Performance of Zero Emissions Integrated Gasification Hydrogen Combustion (ZE-IGHC) Power Plants With CO2 Removal

Author(s):  
Giorgio Cau ◽  
Daniele Cocco ◽  
Augusto Montisci

This paper concerns a performance evaluation of advanced zero emissions (NOx, SOx, CO and particulate, but also CO2), coal gasification integrated power plants with hydrogen combustion (ZE-IGHC). In ZE-IGHC power plants the hydrogen is produced through CO shift conversion and subsequent CO2 separation. The hydrogen is burned using pure oxygen in an internal combustion steam power plant with double combustion and thermodynamic regeneration. As a result of raw gas cleaning, CO2 separation and hydrogen combustion with oxygen, the ZE-IGHC power plant eliminates pollutant and greenhouse gas emissions. A comparative study of ZE-IGHC plant configurations based on different gasifiers and raw gas cooling options indicated that net efficiencies of up to about 50% can be achieved by resorting to configurations based on dry-feed gasifiers and raw gas cooling heat recovery with steam production. The simpler and cheaper plant configurations based on wet-feed gasifiers and raw gas quench systems give an efficiency penalty of about 3-4 % points. The ZE-IGHC power plant presented here can be a very attractive option for a near term, coal-fired power generation system. What is more, its major components are already adopted in conventional power plants and only the hydrogen combustors and the high temperature turbine require technology development.

Author(s):  
Rolf H. Kehlhofer

In the past 15 years the combined-cycle (gas/steam turbine) power plant has come into its own in the power generation market. Today, approximately 30 000 MW of power are already installed or being built as combined-cycle units. Combined-cycle plants are therefore a proven technology, showing not only impressive thermal efficiency ratings of up to 50 percent in theory, but also proving them in practice and everyday operation (1) (2). Combined-cycle installations can be used for many purposes. They range from power plants for power generation only, to cogeneration plants for district heating or combined cycles with maximum additional firing (3). The main obstacle to further expansion of the combined cycle principle is its lack of fuel flexibility. To this day, gas turbines are still limited to gaseous or liquid fuels. This paper shows a viable way to add a cheap solid fuel, coal, to the list. The plant system in question is a 2 × 150 MW combined-cycle plant of BBC Brown Boveri with integrated coal gasification plant of British Gas/Lurgi. The main point of interest is that all the individual components of the power plant described in this paper have proven their worth commercially. It is therefore not a pilot plant but a viable commercial proposition.


Author(s):  
M. Gambini ◽  
M. Vellini

In this paper the overall performance of a new advanced mixed cycle (AMC), fed by hydrogen-rich fuel gas, has been evaluated. Obviously, hydrogen must be produced and here we have chosen the coal gasification for its production, quantifying all the thermal and electric requirements. At first, a simple combination between hydrogen production section and power section is performed. In fact, the heat loads of the first section can be satisfied by using the various raw syngas cooling, without using some material streams taken from the power section, but also without using part of heat, available in the production section and rejected into the environment, in the power section. The final result is very poor: over 34%. Then, by using the Pinch Technology, a more efficient, even if more complex, solution can be conceived: in this case the overall efficiency is very interesting: 39%. These results are very similar to those of a combined cycle power plant, equipped with the same systems and analyzed under the same hypotheses. The final result is very important because the “clean” use of coal in new power plant types must be properly investigated: in fact coal is the most abundant and the cheapest fossil fuel available on earth; moreover, hydrogen production, by using coal, is an interesting outlook because hydrogen has the potential to become the main energy carrier in a future sustainable energy economy.


2018 ◽  
Vol 41 ◽  
pp. 02011 ◽  
Author(s):  
Olesya Aksenova ◽  
Evgenia Nikolaeva

The article seeks to examine the efficiency of applying means of mathematical processing and computer modeling of the work processes of gas cleaning facilities of power plants to optimize the process of planning and designing of future power plant in operation. A way of solution of the gas outbursts cleaning problem at the stage of designing measures for the development of waste processing systems through mathematical processing of expected volumes of gas outbursts and computer simulation of individual pieces of equipment and working areas as a whole is offered. The authors present the results of the processing of the projected technological processes and the gas outbursts cleaning facilities in terms of E-networks and using mathematical processing in the application Simulink, which allows to build a model of the device and to carry out calculations on the screen using the library of building blocks. A 3D model of the gas cleaning facilities, which allows to visualize the technological process and to compare it with theoretical calculations at the design stage of the future power plant and, if necessary, make changes to the project, has been created by means of computer modeling.


