Search Results (153)

Decarbonisation of the transport sector, whilst reducing pollutant emissions, will likely involve the utilisation of multiple strategies, including hybridisation and the use of alternative fuels such as advanced biofuels as mandated by the EU. Alcoholysis of lignocellulosic feedstocks, using n-butanol as the solvent, can produce such potential advanced biofuel blends. Butyl blends, consisting of n-butyl levulinate (nBL), di-n-butyl ether, and n-butanol, were selected for this study. Three butyl blends with diesel, two at 10 vol% biofuel and one at 25 vol% biofuel, were tested in a Euro 6b-compliant diesel hybrid vehicle to determine the influence of the blends on regulated emissions and fuel economy. Real Driving Emissions (RDE) were measured for three cold start tests with each fuel using a Portable Emissions Measurement System (PEMS) for carbon monoxide (CO), particle number (PN), and nitrogen oxides (NO_X = NO + NO₂). When using the butyl blends, there was no noticeable change in vehicle drivability and only a small fuel economy penalty of up to 5% with the biofuel blends relative to diesel. CO, NO_X, and PN emissions were below or within one standard deviation of the Euro 6 not-to-exceed limits for all fuels tested. The CO and PN emissions reduced relative to diesel by up to 72% and 57%, respectively. NO_X emissions increased relative to diesel by up to 25% and increased with both biofuel fraction and the amount of nBL in that fraction. The CO emitted during the cold start period was reduced by up to 52% for the 10 vol% blends but increased by 25% when using the 25 vol% blend. NO_X and PN cold start emissions reduced relative to diesel for all three biofuel blends by up to 29% and 88%, respectively. It is envisaged that the butyl blends could reduce net carbon emissions without compromising or even improving air pollutant emissions, although optimisation of the after-treatment systems may be necessary to ensure emissions limits are met. Full article

Sustainable transport innovation often faces funding gaps, as traditional public and private sources rarely support early-stage or high-risk initiatives. Crowdfunding, enabled by digital transformation, is emerging as a complementary financing mechanism for this sector. This study presents a literature review combined with bibliometric mapping to examine the evolving research landscape on crowdfunding in transport. Three research questions guide the analysis: RQ1—What are the dominant research areas at the intersection of crowdfunding and transport? RQ2—What types of transport projects are financed via crowdfunding? RQ3—What research gaps and future directions emerge for transport innovation financing? Findings reveal three core research areas: (1) Sustainability and finance, (2) Fintech and blockchain, and (3) Management and consumer behavior. We propose a typology of crowdfunded transport projects comprising five categories: (1) Large-scale transport infrastructure, (2) Sustainable local mobility, (3) Innovative start-ups, (4) New business models, and (5) Advanced systems and technologies. This demonstrates crowdfunding’s versatility beyond traditional infrastructure, supporting high-risk innovations critical for decarbonization and technological transformation. The study highlights domain-specific challenges—such as integrating PPP models with digital finance and ensuring investor protection—and emphasizes crowdfunding’s role as an enabler of low-carbon transition aligned with global climate strategies (EU Green Deal, SDGs). Despite its potential, investor safety remains a major concern. Policy implications include sandbox regulation, standardized risk assessment, and operationalizing PPP–crowdfunding hybrids to unlock large-scale and innovative transport projects. Full article

Greenhouse gas (GHG) emissions from maritime transport account for nearly 3% of global totals, making the decarbonisation of this sector a critical priority. In response, the International Maritime Organization (IMO) adopted the GHG Strategy, targeting the full decarbonisation of international shipping by 2050, with interim milestones in 2030 and 2040. This study evaluates the greenhouse gas fuel intensity of three representative vessel types, an oil tanker, a container ship, and a bulk carrier, using one-year operational fuel consumption data in line with the Regulations of the IMO Net-Zero Framework. Both conventional fuels, including conventional marine fuels, and alternative options, encompassing liquefied natural gas (LNG), e-hydrogen, e-ammonia, e-methanol, and biodiesel, are assessed for compliance during 2028–2035. The findings reveal that conventional fuels are unable to meet future targets, resulting in significant compliance deficits and balancing costs of remedial units. LNG provides short-term benefits but is limited by methane slip. In contrast, e-hydrogen and e-ammonia enable long-term compliance and generate surplus units. E-methanol shows a partial potential, while biodiesel delivers only modest improvements. The results underscore the need for a transition toward near-zero-well-to-wake-emission fuels. This study contributes by combining life cycle assessments with regulatory compliance analysis, offering insights for policymakers and industry stakeholders. Full article

