U.S. patent application number 10/310427 was filed with the patent office on 2004-06-10 for anti-static additive compositions for hydrocarbon fuels.
Invention is credited to Henry, Cyrus Pershing JR..
Application Number | 20040107635 10/310427 |
Document ID | / |
Family ID | 32468036 |
Filed Date | 2004-06-10 |
United States Patent
Application |
20040107635 |
Kind Code |
A1 |
Henry, Cyrus Pershing JR. |
June 10, 2004 |
Anti-static additive compositions for hydrocarbon fuels
Abstract
It has been discovered that less expensive, and in some cases
synergistically effective anti-static additive blends may be added
to hydrocarbon fuels to improve the conductivity thereof. The blend
includes an anti-static amount of at least one hydrocarbon soluble
copolymer of an alkylvinyl monomer and a cationic vinyl monomer and
an anti-static amount of at least one hydrocarbon soluble
polysulfone copolymer of at least one olefin and sulfur dioxide.
Optional ingredients include polymeric polyamines and aryl sulfonic
acids.
Inventors: |
Henry, Cyrus Pershing JR.;
(Wilmington, DE) |
Correspondence
Address: |
FAY, SHARPE, FAGAN,
MINNICH & McKEE, LLP
Seventh Floor
1100 Superior Avenue
Cleveland
OH
44114-2518
US
|
Family ID: |
32468036 |
Appl. No.: |
10/310427 |
Filed: |
December 5, 2002 |
Current U.S.
Class: |
44/370 ;
44/374 |
Current CPC
Class: |
C10L 1/2364 20130101;
C10L 1/2225 20130101; C10L 1/2437 20130101; C10L 1/2475 20130101;
C10L 1/146 20130101; C10L 1/1963 20130101 |
Class at
Publication: |
044/370 ;
044/374 |
International
Class: |
C10L 001/24 |
Claims
1. A composition having increased electrical conductivity,
comprising a) a liquid hydrocarbon; b) an anti-static amount of at
least one hydrocarbon soluble copolymer of an alkylvinyl monomer
and a cationic vinyl monomer; and c) an anti-static amount of at
least one hydrocarbon soluble polysulfone copolymer of at least one
olefin and sulfur dioxide.
2. The composition of claim 1 further comprising d) a
polyamine.
3. The composition of claim 2 further comprising e) an aryl
sulfonic acid.
4. The composition of claim 1 further comprising an anti-static
amount of at least two hydrocarbon soluble polysulfone copolymers,
each of at least one olefin and sulfur dioxide.
5. The composition of claim 1 where the weight ratio of copolymer
of an alkylvinyl monomer and a cationic vinyl monomer to
polysulfone copolymer ranges from about 1:5 to about 2.5:1.
6. The composition of claim 1 wherein b) the cationic vinyl monomer
is a cationic quaternary ammonium vinyl monomer.
7. The composition of claim 1 wherein b) the cationic vinyl monomer
is selected from the group consisting of a cationic quaternary
ammonium acrylate monomer and a cationic quaternary ammonium
methacrylate monomer.
8. The composition of claim 1 further comprising a copolymer of an
alkyl vinyl monomer and a nitrile-containing monomer.
9. A composition having increased electrical conductivity,
comprising a) a liquid hydrocarbon; b) an anti-static amount of at
least one hydrocarbon soluble copolymer of an alkylvinyl monomer
and a cationic vinyl monomer, and c) an anti-static amount of at
least one hydrocarbon soluble polysulfone copolymer of at least one
olefin and sulfur dioxide further comprising about 50 mol percent
of units from sulfur dioxide, about 40 to 50 mol percent of units
derived from one or more 1-alkenes each having from about 6 to 24
carbon atoms, and from about 0 to 10 mol percent of units derived
from an olefinic compound having the formula ACH.dbd.CHB wherein A
is a group having the formula --(C.sub.xH.sub.2x)--COOH wherein x
is from 0 to about 17, and B is hydrogen or carboxyl, with the
proviso that when B is carboxyl, x is 0, and wherein A and B
together can be a dicarboxylic anhydride group where the weight
ratio of copolymer of an alkylvinyl monomer and a cationic vinyl
monomer to polysulfone copolymer ranges from about 1:5 to about
2.5:1.
