Is methanation still needed for CO removal?
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Is methanation still needed to remove CO now? Is more liquid nitrogen washing needed?
Currently, the wet method for removing carbon monoxide is both more common and more mature. However, for some plants with a low processing capacity, the methanation method should still be useful, after all, the process flow is simple.
Old industrial enterprises have been using the dimethyl process (methanol, methane), which is still quite appropriate.
I have been involved in several gasification projects, and the approaches used varied. First is the setup of the conversion unit: you need to determine to what level you want to reduce CO. If further reduction isn’t possible through conversion, methanation can be used, or the gas can be sent directly to a methanol washing unit followed by PSA, or there are other options as well.
If low-temperature methanol washing is used for purification, liquid nitrogen washing can be employed to make rational use of the cooling capacity. For other processes such as solution absorption using NHD in a medium at room temperature, the methanation process can be considered, as it is simple and requires less investment. However, the methanation process has an impact on subsequent processes. In the case of ammonia synthesis, since methane is an inert gas, it must be removed from the synthesis system; otherwise it will accumulate, leading to an increase in specific consumption.
First, the scale of the device needs to be considered; for smaller devices, the dimethyl process is recommended, while for larger devices, liquid nitrogen washing is used
How does the dual-methane process compare to PSA?
I’m not sure if you have any requirements regarding the gas pressure after CO removal Also, how can CO be utilized after PSA removal?