Applications & Pathways

The issue of depleting fossil fuels has emphasized the use of renewable energy. Multigeneration systems fueled by renewables such as geothermal biomass solar etc. have proven to be cutting-edge technologies for the production of different valuable by-products. This study proposes a multigeneration system using a geothermal source of energy. The main outputs include power space heating cooling fresh and hot water dry air and hydrogen. The system includes a regenerative Rankine cycle a double effect absorption cycle and a double flash desalination cycle. A significant amount of electrical power hydrogen and fresh water is generated which can be used for commercial or domestic purposes. The power output is 103 MW. The thermal efficiency is 24.42% while energetic and exergetic efficiencies are 54.22% and 38.96% respectively. The COPen is found to be 1.836 and the COPex is found to be 1.678. The hydrogen and fresh water are produced at a rate of 0.1266 kg/s and 37.6 kg/s respectively.

The fuel-cell electric vehicle (FCEV) has been defined as a promising way to avoid road transport greenhouse emissions but nowadays they are not commercially available. However few studies have attempted to monitor the global scientific research and technological profile of FCEVs. For this reason scientific research and technological development in the field of FCEV from 1999 to 2019 have been researched using bibliometric and patent data analysis including network analysis. Based on reports the current status indicates that FCEV research topics have reached maturity. In addition the analysis reveals other important findings: (1) The USA is the most productive in science and patent jurisdiction; (2) both Chinese universities and their authors are the most productive in science; however technological development is led by Japanese car manufacturers; (3) in scientific research collaboration is located within the tri-polar world (North America–Europe–Asia-Pacific); nonetheless technological development is isolated to collaborations between companies of the same automotive group; (4) science is currently directing its efforts towards hydrogen production and storage energy management systems related to battery and hydrogen energy Life Cycle Assessment and greenhouse gas (GHG) emissions. The technological development focuses on technologies related to electrically propelled vehicles; (5) the International Journal of Hydrogen Energy and SAE Technical Papers are the two most important sources of knowledge diffusion. This study concludes by outlining the knowledge map and directions for further research.

Locomotives still use antiqued engines such as internal combustion engines operated by fossil fuels which cause global warming due to their significant emissions. This paper continues investigating the newly hybridized locomotive engine containing a gas turbine system solid oxide fuel cell system energy saving system and on-board hydrogen production system. This new engine is operated using five fuel blends composed of five alternative fuels such as hydrogen methane methanol ethanol and dimethyl ether. The current investigation involves exergy analysis exergo-economic analysis and exergo-environmental analysis to assess the engine from three perspectives: efficiency/irreversibility cost and environmental impact. The study results show that the net power of this new engine is 4948.6 kW and it has an exergetic efficiency of 62.7% according to the fuel and product principle. This engine weighs about 9 tons and costs about $10.2M with a levelized cost rate of 147 $/h and 14.06 mPt/h of overall component-related environmental rate. The average overall specific fuel and product exergy costs are about 37 $/GJ and 60 $/GJ and the minimum values are 13.3 $/GJ and 21.8 $/GJ using methane and hydrogen blend respectively. Also the average overall specific fuel and product exergo-environmental impact are about 15 and 23 mPt/MJ respectively. The on-board hydrogen production has an average exergy cost of 274 $/GJ and an environmental impact of 52 mPt/MJ. Hydrogen blended with methane or methanol is found to be more economic and has less environmental impact.

