Alternative Fuels Research Articles

Improving Green Shipping by Using Alternative Fuels in Ship Diesel Engines

This paper aims to consider the issue of increasing the environmental friendliness of shipping by using alternative fuels in marine diesel engines. It has been determined that marine diesel engines are not only the main heat engines used on ships of sea and inland waterway transport, but are also sources of emissions of toxic components with exhaust gases. The main compounds whose emissions are controlled and regulated by international organizations are sulfur oxides (SOX) and nitrogen oxides (NOX), as well as carbon dioxide (CO2). Reducing NOX and CO2 emissions while simultaneously increasing the environmental friendliness of shipping is possible by using fuel mixtures in marine diesel engines that include biodiesel fuel. During the research carried out on Wartsila 6L32 marine diesel engines (Shanghai Wartsila Qiyao Diesel Co. Ltd., Shanghai, China), RMG500 and DMA10 petroleum fuels were used, as well as their mixtures with biodiesel fuel FAME. It was found that when using mixtures containing 10–30% of FAME biodiesel, NOX emissions are reduced by 11.20–27.10%; under the same conditions, CO2 emissions are reduced by 5.31–19.47%. The use of alternative fuels in marine diesel engines (one of which is biodiesel and fuel mixtures containing it) is one of the ways to increase the level of environmental sustainability of seagoing vessels and promote ecological shipping. This is of particular relevance when operating vessels in special ecological areas of the World Ocean. The relatively low energy intensity of the method of creating and using such fuel mixtures contributes to the spread of its use on many means of maritime transport.

One-pot bioconversion of fungal lipid to mycodiesel: a sustainable approach.

The conversion of filamentous fungus-based feedstock into Biodiesel holds potential as a sustainable and eco-conscious method for producing alternative liquid fuels. This study examined the comparison of individual Fatty Acid Methyl Esters (FAME) of Aspergillus niger and Curvularia lunata with the consortium of both filamentous fungal cocktail Fatty acid methyl esters (cFAME), following a transesterification process that turned the fungal lipids into myco-based biodiesel productions. cFAME weighs 23.89g and accumulates to 20.43g of lipid yield, with 86% of cellular lipids; in contrast, A. niger weighs 12.65g and pile up 9.5g of lipid yield, with 75% of cellular lipid, also C. lunata exhibits 8.35g of dry weight with 4.89g of lipid concentration, with 59% of cellular lipids. A. niger was known to contain C16-C18 saturated and unsaturated fatty acids possess LAME (C18:2), OAFA (C18:1), and PAME (C16:0) were shown in high percentages accounted for 86.6% in A. niger. The results showed that PUFA was predominant over MUFA and SFA. C. lunata chiefly produces C16 and C18 fatty acids, which are considered favorable for combustion properties with oleic acid (C18:1), linoleic acid (C18:2), palmitic acid (C16:0), and stearic acid (C18:0), on the comparison. However, the FAME profile of C. lunata occupies only 39.07% of the biodiesel quality. Pentadecanoic acid, palmitic acid, palmitoleic acid, Oleic acid, Linolenic acid, Linoleic acis, and Hexanoic acid with the carbon range of C6:0 - C18:3 were observed in cFAME. Based on the biodiesel yield, cFAME scored 20.55%, whereas A. niger with 11.05 and C.lunata 2.45%, respectively. The presence of methyl esters containing various long-chain fatty acids indicates very effective biodiesel assets, as confirmed by GC-MS analysis, which evidenced ignition efficiency, among others. cFAMEs were impacted by high ignition efficiency with > 4min. Consortium strategies seize attention in different dimensions and have been confirmed by their upregulation in their fatty acid profiles; in the future, the combination of high lipid holders among the fungal kingdom can be an alternative in myco-based biodiesel production.

