Methane content in semi-water gas
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Our company produces gas by using coal rods, but the composition of the gas is poor – the methane content is between 5.2% and 5.6% – which results in high amounts of gas being wasted during the synthesis process, leading to significantly insufficient output. What should be the typical methane content when producing gas with coal rods? Where is our problem? Additional note: 1. In semi-water gas, carbon dioxide accounts for 10.5%, carbon monoxide 27.0%, and hydrogen 46% ； 2. Ash content of coal rods: 23%, volatile matter: 9%
The content is generally around 1-1.5%. Coal sticks have a high volatility content, and the methane content is high when the operating temperature is too low.
I’m not sure how you determine the allocation of time for various processing steps. Given that the carbon dioxide level is 10.5%, this seems quite high; a high methane content may be due to low furnace temperatures during the later stages of gas production, which result in methanation reactions at lower temperatures. Last edited by shanxg on 2009-2-11 20:39.]
The high methane content is mainly related to the reaction temperature; if the reaction temperature is between 600–800°C, the methane content will certainly not be low, as this is determined by the equilibrium constant of the methanation reaction.
I see that your levels of CO2 and CH4 are quite high. It seems that these two concentrations are related to the temperature of the furnace; have you set the furnace temperature too low?
The problem might lie with the raw coal used; the temperature when burning coal rods is low, but your 5% value is too high
Is furnace temperature control crucial? Given such a high methane content and large production capacity, it is advisable to consider installing a small methane steam reforming system in the downstream system. :)
The methane level in our plant is around 1.4%. The CO2 and CH4 levels in your plant are quite high; it seems that the furnace temperature is not high enough. Check what the quality of the coal is like ； Samples are taken at different gas production stages to analyze the gas composition and identify the causes.
The furnace temperature is too low, which favors the exothermic methanation reaction to proceed in the direction of methane formation