Applications & Pathways

This review paper examines the possible pathways and possible technologies available that will help the shipping sector achieve the International Maritime Organization’s (IMO) deep decarbonization targets by 2050. There has been increased interest from important stakeholders regarding deep decarbonization evidenced by market surveys conducted by Shell and Deloitte. However deep decarbonization will require financial incentives and policies at an international and regional level given the maritime sector’s ~3% contribution to green house gas (GHG) emissions. The review paper based on research articles and grey literature discusses technoeconomic problems and/or benefits for technologies that will help the shipping sector achieve the IMO’s targets. The review presents a discussion on the recent literature regarding alternative fuels (nuclear hydrogen ammonia methanol) renewable energy sources (biofuels wind solar) the maturity of technologies (fuel cells internal combustion engines) as well as technical and operational strategies to reduce fuel consumption for new and existing ships (slow steaming cleaning and coating waste heat recovery hull and propeller design). The IMO’s 2050 targets will be achieved via radical technology shift together with the aid of social pressure financial incentives regulatory and legislative reforms at the local regional and international level.

Reducing CO₂ emissions from ships in unprofitable coastline transport using electricity and hydrogen has potential for island development to improve transport and protect biodiversity and nature. New technologies are a challenge for shipping companies and their introduction should be accompanied by a system of state aid for alternative energy sources. The energy requirements of an electric ferry for a route of up to 6 km were considered as well as the amount of hydrogen needed to generate the electricity required to charge the ferry batteries to enable a state aid scheme. For a daily ferry operation a specific fuel consumption of 60.6 g/kWh of liquid hydrogen is required in the system fuel cell with a total of 342.69 kg of hydrogen. Compared to marine diesel the use of electric ferries leads to a reduction of CO₂ emissions by up to 90% including significantly lower NOx Sox and particulate matter (PM) emissions and operating costs by up to 80%.

A rapid transition towards a CO2-neutral steel industry is required to limit climate change. Such a transition raises questions of justice as it entails positive and negative impacts unevenly distributed across societal stakeholders. To enable stakeholders to address such concerns this paper assesses the justice implications of three options that reduce emissions: CO2 capture and storage (CCS) on steel (up to 70%) bio-based steelmaking (up to 50%) and green hydrogen-based steel production (up to 100%). We select justice indicators from the energy climate labour and environmental justice literature and assess these indicators qualitatively for each of the technological routes based on literature and desk research. We find context-dependent differences in justness between the different technological routes. The impact on stakeholders varies across regions. There are justice concerns for local communities because of economic dependence on and environmental impact of the industry. Communities elsewhere are impacted through the siting of infrastructure and feedstock production. CCS and bio-based steelmaking routes can help retain industry and associated economic benefits on location while hydrogen-based steelmaking may deal better with environmental concerns. We conclude that besides techno-economic and environmental information transparency on sector-specific justice implications of transforming steel industries is essential for decision-making on technological routes

The heating sector makes up 10% of the United Kingdom’s carbon footprint and residential homes account for a majority of demand. At present central heating from a natural gas-fired boiler is the most common system in the UK but low or zero-carbon hydrogen and renewable electricity are the two primary energy replacement options to reduce the carbon footprint. An important consideration is how using either energy source would affect heating costs. This assessment projects the costs for a typical single-family UK household and climate performance in 2050 using low-GHG or GHG-neutral hydrogen renewable electricity or a combination of both. The cost of using boilers or fuel cells in 2050 with two types of hydrogen are assessed: produced via steam-methane reforming (SMR) combined with carbon capture and storage (CCS) and electrolysis using zero-carbon renewable electricity. The costs of heat pumps the most promising heating technology for the direct use of renewable electricity are also assessed in two scenarios: a heat pump only and a hybrid heat pump with an auxiliary hydrogen boiler.

