Sub-quality natural gas contains nitrogen as the principal impurity. This project will develop new nitrogen-selective absorbents and a pressure swing absorption (PSA) technology for the removal of this impurity from natural gas before feeding into pipelines. The adsorbent development will identify modifications to solid phase substrates to effect both physiosorption and chemisorption of nitrogen from sub-quality gas streams. Some adsorbents already developed can recover carbon dioxide along with the nitrogen. This will allow a single PSA system to simultaneously remove the two most common diluents from sub-quality natural gas. Phase I will develop and test additional adsorbents, and PSA process enhancements will be evaluated. Phase II will include long term adsorbent stability tests, commercial adsorbent synthesis process development, and pilot plant testing.
Commercial Applications and Other Benefits as described by the awardee:Over 100 trillion cubic feet (TCF) of domestic natural gas reserves are low-quality. The application of nitrogen selective PSA processes should provide a nitrogen/carbon dioxide rejection process which would change these unused resources into a supply which could match the entire nation's domestic natural gas production for up to 10 years. It should also mitigate the venting of methane into the atmosphere from industrial sources.
