China, People’s Republic

Decarbonizing heavy-duty trucks (HDTs) is both challenging and crucial for achieving carbon neutrality in the transport sector. Renewable hydrogen (H2) methanol (MeOH) and ammonia (NH3) offer potential solutions yet their economic viability and emission benefits remain largely unexplored. This study presents for the first time a comprehensive techno-economic analysis of using these three renewable fuels to decarbonize HDTs through detailed fuel and vehicle modeling. Six pathways are compared: hydrogen fuel cell electric trucks (FCET-H2) internal combustion engine trucks using MeOH (ICET-MeOH) and NH3 (ICET-NH3) as well as three indirect pathways that utilize these fuels for power generation to charge battery electric trucks (BETs). A novel “target powertrain cost” metric is introduced to assess the economic viability of FCET-H2 ICET-NH3 and ICET-MeOH relative to BETs. The results reveal that while BET pathways demonstrate higher well-to-wheel efficiencies significant opportunities exist for ICET-MeOH and ICET-NH3 in medium- and long-haul applications. Further more FCET-H2 achieves the lowest life cycle carbon emissions while ICET-MeOH and ICET-NH3 become more cost-effective as electricity costs decline. This study offers valuable insights and benchmarks for powertrain developers and policymakers addressing a critical gap in the comparative analysis of these three fuels for decarbonizing HDTs.

Underground hydrogen (H2) storage (UHS) and carbon dioxide (CO2) geo-storage (CGS) are prominent methods of meeting global energy needs and enabling a low-carbon global economy. The pore-scale distribution reservoir-scale storage capacity and containment security of H2 and CO2 are significantly influenced by interfacial properties including the equilibrium contact angle (θE) and solid-liquid and solid-gas interfacial tensions (γSL and γSG). However due to the technical constraints of experimentally determining these parameters they are often calculated based on advancing and receding contact angle values. There is a scarcity of θE γSL and γSG data particularly related to the hydrogen structural sealing potential of caprock which is unavailable in the literature. Young's equation and Neumann's equation of state were combined in this study to theoretically compute these three parameters (θE γSL and γSG) at reservoir conditions for the H2 and CO2 geo-storage potential. Pure mica organic-aged mica and alumina nano-aged mica substrates were investigated to explore the conditions for rock wetting phenomena and the sealing potential of caprock. The results reveal that θE increases while γSG decreases with increasing pressure organic acid concentration and alkyl chain length. However γSG decreases with increasing temperatures for H2 gas and vice versa for CO2. In addition θE and γSL decrease whereas γSG increases with increasing alumina nanofluid concentration from 0.05 to 0.25 wt%. Conversely θE and γSL increase whereas γSG decreases with increasing alumina nanofluid concentration from 0.25 to 0.75 wt%. The hydrogen wettability of mica (a proxy of caprock) was generally less than the CO2 wettability of mica at similar physio-thermal conditions. The interfacial data reported in this study are crucial for predicting caprock wettability alterations and the resulting structural sealing capacity for UHS and CGS.

The liner of a carbon fiber fully reinforced composite tank with thermoplastic liner (type IV) works in a hydrogen environment with varying temperature and pressure profiles. The ageing performance of the thermoplastic liner may affect hydrogen permeability and the consequent storage capacity degrade the mechanical properties and even increase the leakage risks of type IV tanks. In this paper both testing procedures and evaluation parameters of an ageing test in a hydrogen environment required in several standards are compared and analyzed. Hydrogen static exposure in a high-temperature condition with a constant temperature and pressure is suggested to be a reasonable way to accelerate the ageing reaction of thermoplastic materials. A total of 192 h is considered a superior ageing test duration to balance the test economy and safety. The ageing test temperature in the high-temperature condition is suggested as no lower than 85 ◦C while the upper limit of test pressure is suggested to be 1.25 NWP. In addition the hydrogen permeation coefficient and mechanical properties are recognized as important parameters in ageing performance evaluation. Considering the actual service conditions the influence of temperature/pressure cycling depressurization rate and humidity on the ageing performance of thermoplastics in hydrogen are advised to be investigated experimentally.

Magnesium-based hydrogen storage alloys have attracted significant attention as promising materials for solid-state hydrogen storage due to their high hydrogen storage capacity abundant reserves low cost and reversibility. However the widespread application of these alloys is hindered by several challenges including slow hydrogen absorption/desorption kinetics high thermodynamic stability of magnesium hydride and limited cycle life. This comprehensive review provides an in-depth overview of the recent advances in magnesium-based hydrogen storage alloys covering their fundamental properties synthesis methods modification strategies hydrogen storage performance and potential applications. The review discusses the thermodynamic and kinetic properties of magnesium-based alloys as well as the effects of alloying nanostructuring and surface modification on their hydrogen storage performance. The hydrogen absorption/desorption properties of different magnesium-based alloy systems are compared and the influence of various modification strategies on these properties is examined. The review also explores the potential applications of magnesium-based hydrogen storage alloys including mobile and stationary hydrogen storage rechargeable batteries and thermal energy storage. Finally the current challenges and future research directions in this field are discussed highlighting the need for fundamental understanding of hydrogen storage mechanisms development of novel alloy compositions optimization of modification strategies integration of magnesium-based alloys into hydrogen storage systems and collaboration between academia and industry.

