Bridging Thermochemical and Biochemical Conversion: Impact of Biochar Addition on the Anaerobic Digestion of Aqueous Pyrolysis Condensate
Abstract
Profitable treatment of low value waste biomass is one of the biggest challenges of the industry. Where most of the current treatment strategies, such as pyrolysis, are efficient in complete breakdown of hard to synthesize, low value waste biomass such as lignocellulosic wastes, it leads to the generation of secondary waste thereby compromising its efficiency. The aim of this research is to utilize the aqueous pyrolysis condensate as a feedstock for anaerobic digestion, previously adapting the microbial consortia to the acidity and other potential organic inhibitors present in the APC, to produce energy in the form of biogas following the path of circular economy. Adaptation was an effective strategy in increasing the tolerance of the consortia to higher APC concentrations. The use of biochar reduced total phenolic content by 80% thereby allowing the consortia to utilise, more efficiently, higher concentrations of the substrate, and improved biogas ratios by 88.8%. Higher biochar:APC ratios created a more favourable environment for the bacterial growth and propagation.