Hydrogen production from an on-board reformer for a natural gas engine: A thermodynamics study

•Marine NG engine with REGR technology assists to improve in-cylinder combustion and emission performance.•The thermodynamic model of exhaust gas-fuel reforming process is established and demonstrated by experimental data.•The equilibrium composition of reforming products can be regarded as reference standard for practical product concentration.•The optimal area of high reforming characteristics and ηRE for exhaust reformer operation is acquired.