Nov-2024

Defining a robust plastics recycling pathway (ERTC 2024)

The rising demand for plastics presents two main challenges: the environmental impact of production and waste and the reliance on fossil resources.

Cecile Plain and Nicolas Menet
Axens

Article Summary

Enhancing plastic waste management through reducing, reusing, and recycling is crucial. Recycling plastics reduces the need for fossil resources and maximises waste utilisation. Most recycled plastics come from mechanical recycling, with limitations such as requiring homogeneous waste and not removing additives, leading to material degradation. Axens and IFP Energies nouvelles (IFPEN) have been developing advanced recycling processes to eliminate additives and impurities, achieving quality comparable to virgin materials. Several of these technologies are now available and leveraged in the planning and development of chemical recycling projects.

The plastic industry, and notably petrochemical companies, when considering the implementation of a chemical recycling unit in their plant, are confronted with several options that need sorting and clarifying (such as integration into existing plant, capacity, staged investment, feedstock sourcing, integration of the waste feedstock preparation unit, balance between feedstock preparation, and severity of operation). At this crucial stage, decisions made on shallow bases and guesswork can lead to many delays and cost overruns during project execution and operation. Axens, through its consulting department Axens Horizon, is proposing upfront studies that bring a global and coherent approach to the evaluation process of a plastics chemical recycling project.

For example, Axens’ consulting group recently conducted a comprehensive feasibility study for a refinery in Western Europe. The refinery aimed to identify the optimal processing configuration to chemically recycle post-consumer plastic waste using its existing infrastructure. Additionally, the refinery sought to partially replace fossil feedstock and reduce its overall CO₂ footprint. In just a few weeks, that study enabled the establishment of a complete screening of the options and, through a financial analysis of the different cases, the definition of a robust pathway for getting the refinery to play a role in the plastic’s circular economy.

The study was articulated in two main phases: screening and development of the selected configuration.

Screening
During the screening phase, eight different processing configurations were compared to determine the most efficient and effective approach. This included, but was not limited to:
· Construction of a grassroots pyrolysis plant, leveraging Axens’ expertise in that field as the co-licensor with Plastic Energy of the proven and robust TAC technology.
· Processing of the pyrolysis oil in existing refinery assets to produce petrochemical feedstock or petrochemical intermediates. Evaluating co-processing in various units, such as the FCC, involved assessing the impacts on existing units, including feedstock composition and impurities. Additionally, the evaluation included product yield assessment and process scheme optimisation.
· Revamp of an existing hydrotreatment unit into a dedicated purification unit, leveraging Axens’ Rewind Mix technology expertise.

The initial technical-economic ranking of the different solutions enabled clients to select the configuration that was then further developed.

Technical development
This phase involved detailed technical assessment development, including material balance, utilities, and off-site requirements.
· Economic development: Economic aspects were addressed, including Capex and Opex.
· Financial and sensitivity analysis: A thorough financial analysis was conducted, along with sensitivity analysis, to understand the economic viability under different scenarios. Crucial variables impacting potential profitability were identified.
· Environmental impact: This was evaluated considering preliminary life cycle assessment for each pathway to quantify potential CO₂ reduction.

In some other studies for petrochemical and refinery companies, the study scope was further enlarged to include screening the different options to produce plastics intermediates from renewable feedstock. Economics and preliminary life cycle analysis were used in the process to rank the different bio and circular pathways for the given site studied.

Each of the cases is, of course, highly subject to the evolution of the legislative framework, which is still under definition for several elements. Together with the site owner, Axens experts ensure that the plan is robust enough to accommodate  possible changes in legislation implementation. In each of these study cases, Axens Horizon delivered to site stakeholders a long-term planning document that guides the future growth and development of the  site.

This short article originally appeared in the 2024 ERTC Newspaper, which you can VIEW HERE