Simulation of the natural gas purification process with membrane technology. Technical and economic aspects

Abstract

The economy of the sweetening process of natural gas with membrane technology was analyzed in this study based on an own synthesized polyimide membrane. ProII commercial software was utilized to simulate the process with three different configurations: a) single stage, b) double stage with permeate recycle and c) triple stage with retentate recycle, using CH4/CO2/H2S as a ternary mixture with different compositions. The economic analysis was made taking the single stage configuration as a reference in relation to multiple step configurations. Gas processing cost (GPC) is mainly affected by three parameters: total plant investment (TPI), annual variable operating and maintenance costs (VOM) and annual cost of methane lost in the permeate (CH4LS). These three parameters behave in opposite trends as feed pressure and feed flow increase.