Japan Petroleum Energy Center has been conducting research and development of the integrated synthetic fuel production technology and fuel utilization technology with industry, academia, and government. The characteristics of fuel quality and conformity to fuel regulations were investigated for European commercial synthetic fuels and biofuel. In addition, the fuel properties of FT crude oil with Co-based FT catalyst were analyzed, and the direction of catalyst technology and upgrading processing to improve the fuel quality for use as automotive fuel was understood. Based on these results, we summarized the issues to be solved for the use of synthetic fuels as automobile fuels.

Research and development of hydrogen engines as a power source for heavy duty vehicles is progressing rapidly, especially in Europe. This paper describes the issues that became clear through testing of a hydrogen engine developed by author's group and demonstration testing of a truck equipped with the engine. Many technical challenges remain, such as reducing the hydrogen concentration in the crankcase, reducing engine oil consumption and so on, but these are thought to be solved by engine technology developed for conventional engines. However, in Japan, hydrogen cost is thought to be the biggest barrier to practical use of hydrogen engines.

The inclusion of bio-fuels into forecourt fuel can provide a very significant impact on sustainability and carbon neutrality targets. Many regions now mandate a minimum level of bio-fuel content with one such example being India's accelerated adoption of E20 (20% ethanol in gasoline). The properties of bio-fuels are different to those of conventional mineral fuels resulting in detrimental effects to performance in a number of areas. The lubricant plays a critical role in ensuring that internal combustion engines continue to operate effectively in the presence of bio-fuels and this study aims to highlight the effects of increased ethanol content in gasoline. Results show that ethanol has a tendency to increase deposits and wear, and that selection of an appropriate additive package can help to mitigate these effects.

In Japan, carbon dioxide emissions from the aviation sector account for approximately 5% of the total transportation sector. The trend towards carbon neutrality in the aviation sector is to achieve this through a combination of improved flight operations, the introduction of new technologies, and the use of sustainable aviation fuel. Sustainable aviation fuel (SAF) is currently the most feasible option, and has already begun to be distributed. This paper describes the trends surrounding SAF and efforts toward its production and supply.

Preventing air pollution and reduction of GHG (Green House Gas) have become urgent issues in the international shipping industry, and regulations on emissions of nitrogen oxides (NOx), sulfur oxides (SOx) and particulate matter (PM) have been gradually strengthened in IMO (International Maritime Organization) MARPOL Annex VI. In addition, GHG emission regulations have also been strengthened, and the shift from traditional fossil fuels to alternative fuels such as methanol and ammonia should be accelerating to achieve the goal of zero GHG emissions from international shipping by 2050. Since alternative fuels do not contain sulfur, Category II cylinder oils, which are beginning to be introduced for large marine 2-cycle engines for low-sulfur fuel oil, could become a suitable solution for alternative fuels.

In July 2023, the International Maritime Organization (IMO) set a goal of zero greenhouse gas (GHG) emissions from international shipping by around 2050. In addition, new goals were agreed upon to introduce 5-10% zero-emission fuels by 2030, reduce carbon dioxide (CO₂) emissions per unit of transportation by 40% (compared to 2008), and reduce GHG emissions by 20-30%. To achieve this goal, it is necessary to convert marine fuels to low-carbon or decarbonized fuels, and synthetic methane is one of the candidate fuels. Synthetic methane is produced from hydrogen generated from renewable energy and carbon dioxide emitted by industry. It is also important to reduce CO₂emissions in each process of producing synthetic methane. Using synthetic methane produced by methanation technology as next-generation marine engine fuel can greatly contribute to carbon neutrality.

In this study, we elucidated the lubricating effect of liquid-phase nanocarbon coating films on stainless steel substrates with soluble carbon material (SCM). SCM showed a lubricating effect that forms a tribo-film on the stainless steel substrate through a tribo-chemical reaction caused by sliding (COF was 0.17-0.18). Tribo-chemical reactions did not proceed at a load of 0.98 N, but at a load above 9.8 N On the other hand, the lubricity of the carbonized SCM film formed by heating the SCM film to 400°C was worse (COF was 0.22-0.23). Therefore, the film formed by the tribo-chemical reaction was more effective in improving lubricity than the film formed by the thermal-chemical reaction. In the thermal-chemical reaction, etherification and furan cyclization reactions proceeded as previously reported, and in the tribo-chemical reaction, in addition to anisotropic reactions in the sliding direction, carbonization with benzene ring opening reactions proceeded, forming tribo-films. This innovative liquid-phase nanocarbon coating technology enables easy and lubricious coating and provides an alternative solution to existing gas-phase coatings.

Plasma is a high energy state, where hydrocarbon molecules are excited, ionized, and decomposed to evolve hydrogen. Previously, we investigated experimentally decomposition characteristics of various types of hydrocarbon compounds by attack of the discharge plasma, and found that no discharge plasma followed by the hydrogen evolution are generated for the compounds with the electrical resistivity below 1.1×10⁷Ω・m. In this study, we focused our target on the aromatic hydrocarbon compounds with two benzene rings and an aliphatic hydrocarbon group between them evolved a small, and even an extremely small amount of hydrogen depending on the length of the aliphatic group. The shorter the aliphatic hydrocarbon, the shorter the discharge period and the less hydrogen was evolved. When voltage was applied to such compounds, discharge occurred only in the initial period, and then the voltage dropped to a stable conduction level. Furthermore, after repeated voltage application tests, it was confirmed that black powders were generated. SEM and Raman analyses showed that the black powders had some properties like carbon black. Thus, it has been concluded that the aromatic compounds are locally decomposed to produce conductive carbon particles by the attack of discharge plasma, thereby avoiding the discharge phenomenon.