Application of a multicriteria methodology for evaluation of energy alternatives for hydrogen production for the automotive sector – Case study

This paper presents a case study focusing on fourteen most used energy alternatives in Brazil, possible to feed large scale hydrogen production plants for the automotive sector. The evaluations are made using a Decision Making Support Method, MACBETH - Measuring Attractiveness by a Categorical Based Evaluation Technique, with the computational code M-MACBETH 3.2.0, using criteria that include economic and financial, technological, environmental and social aspects. The selected criteria that were used in the assessment, for each of the energy alternatives are capital to be invested in a plant, leveled cost of electric energy produced, CO₂ emissions, mortality rate due to the technology use and energy efficiency of technology. The main results obtained showed that photovoltaics off grid electric energy is the most attractive alternative, followed by the photovoltaic on grid alternative, for an eventual automotive hydrogen program in Brazil.     

Regional energy system optimization – Potential for a regional heat market

Energy supply companies and industrial plants are likely to face new situations due to, for example, the introduction of new energy legislation, increased fuel prices and increased environmental awareness. These new prerequisites provide companies with new challenges but also new possibilities from which to benefit. Increased energy efficiency within companies and increased cooperation between different operators are two alternatives to meet the new conditions. A region characterized by a high density of energy-intensive processes is used in this study to find the economic potential of connecting three industrial plants and four energy companies, within three local district heating systems, to a regional heat market, in which different operators provide heat to a joint district heating grid. Also, different investment alternatives are studied. The results show that the economical potential for a heat market amounts to between 5 and 26 million EUR/year with payback times ranging from two to eleven years. However, the investment costs and the net benefit for the total system need to be allotted to the different operators, as they benefit economically to different extents from the introduction of a heat market. It is also shown that the emissions of CO₂ from the joint system would decrease compared to separate operation of the systems. However, the valuation of CO₂ emissions from electricity production is important as the difference of emitted CO₂ between the accounting methods exceeds 650 kton/year for some scenarios.     

High-temperature electrolysis for large-scale hydrogen production from nuclear energy – Experimental investigations

The Idaho National Laboratory (INL) is currently assessing the feasibility of using solid-oxide based electrolysis cell technology for high temperature electrolysis of steam for large-scale hydrogen production. In parallel, the INL is studying the simultaneous electrolysis of steam and carbon dioxide for syngas (hydrogen/carbon monoxide mixture) production. When linked to a nuclear power source, this technology provides a carbon neutral means of producing syngas while consuming CO₂. The scope of experimental investigations at the INL includes single button cell tests, multi-cell stacks, and multi-stack systems. Multi-cell stack testing used 10 cm × 10 cm (8 cm × 8 cm active area) or 20 cm × 20 cm (18 cm × 18 cm active area) planar cells supplied by Ceramatec, Inc (Salt Lake City, Utah, USA). Multi-stack testing encompassed up to 720 10 cm × 10 cm cells and was conducted in a newly developed 15 kW Integrated Laboratory Scale (ILS) test facility. Gas composition, operating voltage, and operating temperature were varied during testing. The tests were heavily instrumented, and outlet gas compositions were monitored with a gas chromatograph. Results to date show the process to be a promising technique for large-scale hydrogen and syngas production.     

Waste to energy – An evaluation of the environmental impact

The thermal treatment of waste with the heat recovery (Waste to Energy – WTE) provides us with clean and reliable energy in the form of heat as well as power. This has contributed to primary energy savings in conventional utility systems. Impact of WTE regarding the environmental issue is quantified in this paper. The evaluation focuses on the calculation of primary energy savings. A novel methodology is proposed. Then an assessment of the emission rate is made and results discussed. Real up-to-date municipal solid waste incinerator with nominal capacity 100 kt/y is involved in a case study. Benefit of its operation has been compared with other up-to-date utility concepts.     

