Converter water-gas ratio
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For the methanol production from coke oven gas as designed by the Second Chemical Engineering Institute, how should the water-to-gas ratio in the converter be calculated? Should everything be converted to volume first before calculation? Is the steam generated by combustion after pure oxygen enters the converter counted?
Does no one know? ? ? ? ? ? ? ?
Hello, the water-gas ratio we are talking about should refer to the proportion of steam and coke oven gas, and there is online analysis for this at the control room. We call the ratio of the volumetric flow rate of steam entering the conversion furnace to that of coke oven gas the water-to-gas ratio.
Partial oxidation of coke oven gas is also known as autothermal conversion. That is, in the combustion chamber at the upper part of the converter, part of the H2 and CH4 present in the coke oven gas react with the oxygen in the oxygen-enriched steam, releasing a large amount of heat to supply the energy required for methane conversion. The high-temperature gases from the upper part proceed to the catalyst layer at the lower part; the remaining CH4 in the coke oven gas undergoes a conversion reaction with steam under the action of a nickel-based catalyst (H2O/gas ≥ 0.9), resulting in a CH4 content of ≤0.5% in the gas exiting the converter.
The steam flow meters here are extremely inaccurate, so we’re unable to provide you with exact figures. However, for your information, the water vapor in the water-vapor ratio refers to the steam that ultimately enters the conversion furnace, that is, the sum of the steam supplied with oxygen and the steam supplied with coke.
Let S represent: S = volume flow rate of water vapor / volume flow rate of coke oven gas
The water-to-vapor ratio should be the ratio of volumetric flows, but steam flow meters generally measure mass flow; therefore, it is necessary to convert this to a volumetric flow by using the formula: volumetric flow = mass flow * 22.4. The gas flow rate also needs to be multiplied by the percentage of methane, and it is this calculation that yields the gas-to-water ratio.
The water-to-gas ratio generally refers to the ratio of the amount of steam plus oxygen*2 to the volume of coke oven gas; however, in conversion processes, the water-to-carbon ratio is usually controlled. As for the carbon in the total carbon ratio, there are different methods of calculation – some take into account only hydrocarbons, while others consider all forms of carbon
Steam volume for the converter multiplied by coke oven gas volume multiplied by 22.4 (mole count) divided by 18 (molecular weight of steam)