Organic residue masses are turned into energy

The organic residue masses created in agriculture, processing and bioenergy production have so far mostly been treated as pure waste materials, although there are great potentials for the energetic and economic use of these materials. These potentials need to be further explored and exploited, in particular given the challenges of climate change.

The aim of the German-Brazilian project TRABBIO is the development of methods and measures for the establishment of organic residue masses from sugar cane cultivation and utilisation as a sustainable and transferable biocoke product for different applications. The potential applications of this biocoke product are both in material use in the raw materials industry and in CO2-neutral substitution of energy sources. Among other things, TRABBIO is investigating the use of biocoke as an input material in the chemical raw materials industry for the production of polymers currently obtained by gasification of fossil petroleum coke. In addition, the project is investigating the biocoke recovery pathways as activated carbon or soil conditioners.

As part of TRABBIO, biogenic energy sources are to be obtained as convertible goods as well as conditioned for further applications. In general, such a procedure has already been tested and established for input materials, for example. The innovation of TRABBIO, however, is the holistic research and development of the accruing organic residues masses from sugar cane harvests and the subsequent refinement and stabilisation as a convertible product. There are no stable holistic procedures for this at this point. The developments of the individual steps in the process chain are risky and require further research.

Development of holistic procedures

With current harvesting techniques, soil particles such as sand or ferrous soils get into the processes along the entire harvesting, processing and recycling chain. This causes a significant reduction in the quality of the organic residue raw material and increased wear of all machines. Therefore, another of TRABBIO's main subjects of study is the overall harvesting technique as well as the collection and resource-efficient use of sugar cane leaves and tips remaining in the fields. On the one hand, these organic residues masses prevent soil drying and ensure natural fertilisation of the soil. On the other hand, however, organic residue masses lying on the ground prevents the sugar cane plants from budding and growing again. This leads to crop damage. The project aims to develop innovative and complete or partial harvest concepts that are adapted to the respective region which prevent soil drying on the one hand, and do not lead to crop failures on the other hand. The aim is to prevent the contamination of the residual masses and to develop a concept for preconditioning. Various parameters are being examined and adjusted to ensure maximum output for subsequent coking of the residual masses.

Detailed knowledge of material flows along the value chain is indispensable for the development of integrated sustainable technologies. This also includes integrated land management including yield management for both the sugar / ethanol products and the organic residue mass. In addition, harvesting and processing techniques as well as logistics and cooperation models adapted to the emerging biocoke material flow must be considered and developed for a holistic approach. On the one hand, this helps to optimise resource efficiency and, on the other, to protect the ecosystem by minimising negative effects.

Sustainability meets economy

The process development in the research project should include a scale-up with industrial trials to make it possible to apply the concepts to industrial use. As a result, a significant reduction of climate-damaging gas emissions, the first-time utilisation of previously unused biogenic material flows as well as the optimised use of organic residue masses by means of temporal and spatial decoupling of accrual and use by producing a convertible and storable, stable material with high substance and energy density are being pursued. TRABBIO is not only making an important contribution to exploiting the great potential of organic residue masses, but is also offering approaches for the development of new, sustainable value chains in the agriculture and raw materials industry. This combination of economy and ecology is gaining in importance against the background of climate change and its consequences.