Hydrogen as an export commodity – Capital expenditure and energy evaluation of hydrogen carriers

In this paper, we describe a case-study exploring the use of 600 MW of power from New Zealand's Manapouri Power Station to produce hydrogen for export via water electrolysis. Three H₂ carriers were considered: liquid H₂, ammonia, and toluene hydrogenation/methylcyclohexane dehydrogenation. Processes were simulated in Aspen's HYSYS for each of the carriers to determine their associated energy and annualised capital expenditure costs. We found that the total capital investment for all carriers was surprisingly consistent, but with quite different splits between the electrolysis and carrier formation plants. Based on our analysis the energy availability for liquid H₂ ranged from 53.9 to 60.7% depending on the energy cost associated with cryogenic H₂ liquefaction. The energy availability for liquid ammonia was 37.5% after conversion back to H₂, or 53.6% if the ammonia can be used directly as a fuel. For toluene/methylcyclohexane the energy availability was 41.2%. The total of the electricity and annualised capital costs per kg of H₂ ranged from NZ$5.63 to NZ$6.43 for liquid H₂, NZ$6.24 to NZ$8.91 for ammonia and was NZ$7.86 for toluene/methylcyclohexane, using a net electricity cost of NZ$70/MWh. The cost of hydrogen (or energy in the case of direct use ammonia) was more strongly influenced by the efficiency of energy retention than on capital investment, as the electricity costs contributed approximately two thirds of total costs. In the long-term, liquid hydrogen looks to be the most versatile H₂ carrier, but significant infrastructure investment is required.     

Determining parameters of heat exchangers for heat recovery in a Cu–Cl thermochemical hydrogen production cycle

A heat exchanger is a device built for efficient heat transfer from one medium to another. Shell and tube heat exchangers are separated wall heat exchangers and are commonly used in the nuclear and process industry. The CuCl cycle is used to thermally crack water in to H₂ and O₂. The present study presents the heat exchanger thermal design using analysis of variance for heat recovery from oxygen at 500 °C, coming from the molten salt reactor. Polynomial regressions in terms of the amount of chlorine in the oxygen, the mass flow rate on the tube side, and the shell's outlet temperature are estimated for various exchanger parameters and the results are compared with the bell Delaware method. Based on energy and exergy analysis, this study also discusses the best possible path for the recovered heat from oxygen. Optimal heat exchanger parameters are estimated by Design-Expert^® Stat-Ease for most effective heat recovery.     

Electrodeposited laser – nanostructured electrodes for increased hydrogen production

In the present work, a novel approach has been employed to effectively enlarge the electrocatalytic area of the electrodes in an alkaline electrolysis setup. This approach consists of a two-step electrode fabrication process: In the first step, ultrashort laser pulses have been used to nanostructure the electrode surface. In the second step, electrodeposition of nickel particles was performed in a modified Watt's bath. The resulting electrodes have been found to exhibit a significantly increased hydrogen evolution reaction (HER) activity. Compared to the laser-nanostructured electrode (LN) and an untreated (i.e., flat) electrode, the electrodeposited-laser-nanostructured (ELN) electrode provides (i) enhanced electrochemical values (ii) a significant increase of double-layer capacitance (C_DL) (values up to 1945 μF cm^?2) compared to that of an LN electrode (288 μF cm^?2) (iii) higher J_peaks at CVs sweeps and (iv) lower Tafel slopes (?121 mV dec^?1 compared to ?157 mv dec^?1). The ELN electrode provides an overpotential value of |η|₁₀₀ = 264 mV, which shows a noteworthy 34% decrease compared to a flat Ni electrode and a 15% decrease to an (LN) electrode. Scanning electron microscopy (SEM) revealed that the electrodeposition of nickel on the LN nickel electrodes results in a dendrite-like morphology of the surface. Thus, the enhancement of the HER has been attributed to the dendrite-like geometry and the concomitant enlargement of the electrocatalytic area of the electrode, which presents an electrochemical active surface area (ECSA) = 97 cm^?2 compared to 2.8 cm^?2 of the flat electrode. The electrodes have also been tested in actual hydrogen production condition, and it was found that the ELN electrode produces 4.5 times more hydrogen gas than a flat Ni electrode and 20% more hydrogen gas than an LN electrode (i.e. without the extra nickel electrodeposition).     

