Thermochemical Copper-chlorine Cycle Research Articles

Investigation of the flash vaporization technique as a novel anolyte separation method in a copper-chlorine thermochemical cycle for sustainable hydrogen production

Thermochemical water-splitting processes are a promising alternative to the conventional hydrogen production technologies. In this regard, the thermochemical copper-chlorine cycle is amongst the clean hydrogen production processes that have shown immense promise to achieve commercialization in the long term future through several investigations reported in the open literature. A primary reason for this is its moderate temperature requirements which can be harnessed through a wide variety of sources such as waste heat or solar thermal energy. More specifically, the four-step variant of the copper-chlorine cycle has exhibited the highest efficiencies compared to its three and five-step versions. However, certain aspects of the cycle need further attention. One such aspect is the fourth and the final step of the cycle – the anolyte separation step which ensures the complete replenishment of all chemical compounds within the cycle. The anolyte is a homogeneous solution that constitutes water, hydrochloric acid, copper (II) chloride, and copper (I) chloride. The existing methodology for the separation of all these chemicals considers a multi-step drying process that takes place at ambient pressure and temperatures over 100°C. These conditions have been concluded to contribute to lowering the energy efficiency and increasing the cost rate of hydrogen through various studies previously conducted and published by the authors. In this regard, the authors have investigated an alternative technique for the anolyte separation process – the flash vaporization method where the partial separation of various chemical species can be achieved under vacuum conditions resulting in lower required temperatures and ultimately making the anolyte separation process relatively less energy intensive. Thus, this paper develops a stand-alone experimental set-up to investigate the flash vaporization process on a lab scale to determine its feasibility and potential to be a replacement for the existing approach of anolyte separation in a four-step copper-chlorine thermochemical cycle. The experiments are conducted under a wide variety of conditions and the obtained results are quite promising. Further, this study also considers the development of an empirical model to enable an analytical quantitative prediction of the separated anolyte solution.

Reaction kinetics and product evolution of hydrolysis in copper-chlorine thermochemical cycle for hydrogen production

By-products of the hydrolysis reaction in the copper-chlorine thermochemical cycle for hydrogen production are key to the final thermal and hydrogen efficiency. The current study focuses on the influences of reaction time, temperature, and steam partial pressure on the hydrolysis reaction and by-product formation mechanism via experimental and multiple analytical methods. The result demonstrates that the hydrolysis reaction of CuCl2 and steam converts to CuCl and Cu2OCl2, with a high conversion of 97%, while the Cu2OCl2 and CuCl2-CuO product mixtures exhibit interconversion capabilities. The increase of temperature increases the CuCl product content, while the decrease of steam partial pressure increases the by-product CuCl2. Particle morphology and reaction thermodynamics are analyzed for main and by-products formation. Finally, the homogeneous reaction model and shrinking core model are used and compared for the activation energy of the formation of Cu2OCl2 for the hydrolysis reaction and the effect of by-products.

Electricity and hydrogen production by integrating two kinds of fuel cells with copper chlorine thermo-chemical cycle

An innovative cogeneration system based on a solid oxide fuel cell (SOFC) and copper chlorine cycle is being investigated. Instead of directly making electricity by any thermodynamic cycle or thermoelectric generator, the waste heat from SOFC should be used to make hydrogen through the copper-chlorine cycle (Cu–Cl). A portable polymer exchange membrane fuel cell (PEMFC) has been suggested due to its compatibility with portable and non-portable applications. The obtained results reveal that increasing the current density of SOFC results in higher methane consumption, output power, overpotentials, and hydrogen production. Furthermore, temperature variation does not have as much influence on power generation and efficiency as current density, where the system efficiency, when operating at 0.7 A/cm2 and SOFC operating temperature of 900–1200 K, varies between 40.4 % and 46.3 %. Regarding the methane flow rate, as it increases, the output power increases as well, but the efficiency falls. The system's greatest power output is 677.5 kW and occurs at a methane flow rate of 2.13 mol/s, although the system efficiency is just 39.7 % at that point. Most importantly, SOFC generates nearly 65 % of the total power, while PEMFC generates around 35 %. Therefore, the percentage of additional power that PEMFC can produce is around 55 %.