Corrosion analysis of stainless steel exposed to Karanja oil biodiesel: a comparative study with commercial diesel fuel, surface morphology analysis, and long-term immersion effects in alternative fuels

Abstract The ever-growing energy demand necessitates the deployment of renewable alternatives as fossil fuel reserves diminish. The biodiesel generated from these non-edible feedstocks, such as Karanja, and Jatropha oils, offers an environmental alternative without affecting food security. Transesterification process (using methanol as solvent and sodium hydroxide (NaOH) catalyst) was used to prepare biodiesel. The stainless steel, mild steel, and cast iron materials were immersed in Karanja oil biodiesel blends (B80 and B90) and commercial diesel for 1872 h at 37 °C to critically examine the corrosion behavior with their comparison analysis. It was unveiled that biodiesel is more prone to corrosion than diesel fuel under comparable identical conditions. The corrosion rates determined by weight loss measurements in biodiesel were found to range from 0.0173 mm/year to 0.0194 mm/year for stainless steel, 0.03076 mm/year to 0.03232 mm/year for mild steel, and from 0.0505 mm/year to 0.0528 mm/year for cast iron, as compared to 0.009 mm/year for stainless steel, 0.015 mm/year for mild steel, and 0.017 mm/year respectively for cast iron in diesel. The intense severe melting of biodiesel as compared to diesel samples can be determined by employing the SEM analysis at 200X and 400X magnification scales. Hence, this study has underscored the significance of selecting the appropriate corrosion resistant materials that are suitable for the continued prolonged storage and utilization or application biodiesel.

Carbon emissions from road transport on a national neonatal transport service: a retrospective observational study

We conducted a retrospective observational study of all transports conducted by our national neonatal transport service to estimate direct carbon emissions produced by the service in a 1 year time...

Decarbonization of Energy Operations for Hard-to-Abate Industries Through Smart Energy System Optimization

Abstract Hard-to-abate industries such as cement, steel, and chemical production are major contributors to carbon dioxide (CO2) emissions due to its energy intensive and hard-to-abate nature. The high-temperature process during the conversion of limestone into clinker in cement production results in significant process emissions. To achieve net-zero emission target, the industries are exploring various strategies, including reducing indirect emissions by using renewable energy, improving energy efficiency through waste heat recovery, adopting alternative low carbon fuels, and implementing carbon capture units. In this paper, a multiperiod mixed-integer linear programming model that integrates the aforementioned strategies is formulated to investigate their interaction in smart energy system. The smart energy system involves renewable energy, storage, waste heat recovery, and combined heat and power units. Two scenarios under one case study have been conducted. The first focuses on the technology selection under scenarios with different cement production scales whereas the second concentrates on the effect of energy storage in smart energy storage and CO2 emission reduction plans in the cement industry. The developed mathematical model can choose to either use alternative low carbon fuels to replace fossil fuels in kilns or implement a carbon capture unit as the CO2 emission reduction plan. Optimization is carried out to minimize the total annualized cost for both scenarios. The findings indicate that by implementing the proposed smart energy system with the lowest total annualized cost, the cement industry has the potential to achieve a reduction of up to 20% in CO2 emissions. Further reduction in CO2 emissions requires the implementation of carbon capture unit. Graphical Abstract

Pneumatic Vehicle

A pneumatic vehicle is an innovative transportation system that operates using compressed air as its primary energy source. Unlike conventional vehicles that rely on fossil fuels, pneumatic vehicles utilize stored air to drive pistons or turbines, generating motion. This eco-friendly alternative reduces greenhouse gas emissions, noise pollution, and dependence on non-renewable energy sources. The key components of a pneumatic vehicle include air tanks, compressors, and pneumatic motors, which work together to efficiently convert air pressure into mechanical energy. Although challenges such as limited energy storage and refueling infrastructure exist, advancements in air compression technology and hybrid pneumatic-electric systems continue to improve their feasibility. With applications in urban transportation, industrial vehicles, and hybrid energy systems, pneumatic vehicles represent a promising step toward sustainable mobility. Keywords: Pneumatic vehicle, compressed air engine, eco-friendly transportation, sustainable mobility, air-powered car, renewable energy, green technology, alternative fuels, air compression, zero-emission vehicle.

