Thermochemical Hydrogen Production Research Articles

Techno-economic analysis of a solar thermochemical cycle-based direct coal liquefaction system for low-carbon oil production

Direct coal liquefaction turns solid coal into transportable liquid fuel with a high energy conversion efficiency of nearly 60%. However, the hydrogen used in the direct coal liquefaction process mainly comes from coal gasification units, and gasification coal consumption accounts for about 30% of the total coal consumption. The authors of this article have proposed a solar thermochemical cycle-based direct coal liquefaction system and conducted a corresponding thermodynamic analysis. In this work, the economic feasibility, environmental impact, and the influence of key factors (coal price, oil price, carbon tax) for the industrial-scale low-carbon oil production system are analyzed. Compared with the traditional direct coal liquefaction system, the total coal consumption of the new system is reduced by ∼40%. Under low carbon constraints, the economics of the new system is comparable to that of the traditional one with a lower solar thermochemical hydrogen production cost (<13–16 yuan/kg H2). With the help of the solar thermochemical hydrogen production process, CO2 emissions of the new system can be reduced by 63%. Moreover, the solar thermochemical cycle could generate additional pure oxygen and profits. The methodology and results can provide important references for coal-to-liquid technology with high efficiency and low carbon emissions.

Thermodynamic modeling of sulfuric acid decomposer integrated with 1 MW tubular SOFC stack for sulfur-based thermochemical hydrogen production

This study developed a thermodynamic model of a set of sulfuric acid decomposers for thermochemical hydrogen production. It was integrated with a 1 MW tubular-type solid oxide fuel cell (SOFC) stack. With the model, we evaluated the feasibility of the combined production of electric power, heat, and sulfur dioxide for thermochemical H2 production. The integrated reactor model consists of three parts: i) SOFC submodel, ii) sulfuric acid decomposition (SAD) submodel, and iii) sulfur trioxide decomposition (STD) submodel with the catalysts Pt/γAl2O3 and WX-1. The efficiency of the integrated system was evaluated at a low-pressure range by polarization and efficiency curves for the SOFC, as well as pinch analysis for the SAD. The highest SOFC efficiency and SO2 production were achieved at 1.25 bar, whereas the lowest fuel consumption and heat demand for SO2 production were achieved at 3.0 bar. Furthermore, WX-1 performed better in the high-temperature range, whereas Pt/γAl2O3 performed better than WX-1 under low-temperature conditions. The Pt-supported catalyst could achieve SO3 conversion of 66% and SO2 yield of 57% at a gas temperature of 1025 K using the proposed integrated reactor design.

Reduction Thermodynamics of Sr1−xCexMnO3 and CexSr2−xMnO4 Perovskites for Solar Thermochemical Hydrogen Production

Herein, the compositional families Sr1−xCexMnO3 (SCMX, X = 100x, x = 0.10, 0.20, and 0.30) and CexSr2−xMnO4 (CSMX, X = 100x, x = 0.10, 0.20, and 0.30) are studied to determine the effects of perovskite structure and cerium content on thermal reduction thermodynamics and the resulting impact on solar thermochemical hydrogen production (STCH). Relying on thermogravimetric results from oxygen nonstoichiometry experiments, fits for various thermodynamic quantities are produced, including defect‐reaction specific enthalpy ( and entropy (), as well as the δ‐dependent standard partial molar enthalpy, , and entropy , of oxygen as a function of composition within these two perovskite families. The results of this thermodynamic study are also discussed in the context of structure and cerium dopant level. Experimental hydrogen production results show that the SCM family produces slightly larger amounts of hydrogen per mole of oxide compared with the CSM family under similar reduction and oxidation temperature conditions, however, a direct correlation between structure, cerium content, and water‐splitting capacity could not be discerned.

Double-Site Substitution of Ce into (Ba, Sr)MnO3 Perovskites for Solar Thermochemical Hydrogen Production

Solar thermochemical hydrogen production (STCH) is a renewable alternative to hydrogen produced using fossil fuels. While serial bulk experimental methods can accurately measure STCH performance, screening chemically complex materials systems for new promising candidates is more challenging. Here we identify double-site Ce-substituted (Ba,Sr)MnO3 oxide perovskites as promising STCH candidates using a combination of bulk synthesis and high-throughput thin film experiments. The Ce substitution on the B-site in 10H-BaMnO3 and on the A-site in 4P-SrMnO3 lead to 2-3x higher hydrogen production compared to CeO2, but these bulk single-site substituted perovskites suffer from incomplete reoxidation. Double-site Ce substitution on both A- and B-site in (Ba,Sr)MnO3 thin films increases Ce solubility and extends the stability of 10H and 4P structures, which is promising for their thermochemical reversibility. This study demonstrates a high-throughput experimental method for screening complex oxide materials for STCH applications.

