Thermodynamic Analysis and Optimization of IT-SOFC-Based Integrated Coal Gasification Fuel Cell Power Plants

Author(s):  
Matteo C. Romano ◽  
Stefano Campanari ◽  
Vincenzo Spallina ◽  
Giovanni Lozza

This work discusses the thermodynamic analysis of integrated gasification fuel cell plants, where a simple cycle gas turbine works in a hybrid cycle with a pressurized intermediate temperature–solid oxide fuel cell (SOFC), integrated with a coal gasification and syngas cleanup island and a bottoming steam cycle (reflecting the arrangement of integrated gasification combined cycle (IGCC) plants) to optimize heat recovery and maximize efficiency. This work addresses the optimization of the plant layout, discussing the effect of the SOFC fuel utilization factor and the possibility of a fuel bypass to increase the gas turbine total inlet temperature and reduce the plant expected investment costs. Moreover, a discussion of technological issues related to the feasibility of the connection among the plant high temperature components is carried out, presenting the effects of different limitations of the maximum temperatures reached by the plant piping. With the proposed plant configurations, which do not include—apart from the SOFC—any component far from the nowadays best available technologies, a net electric lower heating value efficiency approaching 52–54% was calculated, showing a remarkable increase with respect to state-of-the-art advanced IGCCs.

Author(s):  
Eric Liese

This paper examines the arrangement of a solid oxide fuel cell (SOFC) within a coal gasification cycle, this combination generally being called an integrated gasification fuel cell cycle. This work relies on a previous study performed by the National Energy Technology Laboratory (NETL) that details thermodynamic simulations of integrated gasification combined cycle (IGCC) systems and considers various gasifier types and includes cases for 90% CO2 capture (2007, “Cost and Performance Baseline for Fossil Energy Plants, Vol. 1: Bituminous Coal and Natural Gas to Electricity,” National Energy Technology Laboratory Report No. DOE/NETL-2007/1281). All systems in this study assume a Conoco Philips gasifier and cold-gas clean up conditions for the coal gasification system (Cases 3 and 4 in the NETL IGCC report). Four system arrangements, cases, are examined. Cases 1 and 2 remove the CO2 after the SOFC anode. Case 3 assumes steam addition, a water-gas-shift (WGS) catalyst, and a Selexol process to remove the CO2 in the gas cleanup section, sending a hydrogen-rich gas to the fuel cell anode. Case 4 assumes Selexol in the cold-gas cleanup section as in Case 3; however, there is no steam addition, and the WGS takes places in the SOFC and after the anode. Results demonstrate significant efficiency advantages compared with IGCC with CO2 capture. The hydrogen-rich case (Case 3) has better net electric efficiency compared with typical postanode CO2 capture cases (Cases 1 and 2), with a simpler arrangement but at a lower SOFC power density, or a lower efficiency at the same power density. Case 4 gives an efficiency similar to Case 3 but also at a lower SOFC power density. Carbon deposition concerns are also discussed.


2015 ◽  
Vol 3 (1) ◽  
pp. 178
Author(s):  
Mohsen Darabi ◽  
Mohammad Mohammadiun ◽  
Hamid Mohammadiun ◽  
Saeed Mortazavi ◽  
Mostafa Montazeri

<p>Electricity is an indispensable amenity in present society. Among all those energy resources, coal is readily available all over the world and has risen only moderately in price compared with other fuel sources. As a result, coal-fired power plant remains to be a fundamental element of the world's energy supply. IGCC, abbreviation of Integrated Gasification Combined Cycle, is one of the primary designs for the power-generation market from coal-gasification. This work presents a in the proposed process, diluted hydrogen is combusted in a gas turbine. Heat integration is central to the design. Thus far, the SGR process and the HGD unit are not commercially available. To establish a benchmark. Some thermodynamic inefficiencies were found to shift from the gas turbine to the steam cycle and redox system, while the net efficiency remained almost the same. A process simulation was undertaken, using Aspen Plus and the engineering equation solver (EES).The The model has been developed using Aspen Hysys® and Aspen Plus®. Parts of it have been developed in Matlab, which is mainly used for artificial neural network (ANN) training and parameters estimation. Predicted results of clean gas composition and generated power present a good agreement with industrial data. This study is aimed at obtaining a support tool for optimal solutions assessment of different gasification plant configurations, under different input data sets.</p>


Author(s):  
Walter W. Shelton ◽  
Robin W. Ames ◽  
Richard A. Dennis ◽  
Charles W. White ◽  
John E. Plunkett ◽  
...  

