Cycle For Hydrogen Production Research Articles

A comparative analysis of integrating thermochemical oxygen pumping in water-splitting redox cycles for hydrogen production

Solar thermochemical hydrogen (STCH) is a promising route for renewable fuel production, but efficiency and cost concerns must be addressed before it can contribute meaningfully to decarbonization efforts. The oxygen removal (reduction) step of two-step STCH redox cycles needs high temperature (1300–1500 °C) and low oxygen partial pressure (10-5-10-3 bar). This consumes significant energy by way of redox reheating, re-radiation losses and pumping work. Thermochemical oxygen pumping (TcOP) has been shown to be more efficient than mechanical pumps in the medium vacuum range, enabling higher heat-to-fuel efficiency and potentially lower reduction temperatures. We have previously proposed a novel Reactor Train System for STCH and reported significant efficiency and productivity improvements by replacing mechanical pumps with TcOP. The current work is a comparative analysis of different implementations of TcOP and its hybridization with conventional oxygen removal schemes like mechanical vacuum pumps and inert gas sweep. The integration of these hybrid TcOP systems with different STCH reactor systems using redox monoliths or particles is analyzed in terms of energy use along with mass and heat transfer considerations. Our results show that direct oxygen transfer between STCH and TcOP reactors results in the best performance for reduction oxygen partial pressures below 10 Pa. Furthermore, we show that achieving reduction pressures of 1 Pa and lower is challenging with existing reactor systems due to a combination of low gas density and relatively high molar flowrates. This challenge also applies to other oxygen removal systems like vacuum pumps and inert sweep.

Synthesis and testing of NixZn1-xFe2O4/CNTs photoresponsive magnetic composite catalysts for hydrogen generation from water splitting

The world is facing environmental pollution and energy shortage challenges due to the enormous wastage of organic pollutants by industries and the rapid growth of the human population. Photocatalysis has been reported as an efficient technology to mitigate these two emerging issues. This study investigated heterojunction photocatalysts based on NixZn1-xFe2O4/CNTs for enhanced H2 production from water splitting. The role of CNTs in accepting electrons during redox reactions, improving the photocatalytic activity and stability of NiZnFe2O4, and reducing the recombination of charge carriers is also elaborated in this study. The synthesized NixZn1-xFe2O4/CNTs composites were characterized using several methods, including SEM, EDX, FTIR, XRD, and UV–Vis-DRS to examine their magnetic electrical, opto-physical, and photocatalytic activity. The maximum hydrogen evolution rate of 4550 μmolh−1g−1 was observed using N0.4Z0.6FC0.3, which is 5 and 2.3 times greater than that of NZF and Ni0.1Zn0.9FC0.3 catalysts, respectively. The successive cycles of hydrogen production using N0.4Z0.6FC0.3 showed strong stability and reusability of this catalyst. The photocatalytic mechanism of water splitting using NixZn1-xFe2O4/CNTs photocatalysts is also deduced in this study.

Decoupling the anodic and cathodic behavior in asymmetric electrochemical hydroiodic acid decomposition cell for hydrogen production in the iodine-sulfur thermochemical cycle.

The HI section of the iodine-sulfur (I-S) thermochemical cycle for hydrogen production is one of the most energy-intensive sections and with significant material handling challenges, primarily due to the azeotrope formation and the corrosive nature of the hydroiodic acid-iodine-water mixture (HIx). As an alternative, the single-step direct electrochemical decomposition of the hydroiodic acid (HI) to generate hydrogen can circumvent the challenges associated with the conventional multistep HI section in the I-S cycle. In this work, we present new insights into the electrochemical HI decomposition process by deconvoluting the contributions from the anodic and the cathodic sections in the electrochemical cell system, specifically, the redox reactions involved and the overpotential contribution of the individual sections (anolyte and catholyte) in the overall performance. The studies on the redox reactions indicate that the HIx solution output from the Bunsen reaction section should be used as the anolyte. In contrast, aqueous HI without any iodine (I2) should be used as the catholyte. In the anodic section, the oxidation proceeds with I2 as the final oxidized species at low bias potentials. Higher positive potentials result in iodate formation along with oxygen evolution. For the catholyte section, I2 and tri-iodide ion reduction precede the hydrogen evolution reaction when I2 is present along with HI. Furthermore, the potential required for hydrogen production becomes more negative with an increasing I2/HI ratio in the catholyte. Polarization studies were conducted with simultaneous deconvolution of the anodic and cathodic behavior in a two-compartment cell. Model fitting of the polarization data revealed that the anolyte section's activation overpotential is negligibly low. In contrast, the activation overpotential requirement of the catholyte section is higher and dictates the onset of hydrogen production in the cell. Furthermore, the catholyte section dominates the total overpotential losses in the cell system. Operation in the ohmic resistance-dominated zone resulted in close to 90% current efficiency for the electrochemical HI decomposition. The results highlight that the potential for process improvement lies in reducing the ohmic resistance of the anolyte section and in lowering the activation overpotential of hydrogen evolution in the catholyte section.

