Malaysia

Hydrogen gas has tremendous potential as an environmentally acceptable energy carrier for vehicles. A cutting edge technology called a microbial electrolysis cell (MEC) can achieve sustainable and clean hydrogen production from a wide range of renewable biomass and wastewaters. Enhancing the hydrogen production rate and lowering the energy input are the main challenges of MEC technology. MEC reactor design is one of the crucial factors which directly influence on hydrogen and current production rate in MECs. The rector design is also a key factor to upscaling. Traditional MEC designs incorporated membranes but it was recently shown that membrane-free designs can lead to both high hydrogen recoveries and production rates. Since then multiple studies have developed reactors that operate without membranes. This review provides a brief overview of recent advances in research on scalable MEC reactor design and configurations.

The world has relied on fossil fuel energy for a long time producing many adverse effects. Long-term fossil fuel dependency has increased carbon emissions and accelerated climate change. In addition fossil fuels are also depleting and will soon be very costly. Moreover the expensive national electricity grid has yet to reach rural areas and will be cut off in inundation areas. As such alternative and carbon-free hydrogen fuel cell energy is highly recommended as it solves these problems. The reviews find that (i) compared to renewable energy such as solar biomass and hydropower a fuel cell does not require expensive transmission through an energy grid and is carbon-free and hence it is a faster agent to decelerate climate change; (ii) fuel cell technologies have reached an optimum level due to the high-efficiency production of energy and they are environmentally friendly; (iii) the absence of a policy on hydrogen fuel cells will hinder investment from private companies as they are not adequately regulated. It is thus recommended that countries embarking on hydrogen fuel cell development have a specific policy in place to allow the government to fund and regulate hydrogen fuel cells in the energy generation mix. This is essential as it provides the basis for alternative energy governance development and management of a country.

Conventional fuels for vehicular applications generate hazardous pollutants which have an adverse effect on the environment. Therefore there is a high demand to shift towards environment-friendly vehicles for the present mobility sector. This paper highlights sustainable mobility and specifically sustainable transportation as a solution to reduce GHG emissions. Thus hydrogen fuel-based vehicular technologies have started blooming and have gained significance following the zero-emission policy focusing on various types of sustainable motilities and their limitations. Serving an incredible deliverance of energy by hydrogen fuel combustion engines hydrogen can revolution various transportation sectors. In this study the aspects of hydrogen as a fuel for sustainable mobility sectors have been investigated. In order to reduce the GHG (Green House Gas) emission from fossil fuel vehicles researchers have paid their focus for research and development on hydrogen fuel vehicles and proton exchange fuel cells. Also its development and progress in all mobility sectors in various countries have been scrutinized to measure the feasibility of sustainable mobility as a future. This paper is an inclusive review of hydrogen-based mobility in various sectors of transportation in particular fuel cell cars that provides information on various technologies adapted with time to add more towards perfection. When compared to electric vehicles with a 200-mile range fuel cell cars have a lower driving cost in all of the 2035 and 2050 scenarios. To stimulate the use of hydrogen as a passenger automobile fuel the cost of a hydrogen fuel cell vehicle (FCV) must be brought down to at least the same level as an electric vehicle. Compared to gasoline cars fuel cell vehicles use 43% less energy and generate 40% less CO2.

