A Study on Cetane on Demand Technology Part 2: Gasoline Reforming and Ignitability Evaluation

<div class="section abstract"><div class="htmlview paragraph">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. However low-octane gasoline is not widely available in the market currently. Onboard reforming of commercial gasoline to increase the cetane number (lower the octane number) allows for compression ignition combustion even with commercial gasoline.</div><div class="htmlview paragraph">To reform commercial gasoline, a reformer with a spiral structure reactor and mechanical stirring air introduction was designed and prototyped based on the results of toluene reforming tests (A Study on Cetane on Demand Technology Part 1: Development of fuel reformer to improve fuel ignitability). Using N-hydroxyphthalimide (NHPI)-supported ZSM-5 as a catalyst, commercial gasoline was reformed. As a result, 25.5 liters of reformed gasoline was obtained. The hydroperoxide concentration in the entirety of our reformulated gasoline was determined to be 1.5 mmol/L, based on the hydroperoxide concentration measured at each sampling site and the corresponding volume collected.</div><div class="htmlview paragraph">The ignitability of the reformed gasoline was evaluated using an internal combustion engine. Under premixed homogeneous conditions, no difference in ignitability was observed between the gasoline before reforming and the reformed gasoline. However, under non-uniform/diffusion combustion conditions, it was confirmed that the ignitability of the reformed gasoline improved compared to the gasoline before reforming. For the factor analysis, a chemical reaction calculation was conducted, and it was found to be due to the concentration of OH derived from the reformed gasoline. Under diffusion combustion (diesel-like) conditions, the evaluation of engine combustion showed that reformed gasoline expands the lean limit and improves combustion stability in the low-load operating range.</div></div>