Refinery off-gas is rich in ethylene and ethane, meanwhile it also contains some other alkene and alkane such as propylene, propane, and butylene. Earlier, refinery off-gas is mainly burned as fuel gas of low value. If alkene and alkane could be sent to ethylene unit as feedstock to produce ethylene after being recovered from refinery off-gas, big quantity of pyrolysis raw oil will be saved and the cost of ethylene production will be reduced significantly. The technology of refinery off-gas recovery by shallow cold oil absorption developed by SINOPEC could be used to recover C2+ with remarkable economic benefit.
(1) Higher recovery of C2;
(2) Good feedstock adaptability: various refinery off-gas could be used;
(3) No specific requirement for the content of H2S;
(4) The produced C2 rich gas is free of NOx and CO, and oxygen content is less than 1 ppm, while methane less than 5%;
(5) Simple configuration, easy operation, long operation cycle;
(6) Small plant size, low investment, low energy consumption.