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 might become an energy carrier for transport applications. Manufacture via steam-reforming of natural gas is a low-cost option for hydrogen production. This study deals with the feasibility of combining the production of hydrogen from natural gas with CO₂ removal. When hydrogen is produced from natural gas, a concentrated stream of CO₂ is generated as a by-product. If manufacture is carried out near a depleted natural gas held, the separated CO₂ can be compressed and injected into the held and securely sequestered there. The incremental cost of the produced 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 recovery as a result of reservoir repressurization. Though the extra natural gas is somewhat contaminated with CO₂, it is a suitable feedstock for hydrogen production. Taking credit for enhanced natural gas recovery reduces the penalty for sequestration to a net incremental cost of typically 2%. These cost penalties are much lower than those typical of CO₂ removal schemes associated with electricity production. Attention is required for optimum plant siting in order to keep CO₂ transport costs low.