Patent ID: 7427350
Filing Date: 2008-09-23
Classification: B01D

Abstract:
1. A refinery process comprising a delayed coking operation further comprising reducing foaming of a coker feedstock susceptible to foaming comprising adding to the coker feedstock before and/or during the delayed coking operation an effective amount of a composition comprising polydimethylsiloxane (PDMS) crosslinked with a crosslinker selected from the group consisting of siloxane and alkyl polysilicate to reduce foaming, where less crosslinked PDMS is necessary to achieve the same foam reduction compared to a linear PDMS, where the effective amount of the total amount of polydimethylsiloxanes is in a ratio of from about 0.1 ppm to about 250 ppm based on the coker feedstock to be defoamed, and where the temperature of the coker feedstock ranges from about 350° F. (177° C.) to about 1000° F. (538° C.).