Applications in Landfill Gas Energy Recovery

Prosser et al. discussed on the performance and economics of carbon molecular sieve membranes in landfill gas energy recovery apphcations [6]. 

CMSMs look promising for landfill gas (LFG) processing since they may enhance the BTU values of LFGs. Shallow landfills, landfills located in arid environments, or the landfills sites that extract landfill gas higher than it is generated in order to protect the environment are excellent candidates for this technology. Removal of CO2 gas from the LFG will restore the methane quality to an acceptable level for fuel. It is estimated that this process could benefit 5-15% of all landfills 

US Filter mesoporous tubular substrates were used as the support to study the membrane feasibility in laboratory scale. Polyetherimide (PEI) was used as the polymeric precursor. The support substrate (7 mm ID, 10 mm OD) was dip coated in PEI solution followed by drying in air and caibonization in an argon atmosphere. 

LFG from the interior of a landfill may not require CO2 removal. In this case the value added will be to utilize perimeter gas or poor qu ty interior gas that may otherwise be flared. In arid climates, LFG collected even in the interior part of a landfill may not be suitable for use in engines. The value added in this case is to treat the entire gas stream to a level acceptable to the engines. 

Upgrading the LFG to the level suitable for injection to the natural gas pipeline is another applicatioa With the aid of CMSMs this application may be economical even for small scale (1-5 million tons of MSW) landfills. No modification is necessary for the equipment at the end user. The application requires relatively expensive treatment of LFG and also, in order to inject into the natural gas pipeline, there are strict specifications that impose additional quality control and compression requirements. 

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