10. The composition of claim 9 further comprising d) a
polyamine.
11. The composition of claim 9 further comprising e) an aryl
sulfonic acid.
12. The composition of claim 9 where in b) the cationic vinyl
monomer is a cationic quaternary ammonium vinyl monomer.
13. The composition of claim 9 where in b) the cationic vinyl
monomer is selected from the group consisting of a cationic
quaternary ammonium acrylate monomer and a cationic quaternary
ammonium methacrylate monomer.
14. A composition for improving the anti-static property of a
liquid hydrocarbon comprising: a) an anti-static amount of at least
one hydrocarbon soluble copolymer of an alkylvinyl monomer and a
cationic vinyl monomer, and b) an anti-static amount of at least
one hydrocarbon soluble polysulfone copolymer of at least one
olefin and sulfur dioxide.
15. The composition of claim 14 further comprising d) a
polyamine.
16. The composition of claim 14 further comprising e) an aryl
sulfonic acid.
17. The composition of claim 14 where the weight ratio of copolymer
of an alkylvinyl monomer and a cationic vinyl monomer to
polysulfone copolymer ranges from about 1:5 to about 2.5:1.
18. The composition of claim 14 further comprising a copolymer of
an alkyl vinyl monomer and a nitrile-containing monomer.
19. A method for improving the anti-static property of a liquid
hydrocarbon comprising: a) providing a hydrocarbon fuel; b) adding
to the hydrocarbon fuel, in any order: i) an anti-static amount of
at least one hydrocarbon soluble copolymer of an alkylvinyl monomer
and a cationic vinyl monomer, and ii) an anti-static amount of at
least one hydrocarbon soluble polysulfone copolymer of at least one
olefin and sulfur dioxide.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to methods and compositions
for increasing hydrocarbon conductivity, and more particularly
relates, in one embodiment, to blends of halogen-free alkylvinyl
monomer and a cationic vinyl monomer copolymer compositions with
polysulfone copolymers that increase the conductivity of liquid
hydrocarbons, such as solvents and fuels, and thereby control the
build-up of potentially hazardous static charges in such liquids,
and to methods of making and using such compositions.
BACKGROUND OF THE INVENTION
[0002] It is widely known that electrostatic charges can be
frictionally transferred between two dissimilar, nonconductive
materials. When this occurs, the electrostatic charge thus created
appears at the surfaces of the contacting materials. The magnitude
of the generated charge is dependent upon the nature of and, more
particularly, the respective conductivity of each material. In
fact, electrostatic charging also occurs when a solid is mixed with
a liquid and when water settles through a hydrocarbon solution. It
is the latter situations that are of greatest interest to the
petroleum industry, for when such charges are built up in or around
flammable liquids, their eventual discharge can lead to incendiary
sparking, and perhaps to a serious fire or explosion.
[0003] While incendiary sparking is an ubiquitous problem in the
petroleum industry, the potential for fire and explosion is
probably at its greatest during product handling, transfer and
transportation. For example, static charges are known to accumulate
in solvents and fuels when they flow through piping, especially
when these liquids flow through high surface area or "fine" filters
and other process controls such as is common during tank truck
filling. Countermeasures designed to prevent accumulation of
electrostatic charges on a container being filled and to prevent
sparks by conducting the container to ground can be employed, such
as container grounding (i.e. "earthing") and bonding. But it has
been recognized that these measures are inadequate to deal
successfully with all of the electrostatic hazards presented by
hydrocarbon fuels.
[0004] Alone, grounding and bonding are not sufficient to prevent
electrostatic build-up in low conductivity, volatile organic
liquids such as distillate fuels like diesel, gasoline, jet fuel,
turbine fuels and kerosene. Similarly, grounding and bonding do not
prevent static charge accumulation in relatively clean (i.e.
contaminant free) light hydrocarbon oils such as organic solvents
and cleaning fluids. This is because the conductivity of these
organics is so low that a static charge moves very slowly through
these liquids and can take a considerable time to reach the surface
of a grounded, conductive container. Until this occurs, a high
surface-voltage potential can be achieved which can create an
incendiary spark, ignition or explosion can thus occur in an
environment of air-hydrocarbon vapor.
