Project objectives -The principal objective of BIOMAN is to develop a new treatment concept "the Re-Injection Loop" for anaerobic digestion plants where energy production is based on manure and 2nd generation energy biomass (straw, agricultural waste, aquatic waste). The innovative new treatment loop will increase the biogas production significantly and improve the overall economy of biogas production.

The new concept for biogas plants will consist of solid-liquid separation, followed by superior mechanical and enzymatic treatments with expected synergy effect when applied on pre-digested and dewatered biomass. The treatments are developed specifically for pre-digested biomass with high levels of lignocellulose and they will be applied on the pre-digested fibre fraction only. This will result in low-cost treatments designed specifically as part of the Re-Injection Loop as combinations of mechanical, enzymatic and biological treatments directed at the recalcitrant fibrous fraction. The result will be a longer retention time for the fibrous fraction, which after treatment will consist of opened fibres convertible for methane-producing bacteria.

The whole Re-Injection Loop concept will be developed for small and medium-sized biogas plants and demonstrated on a farm, where biogas production has recently been implemented. However, the Re-Injection Loop concept can easily be upscaled for larger (cooperative) biogas plants and for operation on other mixtures of biomasses including energy crops.