Enhanced photocatalytic hydrogen production from Co-MOF/CN by nitrogen and sulfur co-doped coal-based carbon quantum dots

A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots (NSCQDs) nanoparticles on the surface of sheet cobalt-based metal-organic framework (Co-MOF) and graphitic carbon nitride (g-C3N4, CN). The structure and properties of the obtained catalysts were systematically analyzed. NSCQDs effectively broaden the absorption of Co-MOF and CN in the visible region. The new composite photocatalyst has high hydrogen production activity and the hydrogen production rate reaches 6254 μmol/(g·h) at pH = 9. At the same time, NSCQDs synergy Co-MOF/CN composites have good stability. After four cycles of hydrogen production, the performance remains relatively stable. The transient photocurrent response and Nyquist plot experimental results further demonstrate the improvement of carrier separation efficiency in composite catalysts. The semiconductor type (n-type semiconductor) of the single-phase catalyst was determined by the Mott–Schottky test, and the band structure was analyzed. The conductive and valence bands of CN are −0.99 and 1.72 eV, respectively, and the conduction and valence bands of Co-MOF are −1.85 and 1.33 eV, respectively. The mechanism of the photocatalytic reaction can be inferred, that is, Z-type heterojunction is formed between CN and Co-MOF, and NSCQDs was used as cocatalyst.

Insights into the stability of the iron oxide immobilized into mesoporous silica catalysts in iodine–sulfur cycle for hydrogen production

Insights into the stability of the iron oxide immobilized into mesoporous silica catalysts in iodine–sulfur cycle for hydrogen production

Enhanced morphological maintenance and redox stability by dispersing nickel ferrite into silica matrix for chemical looping hydrogen production via water splitting

Chemical looping hydrogen production (CLHP) is widely regarded as a clean and efficient route for high purity hydrogen production. However, a huge barrier is how to avoid serious deactivation caused by sintering and agglomeration of oxygen carriers. A novel fabrication process of highly dispersing NiFe2O4 into silica matrix is proposed. The oxygen carriers of NiFe2O4 completely dispersed over silica matrix (NFSM) are successfully synthesized. The characterizations, hydrogen production capacity and cycle redox performance of oxygen carriers are further investigated. The results illustrate that NiFe2O4 active components are homogeneously dispersed on the silica matrix without any impurities. NFSM demonstrates the highest reactivity with CO as well as the greatest hydrogen production of 296 mL/g due to the strong confinement effect of silica matrix and good particle dispersion. The porous silica matrix offers large amounts of channels for the lattice oxygen transport and effectively prevents Fe and Ni cations outward migration to particle surface, which actually inhibits the larger clusters and sintering. NFSM can keep stable hydrogen production of approximately 290 mL/g during the cyclic experiments. Briefly, the innovation method of embedding active component into well-established silica matrix supports contributes to the enhanced anti-sintering properties and redox stability of oxygen carriers.

Process integration of hydrolysis and hydrogen generation processes in the six-step Cu-Cl cycle for green hydrogen production

The ICT-OEC six-step Cu-Cl cycle dissociates water thermochemically to produce hydrogen and oxygen. In the Cu-Cl cycle integrating the hydrolysis and hydrogen processes poses a crucial engineering challenge. Hydrolysis at 350-400 °C requires extra steam, resulting in the generation of dilute HCl instead of dry HCl gas, which must be recycled for hydrogen production. To address this, pressure swing distillation (PSD) is integrated into the hydrolysis and hydrogen generation reactions to separate HCl and water. The study examines operating parameters in PSD processes. A simulated process integration model includes an intermediate heat recovery steam generator (HRSG) with PSD to complete the overall conceptual design. The nuclear-based Cu-Cl cycle without PSD demonstrates a lower environmental impact when compared to the Cu-Cl cycle with PSD. The Cu-Cl cycle with a higher HCl concentration in PSD feed exhibits a minimum global warming potential (GWP) value of 2.53 kg of CO2 eq for 1 kmol/h hydrogen production.

