News Release (August 31st 2015)

The main objective of ReWobioRef is to explore the techno-economic feasibility, scientific requirements, and material specifications to utilise recycled waste wood in lignocellulosic (LC) biorefinery processes as an alternative feedstock source.

The secondary aim is to valorise the recycled waste wood components (cellulose, hemicelluloses and lignin) for more sustainable biobased fuels, chemicals and materials.

The ReWoBioRef project addresses only recycled waste wood that has already gone through one utilisation stream and therefore is considered as secondary raw material having reached the end-of-waste criteria according to the EC waste directive. Recycled waste wood material from eleven different sources in Germany, Slovenia, Finland, and the UK has been collected and analysed. The results show that chips of recycled wood A I had higher concentrations of inorganic pollutants than softwood chips, and also some pieces of non-wood material.

Preliminary results on steam explosion and ethanol based organosolv cooking without an acid catalyst showed typical softwood behavior for A I quality recycled wood in respect of hydrolysability, thus being potential future raw material for sugar production. The recycled wood was processable unmilled, and milling pre-treatment was not necessary prior to steam explosion in a batch reactor.

A IV recycling wood lots have been tested with favorable results in the Enerkem process that converts mixed organic wastes and residues into a pure synthesis gas (or syngas) which is suitable for the production of biofuels and chemicals using proven, well-established and commercially available catalysts. The economic model described in the literature for a lignocellulosic biorefinery with organosolv-pre-treatment of beech wood chips for the production of lignin has been adapted in this paper to varying ratios of A I recycling wood as alternative feedstock. Mainly because of the high operating costs, the relatively low income for the considered output products and lignin revenues around of 600 €/t (2015), the scale effect for the organosolv-pre-treatment currently classifies it as not economically viable when 100% beech wood chips are used as feedstock. The uncertainty in revenues, especially for the by-products glucose and xylose, is the major reason. However, if A I recycling wood is used, the economics improve significantly since lignin can be produced with profits of between 180 and 270 €/t. These assumptions are based on the data sets used for the referenced model calculation basically by varying the feedstock mix input. The major financial risk factors thus remain with the reference model but are significantly reduced.