Hydrogen Liquefaction Process Research Articles

Optimization and analysis of a novel hydrogen liquefaction coupled system with dual path hydrogen refrigeration cycle and the closed nitrogen cycle pre-cooling

The high cost and inefficiency of the hydrogen liquefaction process have impeded the growth of the liquid hydrogen industry. Through the analysis of existing hydrogen liquefaction systems, a novel compact hydrogen liquefaction system that can reduce energy consumption is developed. The system comprises a closed cycle of nitrogen pre-cooling process and dual hydrogen refrigeration cycle cryo-cooling process that are integrated to form and create the coupled system. To evaluate the performance of the proposed hydrogen liquefaction system, an independent system is additionally constructed for comparative analysis, which separates the pre-cooling process and cryo-cooling process. The parameters are optimized using a genetic algorithm for both independent and coupled systems. The results show that the specific energy consumption, coefficient of performance and exergy efficiency of the coupled system are 11.41 kWh/kgLH2, 0.12 and 26.1%, respectively. Furthermore, the coupled system demonstrates significant performance, where the useful and recoverable exergy of the coupled system surpasses that of the independent system. The coupled system's exergy destruction and total UA values decrease by 7.25% and 40.93%, respectively. Moreover, the economic evaluation shows that the total annual cost of the coupled system is $6.22 million per year. The total system cost is sensitive to the electricity price, and the operating expenditure as a percentage of total annualized cost increases from 16% to 53% when the operating electricity price increases from $0.01 to $0.06. This study aims to support the practical development of future hydrogen liquefaction systems by optimizing the cooling system structure.

4E analysis for a novel cryogenic hydrogen liquefaction process using various refrigerants: Energy, exergy, economic, and environment

Hydrogen liquefaction process (HLP) is a principal technology to overcome energy storage and transportation problems and to meet the demand for an eco-friendly energy source. This study proposes three conceptual designs of HLPs with various refrigerant cycles. The specific energy consumption (SEC) of HLP could be reduced by various refrigerants. Three different refrigerants (liquid air (LA)), liquified natural gas (LNG), and mixed refrigerants (MR)) were compared to the conventional LN2-based HLP to verify 4E (efficiency, exergy, economics, and environmental) of each process based on their thermodynamic properties. From the results, we found that the process performance, economics, and environmental effects of the LNG-based hydrogen liquefaction process (LNG-HLP) were the best. In particular, the LNG-HLP, which uses the cold energy of LNG, required less refrigerant than LN2, thereby reducing the energy consumed by major compressors. It had an SEC of 11.04 KWh/kg-LH2 and capital, operating cost, and CO2 emissions of the LNG-HLP process were considerably lower by 5.5 %, 6.2 %, and 12.2 % (unit kg CO2eq/kg LH2), respectively, compared to the conventional process. To propose better economic or environmental scenarios to stakeholders and governments, in this study, the HLP and hydrogen production processes were expanded to include CO2 emission calculation and carried out analysis for levelized cost of hydrogen contribution rate to electricity production types by country.

Comparative energy and exergy analysis of ortho-para hydrogen and non-ortho-para hydrogen conversion in hydrogen liquefaction

This study reports the comparative energy and exergy analysis of ortho-para hydrogen and non-ortho-para hydrogen conversion in hydrogen liquefaction process. Two cases were simulated, case A – hydrogen liquefaction with ortho-parahydrogen conversion and case B – hydrogen liquefaction without ortho-parahydrogen conversion. This is the first study that presents a comparative energy and exergy analysis between such two cases. In this research, a hydrogen liquefaction process was designed adopting cascaded five-stage Brayton refrigeration cycle. The process was simulated in Aspen PLUS. The process used a mixed refrigerant (of liquefied natural gas) refrigeration cycle to precool the gaseous hydrogen feed from 26 °C temperature to −192 °C temperature, and mixed refrigerant (of nelium) was subsequently used to further deep-cool the the hydrogen stream from −192 °C temperature to −245.99 °C temperature in the cryogenic section of the process. Liquefaction was achieved by expanding the hydrogen through Joule-Thomson valve at −248.37 °C and 1 bar. The simulated results of the two cases showed the specific energy consumption of case A to be 8.45 kWhr/kgLH, and that of case B to be 15.65 kWhr/kgLH respectively. The results also indicated a total exergy efficiency of 92.42% in case A and 87.18% in case B. The research results showed that the hydrogen liquefaction designed with configuration of ortho-parahydrogen conversion has better performance indicators than the liquefaction without ortho-parahydrogen conversion. Therefore, hydrogen liquefaction with ortho-parahydrogen conversion can be considered in the design and development of new hydrogen liquefaction plants. Process optimization is recommended to further enhance the specific energy consumption and exergy efficiency of both processes.