2006 ◽  
Vol 317-318 ◽  
pp. 81-84 ◽  
Author(s):  
Masahiro Kato ◽  
Yukishige Maezawa ◽  
Shin Takeda ◽  
Yoshikazu Hagiwara ◽  
Ryosuke Kogo ◽  
...  

A novel CO2 separation technique that employs the chemical reaction of lithium-containing oxides with CO2 has been developed. Since this method is effective in the temperature range of 450oC to 700oC, it has the advantages of enabling CO2 separation in power plants without lowering the temperature and of absorbing CO2 from the steam-methane reforming process at the same time. Because the absorption is exothermic and the steam reforming is endothermic, the energy loss is expected to be significantly reduced by combining the reactions. Hydrogen yields are expected to be higher because the equilibrium may be shifted by the removal of the CO2 byproduct. We have therefore proposed a pre-combustion CO2 capture system using lithium silicate and steam reforming. Bench-scale experiments were performed to measure the methane conversion and CO2 removal efficiency in order to evaluate the feasibility of the pre-combustion CO2 capture system. At temperatures of less than 650oC, the methane conversion in the case of mixture of catalyst and absorbent was higher than that in the case of catalyst alone. In addition, the CO2 removal efficiency is almost 90%. These results appear to indicate that pre-combustion CO2 capture combined with steam reforming is feasible.


Author(s):  
Wolfgang Sanz ◽  
Martin Braun ◽  
Herbert Jericha ◽  
Max F. Platzer

A modern energy system based on renewable energy like wind and solar power inevitably needs a storage system to provide energy on demand. Hydrogen is a promising candidate for this task. For the re-conversion of the valuable fuel hydrogen to electricity a power plant of highest efficiency is needed. In this work the Graz Cycle, a zero emission power plant based on the oxy-fuel technology, is proposed for this role. The Graz Cycle originally burns fossil fuels with pure oxygen and offers efficiencies up to 65 % due to the recompression of about half of the working fluid. The Graz Cycle is now adapted for hydrogen combustion with pure oxygen so that a working fluid of nearly pure steam is available. The changes in the thermodynamic layout are presented and discussed. The results show that the cycle is able to reach a net cycle efficiency based on LHV of 68.5 % if the oxygen is supplied “freely” from hydrogen generation by electrolysis. An additional parameter study shows the potential of the cycle for further improvements. The high efficiency of the Graz Cycle is also achieved by a close interaction of the components which makes part load operation more difficult. So in the second part of the paper strategies for part load operation are presented and investigated. The thermodynamic analysis predicts part load down to 30 % of the base load at remarkably high efficiencies.


Author(s):  
W. C. Yang ◽  
R. A. Newby ◽  
R. L. Bannister

Air-blown coal gasification for combined-cycle power generation is a technology soon to be demonstrated. A process evaluation of air-blown IGCC performed to estimate the plant heat rate, electrical output and potential emissions are described in this paper. A process model of an air-blown IGCC power system based on the Westinghouse 501F combustion turbine was developed to conduct the performance evaluation. Parametric studies were performed to develop an understanding of the power plant sensitivity to the major operating parameters and process options. Advanced hot fuel gas cleaning and conventional cold fuel gas cleaning options were both considered.