Hydrogen as a Sustainable Fuel: Transforming Maritime Logistics

The marine industry, being the backbone of world trade, is under tremendous pressure to reduce its environmental impact, mainly driven by reliance on fossil fuels and significant greenhouse gas emissions. This paper looks at hydrogen as a transformative energy vector for maritime logistics. It delves into the methods of hydrogen production, innovative propulsion technologies, and the environmental advantages of adopting hydrogen. The analysis extends to the economic feasibility of this transition and undertakes a comparative evaluation with other alternative fuels to emphasize the distinct strengths and weaknesses of hydrogen. Furthermore, based on case studies and pilot projects, this study elaborates on how hydrogen can be used in real-world maritime contexts, concluding that the combination of ammonia and green hydrogen in hybrid propulsion systems presents increased flexibility, with ammonia serving as the primary fuel while hydrogen enhances efficiency and powers auxiliary systems. This approach represents a promising solution for reducing the shipping sector’s carbon footprint, enabling the industry to achieve greater sustainability while maintaining the efficiency and scalability essential for global trade. Overall, this work bridges the gap between theoretical concepts and actionable solutions, therefore offering valuable insights into decarbonization in the maritime sector and achieving global sustainability goals.

Chemical products yielded from different pyrolysis processes of rice waste residues: a comprehensive review

Abstract Researchers are conducting extensive research on renewable energy sources to offset the decline in petroleum-based products. It is becoming more and more important to use biomass as a source of energy and renewable fuels. The most promising method for converting biomass into alternative energy in the forms of biochar, biooil, combustible gases, and other important compounds is pyrolysis. To produce such important alternative fuels in an efficient and cost-effective manner, biomass is thermochemically broken down without the presence of oxygen. The vast amount of biomass that comprises rice waste, including husk, bran, and straw, makes it the perfect feedstock for biomass conversion. First, rice waste is synthesized and used for the production of bio-char and biofuels, which are alternatives to fossil fuels. The conversion of rice waste into platform chemicals is then emphasized as a way to use the current industrial facilities to produce sustainable chemical production using renewable carbon feedstocks. Additional uses for rice waste bio-char include the production of bio-diesel, bio-methane, biohydrogen, sugars (xylose and glucose), furan derviatives, organic acids, and aromatic hydrocarbons (benzene, toluene, etc.). This review examines the outcomes of rice pyrolysis, equipment and operating parameters, the composition of bio-oil, the chemical composition of rice wastes, and their heating value from the perspective of research on biomass pyrolysis. The review demonstrates that the primary operating parameters that impact the quantity and quality of yields are the pyrolysis temperature, inert gas sweeping rate, residence durations, heating rate, particle size, catalysts, pre-washing, and equipment employed, among others. An empirical formula for HHV based on the elemental analysis of rice residue with reasonably high accuracy is presented. Also, comparisons between the different yield types from different pyrolyzed reactors are introduced and discussed. Future research on rice waste valorization for the sustainable production of chemicals and fuels will be guided by the issues and opportunities that are outlined here.

Financial and Legal Implications of the Development of Electromobility for the National State Budget

This article focuses on the analysis of the impacts of the development of electromobility on national state budget revenues. In the first part, it provides a brief overview of alternative fuels and the current stage of electromobility development. The next part elaborates the legal framework of electricity taxation from the perspective of European legislation and national legislation of the Slovak Republic. In order to provide a comprehensive view of the impact of the development of electromobility on the state budget, part of this thesis is also devoted to a comparison of the Slovak national legislation and the Czech national legislation on the taxation of electricity consumption. The final part will assess the identified financial and legal impacts of the development of electromobility on public finances and makes a proposal of de lege ferenda.

Ketogenesis nutritionally supports brain during bacterial infection in Drosophila.

Ketogenesis nutritionally supports brain during bacterial infection in Drosophila.

Control of regulated and unregulated emissions of an automotive spark ignition engine with alternative fuels (methanol, ethanol and hydrogen)

Control of regulated and unregulated emissions of an automotive spark ignition engine with alternative fuels (methanol, ethanol and hydrogen)

Bioenergy production from yeast through a thermo-chemical platform.

Bioenergy production from yeast through a thermo-chemical platform.

