OpenLOOP recycling technology - sustainable and profitable solution to the management of PET/cellulose waste

Project Information

OpenLOOP

Grant agreement ID: 190115848

DOI

10.3030/190115848

Project closed

EC signature date 9 December 2022

Start date 1 April 2023

End date 30 September 2025

Funded under

• The European Innovation Council (EIC)

Total cost

€ 3 500 045,00

EU contribution

€ 2 450 000,00

Coordinated by

IOS, INSTITUT ZA OKOLJEVARSTVO IN SENZORJE, PROIZVODNJA, TRGOVINA IN STORITVE DOO
Slovenia

Periodic Reporting for period 2 - OpenLOOP (OpenLOOP recycling technology - sustainable and profitable solution to the management of PET/cellulose waste)

Reporting period: 2024-04-01 to 2025-09-30

Summary of the context and overall objectives of the project

Europe faces rising amounts of mixed textile and plastic waste that current recycling systems cannot handle, especially blends of PET and cellulose. OpenLOOP addresses this gap with an integrated, circular technology that converts these complex waste streams into high-purity secondary raw materials.
The platform combines enzymatic hydrolysis to separate cellulose with neutral and alkaline chemical depolymerization of PET, producing high-purity rTA (~98%), 5-HMF (~99%), and LA (~98%). Residual cellulose is turned into pellets and insulation materials, more than 80% of water is recycled, and Life Cycle Assessments show major climate benefits. The project has optimized pre- and post-treatment, automated key steps, and developed specialized equipment, demonstrating strong industrial readiness across four coordinated work packages.
Market demand for high-quality, traceable non-fossil materials is growing, and OpenLOOP’s outputs meet or exceed industry requirements. The project aligns with major EU policy goals and has strong commercial uptake potential. A demonstration plant in Slovenia is being prepared to showcase the fully integrated recycling model.
In summary, OpenLOOP delivers a scalable, sustainable solution for turning mixed textile and plastic waste into valuable raw materials, supporting circularity, reducing emissions, and strengthening Europe’s transition to a low-impact circular economy.

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

The OpenLOOP project developed, scaled up, and validated processes for decolourising, depolymerising, and valorising cellulose, PET, PES, and their blends. WP1 defined technical requirements and product specifications, while WP3 ensured coordinated validation and technical risk control.
WP2 delivered the main scientific results. Decolourisation and depolymerisation processes were optimised at lab and pilot scale, improving parameters such as particle size, chemical dosage, and temperature. Enzymatic hydrolysis using new enzyme formulations and improved mixing achieved consistent glucose and rTA production. Additional methods, including supercritical CO2 and microwave-assisted treatments, expanded the process to more complex textile compositions.
Purification workflows produced high-purity outputs: rTA ≥98–99%, and 5-HMF and LA ≥98–99%. Specialised equipment ensured uniform processing, while solid residues were transformed into pellets and insulation foams. Enzymatic hydrolysates were also converted into terpenoids, such as limonene, demonstrating extended valorisation pathways.
Pilot-scale infrastructure was established, including pre-treatment, material handling, and wastewater systems combining nanofiltration and membrane bioreactors, achieving >80% water recovery. A Central Control System provided automated monitoring and control of all critical process parameters.
Final validation confirmed that rTA, 5-HMF, and LA met industrial purity requirements with reproducible yields, demonstrating the technical maturity and scalability of the OpenLOOP recycling platform.

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)

OpenLOOP has developed a fully integrated circular recycling platform that unites chemical PET depolymerisation, enzymatic cellulose hydrolysis, efficient water recovery, and custom-designed equipment into a scalable industrial process. The platform produces high-purity rTA, 5-HMF, and LA, all validated at lab and pilot scale with consistent quality and rTA production rates reaching 100 kg/day. Life Cycle Assessment confirms substantially lower environmental and climate impacts compared with conventional fossil-based routes. The project also achieved near-zero-waste operation by converting solid residues into pellets, insulation materials, and recycling more than 80% of process water. The development of dedicated reactors, filtration systems, and automated control modules further demonstrated strong industrial readiness.
These results offer significant environmental and economic benefits by diverting textile and plastic waste from landfills and incineration, reducing microplastic emissions, lowering greenhouse gas impacts, and supplying high-value secondary feedstocks for the chemical, textile, and packaging industries.
To ensure successful large-scale uptake, continued progress is needed in industrial-scale demonstration, investment, and market access for the first full-scale plant, and structured support for commercialisation and IP management. Broader engagement with European industry and alignment with EU regulatory and standardisation frameworks will be essential, alongside further research to optimise efficiency and support diverse waste streams.
Overall, OpenLOOP delivers a validated, scalable, and sustainable recycling solution with clear pathways toward industrial deployment and market adoption.

The insulation foam from residue after CELL enzymatic hydrolysis process

Efficient colour removal (PES yarn) significantly influence the end product quality (rTA).

Production of recycled terephatlic acid (rTA) from waste plastic, non-woven textile and waste textil

Enzymatic hydrolysis of waste cellulose textile to glucouse solution using new bioreactor

Repolymerization of recyc. terephatlic acid from waste texti. to recyc. polyethylene terephtalate