A chemical protocol for the evaluation of potential biogas production from biologically pre-treated agro-industrial wastes

To date, the types of pre-treatment of agro-industrial wastes use mostly physical and chemical (alkaline hydrolysis, acid hydrolysis, oxidative de-lignification and solvent extraction) methods, which have drawbacks both from the environmental point of view and the energy consumption. In this scenario, BIT4enERgy, an entrepreneurial idea supported by SPINNER2013, has developed an innovative biological pre-treatments based on selected strains of microrganisms capable to decompose the biomass recalcitrant (hemicellulose, lignin - Figure) aimed to biogas production in anaerobic digestion. BIT4enERgy, in partnership with Biotec sys srl, is promoting new concept of integration between feedstock biological pre-treatment and advanced anaerobic digestion processes able to convert efficiently agro-industrial wastes with the conversion of high amount of CO2 for biogas production without additional climate change gas emission, supporting a transition towards a low-carbon economy [1,2]. In the present study we show the results on chemical-physical features of agro-industrial wastes before and after biological pre-treatment by using elemental, thermal (TG-DSC) and spectroscopic (ATR/FT-IR) analyses. Particular attention was paid to lignin structural changes as a consequence of biological pre-treatment. Chemical data suggested that the biological pre-treatment allowed a reduction in mass of biomasses in shorter time, the energetic power of the biomasses rich in lignin was increased, the efficiency of their conversion in bio-methane was improved and finally a considerable reductions of greenhouse gas (GHG) balance was expected.