Impacts of benzene and piperazine concentrations on LNG plant capacity

K. K. Hwang and S. Kim, SK E&C, Houston, Texas Benzene emissions can have an effect on LNG plant capacity when a vent gas incinerator is not present. Here, a typical amine sweetening unit for acid gas removal, featuring a typical lean feed gas composition, is modeled using commercial amine sweetening software to calculate annual benzene emissions rates. The maximum allowable benzene content in a given feed gas rate is set by US Environmental Protection Agency (EPA) benzene emissions limits. Two parameters—benzene concentration in the feed gas stream and piperazine content in the methyldiethanolamine (MDEA) solution—are used to determine LNG plant capacity. LNG plant capacity is describ