How to calculate the amine solution circulation volume
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1. May I ask, if the exhaust volume and composition are known, how can the required amount of amine solution circulation be calculated? For example, if the volume of exhaust gas (on a dry basis) is 10,000 Nm3/H, with a H2S concentration of 2% and a CO2 concentration of 5%, what is the circulation rate required for an MDEA amine solution with a concentration of 30%? 1. May I ask, how should the effective payload of the amine solution be understood?
First, determine the acid gas load of the solution based on empirical values (approximately 0.1 mol of hydrogen sulfide and carbon dioxide per mol of amine), and then assume that 40% of the carbon dioxide in the exhaust gas is absorbed together. The volume of exhaust gas (on a dry basis) is 10,000 Nm3/h; the H2S concentration is 2%, and the CO2 concentration is 5%. The total amount of acidic gases removed per hour is approximately 16.7 kmol. For 30% concentrated MDEA solution, this amount is about 2.52 kmol. Therefore, the flow rate of the solution required for circulation is approximately 66 cubic meters per hour.
In practice, this is mainly calculated based on the liquid leakage line of the tower or the spraying rate of the packing, etc.; from a process perspective, the hydrogen sulfide content in the amine-enriched solution derived from sulfur exhaust gases generally does not exceed 5 g/L. The acid gas ratio of the amine solution is moles of hydrogen sulfide per mole of amine.
Should the acid gas load be taken as 0.1? It’s so small; my system is overloaded here. Is the 0.1 experience value set by the designers or by the solvent manufacturer?
Both the actual operating level and the design level are this value