GB801917A - Transfer line chemicals coking process - Google Patents

Abstract

<PICT:0801917/III/1> Heavy hydrocarbon oils boiling above 900 DEG F. are converted to lighter hydrocarbon products and coke by contacting them with a dispersed suspension of particulate solids at a coking temperature in the range of 1200-1600 DEG F. in a transfer line reaction zone by first mixing the oils in an amount of 0.1 to 0.4 lb. per pound with flowing particulate solids recovered from the transfer line effluent to form a dense phase suspension in a riser, the temperature of the resulting admixture being from 50-500 DEG F. below said coking temperature, and thereafter adding freshly heated solids having a temperature above 1300 DEG F. to raise the temperature of the mixture to said coking temperature, and passing the heated mixture as a dispersed suspension through said transfer line reaction zone. The starting material may be reduced crudes, vacuum bottoms, pitch or asphalt, such feeds having an initial boiling point above 700 DEG F., an API gravity of 0 to 20 degrees and a Conradson carbon residue of 5-40 weight per cent. In a preferred embodiment a heavy viscous residual oil feed is injected into a transfer line reactor 10 by premixing it with relatively cooler flowing solids in a riser 22. Solids at a temperature 100-400 DEG F. higher than the desired coking temperature are fed through a line 21 and are admixed with the feed and cooler particles before passing into the transfer line 10. A cyclone 11 separates out the solids which pass to a stripper 12. The conversion products are removed overhead through line 14 and a quench medium which may be water, light oil or cooled coke particles, enters by line 15.ALSO:<PICT:0801917/IV (b)/1> Heavy hydrocarbon oils boiling above 900 DEG F. are converted to lighter hydrocarbon products such as ethylene, propylene, and butadiene and coke by contacting them with a dispersed suspension of particulate solids at a coking temperature in the range of 1200-1600 DEG F. in a transfer line reaction zone by first mixing the oils in an amount of 0.1 to 0.4 lbs. per pound with flowing particulate solids recovered from the transfer line effluent to form a dense phase suspension in a riser, the temperature of the resulting admixture being from 50-500 DEG F. below said coking temperature, and thereafter adding freshly heated solids having a temperature above 1300 DEG F. to raise the temperature of the mixture to said coking temperature, and passing the heated mixture as a dispersed suspension through said transfer line reaction zone. The starting material may be reduced crudes, vacuum bottoms, pitch or asphalt, such feeds having an initial boiling point above 700 DEG F., an A.P.I. gravity of 0 DEG to 20 DEG and a Conradson carbon residue of 5-40 weight per cent. In a preferred embodiment a heavy viscous residual oil feed is injected into a transfer line reactor 10 by premixing it with relatively cooler flowing solids in a riser 22. Solids at a temperature 100-400 DEG F. higher than the desired coking temperature are fed through a line 21 and are admixed with the feed and cooler particles before passing into the transfer line 10. A cyclone 11 separates out the solids which pass to a stripper 12. The conversion products are removed overhead through line 14 and a quench medium which may be water, light oil or cooled coke particles, enters by line 15.