Multi-injection downdraft moving bed reactor for hydrolysis in thermochemical hydrogen production

This paper investigates a downdraft multi-injection moving bed reactor (MBR) for the hydrolysis reaction in the copper-chlorine (Cu–Cl) thermochemical cycle for hydrogen production. The numerical modelling is conducted for a variety of system configurations of the MBR, with a focus on reducing the energy requirement of the reactor while achieving high conversion rates. Several design variables are investigated, including reactor volume, injection point location, and quantity of steam injection. The numerical predictions show an approximate 23% increase in CuCl2 conversion for the multi-injection MBR compared to a single injection design. A maximum conversion of 66.5% is predicted through design parameter variations. Asymptotic behavior for the quantity of injection locations with respect to conversion extent is presented for several different steam to copper ratios. The results and new insights in this paper suggest opportunities for conversion improvement and steam to copper ratio reduction in the hydrolysis reactor through the MBR design.

Hydrogen production using hybrid six-step copper-chlorine thermochemical cycle: Energy and exergy analyses

The hybrid thermochemical copper-chlorine (Cu–Cl) cycle for water splitting, developed as a novel approach to produce green hydrogen, has gained greater attention. A series of close-loop reactions makes the process environmentally friendly. A newly developed hybrid six-step Cu–Cl cycle consists of thermochemical, electrochemical, and a unit operation of spray drying. The present paper analyzes the configuration of the six-step Cu–Cl cycle thermodynamically. Studies on many factors are carried out to determine the cycle's total energy and exergy efficiency. The modeling and simulation of the six-step process was done by Aspen Plus. The six-step cycle was found to have an energy and exergy efficiency of 38.94 % and 52.74 %, respectively. The effect on exergetic efficiency with ambient temperature and cycle temperature variation was also investigated. The enhancement in the effectiveness of six steps Cu–Cl cycle could be possible from the current study analysis using thermal recovery and minimizing exergy destructions.

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.

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.

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.

Exergoeconomic performance evaluation of three, four, and five-step thermochemical copper-chlorine cycles for hydrogen production

Thermochemical water-splitting processes are among the most promising options for producing sustainable and green hydrogen due to being extremely environmentally benign. Being extensively investigated in the literature, the thermochemical copper-chlorine cycle has demonstrated much promise in this regard as one of the most efficient options for thermochemically obtaining hydrogen. Thus, this study focuses on investigating the exergoeconomic performances of the different variants of the copper-chlorine cycle including the three-, four-, and five-step versions. All cycles are modeled and simulated in Aspen-plus software by considering a recovery of thermal energy from industrial waste flue gases in addition to internal heat recovery. Moreover, a hydrogen production capacity of 668 kg/h is considered for all cycles. The Specific Exergy Costing methodology is employed to study the exergoeconomic performance of each cycle. All cycles are initially examined in terms of the cost rates of energy transfer and hourly levelized cost rates for each step. The cycle variants are further examined through a comparative assessment of several performance parameters including hydrogen cost rates, overall cost rates of energy transfer, and overall hourly levelized cost rates. According to the performed analyses, the three-step variant of the cycle that constitutes a high-temperature electrolysis process produces hydrogen at the lowest cost rate (0.83 $/kg) while the four-step cycle produces hydrogen at the highest cost rate (1.82 $/kg). Furthermore, the hydrolysis step is found to have the highest hourly levelized cost rates for all variants of the cycle. Several factors that impact the hydrogen cost rate are also examined comprehensively. In addition, the extent to which the hydrogen cost rate is sensitive to those factors is discussed.

Environmental impacts of a standalone solar water splitting system for sustainable hydrogen production: A life cycle assessment

Hydrogen is broadly utilized in various industries. It can also be considered as a future clean energy carrier. Currently, hydrogen is mainly produced from typical fuels such as coal; however, there exist some other clean alternatives which use water decomposition techniques. Water splitting via the copper-chlorine (Cu–Cl) thermochemical cycle is a superb option for producing clean carbon-free fuel. Here, the life cycle assessment (LCA) technique is used to investigate the environmental consequences of an integrated solar Cu–Cl fuel production facility for large-scale hydrogen production. The impact of varying important input parameters including irradiation level, plant lifetime, and solar-to-hydrogen efficiency on various environmental impacts are investigated next. For instance, an improve in the solar-to-hydrogen efficiency from 15% to 30%, results in a reduction in the GWP from 1.25 to 6.27E-01 kg CO2 eq. An uncertainty analysis using Monte Carlo simulation is conducted to deal with the study uncertainties. The results of the LCA show that the potential of acidification and global warming potential (GWP) of the current system are 8.27E-03 kg SO2 eq. and 0.91 kg CO2 eq./kg H2, respectively. According to the sensitivity analysis, the plant lifetime has the highest effect on the total GWP of the plant with a range of 0.63–1.88 kg of CO2 eq./kg H2. Results comparison with past thermochemical-based studies shows that the GWP of the current integrated system is 7% smaller than that of a solar sulfur-iodine thermochemical cycle.

