Production & Supply Chain
Hydrogen Production in Methane Decomposition Reactor Using Solar Thermal Energy
Nov 2021
Publication
This study investigates the decomposition of methane using solar thermal energy as a heat source. Instead of the direct thermal decomposition of the methane at a temperature of 1200 ◦C or higher a catalyst coated with carbon black on a metal foam was used to lower the temperature and activation energy required for the reaction and to increase the yield. To supply solar heat during the reaction a reactor suitable for a solar concentrating system was developed. In this process a direct heating type reactor with quartz was initially applied and a number of problems were identified. An indirect heating type reactor with an insulated cavity and a rotating part was subsequently developed followed by a thermal barrier coating application. Methane decomposition experiments were conducted in a 40 kW solar furnace at the Korea Institute of Energy Research. Conversion rates of 96.7% and 82.6% were achieved when the methane flow rate was 20 L/min and 40 L/min respectively.
Water Electrolysis for the Production of Hydrogen to Be Employed in the Ironmaking and Steelmaking Industry
Nov 2021
Publication
The way to decarbonization will be characterized by the huge production of hydrogen through sustainable routes. Thus the basic production way is water electrolysis sustained by renewable energy sources allowing for obtaining “green hydrogen”. The present paper reviews the main available technologies for the water electrolysis finalized to the hydrogen production. We describe the fundamental of water electrolysis and the problems related to purification and/or desalinization of water before electrolysis. As a matter of fact we describe the energy efficiency issues with particular attention to the potential application in the steel industry. The fundamental aspects related to the choice of high-temperature or low-temperature technologies are analyzed.
Study of the Effect of Addition of Hydrogen to Natural Gas on Diaphragm Gas Meters
Jun 2020
Publication
Power-to-gas technology plays a key role in the success of the energy transformation. This paper addresses issues related to the legal and technical regulations specifying the rules for adding hydrogen to the natural gas network. The main issue reviewed is the effects of the addition of hydrogen to natural gas on the durability of diaphragm gas meters. The possibility of adding hydrogen to the gas network requires confirmation of whether within the expected hydrogen concentrations long-term operation of gas meters will be ensured without compromising their metrological properties and operational safety. Methods for testing the durability of gas meters applied at test benches and sample results of durability tests of gas meters are presented. Based on these results a metrological and statistical analysis was carried out to establish whether the addition of hydrogen affects the durability of gas meters over time. The most important conclusion resulting from the conducted study indicates that for the tested gas meter specimens there was no significant metrological difference between the obtained changes of errors of indications after testing the durability of gas meters with varying hydrogen content (from 0% to 15%).
Hydrogen Production: State of Technology
May 2020
Publication
Presently hydrogen is for ~50% produced by steam reforming of natural gas – a process leading to significant emissions of greenhouse gas (GHG). About 30% is produced from oil/naphtha reforming and from refinery/chemical industry off-gases. The remaining capacity is covered for 18% from coal gasification 3.9% from water electrolysis and 0.1% from other sources. In the foreseen future hydrogen economy green hydrogen production methods will need to supply hydrogen to be used directly as fuel or to generate synthetic fuels to produce ammonia and other fertilizers (viz. urea) to upgrade heavy oils (like oil sands) and to produce other chemicals. There are several ways to produce H2 each with limitations and potential such as steam reforming electrolysis thermal and thermo-chemical water splitting dark and photonic fermentation; gasification and catalytic decomposition of methanol. The paper reviews the fundamentals and potential of these alternative process routes. Both thermo-chemical water splitting and fermentation are marked as having a long term but high "green" potential.
Optimal Operation of the Hydrogen-based Energy Management System with P2X Demand Response and Ammonia Plant
Jul 2021
Publication
Hydrogen production is the key in utilizing an excess renewable energy. Many studies and projects looked at the energy management systems (EMSs) that allow to couple hydrogen production with renewable generation. In the majority of these studies however hydrogen demand is either produced for powering fuel cells or sold to the external hydrogen market. Hydrogen demand from actual industrial plants is rarely considered. In this paper we propose an EMS based on the industrial cluster of GreenLab Skive (GLS) that can minimize the system’s operational cost or maximize its green hydrogen production. EMS utilizes a conventional and P2X demand response (DR) flexibility from electrolysis plant hydrogen storage tank electric battery and hydrogen-consuming plants to design the optimal schedule with maximized benefits. A potential addition to the existing components at GLS - an ammonia plant is modelled to identify its P2X potential and assess the economic viability of its construction. The results show a potential reduction of 51.5–61.6% for the total operational cost of the system and an increase of the share of green hydrogen by 10.4–37.6% due to EMS operation.
