The Impact of Thermochemical Exhaust Energy Recovery Using Ethanol-Gasoline Blend on Gasoline Direct Injection Engine Performance

Thermochemical exhaust energy recovery in a modern gasoline direct injection engine is investigated using ethanol-gasoline blend (E25) and gasoline, as base fuel. The primary objectives of this research are focused on reducing carbonaceous emissions as well as improving thermal efficiency and fuel economy in combustion engines. These are consistent with the global commitment to lessen carbon emissions and meet environmental regulations and agreements. The possibility of hydrogen production through catalytic reforming of mentioned fuels using actual exhaust composition is investigated on full-scale Rh (Rhodium)-Pt (Platinum) catalysts. ANSYS-Chemkin is utilized for thermodynamic equilibrium analyses based on the Gibbs energy minimization method to explore the key reaction pathways for E25 reforming. Main reforming parameters including steam to carbon molar ratios and reforming temperatures are selected to investigate the feasibility of ethanol-gasoline blend reforming as well as to identify the reformate composition and evaluate the whole process efficiency. The results revealed that the presence of ethanol in reforming fuel mixture facilitates endothermic reactions and improves hydrogen-rich mixture, particularly at high engine load conditions where maximum heat recovery is obtained. Furthermore, E25 fuel reforming helped achieving up to 16% greater CO2 compared to gasoline fuel reforming under the same engine condition. Overall, the experimental results of full-scale reforming tests using E25 can be accredited for effective implementation of the reforming technique in practical application.