Analysis of the Efficiency of Hydrogen Production Technology at Mini-CHP Plants Using Local Fuelsby Thermochemical Method

Within the framework of the policy of “decarbonization” of the economy, a technology for hydrogen producing from local fuels (LF) and combustible waste of human activity is proposed as a part of the development of the functionality of heating cycles of energy production. The aim of the present study is to evaluate the energy efficiency of a steam-powered mini-CHP plant operating on local fuels with a thermochemical hydrogen production module. A brief literature review of thermochemical cycles of hydrogen production is presented, and it is shown that hybrid copper-chlorine Cu–Cl cycles are recognized as the most promising. In the Aspen Hysys software environment, a mathematical model of a mini-CHP plant with a five-stage hydrogen production cycle was synthesized, which can later be used as a component in the digital twin. According to the results of the analysis of the mathematical model, it was determined that the specific consumption of electric energy per 1 kg of hydrogen for such a scheme will be 9.11 (kW×h)/kg, which is on average more than five times less than in the production of hydrogen by electrolysis, the rest of the required energy is replaced by thermal one, while the maximum fuel utilization factor of mini-CHP with a hydrogen production module using wood waste as fuel amounted to 83.1 %, including a thermal efficiency of 51.5 %, the efficiency of hydrogen production at the lowest calorific value is 31 %, the electrical efficiency for the supply of electricity to the grid is 0.6 %. For comparison, the maximum fuel utilization of a steam-powered mini-CHP of the same electrical capacity reaches 90.9 %. The expansion of mini-CHP options operating on local fuels by introducing a hydrogen production unit by hybrid thermochemical method into its scheme makes it possible to increase the maneuverability of the station, which implies the possibility of organizing the operation of mini-CHP in accordance with the requirements of thermal consumers and electrical graph-reducing the loads of the power system during the hours of maxima and minima of its consumption by changing the electrical power supply to the network or increasing the power consumption of electricity from the external network to the power required for hydrogen production. In conclusion, the possibility of developing the studied scheme of a mini-CHP operating on local fuels towards further utilization of combustion products in order to generate artificial natural gas, which in this case can be called “green”, is indicated.

Dynamic Modelling and Process Control of Iodine-Sulfur Thermochemical Cycle for Hydrogen Production: A Bibliometric Study and Research Prospect

Dynamic Modelling and Process Control of Iodine-Sulfur Thermochemical Cycle for Hydrogen Production: A Bibliometric Study and Research Prospect

Energy saving in Cu-Cl thermochemical cycle for green hydrogen production: Use of heat integration approach and simulation tools

Hydrogen, both green and blue, is a crucial fuel as it carries energy from sustainable sources and has no impact on global warming. Thermochemical methods for green hydrogen generation are promising alternative technologies to previous technologies for the commercial-scale generation of hydrogen gas without fossil fuel. In the present work, ICT-OEC six-step copper-chlorine (Cu-Cl) thermochemical cycle is explored, its efficiency is investigated using the Aspen Plus simulation software, and probable efficiency enhancements are addressed. Using the Aspen energy analyzer, different design configurations for the heat exchanger network were proposed, and thermal management within the cycle was studied. The implementation of thermal management strategies yielded a substantial enhancement in the efficiency of the Cu-Cl cycle, elevating it from 38.68% to 51.54%. The comparative analysis of the 6-step Cu-Cl cycle with other 3-, 4-, and 5-step cycles revealed that the 4-step Cu-Cl cycle (UOIT-CERL, Canada) exhibited higher energy efficiency. However, the 6-step Cu-Cl cycle shows greater promise for commercialization.

