The Re-iinjection 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 a
large fraction of fibres (range 5-80% of dry matter content) with a low methane potential and represent a marginal economy due to their low biogas
yield per ton. Based on previous studies on using pretreatment for enhancing the biogas yield of these feedstocks, a new concept called Re-Injection
Loop was developed by combining separation and recirculation of the digested fiber fraction with pretreatment of the recalcitrant lignocellulosic fiber
fraction. The EU project BIOMAN is currently investigating different technologies for separation, mechanical pretreatment and enzymatic hydrolysis to
establish an economically viable concept for manure-based biogas plants.