Production of H2-rich Syngas from Excavated Landfill Waste through Steam Co-gasification with Biochar
Jun 2020
Publication
Gasification of excavated landfill waste is one of the promising options to improve the added-value chain during remediation of problematic old landfill sites. Steam gasification is considered as a favorable route to convert landfill waste into H2-rich syngas. Co-gasification of such a poor quality landfill waste with biochar or biomass would be beneficial to enhance the H2 concentration in the syngas as well as to improve the gasification performance. In this work steam co-gasification of landfill waste with biochar or biomass was carried out in a lab-scale reactor. The effect of the fuel blending ratio was investigated by varying the auxiliary fuel content in the range of 15e35 wt%. Moreover co-gasification tests were carried out at temperatures between 800 and 1000°C. The results indicate that adding either biomass or biochar enhances the H2 yield where the latter accounts for the syngas with the highest H2 concentration. At 800°C the addition of 35 wt% biochar can enhance the H2 concentration from 38 to 54 vol% and lowering the tar yield from 0.050 to 0.014 g/g-fuel-daf. No apparent synergetic effect was observed in the case of biomass co-gasification which might cause by the high Si content of landfill waste. In contrast the H2 production increases non-linearly with the biochar share in the fuel which indicates that a significant synergetic effect occurs during co-gasification due to the reforming of tar over biochar. Increasing the temperature of biochar co-gasification from 800 to 1000°C elevates the H2 concentration but decreases the H2/CO ratio and increases the tar yield. Furthermore the addition of biochar also enhances the gasification efficiency as indicated by increased values of the energy yield ratio.
Economic Conditions for Developing Hydrogen Production Based on Coal Gasification with Carbon Capture and Storage in Poland
Sep 2020
Publication
This study documents the results of economic assessment concerning four variants of coal gasification to hydrogen in a shell reactor. That assessment has been made using discounting methods (NPV: net present value IRR: internal rate of return) as well as indicators based on a free cash flow to firm (FCFF) approach. Additionally sensitivity analysis has been carried out along with scenario analysis in current market conditions concerning prices of hard coal lignite hydrogen and CO2 allowances as well as capital expenditures and costs related to carbon capture and storage (CCS) systems. Based on NPV results a negative economic assessment has been obtained for all the analyzed variants varying within the range of EUR −903 to −142 million although the variants based on hard coal achieved a positive IRR (5.1–5.7%) but lower than the assumed discount rates. In Polish conditions the gasification of lignite seems to be unprofitable in the assumed scale of total investment outlays and the current price of coal feedstock. The sensitivity analyses indicate that at least a 20% increase of hydrogen price would be required or a similar reduction of capital expenditures (CAPEX) and costs of operation for the best variant to make NPV positive. Analyses have also indicated that on the economic basis only the prices of CO2 allowances exceeding EUR 40/Mg (EUR 52/Mg for lignite) would generate savings due to the availability of CCS systems.
Goal and Scope in Life Cycle Sustainability Analysis: The Case of Hydrogen Production from Biomass
Aug 2014
Publication
The framework for life cycle sustainability analysis (LCSA) developed within the project CALCAS (Co-ordination Action for innovation in Life-Cycle Analysis for Sustainability) is introducing a truly integrated approach for sustainability studies. However it needs to be further conceptually refined and to be made operational. In particular one of the gaps still hindering the adoption of integrated analytic tools for sustainability studies is the lack of a clear link between the goal and scope definition and the modeling phase. This paper presents an approach to structure the goal and scope phase of LCSA so as to identify the relevant mechanisms to be further detailed and analyzed in the modeling phase. The approach is illustrated with an on-going study on a new technology for the production of high purity hydrogen from biomass to be used in automotive fuel cells.
