Coal and natural gas have and will likely continue to be key components of the world energy supply for years to come. Currently, the most efficient commercial technologies for power production are supercritical pulverized coal combustion (SCPC) and natural gas combustion with combined cycle (NGCC). Emerging technologies for more efficient power generation from coal include ultra-super-critical pulverized coal (USCPC), advanced ultra-super-critical PC, integrated gasification combined cycle (IGCC), integrated gasification fuel cell combined cycle (IGFC), and direct carbon fuel cell. They each have different capital and operating costs leading to different levelized cost of electricity (LCOE). To forecast each of these competing technologies under various scenarios of electricity demand, fuel cost, and research investment, we created a Power Technology Futures Model (PTFM) based on "learning curves" methodology. Technology learning curves are a powerful tool for forecasting anticipated performance improvements due to a broad range of technical improvements without specifying the parameters of every possible improvement. The model can help planners and policy makers explore, visualize, and communicate how research and development (R&D) investments in certain technologies affect the mix of technologies deployed in the future. We utilized the Analytica modeling package and included detailed economic calculations to estimate the levelized costs for several types of coal and natural gas power plants with and without carbon capture technologies. Future improvements in plant efficiency and reductions in capital and operating and mantainence (O&M) costs were modeled using technology learning curves that were established by a detailed analysis of historic performance data. We used published estimates of future demand and fuel costs where available, but the model allows the user to easily input other numbers as tables or equations. Adoption of carbon capture was modeled in a variety of ways including being driven by a carbon cap or a carbon tax. The results of the model depict the difficulty of meeting a 50% reduction in annual CO2 production by 2050, even with significant R&D investments, ambitious CO2 pricing, and decreased demand for energy from coal and natural gas.

Capture of carbon dioxide from an advanced integrated gasification combined-cycle (IGCC) process offers several technical and economic advantages over the conventional coal-combustion systems. The pre-combustion gas stream is at high pressure, has low volumetric flow rates and is capable of producing relatively pure hydrogen for conversion into electricity by gas turbines or fuel cells without generating additional carbon dioxide.Polybenzimidazole (PBI) polymer shows promise as a high temperature membrane material for pre-combustion-based capture of CO2 from IGCC gas streams. We are developing a process that is based on PBI membrane to achieve a capture of 90% CO2 as a high pressure stream with about 10% increase in the cost of energy. A significant advantage of the PBI membrane compared to other sorbent-based technologies and conventional polymeric membranes is that PBI membrane is capable of operating at over a broader temperature range (similar to 100-400 degrees C). In contrast, solvent-based processes such as Selexol require syngas cooling prior to treatment, followed by reheating the processed fuel gas stream.In this paper, we are presenting the preliminary results of a process simulation using the ASPEN program under several scenerios including the IGCC with no CO2 capture, IGCC with Selexol, and IGCC with PBI membrane separator. The high temperature membrane-based CO2 capture method compares favorably against the Selexol-based CO2 capture method. If H2S remains with the CO2 stream and can be sequestered, then the cost of electricity appears to be lower than Selexol-bsed separation systems. (C) 2008 Elsevier Ltd. All rights reserved