PyroVC – adding value from previously non-recyclable polyvinyl chloride waste
Funding source: EFRE – LeitmarktAgentur.NRW / funding code EFRE-0802070
Polyvinyl chloride (PVC) is a thermoplastic material that has become indispensable in many products of daily life. Due to its advantageous properties, its applications in industry (construction and electronics) are enormous. PVC is the third most consumed plastic in the world, with 37.4 million tons per year, behind polyethylene and polypropylene.Although PVC was the most produced plastic in the world as early as 1945, the recycling issue has not been sufficiently addressed. The recycling rate in Germany is 37%, which is lower than the average recycling rate for plastics, which is 46%. The usual approaches to PVC recycling (landfilling and incineration) are either energy-intensive or inefficient in terms of reuse quality or environmentally harmful due to the release of harmful gases.
Pyrolysis technology makes it possible to break down PVC in the absence of oxygen and recover petrochemically usable plastics from it. Pyrolysis is the thermal decomposition of chemical compounds at high temperatures (600 °C) and breaks down the long-chain molecules into organic compounds. However, pyrolysis releases chlorine gases, which can be separated, for example, by bonding with sodium in the preliminary stage of the pyrolysis process. This leads to further useful products such as salts and enables pyrolysis without the formation of harmful waste gases. However, the successful establishment of pyrolysis technology on a large scale faces economic and operational difficulties due to fluctuating waste volumes and types and high capital investment. Rising energy and electricity costs and increasing disposal fees are currently creating new opportunities for small-scale recycling plants. Challenges are the robustness of the pyrolysis technology and the adaptation of fluctuating waste quantities and types, the automatic plant control to reduce the manpower and thus the costs.
Within the scope of the project, AES is developing a new plant technology that makes it possible to process waste containing chlorine into a pyrolysis oil and hydrochloric acid or common salt. AES is responsible for the design and construction of the chlorine separation and the associated pyrolysis technology. In cooperation with the University of Applied Sciences Aachen the economic efficiency is already considered during the project. Finally, the new plant technology will be tested at a pilot customer. Through this technical innovation of the automated pyrolysis plant with ecological consideration, C-cycle closure, CO2 savings, elimination of non-recyclable waste streams and efficient use of material resources and recycling can be achieved.