or a number of catalysts from the same class of catalyst
systems.
[0029] These reaction conditions are a temperature of from about
120 to about 250.degree. F., a pressure of from about 25 to about
750 psig, a weight hourly space velocity of from about 0.25 to
about 10 h.sup.-1 (reciprocal hours), a mole ratio of monoolefin
(normal or branched)/water of from about 0.4/1 to about 10/1, and a
mole ratio of monoalcohol to iso-monoolefin of from about 0.25/1 to
about 10/1.
[0030] The acid catalyst class is useful in the aforesaid reactions
from hydrolysis through the final reactions that form the DBO, DPO
and/or BPO products. The same acid catalyst can be used in all the
reactions or different acid catalysts can be used in different
reaction steps such as when hydrolysis is carried out physically
separately. Suitable acid catalysts are well known and will be
obvious to those skilled in the art, but generally will be acidic
resins and acidic inorganic solids. Suitable specific catalysts
include zeolites, amorphous silica aluminas, aluminophosphates
(AIPO), silicoaluminophosphates (SAPO), metalloaluminophosphates
(MeAPO) titanium aluminophosphates (TAPO), titanium
silicophosphates (TASO), metallosilicoaluminophosphates (MeAPSO),
silicas, aluminas, the acid form of ion exchange resins, and the
acid form of perflourinated ion exchange resins.
[0031] When employing mixtures of C4/C5 monoolefins in the
preparation of additives within this invention various refinery or
petrochemical plant hydrocarbon streams can be used. Suitable
streams include raffinate streams from ethylene stream cracking
operations, isobutylene from tert-butyl alcohol dehydration, C4
streams from refinery catalytic cracking operations, and the
like.
EXAMPLE 1
[0032] Five pounds per hour of a mixture of hydrocarbons comprising
36 weight % (wt%) normal 1- and 2-butenes, 44 wt % isobutylene, and
20 wt % normal and iso-butanes, all wt % based on the total weight
of the mixture, are mixed with 0.7 pounds of water per hour in a
reactor containing five pounds of an acid catalyst composed of
sulfonic acid ion exchange resin. The reactor is operating at about
180.degree. F. and about 500 psig. The weight hourly space velocity
for the hydrocarbons is 1.0 and the weight hourly space velocity of
the water is 0.14 h.sup.-1.
[0033] This process produces a reaction product containing 2.3
pounds of DBO; 1.3 pounds of incompletely reacted alcohols (tert
butyl alcohol and sec butyl alcohol) which are separated and
recycled to the reactor to complete their conversion into DBO; 0.8
pounds of unreacted normal and iso-butenes; and 1.0 pounds of
normal and iso-butanes, 0.1 pounds unreacted water and 1.2 pounds
of heavy by-product (mostly olefinic material with 8 carbon atoms
per molecule).
EXAMPLE 2
[0034] A hydrocarbon stream consisting essentially of 1-butene and
2-butene is mixed at the rate of 3 pounds per hour with water at
the rate of 1 pound per hour in the presence of 3 pounds of an acid
catalyst composed of sulfonic acid ion exchange resin. The
hydrolysis reactor operates at 190.degree. F. and 500 psig, and
produces a hydrocarbon stream product consisting essentially of sec
butyl alcohol. This sec butanol stream is passed at the rate of 3
pounds/hour to an etherefication reactor which is at 160.degree. F.
and 500 psig, and contains 7 pounds of an acid catalyst composed of
sulfonic acid ion exchange resin. A separate hydrocarbon mixture
containing 44 wt. isobutylene and 36 wt % normal butene isomers,
all wt % based on total weight of mixture, is passed at the rate of
5 pounds/hour into said etherefication reactor to mix and react
with the sec butanol stream in the presence of the acid catalyst.
The etherefication reactor produces a hydrocarbon stream comprising
50 wt % of a mixture of sec butyl ether (DBO) and sec butyl tert
butyl ether (DBO), 10 wt % unreacted sec butanol, and 19 wt % of
unreacted normal and iso-butenes (primarily n-butenes), all wt %
based on total weight of the stream. This hydrocarbon stream is
subjected to conventional distillation to separate the sec butanol
and butenes. The sec butanol is returned to the etherefication
reactor to form additional DBO. The distillation separated,
unreacted normal butene isomers are returned to the hydrolysis
reactor to form additional sec butanol. After the foregoing
distillation operation, a DBO product remains which is composed of
26 wt % sec butyl ether and 61 wt % sec butyl tert butyl ether and
13 wt % heavy by-product (mostly olefinic material with 8 carbon
atoms per molecule), all wt % based on the total weight of the DBO
product.
[0035] Reasonable variations and modifications are possible within
the scope of this disclosure without departing from the spirit and
scope of this invention.
* * * * *