Effects of CO2 sequestration on lipid and biomass productivity in microalgal biomass production
Mar 2017
Publication
The study is focused on the technology and manipulation of production strategies for the cultivation of biomass from four strains of microalgae. Species of microalgae studied are: Chlorella vulgaris Dunaliella Scenedesmus quadricauda and Synechococcus spp. The effects of the rate and amount of CO2 removal from the atmosphere and sequestration with dissolved oxygen on lipid production from accumulated biomass were studied. Also the rate of sequestration of both total and dissolved carbon was investigated. Daily measurements of total organic and inorganic carbon sequestrated optical densities proximate analysis and kinetic parameters of the growing and cultivated microalga were monitored and carried out during the two phases of cultivation: dark and light phases. The values of maximum rate of carbon (IV) oxide removed rmax varied from 11.73 mg L -1 min -1 to 18.84 mg L -1 min -1 from Chlorella vulgaris to Synechoccocus spp. Important parameters such as biomass productivity maximum pH values obtained at cultivation lipid content of the produced biomass and the hydraulic detection time for all four strains of microalgae were considered and presented in comparison and with their individual and collective effects. The ratios of the rate of CO2 absorption constant and the constant for the CO2 desorption rate (k1/k2) occurred highest in Dunaliella suggesting that with a high uptake of CO2 the algal strain is more effective in CO2 CO2 sequestration. The best biomass producer in this study was the C. vulgaris (Xmax = 5400 mg L-1 and Px = 35.1 mg L h -1) where biomass productivity is Px and the maximum cellular concentration is Xmax. C. vulgaris has the highest lipids productivity of 27% while Synechoccocus has the least (11.72%). In general biomass productivity may be inversely related; this fact may be explained by greater metabolic involvement of lipid biosynthesis. This pioneer study may be advanced further to developing models for strategic manipulation and optimisation approach in micro algal biomass cultivation.
Valorization and Sequestration of Hydrogen Gas from Biomass Combustion in Solid Waste Incineration NaOH Oxides of Carbon Entrapment Model (SWI-NaOH-OCE Model)
Dec 2019
Publication
The valorization of biomass-based solid wastes for both geotechnical engineering purposes and energy needs has been reviewed to achieve eco-friendly eco-efficient and sustainable engineering and reengineering of civil engineering materials and structures. The objective of this work was to review the procedure developed by SWI-NaOH-OCE Model for the valorization of biomass through controlled direct combustion and the sequestration of hydrogen gas for energy needs. The incineration model gave a lead to the sequestration of emissions released during the direct combustion of biomass and the subsequent entrapment of oxides of carbon and the eventual release of abundant hydrogen gas in the entrapment jar. The generation of geomaterials ash for the purpose of soil stabilization concrete and asphalt modification has encouraged greenhouse emissions but eventually the technology that has been put in place has made it possible to manage and extract these emissions for energy needs. The contribution from researchers has shown that hydrogen sequestration from other sources requires high amount of energy because of the lower energy states of the compounds undergoing thermal decomposition. But this work has presented a more efficient approach to release hydrogen gas which can easily be extracted and stored to meet the energy needs of the future as fuel cell batteries to power vehicles mobile devices robotic systems etc. More so the development of MXene as an exfoliated two-dimensional nanosheets with permeability and filtration selectivity properties which are connected to its chemical composition and structure used in hydrogen gas extraction and separation from its molecular combination has presented an efficient procedure for the production and management of hydrogen gas for energy purposes.
A Critical Time for UK Energy Policy What Must be Done Now to Deliver the UK’s Future Energy System: A Report for the Council for Science and Technology
Oct 2015
Publication
Time is rapidly running out to make the crucial planning decisions and secure investment to keep the UK on track to deliver a reliable affordable and decarbonised energy system to meet future emissions regulation enshrined in the 2008 Climate Change Act according to a report published today by the Royal Academy of Engineering.
Prepared for the Prime Minister's Council for Science and Technology A critical time for UK energy policy details the actions needed now to create a secure and affordable low carbon energy system for 2030 and beyond.
The study looks at the future evolution of the UK’s energy system in the short to medium term. It considers how the system is expected to develop across a range of possible trajectories identified through modelling and scenarios.
The following actions for government are identified as a matter of urgency:
The report notes that the addition of shale gas or tight oil is unlikely to have a major impact on the evolution of the UK's energy system as we already have secure and diverse supplies of hydrocarbons from multiple sources.
Dr David Clarke FREng who led the group that produced the report says: “Updating the UK energy system to meet the ‘trilemma’ of decarbonisation security and affordability is a massive undertaking. Meeting national targets affordably requires substantial decarbonisation of the electricity system by 2030 through a mix of nuclear power CCS and renewables with gas generation for balancing. Beyond 2030 we must then largely decarbonise heat and transport potentially through electrification but also using other options such as hydrogen and biofuels. We also need to adapt our transmission and distribution networks to become ‘smarter’”.
