Successful Syngas Production from Plastic Based Pyrolysis Oil at the KIT High-Pressure Entrained Flow Gasifier

In the Carbon Cycle Lab at the Karlsruhe Institute of Technology (KIT), several institutes work together on a complete process chain for a sustainable carbon cycle. The aim is to convert residual and waste-based materials into high value chemical raw materials and thus replace fossil feedstock in the chemical industry. Following this approach, the Carbon Cycle Lab makes an important contribution to link the energy transition with the circular economy, supporting the transition to a resource-efficient, climate-neutral and competetive economy.

A central component of this innovative process chain is the high-pressure entrained-flow gasifier operated at the Institute for Technical Chemistry (ITC), see Fig. 1. The reactor converts pyrolysis oil into a high-quality syngas consisting of the main components hydrogen and carbon monoxide. So far, biogenic residues, e. g. straw, have been applied in projects like bioliq® and refuels, converting around 1,500 tons of biomass-derived pyrolysis products into syngas and fuel.

Supported by Air Liquide Global E&C Solutions Germany GmbH, the gasifier at ITC was adapted from the operation with oxygen-containing, residual biomass-based pyrolysis oils to the operation with almost oxygen free pyrolysis oils derived from plastic fractions with significantly higher energy content. With great interest from the industry and support from BASF, 20 tons of plastic-based pyrolysis oil were successfully applied in the high-pressure entrained-flow gasifier from 17 November to 7 December 2024. The feedstock was provided by ARCUS Greencycling Technologies operating a plant at Frankfurt Höchst, which is based on a process developed at the ITC.

Applying simulation and balancing models developed at ITC as well as experimental data from a smaller atmospheric gasifier (REGA) operated at ITC, optimal process parameters for a safe and efficient fuel conversion were determined in advance. An online balancing tool provided important characteristic numbers in real time during the tests and thus also enabled reliable operation at the limits of the process parameters.

Result: about 20,000 standard cubic meters of hydrogen and carbon monoxide, respectively, were produced from the plastic pyrolysis oil. The test campaign was an important step, as it demonstrated the successful production of syngas from mixed plastic fractions. Thus, the principle function of the process chain was successfully demonstrated. Future work will aim for a better understanding of the gasification process steps in order to reach a highly efficient operation with a wide range of feedstock specifications.

The successful completion of this campaign marked an important milestone in the research work funded by the Helmholtz Association in the MTET program (Materials and Technologies for the Energy Transition).