Optimized use of biogenic waste streams through the combined production of bio-based products and bio-hydrogen

Since 2015, there has been a legal obligation in Germany for the districts and cities to collect biowastes separately, which are then treated in a composting plant or fermentation plant. However, in both aerobic and anaerobic biowaste treatment, a large part of the carbon contained in the waste is released in the form of carbon dioxide (CO2) without using the raw material potential it contains. Against the background of efforts to save climate-relevant gases and the scarcity of natural resources, the aim of biological waste treatment should be to make better use of the potential of bio-waste through innovations in the known treatment processes. These innovative processes should make better use of the carbon contained in the biomass and obtain higher-quality and economically profitable bio-based products from it, to substitute primary raw materials. In a first step, the anaerobic process of dark fermentation initially produced short-chain carboxylic acids from organic waste streams. This process also produces a hydrogen-containing biogas that can be used for energy. In a secondary fermentation, the carboxylic acids are then to be lengthened and separated using a non-polar extractant. The extended carboxylic acids then serve as platform chemicals for the manufacture of various bio-based products.