Biogas potential of residues generated by the tomato processing industry under different substrate and inoculum conditions

Methane production from tomato waste is a complex, multi-step process that involves multiple syntrophic interactions, and, because of its high lignin and cellulose content, the waste is difficult to degrade. To test the suitability of tomato plant degradation for methane production, biomethane potential (BMP) tests were carried out considering different total solids (TS) content (0.5-7.0%, w/v) and substrate presentation (dry and fresh). Tomato plant degradation achieved up to 150-240 L CH4 kg-1 volatile solids (VS), considering 1.0-3.0% TS content, in which the humidity content of the substrate did not affect the methanation process significantly under the proposed conditions. Further pretreatments need to be considered in order to improve methane production and generate more energy from each planted hectare.