Ingo Ball: SMIBIO Case Study in Germany - Green Biorefineries in the Bavarian Region of Straubing-Bogen
The next presentation, given by Ingo Ball, who is a project manager in the bioenergy department at WIP Renewable Energies, was about the SMIBIO case study of a green biorefinery in Bavaria.
First Mr Ball showed how a green biorefinery (GBR) is classified within the classification system of IEA Bioenergy Task 42. In general a green biorefinery processes fresh wet biomass, such as grass, clover, alfalfa or immature cereals. First processing of wet biomass involves dewatering (e.g. screw press) to obtain two separate intermediates, a nutrient-rich juice organic solutions (press juice) and a fibre-rich lignocellulosic press cake. Both intermediates are starting points for various valorization pathways.
The organic solution (press juice) contains valuable compounds, such as carbohydrates, proteins, free amino acids, organic acids, minerals, hormones and enzymes depending on the used feedstock (fresh biomass or silage). Silage juice has already been demonstrated as feedstock for bio-chemicals and fuels production. Lactic acid and its derivatives as well as proteins, amino acids, bioethanol and energy via AD are the most favorable end-products.
The press cake fibres can be used as green feed pellets, processed to fibre products (e.g. insulation material) or used as raw material for other platforms (e.g. C6 and C5, syngas and lignin).
The concept of a green biorefinery makes it a product driven biorefinery.
The planned GBR in Germany shall be located next to an existing biogas plant, close to the city Straubing (Bavaria, Germany). The GBR shall be as integrated as possible into existing processes (logistics as well as demand for products). An amount of 15,550 t/year of grass and grass-like garden waste is available for free in the region and would mean a cost-saving base for the total feedstock (aim of 30,000 t/year). In order to scale up the feedstock amount grass silage can be purchased from farmers nearby. Mr Ball then gave a technical overview of the technical concept of the planned plant which includes nanofiltration and chromatography as energy-demanding components. To generate the needed energy in a sustainable way is one of the challenges of this concept. The products to be obtained of the GBR are lactic acid, amino acids and bioenergy (out of the press cake). Several aspects still need to get clarified in this case, among them are the validation of data taken out of literature, searching for energy supply alternatives for the process, identification of cooperation partners and the performance of a LCA.
At the end of the presentation an example of an existing mobile biorefinery (from the Dutch company Grassa) was shown which said that after investment costs of 60 EUR/t for grass silage it’s possible to gain 700-800 EUR/t for the separated components of the grass (including fibres, protein/amino acids, polysaccharides, mono/di-saccharides, organic acids, lipids).
Mr Ball concluded his presentation pointing on the abundance of the feedstock grass in many places, allowing development especially in rural regions. If the existing challenges can be overcome then GBR will be an interesting possibility for the local communities worldwide.