Gasification combined cycle: Carbon dioxide recovery, transport, and disposal

Abstract

Initiatives to limit carbon dioxide (COz) emissions have drawn considerable interest to integrated gasification combined-cycle (IGCC) power generation. This process can reduce CO 2production because of its higher efficiency, and it is amenable to CO/ capture, because CO 2 can be removed before combustion and the associated dilution with atmospheric nitrogen. This paper presents a process-design baseline that encompasses the IGCC system, CO 2 transport by pipeline, and land-based sequestering of CO 2 in geological reservoirs. The intent of this study is to provide the CO 2 budget, or an "equivalent CO2" budget, associated with each of the individual energy-cycle steps. Design capital and operating costs for the process are included in the full study but are not reported in the present paper. The value used for the "equivalent CO2" budget will be 1 kg CO2/kWh e. The base case is a 470-MW (at the busbar) IGCC system using an air-blown Kellogg Rust Westinghouse (KRW) agglomerating fluidized bed gasifier, U.S. Illinois #6 bituminous coal feed, and in-bed sulfur removal. Mining, feed preparation, and conversion result in a net electric power production of 461 MW, with a 0.830 kg/kWh e CO 2 release rate. In the CO 2 recovery case, the gasifier output is taken through water-gas shift and then to Selexol, a glycol-based absorber-stripper process that recovers CO 2 before it enters the combustion turbine. This process results in 350 MW at the busbar. A 500-km pipeline takes the recovered CO 2 to geological sequestering. The net electric power production in the recovery case is 320 MW, with a 0.234 kg/k_Vh e CO 2 release rate.

Comparative life cycle environmental assessment of CCS technologies

“…Life cycle assessment (LCA) is a well-established method and best suited for such analysis. Few environmental assessments have been published with primary focus being on coal with post-combustion and/or pre-combustion capture (Benetto et al, 2004;Doctor et al, 1993;Khoo and Tan, 2006;Koornneef et al, 2008;Korre et al, 2009;Rao and Rubin, 2002). Few studies have also considered natural gas CCS options (Audus and Freund, 1997;Hertwich et al, 2008;Odeh and Cockerill, 2008;Singh et al, 2010;Summerfield et al, 1995;Waku et al, 1995;Lombardi, 2003).…”

Life cycle assessment of natural gas combined cycle power plant with post-combustion carbon capture, transport and storage

“…An overview of the scope of existing LCA studies on electricity generation systems with CCS is presented in Table 1. Doctor et al (1993), Summerfield et al (1995), Waku et al (1995) and Audus and Freund (1997) made some early assessments of different CCS configurations based on mass and energy balance. Waku et al reported the emission control potential for liquefied natural gas combined cycle power plant and integrated coal gasifier combined cycle power plant (IGCC) in the range of 61-69% and 65-76%, respectively.…”

Illustrative national scale scenarios of environmental and human health impacts of Carbon Capture and Storage

“…Previous studies have demonstrated that life-cycle assessment (LCA) is a powerful tool to define the emissions associated with individual CCS plants and other energy systems (Doctor et al, 1993;Koornneef et al, 2008;Odeh and Cockerill, 2008c;Pehnt and Henkel, 2009;Sathre et al, 2012;Spath and Mann, 2004;Viebahn et al, 2007). Tzimas et al (2007) provided insight regarding potential trade-offs between increased emissions of acid pollutants and decreased CO 2 emissions when CCS is implemented, suggesting that NO X emissions might be amplified across the power generation sector.…”