Extraction of ethane from natural gas at high pressure by adsorption on Na-ETS-10

摘要

Methane/ethane separation was achieved using Na-ETS-10 as a packed-bed adsorbent over a pressure range of 450-5600. kPa at 298. K. At these pressures, pure methane gas raffinate streams were obtained prior to ethane breakthrough. The extract phase obtained following desorption from the packed-bed column was enriched in ethane. Extract phases containing up to 75% ethane were achieved following separations of a 93/7 methane/ethane feed mixture. Separation performance did not deteriorate as adsorption column pressures increased. Selective adsorption of a synthetic natural gas mixture using an Na-ETS-10 packed-bed column resulted in hydrocarbon outlet compositions ranging from pure methane (up to ~60 bed volumes at standard temperature and pressure) to ~93% methane, ~5% ethane and ~2% propane (~150 to ~850 bed volumes at standard temperature and pressure). In all cases, following desorption, the extract phase was highly enriched in the larger and more valuable hydrocarbons.