A framework for a hydrogen economy

Arun Majumdar is the Jay Precourt Professor at Stanford University, a faculty in the Department of Mechanical Engineering, and a Senior Fellow and former Director of the Precourt Institute for Energy. He served in the Obama administration as the Founding Director of the US Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E) (2009–2012), as the Acting Undersecretary for Energy (2011–2012), and as the Vice Chair of the Secretary of Energy Advisory Board (2014–2017). Dr. Majumdar is a member of the US National Academy of Sciences, US National Academy of Engineering, and the American Academy of Arts and Sciences. John Deutch is an emeritus Institute Professor at MIT. He has served as Chairman of the Department of Chemistry, Dean of Science, and Provost. In the Carter administration, he served as Director of Energy Research (1977–1979), Acting Assistant Secretary for Energy Technology (1979), and Undersecretary (1979–1980) in the US Department of Energy. He has been a member of the President's Nuclear Safety Oversight Committee (1980–1981), the White House Science Council (1985–1989), the President's Committee of Advisors on Science and Technology (1997–2001), and the Secretary of the Energy Advisory Board (2008–2017). He has published widely on the technical and policy aspects of energy and the environment. Ravi Prasher is an Adjunct Professor at the University of California, Berkeley. He has more than 20 years of experience in working in R&D in large industry, startup, government, and academia. He was one of the first program directors at ARPA-E in the US Department of Energy. Prasher has published more than 100 papers on thermal energy science and technology and holds more than 30 patents. At UC Berkeley, he teaches undergraduate and graduate courses on thermal science and supervises multiple PhD students on various research topics, including thermochemical production of carbon-free hydrogen. Tom Griffin specializes in identifying high-impact technology investment opportunities in the manufacturing sector for Breakthrough Energy Ventures. He has over 25 years of industrial experience in applied technology development and deployment, including contributions over a wide range of energy and environmental sectors. He served as CTO at both Edeniq and Pennsylvania Sustainable Technologies (where was also co-founder), pursuing capabilities and applications in biofuels and catalytic fuel upgrading. Griffin was an officer in the US Nuclear Navy, directing operations of shipboard propulsion facilities. He holds SB, SM, and PhD degrees in Chemical Engineering from MIT and has authored or co-authored several granted patents.

Investigation of a hybrid solar thermochemical water-splitting hydrogen production cycle and coal-fueled molten carbonate fuel cell power plant

Increasing electricity demand in the world’s energy portfolio and the focus on reducing carbon emission footprints has led to broad research into flexible and efficient energy conversion systems. The integration of various energy conversion systems is an efficient approach to meet sustainable energy technologies’ demand in the future. In this study, a brainchild integration process of the solar thermochemical water-splitting hydrogen production cycle and coal-fueled molten carbonate fuel cell coupled with a gas turbine is proposed, modeled, and simulated in AspenTech v9.1. The Zinc/Zinc-oxide thermochemical cycle directly utilizes the solar high-temperature reactor thereby avoiding the need for non-renewable power, thus increasing the efficiency of the system. The molten carbonate fuel cell feeds on the syngas produced by the coal gasification and the oxygen and hydrogen of the thermochemical cycle. The heat of the fuel cell is further exploited by a gas turbine. A sensitivity analysis is conducted to appraise cardinal parameters on system performance indicating the fuel cell pressure, voltage, and current density as the most influential parameters. The concentrated solar power provides 5.88 MW of heat for the thermochemical cycle encompassing 434 parabolic dishes. The molten carbonate fuel cell has a 63% and 61% LHV and HHV efficiency, respectively, and the system has a total efficiency of approximately 85%, producing 13.63 MW of electricity.