This paper reviews the role of high-speed rail (HSR) and other fast rail technologies in decarbonising inter-urban transport. It first outlines the global deployment of HSR, with particular emphasis on Europe and China, and situates these networks within the wider geography of fast rail systems. The paper then compares HSR with competing modes such as air transport and passenger cars along key dimensions including door-to-door travel time, energy use and emissions. Building on a qualitative synthesis of the international literature, it discusses the environmental, economic and social impacts of HSR, highlighting conditions under which HSR can deliver substantial modal shift and life-cycle greenhouse gas savings, as well as situations where benefits are more limited or unevenly distributed. Finally, the review briefly considers emerging fast rail concepts such as Maglev and Hyperloop and argues that they should currently be treated as complementary, long-term options rather than immediate substitutes for conventional HSR. Full article

Urbanisation and the increasing concentration of populations in cities present significant challenges for achieving sustainable mobility and advancing the energy transition. Private vehicles, particularly those powered by internal combustion engines, remain the primary contributors to urban air pollution and greenhouse gas emissions. This situation has prompted the European Union to accelerate transport decarbonisation through comprehensive policy frameworks, notably the “Fit for 55” package, which aims to reduce net greenhouse gas emissions by 55% by 2030. These measures underscore the urgency of shifting towards low-emission transport modes. In this context, electric vehicles (EVs) play a key role in supporting Sustainable Development Goal 7 by promoting cleaner and more efficient transport solutions, and Sustainable Development Goal 11, aimed at creating more sustainable and liveable cities. Despite growing policy attention, the adoption of EVs remains constrained by users’ concerns regarding purchase costs, driving range, and the availability of charging infrastructure, as shown by the findings of this study. In this context, this study explores the determinants of EV adoption in Italy by employing a combined methodological approach that integrates a stated preference (SP) survey with discrete choice modelling. The analysis aims to quantify the influence of economic, technical, and infrastructural factors on users’ willingness to switch to EVs, providing insights for policymakers and industry stakeholders to design effective strategies for accelerating the transition toward the sustainable mobility. Full article

Green hydrogen is a potential enabler of deep decarbonisation for industrial process heat. We assess its role in Aotearoa New Zealand using a bottom-up, least-cost energy-system model based on the integrated MARKAL-EFOM system (TIMES), which includes hydrogen production electrolysis, storage, and delivery of end-use technologies for process heat, as well as alternative low-carbon options. Drawing on detailed data on industrial energy use by sector and temperature band, we simulate pathways to 2050 under varying assumptions for electrolyser and fuel prices, technology efficiencies, electricity decarbonisation and carbon prices. In most scenarios, the least-cost pathway involves widespread electrification of low- and medium-temperature heat, with green hydrogen playing a targeted role where high-temperature requirements and process constraints limit direct electrification. Sensitivity analysis reveals that hydrogen uptake increases under higher carbon prices, lower electrolyser capital expenditure, and when grid connection or peak capacity constraints are binding. These results suggest that policy should prioritise rapid industrial electrification while focusing hydrogen support on hard-to-electrify, high-temperature processes, such as primary metals and mineral products, alongside enabling infrastructure and standards for hydrogen production, transport, and storage. Full article

