A study on cetane on demand technology part 1 - Development of fuel reformer to improve fuel ignitability-

The integration of low-octane gasoline with a compression ignition combustion system has been proposed as a strategy to reduce Well-to-Wheel CO2 emissions from automobiles in petroleum-based fuel. Also, gasoline components produced via Fischer-Tropsch (FT) synthesis exhibit low octane numbers, rendering them suitable for this combustion concept. In the current situation where low-octane gasoline is not widely available in the market, onboard reforming of commercial gasoline to increase the cetane number (lower the octane number) allows for compression ignition combustion even with commercial gasoline. This requires Cetane on Demand technology, which enables compression ignition combustion with both commercial gasoline and low-octane gasoline. It is known that the ignition property of fuel is enhanced when the fuel is oxidized to generate peroxides. Moreover, the use of N-hydroxyphthalimide (NHPI) as a catalyst promotes peroxide generation at low temperatures. The objective of this study is to develop a device that enhances the ignition properties of gasoline through onboard fuel reforming. Initially, from the NHPI-supported solid catalysts developed by the authors, a catalyst appropriate for a flow reactor operating at ambient pressure was selected. The NHPI-supported ZSM-5 catalyst demonstrated the highest performance in peroxide formation under flow reactor conditions. Subsequently, with a focus on onboard reforming, two types of reactors (spiral structure and inner-circulation structure) and two methods of air introduction (metal mesh bubbler and mechanical stirring bubbler) to ensure adequate contact between the fuel, air, and solid catalyst were designed and prototyped. The combination of the spiral structure reactor and mechanical stirring air introduction exhibited the best performance in peroxide formation.