[0005] One can directly attack the source of the increased hazard
presented by these low conductivity organic liquids by increasing
the conductivity of the liquid with additives. The increased
conductivity of the liquid will substantially reduce the time
necessary for any charges that exist in the liquid to be conducted
away by the grounded inside surface of the container. Various
compositions are known for use as liquid hydrocarbon additives to
increase the electrical conductivity of these liquids. For example,
in U.S. Pat. Nos. 3,578,421; 3,677,724; 3,807,977; 3,811,848; and
3,917,466 there are described anti-static additives generally of
the alpha-olefin-sulfone copolymer class. In U.S. Pat. No.
3,677,725 an anti-static additive of the alpha-olefin-maleic
anhydride copolymer class is described. Anti-static amines and
methyl vinyl ether-maleic anhydride copolymers are described in
U.S. Pat. No. 3,578,421. Still further, anti-static aliphatic
amines-fluorinated polyolefins are described in U.S. Pat. No.
3,652,238. Similarly, anti-static chromium salts and amine
phosphates are disclosed in U.S. Pat. No. 3,758,283. And, in U.S.
Pat. No. 4,333,741 there are disclosed olefin-acrylonitrile
copolymers for use as anti-static additives in hydrocarbons.
[0006] In the past, halogen-containing compositions introduced into
fuels have played a significant role in achieving anti-static
properties in fuels. While these halogen-containing compositions
are effective as anti-static agents, in certain situations, some
halogen-containing hydrocarbon compounds have been linked to human
and animal health risks as well as environmental degradation.
Legislative enactments, including the 1990 amendment to "The Clean
Air Act" in the United States, signal a trend away from the
continued permissible use in some media of compositions containing
halogens. Even where the use of halogen-containing compositions is
still permitted, stringent regulations often govern the use,
storage and, in particular, the disposal of and/or treatment of
waste streams containing these compositions. Such factors call into
question the continued practical and economic feasibility of
anti-static agents containing halogens without regard to the media
being treated.
[0007] Other prior art compositions have necessarily contained as
much as about 10% (by weight of active ingredients) sulfur in a
form that increases or creates sulfur contamination of the fuels or
other fluids upon their addition thereto. Sulfur in various forms,
such as sulfur dioxide, is known as an undesirable contaminant. Its
undesirability is due to a variety of reasons, including the
problems it causes in handling and its interference with, or
undesirable side effects encountered in, the end uses of the
sulfur-contaminated fluid. While the presence of sulfur in certain
forms in certain fluids is acceptable, it is preferred to minimize
the presence of sulfur.
[0008] U.S. Pat. No. 5,672,183 concerns a composition having
increased electrical conductivity, comprising a liquid hydrocarbon
and an anti-static amount of a hydrocarbon soluble copolymer of an
alkylvinyl monomer and a cationic vinyl monomer. The copolymer has
an alkylvinyl monomer unit to cationic vinyl monomer unit ratio of
from about 1:1 to about 10:1, and an average molecular weight of
from about 800 to about 1,000,000.
[0009] Of course, in addition to the description of these materials
in the patent literature, significant commercial examples exist.
For example, Octel has been selling a range of anti-static
additives under the trade name STADIS.RTM. for many years.
Generally, the STADIS.RTM. products contain an alternating
copolymer made from reacting 1-1-decene with SO.sub.2. The
alternating copolymer is not sold alone, but is formulated with
other components. Typical other formulations are given below:
STADIS.RTM. 125 polysulphone+quaternary ammonium salt (see U.S.
Pat. No. 3,811,848)
STADIS.RTM. 450 polysulphone+quaternary ammonium salt
amine/epichlorhydrin adduct dinonylnaphthylsulphonic acid (see U.S.