You can download this document from the International Council On Clean Transportation website linked here

Increased use of renewable energy combined with intensified electrification could prove decisive for the world to meet key climate goals by 2050. This study from the International Renewable Energy Agency (IRENA) highlights immediately deployable cost-effective options for countries to fulfil climate commitments and limit the rise of global temperatures. The envisaged energy transformation would also reduce net costs and bring significant socio-economic benefits such as increased economic growth job creation and overall welfare gains.<br/>The report – the second under the Global Energy Transformation banner – expands IRENA’s comprehensive roadmap which examines technology pathways and policy implications to ensure a sustainable energy future. Ramping up electricity to over half of the global energy mix (up from one-fifth currently) in combination with renewables would reduce the use of fossil fuels responsible for most greenhouse-gas emissions.

Initial assessment of Scotland’s opportunity to produce green hydrogen from offshore wind

Summary of Key Findings

• Scotland has an abundant offshore wind resource that has the potential to be a vital component in our net zero transition. If used to produce green hydrogen offshore wind can help abate the emissions of historically challenging sectors such as heating transport and industry.
• The production of green hydrogen from offshore wind can help overcome Scotland’s grid constraints and unlock a massive clean power generation resource creating a clean fuel for Scottish industry and households and a highly valuable commodity to supply rapidly growing UK and European markets.
• The primary export markets for Scottish green hydrogen are expected to be in Northern Europe (Germany Netherlands & Belgium). Strong competition to supply these markets is expected to come from green hydrogen produced from solar energy in Southern Europe and North Africa.
• Falling wind and electrolyser costs will enable green hydrogen production to be cost-competitive in the key transport and heat sectors by 2032. Strategic investment in hydrogen transportation and storage is essential to unlocking the economic opportunity for Scotland.
• Xodus’ analysis supports a long-term outlook of LCoH falling towards £2/kg with an estimated reference cost of £2.3 /kg in 2032 for hydrogen delivered to shore.
• Scotland has extensive port and pipeline infrastructure that can be repurposed for hydrogen export to the rest of UK and to Europe. Pipelines from the ‘90s are optimal for this purpose as they are likely to retain acceptable mechanical integrity and have a metallurgy better suited to hydrogen service. A more detailed assessment of export options should be performed to provide a firm foundation for early commercial green hydrogen projects.
• There is considerable hydrogen supply chain overlap with elements of parallel sectors most notably the oil and gas offshore wind and subsea engineering sectors. Scotland already has a mature hydrocarbon supply chain which is engaged in supporting green hydrogen. However a steady pipeline of early projects supported by a clear financeable route to market will be needed to secure this supply chain capability through to widescale commercial deployment.
• There are gaps in the Scottish supply chain in the areas of design manufacture and maintenance of hydrogen production storage and transportation systems. Support including apprenticeships will be needed to develop indigenous skills and capabilities in these areas.
• The development of green hydrogen from offshore wind has the potential to create high value jobs a significant proportion which are likely to be in remote rural/coastal communities located close to offshore wind resources. These can serve as an avenue for workers to redeploy and develop skills learned from oil and gas in line with Just Transition principles.

The conversion of H2 and CO2 to liquid fuels via Power-to-Liquid (PtL) processes is gaining attention. With their higher energy densities compared to gases the use of synthetic liquid fuels is particularly interesting in hard-to-abate sectors for which decarbonisation is difficult. However PtL poses new challenges for the synthesis: away from syngas-based continuously run large-scale plants towards more flexible small-scale concepts with direct CO2-utilisation. This review provides an overview of state of the art synthesis technologies as well as current developments and pilot plants for the most prominent PtL routes for methanol DME and Fischer–Tropsch-fuels. It should serve as a benchmark for future concepts guide researchers in their process development and allow a technological evaluation of alternative reactor designs. In the case of power-to-methanol and power-to-FT-fuels several pilot plants have been realised and the first commercial scale plants are planned or already in operation. In comparison power-to-DME is much less investigated and in an earlier stage of development. For methanol the direct CO2 hydrogenation offers advantages through less by-product formation and lower heat development. However increased water formation and lower equilibrium conversion necessitate new catalysts and reactor designs. While DME synthesis offers benefits with regards to energy efficiency operational experience from laboratory tests and pilot plants is still missing. Furthermore four major process routes for power-to-DME are possible requiring additional research to determine the optimal concept. In the case of Fischer–Tropsch synthesis catalysts for direct CO2 utilisation are still in an early stage. Consequently today’s Fischer–Tropsch-based PtL requires a shift to syngas benefiting from advances in co-electrolysis and reverse water-gas shift reactor design.

