ENZYCLE: Microbial enzymes for treatment of non-recycled plastic fraction

Context

Plastic waste that is not reintroduced into the production cycle is a significant and increasing problem for the EU. In 2017, more than 27 million tonnes of plastic waste were produced in the EU28, the equivalent of more than 50 kg per citizen. However, less than one-third of this is recycled; the rest is either incinerated or sent to landfill.

Clearly, with the EU’s ambitions for a circular economy, and its stated strategy of achieving 100 % of plastic packaging as recyclable or reusable by 2030, this is challenging. It is therefore essential to find new advanced processes to recycle the fraction that is currently not recycled, particularly those plastics used for packaging –such as those PET based clamshells (polyethene terephthalate)– or those plastics found as microplastics.

Biotechnology is an evolving and dynamic industry which is playing important roles in economics, health, and the environment. New biotechnological processes are being developed to mitigate the effects of plastic pollution in sensitive environments by inserting plastics into the so-called circular economy where materials are valorised and reused after the end life of a product. These processes greatly benefit the environment and create business opportunities in the waste recovery sector.

Summary and objectives

The ENZYCLE project, funded by the Bio-based Industries Joint Undertaking (BBI JU) under the European Union’s Horizon 2020 program, will develop new processes to recycle enzymatically currently non-recyclable plastics such as PET trays and clamshells and PET/PE-PP multilayer packaging. For this reason, enzymes with a high hydrolytic activity on polyesters and on polyolefins will be identified and improved to establish efficient recycling processes. Additionally, ENZYCLE will deal with microplastics, developing a microplastic degrading system (MDS) capable of mitigating the negative impact on the environment and human health.

This ambitious 48-month project brings together 2 top research universities, 3 research centres, 3 innovative SMEs and 5 large industries which are currently developing revolutionary enzymatic processes with the ambition to solve worldwide end of life plastic issues. ENZYCLE´s experts will select a set of appropriate enzymes that have the potential to degrade non-recycled plastic fractions such as polyesters and polyolefins, and produce these enzymes in a very innovative and efficient process (continuous process) and validate them for the new recycling processes developed. The enzymatic treatment will deliver building blocks and polymers that could be reused in new products such as virgin PET, polyurethane foam, or polyols.

ENZYCLE will follow 4 phases, related to the different stages of development of the technology:

1. Identification and selection of novel enzymes
2. Production of these enzymes at pilot scale.
3. Development of an efficient enzymatic depolymerisation process to depolymerise the different plastic fractions such a as PET, PE and PP multilayer packaging, and microplastics.
4. Validation of the  enzymatic recycling processes at pilot scale and products obtained.

The new technologies and solutions will decrease the amount of non-biodegradable polymers sent to landfill. In addition, it will help deal with the issue of microplastics in wastewater by using the developed technology to degrade these contaminants. ENZYCLE is a chance for creating new markets, since the envisaged products and processes are applicable in packaging, transport, construction materials, textiles, etc. In addition, the project enlarges the range of feedstocks that can be effectively and sustainably processed through biocatalytic systems.

Consortium

A consortium of 13 partners from 6 European countries has been set up to reach the objectives abovementioned:

1.            INSTITUTO TECNOLÓGICO DEL EMBALAJE, TRANSPORTE Y LOGÍSTICA (Spain)

2.            UNIVERSITAET LEIPZIG (Germany)

3.            STICHTING WAGENINGEN RESEARCH (Netherlands)

4.            UNIVERSITAET FUER BODENKULTUR WIEN (Austria)

5.            ACIB GmbH (Austria)

6.            DARWIN BIOPROSPECTING EXCELLENCE SOCIEDAD LIMITADA (Spain)

7.            ASA SPEZIALENZYME GMBH (Germany)

8.            FEYECON DEVELOPMENT & IMPLEMENTATION BV (Netherlands)

9.            DEPURACION DE AGUAS DE MEDITERRANEO SL (Spain)

10.          SOPREMA (France)

11.          GREINER PACKAGING INTERNATIONAL GMBH (Austria)

12.          ALIPLAST SPA (Italy)

13.          Indorama Ventures Europe B.V. (Netherlands)

ITENE’s role

ENZYCLE project is organized in 10 work packages (WP), and ITENE is the Project Coordinator.

ITENE will work together with the project partners on identifying fossil-based polymer-degrading enzymes, especially for polyolefins. ITENE will also develop pre-treatment processes to optimise and improve the efficiency of the depolymerization process, especially regarding multilayer packaging . In addition, they will also contribute to the develop and validate the depolymerisation processes at a pilot scale.

ITENE will be involved in the development of new processes to face microplastic pollution in wastewater treatment plants by anaerobic digestion and by composting. ITENE will participate in the dissemination and transfer of knowledge of the results of the project and in the assessment of the sustainability under the perspective of Life Cycle Assessment of the new recycled materials. As coordinator, a part of our technical role, will maintain contact with the European Union Commission and will be responsible for monitoring the correct implementation of the project plan and taking appropriate measures to correct any deviations that may occur, as well as for the efficient financial management of the entire project.

Results

During the course of the project, a well-nurtured group of experts from different partner institutions, such as Darwin Bioprospecting Excellence, ITENE, the University of Leipzig (UL), Wageningen Research (WR); and BOKU have performed synergistic bioprospecting activities to discover, produce and characterise new enzymes from natural microorganisms that are present in soil, seawater and landfills, selecting those enzymes with the greatest potential to break down plastics into their original components (monomers), which can be used as building blocks to create new plastics.

The most promising enzymes, as well as the biological systems producing them, have been further engineered and improved for industrial use. Large-scale production processes of the selected enzymes has been possible thanks BOKU and ASA. This has allowed to develop and implement high-scale enzymatic depolymerisation processes of plastics, in a collaborative work between ITENE, WR and UL, together with INDORAMA and ALIPAST.

Subsequently, a downstream processing step has been developed to recover and purify the necessary monomers before they can be transformed into new plastics. To do this, FeyeCon applied supercritical CO2 technologies. Once the recovered building blocks had the necessary quality, they have been transformed into new materials, such as PET, by INDORAMA, to obtain new thermoformed PET materials by GREINER, and polyurethane foam, by SOPREMA. These new products are suitable for use in various sectors, including packaging, transport, construction and textiles.

Also, research done about recovering microplastics from waste water treatment plants and their degradation assessment has been possible thanks to the participation of DAM. Finally, ACIB has been highly active in the assessment of the economic feasibility of the developed processes, as well as in actions related to the dissemination and communication of the obtained results.