Integrated Gasification Combined Cycle Power Plant Research Articles

Energy and economic assessment of IGCC power plants integrated with DME synthesis processes

The combined production of dimethylether (DME) and electrical energy in Integrated Gasification Combined Cycle (IGCC) power plants is a very attractive option for exploiting the world's huge coal reserves achieving high efficiency and low pollutant emissions, as well as for enhancing the flexibility and economic performance of coal gasification plants. Besides being used for power generation in combined cycle plants, the clean synthesis gas produced by coal gasification processes can also be used as raw material for producing hydrogen, methanol, DME, and other chemicals. In particular, recent studies show the growing interest of DME as a new clean fuel for diesel engines, gas turbines, fuel cells, and household uses. This article concerns an energy and economic assessment of two different IGCC power plants integrated with a once-through DME synthesis process. In particular, the study has been carried out by examining two different solutions for the gasification process: one based on a dry-fed and the other on a slurry-fed entrained-flow gasifier. The energy assessment has shown that the DME production in IGCC power plants leads to a DME/coal energy conversion of ∼31—32 per cent and an electrical/coal energy conversion of ∼22—25 per cent. Overall, the solution based on the dry-fed gasifier exhibits the best exergy performance (50.8 versus 52.7 per cent). Finally, the economic analysis reveals DME production costs (6—6.5$/GJ) comparable with other premium fuels such as natural gas, liquefied petroleum gases, and so on.

Back to the future [IGCC plant

Energy contenders from 22 locations across nine US states are vying to become the host of the first-ever coal-fuelled, zero-emission power generation plant. Part of the US government's $1 billion FutureGen project, the plant will employ cutting edge integrated gasification combined cycle (IGCC) technology and will serve as a large-scale engineering laboratory for testing new clean power, carbon capture and coal-to-hydrogen technology. This futuristic IGCC plant will base its design and operation on the wealth of experience from a range of existing demonstration IGCC power plants.

Toward zero emissions from coal in China

China depends for most of its energy on coal – a situation that is likely to persist in the light of the abundance of its coal resources, the paucity of its oil and gas resources, and the reluctance of the government to allow China to become overly dependent on energy imports. The challenge is to find ways to use coal without the enormous air pollution damage caused by current conversion technologies and with greatly reduced carbon dioxide (CO 2 ) emissions. A coal energy system for China is proposed that could ultimately be characterized by near-zero emissions of both air pollutants and greenhouse gases. The key enabling technology is oxygen-blown (O 2 –blown) gasification to generate synthesis gas from coal. This technology is used in commercially ready integrated gasification combined-cycle power plants that can provide electricity with air pollutant emissions as low as emission levels for natural gas combined-cycle plants. O 2 -blown gasification is not yet used in China's energy sector, although the technology is well-established in China's chemical process industry. The key enabling strategy, which would often lead to attractive energy costs without further technological advances, is “polygeneration” – the co-production from synthesis gas of at least electricity and one or more clean synthetic fuels (e.g., dimethyl ether (DME), Fischer-Tropsch (F-T) liquids, hydrogen (H 2 )) and often also chemicals, town gas, and/or industrial process heat. The products of polygeneration could be used in the near term to serve a wide range of energy needs with extremely low levels of air pollutant emissions. In such polygeneration configurations CO 2 can often be produced in relatively pure streams as a co-product as a result of processing to increase the synthetic fuel's hydrogen-to-carbon ratio. In the near term this CO 2 might be used profitably for enhanced oil recovery or enhanced recovery of methane from deep beds of unminable coal where resource recovery opportunities exist. For the longer term the potential exists for evolving the coal energy system to the co-production primarily of electricity and H 2 for serving urban areas, with most of the carbon in the coal ending up as CO 2 that is sequestered in geological reservoirs such as in depleted oil and natural gas fields and deep saline aquifers at low incremental cost – even where there are no opportunities for using the CO 2 for enhanced resource recovery. The H 2 so produced would be used for fueling zero-polluting fuel-cell vehicles, for distributed cogeneration (combined heat and power) applications in stationary fuel cells, and for cooking and heating applications as well. A third clean carbon-based synthetic fuel might also be needed for serving rural markets that would be difficult to serve with H 2 , unless there are breakthroughs in H 2 storage technology. DME is a strong candidate for becoming the “third” clean energy carrier for China. Evolving a coal-based energy system that would be characterized ultimately by near-zero emissions of air pollutants and greenhouse gases would probably involve shifting the center of gravity for central-station power generation to the chemical process industries that would ultimately be co-producing as their major products electricity, H 2 , and (perhaps) DME. Ongoing structural reforms in the electric power sector that encourage greater competition in power generation would facilitate the realization of this vision for coal.