Modeling and multi-objective optimization of a solar-boosted gas turbine cycle for green hydrogen production and potable water production

Global warming has caused lots of problems in recent years. Renewable energy can be a solution to this problem. In this research, a multigeneration system is modeled including a concentrated solar plan, Brayton cycle, Rankine cycle, organic Rankine cycle, absorption chiller, single-stage flash desalination, humidification, and dehumidification desalination, and PEM electrolyzer to produce power, cooling load, desalinated water, and hydrogen. The system is modeled in EES software. The results show that the system's overall energy and exergy efficiency is 46.6 % and 43.11 %, respectively. The total power production is 7533 kW after modeling the system in EES, by using a neural network, the data was transferred to MATLAB software. In MATLAB, multi-objective optimization was performed using the genetic algorithm to maximize exergy efficiency and minimize the cost rate. The optimized results show that the overall energy and exergy efficiencies are 46.1 % and 42.1 %, respectively. The total power production is 7628 kW.

Cost assessment of selected nuclear driven hybrid thermochemical cycles for hydrogen production

This article presents compared cost assessment of selected nuclear-driven hybrid thermochemical cycles using International Atomic Energy's (IAEA) Hydrogen Economy Evaluation Program (HEEP). Cost estimations are made and evaluated for capital, fuel, decommissioning, O&B, and consumables, in addition to thermal energy and electricity cost details. Thanks to the data obtained with these cost estimates, 4 different nuclear hydrogen production systems were evaluated comparatively. Hybrid thermochemical cycles are expected to decrease operational expenses for hydrogen production. However, the capital expenses might be higher than pure electrolysis since they require more components for balance of plant components (BoP). The results obtained indicated that the levelized cost of hydrogen is 10%–30% less in the case of selected hybrid thermochemical cycles than that of pure electrochemical cycle.

Optical and thermal analysis of solar parabolic dish cavity receiver system for hydrogen production using deep learning

The solar thermochemical cycle, responsible for converting solar energy to chemical fuel, is an emerging clean hydrogen production technique. The distribution of the concentrated heat flux and temperature on the receiver is crucial in deciding solar-to-fuel conversion efficiency. Thus, the optimum configuration of a solar parabolic dish collector (PDC) is necessary for providing efficient thermal energy. The dish diameter, rim angle, and distance of the receiver aperture from the focal point of the dish characterize the optimization of the PDC. The non-uniform heat flux captured is coupled with a heat transfer model of a solar thermochemical reactor for a thermal dissociation of ZnO involved in a ZnO/Zn thermochemical cycle for hydrogen production. The directly irradiated rotating reactor comprises a cylindrical cavity packed with insulation layers and a quartz glass window. The rotating cavity is loaded with ZnO granular particles held by a centrifugal force. A 3D CFD numerical model is analyzed by coupling the Eulerian multiphase model for ZnO particle dynamics, fluid flow of gaseous mixture, RNG k-ԑ turbulence model, Energy and Discrete Ordinates (DO) radiation model, and Arrhenius reaction rate chemical reaction of ZnO dissociation. A numerical model with non-uniform heat flux input is validated for a cavity temperature, mass fraction of zinc and oxygen, and oxygen molar flow rate at the reactor outlet. An artificial neural network model is adopted to predict the heat flux and uniformity factor values of PDC. Correlation Coefficient (R2), Root Mean Square Error (RMSE), and Mean Absolute Percentage Error (MAPE) error metrices were used to evaluate the model's performance having the receiver diameter (d), the dish diameter (D), the rim angle (φ), and the distance between the focus and receiver (h) as input variables.

Hydrolysis phase equilibrium in various reactor configurations of the thermochemical Cu–Cl cycle

This study examines the phase equilibrium trends of the hydrolysis process in the thermochemical Cu–Cl cycle of hydrogen production. Various temperatures, pressures, and steam to copper ratios are modelled to predict CuCl2 conversion and progression of side reactions within the hydrolysis reactor. Novel reactor configurations, such as Moving Bed Reactors (MBRs), reactors in series and outlet gas recirculation are introduced within the analysis. Optimal conversion of CuCl2 and minimal by-product generation are obtained at a reactor temperature of 375 °C and pressure of 1 bar with improved conversion at higher temperatures and lower pressures. Improved reaction conversion is identified at higher steam to copper ratios. A 10:1 steam to copper ratio was used for the remaining reactor configuration scenarios. Reactors in series were simulated to mimic MBR behaviour. Three reactors in series with 10 kmol total steam consumption showed better conversion of 1 kmol of CuCl2 by 17% compared to a single reactor with the same steam inlet conditions. Mitigation of CuCl2 and Cu2OCl2 decomposition was also observed. The outlet gas recirculation improved the total desired product yield, however, the maximum conversion of CuCl2 was significantly impacted due to the high level of HCl concentrated steam. A combination of the gas outlet stream and reactors in series provide a method to improve the conversion rate. This reactor configuration is a challenging approach unless there is a separation technique to shift the reaction equilibrium or reduce HCl concentration within the gas stream.