High-temperature electrolysis for large-scale hydrogen and syngas production from nuclear energy – summary of system simulation and economic analyses

A research and development program is under way at the Idaho National Laboratory (INL) to assess the technological and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for efficient high-temperature hydrogen production from steam. This work is supported by the US Department of Energy, Office of Nuclear Energy, under the Nuclear Hydrogen Initiative. This paper will provide an overview of large-scale system modeling results and economic analyses that have been completed to date. System analysis results have been obtained using the commercial code UniSim, augmented with a custom high-temperature electrolyzer module. Economic analysis results were based on the DOE H2A analysis methodology. The process flow diagrams for the system simulations include an advanced nuclear reactor as a source of high-temperature process heat, a power cycle and a coupled steam electrolysis loop. Several reactor types and power cycles have been considered, over a range of reactor outlet temperatures. Pure steam electrolysis for hydrogen production as well as coelectrolysis for syngas production from steam/carbon dioxide mixtures have both been considered. In addition, the feasibility of coupling the high-temperature electrolysis process to biomass and coal-based synthetic fuels production has been considered. These simulations demonstrate that the addition of supplementary nuclear hydrogen to synthetic fuels production from any carbon source minimizes emissions of carbon dioxide during the production process.     

Regulatory failures for nuclear safety – the bad example of Japan – implication for the rest of world

Investigation before and after the Fukushima nuclear accident has revealed that the failures of Japan's nuclear regulatory system was also blame to the worst nuclear accident since Chernobyl. The Fukushima nuclear accident has served to remind us that nuclear safety regulatory failure is vulnerable to the potentially deadly combination of natural risk. It should be noted that nuclear regulatory failures are not unique to Japan, given the low efficiency of the International Atomic Energy Agency (IAEA). We are living in a nuclear world. We have no alternative but to learn the lessons from the Fukushima. Unfortunately, all signs do not seem to be promising. This was partly due to competing proposals from several countries without clear understanding of which ideas would help, and a lack of sustained leadership focused on building support for key initiatives beforehand. New actions to strengthen the nuclear safety should be derived upon a thorough assessment of the causes for Japan's nuclear regulatory failures, as well as a comparative analysis of the nuclear regulatory systems in Japan, the United States (the owner of most nuclear reactors in operation), and China (the owner of most nuclear reactors under construction). This article is addressed to conduct an analysis of the causes for Japan's nuclear regulatory failure, discuss the key deficits in the nuclear regulatory systems of the U.S. and China, and finally outline two main policy recommendations. Nuclear accident knows no boundaries. Strengthening our nuclear safety regulation is not an option but an imperative, thus ensuring that the 433 operational units of reactor run safely, as well as 65 proposed ones. March 11, 2012 is the first anniversary of the Fukushima accident. This provocative article that calls for action on upgrade nuclear safety regulation over the world is dedicated to commemorate the first anniversary of the Fukushima accident.     

Environmental evaluation of hydrogen production employing innovative chemical looping technologies – A Romanian case study

A cradle-to-gate life cycle assessment is carried out to evaluate the environmental impact of producing 1 kg of hydrogen implementing innovative chemical looping technologies: chemical looping hydrogen production (CLH), sorption enhanced reforming (SER), and sorption enhanced chemical looping reforming (SECLR). The performance of the looping technologies is compared against conventional hydrogen production without and with CO₂ capture, as well as against green hydrogen production in order to determine the more environmentally-friendly option. Comparing the looping technologies with the reference blue hydrogen production it shows that CLH has a lower environmental burden, presenting smaller values in 9 out of 12 environmental impact indicators. If we confront the looping technologies against each other, CLH shows better performance in 11 out of 12 environmental indicators. As expected, green hydrogen has a much smaller overall environmental impact with the exception of human toxicity, terrestrial ecotoxicity and mineral depletion.     

Fusion energy : An energy source of the future?

With an increasing world population and a growing economy, the demand for energy is sure to grow. The latest predictions for world energy demand all show an upward trend and even with increased energy efficiency we will still need substantially more energy by 2050 than we use today. Where's it to come from? Dr Federico Casci of the European Fusion Development Agreement (EFDA) organisation believes part of the answer is fusion…     

Novel thermoelectric generator heat exchanger for indirect heat recovery from molten CuCl in the thermochemical Cu–Cl cycle of hydrogen production

