scholarly journals CO2 Capture from IGCC by Low-Temperature Synthesis Gas Separation

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 515
Author(s):  
David Berstad ◽  
Geir Skaugen ◽  
Simon Roussanaly ◽  
Rahul Anantharaman ◽  
Petter Nekså ◽  
...  

Capture conditions for CO2 vary substantially between industrial point sources. Depending on CO2 fraction and pressure level, different capture technologies will be required for cost- and energy-efficient decarbonisation. For decarbonisation of shifted synthesis gas from coal gasification, several studies have identified low-temperature CO2 capture by condensation and phase separation as an energy- and cost-efficient option. In the present work, a process design is proposed for low-temperature CO2 capture from an Integrated Gasification Combined Cycle (IGCC) power plant. Steady-state simulations were carried out and the performance of the overall process, as well as major process components, were investigated. For the baseline capture unit layout, delivering high-pressure CO2 at 150 bar, the net specific power requirement was estimated to 273 kJe/kgCO2, and an 85% CO2 capture ratio was obtained. The impact of 12 different process parameters was studied in a sensitivity analysis, the results of which show that compressor and expander efficiencies, as well as synthesis gas separation temperature, have the highest impact on power requirements. Modifying the process to producing cold liquid CO2 for ship transport resulted in 16% increase in net power requirements and is well suited for capturing CO2 for ship transport.

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.


Author(s):  
Arthur Cohn ◽  
Mark Waters

It is important that the requirements and cycle penalties related to the cooling of high temperature turbines be thoroughly understood and accurately factored into cycle analyses and power plant systems studies. Various methods used for the cooling of high temperature gas turbines are considered and cooling effectiveness curves established for each. These methods include convection, film and transpiration cooling using compressor bleed and/or discharge air. In addition, the effects of chilling the compressor discharge cooling gas are considered. Performance is developed to demonstrate the impact of the turbine cooling schemes on the heat rate and specific power of Combined–Cycle power plants.


Author(s):  
Frank Sander ◽  
Richard Carroni ◽  
Stefan Rofka ◽  
Eribert Benz

The rigorous reduction of greenhouse gas emissions in the upcoming decades is only achievable with contribution from the following strategies: production efficiency, demand reduction of energy and carbon dioxide (CO2) capture from fossil fueled power plants. Since fossil fueled power plants contribute largely to the overall global greenhouse gas emissions (> 25% [1]), it is worthwhile to capture and store the produced CO2 from those power generation processes. For natural-gas-fired power plants, post-combustion CO2 capture is the most mature technology for low emissions power plants. The capture of CO2 is achieved by chemical absorption of CO2 from the exhaust gas of the power plant. Compared to coal fired power plants, an advantage of applying CO2 capture to a natural-gas-fired combined cycle power plant (CCPP) is that the reference cycle (without CO2 capture) achieves a high net efficiency. This far outweighs the drawback of the lower CO2 concentration in the exhaust. Flue Gas Recirculation (FGR) means that flue gas after the HRSG is partially cooled down and then fed back to the GT intake. In this context FGR is beneficial because the concentration of CO2 can be significantly increased, the volumetric flow to the CO2 capture unit will be reduced, and the overall performance of the CCPP with CO2 capture is increased. In this work the impact of FGR on both the Gas Turbine (GT) and the Combined Cycle Power Plant (CCPP) is investigated and analyzed. In addition, the impact of FGR for a CCPP with and without CO2 capture is investigated. The fraction of flue gas that is recirculated back to the GT, need further to be cooled, before it is mixed with ambient air. Sensitivity studies on flue gas recirculation ratio and temperature are conducted. Both parameters affect the GT with respect to change in composition of working fluid, the relative humidity at the compressor inlet, and the impact on overall performance on both GT and CCPP. The conditions at the inlet of the compressor also determine how the GT and water/steam cycle are impacted separately due to FGR. For the combustion system the air/fuel-ratio (AFR) is an important parameter to show the impact of FGR on the combustion process. The AFR indicates how close the combustion process operates to stoichiometric (or technical) limit for complete combustion. The lower the AFR, the closer operates the combustion process to the stoichiometric limit. Furthermore, the impact on existing operational limitations and the operational behavior in general are investigated and discussed in context of an operation concept for a GT with FGR.


