Combustion and Exhaust Gas Characteristics of a Spark-Ignition Engine using Carbon Neutral Fuels (MtG: Methanol to Gasoline, EtG: Ethanol to Gasoline)

Chihiro Kishimoto･Haruto Morimoto･Ratnak Sok (Waseda University)･Kou Osada･Ryota Yamada (Toyota Motor)･Jin Kusaka (Waseda University)

This research experimentally investigates the effects of MtG and EtG on combustion and exhaust characteristics in spark-ignition engines from low to high load ranges. No differences were observed in brake thermal efficiency between fuel types. However, differences were confirmed in exhaust gas composition. This suggests that the influence of each fuel's evaporation characteristics on the mixture formation process is a contributing factor.

Combustion and Exhaust Gas Characteristics of a Spark-Ignition Engine using Ethanol-Blended Carbon Neutral Fuel (MtG: Methanol to Gasoline)

Haruto Morimoto･Chihiro Kishimoto･Ratnak Sok (Waseda University)･Kou Osada･Ryota Yamada (Toyota Motor)･Jin Kusaka (Waseda University)

This research investigates the effects of adding ethanol to gasoline and MtG on engine performance by engine dynamometer testing. Ethanol addition enabled ignition timing advance, resulting in improved brake thermal efficiency. Furthermore, CO, NO, and THC emissions were reduced. No significant difference in ethanol addition sensitivity was observed between gasoline and MtG.

Construction of a Chemical Kinetic Mechanisms for Carbon Neutral Fuels (MtG: Methanol to Gasoline, EtG: Ethanol to Gasoline) in Spark-Ignition Engines

Chihiro Kishimoto･Haruto Morimoto･Ratnak Sok (Waseda University)･Kou Osada (Toyota Motor)･Jin Kusaka (Waseda University)

This research investigates the combustion characteristics of gasoline, MtG, and EtG by experiments using constant-volume combustion chamber and detailed chemical reaction analysis. It was confirmed that MtG and EtG tend to exhibit lower laminar flame velocities and lower adiabatic flame temperatures compared to gasoline. Sensitivity analysis showed that heavy aromatic components in the fuels were the cause of the decrease in laminar flame speed.

Synthetic Gasoline Production by MTG (Methanol to Gasoline) Process and Quality Adaptation
-Consideration of Gasoline Production through Comparison with FT Synthesis-

Kenichi Okamoto･Naoki Amitani･Noriyuki Aratani･Nobuo Oyama･Akio Imai･Seiya Suzuki･Noriaki Ohmori･Hiroshi Kisai (Japan Petroleum and Carbon Neutral Fuels Energy Center)

To address global warming and reduce greenhouse gas emissions, early introduction of bioethanol and synthetic gasoline for transportation fuels is strongly required. In this study, MTG (Methanol to Gasoline) synthesis was experimentally conducted, and the quality characteristics of the obtained MTG crude oil were analyzed to investigate approaches for complying with gasoline specifications through fuel property adaptation. In addition, production efficiency was compared with FT synthesis gasoline, and future directions for synthetic gasoline production and utilization were discussed from the viewpoints of fuel quality and manufacturing efficiency.

Comparison of Laminar Burning Velocities Between e-Fuels and Conventional Fuels

Dai Matsuda･Kei Kikuchi (Kyushu University)･Kenichi Okamoto･Nobuo Oyama (Japan Petroleum and Carbon Neutral Fuels Energy Center)･Ekenechukwu CHIJIOKE Okafor (Kyushu University)

To clarify the fundamental combustion characteristics of carbon-neutral fuels for application to spark-ignition engines, laminar burning velocities were measured using a constant-volume combustion vessel for commercial gasoline, MTG fuel, and a prototype FT synthetic fuel using synthetic gasoline obtained by JPEC through a NEDO-commissioned project. The equivalence ratio dependence was evaluated, and the effects of fuel composition and carbon structure on laminar burning velocity are discussed.

Engine Combustion Characteristics of Olefin-Rich Gasoline Derived from Fischer–Tropsch Synthesis

Kohei Kuzuoka･Mitsuharu Oguma (AIST)･Kenichi Okamoto (Japan Petroleum and Carbon Neutral Fuels Energy Center)

Fischer–Tropsch (FT) -derived fuels inherently face challenges in achieving sufficient anti-knock performance in gasoline engines. In this study, a surrogate fuel representing olefin-rich FT-derived fuel compositions was employed based on the assumption of an FT catalyst capable of directly producing olefin-rich fuels. Engine experiments clarified the influence of fuel composition on knock characteristics under various operating conditions. The findings provide insight into the relationship between olefin-rich fuel compositions and knock resistance behavior in gasoline engine operation.