Operational Limits of Redox Metal Oxides Performing Thermochemical Water Splitting

Solar thermochemical hydrogen production is an attractive technology that stores intermittent solar energy in the form of chemical bonds. Efficient operation requires the identification of a redox‐active metal oxide (MOx) material that can achieve high conversion of water to hydrogen at minimal energy input. Water splitting occurs by consecutive reduction and reoxidation reactions of MOx. MOx is reduced to MOx−δ and, in the second step, is reoxidized by water recovering the initial MOx and generate H2. The material must reduce at temperatures achievable in concentrated solar receiver/reactors, while maintaining a thermodynamic driving force to split water. At equilibrium, extent of reduction depends on temperature and oxygen partial pressure, and in this analysis, a set of thermodynamic properties, namely, enthalpy and entropy of oxygen vacancy formation, is sufficient to represent MOx. Herein, a method to easily classify materials based on these thermodynamic properties under any condition of oxygen partial pressure and temperature is presented. This method is based on fundamental thermodynamic principles and is applicable for any redox material with known thermodynamic properties. Despite the simplicity of the method, it is believed that this analysis will support future research in targeting thermodynamic properties of redox‐active metal oxides.

Computational design of H 2 SO 4 decomposer combined with SOFC for thermochemical hydrogen production

Thermochemical methods, such as the sulfur-iodine cycle and hybrid sulfur cycle, are more advantageous than conventional hydrogen production methods, such as fossil fuel reforming and water electrolysis, for large-scale hydrogen production. Sulfuric acid decomposition is a highly endothermic reaction of the sulfur-iodine cycle. To sustain this endothermic process using high-temperature waste heat from solid oxide fuel cells (SOFCs), we propose an integrated thermochemical reactor combined with SOFC by taking a computational approach. First, a thermodynamic analysis was performed to evaluate the heat production of SOFC to sustain the thermochemical reaction in the combined reactor, resulting in a required waste heat of 0.565 kW from the SOFC that was obtained by consuming 0.0241 kg‧h−1 of H2 to process 1.0 kg‧h−1 of the H2SO4 mixture for the H2SO4 decomposer. For the SOFC inlet temperatures 923, 1023, and 1173 K, the corresponding SO3 conversions of the combined reactor were 72.1%, 77.3%, and 85.1%, respectively. A further increase of over 1200 K in the operating temperature led to a minor improvement in the SO3 conversion efficiency. In the SOFC section, the H2 mass fraction decreased from 67.9% to 10.8% in the anode channel, and 0.169 kW of electrical power was generated when the operating cell voltage and energy efficiency were 0.7 V and 53.71%, respectively.

Analysis and assessment of a new solar assisted sodium hydroxide thermochemical hydrogen production cycle

In this study, a system integration approach is carried out by conducting research on the Sodium Hydroxide (NaOH) thermochemical cycle, one of the thermochemical water separation and hydrogen production methods. The NaOH thermochemical cycle is performed using Aspen Plus commercial software, the chemical 1D software. The present integrated solar energy system is designed using SAM (System Advisory Model) software. With SAM software's help, the physical properties of pure energy storage tanks with molten salt are determined. The system is intended to generate hydrogen and electricity for 24 h. The NaOH thermochemical hydrogen production cycle can produce one kmol of hydrogen per second. The thermochemical cycle's energy and exergy efficiencies are calculated as 80% and 82%, respectively. Overall energy and exergy efficiencies are found as 11% and 13%, respectively.

Exergo‐economic assessment by a specific exergy costing method for an experimental thermochemical hydrogen production system

In this article, an exergo-economic study of an experimental lab-scale integrated copper-chlorine (Cu-Cl) cycle of hydrogen production is conducted. The analysis is performed based on a specific exergy costing (SPECO) method to determine the influences of various design criteria on the costs and then identify possible improvements for more cost effective approaches. The article includes an exergy analysis, economic study, exergy costing and exergo-economic evaluation. Also, a scale-up analysis is performed to predict the cost of a larger scale facility of 1000 kg per day of hydrogen production. The results of the exergo-economic and scale-up analysis are expected to assist in the design, optimization and improvement of a scaled-up Cu-Cl thermochemical cycle. Furthermore, the results of this study show that for a large-scale Cu-Cl cycle plant with a capacity of 1000 kg/day H2, the cost of hydrogen production, excluding the treatment of side reactions, is predicted at about 3.91 $/kg H2.