The global decarbonisation strategy has accelerated the shift toward renewable energy and electric transport, demanding advanced electrochemical energy storage systems. Conventional anodes such as graphite and silicon composites face challenges in conductivity, stability and cycling performance. MXenes, a class of two-dimensional (2D) materials, offer promising alternatives owing to their metallic conductivity, tunable surface chemistry and high theoretical capacity. Here, we synthesise and characterise Mo₂TiC₂T_x and V₂CT_x (T = O, OH, F and/or Cl) MXenes for lithium-ion battery anodes and supercapacitors. Unlike Ti₃C₂T_x, which stores charge via intercalation and surface redox reactions, Mo₂TiC₂T_x and V₂CT_x exhibit conversion-type mechanisms. We also identify novel V₂C–VO_x heterostructures, achieving a specific capacitance of 532.4 F g⁻¹ at 2 mV s⁻¹ and an initial capacity of 493.3 mAh g⁻¹ at 50 mA g⁻¹ in lithium half-cells, with a low decay rate of 0.071% per cycle over 200 cycles. Pristine Mo₂TiC₂T_x shows 391.7 mAh g⁻¹ at 50 mA g⁻¹, decaying by 0.109% per cycle. These results experimentally validate theoretical predictions, revealing how MXene structure and transition metal chemistry govern electrochemical behaviour, thus guiding electrode design for next-generation batteries and supercapacitors. Full article

Biofuels are critical drop-in replacement energy sources to support the decarbonisation of hard-to-abate sectors such as aviation and marine shipping. Transesterification of non-edible oils is a well-established route to biodiesel as a versatile liquid transport fuel, but is challenging to scale using existing homogeneous liquid base catalysts. In this work, we report the synthesis, characterisation, and application of silica-supported MgO solid base catalysts for triglyceride transesterification with methanol and highlight the impact of silica pore structure on performance. True liquid crystal templating enables the one-pot synthesis of mesoporous MgO/SBA-15 catalysts with variable Mg content, or hierarchical macroporous–mesoporous MgO/SBA-15 analogues through the addition of polystyrene nanospheres. Both MgO/SBA-15 families exhibit highly ordered pore networks; however, ~280 nm macropores stabilise Mg-O-Si interfacial species even at high Mg loading, in contrast to the mesoporous support that permits sintering of ~14 nm MgO nanocrystals. Hierarchical porous MgO/SBA-15 catalysts exhibit higher specific activity and conversion of tributyrin to methyl butyrate than their mesoporous analogues (3 mmol⋅h⁻¹⋅g⁻¹ versus 2 mmol⋅h⁻¹⋅g⁻¹ at 60 °C and 11 wt% Mg). The magnitude of this rate enhancement increases with triglyceride chain length, being approximately three-fold for trilaurin (C₁₂) transesterification at 90 °C, attributed to superior in-pore mass transport of bulky reactants through the hierarchical porous catalyst. Full article

The port of Gaženica, managed by the Port Authority of Zadar, is open to public traffic of special economic interest to the Republic of Croatia. Situated outside Zadar’s city centre, with convenient access to the airport and A1 highway, this port presents significant opportunities for Zadar County’s economic growth. While also serving as a cargo and fishing port, as the second-largest passenger port in Croatia, the port of Gaženica prioritises the development of cruise ship traffic. The expansion of intermodal traffic is being facilitated through the development of a multipurpose terminal to accommodate general, roll-on/roll-off, and containerised cargo (full and empty containers). The rising number of passenger ships—particularly cruise ships—along with the increasing passenger, vehicle, and cargo traffic, poses a significant risk of pollution due to dust, noise, greenhouse gases, and other pollutants. Considering these risks, the use of alternative energy sources, decarbonisation of maritime transport, the separation of waste by type, and the proper handling and disposal of ship waste are of utmost importance. The aim of this study is to present and analyse the green transition process of the port of Gaženica through the results that have been achieved or are yet to be achieved through the implementation of green projects by the Port Authority of Zadar. For this purpose, a mixed-methods approach combining project analysis and the qualitative analysis of emissions data is used. It is important to highlight that the method of interviews with relevant representatives of institutions involved in the project was also used to gain insight into financial and infrastructural challenges, the accessibility of certain data, and potential improvements in implementation. The research results indicate that the port of Gaženica has completed four green projects, while another four are currently being implemented, with their completion expected by 2026. The research concludes that it is necessary to strengthen environmental awareness regarding proper waste disposal among all stakeholders in maritime transport, including the local community, businesses, and local authorities. The results demonstrate a need to focus on certification with the aim of strengthening the green transition process through involvement in the EcoPorts and Green Award certification schemes. It is also necessary to actively improve the public availability of data from the base station in the port of Gaženica to inform the public about environmental impacts in real time (24/7) while facilitating data collection for statistical reporting purposes. Full article