Thermodynamic analysis and optimization of hydrogen liquefaction system with binary refrigerant precooling cycle

A hydrogen liquefaction process is proposed with the liquid natural gas utilization, binary refrigerant precooling and helium cryogenic cycles combined, and a general model is built for analyzing the variation of hot and cold composite curves and heat transfer temperature difference (HTTD) along with refrigerant parameters. The relationship between temperature and enthalpy of the precooling cycle and the variation of HTTD are deduced. Based on this, the composite curves and HTTD curves are constructed, and the influence of refrigerant on the HTTD and the refrigerant outlet temperature is analyzed. The optimization procedure of refrigerant is proposed based on the temperature-enthalpy relationship and HTTD considering the temperature glide. For the proposed hydrogen liquefaction system, the optimal binary refrigerant includes 60.21 % nitrogen and 39.79 % propane (mass fraction), and its mass flow rate and inlet temperature are 23,821.96 kg/h and −199.72 °C, respectively. The corresponding specific energy consumption (SEC) of the hydrogen liquefaction system is 4.44 kWh/kgLH2, reduced by 10.30 %, and the coefficient of performance (COP) and exergy efficiency are 27.10 % and 28.26 %, increased by 11.34 % and 17.80 %, respectively.

Energy optimization of hydrogen liquefaction process via process knowledge combined with multivariate Coggin's algorithm

Sustainable and cost-effective transportation of hydrogen is one of the major challenges to futuristic hydrogen value chain. Hydrogen, in its produced form, exhibits low energy density and large volume, rendering it highly unsuitable for transportation, particularly over extended distances. Liquefaction is one of the promising approaches to improve hydrogen's energy density and to make it more compact. However, liquefaction is an energy intensive process, raising the cost of transportation. In this study, the specific energy consumption of the hydrogen liquefaction process is aimed to reduce through knowledge-based optimization followed by optimization using the multivariate Coggin's algorithm to improve energy and economic profiles of the process. Design variables, composite curve, exergy, and economic analyses are performed to evaluate and compare the thermodynamic, economic, and environmental feasibility of the optimized process. The results depict a significant reduction (14.3%) in specific energy consumption to 9.40 kW/kgLH2 without increasing process complexity. Further key improvements include a massive drop in refrigerant flowrates (9.2%), annualized cost (m$ 0.15), and annual CO2 emissions (1008.45 tCO2/annum). The largest exergy destruction is observed in CHX-201, reflecting further room for improvement. These results underscore the potential for optimizing hydrogen liquefaction processes to enhance energy efficiency, process economics and environmental impact, providing valuable insights for researchers and industry professionals seeking to advance hydrogen liquefaction technologies. However, challenges remain in the comprehensive evaluation of chemical exergy for ortho- and para-hydrogen and in conducting advanced exergy analyses to further optimize hydrogen liquefaction processes without adding complexity.

Research on matching supply of power and cold energy of liquid hydrogen cold chain logistics vehicles

Liquid hydrogen cold-chain logistics vehicle (LHCCLV) is a special vehicle using liquid hydrogen (LH2) as the source of both power and cold energy. A significant weakness of LH2 is its high energy consumption during the hydrogen liquefaction process, thus the utilization of cold energy in LHCCLV can improve the economic performance and competitiveness of LH2. Because of the high energy storage density of LH2 and the relatively high efficiency of fuel cells, we find that cold energy can not meet the demand of LHCCLV. Therefore, we consider enlarging the cold energy by efforts including the para-ortho hydrogen conversion (POC), whose reverse reaction consumes an energy level exceeding 20% during the hydrogen liquefaction process. In this paper, numerical models of discharging hydrogen from the LH2 and subcooling hydrogen tank are established, and the influence of POC and other efforts on the supply of cold energy is analyzed. The changes in instantaneous and total cold energy supply under different working conditions are analyzed, and the important influence of POC and other efforts is confirmed. The beneficial effect of POC is quantified in the paper, especially for the cold energy supply. This paper provides an essential reference for the research and development of LHCCLV. Also, it guides the comprehensive utilization of cold energy in other situations to promote the improvement of the economy of hydrogen energy utilization routes in the form of LH2.