The looming threat of global warming has elicited efforts to develop reliable sustainable energy resources. Hydrogen as a clean fuel is deemed a potential solution to the problem of storage of power from renewable energy technologies. Among current thermochemical hydrogen generation methods, the thermochemical copper-chlorine (Cu–Cl) cycle is of high interest owing to lower temperature requirements. Present study investigates a novel heat exchanger comprising a thermoelectric generator (TEG) to recover heat from high temperature molten CuCl exiting the thermolysis reactor. Employing casting/extrusion method, the performance of the proposed heat exchanger is numerically examined using COMSOL Multiphysics. Results indicate that maximum generated power could exceed 40 W at the matching current of 4.5 A. Maximum energy conversion efficiency yields to 7.1%. Results demonstrate that TEG performance boosts with increasing the inlet Re number, particularly at the hot end. For the molten CuCl chamber, findings denote that there is a 36% discrepancy between highest and lowest Re numbers. Similarly, the highest efficiency value pertains to the case with the highest inlet velocity. Moreover, the highest temperature difference between inlet and outlet of the cooling water is about 28 °C and 10 °C for the lowest and highest inlet Re numbers, respectively. Average deviation from anticipated friction factor and Nusselt number are 0.31% and 12.62%, respectively.     

Technoeconomics of large-scale clean hydrogen production – A review

Hydrogen is widely used in many industries, yet its role in the clean energy transition goes beyond being an element of these industries. Near-term practical large-scale clean hydrogen production can be made available by involving nuclear, solar, and other renewable energy sources in the process of hydrogen production, and coupling their energy systems to sustainable carbon-free hydrogen technologies. This requires further investigation and assessment of the different alternatives to achieve clean hydrogen using these pathways. This paper assesses the technoeconomics of promising hydrogen technologies that can be coupled to nuclear and solar energy systems for large-scale hydrogen production. It also provides an overview of the design, status and advances of these technologies.     

Carbon – Zn hydrotalcite hybrid catalyst for fermentative hydrogen production

The activities of modified hydrotalcite (HT) with Zn catalysts supported on treated activated carbon (Zn-HT/TAC) were carried out in batch fermentations for their potential enhancement of fermentative hydrogen production. The hybrid catalyst of Zn-HT/TAC was synthesized by the incipient impregnation method. The hydrogen production profiles showed that the initial activity of a combined-function of Zn-HT/TAC and co-addition of Zn-HT and TAC were more active than the individual catalysts with 50% and 85% increment of hydrogen production, as compared to the control, respectively. At the final stage, the maximum hydrogen yield obtained at 8.33 g/L of Zn-HT/TAC was 3.08 mol H₂/mol sucrose with a 26.62% increment as compared to the control. The Zn-HT/TAC deactivated after 360 h with Mg²⁺ and Zn²⁺ ions leaching and saturation adsorption. The performance of the resulting hybrid catalyst was observed to be a function of cooperative effects related to the base property of Zn-HT and selective adsorption of TAC.     

Plant sizing and evaluation of hydrogen production costs from advanced processes coupled to a nuclear heat source. Part I: Sulphur–iodine cycle

Hydrogen demand is already strong. It should significantly increase in the next few years due to the refinery industry's growing needs and new applications such as synthetic fuel or biofuel production. To meet the demand, advanced processes are being developed throughout the world in a sustainability context. Among the most studied ones are thermochemical cycles: the sulphur–iodine and hybrid-sulphur cycles.     

Flexibility improvement evaluation of hydrogen storage based on electricity–hydrogen coupled energy model

To achieve carbon neutrality by 2060, decarbonization in the energy sector is crucial. Hydrogen is expected to be vital for achieving the aim of carbon neutrality for two reasons: use of power-to-hydrogen (P2H) can avoid carbon emissions from hydrogen production, which is traditionally performed using fossil fuels; Hydrogen from P2H can be stored for long durations in large scales and then delivered as industrial raw material or fed back to the power system depending on the demand. In this study, we focus on the analysis and evaluation of hydrogen value in terms of improvement in the flexibility of the energy system, particularly that derived from hydrogen storage. An electricity–hydrogen coupled energy model is proposed to realize the hourly-level operation simulation and capacity planning optimization aiming at the lowest cost of energy. Based on this model and considering Northwest China as the region of study, the potential of improvement in the flexibility of hydrogen storage is determined through optimization calculations in a series of study cases with various hydrogen demand levels. The results of the quantitative calculations prove that effective hydrogen storage can improve the system flexibility by promoting the energy demand balance over a long term, contributing toward reducing the investment cost of both generators and battery storage and thus the total energy cost. This advantage can be further improved when the hydrogen demand rises. However, a cost reduction by 20% is required for hydrogen-related technologies to initiate hydrogen storage as long-term energy storage for power systems. This study provides a suggestion and reference for the advancement and planning of hydrogen storage development in regions with rich sources of renewable energy.     

