# US 7,465,395 B2 · Methods and compositions for removing residues and substances from substrates using environmentally friendly solvents > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,465,395 B2 - Document ID: US7465395B2 - Status: Granted - Kind: B2 - Application number: 11/634,754 - Filed: 2006-12-06 - Published: 2007-05-03 - Granted: 2008-12-16 - Earliest claimed: 2002-02-27 - Assignees: North Carolina State University - Inventors: Ruben G. Carbonell; Peter Kilpatrick; Nael Saki - Web page: https://patentgrep.com/patent/US7465395B2 ## CPC - C08L 95/00: Compositions of bituminous materials, e.g. asphalt, tar, pitch - B01D 11/0288: {Applications, solvents} - C10C 3/007: {winning and separation of asphalt from mixtures with aggregates, fillers and other products, e.g. winning from natural asphalt and regeneration of waste asphalt} - C10C 3/08: by selective extraction - C10G 1/04: by extraction - C10G 21/003: {Solvent de-asphalting} - C10G 21/08: Inorganic compounds only - C10G 21/16: Oxygen-containing compounds - C10G 29/22: containing oxygen as the only hetero atom - C11D 7/5022: {containing oxygen} - C10G 2300/206: Asphaltenes - C10G 2300/301: Boiling range - C10G 2300/44: Solvents - C11D 7/266: {Esters or carbonates} - C11D 2111/48: Regeneration of cleaning solutions - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - C10C: WORKING-UP PITCH, ASPHALT, BITUMEN, TAR; PYROLIGNEOUS ACID (compositions of bituminous materials C08L95/00; carbon filaments by decomposition of organic filaments D01F9/14) - C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES - C11D: DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL ## Abstract Environmentally friendly solvents used to dissolve or remove residues and/or substances from substrates wherein the residue and/or substance is contacted with a Generally Recognized As Safe solvent to dissolve the residue and/or substance in the solvent followed by the extraction of the residue and/or substance from the solvent such as by contact with carbon dioxide. ## Claims ### Claim 1 A method of dissolving a petroleum-based substance, comprising: introducing the petroleum-based substance to a reaction vessel, the petroleum substance comprising one or more of asphalt, asphaltenes and bitumen; contacting the petroleum-based substance with a benzoic acid ester-containing solvent introduced to the reaction vessel, the solvent being miscible with carbon dioxide and having a flash point greater than about 98° C.; dissolving at least a portion of the petroleum-based substance in the benzoic acid ester-containing solvent contacting the petroleum-based substance; removing a product from the reaction vessel, wherein the product comprises at least a portion of the petroleum-based substance dissolved in at least a portion of the solvent; and contacting the product with carbon dioxide such that the petroleum-based substance is precipitated from the product. ### Claim 2 (depends on 1) The method of claim 1, wherein the benzoic acid ester-containing solvent is a GRAS (Generally Recognized As Safe) solvent. ### Claim 3 (depends on 1) The method according to claim 1, wherein the petroleum residue comprises bitumen. ### Claim 4 (depends on 1) The method according to claim 1, wherein the liquid benzoic acid ester-containing solvent is selected from the group consisting of methyl benzoic ester, ethyl benzoic acid ester, n-propyl benzoic acid ester, isobutyl benzoic acid ester, n-butyl benzoic acid ester, tert-butyl benzoic acid ester, isopropyl benzoic acid ester, isomers of pentylbenzoate, and mixtures thereof. ### Claim 5 (depends on 1) The method according to claim 1, wherein the benzoic acid ester-containing solvent comprises at least about 95 percent by weight of benzoic acid ester. ### Claim 6 (depends on 1) The method according to claim 1, wherein the carbon dioxide comprises at least one of liquid carbon dioxide, gaseous carbon dioxide, and supercritical carbon dioxide. ### Claim 7 (depends on 1) The method according to claim 1, wherein the petroleum-based substance is present as an asphalt residue. ### Claim 8 (depends on 1) The method according to claim 1, wherein the petroleum-based substance has a boiling point greater than about 150° C. ### Claim 9 (depends on 1) The method according to claim 1, wherein the petroleum-based substance comprises asphaltene, and wherein said contacting step comprises removing from about 60 to 100 percent by weight of asphaltene based on the asphaltene present in the petroleum-based substance. ### Claim 10 (depends on 1) The method according to claim 1, wherein the petroleum-based substance comprises bitumen and inorganic material, and wherein the inorganic material remains subsequent to said step of contacting the petroleum-based substance sample with benzoic acid ester-containing solvent, said method further comprising contacting the inorganic material at least once with an organic solvent. ### Claim 11 A method for recovering bitumen, comprising: contacting a substance containing bitumen with a benzoic ester-containing solvent having a flash point greater than about 98° C., the solvent being miscible with carbon dioxide; dissolving at least a portion of the bitumen from the substance in the ester-containing solvent; contacting the ester-containing solvent and dissolved bitumen with carbon dioxide to precipitate bitumen from the ester-containing solvent; and recovering the precipitated bitumen. ### Claim 12 (depends on 11) The method according to claim 11, wherein the ester containing solvent is a benzoic