The gas entering an MDEA treating unit contains 0.5 mol% H2S and 8 mol% CO2. Inlet flow rate is 120 MMscfd (3.22 × 106 Nm3/d). The treater uses 50 wt% MDEA solution and has an inlet pressure of 1,000...

The gas entering an MDEA treating unit contains 0.5 mol% H2S and 8 mol% CO2. Inlet flow rate is 120 MMscfd (3.22 × 106 Nm3/d). The treater uses 50 wt% MDEA solution and has an inlet pressure of 1,000 psig (70 barg). The plant dehydrates the gas and then sells it as pipeline-quality gas. The pipeline specification requires that the gas contain no more than 0.25 grains/100 scf (6 mg/Nm3 ) of H2S and a maximum of 2% mol CO2. a. Assuming that the rich MDEA holds 0.4 mol of acid gas/mol of MDEA and the lean amine contains essentially no H2S and 0.005 mol of CO2/mol amine, what is the minimum amine circulation required (gpm [m3/h] at 60°F (15°C)) to obtain pipeline-quality gas? b. How much sulfur (LTD (tonnes/d)) would be produced from the acid gas leaving the treater, assuming 99.95% sulfur recovery? (See Chapter 16 for a discussion of sulfur recovery.)