Artificial intelligence-based surrogate modeling for computational cost-effective optimization of hydrogen liquefaction process

The chemical processes are inherently complex, and obtaining desired product quality and high energy efficiency by optimizing the design variables is challenging. The progress in computing technologies can be a blessing since machine learning models can process the information and data for learning purposes and eventually help ease the simulation and optimization efforts. Against this backdrop, an artificial neural network-based surrogate model is developed in the present study and applied to the challenging process of hydrogen liquefaction. Optimization of hydrogen liquefaction processes is still an open challenge because of convergence issues and many design variables; only a handful of algorithms are considered successful. One of those algorithms, particle swarm optimization (PSO), is used here to compare computational effort and results accuracy. The percentage error of prediction of the ANN-based surrogate model compared to PSO was 4% for the minimum internal approach temperature, which is usually considered as a constraint, and 0.04% for specific energy consumption considered as the objective function. The optimization of the proposed model significantly reduced the time needed for PSO optimization of the existing model by more than 99.99%. As an extension of the current work, the ‘shallow' neural network model, with one hidden layer used in the present study, can be used to analyze the whole liquefaction process.

Study on a novel hydrogen liquification process applying mixed-refrigerant for pre-cooling and cryogenics

Reducing the energy consumption of hydrogen liquefaction process is an urgent issue to improve the economy of liquid hydrogen transportation. A novel large-scale hydrogen liquefaction system, with a capacity of 100 TPD, is proposed in this paper. The pre-cooling system is composed of a mixed-refrigerant (MR) refrigeration cycle and a CO2–NH3 cascade refrigeration cycle. Due to the auxiliary pre-cooling effect of the CO2–NH3 cascade cycle, temperature of the pre-cooled hydrogen can be as low as −200.9 °C. A modified MR Joule Brayton cycle with an additional compressor is used as the cryogenic system to cool the hydrogen from −200.9 °C to −252.2 °C. Besides, a four-stage ortho-to-para conversion (OPC) process is utilized. Performance of the novel system is investigated and optimized using the Aspen HYSYS software. According to the results, the lowest specific energy consumption (SEC) of the proposed process is 6.15 kWh/kgLH2 and the exergy efficiency is as high as 67.4%. Based on the energy analysis, the best system coefficient of performance is 0.1751 with a 96.3% of p-H2 in the liquid hydrogen. In addition, compared to the initial conceptual system, the proposed system exhibits significant performance enhancements, a 20% reduction in SEC and a 27.9% increase in exergy efficiency. A sensitivity analysis is conducted to assess the impact of refrigerant composition and hydrogen pressure on the system, resulting in the determination of the optimal proportions of refrigerant components and the optimal inlet pressure. Results of the study can provide theoretical reference for the further development of large-scale hydrogen liquefaction technology.

A novel hydrogen liquefaction process using dual mixed cryogenic refrigeration system: Energy, exergy, and economic analysis

In conventional hydrogen liquefaction plants, the liquefaction process consumes high portion of about 30 % of the liquid hydrogen (LH2) energy content. In addition, existing LH2 technology uses pure or single mixed refrigerants, which are susceptible to freezing problems. To address these challenges, this study introduces an innovative hydrogen liquefaction process utilizing dual mixed refrigeration (DMR) system. This process incorporates two interactive mixed refrigerants in two integrated refrigeration loops, offering flexible capability to handle large-scale capacities with minimal energy consumption and free of freezing problems. The proposed process achieved extremely low specific energy consumption (SEC) of 3.732 kWh/kgLH2, 48 % lower than the average SEC of the large-scale single mixed refrigerant (SMR) systems (7.128 kWh/kgLH2). Also, its exergy efficiency (59.65 %) is 33 % higher than the average exergy efficiency of the SMR-based systems (44.89 %). Furthermore, the proposed DMR-based process reduces the levelized cost of liquid hydrogen production to 1.89 $/kgLH2, which is 70 % lower than the small-scale processes and 21 % lower than the average cost of the large-scale SMR-based systems. This study of the dual mixed cryogenic refrigeration approach provides new methodology and guidelines for future research to significantly improve the technical and economic feasibility of LH2 production, making it competitive with other energy storage and transportation options.