Performance of integrated gasification combined cycle power plants integrated with methanol synthesis processes

Base-load integrated gasification combined cycle (IGCC) power plants can perform load-following service by integration with a methanol synthesis process. The methanol, produced from a portion of the coal gas and stored in liquid phase, can be used for matching intermediate and peak-load demand. In this paper, the load modulation capabilities of IGCC power plants for the coproduction of electricity and methanol have been investigated. Referring to a conventional duty cycle, the main performance of power plants combining slurry-feed entrained-bed gasification and gas or liquid phase methanol synthesis has been assessed, for two different peaking electric power generation solutions. Moreover, the flexibility of these plants has been evaluated for different operating conditions, some remote from design conditions. The results of the study show that IGCC power plants combining electric power generation and methanol synthesis offer considerable scope for enhancing operating flexibility and load modulation capabilities of coal gasification power plants. The plants designed for advanced liquid phase methanol synthesis process performed best in terms of overall efficiency, plant layout and operating flexibility.

00/03390 Intrinsic reaction kinetics of methane steam reforming on a nickel/zirconia anode

China depends for most of its energy on coal – a situation that is likely to persist in the light of the abundance of its coal resources, the paucity of its oil and gas resources, and the reluctance of the government to allow China to become overly dependent on energy imports. The challenge is to find ways to use coal without the enormous air pollution damage caused by current conversion technologies and with greatly reduced carbon dioxide (CO2) emissions. A coal energy system for China is proposed that could ultimately be characterized by near-zero emissions of both air pollutants and greenhouse gases.The key enabling technology is oxygen-blown (O2–blown) gasification to generate synthesis gas from coal. This technology is used in commercially ready integrated gasification combined-cycle power plants that can provide electricity with air pollutant emissions as low as emission levels for natural gas combined-cycle plants. O2-blown gasification is not yet used in China's energy sector, although the technology is well-established in China's chemical process industry.The key enabling strategy, which would often lead to attractive energy costs without further technological advances, is “polygeneration” – the co-production from synthesis gas of at least electricity and one or more clean synthetic fuels (e.g., dimethyl ether (DME), Fischer-Tropsch (F-T) liquids, hydrogen (H2)) and often also chemicals, town gas, and/or industrial process heat. The products of polygeneration could be used in the near term to serve a wide range of energy needs with extremely low levels of air pollutant emissions.In such polygeneration configurations CO2 can often be produced in relatively pure streams as a co-product as a result of processing to increase the synthetic fuel's hydrogen-to-carbon ratio. In the near term this CO2 might be used profitably for enhanced oil recovery or enhanced recovery of methane from deep beds of unminable coal where resource recovery opportunities exist.For the longer term the potential exists for evolving the coal energy system to the co-production primarily of electricity and H2 for serving urban areas, with most of the carbon in the coal ending up as CO2 that is sequestered in geological reservoirs such as in depleted oil and natural gas fields and deep saline aquifers at low incremental cost – even where there are no opportunities for using the CO2 for enhanced resource recovery. The H2 so produced would be used for fueling zero-polluting fuel-cell vehicles, for distributed cogeneration (combined heat and power) applications in stationary fuel cells, and for cooking and heating applications as well.A third clean carbon-based synthetic fuel might also be needed for serving rural markets that would be difficult to serve with H2, unless there are breakthroughs in H2 storage technology. DME is a strong candidate for becoming the “third” clean energy carrier for China.Evolving a coal-based energy system that would be characterized ultimately by near-zero emissions of air pollutants and greenhouse gases would probably involve shifting the center of gravity for central-station power generation to the chemical process industries that would ultimately be co-producing as their major products electricity, H2, and (perhaps) DME. Ongoing structural reforms in the electric power sector that encourage greater competition in power generation would facilitate the realization of this vision for coal.

Effect of supplementary firing on the performance of an integrated gasification combined cycle power plant

The effect of supplementary firing on the performance of an integrated gasification combined cycle (IGCC) power plant is studied. The results are presented with respect to a simple ‘unfired’ IGCC power plant with single pressure power generation for both the gas and the steam cycles as reference. The gases are assumed as real with variable specific heats. It is found that the most favourable benefit of supplementary firing can be obtained for a low temperature ratio R T only. For higher R T, only a gain in work output is possible with a reverse effect on the overall efficiency of the plant. The second law analysis reveals that the exergy loss in the heat-recovery steam generator is most significant as the amount of supplementary firing increases. It is also noteworthy that, although the total exergy loss of the plant decreases with higher supplementary firing for a low R T (= 3.0), the reverse is the case for a higher R T (= 6.0).

