Troubleshoot and solve a gas treater downcomer unsealing problem: Part 2

摘要

The ADGAS Integrated Gas Development (IGD) fuel gas treatment (FGT) system is a methyldiethanolamine (MDEA) absorber-regenerator system designed to supply 25 MMscfd of sweet fuel gas (having less than 20 ppm of H2S) for the IGD turbines and the flare purge and pilots. The FGT system was designed by an engineering contractor from Japan, and the tower internals were provided by a major tray supplier. At plant rates above 10 MMscfd-12 MMscfd, the absorber column, which contained moving valve trays, became very unstable and flooded, resulting in a sudden liquid carryover that led to tripping the whole system. Changes to the MDEA flowrates did not appear to have much influence. Any attempt to raise the gas load above 10 MMscfd-12 MMscfd and keep stable column operation failed. An attempt to fix the problem by the contractor and vendor failed to provide a significant improvement.