Questions about methanol production
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Is there oxygen at the conversion outlet of the coke oven gas to methanol system? Our company is facing this issue right now: the oxygen content in the exported gas ranges from 0.2 to 0.3, while the oxygen content in the synthesized gas reaches 0.9. Yet, the temperature of the synthesis tower bed remains stable, just as it usually is. We would appreciate guidance from relevant experts – what could be causing this? Thank you in advance!
Check the issue analyzed; the oxygen content is so high that the catalyst gets oxidized
Reply to 2# lulifenga: I posted this because no issues could be found through laboratory analysis, that’s why I’m seeking help from everyone
Reply to 3#: The exit temperature of the converter is 920–930, but there is oxygen present at the converter outlet. I’m not sure what the reason for this is; please advise.
There are three reasons for the presence of oxygen at the converter gas outlet: first, the oxygen-to-coke ratio at the converter inlet is high, resulting in incomplete reaction, though this possibility is very low； Second, the temperature of the conversion furnace is set too low, resulting in incomplete reaction ； Third, the converter design is unreasonable; the gas residence time is too short, preventing the reaction from reaching equilibrium. The high oxygen content in the syngas is due to cumulative cycling, and the vent volume can be increased appropriately. It would also be useful to check recent changes in the composition of coke oven gas, to see if there are any fluctuations in the levels of hydrogen and methane ； Or check whether there are any abnormalities in the method of sample collection; insufficient replacement during sampling may lead to air contamination.
With a high oxygen content in the system, it’s normal for the temperature of the synthesis tower bed to rise above the normal level. Pay attention to the operating pressure of the steam drum