"Failure to plan the development of the whole energy system carefully will result at best in huge increases in the cost of delivery or at worst a failure to deliver. Substantial investment is needed and current investment capacity is fragile. For example in the last month projects like Carlton’s new Trafford CCGT plant have announced further financing delays and the hoped-for investment by Drax in the White Rose CCS demonstrator has been withdrawn. The UK has also dropped four places to 11th in EY’s renewable energy country attractiveness index.”
Link to document download on Royal Society Website
Prepared for the Prime Minister's Council for Science and Technology A critical time for UK energy policy details the actions needed now to create a secure and affordable low carbon energy system for 2030 and beyond.
The study looks at the future evolution of the UK’s energy system in the short to medium term. It considers how the system is expected to develop across a range of possible trajectories identified through modelling and scenarios.
The following actions for government are identified as a matter of urgency:
- enable local or regional whole-system large scale pilot projects to establish real-world examples of how the future system will work. These must move beyond current single technology demonstrators and include all aspects of the energy systems along with consumer behaviour and financial mechanisms
- drive forward new capacity in the three main low carbon electricity generating technologies: nuclear carbon capture and storage (CCS) and offshore wind
- develop policies to accelerate demand reduction especially in domestic heating and introduce smarter demand management
- clarify and stabilise market mechanisms and incentives in order to give industry the confidence to invest.
The report notes that the addition of shale gas or tight oil is unlikely to have a major impact on the evolution of the UK's energy system as we already have secure and diverse supplies of hydrocarbons from multiple sources.
Dr David Clarke FREng who led the group that produced the report says: “Updating the UK energy system to meet the ‘trilemma’ of decarbonisation security and affordability is a massive undertaking. Meeting national targets affordably requires substantial decarbonisation of the electricity system by 2030 through a mix of nuclear power CCS and renewables with gas generation for balancing. Beyond 2030 we must then largely decarbonise heat and transport potentially through electrification but also using other options such as hydrogen and biofuels. We also need to adapt our transmission and distribution networks to become ‘smarter’”.
"Failure to plan the development of the whole energy system carefully will result at best in huge increases in the cost of delivery or at worst a failure to deliver. Substantial investment is needed and current investment capacity is fragile. For example in the last month projects like Carlton’s new Trafford CCGT plant have announced further financing delays and the hoped-for investment by Drax in the White Rose CCS demonstrator has been withdrawn. The UK has also dropped four places to 11th in EY’s renewable energy country attractiveness index.”
Link to document download on Royal Society Website
Renewable Hydrogen Production from Butanol: A Review
Dec 2017
Publication
Hydrogen production from butanol is a promising alternative when it is obtained from bio-butanol or bio-oil due to the higher hydrogen content compared to other oxygenates such as methanol ethanol or propanol. Catalysts and operating conditions play a crucial role in hydrogen production. Ni and Rh are metals mainly used for butanol steam reforming oxidative steam reforming and partial oxidation. Additives such as Cu can improve catalytic activity in many folds. Moreover support–metal interaction and catalyst preparation technique also play a decisive role in the stability and hydrogen production capacity of catalyst. Steam reforming technique as an option is more frequently researched due to higher hydrogen production capability in comparison to other thermochemical techniques despite its endothermic nature. The use of the oxidative steam reforming and partial oxidation has the advantages of requiring less energy and longer stability of catalysts. However the hydrogen yield is less. This article brings together and examines the latest research on hydrogen production from butanol via steam reforming oxidative steam reforming and partial oxidation reactions. In addition the review examines a few thermodynamic studies based on sorption-enhanced steam reforming and dry reforming where there is potential for hydrogen extraction.
Hydrocarbon Production by Continuous Hydrodeoxygenation of Liquid Phase Pyrolysis Oil with Biogenous Hydrogen Rich Synthesis Gas
Feb 2019
Publication
This paper presents a beneficial combination of biomass gasification and pyrolysis oil hydrodeoxygenation for advanced biofuel production. Hydrogen for hydrodeoxygenation (HDO) of liquid phase pyrolysis oil (LPP oil) was generated by gasification of softwood. The process merges dual fluidized bed (DFB) steam gasification which produces a hydrogen rich product gas and the HDO of LPP oil. Synthesis gas was used directly without further cleaning and upgrading by making use of the water gas-shift (WGS) reaction. The water needed for the water gas-shift reaction was provided by LPP oil. HDO was successfully performed in a lab scale over 36 h time on stream (TOS). Competing reactions like the Boudouard reaction and Sabatier reaction were not observed. Product quality was close to Diesel fuel specification according to EN 590 with a carbon content of 85.4 w% and a residual water content of 0.28 w%. The water-gas shift reaction was confirmed by CO/CO2-balance high water consumption and 28% less hydrogen consumption during HDO.