Pat. No. 3,917,466)
[0010] Similarly, Baker Hughes Incorporated sells a product
designated TOLAD 3512 (T-3512) which generally can be described as
a copolymer of an alkylvinyl monomer and a cationic vinyl monomer.
It is believed the T-3512 has been primarily used as an anti-static
component in diesel fuel. Diesel fuel, like most fuels, is shipped
through pipelines. These pipelines are "shared" with different
fuels being shipped through a single pipeline in turn. Thus, it is
feasible that if a pipeline has been operated such that a diesel
fuel shipment containing T-3512 is followed by a fuel, such as an
aviation fuel, containing STADIS.RTM. 450, a fuel composition
including both has been achieved.
[0011] However, notwithstanding the availability of STADIS.RTM. and
TOLAD 3512 for many years, no information is available, that
customers have intentionally formulating a fuel with better
anti-static compounds.
[0012] A need has therefore clearly arisen for an effective, low
cost anti-static agent that is useful with a wide variety of
volatile hydrocarbon liquids. It is especially desirable in many
situations that the agent be free of halogens.
SUMMARY OF THE INVENTION
[0013] Accordingly, it is an object of the present invention to
provide a novel liquid hydrocarbon composition having increased
electrical conductivity.
[0014] It is another object of the present invention to provide a
method to effectively reduce accumulated static electrical charge
on a surface of a liquid hydrocarbon.
[0015] In carrying out these and other objects of the invention,
there is provided, in one form, a composition having increased
electrical conductivity, which includes a) a liquid hydrocarbon; b)
an anti-static amount of at least one hydrocarbon soluble copolymer
of an alkylvinyl monomer and a cationic vinyl monomer; and c) an
anti-static amount of at least one hydrocarbon soluble polysulfone
copolymer of at least one olefin and sulfur dioxide.
[0016] Among the several advantages found to be achieved by the
present invention, therefore, may be noted the provision of a
composition and method that provides improved anti-static
properties for a variety of media; the provision of such
composition and method that does not require the use of halogens in
all situations; the provision of such composition and method that
allows use of lower levels of sulfur, reduction of the use of
sulfur in an environmentally unacceptable form; and the provision
of such composition that may be produced with relatively low cost
and waste.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a graphical description of the results of the
Examples.
DETAILED DESCRIPTION OF THE INVENTION
[0018] It has been discovered that a blend of at least one
hydrocarbon soluble copolymer of an alkylvinyl monomer and a
cationic vinyl monomer with at least one hydrocarbon soluble
polysulfone copolymer of at least one olefin and sulfur dioxide can
provide a composition, which can increase the electrical
conductivity of a hydrocarbon fluid that it is mixed with. While
each of these components is known separately as an anti-static
additive for hydrocarbon fuels, it has been discovered that better
conductivity may be obtained with the blends, in some cases, than
can be obtained with each copolymer separately. That is, a
synergistic effect may be observed. Further, the use of a copolymer
of an alkylvinyl monomer and a cationic vinyl monomer in the blend
permits less of the polysulfone copolymer to be used. The
polysulfone copolymer is a relatively more expensive copolymer, and
it contains sulfur. As noted, the proportion of sulfur dioxide is
desired to be minimized. Further, the blends of this invention have
an absence of halogen atoms.
[0019] Within the context of this invention, it should be
understood that the terms "hydrocarbon liquid" and "hydrocarbon
fluid" are synonymous and that these terms encompass conventional
hydrocarbon fuels as well as oxygenated fuels (e.g. methanol,
ethanol, etc.) and blends thereof. It is also expected that the
compositions of the invention may find use as antistatic additives
in fuels to be developed in the future.
[0020] The hydrocarbon soluble copolymer of an alkylvinyl monomer
and a cationic vinyl monomer is described in and may be made by the
procedures of U.S. Pat. No. 5,672,183, the entirety of which is
incorporated by reference herein. In a preferred embodiment, the
copolymer has an alkylvinyl monomer unit to cationic vinyl monomer
unit ratio of from about 1:1 to about 10:1, the copolymer having an
average molecular weight of from about 800 to about 1,000,000. In
another embodiment, the cationic vinyl monomer is a cationic
quaternary ammonium vinyl monomer, and in a preferred embodiment is
a cationic quaternary ammonium acrylate monomer or a cationic
quaternary ammonium methacrylate monomer.
