Gas to Wire With Carbon Capture & Storage: A Sustainable Way for On-Site Power Generation by Produced Gas

Abstract

Abstract Natural gas has the potential to play an important role as a "bridge" fuel in the transition from fossil fuels towards a cleaner energy mix and a low-carbon future, due to its better environmental credentials (lower emissions of CO2 and other pollutants per MWh) and higher efficiency in power generation, compared to oil and coal. Natural gas is also suitable as a back-up fuel for complying with renewables and could turn in to a "final destination" fuel if Carbon Capture & Storage (CCS) technology would be competitive and conveniently located. Natural gas with CCS could be a cheap and reliable low-carbon energy source in the long term and a critical technology for climate change mitigation, while delivering sustainable power. Currently, the destination of most of the transported gas is as fuel for power generation, but the electricity can be generated anywhere, even at or near the reservoir source. Gas-to-Wire (GtW) is the process of generating electricity from natural gas at or in proximity of the field, a different approach than producing electricity at a centralized power plant. In the Gas-to-Wire process a gas motor (usually a gas turbine) is placed close to the field and the gas is directly converted into electricity for own use or for sale to the local market (eventually transported by cables to the destination). For a more sustainable process, the CO2 produced by the power plant could be captured and injected underground (in a water layer or a depleted reservoir, if available in the area). Thus, the costs for CO2 transport and storage are reduced and NIMBY (Not In My Back Yard) reactions are limited, as everything remains confined inside the field and the only output is electricity. Following this approach, the paper reports the results of a pre-feasibility study carried out applying the integrated GtW-CCS scheme to a gas production field. Economic sensitivities were performed determining the Levelized Cost Of Electricity (LCOE) and the CO2 captured cost as a function of: gas flow rate, power transmission distance and feedstock valorization. Our analysis evidenced that the GtW-CCS scheme can be competitive in some circumstances, for instance: in remote assets (for own power), when associated gas is present and when wire transmission lines are located nearby the field. LCOE increases when capture plant is present and is particularly sensitive to location and feedstock cost.