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Microbial ENZYmes for treatment of non-recyCLEd plastic fractions

Periodic Reporting for period 1 - ENZYCLE (Microbial ENZYmes for treatment of non-recyCLEd plastic fractions)

Reporting period: 2020-06-01 to 2021-11-30

Plastic waste that is not reintroduced into the production cycle is one of the main environmental and economic problems facing the European Union. More than 27 million tonnes of plastic waste were produced in the EU28 and only 31.1 % can be recycled. About two-third of plastic waste is landfilled or incinerated. These huge amounts of waste come along with a CO2 emission of 6.7 million tons per year. Regarding the economic impact: the management of plastic waste causes costs of more than 19.3 billion Euros per year.
The European Union has taken a global initiative to make 100% of plastic packaging recyclable, reusable or compostable by 2030, thereby moving towards a circular economy model. It is therefore essential to find new recycling processes for the fraction of plastic packaging that is currently not recycled, in particular PET trays and clamshells, PET/PE and PET/PP multilayers or microplastics.
Biotechnology is a highly dynamic and constantly evolving area of biology that is playing an important role in economics, health and the environment. New biotechnological processes are being developed to include plastics in the circular economy, enabling their reuse and recovery at the end of their useful life. These processes greatly benefit the environment and create new business opportunities in the sector.
The ENZYCLE project, funded by the Bio-based Industries Joint Undertaking (BBI JU) under the EU's Horizon 2020 program, will develop new processes to enzymatically recycle plastics that are currently not recyclable, such as PET trays and multilayer PET/PE-PP packaging. For this reason, enzymes with high hydrolytic activity in polyesters and polyolefins will be identified and improved in order to establish efficient recycling processes. In addition, ENZYCLE will develop a system for the degradation of microplastics, thus mitigating their impact on the environment and human health.
ENZYCLE will select and develop a set of enzymes that have the potential to degrade non-recyclable plastic fractions such as polyesters and polyolefins. These enzymes will be produced in continuous production, and will be validated in the new recycling processes developed within the ENZYCLE framework. The enzymatic treatment will provide monomers and polymers that could be reused to produce new materials such as virgin PET, polyurethane and other polyols.

The enzymatic treatment will follow 4 phases, related to the different stages of technology development:

Identification and selection of new enzymes.
Production of these enzymes on a pilot scale.
Development of an efficient enzymatic depolymerisation process to depolymerise different plastic fractions such as PET, PE and PP, multilayer packaging and microplastics.
Validation of the enzymatic recycling processes at pilot scale and of the products obtained.
New technologies and solutions will reduce the amount of non-biodegradable polymers sent to landfill. In addition, it will help solve the problem of microplastics in wastewater by using the technology developed to degrade these pollutants. ENZYCLE will show a new opportunity to create new markets, as the envisaged products and processes are applicable in packaging, transport, building materials or the textile industry. In addition, the project expands the range of raw materials that can be efficiently and sustainably processed by biocatalytic systems.
During these first 18 months, the first phase of the project has been developed, where the bases for the development of technologies and processes for the treatment of the plastic fractions object of this study have been established.
Within WP1 and WP2, the selection of microorganisms and potential enzymes to be applied to the recycling processes has taken place. In WP3, production strategies have been defined in both E. coli and P. pastoris, both with promising results both in terms of expression level and activity of the enzymes produced, so that the expression system is dedicated in terms of environmental impact and economic cost.
Within WP4, pre-treatments capable of inducing oxidation in polyolefin fractions and decreasing chrysotile in PET fractions have been developed. As well as the initial definition of recycling processes at laboratory scale (TRL3-4).
WP5 has advanced in the identification of the microplastics present in the wastewater streams, a pilot plant has been designed for the separation of these microplastics and the evaluation of the biodegradation processes using the wild strains developed within WP1 and WP2 in the composting and anaerobic digestion processes has been started.
Within WP7, the basis for environmental and economic evaluations of the development processes has been established, with the aim of developing processes that are environmentally sustainable as well as industrially competitive.
Within WP8, an intense positioning and dissemination exercise of ENZYCLE has been carried out in all the sectors involved in its value chain, where, together with WP9, a network of synergies with other European projects has been created.
To date, this project has been a milestone in the development of biotechnological tools for implementation in the recycling of fossil-based polymers that cannot be recycled today.
In this sense, during these first 18 months, potential microorganisms have been identified and isolated for the treatment of polyolefins, in particular polyethylene and polypropylene, where synergies with certain oxidative treatments are making it possible to increase the degradation rates of these polymers of fossil origin and also to increase the efficiency of the enzymatic depolymerization of polyesters such as PET.
Technologies are also being developed to enable more cost-effective enzyme production, as well as the development of new processes for the depolymerization of PET containers and multilayers composed of polyesters and polyolefins, and the treatment of microplastics in wastewater streams.
This project will deepen the scientific and technical understanding of these developments, as well as explore new industrial sectors for enzyme applications by creating new sectoral interconnections. In addition, it will foster the creation of new value chains between the biotechnology sector and the chemical and waste management sector.
It will boost the creation of new jobs and even transform traditional low-skilled jobs into high-skilled jobs.
In environmental terms, the environmental impact will be reduced by reducing GHGs and energy consumption. In addition, landfilling of non-recycled fractions will be avoided, as the processes proposed by Enzycle will represent a new paradigm in the treatment of complex waste fractions. Likewise, these types of processes are positioned as safer technologies.
Enzycle Project General flow diagram