gascleanup

Gas cleanup, also referred to as gas treating or gas purification, is the set of processes used to remove contaminants from gas streams to meet product specifications, protect equipment, and reduce environmental impact. It is commonly applied to natural gas, refinery gases, syngas, and other process gases in chemical plants.

Common contaminants include water vapor, hydrogen sulfide (H2S), carbon dioxide (CO2), mercaptans, heavier hydrocarbons, particulates, and trace metals. In natural gas, H2S and CO2 cause corrosion and formation of acid gases, while water promotes hydrates and pipeline corrosion. Removing these components helps prevent corrosion, catalyst poisoning, odor issues, and pipeline or equipment damage, and it can also enable subsequent processing steps.

Major technologies used in gas cleanup include acid gas removal using amine treaters (such as MEA, MDEA, or DEA) to remove H2S and CO2; dehydration methods (glycol dehydration or solid desiccants) to lower water content; sweetening to reduce sulfur compounds; filtration and particulates removal; mercury removal with activated carbon or other sorbents; adsorption processes (PSA, temperature swing adsorption) and membrane separation; and sometimes cryogenic or other selective separation techniques for specific streams.

Applications span natural gas processing, refinery offgas cleanup, coal gasification syngas cleanup, and other industrial gas streams. The goals are to ensure product quality, protect pipelines and equipment, meet environmental and safety regulations, and minimize emissions and corrosion. Considerations include energy use, solvent degradation and losses, sorbent management, and overall process integration to control operating costs.