Aqueous Phase Reforming in a Microchannel Reactor: The Effect of Mass Transfer on Hydrogen Selectivity
Aug 2013
Publication
Aqueous phase reforming of sorbitol was carried out in a 1.7 m long 320 mm ID microchannel reactor with a 5 mm Pt-based washcoated catalyst layer combined with nitrogen stripping. The performance of this microchannel reactor is correlated to the mass transfer properties reaction kinetics hydrogen selectivity and product distribution. Mass transfer does not affect the rate of sorbitol consumption which is limited by the kinetics of the reforming reaction. Mass transfer significantly affects the hydrogen selectivity and the product distribution. The rapid consumption of hydrogen in side reactions at the catalyst surface is prevented by a fast mass transfer of hydrogen from the catalyst site to the gas phase in the microchannel reactor. This results in a decrease of the concentration of hydrogen at the catalyst surface which was found to enhance the desired reforming reaction rate at the expense of the undesired hydrogen consuming reactions. Compared to a fixed bed reactor the selectivity to hydrogen in the microchannel reactor was increased by a factor of 2. The yield of side products (mainly C3 and heavier hydrodeoxygenated species) was suppressed while the yield of hydrogen was increased from 1.4 to 4 moles per mole of sorbitol fed.
Life Cycle Assessments on Battery Electric Vehicles and Electrolytic Hydrogen: The Need for Calculation Rules and Better Databases on Electricity
May 2021
Publication
LCAs of electric cars and electrolytic hydrogen production are governed by the consumption of electricity. Therefore LCA benchmarking is prone to choices on electricity data. There are four issues: (1) leading Life Cycle Impact (LCI) databases suffer from inconvenient uncertainties and inaccuracies (2) electricity mix in countries is rapidly changing year after year (3) the electricity mix is strongly fluctuating on an hourly and daily basis which requires time-based allocation approaches and (4) how to deal with nuclear power in benchmarking. This analysis shows that: (a) the differences of the GHG emissions of the country production mix in leading databases are rather high (30%) (b) in LCA a distinction must be made between bundled and unbundled registered electricity certificates (RECs) and guarantees of origin (GOs); the residual mix should not be applied in LCA because of its huge inaccuracy (c) time-based allocation rules for renewables are required to cope with periods of overproduction (d) benchmarking of electricity is highly affected by the choice of midpoints and/or endpoint systems and (e) there is an urgent need for a new LCI database based on measured emission data continuously kept up-to-date transparent and open access.
Continuous Hydrogen Regeneration Through the Oxygen Vacancy Control of Metal Oxides Using Microwave Irradiation
Nov 2018
Publication
The amount of hydrogen gas generated from metal oxide materials based on a thermochemical water-splitting method gradually reduces as the surface of the metal oxide oxidizes during the hydrogen generation process. To regenerate hydrogen the oxygen reduction process of a metal oxide at high temperatures (1000–2500 °C) is generally required. In this study to overcome the problem of an energy efficiency imbalance in which the required energy of the oxygen reduction process for hydrogen regeneration is higher than the generated hydrogen energy we investigated the possibility of the oxygen reduction of a metal oxide with a low energy using microwave irradiation. For this purpose a macroporous nickel-oxide structure was used as a metal oxide catalyst to generate hydrogen gas and the oxidized surface of the macroporous nickel-oxide structure could be reduced by microwave irradiation. Through this oxidation reduction process ∼750 μmol g−1 of hydrogen gas could be continuously regenerated. In this way it is expected that oxygen-enriched metal oxide materials can be efficiently reduced by microwave irradiation with a low power consumption of <∼4% compared to conventional high-temperature heat treatment and thus can be used for efficient hydrogen generation and regeneration processes in the future.