Author(s):  
Klaus Payrhuber ◽  
Robert M. Jones ◽  
Marcus H. Scholz

Over the next several decades, the power generation sector will face major landscape changes as CO2 management needs and hydrocarbon fuel options become limited. Uncontrolled carbon emissions from coal plants exceed natural gas fired alternatives by more than two to one due in large part to greater fuel carbon content and lower overall energy conversion efficiencies. In a carbon-constrained environment, power production from coal must realize improvements beyond incremental efficiency gains in order to have significant CO2 emissions reduction. Coal gasification and associated fuel gas process treatment units provide the mechanisms inherently needed to effectively separate carbon components on a “pre-combustion” basis, leaving essentially carbon free hydrogen fuel available for combustion within the combined cycle power plant. Gas turbines will play a significant role in meeting this generation challenge, not only from a fuel flexibility perspective, but also in the area of CO2 reduction where gas turbines will likely become the primary hydrogen energy conversion unit for the foreseeable future. Worldwide, GE gas turbines continue to demonstrate their proven, reliable performance on hydrogen bearing fuels, including installations with up to 95% hydrogen by volume. As the focus on pre-combustion carbon capture continues to grow, never has this experience with high hydrogen fuels been more relevant. Furthermore, GE continues to develop combustion designs to extend this experience to advanced gas turbine platforms, including F-class units operating on synthesis gas. The ever-present focus on efficiency improvement and emissions reduction, combined with improved gasification processes, will require future advanced combustion system designs that can achieve low emissions at higher firing temperatures with minimal to no dilution for NOx abatement. This paper discusses the challenge of low CO2 producing fuel for advanced gas turbines, firing hydrogen rich synthesis gas, in terms of gas turbine fuel and accessory system design.


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 193 ◽  
pp. 304-316 ◽  
Author(s):  
Yusuke Furusawa ◽  
Haruka Taguchi ◽  
Siti Norazian Ismail ◽  
Sivasakthivel Thangavel ◽  
Koichi Matsuoka ◽  
...  

Author(s):  
Ram G. Narula ◽  
Harvey Wen

Coal is an abundant, widespread, cheap energy source and contributes to 39% of the world’s electric power generation. Coal releases large amounts of carbon dioxide (CO2), which is believed to play a major role in global warming and climate change. To de-carbonize power generation, three distinct carbon capture technologies are in varying stages of development. These include pre-combustion carbon capture through the use of integrated coal gasification combined cycle (IGCC), post-combustion carbon capture from a pulverized-coal (PC)-fired power plant flue gas using monoethanolamine (MEA) or ammonia (NH3), and oxy-combustion technology. In the latter technology, oxygen is first separated from nitrogen in an air separator unit and used for combustion of coal in a conventional PC boiler. With oxy-combustion technology, the resulting flue gas is predominantly CO2, which makes CO2 capture easier than in the PC-MEA case. This paper discusses the development status as well as the advantages, limitations, performance and economics of each technology in regard to the capture and non-capture cases.


2007 ◽  
Vol 26-28 ◽  
pp. 267-270
Author(s):  
Woo Teck Kwon ◽  
Soo Ryong Kim ◽  
Eun Bi Kim ◽  
Seong Youl Bae ◽  
Y. Kim

Due to the need for CO2 sequestration associated with H2 production from fossil fuels, zeolite membrane are very promising due to their low cost, high stability and high permeance. Recently, the faujasite(FAU), the silica/aluminophophate(SAPO-4) framework family of zeolite have been studied for CO2 gas separation. In our study, ZSM-5 membrane was prepared on the porous alumina support using a hydrothermal technique. The thickness of zeolite membrane was controlled by the hydrothermal reaction time and temperature. The prepared zeolite membranes were characterized with SEM and thin film XRD. The hydrogen permeability and selectivity toward carbon dioxide gas were 0.6x 10-6 mole/m2.s.pa and 3.16, respectively. The hydrogen selective zeolite membranes show promising application in hydrogen separation from coal gasification such as Integrated Gasification Combined Cycle (IGCC).


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