Malaysia

Decarbonization of the shipping sector is inevitable and can be made by transitioning into low‐ or zero‐carbon marine fuels. This paper reviews 22 potential pathways including conventional Heavy Fuel Oil (HFO) marine fuel as a reference case “blue” alternative fuel produced from natural gas and “green” fuels produced from biomass and solar energy. Carbon capture technology (CCS) is installed for fossil fuels (HFO and liquefied natural gas (LNG)). The pathways are compared in terms of quantifiable parameters including (i) fuel mass (ii) fuel volume (iii) life cycle (Well‐To‐ Wake—WTW) energy intensity (iv) WTW cost (v) WTW greenhouse gas (GHG) emission and (vi) non‐GHG emissions estimated from the literature and ASPEN HYSYS modelling. From an energy perspective renewable electricity with battery technology is the most efficient route albeit still impractical for long‐distance shipping due to the low energy density of today’s batteries. The next best is fossil fuels with CCS (assuming 90% removal efficiency) which also happens to be the lowest cost solution although the long‐term storage and utilization of CO2 are still unresolved. Biofuels offer a good compromise in terms of cost availability and technology readiness level (TRL); however the non‐GHG emissions are not eliminated. Hydrogen and ammonia are among the worst in terms of overall energy and cost needed and may also need NOx clean‐up measures. Methanol from LNG needs CCS for decarbonization while methanol from biomass does not and also seems to be a good candidate in terms of energy financial cost and TRL. The present analysis consistently compares the various options and is useful for stakeholders involved in shipping decarbonization.

An accident modelling approach is used to assess the safety of a hydrogen station as part of a ground transportation network. The method incorporates prevention barriers associated to human factors management and organizational failures in a risk assessment framework. Failure probabilities of these barriers and end-states events are predicted using Fault Tree Analysis and Event Tree Analysis respectively. Results from the case study considered revealed the capability of the proposed method in estimating the likelihood of various outcomes as well as predicting the future probability. In addition the scheme offers opportunity to provide dynamic adjustment by updating the failure probability with actual plant data. Results from the analysis can be used to plan maintenance and management of change as required by the plant condition.

Hydrogen combustion in a noble gas atmosphere increases the combustion chamber temperature and the high specific heat ratio of the gas increases the thermal efficiency. In this study nitrogen was replaced by argon as the intake air along with pure oxygen to supply the engine. The objectives of this study are to determine the effects of different engine parameters on combustion and to analyse the emissions from hydrogen combustion in an argon-oxygen atmosphere. This research was conducted through simulations using CONVERGE 2.2.0 software and the YANMAR engine NF19SK model was used to determine the basic parameters. Changing the injector location affects the pressure and temperature in the combustion chamber. With increasing compression ratio the pressure increases more rapidly than the temperature. However combustion at high compression ratios decreases the maximum heat release rate and increases the combustion duration. Hydrogen combustion at ambient temperatures below 1200 K follows the Arrhenius equation.

Due to energy and environmental issues hydrogen has become a more attractive clean fuel. Furthermore there is high interest in producing hydrogen from biomass with a view to sustainability. The thermochemical process for hydrogen production i.e. gasification is the focus of this work. This paper discusses the mathematical modeling of hydrogen production process via biomass steam gasification with calcium oxide as sorbent in a gasifier. A modelling framework consisting of kinetics models for char gasification methanation Boudouard methane reforming water gas shift and carbonation reactions to represent the gasification and CO2 adsorption in the gasifier is developed and implemented in MATLAB. The scope of the work includes an investigation of the influence of the temperature steam/biomass ratio and sorbent/biomass ratio on the amount of hydrogen produced product gas compositions and carbon conversion. The importance of different reactions involved in the process is also discussed. It is observed that hydrogen production and carbon conversion increase with increasing temperature and steam/biomass ratio. The model predicts a maximum hydrogen mole fraction in the product gas of 0.81 occurring at 950 K steam/biomass ratio of 3.0 and sorbent/biomass ratio of 1.0. In addition at sorbent/biomass ratio of 1.52 purity of H2 can be increased to 0.98 mole fraction with all CO2 present in the system adsorbed.