The U.S. Department of Energy’s (DOE) provides a worldwide leadership role in the development of advanced fossil fuel-based energy conversion technologies, with a focus on electric power generation with carbon capture and storage (CCS). As part of DOE’s Office of Fossil Energy, the National Energy Technology Laboratory (NETL) implements research, development, and demonstration (RD&D) programs that address the challenges of reducing greenhouse gas emissions. To meet these challenges, NETL evaluates advanced power cycles that will maximize system efficiency and performance, while minimizing CO2 emissions and the costs of CCS. NETL’s Hydrogen Turbine Program has sponsored numerous R&D projects in support of Advanced Hydrogen Turbines (AHT). Turbine systems and components targeted for development include combustor technology, materials research, enhanced cooling technology, coatings development, and more. The R&D builds on existing gas turbine technologies and is intended to develop and test the component technologies and subsystems needed to validate the ability to meet the Turbine Program goals. These technologies are key components of AHTs, which enable overall plant efficiency and cost of electricity (COE) improvements relative to an F-frame turbine-based Integrated Gasification Combined Cycle (IGCC) reference plant equipped with carbon capture (today’s state-of-the-art). This work has also provided the basis for estimating future IGCC plant performance based on a Transformational Hydrogen Turbine (THT) with a higher turbine inlet temperature, enhanced material capabilities, reduced air cooling and leakage, and higher pressure ratios than the AHT. IGCC cases from using system-level AHT and THT gas turbine models were developed for comparisons with an F-frame turbine-based IGCC reference case and for an IGCC pathway study. The IGCC pathway is presented in which the reference case (i.e. includes F-frame turbine) is sequentially-modified through the incorporation of advanced technologies. Advanced technologies are considered to be either 2nd Generation or Transformational, if they are anticipated to be ready for demonstration by 2025 and 2030, respectively. The current results included the THT, additional potential transformational technologies related to IGCC plant sections (e.g. air separation, gasification, gas cleanup, carbon capture, NOx reduction) are being considered by NETL and are topics for inclusion in future reports.


2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1187-1197 ◽  
Author(s):  
Marek Jaszczur ◽  
Michal Dudek ◽  
Zygmunt Kolenda

One of the most advanced and most effective technology for electricity generation nowadays based on a gas turbine combined cycle. This technology uses natural gas, synthesis gas from the coal gasification or crude oil processing products as the energy carriers but at the same time, gas turbine combined cycle emits SO2, NOx, and CO2 to the environment. In this paper, a thermodynamic analysis of environmentally friendly, high temperature gas nuclear reactor system coupled with gas turbine combined cycle technology has been investigated. The analysed system is one of the most advanced concepts and allows us to produce electricity with the higher thermal efficiency than could be offered by any currently existing nuclear power plant technology. The results show that it is possible to achieve thermal efficiency higher than 50% what is not only more than could be produced by any modern nuclear plant but it is also more than could be offered by traditional (coal or lignite) power plant.


Author(s):  
Abbie Layne ◽  
Scott Samuelsen ◽  
Mark Williams ◽  
Patricia Hoffman

A hybrid heat engine results from the fusion of a heat engine with a non-heat-engine based cycle (unlike systems). The term combined cycle, which refers to similar arrangements, is reserved for the combination of two or more heat engines (like systems). The resulting product of the integration of a gas turbine and a fuel cell is referred to here as a hybrid heat engine or “Hybrid” for short. The intent of this paper is to provide, to the gas turbine community, a review of the present status of hybrid heat engine technologies. Current and projected activities associated with this emerging concept are also presented. The National Energy Technology Laboratory (NETL) is collaborating with other sponsors and the private sector to develop a Hybrid Program. This program will address the issues of technology development, integration, and ultimately the demonstration of what may be the most efficient of power plants in the world — the Hybrid System. Analyses of several Hybrid concepts have indicated the potential of ultra-high efficiencies (approaching 80%). In the Hybrid, the synergism between the gas turbine and fuel cell provides higher efficiencies and lower costs than either system can alone. Testing of the first Hybrid concept has been initiated at the National Fuel Cell Research Center (NFCRC).


Author(s):  
Mayank Maheshwari ◽  
Onkar Singh

Abstract Performance of gas/steam combined cycle power plants relies upon the performance exhibited by both gas based topping cycle and steam based bottoming cycle. Therefore, the measures for improving the performance of the gas turbine cycle and steam bottoming cycle eventually result in overall combined cycle performance enhancement. Gas turbine cooling medium affects the cooling efficacy. Amongst different parameters in the steam bottoming cycle, the deaerator parameter also plays its role in cycle performance. The present study analyzes the effect of deaerator’s operating pressure being varied from 1.6 bar to 2.2 bar in different configurations of simple and reheat gas/steam combined cycle with different cooling medium for fixed cycle pressure ratio of 40, turbine inlet temperature of 2000 K and ambient temperature of 303 K with varying ammonia mass fraction from 0.6 to 0.9. Analysis of the results obtained for different combined cycle configuration shows that for the simple gas turbine and reheat gas turbine-based configurations, the maximum work output of 643.78 kJ/kg of air and 730.87 kJ/kg of air respectively for ammonia mass fraction of 0.6, cycle efficiency of 54.55% and 53.14% respectively at ammonia mass fraction of 0.7 and second law efficiency of 59.71% and 57.95% respectively at ammonia mass fraction of 0.7 is obtained for the configuration having triple pressure HRVG with ammonia-water turbine at high pressure and intermediate pressure and steam turbine operating at deaerator pressure of 1.6 bar.