Hydrogen Liquefaction Process with Mixed Refrigerant Pre-cooling

Hydrogen Liquefaction Process with Mixed Refrigerant Pre-cooling

The thermodynamic analysis on the catalytical ortho-para hydrogen conversion during the hydrogen liquefaction process

The catalytic conversion of ortho-para hydrogen is an important part in the hydrogen liquefaction process. Isothermal conversion, adiabatic conversion and continuous conversion are three main methods of the catalytic conversion in the hydrogen liquefaction process. However, there are few studies on the analysis and comparison of the three methods. In this paper, a theoretical model of the hydrogen liquefaction process is developed and calculated by MATLAB. The influences of the conversion methods, the number of adiabatic conversion stages and the parahydrogen concentration requirements in products are discussed and analyzed. The results show that the consumption work of the hydrogen liquefaction process with continuous conversion is the lowest. The consumption work of the isothermal conversion is 29.42 % higher than that of the continuous conversion, the consumption work of the adiabatic conversion with different stage numbers is 3.00 %–15.67 % higher than that of the continuous conversion when the parahydrogen percentage requirement in the product is 95 %.

Numerical and experimental study on the falling film flow characteristics with the effect of co-current gas flow in hydrogen liquefaction process

Liquid hydrogen storage and transportation is an effective method for large-scale transportation and utilization of hydrogen energy. Revealing the flow mechanism of cryogenic working fluid is the key to optimize heat exchanger structure and hydrogen liquefaction process (LH2). The methods of cryogenic visualization experiment, theoretical analysis and numerical simulation are conducted to study the falling film flow characteristics with the effect of co-current gas flow in LH2 spiral wound heat exchanger. The results show that the flow rate of mixed refrigerant has a great influence on liquid film spreading process, falling film flow pattern and heat transfer performance. The liquid film of LH2 mixed refrigerant with column flow pattern can not uniformly and completely cover the tube wall surface. As liquid flow rate increases, the falling film flow pattern evolves into sheet-column flow and sheet flow, and liquid film completely covers the surface of tube wall. With the increase of shear effect of gas-phase mixed refrigerant in the same direction, the liquid film gradually becomes unstable, and the flow pattern eventually evolves into a mist flow.

Exergy and energy analysis of a hybrid natural Gas/Hydrogen liquefaction cycle combined with methanol production plant

This paper presents an innovative renewable multi-generation system designed to simultaneously produce various fuels, including biomass-based methanol, liquid hydrogen, and liquid natural gas. This system is part of a broader strategy aimed at streamlining different processes within a comprehensive plant, enabling the simultaneous production of multiple biomass-based fuels at a single location. The implementation of this system in regions where natural gas liquefaction plants coexist with abundant forest resources allows for the efficient production of all required fuels. In this process, a new configuration leverages to regenerate the waste heat of methanol synthesis process in the diffusion absorption refrigeration cycle integrated to the natural gas liquefaction process to maximize energy and exergy efficiencies. Additionally, three hydrogen liquefaction processes are evaluated to identify the most suitable option based on performance, efficiency, and power consumption. The investigations reveal that the combined mixed refrigerant cycle (CMRC) emerges as the ideal choice for hydrogen liquefaction process, characterized by lower power consumption and a higher coefficient of performance. The energy and exergy efficiencies of biomass gasification and methanol synthesis processes are 87.54% and 80.41%. The energetic coefficient of performance of the natural gas liquefaction process and CMRC is 0.9 and 0.2209. The specific power consumption of natural gas liquefaction process is 0.225 kWh/kgLNG, and the specific power consumption of CMRC is 5.462 kWh/kgLH2. The natural gas liquefaction process is responsible for the highest portion of the total exergy destruction, with 32%.

Effect of unpaired electron number elements (Al, Cr, Mn) doping in Fe2O3 on ortho to para hydrogen conversion at 77 K

Para hydrogen (p-H2), as a low-energy spin isomer of hydrogen molecule, has an important significance in the storage and transportation of liquid hydrogen. The ortho hydrogen (o-H2) to p-H2 conversion catalyst accelerates the intrinsically slow o-H2 to p-H2 conversion and becomes an essential component of the hydrogen liquefaction process. In this paper, doped Fe2O3 with different hetero elements (X-FO, X = Al, Cr, Mn) are prepared by a simple co-precipitation method to explore the effect of different unpaired electron numbers in doping elements on catalytic performance. It is shown that the disorder in the internal crystal structure of X-FO caused by doping of hetero elements is the main reason for the increased performance of X-FO, as this leads directly to an increase in the internal magnetic disorder. The catalytic performance is enhanced with the increase in the number of unpaired electrons in doping elements. Mn-FO with high unpaired electron number exhibits optimal catalytic performance. When the hydrogen flow rate is 100 mL min−1, p-H2 content is 49.45 % after catalytic conversion at 77 K. In this paper, a simple method is adopted, which has advantages in terms of production process and cost, and provides experimental support for the large-scale production of catalysts.

