Effect of Substrate Characteristics and Process Fluid Percolation on Dry Anaerobic Digestion Processes

Abstract

The dry anaerobic batch digestion process is an organic waste treatment technology most appropriate for the treatment of stackable (non‐free‐flowing) dry organic waste materials. The effect of the process fluid percolation and substrate permeability on methane production of organic household waste was investigated in anaerobic dry digestion trials at pilot scale. The container system consisted of two percolation digesters and a fixed‐bed methane digester. The experimental results indicate that material compaction occurs during the digestion process and can have a negative effect on substrate permeability. Structure material addition reduced material compaction and as a result increased the substrate permeability.

High-Solid Anaerobic Digestion: Reviewing Strategies for Increasing Reactor Performance

“…The recirculation of leachate or a liquid phase, rich in anaerobic microflora, is a common practice to allow for the redistribution of soluble compounds and microorganisms. However, as degradation and solubilization of the organic material take place, compaction of the organic bed may be experienced if not enough structuring agent is introduced when initially loading the reactor [51]. The purpose behind adding a structuring agent is to create a porous media to favor liquid circulation and prevent the formation of preferential pathways, which may lead to localized acidification in inner reactor zones.…”