2021 ◽  
Vol 25 (2) ◽  
pp. 207-219
Author(s):  
A. D. Mekhryakov ◽  
A. N. Kudryashov ◽  
T. V. Koval

The study aims to improve the efficiency of waste utilisation from the coal-fired power industry based on an analysis of the dry-ash output unit operating at the Novo-Irkutsk Combined Heat and Power Plant, JSC “Irkutskenergo”. The unit was tested under various operating conditions of steam generating blocks following the standard methods adopted at the enterprise. The tests showed that the station steam generating block No. 3 (with a steam load of 409.2 t/h and an electrostatic precipitator efficiency of 90.46%) provided an ash supply efficiency of 7.10 t/h. When the ash is supplied from the steam generating block No. 4, operating at a steam load of 421.8 t/h and an electrostatic precipitator efficiency of 94.72%, the ash supply efficiency amounts to 9.19 t/h. Under the simultaneous operation of the steam generating blocks No. 3 and 4 at a steam load of 397.6 and 380.7 t/h, respectively, and an electrostatic precipitator efficiency of 90.46 and 94.72%, respectively, the unit efficiency was 14.23 t/h. As a result, limitations in the unit operation were identified. Thus, the airspeed in the pneumatic ash pipeline during ash transporting was 8.0-8.5 m/s, which facilitated the operation of the dry-ash output unit in a pulsed cycle. It was, therefore, recommended to increase the airspeed by accelerating the flow rate through the jet pump or by using a smaller diameter pipe. The conducted analysis showed that the efficiency of the dry-ash output unit depends mainly on the steam capacity of steam generating blocks, as well as on the flue gas cleaning efficiency in the steam generator electrostatic precipitators. The obtained results were used to determine the technical state, efficiency and reliability of the dry-ash output unit of the Novo-Irkutsk Combined Heat and Power Plant.


1980 ◽  
Author(s):  
J. W. Larson

The idea of a combined cycle power plant integrated with a coal gasification process has attracted broad interest in recent years. This interest is based on unique attributes of this concept which include potentially low pollutant emissions, low heat rate and competitive economics as compared to conventional steam plants with stack gas scrubbing. Results from a survey of technical literature containing performance and economic predictions have been compiled for comparison and evaluation of this new technique. These performance and economic results indicate good promise for near-term commercialization of an integrated gasification combined cycle power plant using current gas turbine firing temperatures. Also, these data show that advancements in turbine firing temperature are expected to provide sufficiently favorable economics for the concept to penetrate the market now held by conventional steam power plants.


Author(s):  
Michele Vascellari ◽  
Daniele Cocco ◽  
Giorgio Cau

Two power generation systems with pre-combustion CO2 capture fuelled with hydrogen from coal gasification are analyzed and compared from a thermodynamic and economic standpoint. The first solution, referred as Integrated Gasification Combined Cycle with CO2 Removal (IGCC-CR), is fuelled with hydrogen produced by the integrated gasification section. The second, referred as Integrated Gasification Hydrogen Cycle (IGHC), is based on the oxycombustion of hydrogen, producing steam that expands through an advanced high temperature steam turbine. The two H2 production sections are similar for both power plants, some minor modifications having been made to achieve better integration with the corresponding power sections. System performance is investigated using coherent assumptions to enable comparative analysis on the same basis. The plants have overall efficiencies of around 39.8% for IGCC-CR and 40.6% for IGHC, slightly lower than conventional IGCCs (without CO2 capture) with a CO2 removal efficiencies of 91% and 100% respectively. Lastly a preliminary economic analysis shows an increase in the cost of electricity compared to conventional IGCCs of about 44% for IGCC-CR and 50% IGHC.


2019 ◽  
Vol 105 ◽  
pp. 02017
Author(s):  
Olesya Aksenova ◽  
Evgenia Nikolaeva ◽  
Riccardo Paulman

The article seeks to examine the efficiency of applying means of mathematical processing and computer modeling of the work processes of gas cleaning facilities of power plants to optimize the process of planning and designing of future power plant in operation. A way of solution of the gas outbursts cleaning problem at the stage of designing measures for the development of waste processing systems through mathematical processing of expected volumes of gas outbursts and computer simulation of individual pieces of equipment and working areas as a whole is offered. The authors present the results of the processing of the projected technological processes and the gas outbursts cleaning facilities in terms of E-networks and using mathematical processing in the application Simulink, which allows to build a model of the device and to carry out calculations on the screen using the library of building blocks. A 3D model of the gas cleaning facilities, which allows to visualize the technological process and to compare it with theoretical calculations at the design stage of the future power plant and, if necessary, make changes to the project, has been created by means of computer modeling.


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