Singapore

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.

With the development of fuel cells multi-stack fuel cell system (MFCS) for high power application has shown tremendous development potential owing to their obvious advantages including high efficiency durability reliability and pollution-free. Accordingly the state-of-the-art of MFCS is summarized and analyzed to advance its research. Firstly the MFCS applications are presented in high-power scenarios especially in transportation applications. Then to further investigate the MFCS MFCS including hydrogen and air subsystem thermal and water subsystem multi-stack architecture and prognostics and health monitoring are reviewed. It is noted that prognostics and health monitoring are investigated rarely in MFCS compared with previous research. In addition the efficiency and durability of MFCS are not only related to the application field and design principle but also the energy management strategy (EMS). The reason is that the EMS is crucial for lifespan cost and efficiency in the multi-stack fuel cell system. Finally the challenge and development potential of MFCS is proposed to provide insights and guidelines for future research.

The greenhouse effect has always been a problem troubling various country many fields have made corresponding technological improvements and regulations and the shipping industry is no exception. In the shipping field governments are actively looking for viable low-carbon/zero-carbon alternative fuels to reduce their dependence on traditional fossil fuels. This paper discusses the challenges and opportunities of replacing fuel oil with clean energies. Firstly the alternative fuels that have been proposed frequently and widely in recent years are summarized and their sources adaptive power systems and relationships among fuels are systematically summarized. Secondly when evaluating the advantages and future development trends of each energy the environmental economic and safety factors are digitally quantified. Results show that the analysis focuses on the efficiency and economics of carbon reduction. Hydrogen ammonia and nuclear energy show advantages in environmental quantification factors while LNG biofuels and alcohols show benefits in economic quantification factors considering calorific value and fuel price and LNG and alcohols received high scores in safety assessment. Finally the study predicts the evolution and development trend of ship fuels in the future and evaluates the most suitable energy for ship development in different periods.

Producing hydrogen by water electrolysis suffers from the kinetic barriers in the oxygen evolution reaction (OER) that limits the overall efficiency. With spin-dependent kinetics in OER to manipulate the spin ordering of ferromagnetic OER catalysts (e.g. by magnetization) can reduce the kinetic barrier. However most active OER catalysts are not ferromagnetic which makes the spin manipulation challenging. In this work we report a strategy with spin pinning effect to make the spins in paramagnetic oxyhydroxides more aligned for higher intrinsic OER activity. The spin pinning effect is established in oxideFM/oxyhydroxide interface which is realized by a controlled surface reconstruction of ferromagnetic oxides. Under spin pinning simple magnetization further increases the spin alignment and thus the OER activity which validates the spin effect in rate-limiting OER step. The spin polarization in OER highly relies on oxyl radicals (O∙) created by 1st dehydrogenation to reduce the barrier for subsequent O-O coupling.

Globally climate change fossil fuel depletion and greenhouse emissions are fundamental problems requiring massive effort from the international scientific community to be addressed and solved. Following the Clean Energy for all Europeans Package (CEP) guidelines the Italian Government has established challenging and tight objectives both on energy and climate matter to be targeted by 2030. Accordingly research activities on different topics are carried out in Italy looking at the installation of intermittent renewable energy systems (IRES) implementation of carbon capture and sequestration (CCS) on existing power plants and hydrogen technology and infrastructure penetration for accomplishing the end-users demands. The optimal integration of the above-mentioned technologies is one of the most effective weapons to address these objectives. The paper investigates different energy scenarios for meeting the Italian National Energy and Climate Plan (NECP) 2030 targets showing how the combined implementation of around +12 GW of IRES and +6 GW of electrolyzers compared to the national estimates simultaneously with the CCS of around 10 Mt of CO2 per year can reduce the CO2 emissions up to about 247 Mt/year. Thanks to the adoption of the well-established software platform EnergyPlan the integration of IRES plants CCS and hydrogen-based technologies have been explored and the most successful results for concurrently reducing the impact of industrial transport residential and energy sectors and mitigating the greenhouse emissions substantially relies on the diversifications. Results show both the technical and economic convenience of a 2030 energy scenario which implements properly hydrogen IRES and CCS penetration in the energy system meeting the NECP 2030 targets and maintaining both the over-generation of the power plants below 5 TWh and the initial capital expenditure to be sustained for this scenario to occur below +80% compared to the 2019 energy scenario.

Hydrogen is considered to the ultimate solution to achieve carbon emission reduction due to its wide sources and high calorific value as well as non-polluting renewable and storable advantages. This paper starts from the coastal areas uses offshore wind power hydrogen production as the hydrogen source and focuses on the combination of hydrogen supply chain network design and hydrogen expressway hydrogen refueling station layout optimization. It proposes a comprehensive mathematical model of hydrogen supply chain network based on cost analysis which determined the optimal size and location of hydrogen refueling stations on hydrogen expressways in coastal areas. Under the multi-scenario and multi-case optimization results the location of the hydrogen refueling station can effectively cover the road sections of each case and the unit hydrogen cost of the hydrogen supply chain network is between 11.8 and 15.0 USD/kgH2 . Meanwhile it was found that the transportation distance and the number of hydrogen sources play a decisive role on the cost of hydrogen in the supply chain network and the location of hydrogen sources have a decisive influence on the location of hydrogen refueling stations. In addition carbon emission reduction results of hydrogen supply chain network show that the carbon emission reduction per unit hydrogen production is 15.51 kgCO2/kgH2 at the production side. The CO2 emission can be reduced by 68.3 kgCO2/km and 6.35 kgCO2/kgH2 per unit mileage and per unit hydrogen demand at the application side respectively. The layout planning utilization of hydrogen energy expressway has a positive impact on energy saving and emission reduction.