Waste heat recovery potential in the thermochemical copper–chlorine cycle for hydrogen production: Development of an efficient and cost-effective heat exchanger network

With the finite nature of fossil fuel resources and related environmental issues, it is necessary to replace fossil-fuel-based hydrogen production methods with more sustainable ones. For the clean production of hydrogen, the copper-chlorine (Cu–Cl) thermochemical cycle is a favorable choice. However, internal waste heat recovery of the cycle is essential to improve the efficacy of the system. In this paper, the waste heat recovery potential of the four-step Cu–Cl cycle is investigated, to support the design of a new cost-effective and high-performance heat exchanger network. Pinch analysis is executed to find the optimum rates of cold and hot utilities for this cycle. Three heat exchanger network cases are investigated which include case 1, without heat recovery; case 2, with 16 heat exchangers; and case 3, with 11 heat exchangers. The effect of varying design parameters on the energy system's efficiency and cost-related parameters are also explored here. Based on the pinch analysis results, the minimum heating and cooling and the maximum recoverable heat, on a normalized basis, are 333.3 kJ/mol H2, 76.9 kJ/mol H2, and 134.4 kJ/mol H2, respectively. Moreover, for cases 1, 2, and 3 the thermal efficiencies are calculated as 33.3%, 41.1%, and 40.5%, respectively. Additionally, it is observed that, when the thermal energy of the cycle is supplied from a solar power tower plant, the levelized cost of hydrogen for case 1 is 9.6 $/kg H2, for case 2 is 7.9 $/kg H2, and for case 3 is 7.8 $/kg H2.

Using machine learning for comparative optimizing a novel integration of molten carbonate and solid oxide fuel cells with CO2 recovering and gasification

The effects of global warming on the environment and society are substantial, making it a major global concern. Finding strategies to reduce CO2 output from energy systems that rely on chemical processes is one of the biggest problems in this area. In order to address this challenge, researchers are looking into creative solutions, such as carbon capture and storage and developing alternative energy systems with low carbon footprints. For this, the present work introduces a creative integration of molten carbonate and solid oxide fuel cells to maximize efficiency while reducing energy costs. This system also has a recovery unit to reuse the generated CO2 as the gasification agent for reduced environmental impact. Besides, the surplus heat is exploited through the vanadium chloride cycle for clean hydrogen production. A techno-economic, sustainability, and exergo-environmental assessment is carried out to evaluate the system's feasibility from all facets. According to the parametric results, there is a conflictive trend among performance indicators by changing the fuel utilization factor and compressor pressure ratio. Therefore, a comparative analysis of various multi-objective optimization scenarios is performed to find the best condition from various perspectives. According to the findings, compared to the system without a recovery unit, the proposed model produces optimal hydrogen of 1.3 kg/s with a very low environmental effect and power costs of 5.3 kg/GWh and 19.4 $/MWh. The results further reveal that when power is considered an additional optimization goal, it increases up to 494.95 MWh, resulting in the lowest environmental effect and the cost of 4.4 kg/GWh and 16.3 $/MWh, respectively. The scatter distribution of the key variables ultimately reveals that, while the current density should be maintained at its highest level, the optimal points of utilization factor are distributed throughout the entire domain.

Multi-objective optimization of hydrogen production system based on the combined supercritical cycle and gas turbine plant

In this paper, considering the hydrogen production cycle coupled with the supercritical CO2 cycle, hydrogen is produced as a clean fuel along with power and heat production. Also, the world's need for clean energy doubles the solutions to achieve clean hydrogen energy. The investigated cycle has a supercritical CO2 cycle with a combustion chamber where enriched fuel is introduced. Combustion products produce work in the gas turbine, and further hydrogen separation is formed with the help of water gas shift reaction and hydrogen separation membrane. In the thermodynamic analysis, combustion chamber known as the most irreversible member of set, where the most exergy is lost. The energy and exergy efficiency for whole set are 64.82%, 52.46% respectively. Produced hydrogen mass flow rate calculated 46.8 kg/h. Also, multi-objective optimization based on genetic algorithm were done and the results were reported. All calculation and optimization method has been done in MATLAB software.

