Integrated Coal Gasification Combined Cycle Plant Research Articles

Process Evaluation of Carbon Dioxide Capture for Coal-Fired Power Plants

Carbon capture is a promising technology for carbon dioxide (CO2) removal from large stationary CO2 sources. The effects of carbon dioxide capture process on output efficiency of fossil power plants were investigated. Supercritical pulverized coal and integrated coal gasification combined cycle (IGCC) were assumed as model coal-fired power plants for this investigation. Heat-driven and pressure-driven CO2 capture processes such as chemical absorption and physical adsorption were assumed for CO2 capture process. In this study, these technologies were evaluated and compared under the unified basis and conditions by using the commercial process simulator. For IGCC plant, the efficiency penalty by installing water-gas shift reaction was also investigated. Gross and net power generation, efficiency and the efficiency penalty by CO2 capture process were calculated. Heat duty for CO2 capture process and CO2 compression conditions were varied, and those effects on the efficiency penalty were obtained. The results provide a guideline for development of CO2 capture process of power plants.

Progress and utilization of Nakoso 250 MW air-blown IGCC demonstration project

Integrated coal Gasification Combined Cycle (IGCC) is a highly effective power generation system that the gas turbine is operated with the gasified coal in the gasifier. Clean Coal Power R&D Co., Ltd. had been conducting various tests for commercialization with the Nakoso IGCC demonstration plant since September 2007. The plant consists of air-blown gasifier, wet gas clean-up system and 1,200°C class gas turbine to produce 250 MW-gross electricity. Reliability was confirmed by 2,238 h of continuous operation, 18,788 h of accumulated operation and the resulting net thermal efficiency was 42.9% (LHV basis). Various types of coal have been successfully tested, such as North American coal, Indonesian coal, Russian coal and Columbian coal in addition to Chinese plant-designed coal. Although the Great East Japan Earthquake and Tsunami has caused severe damages to plant in March 2011, our IGCC swiftly restored its operation within 4.5 month and has been maintaining stable operation for demonstration project. The demonstration project was finished in March 2013 and the Nakoso IGCC plant is operated commercially by Joban Joint Power Co., Ltd. as high efficiency power generating station.

Effects of supplementary biomass firing on the performance of combined cycle power generation: A comparison between NGCC and IGCC plants

In the present work, effects of biomass supplementary firing on the performance of fossil fuel fired combined cycles have been analyzed. Both natural gas fired combined cycle (NGCC) and integrated coal gasification combined cycle (IGCC) have been considered in the study. The efficiency of the NGCC plant monotonically reduces with the increase in supplementary firing, while for the IGCC plant the maximum plant efficiency occurs at an optimum degree of supplementary firing. This difference in the nature of variation of the efficiency of two plants under the influence of supplementary firing has been critically analyzed in the paper. The ratings of different plant equipments, fuel flow rates and the emission indices of CO2 from the plants at varying degree of supplementary firing have been evaluated for a net power output of 200 MW. The fraction of total power generated by the bottoming cycle increases with the increase in supplementary firing. However, the decrease in the ratings of gas turbines is much more than the increase in that of the steam turbines due to the low work ratio of the topping cycle. The NGCC plants require less biomass compared to the IGCC under identical condition. A critical degree of supplementary firing has been identified for the slag free operation of the biomass combustor. The performance parameters, equipment ratings and fuel flow rates for no supplementary firing and for the critical degree of supplementary biomass firing have been compared for the NGCC and IGCC plants.

Corrosion of Type 316L Stainless Steel Piping in Synthetic Gas Plants

Corrosion behavior of Type 316L (UNS S31603) stainless steel piping used in integrated coal gasification combined cycle (IGCC) plant facilities processing coal (0.9 MPa to 1.1 MPa and 150°C to 300°C) and industrial waste (0.11 MPa and 40°C to 60°C) was explained using scanning electron microscopy-energy dispersive x-ray spectrometry (SEM/EDS), x-ray diffraction (XRD), and a thermodynamic Ellingham-Pourbaix stability diagram. Material wastage and pitting were observed on the inner wall of Type 316L stainless steel piping used in Institute for Advanced Engineering (IAE) coal and industrial waste syngas plant facilities after 720 h and 170 h (total hours) of operation, respectively. Relevant corrosion mechanism was suggested based on SEM/EDS examination and thermodynamic inferences: the observed material wastage and corrosion behavior of the Type 316L piping material cut off from the coal syngas IGCC plant were explained by combined effects of evaporation of iron chlorides and subsequent transformation into thin oxides. On the other hand, the pitting corrosion phenomenon observed on the inner wall of Type 316L piping cut off from industrial waste processing IGCC plant was attributed to modified pitting mechanism caused by the preferential growth of corrosion pits in horizontal direction under aqueous condensate environment containing hydrochloric acid (HCl).

