RECOVERY OF HYDROGEN FROM FRACTIONATION ZONE OFFGAS

摘要

Methods and apparatus for increasing the recovery of hydrogen from fractionation section offgas are described. The methods include reducing the pressure of a liquid effluent from a high-pressure reaction zone, and introducing the effluent into a flash drum forming a low pressure liquid effluent. The low pressure effluent is introduced into a low-pressure stripper column, and separated into an overhead vapor stream and at least one additional stream. The stripper column overhead vapor stream is compressed in a one cylinder of a compressor, which has at least one additional cylinder, to an intermediate pressure. The compressed overhead stream is introduced to an intermediate pressure knockout drum forming a gas stream and a liquid stream. The gas stream is introduced into a pressure swing adsorption zone to produce a hydrogen rich gas stream at an intermediate pressure.

主权项

1. A method of increasing the recovery of hydrogen from fractionation section off-gas comprising:
reducing a pressure of a liquid effluent from a high-pressure reaction zone; introducing the reduced pressure effluent into a flash drum to form a low pressure liquid effluent and a flash gas stream; introducing the low pressure liquid effluent into a low-pressure stripper column; separating the low pressure liquid effluent into an overhead vapor stream and at least one additional stream in the stripper column; compressing the stripper column overhead vapor stream in a first cylinder of a compressor to an intermediate pressure, the compressor having at least one additional cylinder; introducing the compressed overhead vapor stream to an intermediate pressure knockout drum to form a gas stream and a liquid stream; introducing the gas stream from the intermediate pressure knockout drum into a pressure swing adsorption zone to produce a hydrogen rich gas stream at an intermediate pressure.