Effect of internal void placement on the heat transfer performance – Encapsulated phase change material for energy storage

The effect of an internal air void on the heat transfer phenomenon within encapsulated phase change material (EPCM) is examined. Heat transfer simulations are conducted on a two dimensional cylindrical capsule using sodium nitrate as the high temperature phase change material (PCM). The effects of thermal expansion of the PCM and the buoyancy driven convection within the fluid media are considered in the present thermal analysis. The melting time of three different initial locations of an internal 20% air void within the EPCM capsule are compared. Latent heat is stored within an EPCM capsule, in addition to sensible heat storage. In general, the solid/liquid interface propagates radially inward during the melting process. The shape of the solid liquid interface as well as the rate at which it moves is affected by the location of the internal air void. The case of an initial void located at the center of the EPCM capsule has the highest heat transfer rate and thus fastest melting time. An EPCM capsule with a void located at the top has the longest melting time. Since the inclusion of a void space is necessary to accommodate the thermal expansion of a PCM upon melting, understanding its effect on the heat transfer within an EPCM capsule is necessary.     

Hydrocarbon plant—New source of energy for future

The development of alternative sources for energy and chemicals, particularly the use of plant biomass as a renewable source for fuel or chemical feedstocks, has received much recent attention. This paper attempts to review the work carried out by many workers on evaluation of some plant materials as source of energy and chemical feedstocks and the possibilities of producing hydrocarbon and related chemical products, directly or indirectly. Also an exploratory work carried out at Regional Research Laboratory, Jorhat is discussed. Some future directions, which need to be considered to promote development of these petrocrops, are suggested.     

Enhancement of energy generation efficiency in industrial facilities by SOFC – SOEC systems with additional hydrogen production

Industry is one of the highest energy consumption sector: some facilities like steelworks, foundries, or paper mills are highly energy-intensive activities. Many countries have already implemented subsidies on energy efficiency in generation and utilisation, with the aim of decreasing overall consumption and energy intensity of gross domestic product. Meanwhile, researchers have increased interest into alternative energy systems to decrease pollution and use of fossil fuels. Hydrogen, in particular, is proposed as a clean alternative energy vector, as it can be used as energy storage mean or to replace fossil fuels, e.g. for transport.This work analyses the re-vamping of the energy generation system of a paper mill by means of reversible solid oxide cells (RSOCs). The aim is not only to increase efficiency on energy generation, but also to create a polygeneration system where hydrogen is produced. Application on a real industrial facility, based in Italy with a production capacity of 60000 t/y of paper, is analysed. First, the current energy system is studied. Then, a novel system based on RSOC is proposed. Each component of the systems (both existing and novel) is defined using operational data, technical datasheet, or models defined with thermodynamic tools. Then, the interaction between them is studied. Primary energy analysis on the novel system is performed, and saving with respect to the current configuration is evaluated. Even if the complexity of the system increases, results show that saving occurs between 2 and 6%. Hydrogen generation is assessed, comparing the RSOC integrated system with proton exchange membrane (PEM) electrolysis, in terms of both primary energy and economics. Results exhibit significant primary energy and good economic performance on hydrogen production with the novel system proposed (hydrogen cost decreases from 10 €/kg to at least 8 €/kg).     

Salt domes in Poland – Potential sites for hydrogen storage in caverns

Salt bearing formations have world-wide distribution. The geological structures of Permian salt bearing deposits in Poland are similar to those in the other parts of the Central European salt basin, to which they belong as its SE part. There is a notable trend to use salt domes as sites for underground storage of various gases, fuels and other substances, including hydrogen. Possibilities of using salt domes in Poland for underground hydrogen storage are presented with the focus on the option of using the underground space for energy storage. Usefulness of the 27 hitherto studied salt domes in the Polish Lowlands for underground hydrogen storage in caverns is evaluated using analytical methods of the geology of mineral deposits.Seven not yet developed salt domes are selected as the most promising ones, taking into account geological and reservoir criteria: Rogó?no, Damas?awek, Lubień, ?ani?ta, Goleniów, Izbica Kujawska and D?bina. Initial experience in underground hydrogen storage in salt caverns is presented. Geological conditions favourable for hydrogen storage in underground caverns leached in salt domes are outlined. Their advantage relative to underground storage sites in porous rocks (depleted hydrocarbon deposits and deep aquifers) is discussed.