Circular economy and secondary raw materials

The circular economy and secondary raw materials working group is concerned with strategies, concepts and processes for the extraction of secondary raw materials that can be returned to the economic cycle in a high-quality manner. In addition to the conceptual development of waste management concepts, the focus is on the development of new processes for the material and energetic utilization of waste or its constituents.

Key aspects

  • Waste management concepts
  • Treatment processes of biogenic waste
  • Urban Mining

Current research projects on the bioeconomy are investigating the material use of biogenic waste from households, agriculture and industry. The objectives are new biorefinery concepts for obtaining biobased products. The research work is partly carried out in cooperation with developing and newly industrializing countries and includes, in addition to the development of waste management concepts, the transfer of teaching. A major goal of urban mining is the recycling of high-value material flows. In this context, we are working in cooperation with the IWKS on the development of sorting techniques for the recovery of high-quality plastics.

Skills

Information about the composition of various types of waste can be gathered by using sorting experiments. These data are crucial for the development of reutilization and waste management concepts.

Space for the experiments is available in an experimental hall of the TU Darmstadt. Here the wastes can be delivered, sorted, and characterized. Wastes are mostly either residual, biological. or recyclable. The sorted types of waste can be further analyzed using physical, chemical, and biological tests according to the LAGA PN 98 guidelines using the laboratory equipment of the IWAR Institute. These sorting experiments are combined with on-site inspections of refuse container locations, observations of sorting behavior, and the development of strategies to overcome deficits.

The chair of Material Flow Management and Resource Economy offers a range of technical-analytical equipment for these sorting experiments, most importantly:

  • Sorting tables
  • Sorting containers
  • Scales
  • Sieves in various sizes
  • Drum sieves/screens (manually adjustable)

Additional equipment for sample preparation and crushing can be used in cooperation with other chairs at the TU Darmstadt.

The development of new processes in the chair of Material Flow Management and Resource Economy is focused on material recycling and the recovery of the energy and materials contained in wastes. Included in this are improvements in separation, collection, and concentration or extraction of the waste fractions and the materials contained therein. Technical development work is done using the workshop and the laboratory capacities of IWAR. It is possible to characterize the experimental yields and efficiencies of waste treatment processes with the help of input-output substrate analyses. Various types of equipment can be constructed in the IWAR workshop to demonstrate the effects of different process set-ups. It is thus possible to vary process parameters and to determine optimal operating conditions. The Material Flow Management and Resource Economy chair also operates test facilities on partner premises, as for instance at the composting plant of EAD of the city of Darmstadt.

Based on many years of experience ranging from the gathering and recording waste materials to its biological, mechanical and thermal treatment to its disposal, the chair of Material Flow Management and Resource Economy has acquired profound expertise in developing waste management plans.

When developing sustainable waste management plans, we take into consideration the prospective waste quantities, the logistics, and process technology. Specifically, the chair can work on the following tasks:

  • Analysis of the current and future quantities of waste
  • Determination of the relevant waste parameters, e.g., breathability and the formation of gases
  • Development of plant design concepts for waste treatment
  • Educational courses and training sessions to improve waste management
  • Identification of areas for optimizing waste management planning that takes into account municipal and operational boundary conditions.