BW2Pro

Organic waste is a versatile and future-proof source material for the conversion of residual materials into raw materials. Its versatility enables, but also requires, a diverse approach for the complete utilization of all components. The BW2Pro project aims to develop a versatile utilization network.

Funding period:

October 2021 – October 2024

Reference number:

Bioök_2275052

Four secondary raw materials are to be produced in the BW2Pro project: Fibers, cellulases, polyhydroxyalkanoates (PHA) and biogas. In addition, two finished products will be manufactured: biodegradable plant pots and fertilizer. The concept envisages the recycling of a large proportion of the residual materials generated in the process. The biorefinery will be located on the site of the Rems-Murr waste management company's biowaste fermentation plant in Backnang-Neuschöntal.

The biorefinery concept to be developed provides for thermal pressure hydrolysis as pre-treatment for municipal biowaste. All of the components of the split biowaste are separated into liquid process water and solid fiber fractions. The medium fiber lengths can be pressed directly into a product, in this case plant pots. Shorter fibers are used for the production of cellulases, enzymes that are used in detergents, for example.

The process water from thermal pressure hydrolysis, which mainly contains organic acids, is used for several purposes. Firstly, it is fermented into biogas in a two-stage fermentation system. This produces fermentation residue as a by-product, which is upgraded to complex fertilizer and ammonium fertilizer, or components thereof, through nutrient recovery. In addition, the process water is used as a starting material for polyhydroxyalkanoates, the PHAs. This biodegradable plastic alternative is created by various microorganisms as a carbon store and offers a broad property profile for a variety of applications. Production is to be demonstrated on a laboratory scale using project substrates. In addition, a production process is to be scaled up to pilot scale. The sample quantities produced will be tested by project partners for their marketability and further processed.

The modular structure of the biorefinery is suitable for the separate use of the developed processes and technologies in other biowaste recycling contexts and makes it possible to upgrade existing biogas plants.