Adjustment of the methanol production process using coke oven gas
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I would like to ask my friends: what is the lowest temperature that can be achieved for the steam-coke mixture at the inlet of the pure oxygen converter? Currently, it is 400 degrees Celsius. Is there any risk associated with this temperature? In order to save fuel gas, is it possible to lower it further? What is the lowest possible value for the steam-to-char ratio? Our total carbon is 0.3, and the steam-to-coke ratio is currently 0.7; however, the CO2 level in the converted gas as analyzed remains relatively high. What is the lowest value that the pyroxylation ratio can be reduced to? Our current value is 5.0.
The total carbon content is 30%, which indicates that methane levels in the coke oven gas are very low. A methane-to-oxoxygen ratio as low as 5.0 indicates that the amount of water vapor is too high; the consequence is that a large amount of oxygen is added, but the temperature rise in the second furnace is not significant. The carbon dioxide content in the converted gas is related not only to the temperature at the outlet of the second-stage furnace but also to the water vapor ratio. The lower the temperature control for steaming and charring, the greater the amount of oxygen supplied. As long as the two-stage furnace does not go out and the steaming temperature remains low, there should be no major problems. However, from a safety perspective, it should not be set too low; if the heat generated by the combustion of coke oven gas and oxygen is not sufficient to raise the temperature of the gas to its ignition point, the flame will go out. Personal opinion.
Thank you to the friend above for their valuable suggestions. I hope to obtain the operating data from colleagues using other devices – what are the values for various parameters in your conversion furnaces? Share it so everyone can communicate with each other.
Reply to 5# pdslht, dear friend, are you keeping it at 0.6? What is the total carbon?
Hehe, we haven’t driven yet
Our carbonization ratio is 0.37, and the carbon monoxide-to-oxygen ratio is 5.3–5.5 (this is adjusted primarily based on the methane content in the coke oven gas). The composition at the outlet is as follows: CO: 19%, CO2: 8.5%.
This post was last edited by hg2xhj on 2011-12-7 at 18:27. I have just issued another notice to keep the CO2 level in the converted gas between 7.5 and 8.5, and to adjust the amount of steam based on the analysis results. It’s not certain whether the steam flow meter is accurate and reliable; it can only be adjusted through analysis, and it is hoped that carbon buildup will not occur.
Can using the carbon dioxide level in the gas as an indicator to control the amount of water vapor added cause regulatory lag? Tests are not necessarily done at regular intervals. The carbon dioxide content is also related to the furnace temperature. If the steam flow meter is inaccurate, it can be calibrated using analytical methods, as long as your gas flow meter is accurate. With such a low total carbon content in your gas, carbon deposition generally does not occur. Regarding the process in the second reactor, it is necessary to take into account the oxygen entering the second-stage furnace; as a result of combustion, two volumes of water are produced, which increases the water-to-carbon ratio. Just my opinion.