Chemical apparatus and process disinfecting – deodorizing – preser – Process disinfecting – preserving – deodorizing – or sterilizing – Deodorizing
Reexamination Certificate
2000-11-03
2003-07-29
Warden, Sr., Robert J. (Department: 1744)
Chemical apparatus and process disinfecting, deodorizing, preser
Process disinfecting, preserving, deodorizing, or sterilizing
Deodorizing
C422S001000, C422S028000, C422S034000, C422S120000
Reexamination Certificate
active
06599472
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to chemical compositions which are metal salts of carboxylic acids herein described, that are soluble in hydrocarbon oils and are used to inactivate odor producing sulfhydryl compounds that are present in hydrocarbon oils or other organic materials, in mixtures containing these materials, and in compositions which come in contact with these materials.
BACKGROUND OF THE INVENTION
The presence of sulfhydryl compounds and particularly hydrogen sulfide in hydrocarbon oils and other organic materials, mixtures containing these materials, and aqueous, solid, or gaseous phases in contact with these materials is an important environmental and safety and health problem in a broad range of industries. Sulfhydryl compounds include H
2
S, organo sulfur compounds containing S—H groups also called mercaptans, thiol carboxylic acids RC(O)SH, dithio acids RC(S)SH, and related compounds.
In the petroleum industry the H
2
S content of crude oils in many areas of the world is high enough to present environmental and safety hazards. Hydrogen sulfide is flammable, corrosive, highly toxic, and a strong irritant. It is produced by sulfate reducing bacteria in the anaerobic environments encountered in oil wells and is highly soluble in the crude oil, from which it is released when the oil is removed from the well. H
2
S may be transferred to oil based drilling fluids when the fluids come in contact with H
2
S rich environments, where it becomes a hazard as the drilling fluid is recirculated from the well to the surface.
Sulfhydryl compounds and their resultant odors are also a problem in metal working environments. Sulfate reducing bacteria are often present in the recirculating metal working fluid systems, and though the bacteria can usually be controlled by the use of biocidal compositions, these biocide systems are difficult to control and monitor, and can occasionally fail, resulting in the offensive and hazardous formation of H
2
S in the fluids. The biocides cannot remove H
2
S after it has formed and thus a back-up means for removing it is desirable. Also, sulfurized oils are widely used in this industry because the sulfur from these compositions reacts with iron and provides lubricating benefits. These oils release undesirable volatile hydrogen sulfide and mercaptan compounds which are not essential to the effectiveness of the lubricants, and it would be desirable to control odors from these compounds.
Sulfhydryl compounds and particularly H
2
S can present environmental and toxicity problems in gaseous phases in confined spaces, as for instance in sewage treatment facilities and particularly in shipping and storage containers for moisture sensitive materials that may emit H
2
S. It would be desirable to have a scavenger that could reduce the H
2
S concentrations in such locations. It would be particularly advantageous to have such a scavenger that is active in the absence of an aqueous phase.
A number of methods have been proposed to control hydrogen sulfide odors in hydrocarbon containing systems.
WO 98/02501 describes bisoxazolidines prepared by the reaction of 1, 2 or 1, 3 amino alcohols containing 3 to 7 carbon atoms with aldehydes containing 4 or fewer carbon atoms. These products can be made oil soluble by the correct choice of starting materials, and react with sulfhydryl compounds present in oil and gas streams to neutralize them. U.S. Pat. No. 5,347,004 describes reaction products of alkoxyalkylene amine, ammonia, and dialkylamines with aldehydes. These products are used to remove hydrogen sulfide from gas streams which are sparged into water solutions of the products. U.S. Pat. No. 6,024,866 describes reaction products of an alkylenepolyamine with formaldehyde which can be made either water or hydrocarbon soluble.
Zinc and iron compounds have been used for this application. U.S. Pat. No. 3,928,211 describes the use of inorganic zinc salts preferably dispersed into aqueous or nonaqueous oil well drilling fluids with an organic dispersant such as lignin containing materials. U.S. Pat. No. 4,147,212 describes a water soluble zinc ammonium carbonate complex used to remove hydrogen sulfide from oils and gases by contact with aqueous solutions of the complex. U.S. Pat. No. 5,792,438 describes the activation of iron oxide by copper oxide to increase the rate of reaction of iron oxide and sulfur compounds. U.S. Pat. No. 4,756,836 discloses the use of chelated iron to oxidize H
2
S to elemental sulfur. The iron chelate is oxygen regenerated and recycled.
Metal salts of carboxylic acids and methods for their production are known. U.S. Pat. No. 2,584,041 describes a method to produce oil soluble metal salts of carboxylic acids in organic solvents by a hydrous two-phase fusion process. U.S. Pat. No. 2,890,232 describes a method for preparing polyvalent metal soaps of higher aliphatic monocarboxylic acids by a slurry process in which the acids are heated and slurried with the metal oxides in the presence of water. U.S. Pat. No. 5,443,698 describes an electrolytic method for synthesizing metal carboxylates.
It is an object of this invention to provide compositions which effectively remove odors caused by sulfhydryl compounds from crude oils, metal working fluids, and other organic materials; and liquid, solid or gaseous phases in contact with these materials.
It is a further object to provide compositions which are readily soluble in the hydrocarbon oils encountered in environments such as oil wells and metal working fluids.
It is a further object to provide compositions which do not contain aldehydes or toxic metals.
It is a further object to provide a method for the removal of odor producing sulfhydryl compounds from crude oils, metal working fluids, and other organic materials; and liquid, solid or gaseous phases in contact with these materials.
BRIEF DESCRIPTION OF THE INVENTION
The oil soluble sulfhydryl compound scavengers of this invention are metal carboxylates or soaps of the formula:
M
n+
R—CO
2
−
)
x
(OH)
n−x
wherein M is a metal ion whose sulfide salt is less than 0.01% soluble in water, n is 2 or 3, x is an integer from 1 to n, and R a hydrocarbyl radical containing from about 4 to about 19 carbon atoms, and mixtures of these compositions.
A method is also provided to control odors produced by sulfhydryl compounds wherein the compositions containing the said sulfhydryl compounds are contacted with the metal carboxylates described above.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The metal carboxylate salts of this invention can be prepared by known methods starting from carboxylic acids or their water soluble salts, and metals, metal oxides or metal salts.
The carboxylic acids used to prepare the compositions of this invention contain from about 5 to about 20 carbon atoms, and are chosen from those which form oil soluble salts with the metal ions of this invention. Preferred are acids which form metal salts that are liquid below about 100° C., and most preferred are those which form metal salts that have pour points below about 25° C. As a rule the formation of low melting salts requires that the carboxylic acids used in the synthesis have highly branched structures. Also preferred are lower molecular weight acids because they are more efficient on a weight basis for the intended application.
Examples of Suitable Acids Include:
1. Neoacids. These are synthesized by reacting under high pressure and at elevated temperature a branched olefin and high-purity carbon monoxide in the presence of an acidic catalyst and water. The resulting acids have a tertiary carbon adjacent to the carboxyl group and are mixtures of isomers of the structure:
wherein R
1
, R
2
, and R
3
are each alkyl radicals containing 1 to about 16 carbon atoms, with the total number of carbon atoms contained in R
1
, R
2
, and R
3
being from about 3 to about 18.
Neoacids with 7 or more carbon atoms are mixtures of isomers. For example, the typical isomer distribution of neodecanoic acid is: R
1
and R
2
are methyl, R
3
is C
6
, 31%; R
1
is methyl, R
2
Chorbaji Monzer R.
Surface Chemists of Florida Inc.
Warden, Sr. Robert J.
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