Investigation on Fuel Properties of Synthetic Gasoline-like Fuels

Article Investigation on Fuel Properties of Synthetic Gasoline-like Fuels Weidi Huang 1,2, Koichi Kinoshita 1,*, Yohko Abe 1, Mitsuharu Oguma 1, and Kotaro Tanaka 2,3 1 Research Institute for Energy Conservation, National Institute of Advanced Industrial Science and Technology, 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564, Japan 2 Carbon Recycling Energy Research Centre, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511, Japan 3 Graduate School of Science and Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511, Japan * Correspondence: koichi-kinoshita@aist.go.jp     Received: 8 November 2023 Accepted: 25 March 2024 Published: 27 March 2024   Abstract: Synthetic fuels have gained considerable attention due to their promising characteristics. A comprehensive survey was undertaken to assess the availability of synthetic fuels in the global market, followed by an investigation to evaluate their potential in engines. This report presents the initial findings regarding the physical and chemical properties of synthetic gasoline-like fuels, specifically DMC (dimethyl carbonate), bioethanol, EtG (ethanol-to-gasoline), G40, and bio-naphtha. A comparison was conducted between these synthetic fuels and conventional gasoline. Furthermore, discussions were provided to enhance the understanding of the potential influence of fuel properties on spray and combustion characteristics. EtG and G40 are specifically designed to emulate conventional gasoline. Results indicate that EtG and gasoline should be directly interchangeable in the engine or blended in any proportion because they have almost identical Research Octane Number (RON)/Motor Octane Number (MON), fuel density, and higher heating value (HHV). G40 has a higher RON (105) compared with that of gasoline (92.2), likely resulting from the high content of iso-paraffin in G40. Bio-naphtha exhibits the high fraction of paraffin and naphthene content relative to other fuels. The feature of chemical compositions results in a lower RON (55.9), lower HHV and smaller fuel density compared to other fuels. DMC and bioethanol blends in gasoline were investigated. Regardless of whether DMC or bioethanol is incorporated, under a 60% blend ratio, gasoline distillation accelerates initially, until DMC or bioethanol completely evaporates, after which gasoline distillation returns to its normal rate. With increasing the volumetric fraction of the ethanol in the blends, either chemical compositions or the RON/HHV basically change linearly.