Overall low-temperature shift process water-to-gas ratio
Thread Content
In the shift unit of coal-to-methanol production, if a full low-temperature shift process is used, what should be the water-to-gas ratio (H2O/dry gas) at the inlet of the shift reactor?
I’ve looked up some information, but there are different opinions. In the book \"Engineering of Ammonia Synthesis,\" a value of 3–4 is given for H2O/CO. On forums, some people say that the value for H2O/dry gas is around 1.5, while others claim it’s below 1.0. I also downloaded the instructions for using a sulfur-resistant shift catalyst, which states that the value for H2O/dry gas is approximately 0.5. So, experts, what is the correct value?
The book \"Methanol Production Technology\" states that the vapor-to-gas ratio in the full low-temperature shift process is around 0.2
How can it be all low variation? Methanol requires a certain hydrogen-to-carbon ratio. We use low-temperature conversion: [inlet 265, outlet 441, inlet water vapor ratio 1.158]
The inlet value is over 0.2 (determined based on the catalyst’s activity); the overall gas-to-vapor ratio is 0.5 (including the amount of cooling effect)
By water vapor ratio of 1.158, do you mean H2O/CO=1.158, or H2O/dry gas=1.158? Just as the friend upstairs said it’s only 0.2-0.5, what ratio is he referring to?
Are you referring to H2O/dry gas? But for an inlet ratio of 0.2, the CO content in the raw water gas is generally around 45%. If the water-to-gas ratio is only 0.2, there is a severe shortage of H2O for the shift reaction; wouldn’t this hinder the progress of the forward reaction? The conversion rate will be relatively low.
Steam is better than gas; it depends on the CO content in the gas – the designed CO level is 30%, with an inlet steam-to-gas ratio of around 0.25. The manufacturer specializing in low-temperature conversion processes will provide you with the relevant data; they have the necessary calculations, and you can use those figures to make adjustments