Thermodynamic and economic analysis of new coupling processes with large-scale hydrogen liquefaction process and liquid air energy storage

Liquid hydrogen serves as an environmentally friendly energy carrier, playing a crucial role in alleviating greenhouse effects. In order to tackle the challenges concerning energy consumption and economic costs, it becomes imperative to develop an efficient and cost-effective large-scale hydrogen liquefaction process (LHLS). This study integrates of LHLS with liquefied air energy storage (LAES) and introduces three liquefaction processes to reduce the economic cost associated with hydrogen liquefaction. By coupling LAES, electricity generated during off-peak hours can be stored and subsequently utilized in LHLS operations during peak hours, leading to a reduction in electricity costs. Furthermore, utilizing the surplus cooling capacity of LAES can enhance the efficiency of LHLS. A genetic algorithm is used to optimize the coupling processes. The calculated total annual cost (TAC) of the most economically viable coupling process amounts to 12271.8 k$/year, representing in a 20.91 % reduction compared to the independent LHLS. This indicate a clear economic advantage with the coupling process. The levelized cost of hydrogen (LCOH) and the payback period (PBP) for this particular coupling process are 2.523 $/kg and 4.56 years, respectively. A sensitivity analysis reveals that the economic benefits of the coupling processes escalate with higher electricity prices and greater liquefaction capacity.

An energy-saving hydrogen liquefaction process with efficient utilization of liquefied natural gas cold energy

Storage and transportation of hydrogen in liquid form offers considerable advantages, but the high energy consumption of hydrogen liquefaction processes needs to be addressed. In this study, a novel hydrogen liquefaction process integrated with a dual-pressure organic Rankine cycle (DORC) is proposed. It offers significant energy-saving by efficiently utilizing the cold energy of liquefied natural gas (LNG). The key parameters in the proposed process are investigated, and the results are combined with an improved genetic algorithm for efficient optimization of the process. The optimal exergy efficiency of the proposed process is 48.7%, and the minimal energy consumption is 6.29 kWh/kgLH2. Thanks to the power output (381.3 kW) of the DORC and the energy saved by the cryogenic compression of nitrogen (586.6 kW), energy consumption of the proposed process is reduced by approximately 3.1% compared to that of the process without a DORC. Moreover, an improved helium Brayton refrigeration cycle for hydrogen cryo-cooling is simpler, but less the refrigerant usage and energy consumption compared to the previously proposed cycles. The proposed process demonstrates excellent performance in terms of energy saving and efficiency improvement, providing a low-cost scheme to produce liquid hydrogen.

Development and modification of large-scale hydrogen liquefaction process empowered by LNG cold energy: A feasibility study

Hydrogen (H2) is considered a promising fuel and an energy carrier for carbon neutrality, but H2 has an issue in transportation and storage due to its low volumetric density. H2 liquefaction is an important technology in H2 supply that can overcome the low density issues, but the system has a serious challenge of high energy consumption. Thus, an improved energy efficient 50 ton day−1 of H2 liquefaction system comprising 4 mixed refrigeration cycles is proposed in this study. Especially, liquefied natural gas (LNG) was mainly used in the replacement of the precooling cycle, and the energy was saved by using the cold energy of LNG and generating electricity through vaporization. The specific energy consumption (SEC) of the proposed system was obtained as 3.996 kWh kg−1, however, particle swarm optimization (PSO) was implemented to increase energy efficiency of proposed process. As a result, the SEC of the optimized process was reduced to 2.917 kWh kg−1 where the LNG-cold energy control during the optimization was crucial to improve the energy efficiency. In addition, the economic and environmental feasibility were investigated. For the optimized process, the cost of the liquefied H2 (LH2) model was calculated as 1.37 $ kg-1, and 1.14 kgCO2 kg−1LH2 emissions were recorded as a result of environmental assessment. Moreover, the uncertainty analysis was implemented to assess the degree of the cost variance and the possibility of H2 production from water electrolysis was quantified. Unfortunately, electrolysis-based LH2 was hard to be economically better than steam methane reforming-based H2, however, alkaline water electrolysis-based LH2 showed the potential to overcome that of steam methane reforming in the future through technological advancement and reduction in production cost. The proposed H2 liquefaction process has a highly improved energy consumption rate, and this process can contribute to developing the H2 economy and become the potential candidate to overcome storage and transportation issues.