Fuel transition can decarbonize shipping and help meet IMO 2050 goals. In this paper HFO with CCS LNG with CCS bio-methanol biodiesel hydrogen ammonia and electricity were studied using empirical ship design models from a fleet-level perspective and at the Tank-ToWake level to assist operators technology developers and policy makers. The cargo attainment rate CAR (i.e. cargo that must be displaced due to the low-C propulsion system) the ES (i.e. TTW energy needed per ton*n.m.) the CS (economic cost per ton*n.m.) and the carbon intensity index CII (gCO2 per ton*n.m.) were calculated so that the potential of the various alternatives can be compared quantitatively as a function of different criteria. The sensitivity of CAR towards ship type fuel type cargo type and voyage distance were investigated. All ship types had similar CAR estimates which implies that considerations concerning fuel transition apply equally to all ships (cargo containership tankers). Cargo type was the most sensitive factor that made a ship either weight or volume critical indirectly impacting on the CAR of different fuels; for example a hydrogen ship is weight-critical and has 2.3% higher CAR than the reference HFO ship at 20000 nm. Voyage distance and fuel type could result in up to 48.51% and 11.75% of CAR reduction. In addition to CAR the ES CS and CII for a typical mission were calculated and it was found that HFO and LNG with CCS gave about 20% higher ES and CS than HFO and biodiesel had twice the cost while ammonia methanol and hydrogen had 3–4 times the CS of HFO and electricity about 20 times suggesting that decarbonisation of the world’s fleet will come at a large cost. As an example of including all factors in an effort to create a normalized scoring system an equal weight was allocated to each index (CAR ES CS and CII). Biodiesel achieved the highest score (80%) and was identified as the alternative with the highest potential for a deep-seagoing containership followed by ammonia hydrogen bio-methanol and CCS. Electricity has the lowest normalized score of 33%. A total of 100% CAR is achievable by all alternative fuels but with compromises in voyage distance or with refuelling. For example a battery containership carrying an equal amount of cargo as an HFO-fuelled containership can only complete 13% of the voyage distance or needs refuelling seven times to complete 10000 n.m. The results can guide decarbonization strategies at the fleet level and can help optimise emissions as a function of specific missions.

This paper discusses the optimal control of pressure using the zero-gradient control (ZGC) approach. It is applied for the first time in the study to control the optimal pressure of hydrogen natural gas mixture in an inclined pipeline. The solution to the flow problem is first validated with existing results using the Taylor series approximation regression analysis and the Runge-Kutta method combined. The optimal pressure is then determined using ZGC where the optimal set points are calculated without having to solve the non-linear system of equations associated with the standard optimization problem. It is shown that the mass ratio is the more effective parameter compared to the initial pressure in controlling the maximum variation of pressure in a gas pipeline.

Biomass can be a sustainable choice for bioenergy production worldwide. Biohydrogen production using fermentative conversion of biomass has gained great interest during the last decade. Besides being an efficient transportation fuel biohydrogen can also be also be a low-carbon source of heat and electricity. Microbes assisted conversion (bioconversion) can be take place either in presence or absence of light. This is called photofermentation or dark-fermentation respectively. This review provides an overview of approaches of fermentative hydrogen production. This includes: dark photo and integrated fermentative modes of hydrogen production; the molecular basis behind its production and diverse range of its applicability industrially. Mechanistic understanding of the metabolic pathways involved in biomass-based fermentative hydrogen production are also reviewed.

The ignition of hydrogen in compression ignition (CI) engines by adding noble gas as a working gas can yield excellent thermal efficiency due to its high specific heat ratio. This paper emphasizes the potential of helium–oxygen atmosphere for hydrogen combustion in CI engines and provides data on the engine configuration. A simulation was conducted using Converge CFD software based on the Yanmar NF19SK engine parameters. Helium–oxygen atmosphere compression show promising hydrogen autoignition results with the in-cylinder temperature was significantly higher than that of air during the compression stroke. In a compression ignition engine with a low compression ratio (CR) and intake temperature helium–oxygen atmosphere is recognized as the best working gas for hydrogen combustion. The ambient intake temperature was sufficient for hydrogen ignition in low CR with minimal heat flux effect. The best intake temperature for optimum engine efficiency in a low CR engine is 340 K and the engine compression ratio for optimum engine efficiency at ambient intake temperature is CR12 with an acceptable cylinder wall heat flux value. The helium–oxygen atmosphere as a working gas for hydrogen combustion in CI engines should be consider based on the parameter provided for clean energy transition with higher thermal efficiency.