With rising temperatures extreme weather events and environmental challenges there is a strong push towards decarbonization and an emphasis on renewable energy with wind energy emerging as a key player. The concept of multi-energy systems offers an innovative approach to decarbonization with the potential to produce hydrogen as one of the output streams creating another avenue for clean energy production. Hydrogen has significant potential for decarbonizing multiple sectors across buildings transport and industries. This paper explores the integration of wind energy and hydrogen production particularly in areas where clean energy solutions are crucial such as impoverished villages in Africa. It models three systems: distinct configurations of micro-multi-energy systems that generate electricity space cooling hot water and hydrogen using the thermodynamics and cost approach. System 1 combines a wind turbine a hydrogen-producing electrolyzer and a heat pump for cooling and hot water. System 2 integrates this with a biomass-fired reheat-regenerative power cycle to balance out the intermittency of wind power. System 3 incorporates hydrogen production a solid oxide fuel cell for continuous electricity production an absorption cooling system for refrigeration and a heat exchanger for hot water production. These systems are modeled with Engineering Equation Solver and analyzed based on energy and exergy efficiencies and on economic metrics like levelized cost of electricity (LCOE) cooling (LCOC) refrigeration (LCOR) and hydrogen (LCOH) under steady-state conditions. A sensitivity analysis of various parameters is presented to assess the change in performance. Systems were optimized using a multiobjective method with maximizing exergy efficiency and minimizing total product unit cost used as objective functions. The results show that System 1 achieves 79.78 % energy efficiency and 53.94 % exergy efficiency. System 2 achieves efficiencies of 55.26 % and 27.05 % respectively while System 3 attains 78.73 % and 58.51 % respectively. The levelized costs for micro-multi-energy System 1 are LCOE = 0.04993 $/kWh LCOC = 0.004722 $/kWh and LCOH = 0.03328 $/kWh. For System 2 these values are 0.03653 $/kWh 0.003743 $/kWh and 0.03328 $/kWh. In the case of System 3 they are 0.03736 $/kWh 0.004726 $/kWh and 0.03335 $/kWh and LCOR = 0.03309 $/kWh. The results show that the systems modeled here have competitive performance with existing multi-energy systems powered by other renewables. Integrating these systems will further the sustainable and net zero energy system transition especially in rural communities.

Power-to-Methane as one part of Power-to-Gas has been recognized globally as one of the key elements for the transition towards a sustainable energy system. While plants that produce methane catalytically have been in operation for a long time biological methanation has just reached industrial pilot scale and near-term commercial application. The growing importance of the biological method is reflected by an increasing number of scientific articles describing novel approaches to improve this technology. However these studies are difficult to compare because they lack a coherent nomenclature. In this article we present a comprehensive set of parameters allowing the characterization and comparison of various biological methanation processes. To identify relevant parameters needed for a proper description of this technology we summarized existing literature and defined system boundaries for Power-to-Methane process steps. On this basis we derive system parameters providing information on the methanation system its performance the biology and cost aspects. As a result three different standards are provided as a blueprint matrix for use in academia and industry applicable to both biological and catalytic methanation. Hence this review attempts to set the standards for a comprehensive description of biological and chemical methanation processes.

With increasing penetration of renewable energy it is important to source adequate system flexibility to maintain security of supply and minimize renewable generation curtailment. Power to hydrogen (P2H) plays an important role in the low-carbon renewable dominated energy systems. By blending green hydrogen produced from renewable power into the natural gas pipelines it is possible to help integrate large-scale intermittent generation and smooth the variability of renewable power output through the interconnection of the natural gas network hydrogen energy network and electric network. A two-stage stochastic mixed-integer nonlinear planning framework for P2H sizing and siting is proposed in this paper considering system flexibility requirements. The problem is then reduced to a mixed-integer second-order cone (MISOC) model through convex transformation techniques in order to reduce the computation burden. Then a distributed algorithm based on Bender’s decomposition is applied to obtain the optimal solution. A modified hybrid IEEE 33-node and Gas 20-node system is then used for simulation tests. The results showed that investment of P2H can significantly reduce the total capital and operational costs with lower renewable generation curtailment and electricity demand shedding. Numerical tests demonstrated to demonstrate the validity of the proposed MISOC model.

An increasing demand in the marine industry to reduce emissions led to investigations into more efficient power conversion using fuels with sustainable production pathways. Solid Oxide Fuel Cells (SOFCs) are under consideration for long-range shipping because of its high efficiency low pollutant emissions and fuel flexibility. SOFC systems also have great potential to cater for the heat demand in ships but the heat integration is not often considered when assessing its feasibility. This study evaluates the electrical and heat efficiency of a 100 kW SOFC system for marine applications fuelled with methane methanol diesel ammonia or hydrogen. In addition cathode off-gas recirculation (COGR) is investigated to tackle low oxygen utilisation and thus improve heat regeneration. The software Cycle Tempo is used to simulate the power plant which uses a 1D model for the SOFCs. At nominal conditions the highest net electrical efficiency (LHV) was found for methane (58.1%) followed by diesel (57.6%) and ammonia (55.1%). The highest heat efficiency was found for ammonia (27.4%) followed by hydrogen (25.6%). COGR resulted in similar electrical efficiencies but increased the heat efficiency by 11.9% to 105.0% for the different fuels. The model was verified with a sensitivity analysis and validated by comparison with similar studies. It is concluded that COGR is a promising method to increase the heat efficiency of marine SOFC systems.