Process design of a thermochemical cycle for hydrogen production compatible with nuclear fusion heat sources

We quantitatively design a hydrogen-producing copper–chlorine thermochemical cycle that is thermally combinable with nuclear fusion reactors. The mass and heat balances throughout the cycle, including the hydrolysis, pyrolysis, and electrolysis reaction processes, accompanied by multiple separation steps, are numerically investigated. Through the process design, the feasibility of the practical operation of the hydrogen production cycle is presented, and the thermal and electric power required for the operation is evaluated. As we first design a process with straightforward employment of the exact reaction condition from an earlier experimental study of the electrolysis process, the heat required for the condensation of CuCl2 solution is found enormous. By modifying the process condition with an increased electrolyte concentration, to reduce the amount of H2O to be evaporated in the CuCl2 condensation, the total heat for the cycle significantly decreases from 1270 GJ·h−1 (20.3 MJ·mol-H2−1) to 204 GJ·h−1 (3.26 MJ·mol-H2−1). This value is still larger than the heat required for hydrogen production by H2O electrolysis, 48.2 GJ·h−1 (0.772 MJ·mol-H2−1), but an extrapolation towards the saturated CuCl concentration achieves 46.0 GJ·h−1 (0.736 MJ·mol-H2−1). For energy-cost performance improvement of the thermochemical cycle, the development of the electrolytic cell operable with a high concentration of CuCl aqueous solution is thus found to be of primary effectiveness.

Coupling the full solar spectrum with a two-step thermo-electrolytic cycle for efficient solar hydrogen production

H2O splitting via redox cycles of metal oxides provides a promising path for solar hydrogen production. For various redox cycles with hybrid driving forces, the introduction of spectral splitting is expected to reduce the exergy degradation at the initial step and realize the cascade utilization of the full solar spectrum. A thermodynamic model coupling the full solar spectrum with a two-step thermo-electrolytic cycle was established in this work, based on which the cycling performance was theoretically examined. Solar spectral splitting at an adjustable cut-off wavelength was employed to allow for a flexible allocation of the solar spectrum to meet the thermal and electrical energy demands of the cycle. Solar-to-H2 efficiency can be significantly improved by the introduction of spectral splitting. It can be as high as 35.4% for the redox cycle performed with CeO2-δ, and the optimal reduction temperature can be lowered from 1323 K to 1123 K. Isothermal cycles have an efficiency advantage over non-isothermal cycles due to the elimination of the energy cost for oxygen carrier heating. However, they are also accompanied with lower H2O conversion rates and higher oxygen carrier demands, for which a compromise may be needed from a practical view. Oxygen carriers with lower oxygen affinity were shown to have a higher efficiency potential than pure ceria (CeO2-δ). However, as the reduction enthalpy drops close to or even lower than the enthalpy of direct H2O splitting, the efficiency decreases fast due to insufficient driving force for the oxidation reaction.

4E analysis and machine learning optimization of a geothermal-based system integrated with ejector refrigeration cycle for efficient hydrogen production and liquefaction

This study presents a new geothermal-based system for power generation and liquid hydrogen production. Depending on the network requirements, part of the generated power is supplied to the network and the remaining part enters the PEM electrolyzer to produce hydrogen. The produced hydrogen is then pre-cooled by the ejector cooling cycle before entering the liquefaction cycle. The ejector refrigeration cycle not only uses geothermal waste heat but also facilitates the liquefaction process through precooling hydrogen; therefore, it significantly improves the overall performance of the integrated system. In addition, the modified liquefaction cycle is suggested, which is superior to common ones. After simulating, some key parameters are identified and a comprehensive parametric research is carried out to investigate the thermodynamic, economic and environmental performance in different conditions. The optimization procedure is implemented through a genetic algorithm approach and the objective functions are defined. The results reveal that the double flash power cycle has the greatest effect on exergy destruction rate and total cost rate. In the optimal case, the total cost rate, the liquefied hydrogen rate, the total exergy efficiency, net power generation, and CO2 reduction rate are determined as 181.71 $/h, 59.92 kg/h, 25.27%, 4.03 MW, and 1421.2 kg/h, respectively. Also, coupling an artificial neural network with genetic algorithm significantly lessens optimization time.