<p>The effect of thermal and electrohydrolysis pretreatment on methane yield from lignocellulosic pulp and paper mill sludge was studied in batch assay at mesophilic (37 ± 2°C) conditions. Both pretreatments showed an enhanced methane production rates and shortened the lag phase, with thermal and electrohydrolysis methods yielding increases of 33.73% and 39.20%, respectively. Electrohydrolysis also demonstrated superior energy recovery, achieving a net energy gain of 12,259&#xa0;kJ which was 57% higher than the 7,040&#xa0;kJ obtained from thermal pretreatment. In addition, three kinetic model were evaluated. All the models fit the experimental data with greater R²&gt; 0.970. The modified Gompertz model showed the best fit in both pretreatment with greater R²&gt; 0.998. Improved methane production couples with high net energy gain and reduced retention time could make the electrohydrolysis pretreatment more attractive for future installation of the full-scale industrial anaerobic reactor level.</p>