The suitability of biomass value chains from feedstocks via processes to products were evaluated. The work included biomass selection, procurement and characterization, process tests and modelling at lab and pilot scale and product quality tests. The biomasses were selected based on availability in Europe and diversity in terms of species and climate: “wet” biomasses (grape pomace, corn stover, corn leaves, coffee cake, brewery and greenhouse residues) suitable only for hydrothermal processes, and “dry” biomasses (Scots pine bark and forest residue, beech chips, poplar, willow, reed canary grass, wheat straw, sunflower shells, grape seed cake and corn cob) suitable for a wider range of processing. It was found that for all technologies, the process conditions need to be optimized separately for the various raw materials in order to reach optimal product properties.
Work by SPC and SLU on pelletizing of a wide variety of non-treated and torrefied materials has led at SLU to development of an innovative instant in-die steam conditioning device for improved process control and flexibility, which has been benchmarked with the pelletization tool of RAGT. Animal bedding was identified as a potential end use for the pellets. Biogold’s original target was hydrothermal pretreatment for saccharification. However, their process was found to be more feasible for biogas production. The present technology, in a somewhat bigger scale, will potentially be a realistic approach for commercialisation. ETIA constructed a new type of torrefaction unit with integrated drying and torrefaction, feasible for mobile application. Torrrefaction is a suitable technology for various solid side streams. CEA helped to create better understanding on the torrefaction process using various processing equipment and conditions. Raussi constructed a mobile unit for the production of biochar from dry, solid biomasses. The main product is biochar, but with the novel technical solution that Raussi has patented, also potentially valuable liquid fractions can be collected separately. VTT’s bench-scale tests gave information about the yields of biochar, liquid and gas. VTT studied the potential of hydrothermal carbonization (HTC) in laboratory scale, especially for the treatment of wet biomass residues. This process was not demonstrated as a mobile unit. Wet oxidation tests on HTC liquid fractions were performed at RISE Processum together with VTT to explore how their environmental impacts can be minimized. Detailed studies on chemical and physical activations of biochar were performed, benchmarking HTC and slow pyrolysis biochars.
In order to evaluate the value of the products obtained by the mobile processes, CHIMAR produced particleboard type panels from raw biomasses, products and by-products from these processes aiming at replacing the presently used wood or improving the properties of the panels. Typical pellets and biochars proved unsuitable materials for particleboards but panels with torrefied products showed improved thickness swelling which makes them suitable for applications where panels of high resistance to moisture are required and low mechanical properties are acceptable.
Luke characterized the biochars and tested them as soil improving materials and the liquid fractions as biopesticides and for manure acidification. These results emphasize the importance of end-product characterization as well as the need for detailed studies for each specific end-use purpose. A common roadmap was defined with Luke for characterization of biochar and liquid produced in the mobile slow pyrolysis unit.
LCA studies were carried out by VTT (slow pyrolysis & HTC), RISE (pelletizing), and FCBA (torrefaction). The product systems were subdivided into a set of unit processes, with respective material and energy flows. Potential business cases were evaluated by the lead of RISE, taking into account all relevant policy aspects, legislation and funding opportunities.
In addition to ordinary dissemination tools and activities, four Demonstration Technical Meetings including field visits and two open seminars were organized in Umeå (Sweden), Paris region (France), Southern Finland and Estonia. A Summer School on characterization and pretreatments was organized in conjunction with the 6th WasteEng Conference in Albi (France). Third Open Seminar was organized conjointly with the WasteEng ─7th International Conference, in Prague, Czech Republic, July, 2018. 19 presentations were given.
