THE ELEPHANT IN THE ROOM: DEALING WITH CARBON EMISSIONS FROM SYNTHETIC TRANSPORTATION FUELS PRODUCTION

摘要

There has been considerable interest in producing synthetic transportation fuels via coal-to-liquids (CTL) hydrocarbon conversion, particularly in countries where there is an abundant domestic coal resource. In the United States, there is currently a public policy debate over the use of coal to produce liquid transportation fuels to increase energy security and decrease dependence on imported petroleum and refined products. There are a number of challenges to be faced by a possible CTL industry, and one of the largest relates to the magnitude of carbon dioxide (CO2) generated, from the synthetic fuel production as well as from the combustion of the synthetic transportation fuel itself. Co2, produced by conversion of hydrocarbons to energy, primarily via fossil fuel combustion, is one of the most ubiquitous and significant greenhouse gases (GHGs). Concerns over climate change precipitated by rising atmospheric GHG concentrations have prompted many industrialized nations to begin adopting limits on emissions to inhibit increases in atmospheric CO2 levels. The United Nations Framework Convention on Climate Change states as a key goal the stabilization of atmospheric GHGs at a level that prevents “dangerous anthropogenic interference” with the world's climate systems. This will require sharply reducing CO2 emissions across the globe and ultimately a fundamental shift in the way in which energy is produced and consumed. This paper provides an overview of the challenge posed by the magnitude of CO2 that would be produced from a developing CTL industry. The status and costs associated with carbon dioxide capture and geologic storage (CCS) technologies are discussed as a means of helping to mitigate the CO2 issue, along with remaining challenges that must be overcome for an emerging CTL industry to move toward maturity. However, even if CCS can be safely and successfully applied to CTL plants, CO2 emissions will still likely be greater than conventional liquid transportation fuel production from conventional petroleum.