An absorbent for selective removal of hydrogen sulfide over carbon dioxide from a fluid stream comprises an aqueous solution of a) a tertiary amine, b) a sterically hindered secondary amine of the general formula (I)

##STR00001##

in which R.sub.1 and R.sub.2 are each independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl, with the proviso that at least one R.sub.4 and/or R.sub.5 radical on the carbon atom bonded directly to the nitrogen atom is C.sub.1-4-alkyl or C.sub.1-4-hydroxyalkyl when R.sub.3 is hydrogen; x and y are integers from 2 to 4 and z is an integer from 1 to 4; where the molar ratio of b) to a) is in the range from 0.05 to 1.0, and c) an acid in an amount, calculated as neutralization equivalent relative to the protonatable nitrogen atoms in a) and b), of 0.05 to 15.0%. One preferred amine of the formula I is 2-(2-tert-butylaminoethoxy)ethanol. The absorbent allows a defined H.sub.2S selectivity to be set at pressures of the kind typical in natural gas processing.

The present disclosure provides fuel additives including a quaternary ammonium salt formed by reacting an alkyl carboxylate with a compound formed from a hydrocarbyl substituted acylating agent reacted with a select amine. Also provided herein are fuel compositions including the novel fuel additives and methods of combusting a fuel including the fuel additives herein. The unique quaternary ammonium salts herein are advantageous because they can be made through a simple alkylation process and provide improved detergency at low treat rates by making available a relatively less sterically hindered quaternary nitrogen for detergency activity in the fuel.

The present invention relates to a composition of additives comprising: at least one first compound selected from: (i) copolymers of ethylene and vinyl acetate having a molar mass Mn included in the range ranging from 10,000 to 60,000 g.Math.mol1, optionally grafted by at least one alkyl (meth)acrylate group, the alkyl chain of which is saturated and contains from 12 to 30 carbon atoms; and (ii) polymers comprising at least 90 mol % of units derived from alkyl. (meth)acrylate monomer, the alkyl chain of which is saturated and contains from 18 to 22 carbon atoms; and at least one second compound selected from the modified alkylphenol-aldehyde resins. The invention also relates to the use of this composition of additives for lowering the viscosity of a liquid petroleum product such as a crude oil and for reducing the deposition of paraffins.

Described herein are associative polymers capable of controlling a physical and/or chemical property of non-polar compositions that can be used when the non-polar composition is in a flow, and related compositions, methods and systems. Associative polymers herein described have a non-polar backbone with a longest span having a molecular weight that remains substantially unchanged under the flow conditions and functional groups presented at ends of the non-polar backbone, with a number of the functional groups presented at the ends of the non-polar backbone formed by associative functional groups capable of undergoing an associative interaction with another associative functional group with an association constant (k) such that the strength of each associative interaction is less than the strength of a covalent bond between atoms and in particular less than the strength of a covalent bond between backbone atoms.

The invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.

The use of at one or more additives to reduce the filter blocking tendency of a fuel composition having a tendency to block filters, wherein the fuel composition comprises a renewable diesel component and a biodiesel component; and wherein the one or more additives are selected from (a) a copolymer comprising units of formula (I):

##STR00001## and units of formula (II):

##STR00002##

wherein R is an alkyl group and each of R.sup.1 and R.sup.2 is an alkyl or alkenyl group having 6 to 22 carbon atoms; (b) the reaction product of a polycarboxylic acid having at least one tertiary amino group and a primary or secondary amine; and (c) the reaction product of secondary amines and a copolymer of maleic anhydride and an -olefin.

A fuel composition including renewable diesel and one or more low temperature enhancing additives selected from (a) a copolymer comprising units of formula (I):

##STR00001##

and units of formula (II):

##STR00002##

In which the R is an alkyl group and each of R.sup.1 and R.sup.2 is an alkyl or alkenyl group having 6 to 22 carbon atoms; (b) the reaction product of a polycarboxylic acid having at least one tertiary amino group and a primary or secondary amine; and (c) the reaction product of secondary amines and a copolymer of maleic anhydride and an -olefin.

Disclosed is a gas hydrate inhibitor composition comprising an amphiphile by a linking moiety, the amphiphile having of the general formula (1)
[R.sup.5-L-N(R.sup.1)(R.sup.2)(R.sup.3)].sup.+X.sup.(1) wherein each of R.sup.1 and R.sup.2 is an alkyl group having from 1 to 5 carbon atoms; or wherein the nitrogen atom and the R.sup.1 and R.sup.2 groups together form a heterocyclic group; R.sup.3 is present or not as hydrogen or an alkyl group having from 1 to 8 carbon atoms L is a linking moiety comprising a hydrocarbyl group having at least 2 adjacent carbon atoms, at least one heteroatom selected from nitrogen and oxygen, R.sup.5 is a hydrocarbyl group having from 6 to 22 carbon atoms; and X is present as an anion when R.sup.3 is present; and a cationic surfactant which is selected from quaternary benzyl ammonium salts and a method of using the gas hydrate inhibitor composition.

Processes for stabilizing toluenediamine residues are disclosed. These processes include adding a low viscosity, low boiling liquid to a toluenediamine residue composition to form a blend, and optionally, continuously monitoring the viscosity of the blend during addition of the low viscosity, low boiling liquid. The low viscosity, low boiling liquid may be added at 5% to 30% by weight based on the total weight of the blend. Further, the low viscosity, low boiling liquid may be added so that the blend has a viscosity of 10,000 cP or less throughout the temperature range of 40 C. to 95 C. Blends of toluenediamine residue compositions and low viscosity, low boiling liquids such as water, and methods of their use as a fuel are also disclosed.

The invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.