Payload in MDEA
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The last edit to this post was made by liaifeng on 2018-9-10 at 19:57. When calculating the effective load before and after the purification of the MDEA solution, does the effective load before purification involve determining the levels of H2S and CO2 in the solution, and then is the effective load calculated again after purification when the effective amine is produced?
You are referring to the acid gas load. MDEA has recommended values for acid gas load in both lean and rich solvents, but this value is also affected by the MDEA concentration, selectivity, and operating conditions; it is recommended to use software for calculations
MDEA acid gas load (normal range) ①: 0.022–0.056. Acid gas load (normal range) ②: 0.2–0.55 (mol/mol of amine). Residual acid gas load in the lean solution (normal range) ③: 0.005–0.01 (mol/mol of amine). Acid gas load in the rich solution (normal range) ②: 0.4–0.55 (mol/tml of amine). Solution mass concentration (normal range): 40–50%. ① Depends on the acid gas partial pressure and solution concentration. ② It depends on the acid gas partial pressure and the corrosivity of the solution; for corrosive systems, it is only 60% or lower. ③ It varies with the reflux ratio at the top of the regeneration tower; a lower residual acid gas load in the lean liquid requires more trays or a higher reflux ratio in the regeneration tower. And it increases the heat load on the reboiler. The method of expressing the acid gas load (mainly H2S and CO2) is only accurate for the conventional alcohol-amine process, which performs both desulfurization and decarbonization simultaneously. For the alcohol-amine process designed for selective H2S removal, it is meaningful to use the H2S load, as CO2 needs to be kept away from its equilibrium load.