Climate change is fuelled by the continued growth of global carbon emissions, with the widespread use of fossil fuels being the main driver. To achieve a decarbonisation transition of the energy mix, the development of clean and renewable fuels has become crucial. Ammonia is seen as an important option for decarbonisation in the transport and energy sectors due to its zero-carbon emission potential and renewable energy compatibility. However, the high energy consumption and carbon emissions of the conventional Haber–Bosch method limit its sustainability. A green ammonia synthesis system was designed using ECLIPSE and Excel simulations in the study. Results show that at a recirculation ratio of 70%, the system’s annual total energy consumption is 426.22 GWh, with annual ammonia production reaching 8342.78 t. The optimal system configuration comprises seven 12 MW offshore wind turbines, integrated with a 460 MWh lithium battery and 240 t of hydrogen storage capacity. At this configuration, the LCOE is approximately £5956.58/t. It shows that incorporating renewable energy can significantly reduce greenhouse gas emissions, but further optimisation of energy storage configurations and reaction conditions is needed to lower costs. This research provides a reference for the industrial application of green ammonia in the transportation sector. Full article

Background: The pressure on the transport sector to decarbonise intensifies the need to look beyond the usual recommendations (e.g., walking, cycling, technological innovations). Therefore, strategies to avoid or modify commutes to places of work have long been seen as an option to decarbonise. Recognised for achieving an optimal balance between working from home and working in an office, co-working spaces may also minimise the length of commutes and therefore reduce emissions, traffic congestion, road maintenance, stress experienced by drivers, and other negative externalities of traffic. Methods: This study quantifies the above using a digital model of England and Wales. Two distributions of co-working spaces have been compared in this paper (i.e., one co-working space (i) in each Middle-layer Super Output Area or (ii) at the nearest train station). Results: The overall reduction in travel time and distance exceeds 70% if everyone who commutes by car outside their home MSOA drives to a co-working space. Despite a change in the place of work having no impact on the cold start emissions, substantial emission savings can still be achieved. These range from 35.8% to 92.1% depending on the pollutant, scenario, and distribution of co-working spaces. Full article

This study presents a comprehensive assessment of the energy systems in eight Eastern European countries—Bulgaria, Croatia, the Czech Republic, Hungary, Poland, Romania, Slovakia, and Slovenia—focusing on their energy transition, security of supply, decarbonisation, and energy efficiency. Using principal component analysis (PCA) and clustering techniques, we identify three different energy profiles: countries dependent on fossil fuels (e.g., Poland, Bulgaria), countries with a balanced mix of nuclear and fossil fuels (e.g., the Czech Republic, Slovakia, Hungary), and countries focusing mainly on renewables (e.g., Slovenia, Croatia). The sectoral analysis shows that industry and transport are the main drivers of energy consumption and CO₂ emissions, and the challenges and policy priorities of decarbonisation are determined. Regression modelling shows that dependence on fossil fuels strongly influences the use of renewable energy and electricity consumption patterns, while national differences in per capita electricity consumption are influenced by socio-economic and political factors that go beyond the energy structure. The Decarbonisation Level Index (DLI) indicator shows that Bulgaria and the Czech Republic achieve a high degree of self-sufficiency in domestic energy, while Hungary and Slovakia are the most dependent on imports. A typology based on energy intensity and import dependency categorises Romania as resilient, several countries as balanced, and Hungary, Slovakia, and Croatia as vulnerable. The projected investments up to 2030 indicate an annual increase in clean energy production of around 123–138 TWh through the expansion of nuclear energy, the development of renewable energy, the phasing out of coal, and the improvement of energy efficiency, which could reduce CO₂ emissions across the region by around 119–143 million tons per year. The policy recommendations emphasise the accelerated phase-out of coal, supported by just transition measures, the use of nuclear energy as a stable backbone, the expansion of renewables and energy storage, and a focus on the electrification of transport and industry. The study emphasises the significant influence of European Union (EU) policies—such as the “Clean Energy for All Europeans” and “Fit for 55” packages—on the design of national strategies through regulatory frameworks, financing, and market mechanisms. This analysis provides important insights into the heterogeneity of Eastern European energy systems and supports the design of customised, coordinated policy measures to achieve a sustainable, secure, and climate-resilient energy transition in the region. Full article