00/00446 Comparison between IGCC and supercritical power plant processes

In recent years great deal of research work has been done to improve the efficiency of coal fired power plants. There are principally two different ways to increase the efficiency. The first is to increase the steam parameters in a conventional steam process and the other is to develop combined cycles for coal based on integrated gasification combined cycle (IGCC) or pressurized fluidized bed (PFBC) technology. For supercritical processes, the parameters of interest are turbine inlet pressure and temperature. Parameters that must be optimized are the number of reheaters, reheat pressure and temperature, the number of feed water preheaters and extraction pressure. In this work the future possibilities of supercritical and IGCC processes were studied. Both supercritical and IGCC processor were optimized by using a PROcess SIMulation program (PROSIM). Parameter values for both cases were chosen to meet future expectations that will be achieved by improving steam and gas turbines and as well as boiler materials. Results showed that the net plant efficiency is increased by raising the inlet steam temperatures and pressures in a supercritical process, also gas turbine expander inlet temperature and pressure ratio in an IGCC process. In order to reach efficiencies over 50 %, the processmore » parameter values must be increased beyond what is possible today. Interesting result has been obtained by increasing the gasification temperature in the IGCC process. The net plant efficiency decreased if the process used Cold Gas Clean Up, but increased if Hot Gas Clean up was used.« less

99/01178 Oxidative conversion of hydrocarbons into synthesis gas and unsaturated hydrocarbons assisted by gliding electric arcs : Czernichowski, P. and Czernichowski, A. PCT Int. Appl. WO 98 30,524 (Cl. C07CS/32), 16 Jul 1998, FR Appl. 97/364, 13 Jan 1997, 31 pp.

Syngas processing often requires separation of CO2 and hydrogen for hydrogen production, and the resulting CO2-enriched stream presents an opportunity for simultaneous CO2 capture. For example, syngas-based integrated gasification combined cycle (IGCC) power plants are envisioned as an efficient means of producing power from coal where CO2 capture technologies can be applied relatively easily. Membrane technology is an attractive approach for CO2 capture because of inherent process advantages such as simplicity, reliability, compactness and modularity. This paper (Part II of a two-part study) performs techno-economic analysis for CO2-selective membranes in three hydrogen production or utilization applications: methane reformer/pressure swing adsorption processes, oxygen-blown coal-fired IGCC power plants using GE gasification technology, and air-blown coal-fired IGCC power plants using Transport Integrated Gasification (TRIG) technology. These processes require membranes with CO2/H2 selectivities of 10–20, which can be provided using PolarisTM membranes. Hybrid approaches using a combination of membrane and cryogenic processes are evaluated for the production of high-pressure liquid CO2 ready for utilization or sequestration. The optimal membrane CO2/H2 selectivity and influence of CO2 capture rate on the cost of CO2 capture are determined, providing general guidelines for future membrane development. The cost of CO2 capture with these membrane processes depends not only on the feed CO2 partial pressure, but on the feed CO2 concentration as well.

97/03871 Biological fossil CO 2 mitigation

China depends for most of its energy on coal – a situation that is likely to persist in the light of the abundance of its coal resources, the paucity of its oil and gas resources, and the reluctance of the government to allow China to become overly dependent on energy imports. The challenge is to find ways to use coal without the enormous air pollution damage caused by current conversion technologies and with greatly reduced carbon dioxide (CO2) emissions. A coal energy system for China is proposed that could ultimately be characterized by near-zero emissions of both air pollutants and greenhouse gases.The key enabling technology is oxygen-blown (O2–blown) gasification to generate synthesis gas from coal. This technology is used in commercially ready integrated gasification combined-cycle power plants that can provide electricity with air pollutant emissions as low as emission levels for natural gas combined-cycle plants. O2-blown gasification is not yet used in China's energy sector, although the technology is well-established in China's chemical process industry.The key enabling strategy, which would often lead to attractive energy costs without further technological advances, is “polygeneration” – the co-production from synthesis gas of at least electricity and one or more clean synthetic fuels (e.g., dimethyl ether (DME), Fischer-Tropsch (F-T) liquids, hydrogen (H2)) and often also chemicals, town gas, and/or industrial process heat. The products of polygeneration could be used in the near term to serve a wide range of energy needs with extremely low levels of air pollutant emissions.In such polygeneration configurations CO2 can often be produced in relatively pure streams as a co-product as a result of processing to increase the synthetic fuel's hydrogen-to-carbon ratio. In the near term this CO2 might be used profitably for enhanced oil recovery or enhanced recovery of methane from deep beds of unminable coal where resource recovery opportunities exist.For the longer term the potential exists for evolving the coal energy system to the co-production primarily of electricity and H2 for serving urban areas, with most of the carbon in the coal ending up as CO2 that is sequestered in geological reservoirs such as in depleted oil and natural gas fields and deep saline aquifers at low incremental cost – even where there are no opportunities for using the CO2 for enhanced resource recovery. The H2 so produced would be used for fueling zero-polluting fuel-cell vehicles, for distributed cogeneration (combined heat and power) applications in stationary fuel cells, and for cooking and heating applications as well.A third clean carbon-based synthetic fuel might also be needed for serving rural markets that would be difficult to serve with H2, unless there are breakthroughs in H2 storage technology. DME is a strong candidate for becoming the “third” clean energy carrier for China.Evolving a coal-based energy system that would be characterized ultimately by near-zero emissions of air pollutants and greenhouse gases would probably involve shifting the center of gravity for central-station power generation to the chemical process industries that would ultimately be co-producing as their major products electricity, H2, and (perhaps) DME. Ongoing structural reforms in the electric power sector that encourage greater competition in power generation would facilitate the realization of this vision for coal.