A distributed energy system integrating SOFC-MGT with mid-and-low temperature solar thermochemical hydrogen fuel production

Solar thermochemical hydrogen production with energy level upgraded from solar thermal to chemical energy shows great potential. By integrating mid-and-low temperature solar thermochemistry and solid oxide fuel cells, in this paper, a new distributed energy system combining power, cooling, and heating is proposed and analyzed from thermodynamic, energy and exergy viewpoints. Different from the high temperature solar thermochemistry (above 1073.15 K), the mid-and-low temperature solar thermochemistry utilizes concentrated solar thermal (473.15–573.15 K) to drive methanol decomposition reaction, reducing irreversible heat collection loss. The produced hydrogen-rich fuel is converted into power through solid oxide fuel cells and micro gas turbines successively, realizing the cascaded utilization of fuel and solar energy. Numerical simulation is conducted to investigate the system thermodynamic performances under design and off-design conditions. Promising results reveal that solar-to-hydrogen and net solar-to-electricity efficiencies reach 66.26% and 40.93%, respectively. With the solar thermochemical conversion and hydrogen-rich fuel cascade utilization, the system exergy and overall energy efficiencies reach 59.76% and 80.74%, respectively. This research may provide a pathway for efficient hydrogen-rich fuel production and power generation.

Thermochemical hydrogen production using Rh/CeO2/γ-Al2O3 catalyst by steam reforming of ethanol and water splitting in a packed bed reactor

This study is focused on investigating the dual performance of Rh/CeO2/γ-Al2O3 catalyst for steam reforming of ethanol (SRE) and thermochemical water splitting (TCWS) using a packed bed reactor. The catalyst is designed to be thermally stable containing an active phase of Rh and the redox component of CeO2 for oxygen exchange, supported on γ-Al2O3. The catalyst has been characterised by SEM, XRD, BET, TPR, TPD, XPS and TGA before testing in the reactor. The optimal temperature for SRE reaction over this catalyst is between 700 °C and 800 °C to produce high concentrations of hydrogen (~60%), and low CO and CH4. The selectivity towards CO and CH4 is higher at low temperatures and drops with rise in reaction temperature. Further, Rh/CeO2/γ-Al2O3 is found to be active for TCWS at relatively low temperatures (≤1200 °C). At temperatures as low as 800 °C, this catalyst is especially found suitable for multiple redox cycles, producing a total of 48.9 mmol/gcat in four redox cycles. The catalyst can be employed for large number of redox cycles when the reactor is operated at lower temperatures. Finally, the reaction pathways have been proposed for both SRE and TCWS on Rh/CeO2/γ-Al2O3 catalyst.

Exergoenvironmental analysis of the integrated copper-chlorine cycle for hydrogen production

Thermochemical water-splitting cycles have the potential of producing large-scale and cost-effective sustainable hydrogen in an environmentally benign manner. Limited exergoenvironmental assessments have been reported in the literature which generally considers thermochemical hydrogen production and specifically the copper-chlorine (Cu–Cl) cycle in thid regard. Thus, the present investigation aims at assessing the four-step integrated Cu–Cl thermochemical cycle set-up located at the Ontario Tech University thereby contributing to the environmental impact assessment of thermochemical hydrogen production. In this study, the exergy analysis of the cycle is first performed by thermodynamically modeling and simulating the cycle in Aspen-plus. The fundamental principles of the exergoenvironmental analysis, analogous to the specific exergy costing (SPECO) methodology of the exergoeconomic evaluation, are applied to the cycle and the balanced environmental impact equations for all cycle components are developed. Based on the balanced environmental impact equations, the environmental impact rate, and the specific environmental impact at each state point is evaluated. The environmental impact levels for all the major cycle components are also obtained. The exergoenvironmental factor, the relative difference of the specific environmental impacts, and the environmental impact rate of exergy destruction for various cycle components are in this regard evaluated. Furthermore, the influence of various parameters on the cumulative and component-related rate of environmental impact as well as the exergoenvironmental factor is analyzed by conducting a detailed sensitivity analysis. According to the obtained results, the rate of environmental impact corresponding to exergy destruction dominates the component-related rate of environmental impact and thus the potential reduction in the cumulative environmental impact for various components could be achieved by improving their exergy efficiencies. The hydrolysis step accounts for 60% of the component-related environmental impact while the thermolysis step accounts for the highest environmental impact of exergy destruction ranging between 41 and 42%. The percentage difference between fossil fuel-based and renewable electricity in terms of the global warming potential ranges between 80% and 98% with the highest difference for wind and nuclear-based electricity.