[0021] In a preferred embodiment, the hydrocarbon soluble
polysulfone copolymer of at least one olefin and sulfur dioxide
includes about 50 mol percent of units from sulfur dioxide, about
40 to 50 mol percent of units derived from one or more 1-alkenes
each having from about 6 to 24 carbon atoms, and from about 0 to 10
mol percent of units derived from an olefinic compound having the
formula ACH.dbd.CHB wherein A is a group having the formula
--(C.sub.xH.sub.2x)--COOH wherein x is from 0 to about 17, and B is
hydrogen or carboxyl, with the proviso that when B is carboxyl, x
is 0, and wherein A and B together can be a dicarboxylic anhydride
group. The molecular weight of the polysulfone copolymer may range
from about 5,000 to about 500,000 such as from about 10,000 to
about 500,000, in one non-limiting embodiment, and preferably from
about 10,000 to about 100,000.
[0022] An optional component of the anti-static blend of this
invention is a polymeric polyamine. The polyamine is also an
anti-static agent, and preferably has the formula 1
[0023] where
[0024] R9 is an aliphatic hydrocarbyl group of 8 to 24 carbon
atoms,
[0025] R10 is an alkylene group of 2 to 6 carbon atoms,
[0026] R8 is R9, or an n-aliphatic hydrocarbyl alkylene group of
the formula R9 NHR10,
[0027] a is an integer of 0 to 20,
[0028] b is an integer of 0 to 20,
[0029] c is an integer of 0 to 20, and
[0030] y is an integer of 1 to 2,
[0031] with the proviso that when R8 is R9 then a is an integer of
2 to 20 and b=c=0, and when R is R9 NH--R10 then a is 0 and b+c is
an integer of 2 to 20.
[0032] An arylsulfonic acid may also be present, where the
arylsulfonic acid forms a salt with and to neutralize the
polyamine. This improved the resistance of the formulation to
degradation, which is not desirable. The polyamine and the sulfonic
acid are described in U.S. Pat. No. 3,917,466, the disclosure of
which is incorporated by reference herein. It is preferred that the
polymeric polyamine be present as a salt, particularly a sulfonic
acid salt, for improved resistance to degradation in storage.
[0033] In one preferred embodiment of the invention, at least two
different polysulfone copolymers are employed in the blend. It is
noted that a suitable composition including polysulfone and a
quaternary ammonia salt are also described in U.S. Pat. No.
3,811,848, herein incorporated by reference.
[0034] The weight ratio of the copolymer of an alkylvinyl monomer
and a cationic vinyl monomer to the polysulfone copolymer ranges
from any functional level, to a preferred range being about 1:5 to
about 2.5:1. More preferably the ratio of copolymer of alkyvinyl
monomer and cationic vinyl monomer to polysulphone copolymer will
be less than about 1:1.
[0035] It will be appreciated that it is difficult to predict in
advance what an effective amount of antistatic additive composition
should be used in any particular hydrocarbon liquid since the
effective amount would be dependent upon a number of interrelated
factors including, but not necessarily limited to, the nature of
the hydrocarbon liquid, the proportions and types of copolymers
used in the antistatic additive composition, the effects of other
additives in the liquid, etc. Nevertheless, to give a general,
non-limiting indication of the expected effective ranges, the total
amount of active additive required may be less than 2.0 mg/l,
although concentrations of about 1.5 mg/l are considered to be
adequate. Preferably, in some embodiments, effective amounts range
from about 0.6-1.2 mg/l. It is generally desirable to use lower
values of concentration, primarily for economic reasons, but also
to prevent additive interference with end uses of the treated
liquid. Also, lower concentrations are less likely to cause the
treated fuel to take up water, as can occur under some conditions
when surface-active chemicals are present.
