Utilization of sweet sorghum as a catch crop for producing raw materials to be used for production of bioethanol and biogas

The increase of the annual demand for renewable raw materials or resources as well as the fuel vs. food discussion require that new production channels are found for the needed raw materials and resources. Catch crops for producing renewable materials and resources as well as cascading use has been the subject of various research projects at the laboratory level but have never been part of large-scale experiments under Central European realistic conditions. With sorghum (sorghum bicolor), agricultural areas in Austria have access to a catch crop plant that can be used in a cascading manner. Parts of the plant can be used as raw material for the Bioethanol industry and the remainder of the plant to produce second-generation biogas utilizing thermo-mechanical pulping methods. The opportunity of being able to use a large part of the raw materials required from plant residues as well as generating a raw material to produce Bioethanol are the motivation for operators of biogas plants. This will make a new raw material available to the Bioethanol industry, which is then able to sever the connection to grain and corn price fluctuations. From an economic point of view, a lesser demand for grains or corn for the Bioethanol industry as well as to produce biogas means more areas under cultivation can be used to produce food. The goal of the project is to use the complete production cycle to show that the production of raw materials for the Bioethanol industry and second-generation biogas production with catch crops (sorghum bicolor) can be realized in a sustainable, ecological, and economic manner. This evidence is provided with the use of large-scale plant studies and under the guidance of scientists and in cooperation with farmers, biogas plant operators and Bioethanol producers to determine the potential sorghum type as well as the optimal harvesting and storage methods and the most efficient method for making the raw material available to the Bioethanol industry and the biogas plant. This is achieved with a combination of laboratory works and technical monitoring, which extends across the entire production cycle. Individual components available in the industry are adapted in such a way for the raw material production of the Bioethanol industry as well as the preparation of the residual plant mass from the catch crop for the production of biogas that these are suitable for the large-scale study in the form of a pilot plant to determine, based on the technical monitoring, which technical process adaptation tasks between existing biogas plants and the additional system components are required to yield a plant configuration, which enables, for the most part, a stable production cycle (the investment of the pilot plant is not part of the project but is made available for this project). This is to result in a handbook consisting of two parts prepared with the aspect of sustainability, ecology, and efficiency in mind. The first part provides information about what plant cultivation options, harvesting methods, logistics chains, and storage possibilities of the raw material are available for the raw material production. The second part describes the technical prerequisites required to realize the cascading use of the catch crop sorghum bicolor.