Enhancement of solar energy use by an integrated system for five useful outputs: System assessment

In this paper, we present a newly developed integrated solar energy based system with a supercritical geothermal, a Brayton cycle gas turbine power plant with heat recovery system, and a thermochemical copper chlorine (Cu-Cl) hydrogen production cycle. The integrated system is capable of producing multiple useful outputs. Solar and geothermal energy sources are utilized with a Brayton cycle with heat recovery system to produce hydrogen, heat, domestic hot water, electricity, and fresh water. Hydrogen is considered to be produced at industrial scale for commercial purposes. Other useful commodities are considered to be utilized for applications in the community which is located in Larderello, Italy. A supercritical geothermal system, a Braytoncycle gas turbine power plant with heat recovery, a parabolic trough concentrated solar power (CSP) plant, a multi-effect desalination (MED) unit, a residential heat pump, and a thermochemical Cu-Cl hydrogen production plant are designed, developed, and investigated. Subsystems and the overall system are simulated for the selected location with various software packages. Energy and exergy approaches are applied to thermodynamically analyze the components, subsystems, and the overall system. The parametric studies are carried out to understand the effects of various parameters on the overall system and its subsystem performances. The overall system is evaluated to operate at 52.6% energy and 47.1% exergy efficiencies for the average ambient conditions for Larderello in Italy.

Outstanding Properties and Performance of CaTi0.5Mn0.5O3–δ for Solar-Driven Thermochemical Hydrogen Production

<h2>Summary</h2> Variable valence oxides of the perovskite crystal structure have emerged as promising candidates for solar hydrogen production via two-step thermochemical cycling. Here, we report the exceptional efficacy of the perovskite CaTi_0.5Mn_0.5O_3–δ (CTM55) for this process. The combination of intermediate enthalpy, ranging between 200 and 280 kJ (mol-O)⁻¹, and large entropy, ranging between 120 and 180 J (mol-O)⁻¹ K⁻¹, of CTM55 create favorable conditions for water splitting. The oxidation state changes are dominated by Mn, with Ti stabilizing the cubic phase and increasing its reduction enthalpy. A hydrogen yield of 10.0 ± 0.2 mL g⁻¹ is achieved in a cycle between 1,350°C (reduction) and 1,150°C (water splitting) and a total cycle time of 1.5 h, exceeding all previous fuel production reports. The gas evolution rate suggests rapid material kinetics, and, at 1,150°C and higher, a process primarily limited by the magnitude of the thermodynamic driving force.

Energy optimization of a Sulfur–Iodine thermochemical nuclear hydrogen production cycle

The use of nuclear reactors is a large studied possible solution for thermochemical water splitting cycles. Nevertheless, there are several problems that have to be solved. One of them is to increase the efficiency of the cycles. Hence, in this paper, a thermal energy optimization of a Sulfur–Iodine nuclear hydrogen production cycle was performed by means a heuristic method with the aim of minimizing the energy targets of the heat exchanger network at different minimum temperature differences. With this method, four different heat exchanger networks are proposed. A reduction of the energy requirements for cooling ranges between 58.9-59.8% and 52.6-53.3% heating, compared to the reference design with no heat exchanger network. With this reduction, the thermal efficiency of the cycle increased in about 10% in average compared to the reference efficiency. This improves the use of thermal energy of the cycle.

Concentrated solar driven thermochemical hydrogen production plant with thermal energy storage and geothermal systems

In this study, a concentrated solar and geothermal based integrated system is thermodynamically investigated to produce useful outputs, such as hydrogen, space heating, electricity, and fresh water. The present system consists of a thermochemical copper-chlorine (Cu–Cl) hydrogen production plant, a geothermal system, a trilateral ammonia Rankine cycle power plant, a multi-effect distillation (MED) desalination unit, a parabolic trough collector (PTC) concentrated solar power (CSP) system with thermal energy storage (TES), and a residential heat pump. As a case study, a hypothetical community is considered near Geysers in California. All produced commodities, except for hydrogen, are utilized for domestic consumption purposes in the community. Hydrogen is supplied to fueling stations in California. One of the most critical requirements of the system, high-grade heat for Cu–Cl cycle, is met by PTC CSP with molten salt TES system. Space heating, electricity, and fresh water productions are powered by geothermal energy systems. Several simulations have been conducted for detailed analyses of the proposed system. Energy and exergy analyses are conducted for the overall system and each component. Some of the subsystems are comparatively assessed and sensitivity analysis is performed to investigate the effects of different parameters on the performance of the entire system as well as various subsystem.Cost assessment studies are conducted for the overall system and its subsystems. 5.5 MWp geothermal and 12.97 MWt solar systems produced 296.9 tons of hydrogen fuel at $2.84/kg cost, 47.6 GWh electricity at $0.03/kWh cost with heat and fresh water due to the simulations. Both energy and exergy efficiencies are found to be 27.4% and 17.3% respectively for the overall proposed system at the ambient conditions.