The high environmental impacts of transport mean that there is an increasing interest in utilising low-carbon alternative energy carriers and powertrains within the sector. While electricity has been mooted as the energy carrier of choice for passenger vehicles as the mass and range of the vehicle increases electrification becomes more difficult. This paper reviews the shipping aviation and haulage sectors and a range of low-carbon energy carriers (electricity biofuels hydrogen and electro fuels) that can be used to decarbonise them. Energy carriers were assessed based on their energy density specific energy cost lifecycle greenhouse gas emissions and land-use. In terms of haulage current battery electric vehicles may be technically feasible however the specific energy of current battery technology reduces the payload capacity and range when compared to diesel. To alleviate these issues biomethane represents a mature technology with potential co-benefits while hydrogen is close to competitiveness but requires significant infrastructure. Energy density issues preclude the use of batteries in shipping which requires energy dense liquids or compressed gaseous fuels that allow for retrofits/current hull designs with methanol being particularly appropriate here. Future shipping may be achieved with ammonia or hydrogen but hull design will need to be changed significantly. Regulations and aircraft design mean that commercial aviation is dependant on drop-in jet fuels for the foreseeable future with power-to-liquid fuels being deemed the most suitable option due to the scales required. Fuel costs and a lack of refuelling infrastructure were identified as key barriers facing the uptake of alternatives with policy and financial incentives required to encourage the uptake of low-carbon fuels.

Hydrogen technologies have experienced cycles of excessive expectations followed by disillusion. Nonetheless a growing body of evidence suggests these technologies form an attractive option for the deep decarbonisation of global energy systems and that recent improvements in their cost and performance point towards economic viability as well. This paper is a comprehensive review of the potential role that hydrogen could play in the provision of electricity heat industry transport and energy storage in a low-carbon energy system and an assessment of the status of hydrogen in being able to fulfil that potential. The picture that emerges is one of qualified promise: hydrogen is well established in certain niches such as forklift trucks while mainstream applications are now forthcoming. Hydrogen vehicles are available commercially in several countries and 225 000 fuel cell home heating systems have been sold. This represents a step change from the situation of only five years ago. This review shows that challenges around cost and performance remain and considerable improvements are still required for hydrogen to become truly competitive. But such competitiveness in the medium-term future no longer seems an unrealistic prospect which fully justifies the growing interest and policy support for these technologies around the world.

Hydrogen fuelled vehicles can play a key role in the decarbonisation of transport and reducing emissions. To ensure the durability of fuel cells a specification has been developed (ISO 14687) setting upper limits to the amount fraction of a series of impurities. Demonstrating conformity with this standard requires demonstrating by measurement that the actual levels of the impurities are below the thresholds. Currently the industry is unable to do so for measurement standards and sensitive dedicated analytical methods are lacking. In this work we report on the development of such measurement standards and methods for four reactive components: formaldehyde formic acid hydrogen chloride and hydrogen fluoride. The primary measurement standard is based on permeation and the analytical methods on highly sensitive and selective laser-based spectroscopic techniques. Relative expanded uncertainties at the ISO 14687 threshold level in hydrogen of 4% (formaldehyde) 8% (formic acid) 5% (hydrogen chloride) and 8% (hydrogen fluoride) have been achieved.