A novel clean hydrogen production system combining cascading solar spectral radiation and copper-chlorine cycle: Modeling and analysis

In this work, a novel integrated hydrogen production system was proposed. A detailed analysis of the efficiency limit, energy requirement, and parametric impact was theoretically performed. The system combined cascading solar spectral radiation with a copper-chlorine thermochemical cycle, which effectively converted different grades of solar energy to clean hydrogen. The process of a four-step copper-chlorine cycle was simulated to obtain the energy demands using Aspen Plus software. A model for cascading utilization of solar spectral radiation was developed to select the optimal segmented wavelengths and investigate the effects of parameters on the system efficiency. The system designs integrated with other solar cells were also optimized using this model. Among the parameters, the segmented wavelengths were the key parameters that determined the amount of solar energy converted to heat and electricity. The theoretical calculations and simulations were used to determine the performance of this new hydrogen production system. Efficiency analysis demonstrated that the proposed system achieved an ideal efficiency of 68.20%, exceeding the theoretical limit of the single-junction photovoltaic-electrolysis water system. The efficiency of the actual design was 43.44%, higher than the systems without a spectrum splitting module. This study provides an efficient method for realizing high efficiency and high-grade solar energy cascading utilization for producing clean hydrogen energy.

Investigation of a new integrated energy system with thermochemical hydrogen production cycle and desalination

This study presents design, development and analysis of a novel integrated energy system based on renewable geothermal energy source with a Copper Chlorine (CuCl) thermochemical cycle for hydrogen production production and a multistage desalination subsystem for freshwater production. In the proposed system, five useful outputs are effectively generated, such as heat for space heating, electricity, freshwater, hot water and hydrogen. CuCl thermochemical cycle is used for hydrogen production. The need for achieving high-temperature levels for the thermochemical cycle is met by a CuCl cascaded heat pump configuration in the system. The presented system is further analyzed and assessed thermodynamically through energy and exergy approaches. A case study is conducted for the city of Vancouver, Canada. Some parametric studies are also performed to observe the effects of different ambient and working conditions for the overall system and subsystems. According to conducted thermodynamic analysis, 42.06% energy and 49.65% exergy efficiencies are obtained for the overall system. The total exergy destruction rate for the overall system components is determined to be 46.56 MW. In the CuCl-Mercury cascaded heat pump configuration, the coefficient of performance values are obtained as 1.557 for energy and 1.128 for exergy.

A standalone solar thermochemical water splitting hydrogen plant with high-temperature molten salt: Thermodynamic and economic analyses and multi-objective optimization

Alternative methods for clean production of hydrogen have been proposed recently. Some of these methods utilize water instead of hydrocarbons as the hydrogen source. The copper-chlorine (Cu–Cl) thermochemical cycle is one of the most promising methods that attracted the attention of numerous researchers and organizations in recent years. In this paper, the design and integration of a standalone solar power tower (SPT) system with LiNaK high-temperature carbonate molten salt with a four-step Cu–Cl cycle is investigated. The integrated system does not rely on external or auxiliary energy sources such as grid electricity or natural gas. The proposed system is investigated in terms of thermodynamic and economic analyses, and the system performance and hydrogen production cost are determined. For the base case, the thermal efficiencies of the Cu–Cl cycle, supercritical steam Rankine cycle, and overall system are 40.4%, 45.74%, and 28.77%, respectively. The hydrogen capacity of the system is 1530.4 kg/h, and the total capital investment is 811.04 million dollars. The levelized cost of hydrogen is estimated as $9.47/kg H2. Based on the multi-objective optimization results, the optimal system design has an overall thermal efficiency and levelized cost of hydrogen of 29.18% and $7.58/kg H2, respectively.

Synergizing hydrogen and cement industries for Canada’s climate plan – case study

ABSTRACT In December 2020, Canada released its national strengthened climate change plan with focus on cutting energy waste, cutting pollution, and build clean industrial advantage. Two weeks later, the national hydrogen strategy was announced urging all involved stakeholders to delve into the deployment of large-scale clean energy technologies. Ontario, Canada’s largest economy and leading manufacturing province, it releases its provincial hydrogen strategy and roadmap later this year. represents a viable solution for reducing CO2 emissions from large industry pollutants by integrating our innovative copper chlorine (Cu-Cl) thermochemical water splitting cycle with the energy intensive and polluting industry of cement manufacturing. The paper highlights the nexus between the production process of two valuable commodities, namely cement and Hydrogen, and the role their integration introduces for increased energy efficiency and reduction of greenhouse gas emissions. In addition, as most of the thermal energy demand in cement manufacturing is utilized during the kiln processes, the paper proposes several energy mix scenarios involving the use of hydrogen to partially meet the kiln’s heat demand. The results from these scenarios show the possibility of achieving over 15% to 19.6% reduction in CO2 emissions compared to coal-based kiln production, along with reduced recurring cost for operating the kiln. On-site large-scale hydrogen production, mixed with natural gas, was found to be financially viable and environmentally advantageous alternative to power the kilns.