The contribution of shipping to the emission of water and air pollutants in the northern Adriatic Sea - current and future scenarios.

The contribution of shipping to the emission of water and air pollutants in the northern Adriatic Sea - current and future scenarios.

Life cycle assessment of ammonia and hydrogen as alternative fuels for marine internal combustion engines

Life cycle assessment of ammonia and hydrogen as alternative fuels for marine internal combustion engines

Designing a Probable Engine for Future Supersonic Transport Aircraft

Supersonic transport (SST) is poised to revolutionize the aviation industry once again, offering the potential for significantly reduced travel times across transcontinental and transoceanic routes. This paper delves into the key engine design elements for next-generation SST aircraft, focusing on critical areas such as fuel efficiency, environmental sustainability, and noise reduction. With a particular emphasis on low-bypass turbofan engines, variable cycle technology, and afterburner integration, this paper provides a comprehensive analysis of the technological advancements necessary to address the challenges that previously plagued supersonic transport, such as the high fuel consumption and environmental impact of earlier designs like the Concorde [1]. The paper also explores the role of alternative fuels—namely, sustainable aviation fuel (SAF) and liquid hydrogen—and their implications for the future of high-speed aviation. Through computational modeling and materials analysis, the paper proposes a conceptual engine model that balances performance, sustainability, and regulatory compliance. Areas for future research, particularly in noise abatement and thermodynamic efficiency, are also outlined.

Solutions to increase the use of alternative fuels in cement clinker production

Solutions to increase the use of alternative fuels in cement clinker production

Investigating the Combustion Performance of Dual Fuel Combustion With Diesel and Port Injected Hydrogen in A Large Bore Locomotive Engine

Abstract The heavy-duty transportation sector has primarily relied on conventional diesel combustion engines given their reliability and high thermal efficiency relative to spark ignition engines, but increased focus on reducing greenhouse gas emissions has led to investigation into alternative fuels. Gaseous hydrogen fuel has garnered a great deal of recent interest in the engine community given it has zero carbon, but hydrogen is not available at the scale and cost that petroleum fuels are currently available, and this is a barrier to adoption for industries that are looking to decarbonize their operations. Because of the fuel flexibility provided, dual fuel technology offers a pathway for some industries to adopt hydrogen as a fuel source while maintaining sufficient flexibility in times and locations where the new fuel is not yet available. This computational study investigates dual fuel combustion in a large bore locomotive engine architecture using direct injected diesel and port injected gaseous hydrogen fuel. With an optimal port fuel injection configuration from previous work, simulations of varying substitution ratio, compression ratio, manifold air temperature, diesel injection timing, and diesel injection pressure were performed to understand their effect on combustion performance. Results indicated that both increased substitution ratio and higher intake air temperature accelerates hydrogen flame propagation and can result in high peak cylinder pressures. Additionally, diesel injection timing and injection pressure were demonstrated as effective methods for controlling dual fuel combustion heat release rates.

Improved Engine Data Acquisition System and Interface to Enable Experimentation With Emerging Alternative Fuels in a Spark-Ignited Cooperative Fuel Research Engine

Abstract In the face of new engine research challenges, legacy hardware and once state-of-the-art assumptions may become less relevant, especially those made due to the computational limitations of the hardware at the time of initial development. Such legacy elements can potentially limit the effectiveness of accurately describing key parameters or metrics during experimentation or postprocessing. As the behavior of novel fuels is also not always fully understood, this highlights the need for tools to guide the experimental design to avoid unexpected and potentially dangerous outcomes. This paper details the conversion of an existing data acquisition system for a spark-ignited single-cylinder cooperative fuel research (CFR) engine to handle a variety of different emerging alternative fuels. Modifications to the in-house legacy LabVIEW program and data acquisition system are detailed, with emphasis on providing additional tools to aid in the experimentation expediency and safety. The existing CFR testing facility is converted from a single liquid or single gaseous fuel capable system to a multifuel compatible system, complete with on-the-fly calculations of mass, energy, and volume fractions of existing fuel blends, increased low-speed sampling rates, and a calculating tool to command fuel flow set-points for a given blend fraction, equivalence ratio and airflow set-point. Additional factors, such as sensor selection and communication, are discussed with an emphasis on reducing experimental uncertainty. Overall, this work provides insights into possible adjustments and considerations when upgrading existing experimental setups to accommodate emerging alternative fuel use.

