Achieving Net Zero Greenhouse Gas Emission Plastics

Since the early 1950s, synthetic plastics have been used in almost all areas of life, including transportation, buildings, packaging, and even healthcare. As a result, plastic consumption has increased twenty-fold between 1964 and 2014, from 15 to 311 million tons per year. However, as a result, plastic pollution has become a serious problem besides global oil consumption and greenhouse gas (GHG) emissions.

Raoul Meys from the Chair of Technical Thermodynamics and Professor André Bardow, Chair of Energy and Process Systems Engineering at ETH Zurich, have now shown in a study that by combining recycling, biomass utilization, and carbon capture and utilization (CCU), net zero GHG emissions from plastics can be achieved. The study, recently published in the academic journal Science, is based on a new holistic model of global plastic production and disposal.

The term net zero means achieving a balance between the carbon emitted into the atmosphere and the carbon removed from it, so the carbon footprint is zero. Strategies to reduce GHG emissions include decarbonizing the energy supply in the plastics supply chain and replacing fossil carbon inputs with closed-loop technologies such as chemical and mechanical recycling, biomass utilization, and carbon capture and utilization. To achieve net-zero emissions, all three closed-loop technologies must be utilized.

When optimally combined, the energy demand of a circular industry may be up to 53 percent lower compared to that of a fossil-based industry with extensive carbon capture and storage (CCS).

In addition, operational costs for net-zero emission plastics are comarable to those for linear fossil-based production with carbon capture and storage and, under beneficial conditions, could even be substantially reduced. 

Although the lower energy requirement may seem striking at first, it can be explained by energy savings over the entire life cycle and by recycling: Fossil-, bio-, and CO2-based pathways can only recover the energy contained in plastics during waste incineration, which inevitably leads to inefficiencies – as a result, energy is lost. In contrast, recycling preserves the energy content of plastics through reuse, reducing net energy demand.

However, to realize maximum cost savings, biomass and CO₂ must be available at low cost, oil extraction and supply must be made more expensive, and investment incentives for recycling must be put in place.

The authors show that the use of policy instruments to increase the availability of plastic waste as a resource and to provide economic incentives for increased investment in biomass and CO2 utilization can promote the path to net-zero emission plastics. 

Thus the circular economy could transform production systems to achieve net-zero emissions plastics with lower energy requirements and operating costs by decoupling them from fossil carbon resources, improving economic and environmental well-being alike.

Contact

Raoul Meys
Phone: +49 241 80 90477
E-Mail: raoul.meys@ltt.rwth-aachen.de

Source

RWTH Aachen, press release, 2021-10-01.

Supplier

Rheinisch-Westfälische Technische Hochschule Aachen (RWTH)

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