Calculations regarding desulfurization and purification

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I’m unsure whether the calculations for dry desulfurization purification are correct; I would appreciate some guidance from experts. Assumed gas composition: flow rate of 2,880 cubic meters per hour (under standard conditions); impurities include 70 milligrams of H2S per cubic meter, and organic sulfur, measured as COS, amounts to 40 milligrams per cubic meter. The desulfurization process chosen is: preliminary removal using iron oxide at 0.2 MPa, followed by hydrolytic desulfurization at 0.6 MPa, and then further removal using iron oxide at 0.6 MPa. Parameters for the desulfurizing agents: the dynamic sulfur capacity of iron oxide is 20% (by mass), with a density of 0.7 kg/L; the efficiency of the hydrolytic desulfurizing agent is greater than 99%, with a density of 0.8 kg/L. The optimal space velocity is set between 500 and 1,000 hours per cubic meter (based on parameters provided by domestic manufacturers). The required total sulfur content in the output gas is 0.1 PPM. Calculation process: all calculations are based on 8,000 hours of operation. 1. Total amount of hydrogen sulfide: a.) 70 * 2,880 * 8,000; b.) COS + 2H2O → 2H2S + CO2 + 32.66 KJ/mol. Therefore, a + b = 2,534 kg. Amount of iron oxide desulfurizing agent needed: 2,534 / 1,000 = 18.1 cubic meters. 2. Amount of hydrolytic catalyst needed: Since the activity conversion parameters of the catalyst are unknown, the space velocity used in the first stage of desulfurization is taken as a reference for calculation. Based on the above calculations, with a total amount of iron oxide of 18.1 cubic meters, the first stage uses approximately 9 cubic meters of iron oxide. Assuming a porosity of 50% as provided by the manufacturer, the space velocity in the first stage is 2,880 / 4.5 = 640 hours per cubic meter. After the first compression step, the pressure in the hydrolysis section rises to 0.6 MPa, so the space velocity in the hydrolysis tower becomes 640 * 3 = 1,920 hours per cubic meter. Thus, the amount of hydrolytic catalyst needed is 2,880 / 1,920 = 1.5 cubic meters. However, the optimal space velocity suggested by the manufacturer is between 500 and 1,000 hours per cubic meter; therefore, this value should be adjusted to 1,000. Hence, the previously calculated value of 1.5 cubic meters should actually be 2.88 cubic meters. The rounded value for the volume is 3 cubic units: 18.1 cubic units of iron oxide (rounded up to 20 cubic units), of which 10 cubic units are used for primary rough desulfurization, 3 cubic units for hydrolytic desulfurization agents, and 10 cubic units for advanced desulfurization. I would appreciate your guidance on whether the above calculations are correct. Thank you very much. Give beginners a chance to learn and improve.