Liquid hydrogen (LH2) aircraft have the potential to achieve carbon neutrality. However if the hydrogen is produced using electricity grids that utilise fossil fuel they have a non-zero carbon dioxide (CO2) emission associated with their well-to-wing pathway. To assess the potential of LH2 in aviation decarbonisation an energy systems comparison of large commercial LH2 liquified natural gas (LNG) conventional Jet-A and LH2 dual-fuel aircraft is presented. The performance of each aircraft is compared towards 2050 over which three system changes occur: (1) LH2 aircraft technology develops; (2) both world average and region-specific grid electricity which is used to produce the hydrogen decarbonises; and (3) the International Air Transportation Association (IATA) emissions targets which are used to restrict the passenger-range performance of each aircraft tighten. In 2050 the emissions of all aircraft are thus constrained to 0.063 kg-CO2/p-km relative to 0.110 kg-CO2/p-km for the unconstrained Jet A fuelled Boeing 787-8. It is estimated that in this year an LH2 aircraft powered by fuel cells and sourcing world average electricity can travel 6000 km 20% further than the conventional Jet A aircraft that is also constrained to meet the IATA targets but not as far as the LNG aircraft. At its maximum range the LH2 aircraft carries 84% of the Jet A passenger demand. Analysis using region-specific hydrogen indicates that LH2 aircraft can travel further than LNG aircraft in North America only accounting for 17% of the global demand. 1.59 times the current aviation energy consumption is required if all conventional aircraft are replaced with LH2 designs. Under stricter emissions constraints than those outlined by the IATA LH2 outperforms LNG in Europe and the Americas accounting for 41% of the global demand. Also in these regions the range energy consumption and passenger capacity of LH2 aircraft can be improved upon by combining the advantages of LH2 with LNG in dual-fuel aircraft concepts. The use of LH2 is therefore advantageous within several prominent niches of a future decarbonising aviation system.

A key building block of the European Green Deal is the development of a hydrogen commodity market which requires a suitable hydrogen market design and the timely introduction of related policy measures. Using exploratory interviews with five expert groups we contribute to this novel research field by outlining the core market design criteria and proposing suitable regulations for the future European hydrogen market. We identify detailed recommendations along three core market design focus areas: Market development policy measures infrastructure regulations as well as hydrogen and certificate trading. Our findings provide an across-industry view of current policy-related key challenges in the hydrogen commodity market development and mitigation approaches. We therefore support policymakers within the EU in the ongoing detailing of their regulatory hydrogen and green energy packages. Further we promote hydrogen market development by assisting current and future industry players in finding a common understanding of the future hydrogen market design.

The global resurgence of hydrogen as a clean energy source particularly green hydrogen derived from renewable energy is pivotal for achieving a carbon-neutral future. However scalability poses a significant challenge. This research proposes innovative business models leveraging the low-emission property of green hydrogen to reduce its financial costs thereby fostering its widespread adoption. Key components of the business workflow are elaborated mathematical formulations of market parameters are derived and case studies are presented to demonstrate the feasibility and efficiency of these models. Results demonstrate that the substantial costs associated with the current hydrogen industry can be effectively subsidized via the implementation of proposed business models. When the carbon emission price falls within the range of approximately 86–105 USD/ton free access to hydrogen becomes a viable option for end-users. This highlights the significance and promising potential of the proposed business models within the green hydrogen credit framework.

Singapore has committed to achieving net zero emissions by 2050 which requires the pursuit of multiple decarbonization pathways. CO2 utilization methods such as fuel production may provide a fast interim solution for carbon abatement. This paper evaluates the feasibility of green hydrogen-based synthetic fuel (synfuel) production as a method for utilizing captured CO2. We consider several scenarios: a baseline scenario with no changes local production of synfuel with hydrogen imports and overseas production of synfuel with CO2 exports. This paper aims to determine a CO2 price for synfuel production evaluate the economic viability of local versus overseas production and investigate the effect of different cost parameters on economic viability. Using the current literature we estimate the associated production and transport costs under each scenario. We introduce a CO2 utilization price (CUP) that estimates the price of utilizing captured CO2 to produce synfuel and an adjusted CO2 utilization price (CCUP) that takes into account the avoided emissions from crude oil-based fuel production. We find that overseas production is more economically viable compared to local production with the best case CCUP bounds giving a range of 142–148 $/tCO2 in 2050 if CO2 transport and fuel shipping costs are low. This is primarily due to the high cost of hydrogen feedstock especially the transport cost which can offset the combined costs of CO2 transport and fuel shipping. In general we find that any increase in the hydrogen feedstock cost can significantly affect the CCUP for local production. Sensitivity analysis reveals that hydrogen transport cost has a significant impact on the viability of local production and if this cost is reduced significantly local production can be cheaper than overseas production. The same is true if the economies of scale for local production is significantly better than overseas production. A significantly lower carbon capture cost can also the reduce the CCUP significantly.