An investigation was conducted to determine the effects of operating parameters for various electrode types on hydrogen gas production through electrolysis as well as to evaluate the efficiency of the polymer electrolyte membrane (PEM) electrolyzer. Deionized (DI) water was fed to a single-cell PEM electrolyzer with an active area of 36 cm2 . Parameters such as power supply (50–500 mA/cm2 ) feed water flow rate (0.5–5 mL/min) water temperature (25−80 ◦C) and type of anode electrocatalyst (0.5 mg/cm2 PtC [60%] 1.5 mg/cm2 IrRuOx with 1.5 mg/cm2 PtB 3.0 mg/cm2 IrRuOx and 3.0 mg/cm2 PtB) were varied. The effects of these parameter changes were then analyzed in terms of the polarization curve hydrogen flowrate power consumption voltaic efficiency and energy efficiency. The best electrolysis performance was observed at a DI water feed flowrate of 2 mL/min and a cell temperature of 70 ◦C using a membrane electrode assembly that has a 3.0 mg/cm2 IrRuOx catalyst at the anode side. This improved performance of the PEM electrolyzer is due to the reduction in activation as well as ohmic losses. Furthermore the energy consumption was optimal when the current density was about 200 mA/cm2 with voltaic and energy efficiencies of 85% and 67.5% respectively. This result indicates low electrical energy consumption which can lower the operating cost and increase the performance of PEM electrolyzers. Therefore the optimal operating parameters are crucial to ensure the ideal performance and durability of the PEM electrolyzer as well as lower its operating costs.

The pressure to move to sustainable energy sources is obvious in today's fast changing energy environment. In this context green hydrogen appears as a beacon of hope with the potential to reinvent the paradigms of energy consumption particularly in the transportation and aviation sectors. Hydrogen has long been intriguing owing to its unique characteristics. It is not only an energy transporter; it has the power to alter the game. Its growing significance is due to its capacity to decarbonize energy generation. Traditional hydrogen generation techniques have contributed considerably to world CO2 emissions accounting for over 2% of total emissions. This environmental problem is successfully addressed by the development of green hydrogen which is created from renewable energy sources. The International Energy Agency (IEA) predicts a 25 to 30 percent increase in global energy consumption by 2040 which is a very grim scenario. If continue to rely on coal and oil this growing demand will result in greater CO2 emissions exacerbating climate change's consequences. In this situation green hydrogen is not only an option but a need. Because green hydrogen has properties with conventional fuels it can be simply integrated into current infrastructure. This harmonic integration ensures that the shift to hydrogen-based solutions in these sectors would not demand a complete redesign of the present systems assuring cost-effectiveness and practicality. However like with any energy source green hydrogen has obstacles. Its combustibility and probable explosiveness have been cited as causes for concern. However developments in safety measures have successfully mitigated these dangers ensuring that hydrogen may be used safely and efficiently across various applications. A further difficulty is its energy density particularly in comparison to conventional fuels. While its energy-to-weight ratio may be good its bulk poses challenges particularly in the aviation industry where space is at a premium. Beyond its direct use as a fuel green hydrogen has potential in auxiliary capacities. It may be used as a dependable backup energy source during power outages as well as in a variety of different sectors and uses ranging from manufacturing to residential. Green hydrogen's adaptability demonstrates its potential to infiltrate all sectors of our economy. Storage is an important enabler for broad hydrogen use. Effective hydrogen storage technologies guarantee not only its availability but also its viability as a source of energy. Current research and advancements in this field are encouraging which strengthens the argument for green hydrogen. At conclusion green hydrogen is in the vanguard of sustainable energy solutions particularly for the transportation and aviation industries. In our collaborative quest of a sustainable future its unique features and environmental advantages make it a vital asset. As we explore further into the complexities of green hydrogen in this publication we want to shed light on its potential obstacles and future route.

Demand for hydrogen has grown and continues to rise as a versatile energy carrier. Hydrogen can be produced from renewable and non-renewable energy sources. A wide range of technologies to produce hydrogen in an environmentally friendly way have been developed. As the life cycle assessment (LCA) approach has become popular recently including in the hydrogen energy system this paper comprehensively reviews the LCA of hydrogen production technology. A subdivision based on the trends in the LCA studies hydrogen production technology goal and scope definition system boundary and environmental performance of hydrogen production is discussed in this review. Thermochemical hydrogen production is the most studied technology in LCA. However utilizing natural resources especially wind power in the electrolysis process stands out as an environmentally preferable solution when compared to alternative production processes. It is crucial to rethink reactors and other production-related equipment to improve environmental performance and increase hydrogen production efficiency. Since most of the previous LCA studies were conducted in developed countries and only a few were from developing countries a way forward for LCA application on hydrogen in developing countries was also highlighted and discussed. This review provides a comprehensive insight for further research on hydrogen production technology from an LCA perspective.