Process for dedusting solids-containing hydrocarbon oils

Claim 1

A process for dedusting oils characterized as unconventional whole heavy crudes, heavy petroleum crude fractions and residua, syncrudes, syncrude fractions, and syncrude residua, which contain finely divided solids, which comprises dispersing from about 10 parts to about 5000 parts, per million parts of oil by volume, of an admixture of surfactant and demulsifier within said oil, the surfactant being (I) an ester characterized as follows: ##STR6## where R 1 , R 2 , R 3 , and R 4 are selected from (a) ethoxy or propoxy groups, or mixed ethoxy and propoxy groups, and (b) the dehydroxylated residue of a fatty acid molecule, or moiety represented by the formula ##STR7## where R is a straight-chain hydrocarbon moiety which can be substituted or unsubstituted, saturated or unsaturated, and where unsaturated can contain conjugated or unconjugated double bonds, and at least one and up to three of R 1 , R 2 , R 3 , and R 4 is ethoxy, propoxy, or mixed ethoxy and propoxy groups, the demulsifier being (II) an ethoxylated or propoxylated, or admixed ethoxylated/propoxylated, phenol formaldehyde resin substituted at a position para to the ethoxy or propoxy group, or mixed ethoxy/propoxy groups, by a hydrocarbyl group, said modified phenol formaldehyde resin being characterized as follows: ##STR8## wherein R 7 represents one or more ethoxy or propoxy groups, or mixed ethoxy and propoxy groups, R 8 is a hydrocarbyl radical selected from the group consisting of alkyl, aralkyl, cycloalkyl, aryl, alkaryl, alkenyl, and alkynyl, and m is an integer of one or greater, the molecular weight of said resin ranging from about 2000 to about 20,000; the ratio of demulsifier:surfactant ranging from about 1:1 to about 15:1, based on the sum total volume of the demulsifier and surfactant, admixing in a first stage washwater in concentration ranging from about 5 percent to about 50 percent, based on the volume of oil, with said surfactant/demulsifier-containing oil, and emulsifying same to form an oil and water emulsion, separating said oil and water emulsion into an oil phase and solids-containing water phase, recovering from said first stage an oil phase of reduced solids, admixing with said surfactant/demulsifier-containing oil in a second stage additional washwater in concentration ranging from about 5 percent to about 50 percent, based on the volume of oil, passing said admixture of surfactant/demulsifier-containing oil and water through a heat exchanger and heating said admixture to a temperature ranging from about 100° F. to about 350° F., emulsifying said heated admixture of surfactant/demulsifier-containing oil and water, passing said emulsion into an electrostatic coalescer, maintaining said emulsion at a temperature ranging from about 100° F. to about 350° F. for a period ranging from about 10 minutes to about 80 minutes, while separating said oil and water emulsion into an oil phase overflow, and solids containing water phase underflow, and recovering from said second stage an oil phase of reduced solids suitable as a feed for use in refining operations.