An investigational study was accomplished to establish the burning process, performance, and emission parameters for the Homogenous Charge Compression Ignition (HCCI) diesel engine while using Ethyl Alcohol as an additive to increase the available oxygen for combustion in diesel-biodiesel blends. The combustion characteristics were examined numerically by applying the multi-zone chemical kinetics model. In which three sorts of zones enclosing the crevice zone, boundary layer zone, and center zone of the engine cylinder are activated. The multizone code was joined with a new complete chemical kinetics mechanism that contains 144 species and 737 elementary reactions. The whole HCCI engine combustion and emission characteristics were studded at different volume of biodiesel and ethanol of D70B25E5, D70B20E10, and D70B15E15. The simulation results were validated by the in-cylinder real pressure history and the obtained results were judged against an HCCI engine fueled with pure diesel fuel. The exploratory and predictions outcomes exposed that D70B15E15 blend provides higher brake thermal efficiency; simultaneously reducing the flue gas temperature when the ethanol percentage were increased into the tested blends. The lower values of Carbon Monoxide, Oxides of nitrogen, Smoke opacity were detected with the blend of D70B15E15 and were 42.10%, 9.09% and 53.64% respectively which war quite inferior to that of conventional diesel fuel. On the other hand, The Carbon dioxide and Hydrocarbon emissions were slightly increased with the increase in the percentage of ethanol in diesel-biodiesel blends than that of diesel fuel.