Improving the Efficiency of PEM Electrolyzers through Membrane-Specific Pressure Optimization
Feb 2020
Publication
Hydrogen produced in a polymer electrolyte membrane (PEM) electrolyzer must be stored under high pressure. It is discussed whether the gas should be compressed in subsequent gas compressors or by the electrolyzer. While gas compressor stages can be reduced in the case of electrochemical compression safety problems arise for thin membranes due to the undesired permeation of hydrogen across the membrane to the oxygen side forming an explosive gas. In this study a PEM system is modeled to evaluate the membrane-specific total system efficiency. The optimum efficiency is given depending on the external heat requirement permeation cell pressure current density and membrane thickness. It shows that the heat requirement and hydrogen permeation dominate the maximum efficiency below 1.6 V while above the cell polarization is decisive. In addition a pressure-optimized cell operation is introduced by which the optimum cathode pressure is set as a function of current density and membrane thickness. This approach indicates that thin membranes do not provide increased safety issues compared to thick membranes. However operating an N212-based system instead of an N117-based one can generate twice the amount of hydrogen at the same system efficiency while only one compressor stage must be added.
Potential and Economic Analysis of Solar-to-Hydrogen Production in the Sultanate of Oman
Aug 2021
Publication
Hydrogen production using renewable power is becoming an essential pillar for future sustainable energy sector development worldwide. The Sultanate of Oman is presently integrating renewable power generations with a large share of solar photovoltaic (PV) systems. The possibility of using the solar potential of the Sultanate can increase energy security and contribute to the development of the sustainable energy sector not only for the country but also for the international community. This study presents the hydrogen production potential using solar resources available in the Sultanate. About 15 locations throughout the Sultanate are considered to assess the hydrogen production opportunity using a solar PV system. A rank of merit order of the locations for producing hydrogen is identified. It reveals that Thumrait and Marmul are the most suitable locations whereas Sur is the least qualified. This study also assesses the economic feasibility of hydrogen production which shows that the levelized cost of hydrogen (LCOH) in the most suitable site Thumrait is 6.31 USD/kg. The LCOH in the least convenient location Sur is 7.32 USD/kg. Finally a sensitivity analysis is performed to reveal the most significant influential factor affecting the future’s green hydrogen production cost. The findings indicate that green hydrogen production using solar power in the Sultanate is promising and the LCOH is consistent with other studies worldwide.
End of Life of Fuel Cells and Hydrogen Products: From Technologies to Strategies
Feb 2019
Publication
End-of-Life (EoL) technologies and strategies are needed to support the deployment of fuel cells and hydrogen (FCH) products. This article explores current and novel EoL technologies to recover valuable materials from the stacks of proton exchange membrane fuel cells and water electrolysers alkaline water electrolysers and solid oxide fuel cells. Current EoL technologies are mainly based on hydrometallurgical and pyro-hydrometallurgical methods for the recovery of noble metals while novel methods attempt to recover additional materials through efficient safe and cost-competitive pathways. Strengths weaknesses opportunities and threats of the reviewed EoL technologies are identified under techno-economic environmental and regulatory aspects. Beyond technologies strategies for the EoL of FCH stacks are defined mainly based on the role of manufacturers and recovery centres in the short- mid- and long-term. In this regard a dual role manufacturer/recovery centre would characterise long-term scenarios within a potential context of a well-established hydrogen economy.
Integration of Gas Switching Combustion and Membrane Reactors for Exceeding 50% Efficiency in Flexible IGCC Plants with Near-zero CO2 Emissions
Jul 2020
Publication
Thermal power plants face substantial challenges to remain competitive in energy systems with high shares of variable renewables especially inflexible integrated gasification combined cycles (IGCC). This study addresses this challenge through the integration of Gas Switching Combustion (GSC) and Membrane Assisted Water Gas Shift (MAWGS) reactors in an IGCC plant for flexible electricity and/or H2 production with inherent CO2 capture. When electricity prices are high H2 from the MAWGS reactor is used for added firing after the GSC reactors to reach the high turbine inlet temperature of the H-class gas turbine. In periods of low electricity prices the turbine operates at 10% of its rated power to satisfy the internal electricity demand while a large portion of the syngas heating value is extracted as H2 in the MAWGS reactor and sold to the market. This product flexibility allows the inflexible process units such as gasification gas treating air separation unit and CO2 compression transport and storage to operate continuously while the plant supplies variable power output. Two configurations of the GSC-MAWGS plant are presented. The base configuration achieves 47.2% electric efficiency and 56.6% equivalent hydrogen production efficiency with 94.8–95.6% CO2 capture. An advanced scheme using the GSC reduction gases for coal-water slurry preheating and pre-gasification reached an electric efficiency of 50.3% hydrogen efficiency of 62.4% and CO2 capture ratio of 98.1–99.5%. The efficiency is 8.4%-points higher than the pre-combustion CO2 capture benchmark and only 1.9%-points below the unabated IGCC benchmark.
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