Combining acid gas treating and amine tail gas treating

摘要

One of the challenges in designing a natural gas treatment plant is to optimise the combination of the acid gas removal (AGR) unit and the sulphur recovery unit (SRU). With some feed gases, a simple AGR would supply a lean acid gas that is costly to treat in the SRU. The following case study shows how Jacobs found the perfect fit of AGR and SRU. In the gas plant shown in Figure 1, 50 000 Nm~3/h is to be treated to remove H2S, CO2 and mercaptans. Jacobs designed the plant to operate with two different feeds, one with a high H2S content and another with half the amount of H2S. The sour gas flow rate and CO2 content are the same for both cases. By employing a recycle, a good quality stream of acid gas for the SRU could be produced, in both the high H2S and the low H2S case.