If the MEA unit in Exercise 10.1 is converted to 50 wt% MDEA, what is the annual savings in operating expense? Assume an MEA flow rate of 686 gpm (156 m3/h). Rich MDEA can hold 0.45 mol of acid gas...

If the MEA unit in Exercise 10.1 is converted to 50 wt% MDEA, what is the annual savings in operating expense? Assume an MEA flow rate of 686 gpm (156 m3/h). Rich MDEA can hold 0.45 mol of acid gas per mole of amine and the lean amine has essentially zero acid gas. Use properties from Table 10.3 and Appendix B. Ignore amine losses and pumping cost. Fuel gas costs $3.00/MMBtu and the furnace is 80% efficient.

Exercise 10.1

Feed gas enters an amine treating unit at a rate of 100 MMscfd (2.68 × 106 Nm3/d). The gas contains 5% CO2 and no H2S. The treater uses 18 wt% MEA solution. Assume the lean amine contains 0.12 mol CO2/mol of amine and the rich amine contains 0.45 mol CO2/mol amine. To meet the pipeline specification of 2% CO2, what minimum lean amine flow rate in gpm (m3/h)