Performance of a Multiple-Injection Dry Low NOx Combustor With Hydrogen-Rich Syngas Fuels

An oxygen-blown integrated coal gasification combined cycle (IGCC) plant with precombustion carbon dioxide capture and storage (CCS) is one of the most promising means of zero-emission generation of power from coal. In an IGCC plant with CCS, hydrogen-rich syngas with a wide variation of hydrogen contents is supplied to a gas turbine. Such hydrogen-rich syngas poses a great challenge to a low NOx combustor based on premixed combustion technology, because its high flame speed, low ignition energy, and broad flammability limits can cause flashback and/or autoignition. On the contrary, a diffusion combustor suffers from the high flame temperature of syngas and the resulting high NOx emission. The authors applied a “multi-injection burner” concept to a preliminary burner for hydrogen-rich syngas simulating that from IGCC with CCS. In a preliminary experiment under atmospheric pressure, the multi-injection burner worked without any flashback or any blowout. A prototype multicluster combustor based on the results of that preliminary study was made to be a dry low NOx combustor for hydrogen-rich syngas of IGCC with CCS. It was tested in experiments, which were carried out under medium pressure (0.6 MPa) using test fuels simulating syngas from IGCC with a 0% carbon capture rate, a 30% carbon capture rate, and a 50% carbon capture rate. The test fuels contained hydrogen, methane, and nitrogen, and had a hydrogen content ranging from 40% to 65%.The following conclusions were drawn from the test results: (1) the tested combustor allows the stable combustion of fuels simulating 0%, 30%, and 50% CCS, (2) a convex perforated plate swirler is effective to suppress combustion oscillation, which allows NOx emissions to be less than 10 ppm through the variation of fuel simulating 0%, 30%, and 50% CCS, (3) the extended stable combustion region and enhanced entrainment and mixing due to the convex perforated plate improves the cooling of the combustor liner metal to be less than the liner metal temperature criterion.

Exergy recuperative CO2 gas separation in pre-combustion capture

The integrated coal gasification combined cycle (IGCC) can achieve higher power generation efficiency than conventional pulverized coal combustion power plants. However, a CO2 capture process prevents improving power generation efficiency of IGCC, because CO2 separation from gas mixtures requires huge amounts of energy. Therefore, in this study, we analyzed the CO2 separation process in the pre-combustion capture process using a process simulator (PRO/II) in the steady state, and proposed a new process using a modularity based on self-heat recuperation (SHR) technology to decrease energy consumption. Pre-combustion capture was applied in the IGCC plant, which involved coal gasification and CO-shift conversion with CO2 capture. The results show that the energy consumption for the CO2 separation process using SHR was decreased by two-thirds. This means that the power generation efficiency can be improved by SHR compared with conventional IGCC with a CO2 capture process.

The long-term life cycle private and external costs of high coal usage in the US

Using four times as much coal in 2050 for electricity production need not degrade air quality or increase greenhouse gas emissions. Current SO x and NO x emissions from the power sector could be reduced from 12 to less than 1 and from 5 to 2 million tons annually, respectively, using advanced technology. While direct CO 2 emissions from new power plants could be reduced by over 87%, life cycle emissions could increase by over 25% due to the additional coal that is required to be mined and transported to compensate for the energy penalty of the carbon capture and storage technology. Strict environmental controls push capital costs of pulverized coal (PC) and integrated coal gasification combined cycle (IGCC) plants to $1500–1700/kW and $1600–2000/kW, respectively. Adding carbon capture and storage (CCS) increases costs to $2400–2700/kW and $2100–3000/kW (2005 dollars), respectively. Adding CCS reduces the 40–43% efficiency of the ultra-supercritical PC plant to 31–34%; adding CCS reduces the 32–38% efficiency of the GE IGCC plant to 27–33%. For IGCC, PC, and natural gas combined cycle (NGCC) plants, the carbon dioxide tax would have to be $53, $74, and $61, respectively, to make electricity from a plant with CCS cheaper. Capturing and storing 90% of the CO 2 emissions increases life cycle costs from 5.4 to 11.6 cents/kWh. This analysis shows that 90% CCS removal efficiency, although being a large improvement over current electricity generation emissions, results in life cycle emissions that are large enough that additional effort is required to achieve significant economy-wide reductions in the US for this large increase in electricity generation using either coal or natural gas.

