Non-carcinogenic asphalts and asphalt blending stocks
AssigneeMobil Oil Corporation
InventorsGary R. Blackburn, Carl R. Mackerer, Timothy A. Roy
Life of this patent
Estimating the term…
Abstract
Non-carcinogenic asphalts and asphalt blending stocks are produced from reduced hydrocarbon feedstocks. Such non-carcinogenic products are produced by establishing a functional relationship between mutagenicity index and a physical property correlative of hydrocarbon type for the asphalt or asphalt blending stock and determining a critical physical property level which, when achieved, results in a product having a mutagenicity index of less than about 1.0. Process conditions are established so that a product stream achieving the desired physical property level can be produced. Non-carcinogenic asphalts and asphalt blending stocks are then processed utilizing the conditions so established.
Claims16
A process for the production of a substantially non-carcinogenic asphalt blending stock from a reduced hydrocarbon crude feedstock, comprising the steps of:
- (a) establishing a functional relationship by regression between mutagenicity index and an asphalt blending stock physical property indicative of mutagenicity for an asphalt blending stock process stream;
- (b) determining from said relationship a critical physical property level which, when achieved, an asphalt blending stock having a mutagenicity index of less than about 1.0 results, said critical property being the physical property which yields a value of mutagenicity index equal to 1.0;
- (c) setting process conditions to produce an asphalt blending stock achieving said critical physical property level;
- and
- (d) producing an asphalt blending stock, said deasphalted oil producing step comprising:
- (i) passing the reduced feedstock into a vacuum distillation column wherein the feedstock is separated into at least one product of distillation and a vacuum residuum byproduct;
- and
- (ii) passing at least a fraction of said residuum byproduct through a selective solvent deasphalting unit to produce a deasphalted raffinate and an asphaltenic extract, wherein said asphalt blending stock is substantially non-carcinogenic having a mutagenicity index of less than about 1.0.
A non-carcinogenic asphalt blending stock produced from a vacuum residuum said asphalt blending stock characterized by a substantial absence of carcinogenic polynuclear aromatic compounds of 3 to 7 rings in structure, said asphalt blending stock having a mutagenicity index of less than about 1.0.
A method for producing a substantially non-carcinogenic asphalt composition, the composition produced by blending a plurality of substantially non-carcinogenic asphalt blending stocks, each of the blending stocks produced by a process comprising the steps of:
- (a) establishing a functional relationship by regression between mutagenicity index and an asphalt blending stock physical property indicative of mutagenicity for an asphalt blending stock process stream;
- (b) determining from said relationship a critical physical property level which, when achieved, an asphalt blending stock having a mutagenicity index of less than about 1.0 results, said critical property being the physical property which yields a value of mutagenicity index equal to 1.0;
- (c) setting process conditions to produce an asphalt blending stock achieving said critical physical property level;
- and
- (d) producing an asphalt blending stock, said deasphalted oil producing step comprising:
- (i) passing the reduced feedstock into a vacuum distillation column wherein the feedstock is separated into at least one product of distillation and a vacuum residuum byproduct;
- and
- (ii) passing at least a fraction of said residuum byproduct through a selective solvent deasphalting unit to produce a deasphalted raffinate and an asphaltenic extract, wherein said asphalt blending stock is substantially non-carcinogenic having a mutagenicity index of less than about 1.0.
Dependencies are inferred from the claim text.