The Re-injection Loop concept:Economically efficient biogas production from manure fibres and straw

There is a huge unexploited biogas potential from manure and agricultural residues in Europe and worldwide. However, these substrates consist of alarge fraction of fibres (range 5-80% of dry matter content) with a low methane potential and represent a marginal economy due to their low biogasyield per ton. Based on previous studies on using pretreatment for enhancing the biogas yield of these feedstocks, a new concept called Re-InjectionLoop was developed by combining separation and recirculation of the digested fiber fraction with pretreatment of the recalcitrant lignocellulosic fiberfraction. The EU project BIOMAN is currently investigating different technologies for separation, mechanical pretreatment and enzymatic hydrolysis toestablish an economically viable concept for manure-based biogas plants