There is disclosed an antifoam component which includes at least one poly(acrylate) copolymer for use in a fuel. Poly(acrylate) polymers prepared by polymerizing a (meth)acrylate monomer comprising C.sub.1 to C.sub.30 alkyl esters of (meth)acrylic acid (“multifunctional monomer”) are also disclosed. Other poly(acrylate) polymers prepared by polymerizing (i) a (meth)acrylate monomer comprising C.sub.1to C.sub.4 alkyl esters of (meth)acrylic acid (“solubility monomer”); (ii) a (meth)acrylate monomer comprising C.sub.5 to C.sub.12 alkyl esters of (meth)acrylic acid (“surface tension monomer”); and (iii) optionally at least one additional monomer comprising a solubility monomer, a surface tension monomer, a monomer comprising C.sub.1 to C.sub.30 alkyl esters of (meth)acrylic acid (“multifunctional monomer”), or combinations thereof are also disclosed.

A biodiesel composition comprising a stabilization agent is disclosed. The stabilization agent comprises depolymerized lignin having a weight average molecular weight of at least 360 g/mol and at most 5000 g/mol, and the TEAC value of the depolymerized lignin is at most 50% of the TEAC value of a corresponding lignin before having been depolymerized, and wherein the weight average molecular weight of the depolymerized lignin is at most 60% of the weight average molecular weight of the corresponding lignin.

A biodiesel composition comprising a stabilization agent is disclosed. The stabilization agent comprises depolymerized lignin having a weight average molecular weight of at least 360 g/mol and at most 5000 g/mol, and the TEAC value of the depolymerized lignin is at most 50% of the TEAC value of a corresponding lignin before having been depolymerized, and wherein the weight average molecular weight of the depolymerized lignin is at most 60% of the weight average molecular weight of the corresponding lignin.

Method for reducing the pollutant emissions of internal combustion engines, wherein an aqueous solution containing glyoxal and a polymer product of citric acid and glycerol is added as an additive, additive for reducing the pollutant emissions of internal combustion engines, said additive consisting of an aqueous solution containing glyoxal and a polymer product of citric acid and glycerol, and the use thereof for reducing pollutant emissions.

A method of treating petroleum fluids may include adding a flow improver composition to the petroleum fluids, the flow improver composition, comprising: a solvent; and a dendrimer-based flow improver, wherein at least a portion of the surface sites of the dendrimer are chemically modified with saturated and unsaturated fatty acids.

A method of treating petroleum fluids may include adding a flow improver composition to the petroleum fluids, the flow improver composition, comprising: a solvent; and a dendrimer-based flow improver, wherein at least a portion of the surface sites of the dendrimer are chemically modified with saturated and unsaturated fatty acids.

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.

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.

A fuel formulation having a derived cetane number of at least 35 includes a petroleum fraction and a polyoxymethylene dimethyl ether (OMEx) oligomer mix. The petroleum fraction includes a naphtha fraction with a boiling point in the range from 30° C. to 178° C. The polyoxymethylene dimethyl ether oligomer mix has the general formula H.sub.3CO—(CH.sub.2O).sub.n—CH.sub.3 in which n is between 2 and 7, inclusive. A related method for reducing emissions in a compression-ignited engine includes preparing the fuel formulation having a derived cetane number of at least 35 and combusting the fuel formulation in the compression-ignited engine in place of a diesel fuel, thereby reducing emission of at least one of NOx, CO.sub.2, or particulates from the compression-ignited engine.

A fuel formulation having a derived cetane number of at least 35 includes a petroleum fraction and a polyoxymethylene dimethyl ether (OMEx) oligomer mix. The petroleum fraction includes a naphtha fraction with a boiling point in the range from 30° C. to 178° C. The polyoxymethylene dimethyl ether oligomer mix has the general formula H.sub.3CO—(CH.sub.2O).sub.n—CH.sub.3 in which n is between 2 and 7, inclusive. A related method for reducing emissions in a compression-ignited engine includes preparing the fuel formulation having a derived cetane number of at least 35 and combusting the fuel formulation in the compression-ignited engine in place of a diesel fuel, thereby reducing emission of at least one of NOx, CO.sub.2, or particulates from the compression-ignited engine.