An integrated bifacial photovoltaic and supercritical geothermal driven copper-chlorine thermochemical cycle for multigeneration

This study thermodynamically investigates a newly developed supercritical geothermal and solar-based integrated energy system and applies to a local community which is near Kakkonda, WD-1a geothermal plant in Shinozaki, Japan. The proposed system produces useful outputs, such as electricity, heat for space heating and freshwater for self-consumption in the community and the auxiliary systems and hydrogen for commercial purposes. Thermochemical copper-chlorine cycle, bifacial photovoltaic plant, Rankine cycle, heat pump, and multi-effect water desalination subsystems are integrated into this unique system to employ solar, geothermal, and sea sources to produce useful outputs. The overall system and its components are analyzed thermodynamically using both energetic and exergetic approaches. The parametric studies and dynamic time-dependent simulations are carried out for performance assessment. The economic comparison methods are applied to determine feasibilities. According to the calculations, 2,144.45 tons of hydrogen is produced annually. A total of 204 households is considered to consume 1235 MWh electricity, 851 MWh thermal energy and 5,314.75 tons of freshwater annually. The overall energy and exergy efficiencies are 22.7% and 18.2%, respectively, for the average ambient conditions. The unit costs of useful commodities are found to be 2.73$/kg for the hydrogen, 0.023$/kWh for the electricity, 0.015$/kWh for the thermal energy, 0.47$/m3 for the freshwater. The overall system shows 5.15 years payback period with a 22% internal rate of return. The proposed subsystems and overall system possess environmentally benign, sustainable and reliable electricity, space heating, fresh water and hydrogen production system.

Investigation of an integrated solar thermochemical plant for hydrogen production using high-temperature molten salt

One of the most promising methods for producing hydrogen is the use of a water splitting process utilising the copper-chlorine (Cu-Cl) thermochemical cycle. The Cu-Cl cycle uses heat and electricity to produce hydrogen and oxygen from the decomposition of water molecules. In this paper, a new solar-powered integrated system is proposed which utilises (LiNaK)2CO3 high-temperature carbonate molten salt as both a heat transfer fluid and a thermal energy storage medium to provide the required heat for the Cu-Cl cycle reactors and heat exchangers. The system is integrated with a supercritical regenerative steam Rankine cycle (SRC) which produces the required electricity for the electrolyser unit. Thermodynamic and economic analyses were conducted to evaluate the proposed system in terms of hydrogen production cost and system performance. For the base case, the integrated system was found to be capable of producing 823.71 kg/h of hydrogen. The system is optimised for two objective parameters, overall system thermal efficiency and the levelized cost of hydrogen. The results of optimisation analysis indicated that, for the optimal Pareto solution, the overall system thermal efficiency and levelized cost of hydrogen were 29.17%, and $7.58/kg of H2, respectively.

Energy, exergy, economic and exergoenvironmental analyses of polygeneration system integrated gas cycle, absorption chiller, and Copper-Chlorine thermochemical cycle to produce power, cooling, and hydrogen

The proposed cogeneration system consists of a gas cycle, an absorption chiller, a heat recovery steam generator (HRSG), and Copper-Chlorine (Cu-Cl) thermochemical cycle that is applied for power, cooling, and hydrogen production. The configuration of these cycles is somehow that the exhaust hot gas from the gas cycle operates a heat recovery steam generator (HRSG), which is considered to produce steam for the Cu-Cl cycle. Then, the rest of the heat of hot gas energy is recovered by an absorption chiller for producing a cooling capacity. In this cycle, minimum exhaust heat from the gas turbine delivers to the atmosphere and causes less thermal population and clean power generation. Moreover, providing cooling capacity and hydrogen production associated with this cogeneration is applicable to store hydrogen as a clean fuel. A comprehensive performance assessment of this cogeneration system has been carried out based on energy, exergy, economic, and exergoenvironmental analyses. The results revealed while energy and exergy efficiencies for the gas cycle alone are 19% and 15%, respectively, and with using this proposed plant, these values can be improved up to about 43% and 44%, respectively. Economic analysis of this system shows the simple payback period (SPP) value for the stand-alone gas cycle is about 7.2 years, whereas this index for the combined gas and Cu-Cl cycles is about 3.1 years and for the whole system is 2.4 years. The results of exergoenvironment analysis reveal that the highest exergy stability factor (exergy destruction) of 0.8 belongs to the Cu-Cl cycle and the lowest exergy stability value of about 0.03 belongs to the absorption chiller cycle.

