Sulfur-tolerant shift process for preparing methyl methanol syngas

Abstract

The invention provides a CO sulfur tolerant shift method for preparing methanol synthesis gas. The method at least comprises the following two stages of shift: crude gas is pretreated and is heated up to 180 to 260 DEG C, the gas enters a first reactor for the shift reaction when a water to gas volume ratio is 0.1 to 0.55, the bed temperature is 330 to 420 DEG C, and the CO volume content is 36 to 48 percent after the first shift reaction; and the gas from the first reactor is cooled down to 200 to 280 DEG C through heat exchange and water spray, the gas enters a second reactor for the shift reaction when a water to gas volume ratio is 0.1 to 0.75, the bed temperature is 390 to 450 DEG C, and the dry basis CO volume content in the final outputted gas is 8 to 35 percent. A CO sulfur tolerant shift catalyst is used during the two stages of shift. The outputted gas at the second stage can be directly used or for preparing the methanol synthesis gas or be used for preparing the methanol synthesis gas after a third stage of deep shift gas distribution. The method has the advantages of low water to gas ratio, energy conservation, low equipment cost, wide raw material sources, and the like.

Description

technical field [0001] The present invention relates to a sulfur-resistant conversion process for producing methanol synthesis gas from high-concentration CO raw material gas, in particular to a sulfur-resistant conversion process for producing methanol synthesis gas from high-concentration CO raw material gas in two or more stages using coal as raw material craft. Background technique [0002] Methanol is an important basic chemical raw material, which can be used to produce various organic products such as formaldehyde, acetic acid, and dimethyl terephthalate. Methanol is also an important solvent and is widely used in the production of pesticides, medicines, spices and the three major synthetic materials. Especially after the 1980s, due to the environmental protection policy of "unleaded gasoline" promoted by industrialized countries in the world, the unleaded gasoline additive MTBE using methanol as raw material has been developed and widely used, becoming the second la...

AI Technical Summary

Problems solved by technology

[0005] In the prior art, the water / gas ratio in the CO shift process is relatively large. For the shift of high-concentration CO raw material gas, because the CO concentration and water / gas are both high, the driving force of the reaction is large, and the catalyst loading in the first stage only needs a small change. , it will significantly affect the hot spot temperature of the bed, so the amount of catalyst must be accurate, otherwise it will cause the bad result of "flying temperature" of the bed due to the increase of reaction depth

Practice has proved that in the initial stage of start-up of some factories, due to the low load or the large catalyst filling margin, the first reactor has overheated phenomenon. It causes a waste of energy, and because the first stage of the catalyst operates under the harsh conditions of high water / gas and high temperature, the catalyst is replaced frequently, which affects normal production

For plants with low sulfur content in raw gas, there will also be anti-sulfurization due to high temperature and high water / gas, so high-sulfur coal must be selected or sulfur added or CS injected 2 To increase the sulfur content in the process gas, in order to maintain normal production, which limits the selection range of raw coal