Blue Ammonia and the Supply Chain Pioneering Sustainability Assessment for a Greener Future

With the global shift to sustainability, the energy sector faces pressure to adopt low-carbon solutions. Blue ammonia (BA), derived from natural gas (NG) with carbon capture, presents significant opportunities but requires a holistic sustainability assessment. This study conducts a novel life cycle sustainability assessment (LCSA) of BA, evaluating environmental, economic, and social impact performance from feedstock processing to maritime transport for a 1.2 MMTPA production capacity. Process simulations in Aspen HYSYS V12 and the ammonia maritime transport operations’ sustainability assessment model provide critical insights. The ammonia converter unit contributes the highest emissions (17.9 million tons CO2-eq), energy use (963.2 TJ), and operational costs (USD 189.2 million). CO2 removal has the most considerable land use (141.7 km2), and purification records the highest water withdrawal (14.8 million m3). Carbon capture eliminates 6.5 million tons of CO2 annually. Economically, ammonia shipping dominates gross surplus (USD 653.9 million, 72%) and tax revenue (USD 65.3 million) despite employing just 43 workers. Socially, the ammonia converter unit has the highest human health impact (16,621 DALY, 54%). Sensitivity analysis reveals transport distance (46.5% CO2 emissions) and LNG fuel prices (63.8% costs) as key uncertainties. Findings underscore the need for optimized logistics and alternative fuels to enhance BA sustainability.

Numerical Investigation of Ammonia/n-Heptane Dual-Fuel Spray Flames Using Large-Eddy Simulations

Abstract Diesel engines are extensively used in heavy-duty transportation, power generation, and marine vehicles due to their superior thermal efficiency and extended high-load operability compared to spark ignition (SI) engines. However, combustion in diesel engines is generally characterized by locally rich fuel-air mixtures and high combustion temperatures, causing significant amounts of soot and NOx emissions from these engines. Utilizing carbon-free alternative fuels and enhancing fuel efficiency represent promising strategies to mitigate greenhouse gas (GHG) and other emissions in the heavy-duty transportation sector. In this context, ammonia (NH3), as a hydrogen carrier, has received significant attention as a viable substitute for hydrocarbon fuels, due to its carbon-free composition, relatively high energy density, and well-established infrastructure. Many previous studies have considered combustion and emission characteristics of ammonia-hydrocarbon fuel blends in engines and simplified flames. However, detailed investigations on the effect of ammonia on the performance of hydrocarbon fuels under engine conditions are lacking. In the present study, we perform large-eddy simulations (LES) of the ignition and flame processes in a constant volume combustion reactor, where n–heptane is injected in an ammonia/air ambient mixture in a diesel-like environment. A detailed and validated reaction mechanism containing 302 species and 1981 reactions is employed. The ECN Spray H experimental data is used to validate the spray model under non-reacting and reacting conditions. Dual-fuel combustion is simulated using the well-stirred reactor (WSR) approach. Results are presented for two spray cases: (1) Single fuel (SF) with n-heptane injected into a mixture of air and combustion products; (2) Dual-fuel (DF) with the injection of n-heptane in a mixture of air, ammonia, and combustion products. It is observed that the presence of ammonia has a significant effect on the ignition and flame development processes. With ammonia addition, both the first and second stage ignition delay times increase, but the effect of ammonia on the second stage ignition is significantly more prominent. In addition, the ignition kernel size and growth rate decrease noticeably. For SF spray, the main ignition is characterized by multiple ignition kernels near spray tip, whereas for DF spray, a single relatively small ignition kernel forms and grows slowly in the downstream direction. The flame development and the final quasi-steady flame structure are also modified due to ammonia. The outcome of this research would enable better understanding of ammonia-diesel dual-fuel spray flame behavior and guide development of associated engine combustion strategies.