A strategic complement
Some plastic waste streams may be difficult or unsuitable to process through conventional mechanical recycling because of contamination, mixed composition, material degradation, technical limitations or economic considerations. Depending on local collection and waste-management systems, these streams may otherwise be sent to disposal or energy-recovery routes.
Chemical recycling comprises several process routes that use chemical, thermal or catalytic methods to transform selected plastic waste streams. Depending on the technology and polymer type, these routes may recover monomers, chemical intermediates, purified polymers or synthesis-gas components.
Depending on the waste stream and process route, chemical recycling may complement mechanical recycling by processing selected plastics that are difficult to handle through conventional mechanical methods. Some routes can produce recovered chemical intermediates, monomers or other feedstocks for use in subsequent manufacturing processes.
Why GEA?
Depending on the feedstock and selected process route, plastic-waste composition may range from relatively uniform fractions to highly heterogeneous mixtures. A typical process configuration may include chemical conversion or depolymerisation, gas conditioning, and upgrading or purification, although the individual steps depend on the technology and application.
GEA evaporation, crystallization, distillation and drying technologies can support selected separation, purification and recovery steps in plastic-waste processes. Our emission-control technologies address relevant gas streams, including pyrolysis gas and exhaust air, as part of the applicable treatment configuration.
- GEA evaporation technologies can support the concentration of spent liquors containing dissolved chemicals, the removal of volatile components from polymer solutions, and the separation or recovery of solvents used in selected dissolution-based recycling processes. These steps may contribute to polymer purification, depending on the process configuration.
- GEA distillation technologies can support the separation and purification of selected liquid products from pyrolysis processes and the recovery of certain monomers from depolymerisation streams. Depending on the gas-treatment configuration, complementary separation technologies may also be used to condition or purify components such as H₂, CO, CO₂ and CH₄.
- Where suitable to the process chemistry, crystallization can support the separation and purification of selected monomers from depolymerisation streams, the recovery of certain additives or impurities, and the isolation of specific compounds from complex chemical-recycling mixtures.
- GEA drying technologies can support moisture removal from selected plastic-waste feedstocks before processing and the drying of recovered polymers after solvent-based purification or precipitation steps.
- GEA emission-control experts address gas-conditioning requirements beyond cooling, including the treatment and preparation of relevant gas streams for subsequent process or upgrading steps, where applicable.
Our engineers combine process-engineering experience with a range of separation, purification, drying and emission-control technologies to develop process configurations tailored to specific customer requirements. The resulting energy use and emissions profile depend on the selected technology, feedstock, process design and operating conditions.
Our on-demand Webinars
Watch our Expert Talks for insights into GEA’s ongoing work in process technology. Explore topics such as process optimisation, energy use, emissions-related challenges and sustainability considerations in specific industrial applications.
