Mathematical model of thermal processes in a biogas plant Amur Fiapshev, Olesya Kilchukova, Yuriy Shekikhachev, Marat Khamokov and Luan Khazhmetov MATEC Web Conf., 212 (2018) 01032 Published online: 15 October 2018 DOI: 10.1051/matecconf/201821201032