A new approach in treating industrial hazardous wastes for energy generation and thermochemical hydrogen production

Abstract A new configuration of using hazardous industrial waste incineration system for energy generation and hydrogen production is proposed in this study. A heat recovery steam generator is used to generate steam for the double-stage Rankine cycle for electrical power generation. The additional heat from the incineration unit exhaust gas are employed to generate steam for the thermochemical Cu-Cl cycle. The CO2 emissions carried by the incineration reactor exhaust gases are captured using aqueous ammonia-based carbon capturing system. The Aspen Plus V9 software is employed for the designed system simulation. Numerous sensitivity studies are undertaken to investigate each subsystem of the proposed hazardous industrial waste incineration system. The proposed system generates 7.08 MW of electrical output and hydrogen production flowrate of 12.6 kmol/h. The exergetic and energetic efficiencies of the designed system are found to be 43.3% and 39.1%. Furthermore, the sensitivity analysis results are presented and discussed. The incineration plants treating the waste and converting waste into energy can be substituted for conventional energy production and this proposed environmentally benign integrated system will resolve environmental problems by employing the hazardous industrial waste to the new configuration of the incineration process for producing hydrogen and power with zero CO2 emissions.

A specific exergy costing assessment of the integrated copper-chlorine cycle for hydrogen production

In this study the specific exergy costing (SPECO) approach is employed on a four-step integrated thermochemical copper-chlorine (Cu Cl) cycle for hydrogen production for a second-law based assessment purposes. The Cu–Cl cycle is considered as one of the most environmentally benign and sustainable options of producing hydrogen and is thus investigated in this study due to its potential of ensuring zero greenhouse gas (GHG) emissions. Several conceptual Cu–Cl cycles have been exergoeconomically examined previously, however this study aims at investigating the four-step integrated Cu–Cl cycle developed at the Clean Energy Research Laboratory (CERL) at the Ontario Tech University thereby contributing to the thermo/exergoeconomic assessments of the thermochemical hydrogen production. In this study, the cycle is first thermodynamically modeled and simulated in a process simulation software (Aspen Plus) through exergy and energy approaches. The basic principles of the SPECO methodology are applied to the system and exergetic cost balances are performed for each cycle component. The exergetic costing of each cycle stream is then performed based on the cost balance equations. The purchased equipment cost and the hourly levelized capital cost rates for each cycle component is also obtained. The exergoeconomic factor, relative cost difference and exergy destruction cost rate for various cycle components are also evaluated. Moreover, the effect of several parameters on the total and hourly levelized capital cost rates is analyzed by performing a comprehensive sensitivity analysis. Based on the analysis, the exergy cost, the unit or specific exergy cost, and the unit costs of hydrogen are evaluated to be 6407.55 $/h, 0.042 $/MJ, and 4.94 $/kg respectively.

Exergoeconomic and multi-objective optimization of a solar thermochemical hydrogen production plant with heat recovery

A solar hydrogen production plant based on a four-step copper-chlorine (Cu-Cl) thermochemical cycle is presented and analyzed in this paper. The integrated system includes a pressurized solar power tower, gas turbine unit, phase change material (PCM) for thermal energy storage (TES), Cu-Cl cycle, regenerative steam Rankine cycle (SRC), and a heat recovery unit. A predictive model is developed for energy, exergy, and exergo-economic analyses of the proposed system. A parametric study is also conducted to investigate the effect of major parameters on the system performance. The system is optimized with a non-dominated sorting genetic algorithm-II (NSGA-II) considering exergy efficiency and product cost per unit exergy as the two objective functions. The results indicate that the energy and exergy efficiencies of the overall system are 48.2% and 45%, respectively, while the total product cost per unit of exergy is found to be $10.97/GJ. The integrated solar system produces hydrogen, electricity, and steam at a rate of 0.1 kg/s, 50.49 MW, and 13.93 kg/s, respectively. Pareto solutions for multi-objective optimization indicate that the optimal design point of the system has an exergy efficiency and total product cost per unit of exergy of 50.1% and $11.94/GJ, respectively.