acid ester selected from the group consisting of methyl benzoic ester, ethyl benzoic acid ester, n-propyl benzoic acid ester, isobutyl benzoic acid ester, n-butyl benzoic acid ester, tert-butyl benzoic acid ester, isopropyl benzoic acid ester, isomers of pentylbenzoate, and mixtures thereof. ### Claim 13 (depends on 12) The method according to claim 12, wherein the benzoic acid ester-containing solvent is isopropylbenzoic acid ester. ### Claim 14 (depends on 12) The method according to claim 12, wherein the benzoic acid ester-containing solvent comprises at least about 95 percent by weight of benzoic acid ester. ### Claim 15 (depends on 11) The method according to claim 11, wherein the carbon dioxide comprises at least one of liquid carbon dioxide, gaseous carbon dioxide, and supercritical carbon dioxide. ### Claim 16 (depends on 11) The method according to claim 11, wherein the substance containing bitumen has a boiling point greater than about 150° C. ### Claim 17 (depends on 11) The method according to claim 11, wherein the substance containing bitumen comprises bitumen and inorganic material, and wherein the inorganic material remains subsequent to said step of contacting the substance with benzoic acid ester containing solvent, said method further comprising contacting the inorganic material at least once with an organic solvent. ### Claim 18 A method of dissolving a petroleum-based substance, comprising: introducing the petroleum-based substance to a reaction vessel, the petroleum substance comprising one or more of asphalt, asphaltenes and bitumen; contacting the petroleum-based substance with a GRAS ester-containing solvent having a flash point greater than about 98° C. introduced to the reaction vessel, the solvent being miscible with carbon dioxide; dissolving at least a portion of the petroleum-based substance in the ester-containing solvent; withdrawing at least a portion of the ester-containing solvent and dissolved portion of the petroleum-based substance from the reaction vessel as a product; and precipitating the petroleum-based substance from the product. ### Claim 19 (depends on 18) The method of claim 18, wherein the ester-containing solvent is a liquid benzoic acid ester-containing solvent. ### Claim 20 (depends on 19) The method according to claim 19, wherein the benzoic acid ester solvent is selected from the group consisting of methyl benzoic ester, ethyl benzoic acid ester, n-propyl benzoic acid ester, isobutyl benzoic acid ester, n-butyl benzoic acid ester, tert-butyl benzoic acid ester, isopropyl benzoic acid ester, isomers of pentylbenzoate, and mixtures thereof. ### Claim 21 (depends on 19) The method according to claim 19, wherein the benzoic acid ester-containing solvent is isopropylbenzoic acid ester. ### Claim 22 (depends on 19) The method according to claim 19, wherein the benzoic acid ester-containing solvent comprises at least about 95 percent by weight of benzoic acid ester. ### Claim 23 (depends on 18) The method according to claim 18, wherein the carbon dioxide comprises a mixture of at least two selected from the group consisting of liquid carbon dioxide, supercritical carbon dioxide, and gaseous carbon dioxide. ### Claim 24 (depends on 18) The method according to claim 18, wherein the petroleum-based substance is present as an asphalt residue and has a boiling point greater than about 150° C. ### Claim 25 (depends on 18) The method according to claim 18, wherein the petroleum-based substance comprises asphaltene, and wherein said contacting step comprises removing from about 60 to 100 percent by weight of asphaltene based on the asphaltene present in the petroleum-based substance. ### Claim 26 (depends on 18) The method according to claim 18, wherein the petroleum-based substance comprises bitumen and inorganic material, and wherein the inorganic material remains subsequent to said step of contacting the petroleum residue sample with benzoic acid ester containing solvent, said method further comprising contacting the inorganic material at least once with an organic solvent. ### Claim 27 A method of dissolving a petroleum-based substance, comprising: introducing the petroleum-based substance to a reaction vessel, the petroleum substance comprising one or more of asphalt, asphaltenes and bitumen; contacting the petroleum-based substance with isopropyl benzoic acid ester (IPB) introduced to the reaction vessel; dissolving at least a portion of the petroleum-based substance in the IPB contacting the petroleum-based substance; removing a product from the reaction vessel, wherein the product comprises at least a portion of the petroleum-based substance dissolved in at least a portion of the IPB; and contacting the product with carbon dioxide such that the petroleum-based substance is precipitated from the product. ### Claim 28 A method for recovering solvent, comprising: contacting a substance containing a petroleum-based substance with a benzoic acid ester-containing solvent having a flash point greater than about 98° C., the solvent being miscible with carbon dioxide, the petroleum substance comprising one or more of asphalt, asphaltenes and bitumen; dissolving at least a portion of the petroleum-based substance in the benzoic acid ester-containing solvent; contacting the benzoic acid ester-containing solvent and dissolved petroleum-based substance with carbon dioxide to precipitate the petroleum-based substance from the benzoic acid ester-containing solvent; and separating the solvent and the carbon dioxide to recover the solvent.