The sustainability of clean coal technology: IGCC with/without CCS

Abstract Integrated gasification combined cycle power generation (IGCC) is one of the emerging clean coal technologies for reducing greenhouse emissions in coal-fired electricity generation. IGCC technology, both with and without CO2 capture and storage (CCS) is compared with conventional super-critical power generation based on pulverized coal. The comparison is based on an equal consumption rate of Queensland black coal. The sustainability parameters being investigated are: thermal efficiency, environmental performance, inherent safety and economics. The IGCC processes have been modeled using commercial steady-state mass and energy balance software. Both the gross and net thermal efficiencies of the IGCC power station are reduced when the plant is configured for CCS. The net efficiency is reduced from 32.1% to 26.1%, when 81% of the CO2 is captured. This delivers an overall reduction in CO2 emissions per unit of electrical energy output of 73.2% compared to the reference plant. However, environmental performance in other areas suffers as a result of switching to IGCC-CCS, particularly fresh water consumption is increased by 2.5 tonne/MWh for both coastal and inland locations. Inherent safety risks associated with IGCC are also greater with the gasifier being the highest risk unit in the facility with a Dow fire and explosion index of 168 compared with an index of 107 for a conventional boiler. Toxicity hazard also increases with carbon monoxide present at concentrations several thousand times higher than the TWA limit. The minimum viable selling price of electricity for a 7% IRR is calculated to increase from USD80 MWh−1 for a conventional power station to USD101 MWh−1 for IGCC and to USD145 MWh−1 for IGCC-CCS. It is concluded that the application of IGCC-CCS is highly effective in reducing carbon dioxide emissions, the highest-profile problem associated with coal-fired electricity. There is an economic penalty which has been previously documented. However, there are also drawbacks concerning inherent safety and other environmental factors apart from CO2 emissions, which until now have been under emphasized.

[1]  Reginald B. H. Tan,et al.  Selection of inherently safer process routes: a case study , 2004 .

[2]  Rainer Reimert,et al.  Gas production from coal, wood and other solid feedstocks , 2000 .

[3]  John M. Campbell,et al.  Gas conditioning and processing , 1970 .

[4]  D. R. Simbeck,et al.  Process screening study of alternative gas treating and sulfur removal systems for IGCC (Integrated Gasification Combined Cycle) power plant applications: Final report , 1987 .

[5]  Anna-Mari Heikkilä,et al.  Inherent safety in process plant design : an index-based approach , 1999 .

[6]  Shahid Abbas Abbasi,et al.  Multivariate hazard identification and ranking system , 1998 .

[7]  W. Adams.  The Future of Sustainability: Re-thinking Environment and Development in the Twenty-first Century , 2006 .

[8]  Z. Fonyó,et al.  SYNTHESIS OF HEAT EXCHANGER NETWORKS , 1982 .

[9]  Chorng H. Twu,et al.  A new generalized alpha function for a cubic equation of state Part 1. Peng-Robinson equation , 1995 .

[10]  John R. Flower,et al.  Synthesis of heat exchanger networks: I. Systematic generation of energy optimal networks , 1978 .

[11]  Edward S. Rubin,et al.  Cost and performance of fossil fuel power plants with CO2 capture and storage , 2007 .

[12]  B. Metz.  IPCC special report on carbon dioxide capture and storage , 2005 .

[13]  N. Stern.  The Economics of Climate Change: Implications of Climate Change for Development , 2007 .

[14]  Bernd Meyer,et al.  Carbon Capture and Storage Power Plants : Effects of ASU Integration on IGCC Performance and Gas Turbine Operation , 2008 .

[15]  H. J. Hurst,et al.  Ash and slag qualities of Australian bituminous coals for use in slagging gasifiers , 2000 .

[16]  Faisal Khan,et al.  Integrated inherent safety index (I2SI): A tool for inherent safety evaluation , 2004 .

[17]  J. Ross.  Ullman's encyclopedia of industrial chemistry , 1986 .

[18]  K. Jordal,et al.  Gas conditioning—The interface between CO2 capture and transport , 2007 .

[19]  Eric Croiset,et al.  Technoeconomic evaluation of IGCC power plants for CO2 avoidance , 2006 .

[20]  Howard J. Herzog,et al.  Carbon Dioxide Capture and Storage , 2009 .

[21]  Klaus D. Timmerhaus,et al.  Plant design and economics for chemical engineers , 1958 .

[22]  R. Keiski,et al.  Water-gas shift reaction on a cobalt-molybdenum oxide catalyst , 1993 .

[23]  Cameron Hepburn,et al.  The Economics and Politics of Climate Change , 2009 .