Alternating current of methanol conversion rate in syngas synthesis
Thread Content
1. Looking at the process technologies of Lurgi, ICI, and Topsoe, the simple conversion rate of CO is above 50%, but why do many people say it is around 20–30%, with some even indicating a rate of less than 10%? What is the reason for such a large difference? I searched on the forum, and most values are below 40%. Could someone provide a detailed explanation? 2. I conducted a simple simulation and found that at 200 degrees Celsius and with a mass of 80 kilograms, the conversion rate for synthesizing methanol from syngas (CO:H2=1:2) is over 95%. Why is this rate so low on an industrial scale? By how much exactly is it lower? Is it due to the heat transfer issues with the reactor and catalyst? I hope everyone will communicate more.
This is due to reversible reactions; generally, the one-way conversion rate is only 3-6%.
What was said upstairs is right! Our conversion rate is the same here too! I think it has something to do with both the composition of the gas and the catalyst. As for the specific reaction mechanism, I’m afraid my knowledge is limited, so I can’t explain it!
The main reason is that this reaction is reversible; additionally, in actual industrial production, the composition of the synthetic feed gas is more complex than in theoretical models, with a higher content of inert components. (To increase the overall yield, it is necessary to increase the circulation rate when the single-pass conversion rate is low, which leads to an accumulation of inert gases.) Various components have different effects on catalyst activity, thereby reducing the conversion rate； At the same time, the presence of other components reduces the CO concentration, which also leads to a decrease in its conversion rate. Exactly how much lower it is varies depending on factors such as the design and manufacturing process, the production capacity of the equipment, the production load, the type of catalyst, the temperature of the synthesis reaction, the pressure of the synthesis reaction, the composition of the feed gas, and the stage of catalyst usage.
What is mentioned on the second floor refers to the percentage of methanol at the outlet of the synthesis tower, while the original poster is talking about the conversion rate of CO. Here, the percentage of methanol at the outlet of our synthesis tower is a little over 7%, while the conversion rate of CO is above 60%. We use Lurgi equipment. What was said above makes sense – it’s a reversible reaction, and the rates at which various components adsorb onto the catalyst surface differ. I don’t really understand the rest!!!!!!!!!
Two concepts are being confused here: the alcohol content at the outlet and the one-way conversion rate (synthesis rate). In low-pressure single-column synthesis, the alcohol content using domestically produced catalysts is generally less than 8%, while imported catalysts can achieve around 8%; in medium-pressure synthesis, this value is slightly higher but does not exceed 10%. In the case of medium-pressure synthesis with two columns in series, the alcohol content at the outlet, as given by patent holders, is typically between 15% and 17%. It is said that around 15% can be achieved. The one-way conversion rates vary considerably among different plants. Based on total carbon, the conversion rate for (CO+CO2) in a single tower is generally around 20%–50%, while in a system with two towers in series it is usually above 70%, often ranging from 75% to 80%.
The conversion rate is highly dependent on the gas composition and synthesis pressure; generally, the one-way CO conversion rate is 50–60%, with a total conversion rate of over 90%. The CO2 conversion rate is 10–20%, while the total conversion rate in this case is 60–70%
It seems that my simulations and research results are fairly accurate; thank you to the friends above for their support.
It’s actually a very simple question: if the pressure is 80 kilograms and the conversion rate is 90%, then what should be the pressure at the outlet of the synthesis tower?
How is the total conversion rate of CO and CO2 calculated?
By changing the composition at the inlet of the synthesis tower to the values of fresh gas and entering them, it can be calculated.