Coalbed methane separation problem
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At normal pressure, coalbed methane contains about 55% methane, 8% oxygen, and 37% nitrogen. My fellow sailors, how can we concentrate the methane in this gas to 95%? Any various physical separation methods can be used. Deoxygenation can also be carried out first, followed by physical separation. It’s best to explain the process
I only know that it can be done using oxygen-selective membranes, and the CH4/O2 selectivity is also high; the problem is that the mixture passing through the membrane falls within the explosive range. This post was last edited by yjqin1 on 2008-12-20 15:30.]
Pressure swing adsorption – currently, my separation factor can reach 3
If it preferentially adsorbs oxygen, then the desorption also falls within the explosive range.
First, the oxygen content is reduced to around 0.5%, after which pressure is increased to use pressure swing adsorption for methane concentration.
First, a nitrogen-enriched membrane is used to remove part of the oxygen; during this enrichment process, methane is also concentrated. After the permeate gas enters the organic vapor membrane for methane enrichment, two-stage membranes can be used to control the concentration, while two stages of membranes can also be employed to regulate the recovery rate
I support the view from the 6th floor; that’s what I want to say as well.
Everyone, after talking for so long, not a single person has considered the issue of explosion resulting from the concentration of oxygen in a certain airflow. Otherwise, there are many mature and available technologies such as cryogenic distillation, adsorption, oxygen-selective membrane separation, and methane (+oxygen) selective membrane separation.
I am also keeping an eye on information in that area. I’ve heard that there are two methods, though they haven’t been verified – they’re just suggestions: 1. Use a water ring compressor for compression, followed by cooling and dehydration, then use cryogenic separation to isolate nitrogen and oxygen, thereby obtaining liquefied coalbed methane; 2. Use a water ring compressor for compression, followed by cooling and dehydration, and then use PSA technology to concentrate methane. Personally, I think the first one is more reliable! I’ve only heard about it; I’ve never seen it. I hope I’ll get the chance to learn it too!
We’ve also received a similar request that requires a plan, and I find it a bit difficult. Does anyone have any successful experience in this regard?
I still focus on the issue of cost-performance, that is, suitability.