The model of high solid anaerobic digestion was used by improving the degree of homogeneity of the reaction system and biogas slurry reflux to gradually increase the material load. The vinegar residue-efficient anaerobic digestion system was successfully constructed without pretreatment.The optimum anaerobic digestibility was observed when the material loading of the reaction system reached 6.15 g·(L·d)-1, when the amount of biogas produced per unit of dry material was 396 mL·g-1, and the amount of methane produced per unit of dry material was 211 mL·g-1. The degradation rate of hemicellulose reached 63.66%, which was the main reason for the improvement of anaerobic digestion performance. The degradation rates of cellulose and lignin were 21.46% and 24.43%, respectively. The lower degradation efficiency was mainly due to the complicated degradation of the benzene ring structure in lignin and hindered hydrolysis of cellulose, which had a shielding effect on cellulose degradation.
Keywords: anaerobic digestion; cellulase; lignocellulose; material loading; vinegar residue.