Decarbonisation of urban energy and transportation systems has become a priority for cities worldwide, with policies primarily aiming to promote rooftop solar electricity generation and a shift to private electric vehicles (EVs). However, these policies may also increase inequalities in access to affordable, low-carbon mobility and the associated benefits. While academic literature shows increasing awareness of these equity impacts and risks, the extent to which this applies to policy practice remains unclear. We therefore conducted a case study of seven Dutch cities, analysing local policy documents and conducting interviews with policymakers. The study provided insight into the current policy landscape and revealed a general sensitivity among interviewed policymakers to possible equity impacts of the current decarbonisation policies. Only a few measures to address these impacts are currently in place, but policymakers have proposed a range of novel and more inclusive measures, which can be tested for their impacts and scaling potential in real-life experiments. Another priority for future research is exploring the potential of shared electric mobility to provide equitable access to low-carbon transportation. Full article

Inland Waterway Transport (IWT) is widely recognised as an energy-efficient freight mode, yet its decarbonisation is increasingly constrained not by propulsion technology, but by the absence of infrastructure capable of delivering clean energy where and when it is needed. This paper presents a structured review of over a decade of academic, policy and technical literature, identifying systemic gaps in current decarbonisation strategies. The analysis shows that most pilot projects are vessel-specific, and poorly scalable, with infrastructure planning rarely based on vessel-level energy demand data, leaving energy provision as an afterthought. Current approaches overemphasise technology readiness while neglecting the complexity of aligning supply chains, operational diversity, and infrastructure deployment. This review reframes IWT decarbonisation as a problem of provision, not propulsion. It calls for demand-led, demand driven, fuel agnostic infrastructure models and proposes a roadmap that integrates technical, operational, and policy considerations. Without rethinking energy access as a core design challenge—on par with vessel systems and regulatory standards—the sector risks investing in stranded assets and missing climate and modal shift targets. Aligning vessel operations with dynamic, scalable energy delivery systems is essential to achieve a commercially viable, fully decarbonised IWT sector. Full article

Additive manufacturing (AM), or 3D printing, is increasingly recognised as a disruptive production technology with the capacity to reduce greenhouse gas (GHG) emissions across manufacturing and transportation sectors. By enabling material efficiency, lightweighting, part consolidation, and decentralised, on-demand production, AM offers pathways to lower embodied energy, minimise waste, and shorten supply chains. This review critically evaluates AM’s role in decarbonisation, with a focus on clean transportation applications, including electric vehicles, fuel cells, and hydrogen storage systems. Case studies quantify energy savings, operational efficiency gains, and life-cycle GHG reductions compared to conventional manufacturing routes. The analysis also addresses technical and economic limitations—such as material availability, scalability, certification, and cost competitiveness—and explores synergies with circular economy principles, digital design optimisation, and artificial intelligence. Policy recommendations and industry–academia collaboration models are proposed to accelerate AM adoption, integrate renewable energy sources, and strengthen recycling infrastructure. By synthesising technical, economic, and policy perspectives, the study positions AM as a critical enabler of net-zero manufacturing and a catalyst for sustainable industrial transformation. Full article