With the unprecedented development of green and renewable energy sources the proportion of clean hydrogen (H2 ) applications grows rapidly. Since H2 has physicochemical properties of being highly permeable and combustible high-performance H2 sensors to detect and monitor hydrogen concentration are essential. This review discusses a variety of fiber-optic-based H2 sensor technologies since the year 1984 including: interferometer technology fiber grating technology surface plasma resonance (SPR) technology micro lens technology evanescent field technology integrated optical waveguide technology direct transmission/reflection detection technology etc. These technologies have been evolving from simply pursuing high sensitivity and low detection limits (LDL) to focusing on multiple performance parameters to match various application demands such as: high temperature resistance fast response speed fast recovery speed large concentration range low cross sensitivity excellent long-term stability etc. On the basis of palladium (Pd)-sensitive material alloy metals catalysts or nanoparticles are proposed to improve the performance of fiberoptic-based H2 sensors including gold (Au) silver (Ag) platinum (Pt) zinc oxide (ZnO) titanium oxide (TiO2 ) tungsten oxide (WO3 ) Mg70Ti30 polydimethylsiloxane (PDMS) graphene oxide (GO) etc. Various microstructure processes of the side and end of optical fiber H2 sensors are also discussed in this review.

Aiming to solve the problems of insufficient dynamic responses the large loss of energy storage life of a single power cell and the large fluctuation in DC (direct current) bus voltage in fuel cell vessels this study takes a certain type of fuel cell ferry as the research object and proposes an improved equivalent minimum hydrogen consumption energy management strategy based on fuzzy logic control. First a hybrid power system including a fuel cell a lithium–iron–phosphate battery and a supercapacitor is proposed with the simulation of the power system of the modified mother ship. Second a power system simulation model and a double-closed-loop PI (proportion integration) control model are established in MATLAB/Simulink to design the equivalent hydrogen consumption model and fuzzy logic control strategy. The simulation results show that under the premise of meeting the load requirements the control strategy designed in this paper improves the Li-ion battery’s power the Li-ion battery’s SOC (state of charge) the bus voltage stability and the equivalent hydrogen consumption significantly compared with those before optimization which improves the stability and economy of the power system and has certain practical engineering value.

To cope with climate change emerging fuels- hydrogen ammonia and methanol- have been proposed as promising energy carriers that will replace part of the liquefied natural gas (LNG) in future maritime scenarios. Energy efficiency is an important indicator for evaluating the system but the maritime supply system for emerging fuels has yet to be revealed. In this study the energy efficiency of the maritime supply chain of hydrogen ammonia methanol and natural gas is investigated considering processes including production storage loading transport and unloading. A sensitivity analysis of parameters such as ambient temperature storage time pipeline length and sailing time is also carried out. The results show that hydrogen (2.366%) has the highest daily boil-off gas (BOG) rate and wastes more energy than LNG (0.413%) with ammonia and methanol both being lower than LNG. The recycling of BOG is of great importance to the hydrogen supply chain. When produced from renewable energy sources methanol (98.02%) is the most energy efficient followed by ammonia with hydrogen being the least (89.10%). This assessment shows from an energy efficiency perspective that ammonia and methanol have the potential to replace LNG as the energy carrier of the future and that hydrogen requires efficient BOG handling systems to increase competitiveness. This study provides some inspirations for the design of global maritime supply systems for emerging fuels.

Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target. This study established an electrolytic hydrogen development mechanism considering the generation mix and operation optimization of power systems with access to hydrogen. Based on the incremental cost principle we quantified the provincial and national clean hydrogen production cost performance levels in 2030. The results indicated that this mechanism could effectively reduce the production cost of clean hydrogen in most provinces with a national average value of less than 2 USD·kg−1 at the 40-megaton hydrogen supply scale. Provincial cooperation via power transmission lines could further reduce the production cost to 1.72 USD·kg−1. However performance is affected by the potential distribution of hydrogen demand. From the supply side competitiveness of the mechanism is limited to clean hydrogen production while from the demand side it could help electrolytic hydrogen fulfil a more significant role. This study could provide a solution for the ambitious development of renewables and the hydrogen economy in China.

With the adjustment of energy structure the utilization of hydrogen energy has been widely attended. China’s carbon neutrality targets make it urgent to change traditional coal-fired power generation. The paper investigates the combustion of pulverized coal blended with hydrogen to reduce carbon emissions. In terms of calorific value the pulverized coal combustion with hydrogen at 1% 5% and 10% blending ratios is investigated. The results show that there is a significant reduction in CO2 concentration after hydrogen blending. The CO2 concentration (mole fraction) decreased from 15.6% to 13.6% for the 10% hydrogen blending condition compared to the non-hydrogen blending condition. The rapid combustion of hydrogen produces large amounts of heat in a short period which helps the ignition of pulverized coal. However as the proportion of hydrogen blending increases the production of large amounts of H2O gives an overall lower temperature. On the other hand the temperature distribution is more uniform. The concentrations of O2 and CO in the upper part of the furnace increased. The current air distribution pattern cannot satisfy the adequate combustion of the fuel after hydrogen blending.

High-pressure hydrogen tanks which are composed of an aluminum alloy liner and a carbon fiber wound layer are currently the most popular means to store hydrogen on vehicles. Nevertheless the aluminum alloy is easily affected by high-pressure hydrogen which leads to the appearance of hydrogen embrittlement (HE). Serious HE of hydrogen tank represents a huge dangers to the safety of vehicles and passengers. It is critical and timely to outline the mainstream approach and point out potential avenues for further investigation of HE. An analysis including the mechanism (including hydrogen-enhanced local plasticity model hydrogen-enhanced decohesion mechanism and hydrogen pressure theory) the detection (including slow strain rate test linearly increasing stress test and so on) and methods for the prevention of HE on aluminum alloys of hydrogen vehicles (such as coating) are systematically presented in this work. Moreover the entire experimental detection procedures for HE are expounded. Ultimately the prevention measures are discussed in detail. It is believed that further prevention measures will rely on the integration of multiple prevention methods. Successfully solving this problem is of great significance to reduce the risk of failure of hydrogen storage tanks and improve the reliability of aluminum alloys for engineering applications in various industries including automotive and aerospace.