Large volumes of natural gas are produced throughout the world for the purpose of heating homes, producing electricity and generating heat for a wide variety of industries. As it comes from the ground, much of the gas produced contains quantities of acid gases, notably H2S and CO2. The carbon dioxide is of little consequence for the most part, but H2S is quite toxic and virtually all of this gas must be removed before the gas can be sent to commercial pipeline.

The key parameter which concerns most users is the residual acid gas concentration leaving the bottom of the stripper. If the residual acid gas concentration, called the lean amine concentration, rises above a certain point, the H2S concentration in the sweet gas will be too high to meet pipeline specifications.

The most common method to optimize the performance of the Amine unit is to increase the stripping steam rate at the reboiler. This trades the expense of increased heat duties in both the reboiler and the condenser with the expense of increased amine circulation, which results in increased pumping costs, larger cross exchanger and trim cooler, and larger absorber.

This simulation will show the operational cost saving by increasing steam rate to reboiler and by methanol injection rate optimization for the gas pipeline.