Perspectives on CCS Cost and Economics

Kheshgi, Haroon S. (ExxonMobil Research and Engineering Company) | Thomann, Hans (ExxonMobil Research and Engineering Company) | Bhore, Nazeer A. (Exxon Mobil Corporation) | Hirsch, Robert B. (ExxonMobil Gas and Power Marketing Company) | Parker, Michael E. (ExxonMobil Production Company) | Teletzke, Gary (ExxonMobil Upstream Research Company)



Focus on carbon capture and storage (CCS) has grown over the past decade with recognition of CCS's potential to make deep CO2-emission reductions and that fossil fuels will continue to be needed to supply much of the world's energy demands for decades to come. How CCS will compare with other options in the future depends critically on the cost of CCS (the focus of this paper) and resolution of barriers to CCS deployment and costs and barriers for other emission-reduction options.

This paper provides a comparison of the cost of electricity of five power-generation options--coal-and-gas-combined cycle gas turbine (CCGT) with and without CCS and nuclear--and shows regions of carbon price and fuel prices where each can be economically viable.

Current cost estimates for coal CCS for nth-of-a-kind power-generation plant are in the USD 60 to 100/t of CO2 avoided, which is higher than some of the earlier CCS estimates, and higher than the generally accepted range of expected carbon prices in the next 2 decades. The high cost of coal CCS suggests that

  • Gas-based power generation is significantly more economical than coal CCS at carbon prices less than USD 60 to 100/t CO2.
  • Even after carbon prices reach USD 60 to 100/t CO2, gas CCS produces lower-cost electricity than coal CCS, as long as natural-gas prices remain less than USD 9/1,000 Btu.
  • Nuclear has a lower cost of electricity than coal CCS.

Although coal or gas CCS is unlikely to be economical in power generation over the next 2 decades, subsidized demonstrations of CCS are likely to occur. In addition, components of CCS technologies will continue to be economically practiced in early-use segments [e.g., natural-gas processing and enhanced-oil-recovery (EOR) operations]. In the natural-gas-processing industry, CO2 separation cost is a fraction of the cost of CO2 capture in power generation because of its higher gas pressure, and the CO2 separation is typically necessary to monetize the natural-gas resource.

In contrast, CCS for most refinery and industrial emissions is expected to be significantly more costly than in power generation because the CO2 streams are typically smaller scale and more distributed than those from large power plants.

Realistic cost estimates for CCS and for other greenhouse-gas (GHG) mitigation options are an important input for focusing research, development, and demonstration addressing barriers to applications that show the greatest promise and for development of sound policy.