Design and optimization of a high-density cryogenic supercritical hydrogen storage system based on helium expansion cycle

Cryogenic supercritical hydrogen storage technology is a high-density physical hydrogen storage method, which is a highly promising hydrogen storage approach. However, existing research has mainly focused on the development of storage devices for cryogenic supercritical hydrogen, with limited research on the cooling process of supercritical hydrogen. Therefore, a novel cooling process for cryogenic supercritical hydrogen production based on helium expansion cycle with liquid nitrogen (LN2) pre-cooling is proposed in this paper. In this process, after being compressed and cooled in multiple stages, the feed hydrogen is pre-cooled by LN2. Then, cryogenic supercritical hydrogen (10 MPa, −235.15 °C, 63.36 g/L) is obtained by helium multi-stage expansion refrigeration. The process is simulated by Aspen HYSYS and optimized by genetic algorithm (GA) to obtain lower specific energy consumption (SEC). Thermodynamic analyses are conducted to evaluate the process. And compared with the conventional hydrogen liquefaction process, the results show that the proposed process is reasonable and superior. The SEC0, figure of merit (FOM), and the total exergy loss of the system are 5.432 kWh/kgH2, 43.88%, and 289.69 kW respectively. This study indicates that the proposed process has significant implications for the hydrogen industry and provides valuable information for cryogenic supercritical hydrogen storage systems.

Techno-economic-environmental assessment and AI-enhanced optimization of a gas turbine power plant with hydrogen liquefaction

Most of the power plants in the world are based on gas turbines and many researchers tried to improve their efficiencies. This goal can be attained by the optimum utilization of heat losses. The authors of the present study aim to design, model, and optimize a gas turbine-based multigeneration power plant that uses the maximum possible of input energy to boost the products capacity and improve the efficiency. To decline the hydrogen storage and transportation costs, a hydrogen liquefaction process is applied to liquified the produced hydrogen at the same time. Besides, the power plant stack containing a substantial amount of energy is employed to operate a multi-effect desalination unit. To solve the main functions of the model, a programming code is developed. Then, the objective functions of the model are optimized using a machine learning model coupled with a genetic algorithm. Sensitivity analysis reveals that the fuel mass flow rate plays a pivotal role on total cost rate and hydrogen production rate; however, does not affect the exergy efficiency. Applying such a design for heat recovery, leads to 3.27% improvement in exergy efficiency rather than similar studies. The optimization results indicates that the LCOE is declined by 8.16% and normalized emission of CO2 is mitigated by 5.82 kg/GJ.

Tapping the energy and exergy benefits of channeling liquid air energy system in the hydrogen liquefaction process

Hydrogen's low volumetric energy density challenges its role as an energy vector, especially from bulk storage and transportation viewpoint. Similar to natural gas, hydrogen liquefaction is considered the solution and way forward. The energy-intensive process typically uses liquid nitrogen as a refrigerant in the precooling cycle; however, alternative candidates have also been studied. Liquid air, which has already drawn attention as a standalone cryogenic energy-storage system, can also be a potential candidate. The discharge half-cycle of a liquid-air energy storage system is integrated as the refrigerant stream in the precooling section of the hydrogen liquefaction process. The studied scenario is part of a larger integral scheme involving multiple processes. Aspen HYSYS® v12.1 was used for the design and performance analysis of this unique concept. A process-knowledge-inspired approach was employed to optimize the design variables and realize the maximum potential benefits of the proposed integration. As a result, the total refrigerant requirement was reduced by approximately 46 % compared with the base process. Furthermore, the flexibility brought about by using equilibrium reactors helped optimize the cycle temperatures and pressures. Consequently, 42.1 % (7.88 kWh/kgLH2) less energy was consumed in the liquefaction process. The high exergy efficiency of 84.29 % indicated excellent integration and optimization. Cryogenic heat exchangers were identified as the primary sources of exergy destruction, and the coefficient of performance of the integrated process was 0.155. The concept presented and the approach adopted in this study are expected to have far-reaching outcomes and benefit the hydrogen energy network and hydrogen economy perspectives.