Abstract
The growing worldwide interest in low carbon electric generation technologies has renewed interest in natural gas because it is considered a cleaner burning and more flexible alternative to other fossil fuels. Recent shale gas developments have increased natural gas production and availability while lowering cost, allowing a shift to natural gas for electricity production to be a cost-effective option.
Natural gas generation in the U.S. electricity sector has grown substantially in recent years (over 31 percent in 2012, up from 17 percent in 1990), while carbon dioxide (CO2) emissions of the sector have generally declined. Natural gas-fired electrical generation offers several advantages over other fossil (e. g. coal, oil) fuel-fired generation. The combination of the lower carbon-to-hydrogen ratio in natural gas (compared to other fossil fuels) and the higher efficiency of natural gas combined cycle (NGCC) power plants (using two thermodynamic cycles) than traditional fossil-fueled electric power generation (using a single cycle) results in less CO2 emissions per unit of electricity produced. Furthermore, natural gas combustion results in considerably fewer emissions of air pollutants such as nitrogen oxides (NOx), sulfur dioxide (SO2), and particulate matter (PM). Natural gas is not the main option for deep de-carbonization. If deep reduction is prioritized, whether of the electricity sector or of the entire economy, there are four primary technologies that would be assumed to play a prominent role: energy efficiency equipment, nuclear power, renewable energy, and carbon capture and storage (CCS). However, natural gas with low carbon generation technologies can be considered a “bridge” to transition to these deep decarbonization options. This paper discusses the economics and environmental impacts, focusing on greenhouse gas (GHG) emissions, associated with alternative electricity production options using natural gas as the fuel source. We also explore pairing NGCC with carbon capture, explicitly examining the costs and emissions of amine absorption, cryogenic carbon capture, carbonate fuel cells, and oxy-combustion.
Exploring the role of natural gas power plants with carbon capture and storage as a bridge to a low-carbon future