[0036] The method of increasing the conductivity of the fuel
comprises the addition of one of the above compositions to the fuel
or hydrocarbon solvent in a concentration effective to increase the
conductivity of the fuel or solvent. The compositions of this
invention may be preformulated and added to the fuel or solvent all
at once, or the various components can be added separately in any
sequence. This method can be carried out efficiently with
conventional blending and/or mixing equipment, which is widely
available and used in the fuel industry.
[0037] This invention therefore achieves anti-static properties in
fuels by using compositions that are inexpensive to manufacture,
and for preferred embodiments, the constituents are readily
available and inexpensive. Common processing equipment can be used,
and if a halogen-free form is employed, the need for treatment of
hazardous waste halogen-containing by products is eliminated.
Normal combustion of fuel treated with preferred additive
compositions of this invention is not adversely affected and does
not produce hazardous products such as dioxin or other hazardous
halogenated products. Moreover, the very low levels of sulfur in
these anti-static compositions result in a product that is more
environmentally acceptable than commercially available products
containing higher levels of sulfur, particularly sulfur in more
offensive forms.
[0038] The following examples describe preferred embodiments of the
invention. Other embodiments within the scope of the claims herein
will be apparent to one skilled in the art from consideration of
the specification or practice of the invention as disclosed herein.
It is intended that the specification, together with the examples,
be considered exemplary only, with the scope and spirit of the
invention being indicated by the claims, which follow the examples.
For example, specific combinations of copolymers, other than those
specifically tried, in other proportions or ratios or added in
different ways, falling within the claimed parameters, but not
specifically identified or tried in a particular composition to
improve the polymerization inhibition herein, are anticipated to be
within the scope of this invention. In the examples all percentages
are given on a weight basis unless otherwise indicated.
EXAMPLES
[0039] Evaluation of the Effect of TOLAD 3512 on the Conductivity
of a Jet Fuel Pre-Treated with STADIS.RTM. 450
[0040] Examples are prepared in which a jet fuel was treated with
STADIS.RTM. 450, obtained from Octel Starreon. The STADIS.RTM. 450
can be described as a composition of polysulphone+quaternary
ammonium salt+amine/epichlorohydrin adduct dinonylnaphthylsulphonic
acid. STADIS.RTM. 450 was added to achieve a concentration of 0.50
mg/l. TOLAD 3512, obtained from STADISBaker-Petrolite, can be
generally described ascan be generally described as an alkylvinyl
co-polymer. TOLAD 3512 was added to the STADIS.RTM. 450 treated
fuel in 0.1 mg/l increments and conductivity of the fuel measured.
The synergistic effect of combining the STADIS.RTM. 450 and TOLAD
3512 can be seen in the following table and in appended figure.
[0041] Fuel Sample: Jet Fuel provided by Petro-Canada Oakville
Refinery
[0042] Initial Fuel Conductivity: 0 pS/m
[0043] Conductivity of Jet Fuel with 0.50 mg/l of STADIS.RTM. 450:
196 pS/m
[0044] Conductivity of Jet Fuel with 0.50 mg/l of STADIS.RTM. 450
and 1.2 mg/l of TOLAD 3512: 589 pS/m
[0045] Conductivity Profile of Jet Fuel Sample Pre-Treated with 0.5
mg/l of STADIS.RTM. 450
1 Incremental Additions of Cumulative mg/l Added TOLAD 3512,
mg/liter of TOLAD 3512 Conductivity, pS/m 0 0 196 0.1 0.1 237 0.1
0.2 297 0.1 0.3 340 0.1 0.4 404 0.1 0.5 418 0.1 0.6 440 0.1 0.7 483
0.1 0.8 507 0.1 0.9 532 0.1 1 556 0.1 1.1 572 0.1 1.2 589
[0046] In view of the above, it will be seen that the several
advantages of the invention are achieved and other advantageous
results attained.
[0047] As various changes could be made in the above methods and
compositions without departing from the scope of the invention, it
is intended that all matter contained in the above description
shall be interpreted as illustrative and not in a limiting
sense.
* * * * *