In the present study hydrogen utilization as diesel engine fuel at low load operation was investigated. Hydrogen cannot be used directly in a diesel engine due to its auto ignition temperature higher than that of diesel fuel. One alternative method is to use hydrogen in enrichment or induction. To investigate the combustion characteristics of this dual fuel engine a single cylinder diesel research engine was converted to utilize hydrogen as fuel. Hydrogen was introduced to the intake manifold using a mixer before entering the combustion chamber. The engine was run at a constant speed of 2000 rpm and 10 Nm load. Hydrogen was introduced at the flow rate of 21.4 36.2 and 49.6 liter/minute. Specific energy consumption indicated efficiency and cylinder pressure were investigated. At this low load the hydrogen enrichment reduced the cylinder peak pressure and the engine efficiency. The reaction progress variable and combustion rate of reaction were slower as shown by the CFD calculation.

The transition of Malaysia from fossil fuels to renewable energy sources provides significant challenges and opportunities for various energy sectors. Incorporation of H₂ in the primary energy mix requires a deal of complexity in its relation to production transportation and end-use. The Sarawak State Government in Malaysia implemented a hydrogen energy roadmap for the year 2005–2030 on the state-level but despite the great enthusiasm and full support given by the government the development of hydrogen technology is still far from its goals. This is due to several factors that hinder its progress including (1) inability of hydrogen to be integrated with current primary energy infrastructure (2) limited technology resources to produce sustainable hydrogen and (3) lack of technical expertise in the field of hydrogen. In this paper a potential national roadmap and milestones are presented based on the power-to-gas (P2G) approach combined with its implications on the national natural gas (NG) pipeline network. Besides that the long-term and short-term strategies and implementation mechanisms are discussed in detail. Furthermore complete research schemes are formulated to be inline with the presented vision to further enhance technology development and implementation.

A solid-state storage system is the most practical option for hydrogen because it is more convenient and safer. Metal hydrides especially MgH₂ are the most promising materials that offer high gravimetric capacity and good reversibility. However the practical application of MgH₂ is restricted by slow sorption kinetics and high stability of thermodynamic properties. Hydrogen storage performance of MgH₂ was enhanced by introducing the Mg–Na–Al system that destabilises MgH₂ with NaAlH₄. The Mg–Na–Al system has superior performance compared to that of unary MgH₂ and NaAlH₄. To boost the performance of the Mg–Na–Al system the ball milling method and the addition of a catalyst were introduced. The Mg–Na–Al system resulted in a low onset decomposition temperature superior cyclability and enhanced kinetics performances. The Al12Mg17 and NaMgH₃ that formed in situ during the dehydrogenation process modify the reaction pathway of the Mg–Na–Al system and alter the thermodynamic properties. In this paper the overview of the recent progress in hydrogen storage of the Mg–Na–Al system is detailed. The remaining challenges and future development of Mg–Na–Al system are also discussed. This paper is the first review report on hydrogen storage properties of the Mg–Na–Al system.

This study presents an overview of the economic analysis and environmental impact of natural gas conversion technologies. Published articles related to economic analysis and environmental impact of natural gas conversion technologies were reviewed and discussed. The economic analysis revealed that the capital and the operating expenditure of each of the conversion process is strongly dependent on the sophistication of the technical designs. The emerging technologies are yet to be economically viable compared to the well-established steam reforming process. However appropriate design modifications could significantly reduce the operating expenditure and enhance the economic feasibility of the process. The environmental analysis revealed that emerging technologies such as carbon dioxide (CO2) reforming and the thermal decomposition of natural gas offer advantages of lower CO2 emissions and total environmental impact compared to the well-established steam reforming process. Appropriate design modifications such as steam reforming with carbon capture storage and utilization the use of an optimized catalyst in thermal decomposition and the use of solar concentrators for heating instead of fossil fuel were found to significantly reduced the CO2 emissions of the processes. There was a dearth of literature on the economic analysis and environmental impact of photocatalytic and biochemical conversion processes which calls for increased research attention that could facilitate a comparative analysis with the thermochemical processes.

The concerns regarding the consumption of traditional fuels such as oil and coal have driven the proposals for several cleaner alternatives in recent years. Hydrogen energy is one of the most attractive alternatives for the currently used fossil fuels with several superiorities such as zero-emission and high energy content. Hydrogen has numerous advantages compared to conventional fuels and as such has been employed in gas turbines (GTs) in recent years. The main benefit of using hydrogen in power generation with the GT is the considerably lower emission of greenhouse gases. The performance of the GTs using hydrogen as a fuel is influenced by several factors including the performance of the components the operating condition ambient condition etc. These factors have been investigated by several scholars and scientists in this field. In this article studies on hydrogen-fired GTs are reviewed and their results are discussed. Furthermore some recommendations are proposed for the upcoming works in this field.

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.