Energy and exergy analyses of a solar-based multi-generation energy plant integrated with heat recovery and thermal energy storage systems

By the depletion of natural resources, the utilization of solar energy to provide the required needs of societies attracted many researchers across the globe. An innovative multigeneration energy system driven by solar energy is proposed in this paper. The proposed system utilizes a pressurized cavity-based solar power tower and latent thermal energy storage (TES) to continuously harness the solar energy. Considering the high-temperature nature of solar tower technology, a four-step Copper-Chlorine (Cu-Cl) thermochemical cycle is used to produce hydrogen, oxygen, and steam. Using an unfired gas turbine unit, air is used as the heat transfer fluid of the solar tower unit, instead of molten salt, to supply the required heat for the thermolysis and hydrolysis reactions of the Cu-Cl cycle. Therefore, the deficiencies of molten salts are eliminated. Moreover, recovering heat within the integrated system improves the performance of the system significantly. Also, By utilization of a high-temperature ternary eutectic phase change material (PCM), a dynamic model is developed to deal with the intermittency of solar energy. Using energy and exergy approaches, the proposed system is investigated to assess exergy destruction rates and the overall system performance. A parametric study is performed to investigate the influence of design parameters such as the number of heliostats, pressure ratio of GT, and temperatures of reactions on the system performance. The results show that the system produces electricity, steam, hydrogen, and oxygen at a rate of 41.9 MW, 12.6 kg/s, 0.19 kg/s, and 0.76 kg/s, respectively. Energy and exergy efficiencies of the integrated system are found to be 49.9%, and 44.9%, respectively. The proposed system is compared with other alternative systems available in the literature and shows the best performance among others.

P.305 The GABAA receptor positive allosteric modulator zuranolone in major depressive disorder: a double-blind, randomized, placebo-controlled phase 3 trial

In this study, an exergoeconomic analysis is performed on an integrated four-step thermochemical copper-chlorine cycle developed at the Ontario Tech. University through exergy, cost, energy, and mass (EXCEM) method. A thermodynamic model is first constructed in Aspen-plus (a process simulation software) to simulate and investigate the integrated cycle through exergy and energy analyses. The capital costs, thermodynamic loss rates, and the ratio of the thermodynamic loss rate to the capital cost of various system's components are also determined. Moreover, the average unit cost of hydrogen is evaluated and the influence of several system's parameters on the unit cost of hydrogen is analyzed. The results show that the cost of hydrogen is strongly dependent on the production capacity of the plant. Based on the analysis, our system generates hydrogen at an average unit cost of 5.54 $/kg with a plant capacity of 1619.3 kg/h considering both internal (operating and maintenance costs, etc.) and external (costs of various inputs, etc.) parameters.

Azeotropic Separation of HCl-Water by Pressure Swing Distillation: Steady State Simulation and Economic Optimization

Copper-Chlorine (Cu-Cl) thermochemical cycle for hydrogen production involves decomposition of water into hydrogen and oxygen with the use of intermediate copper and chlorine compounds and all other reactants are regenerated and recycled to create a closed loop. Our ongoing investigations on copper-chlorine (Cu-Cl) cycle involve electrochemical and thermal reactions constituting six steps. Hydrolysis of cupric chloride to copper oxide and dry hydrogen chloride (HCl) gas is one of the crucial steps. This involves non-catalytic reaction of cupric chloride and steam between 350 and 400oC which needs excess steam for complete conversion of cupric chloride thereby resulting formation of dilute hydrochloric acid rather than dry HCl gas which needs to be recycled to hydrogen generation. Therefore, azeotrope between the HCl and water needs to be eliminated. This work has proposed design and optimization of pressure swing distillation (PSD) for separation of HCl -water by using heat integration of two columns operating at different pressures and temperatures. The first column operating at low pressure concentrates the feed up to the azeotropic point and second column operating at high pressure eliminates the azeotrope and generates dry HCl gas. The reboiler heat of high pressure column (HPC) is reutilized to heat the low pressure column (LPC) and HPC feed which reduces the total annual cost (TAC). Heat integration saves an energy cost by 11.03% of and total annual cost by 6.83 % as compared to non-heat integrated PSD system. Feed composition has strong impact on energy and ultimately economics.