Renewable energy sources like solar-PV and wind and the electrification of heating demand lead to more variability in the generation and demand of electricity. The need for flexibility in the electricity supply system e.g. by energy storage will therefore increase. Hydrogen has been a long-serving CO2-free energy carrier apt to store energy over a long period of time without significant losses.

The large-amplitude sloshing behavior of liquid hydrogen in a tank for heavy-duty trucks may have adverse effects on the safety and stability of driving. With successful application of liquid hydrogen in the field of new energy vehicles the coupled thermodynamic performance during liquid hydrogen large-amplitude sloshing becomes more attractive. In this paper a three-dimensional numerical model is established to simulate the thermodynamic coupling characteristics during liquid hydrogen sloshing in a horizontal tank for heavy-duty trucks. The calculation results obtained by the developed model are in good agreement with experimental data for liquid hydrogen. Based on the established 3D model the large-amplitude sloshing behavior of liquid hydrogen under extreme acceleration as well as the effects of acceleration magnitude and duration on liquid hydrogen sloshing is numerically determined. The simulation results show that under the influence of liquid hydrogen large-amplitude sloshing the convective heat transfer of fluid in the tank is greatly strengthened resulting in a decrease in the vapor temperature and an increase in the liquid temperature. In particular the vapor condensation caused by the sloshing promotes a rapid reduction of pressure in the tank. When the acceleration magnitude is 5 g with a duration of 200 ms the maximum reduction of ullage pressure is 1550 Pa and the maximum growth of the force on the right wall is 3.89 kN. Moreover the acceleration magnitude and duration have a remarkable influence on liquid hydrogen sloshing. With the increase in acceleration magnitude or duration there is a larger sloshing amplitude for the liquid hydrogen. When the duration of acceleration is 200 ms compared with the situation at the acceleration magnitude of 5 g the maximum reductions of ullage pressure decrease by 9.46% and 55.02% and the maximum growth of forces on the right wall decrease by 80.57% and 99.53% respectively at 2 g and 0.5 g. Additionally when the acceleration magnitude is 5 g in contrast with the situation at a duration of acceleration of 200 ms the maximum-ullage-pressure drops decrease by 8.17% and 21.62% and the maximum increase in forces on the right wall decrease by 71.80% and 88.63% at 100 ms and 50 ms respectively. These results can provide a reference to the safety design of horizontal liquid hydrogen tanks for heavy-duty trucks.

This research studies the current state of the Colombian industrial sector which is focused on self-generation processes. The study’s objective is to search for viable technological strategies that strengthen this particular sector’s competitiveness and sustainable development. The analysis shows that internal combustion engines represent 49% of the technologies used for self-generation. The main fuel used in the sector is natural gas with a percentage of 56%. The lack of strategies for the use of residual heat and technological inefficiencies caused a loss of 36% in the energy used in the Colombian industrial sector. Thermoelectric generators are a feasible way to recover energy from exhaust gases in engines used for self-generation. Additionally they allow a 4% reduction in fuel consumption and an improvement in the engine’s energy efficiency. The use of hydrogen as fuel allows a 30% reduction in polluting emissions such as CO2 CO HC and particulate matter. Hydrogen production processes such as water electrolysis allow the participation of Colombia’s solar energy potential leading to sustainable hydrogen production efficiency (60–80%) and a lower economic cost. In general the application of thermoelectric generators and the use of hydrogen gas allow the improvement of the Colombian industrial sector’s environmental social and economic aspects due to greater competitiveness and the reduction in emissions and operating costs.