摘要 |
It has been discovered that crosslinked polydimethylsiloxane (PDMS) resins are useful defoamers and antifoamers for hydrocarbon-containing liquids, such as delayed coker feedstocks and feedstocks to preflash and atmospheric towers. These PDMS resins are crosslinked with either alkyl polysilicate or siloxane. The crosslinked PDMS resins may be used alone or together with linear PDMS, and are typically blended with a carrier such as kerosene for easier handling. Importantly, the use of crosslinked branched PDMS resins permit less total amount of polysiloxanes to be used, which reduces the silicon carryover in coker products and reduces poisoning of downstream catalysts. |