Degradation of gas turbine blade materials in integrated coal-gasification combined cycle plant

Degradation of gas turbine blade materials in integrated coal-gasification combined cycle plant

Degradation of gas turbine blade materials in integrated coal-gasification combined cycle plant

Interest in the integrated coal-gasification combined cycle plant (IGCC) has increased because of its high efficiency. However, degradation of gas turbine component materials has not been studied so far. Therefore, the purpose of this study is to investigate the corrosion behaviors of these materials in an actual coal gas combustion environment. Our test facility was constructed near the coal-gasification test facility (CGT) at the Aioi works of Ishikawajima-Harima Heavy Industries Co., Ltd. Several superalloy (René80H and FSX414) and coating systems (CoCrAlY, CoNiCrAlY and TBC) were exposed in the coal gas combustion environment at 1123, 1223 and 1323 K up to 350 h. After these tests, the weight change of each specimen was measured. Morphologies of products and element distributions at their surfaces were observed with SEM and EPMA. It is concluded that not only high- temperature oxidation and sulfidation but also ash deposition has a remarkable influence on the degradation of gas turbine blade materials.

Performance improvement of integrated coal gasification combined cycle by a new approach in exergy analysis

A new approach to exergy analysis is proposed for examing the consumption of energy as the minimum driving force and of exergy consumption that is avoidable, and for the development of a method to predict the alternatives in system improvement by exploring possible reduction in the avoidable exergy consumption. Also suggested in this study is a dimensionless parameter γAVO, which is the ratio of avoidable exergy consumption over total fuel energy input to the system. Detailed analyses, including the calculation of exergy consumption, exergy loss and avoidable exergy consumption, were conducted for each component in the syngas cooling system in the Integrated coal Gasification Combined Cycle (IGCC) plant, to prove the effective application of the proposed method. The analysis showed that the rank of avoidable exergy consumption was different from that of total energy consumption, and hence it confirmed that an energy analysis by conventional methods misled the focus of improvement in system design. The methodology developed in this study offers a new approach for system designers to analyze and to improve the performance of a complex energy system such as an IGCC plant.

A104 数値解析による石炭ガス化炉内の灰挙動予測

The Integrated coal Gasification Combined Cycle (IGCC) power generation system is expected as a clean coal utilization technology in next generation, so some projects if IGCC system have been organized in Europe and USA. In Japan, the experimental researches with the 2T/D test-scale gasifier and the 200T/D pilot-scale gasifier have been completed, and a project of demonstrative IGCC plant will be started in the near future. In this paper, a numerical simulation of the 200T/D pilot-scale coal gasifier is carried out. To feed-back the results of numerical simulation into the design and operation of the coal gasifier, it is important to develop some method which specifies the phenomena in the coal gasifier. This paper presents a new procedure which can be estimated the trap-rate of the ash particles in combustor with the results of numerical simulation. The influence of the change in the burner arrangement and/or shape of gasifier on the trap-rate of the ash particles is estimated by this procedure.

Integration of fossil and renewable energy technologies to mitigate carbon dioxide

This paper analyzes several integrations of photovoltaics (PV) and integrated coal gasification combined cycle (IGCC) technologies to reduce carbon dioxide. In one of these integrations, liquid hydrocarbon transportation fuels are produced by reacting the carbon dioxide from the IGCC plant with hydrogen produced from PV electrolysis of water. This system appears to be cost competitive with a hydrogen economy alternative for future estimates of system performance and costs.

The Unique Challenges of Cryogenic Distillation Column Control for Integrated Coal Gasification Combined Cycle Applications

Abstract The world’s largest coal gasification plant for electricity generation is being built in Buggenum, The Netherlands and will be on-stream in 1993. Integrated coal gasification combined cycle (ICGCC) power plants are designed to convert coal to electricity in an environmentally superior and more efficient manner than conventional power plants. The ICGCC plant is characterized by the integration of a coal gasifier, steam and gas turbine units and an air separation unit (ASU) that provides oxygen and nitrogen. Because of the high degree of integration within the Buggenum facility, the ability of the air separation unit to respond to rapid changes in demand is a critical factor in the flexibility of the entire system. At the core of the air separation unit there is a system of tightly coupled, multicomponent, high-purity cryogenic distillation columns. This system will be subject to severe changes in process conditions including rapid product flow ramping rates, large pressure variations, and air supply pressures varying with the oxygen demand. Under all conditions tight purity specifications must be maintained on all the product streams. A program of dynamic modelling, simulation, and control system design was undertaken by Air Products at a very early stage in the plant design, prior to detailed equipment specification. This paper describes the approach taken to understand the dynamics of the proposed ASU under the expected load following conditions in order to verify the process design and to develop and optimise the control strategy. The work highlights the importance of incorporating control and operability considerations early during plant design.