Author(s):  
Onkar Singh ◽  
R. Yadav

Combined cycle based power plants and their development and application for energy efficient base load power generation necessitates enforced cooling to maintain the topping cycle gas turbine blade temperature at permissible levels, attributed to the increased turbine inlet temperature and compressor pressure ratio, for the improved performance and reliability of combined cycle. The mathematical model based on expansion path inside gas turbine considering dilution of mainstream and aerodynamic mixing losses for a range of cooling medium has been developed based on internal, film, transpiration cooling technologies and a combination of these. It is found that the appreciation of a cycle configuration as well as the optimum pressure ratio and peak temperature vary significantly with types of cooling technology adopted. Steam cooling for rotor appears to be a very potential cooling medium, when employed with an appropriate cooling technology. This paper deals with the thermodynamic analysis of turbine cooling using, different means of cooling i.e. air, water and steam.


Author(s):  
Hossein Ghezel-Ayagh ◽  
Stephen Jolly ◽  
Keith E. Davis ◽  
James Walzak ◽  
Dilip Patel ◽  
...  

Integrated Gasification Fuel Cell (IGFC) power plants incorporating solid oxide fuel cells (SOFCs) are attractive alternatives to traditional pulverized coal-fired and Integrated Gasification Combined Cycle (IGCC) power plants. IGFC systems are projected to achieve electrical generation efficiencies greater than 50% based on high heating value of coal, while separating at least 90% of the carbon dioxide emissions for capture and environmentally secure storage. A comprehensive IGFC system design and optimization study is presented based on recent SOFC performance testing and technology advancements. Details of the system power island cost break-down are also presented, indicating the cost-competitiveness of IGFC systems relative to other coal-fueled power generation technologies. Comparisons of the projected IGFC system efficiency and water consumption are made to pulverized coal-fired and IGCC power plants.


Author(s):  
Kazuto Kakio ◽  
Y. Kawata

Recently, the number of gas turbine combined cycle plants is rapidly increasing in substitution of nuclear power plants. The turbine inlet temperature (TIT) is being constantly increased in order to achieve higher efficiency. Therefore, the improvement of the cooling technology for high temperature gas turbine blades is one of the most important issue to be solved. In a gas turbine, the main flow impinging at the leading edge of the turbine blade generates a so called horseshoe vortex by the interaction of its boundary layer and generated pressure gradient at the leading edge. The pressure surface leg of this horseshoe vortex crosses the passage and reaches the blade suction surface, driven by the pressure gradient existing between two consecutive blades. In addition, this pressure gradient generates a crossflow along the endwall. This all results into a very complex flow field in proximity of the endwall. For this reason, burnouts tend to occur at a specific position in the vicinity of the leading edge. In this research, a methodology to cool the endwall of the turbine blade by means of film cooling jets from the blade surface is proposed. The cooling performance and heat transfer coefficient distribution is investigated using the transient thermography method. CFD analysis is also conducted to know the phenomena occurring at the end wall and calculate the heat transfer distribution.


Author(s):  
Sandro Barros Ferreira ◽  
Pericles Pilidis

The use of biomass as gas turbine combined cycle fuels is broadly seen as one of the alternatives to diminish greenhouse gas emissions, mainly CO2, due to the efficiency delivered by such systems and the renewable characteristic of biomass itself. Integrated gasification cycles, BIGGT, are the current technology available; however the gasification system severely penalizes the power plant in terms of efficiency and demands modifications in the engine to accommodate the large fuel mass flow. This gives an opportunity to improvements in the current technologies and implementation of new ones. This paper intends to analyze new alternatives to the use of solid fuels in gas turbines, from the economical point of view, through the use of external combustion, EFGT, discussing its advantages and limitations over the current technology. The results show that both EFGT and BIGGT technologies are economically competitive with the current natural gas fired gas turbines. However, BIGGT power plants are still in pilot scale and the EFGT plants need further technological development. Thermodynamically speaking, the inherently recuperative characteristic of the EFGT gas turbine engine makes it well suited to the biomass market. The thermal efficiency of this cycle is higher than the BIGGT system. Furthermore, its fuel flexibility and negligible pre-treatmet is another advantage that makes it an interesting option for the Brazilian market.


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