Development and validation of a reduced combined biodiesel-diesel reaction mechanism

► A compact combined biodiesel-diesel reaction mechanism is proposed. ► The mechanism is able to emulate any diesel-biodiesel blends and feedstock type. ► Combination of mechanisms follows a chemical class-based approach. ► Reaction mechanisms of methyl crotonate and methyl butanoate are reduced. ► The mechanism accurately predicts the ignition delay timing under 234 conditions.