HYDROGEN-PRODUCTION FROM NATURAL-GAS, SEQUESTRATION OF RECOVERED CO2 IN DEPLETED GAS-WELLS AND ENHANCED NATURAL-GAS RECOVERY

If fuel cells are introduced for vehicular applications, hydrogen migh t become an energy carrier for transport applications. Manufacture via steam-reforming of natural gas is a low-cost option for hydrogen prod uction. This study deals with the feasibility of combining the product ion of hydrogen from natural gas with CO2 removal. When hydrogen is pr oduced from natural gas, a concentrated stream of CO2 is generated as a by-product. If manufacture is carried out near a depleted natural ga s field, the separated CO2 can be compressed and injected into the fie ld and securely sequestered there. The incremental cost of the produce d hydrogen (for CO2 compression plus transport, injection and storage) would typically be about 7% relative to the case where the separated CO2 is vented. Moreover, CO2 injection leads to enhanced natural gas r ecovery as a result of reservoir repressurization. Though the extra na tural gas is somewhat contaminated with CO2, it is a suitable feedstoc k for hydrogen production. Taking credit for enhanced natural gas reco very reduces the penalty for sequestration to a net incremental cost o f typically 2%. These cost penalties are much lower than those typical of CO2 removal schemes associated with electricity production. Attent ion is required for optimum plant siting in order to keep CO2 transpor t costs low.