Discussion on the purification of water-gas shift gas

Thread Content

Discussion on the purification of water-gas shift gas: Taking the low-temperature methanol washing purification process in Shenhua Baotou as an example, purifying the shift gas at 40°C, 5.6 Mpa, and 17,574 Kmol/h yields four products: a purified gas at 40°C, 5.6 Mpa, and 12,206 Kmol/h (with temperature and pressure remaining constant)； Carbon dioxide at 40°C, 0.25 Mpa, and 1547 Kmol/h (with temperature held constant) ； Flue gas at 40°C, 0.105 Mpa, and 3731 Kmol/h (considering only carbon dioxide, with temperature held constant) ； Acidic gas at 40°C, 0.2 Mpa, and 104 Kmol/h. Process 1: The 3 types of products to be obtained are now to be converted back into synthesis gas: Carbon dioxide is compressed to increase its pressure, with compression being completed in one step; this requires 20525787 KJ/h and 5701 KW of power, while heat is released at a rate of 49603446 KJ/h and 7623176 kcal/h. The exhaust gas is compressed to increase its pressure, with compression being completed in one step; this requires 71902965 KJ/h and 19973 KW of power, while 117579706 KJ/h or 28083430 kcal/h of heat is released. Acidic gas compression raises pressure; compression is completed in one step. It requires 1507887 KJ/h and 418 KW of power, while releasing 2375284 KJ/h and 567327 kcal/h of heat. Total: Power consumption 26,092 KW, heat release to the outside 36,273,933 Kcal/h – maximum value! Process 2: Assuming Process 1 is reversible, the gas purification process can perform work of 26,092 KW on the outside environment, and release heat (provide cooling) at a rate of 36,273,933 Kcal/h. Question: How to proceed with step 2? ——I have been working on purification-related tasks. Although some clarity has emerged regarding the issues mentioned above, I truly hope for your involvement and guidance! Cui Jingsi