Microbial ENZYmes for treatment of non-recyCLEd plastic fractions

Project Information

ENZYCLE

Grant agreement ID: 887913

DOI

10.3030/887913

Project closed

EC signature date 30 April 2020

Start date 1 June 2020

End date 31 May 2024

Funded under

• SOCIETAL CHALLENGES - Food security, sustainable agriculture and forestry, marine, maritime and inland water research, and the bioeconomy

Total cost

€ 6 078 222,50

EU contribution

€ 4 445 880,00

Coordinated by

INSTITUTO TECNOLOGICO DEL EMBALAJE, TRANSPORTE Y LOGISTICA
Spain

Periodic Reporting for period 3 - ENZYCLE (Microbial ENZYmes for treatment of non-recyCLEd plastic fractions)

Reporting period: 2023-06-01 to 2024-05-31

Summary of the context and overall objectives of the project

Plastic waste management has become a challenge for our planet. Mankind produces 27.1 million tonnes of plastic waste every year and only 31.1% can be recycled. Over 65% is landfilled or incinerated. This huge amount of waste is associated with CO2 emissions of 6.7 million tonnes per year. The Enzycle project, funded by the Bio-based Industries Joint Undertaking (BBI JU) under the European Union's Horizon 2020 programme, offers a solution to these figures: the project has looked for new processes to treat and recycle plastic fractions that cannot be recycled today. It focuses on multi-layer packaging, post-consumer polyethylene terephthalate (PET) trays, clamshells and microplastics in wastewater. The aim of the project is therefore to reduce the amount of plastic that ends up discared in landfills or in the oceans.

The combined efforts have led to the discovery, production and characterisation of new enzymes from natural microorganisms found in soil, seawater and landfill. These enzymes have demonstrated their potential to break down plastics into their original monomers. The most promising enzymes and the biological systems that produce them have been further improved for industrial use. In parallel, robust processes for depolymerising the different plastic fractions at pilot scale have been developed. Sophisticated approaches based on green supercritical technology were then used to recover and purify the monomers prior to their conversion into new plastics. Studies on the quality of the monomers and the properties of the plastics produced from them provide guidance on their use. At the end of the project, polyurethane (PU) foams, polyethylene (PE) films and repolymerised PET suitable for thermoforming applications were successfully produced.The techno-economic analysis carried out shows that the enzymatic recycling technology is feasible, although optimisation (of both the enzyme production and the recycling process) is still required to achieve commercial viability. Targeting premium applications, such as sportswear, could provide an immediate market for the recycled terephthalic acid. A notable outcome of this project is the development of BioProcessNexus software, a freely available tool that allows stakeholders to calculate economic and environmental metrics to facilitate informed decision making in process engineering.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In WP1 and WP2, the enzymes to be used in the recycling processes were identified. In WP3, scale-up strategies for enzyme production were defined and optimised in both E. coli and P. pastoris, both with good results in terms of expression level and activity of the enzymes produced, thus reducing environmental impact and economic costs. WP4 has developed pretreatments capable of inducing oxidation in polyolefin fractions and reducing crystallinity in PET fractions, as well as enzymatic depolymerisation technologies for monolayer PET, multilayer materials and microplastics (TRL3-4). WP5 has made progress in the identification and quantification of microplastics in wastewater streams, designed a pilot plant for the separation of these microplastics and evaluated the biodegradation processes using bacterial isolates obtained in WP1 and recombinant enzymes developed in WP2 and WP3 for the development of a microplastics degradation system. The evaluation of microplastic degradation supported by enzymatic treatments in composting and anaerobic digestion processes was also carried out. The validation of the depolymerisation technologies at pilot scale and the production of new materials (proof-of-concept prototypes: trays and yoghurt pots from repolymerised PET, production of PU foams with partial replacement of phthalic acid by recovered terephthalic acid (TPA) and mechanically recycled PE films from the non-degraded fraction of PET-PE) were the objectives of WP6. In WP7, environmental and economic assessments of the development processes were carried out with the aim of developing processes that are both environmentally sustainable and industrially competitive.In WP8, an intensive positioning and dissemination of ENZYCLE was carried out in all the sectors involved in its value chain, where, together with WP9, a network of synergies with other European projects are being created.

Comprehensive strategies were put in place to streamline IP processes to ensure they are in line with industry best practice, covering key aspects such as confidential know-how, publications and patentability options. A patent application has been filed for the purification and crystallisation process of TPA: P100947NL00 (30.05.2024).The highlights of D&C activities have been :
- Social media community reached 930 followers.
- 2 scientific papers published in 2023, 8 manuscript in preparation for peer-reviewed publications.
- 32 poster and oral presentations at conferences.
- Discussion workshop/ roundtables with 2 school classes about plastic recycling, bio-based plastics and biodegradation (European Researchers Night “Life is Science”).
- ENZYCLE webinar together with sister projects (BIZENTE and RECOVER) “The potential of enzymatic plastic recycling”.
- Final event (9th to 10th April 2024, Madrid).
ENZYCLE continued to release regular newsletters, to publish articles at the “News” section of the website (25 articles) and to distribute the ENZYCLE card game at open events.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

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. A number of microbial strains and genes with potential for biodegradation of polyolefins have been identified, isolated and tested in synergy with oxidative treatments as a solution to increase the degradation rates of these polymers of fossil origin.
Technologies have also been developed to enable more cost-effective production of enzymes, as well as new processes for the depolymerisation of PET containers and multilayers of polyesters and polyolefins, and for the treatment of microplastics in wastewater streams.
This project has deepened the scientific and technical understanding and explored new industrial sectors for enzyme applications by creating new sectoral linkages. ENZYCLE technologies will promote the creation of new value chains between the biotechnology sector and the chemical and waste management sectors, which will have a positive impact on the creation of new jobs, transforming traditional low-skilled jobs into high-skilled jobs.
The environmental impact will be reduced by reducing greenhouse gas emissions and energy consumption. The landfill of non-recycled fractions will be reduced as Enzycle processes represent a new paradigm in the treatment of complex waste fractions. Such processes are also positioned as safer technologies. In the case of enzymatically recycled (er) TPA compared to virgin (v) TPA, more than a 50% reduction in GHG emissions per kg of PET was shown to be possible. For erPE compared to v low-density PE (LDPE), the reduction in GHG emissions is around 35% per kg of PE obtained. Considering that the processes still have room for optimisation, these are very promising results. Considering a plant treating 50,000 Mt of PET trays/year, which is the scale used for the techno-economic assessment, almost 14,000 Mt CO2 eq would be saved compared to the baseline scenario (30% landfill + 70% incineration).

Enzycle Project General flow diagram