Types of Gas Processing Plants: 4 Key Systems Explained

Process Description

·Low-Temperature + Temperature Swing Adsorption (TSA) Process Description:

   After molecular sieve dehydration, the raw gas enters a plate-fin heat exchanger for precooling, causing partial condensation of C₅+ heavy hydrocarbons. It is then deeply cooled by a turbo-expander or mixed refrigerant, and oil phase (recovering LPG/NGL) is separated in a low-temperature separator. Residual heavy hydrocarbons in the gas phase enter the TSA molecular sieve adsorption tower, where heavy hydrocarbons are selectively adsorbed. The outlet gas, with heavy hydrocarbon content ≤ 20 mg/Nm³, is sent to the liquefaction unit. After adsorption saturation, heated purified gas is used for reverse purging regeneration. The desorbed heavy hydrocarbons are cooled and recovered, and the regeneration gas is used as fuel gas.

·Cryogenic Distillation for Nitrogen Removal:

   After dehydrocarbonization, the raw gas exchanges heat with top nitrogen and bottom methane in the precooling section to lower its temperature and partially remove heavy hydrocarbons. It then enters the main cooler, where it is deeply cooled to -162°C by a DMR mixed refrigerant and enters the middle of the nitrogen removal tower. The top nitrogen is fully refluxed in the condenser, while the bottom methane is vaporized in the reboiler and rises, completing distillation separation. The bottom methane is reheated to ambient temperature and exported as product gas. The top pure nitrogen gas is used as fuel gas after recovering cold energy in the expander, achieving self-balance of cold energy.

·Manufacturing, Installation, and Commissioning Period:

   Modularized for factory assembly and on-site installation, ensuring efficient product delivery. The total project duration from contract signing to successful commissioning is 7 months.