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Economically feasible and optimized process development for the commercialization of liquid hydrogen (LH 2) is vital because the cooling system of a H 2 liquefaction setup requires considerable energy. Liquefied natural gas (LNG) cold energy can be used for H 2 liquefaction to facilitate efficient production of LH 2. In this study, we evaluated three scenarios of a novel H 2 liquefaction process at a scale of 300 tons/day utilizing LNG cold energy. Subsequently, a comparative study of the energy analysis, economic evaluation, and environmental evaluation was conducted. Among the three scenarios, the scenario that used LNG cold energy directly had the lowest minimum selling price (MSP) and environmental impact. The discounted cash flow rate of return for this project was 12.98%. Our results demonstrated that the use of LNG cold energy can improve the economic and environmental feasibility of H 2 liquefaction. [Display omitted] • H 2 is an environmentally safe and sustainable fuel that can replace fossil fuels. • Liquid H 2 overcomes the storage and transport limitations of gaseous hydrogen. • Using liquefied natural gas (LNG) cold energy produces liquid H 2 efficiently. • Using LNG cold energy can improve the feasibility of hydrogen liquefaction. [ABSTRACT FROM AUTHOR]

Nuclear assisted low carbon hydrogen production by water electrolysis represents a potential application of nuclear cogeneration towards deep decarbonization of several fossil fuel-dependent industrial sectors. This work builds a probabilistic techno-commercial model of a water electrolysis plant coupled to an existing nuclear reactor for base load operations. The objective is to perform discounted cash flow (DCF) calculations for levelized nuclear hydrogen production cost under input parameter uncertainty. The probability distributions of inputs are used with the Monte Carlo-Latin Hypercube (MC-LH) sampling technique to generate 105 input scenarios and corresponding distribution of the levelized or life cycle hydrogen production cost instead of deterministic point values. Based on current techno-economic conditions, the levelized production costs of electrolytic hydrogen using electricity from large water-cooled nuclear reactors are determined to be US $ 12.205 ± 1.342, 8.384 ± 1.148 and 6.385 ± 1.051/kg H 2 respectively at rated alkaline water electrolyser capacities of 1.25 MW(e), 2.5 MW(e) and 5 MW(e). The corresponding values for PEM water electrolysers are US $ 13.162 ± 1.356, 8.891 ± 1.141 and 6.663 ± 1.057/kg H 2. The potential for flexible nuclear reactor operation and management of power demand uncertainties through nuclear hydrogen cogeneration is also examined through a case study. [ABSTRACT FROM AUTHOR]

A large-scale hydrogen supply chain is an alternative for the transportation of energy generated from a renewable energy source. Utilizing this technology would drastically improve the generation of clean energy. Therefore, an analysis method to estimate the economic and environmental benefits of the introduction of a hydrogen supply chain using an existing pipeline is developed. The proposed method first estimates the energy and exergy flows in the system to calculate the overall efficiency of these quantities. Afterward, the payback period is estimated based on the overall energy efficiency using the discounted cash flow (DCF) method. The overall efficiency of the system, based on the energy analysis presented, would seem to be the final delivered electrical, fuel and useable heat energy delivered to end use divided by the input solar and wind energy. Furthermore, the environmental effects due to the introduction of the systems are evaluated considering the reduction of global warming and air pollution gases, such as CO 2 and PM2.5. The proposed analysis method was applied considering a natural gas pipeline that connects Qinghai and Shanghai. As a result, conversion ratios of 24.9% for electricity and 17.5% for heat were achieved, with the overall efficiency of the system of 42.4% based on the electricity obtained from photovoltaics. 3.02 Gt of CO 2 , 104 kt of SO x , and 134 kt of NO x , which represent 3.3%, 0.5%, and 0.6% of the annual discharge in China, respectively, and 8.66 kt of PM2.5 would be reduced every year. Furthermore, a reduction of 953 Mt in coal consumption is expected. The payback period of the proposed system using the DCF method is 4.17 and 2.28 years for the two alternatives evaluated in this work. The cash flow of the DCF is influenced by installation cost and operation cost of equipment. • Introductory method of a hydrogen supply chain using gas pipeline was shown. • Economic and environmental benefits were clarified from the energy flow. • Potentiality of a large-scale clean energy using hydrogen was suggested. • Gas pipeline currently installed between Qinghai and Shanghai was analyzed. [ABSTRACT FROM AUTHOR]

Green ammonia production is facing increasing interest on a global scale as a hydrogen carrier for power generation as well as fertilizer for food production. The conventional Haber-Bosch method for ammonia synthesis is energy demanding, requires high purity hydrogen, and is based on fossil fuels. A preliminary techno-economic model for electrochemical ammonia synthesis at near ambient pressure using feed rates of 32 metric ton/day for hydrogen and 135 metric ton/day for nitrogen is presented in this study. Various pathways using different methods for nitrogen generation and hydrogen production were investigated to gain insight into added energy savings per metric ton of ammonia. Electrochemical synthesis using electrolysis for hydrogen and cryogenic nitrogen was found to be a potentially viable pathway for green ammonia. The profitability metrics including discounted cash flow rate of return, net present value and discounted payback period were estimated to be 8%, $40 MM, and 4–6 years respectively for this pathway. The cost of electricity, conversion rate, and conversion efficiency dominate the tonnage cost of ammonia and were used to assess the feasibility of the model. A life cycle assessment was also conducted to assess the environmental impact of a well to product ammonia process. • Integrated electrochemical ammonia systems with renewable intermittent sources has. linear scalability advantages. • Energy consumption of at least 17 MWh per metric ton for electrochemical ammonia. • Number of modules decreases with current density. • Specific energy decreases as the production rate increases. [ABSTRACT FROM AUTHOR]

Abstract One of the main challenges associated with utilisation of the renewable energy is the need for energy storage to handle its intermittent nature. Power-to-Gas (PtG) represents a promising option to foster the conversion of renewable electricity into energy carriers that may attend electrical, thermal, or mechanical needs on-demand. This work aimed to incorporate a stochastic approach (Artificial Neural Network combined with Monte Carlo simulations) into the thermodynamic and economic analysis of the PtG process hybridized with an oxy-fuel boiler (modelled in Aspen Plus®). Such approach generated probability density curves for the key techno-economic performance indicators of the PtG process. Results showed that the mean utilisation of electricity from RES, accounting for the chemical energy in SNG and heat from methanators, reached 62.6%. Besides, the probability that the discounted cash flow is positive was estimated to be only 13.4%, under the set of conditions considered in the work. This work also showed that in order to make the mean net present value positive, subsidies of 68 €/MW el h are required (with respect to the electricity consumed by PtG process from RES). This figure is similar to the financial aids received by other technologies in the current economic environment. Highlights • Stochastic approach to assess economics of Power to Gas-Oxycombustion system. • Inputs variables uncertainty to have energy and economy accurate results. • PtG reaches on average an efficiency of 62.6% LHV. • Governmental support required to make PtG processes economically feasible. [ABSTRACT FROM AUTHOR]