Carbon deposition problem in conversion catalysts for methanol production from natural gas
Thread Content
The carbon deposition on the catalyst is mainly caused by an insufficient water-to-carbon ratio, which leads to the occurrence of side reactions: 2CO == 2C + O2, CH4 == C + 2H2, CO + H2 == C + H2O. We refer to this as thermodynamic carbon； However, the higher alkanes in natural gas tend to crack and release carbon at temperatures between 400–500 degrees Celsius. Why is the conversion temperature set around 530 degrees? At such a temperature, don’t the higher alkanes crack into methane, which in turn would release carbon as well? My question is: do these carbon release processes occur simultaneously? Is it possible for them to happen at the same time? Is there still selection? ? Will these carbons be reduced by passing steam through it? This counterknowledge is quite ambiguous; please, experts, provide a detailed explanation
Is it true that the new policy no longer allows the use of natural gas to produce methanol?
1. Increasing the temperature of the feed gas can raise the methane conversion rate. Based on experience, at the same conversion rate, increasing the inlet gas temperature by 5°C can correspondingly reduce the tube wall temperature by 2°C, which is beneficial for improving the conversion rate and protecting the conversion tubes. 2. For natural gas, when the temperature is below 660°C, the carbon removal rate is greater than the carbon deposition rate, so it is impossible for carbon to form; whereas when the temperature exceeds 660°C, the carbon deposition rate becomes greater than the carbon removal rate, and as a result carbon will deposit. The conversion inlet temperature is also 530.