Regulation of gas composition in fluidized bed furnaces
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How can a fluidized bed furnace increase methane production? Please ask an expert for advice :) This post was last edited by Tianya Langji on 2009-1-14 09:43.]
Ugh, to increase the methane content, why use a fluidized bed? Just use an upper fixed bed, right?
Our fluidized bed boilers use gas generation slag as fuel, while the boilers that burn methane are triple-gas waste heat boilers. Increasing methane means reducing the cycle time in the hydrogen production section (both vent gas and tank gas are sent to pressure swing adsorption for hydrogen production), thereby raising the concentration of the recovered hydrogen.
You guys are probably working with fuel gas, and the aim of increasing methane content is to raise the calorific value, right? Please answer
Methane production is an exothermic reaction that results in a decrease in volume. Could we consider adjusting the temperature? Lowering the reaction temperature has little effect on pressure, and this aspect is rarely considered. In all the cases I’ve seen, the method used to reduce methane content is by increasing the furnace temperature
Lowering the reaction temperature affects the intensity of the reaction
Here’s a suggestion: it’s important to choose the right coal feeding point; when the coal feeding point is located in the reduction zone, the methane concentration in the gas increases.
Methane reaches its highest level at around 650 degrees. Of course, a fluidized bed cannot operate at such a temperature. If the temperature cannot be changed, the only option is to increase the pressure. However, pressure generally cannot be increased in a fluidized bed; therefore, the only solution is to adjust the residence time. If the residence time is too short, tar will form. In that case, the only option is to adjust the ratio of coal quality to water and oxygen. The optimal ratio still needs to be determined through practical experimentation – everything is interrelated
The temperature should increase a bit when it drops. To achieve a high methane content in syngas, a fixed-bed reactor is still the best choice.