Exergoeconomic Evaluation of a KRW-Based IGCC Power Plant

In a study supported by the U. S. Department of Energy, several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. One of these configurations was analyzed from the exergoeconomic (thermoeconomic) viewpoint. This design configuration uses an air-blown KRW gasifier, hot gas cleanup, and two General Electric MS7001F advanced combustion turbines. Operation at three different gasification temperatures was considered. The detailed exergoeconomic evaluation identified several changes for improving the cost effectiveness of this IGCC design configuration. These changes include the following: decreasing the gasifier operating temperature, enhancing the high-pressure steam generation in the gasification island, improving the efficiency of the steam cycle, and redesigning the entire heat exchanger network. Based on the cost information supplied by the M. W. Kellogg Company, an attempt was made to calculate the economically optimal exergetic efficiency for some of the most important plant components.

Exergetic Comparison of Two KRW-Based IGCC Power Plants

In studies supported by the U.S. Department of Energy and the Electric Power Research Institute, several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. Two of these configurations are compared here from the exergetic viewpoint. The first design configuration (case 1) uses an air-blown KRW gasifier and hot gas cleanup while the second configuration (reference case) uses an oxygen-blown KRW gasifier and cold gas cleanup. Each case uses two General Electric MS7001F advanced combustion turbines. The exergetic comparison identifies the causes of performance difference between the two cases: differences in the exergy destruction of the gasification system, the gas turbine system, and the gas cooling process, as well as differences in the exergy loss accompanying the solids to disposal stream. The potential for using (a) oxygen-blown versus air-blown-KRW gasifiers, and (b) hot gas versus cold gas cleanup processes was evaluated. The results indicate that, among the available options, an oxygen-blown KRW gasifier using in-bed desulfurization combined with an optimized hot gas cleanup process has the largest potential for providing performance improvements.

Advantages of an integrated system for hot gas filtration using rigid ceramic elements

Removing particles from gases at high temperatures and pressures has potential for Increased efficiency In advanced coal-fired power generation systems like Pressurised Fluidised Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) processes, and for adhering to environmental regulations for dust emissions In waste incineration and Fluid Catalyst Cracking (FCC) processes. This article outlines the main advantages and prerequisites In designing and selecting an overall solution for a high-efficiency hot gas filter system, and presents development efforts resulting In effective on-line cleaning. The use of membrane-coated silicon carbide (SIC) filter elements turned out to be most effective In terms of filtration efficiency, mechanical and chemical stability, and long-term durability Including low pressure drops. An example of a hot gas filter, removing flyslag from a 250 MW el IGCC power plant, is presented.

Development of simplified IGCC-processes for biofuels: Supporting gasification research at VTT

Gasification research-and-development activities in Finland are focused on the development of simplified integrated gasification combined-cycle power plants based on air-blown gasification and hot-gas cleaning. This research is mainly concentrated on the utilization of peat and different wood wastes. Effective utilization of these fuels, which are the only indigenous fuels in Finland, is crucially important for the Finnish energy economy. Pressurized-fluidized-bed gasification of biofuels and hot-gas cleaning from tars, particulates, and alkali metals are extensively studied at the Technical Research Centre of Finland. A brief review of the current experimental gasification research is presented in this paper.

Central station thermal energy storage for peak and intermediate load power generation

The application of thermal energy storage to central station power plants allows baseload power-generating technologies to provide peak and intermediate load electric power. DOE has provided funding for a study to investigate the technical and economic feasibility of using molten nitrate salt thermal energy storage in conjunction with pulverized-coal-fired and integrated gasification combined-cycle power plants. The results suggest that the use of thermal energy storage is technically feasible and can reduce the cost of generating peak and intermediate load electric power from coal by between 5% and 20%.

Second generation gasification combined-cycle power plants for US utilities—Detailed performance and cost estimates

Studies of integrated coal gasification combined-cycle power plants carried out by four US manufactures and process firms are summarised and their results compared on an equivalent basis. The results of these studies indicate that integrated gasification combined-cycle power plants based on the oxygen-blown Texaco entrained flow gasifier and employing current technology gas turbines have the potential for providing substantial performance improvements over conventional coal-fired steam stations with flue gas desulphurisation.