Recovery of propane and heavier components from various refinery offgas streams and from low-pressure associated natural gas. Propane recovery levels approaching 100% are typical.
Low-pressure hydrocarbon gas is compressed and dried before being chilled by crossexchange and propane refrigerant. The chilled feed stream is then contacted with a recycled liquid ethane stream in the propane absorber. The absorber bottoms is pumped to the deethanizer, which operates at higher pressure than the absorber. The tower overhead is condensed with propane refrigerant to form a reflux stream composed primarily of ethane. A slip stream of the reflux is withdrawn and recycled back to the propane absorber. The deethanizer bottoms stream contains the valuable propane and heavier components which may be further processed as required by conventional fractionation.
Economics: Compared to other popular LPG recovery processes, PRO-MAX typically requires 10–25% less refrigeration horsepower.
Licensor: Black & Veatch Pritchard, Inc.