VALPLAST Project Aims to Convert Plastic Waste into Biogas

(Bioenergy Insight) VALPLAST - a strategic project consisting of a consortium of members, and funded by the European Union - will aim to recover biodegradable plastic waste through anaerobic co-digestion treatment with sludge from sewage treatment plants (STP).

This will obtain a biogas stream that can be used as an energy vector and a digestate for agriculture.

The VALPLAST consortium includes AIMPLAS, the Plastics Technology Centre, the CALAGUA Group UPV-UV Mixed Unit (made up of the Research Institute of Water and Environmental Engineering at the Universitat Politècnica de València and the Department of Chemical Engineering at the Universitat de València), and the companies Global Omnium Medioambiente and Fych Technologies.

The project, financed by the Valencian Institute of Competitiveness and Innovation (IVACE+i) within the framework of the European Union’s 2023 strategic cooperation projects, seeks to implement an alternative to current management of biodegradable plastic packaging waste that is aligned with circular economy principles.

“The main innovation of the project involves understanding that bioplastics are a resource that can be recovered and transformed into green energy,” according to researchers participating in the project.

The aim will therefore be to study, at laboratory and pilot scale, the degradation of different plastics through biological treatment with sludge from municipal sewage treatment plants under anaerobic conditions.

The possible effects of the additives used in the synthesis of plastics (conventional and bioplastics) in the anaerobic treatment process and the subsequent quality of the digested sludge will also be evaluated, given that its main application is agricultural use.

Work will also be done on the development and optimisation of pilot plant instrumentation and control systems, as well as the analysis of costs and the life cycle.

As consortium members highlighted: “They are essential to be able to evaluate the environmental and economic sustainability of the proposed treatment.”

After the recovery process, analysis will be carried out to measure the presence of microplastics in the sludge.

For this analysis, the methodology developed by AIMPLAS in previous projects (MICROPLAST and PREVENPLAST) will be used.

This method makes it possible to measure these emerging contaminants in both wastewater and the sludge generated at treatment plants.

The process will be used to develop a methodology for energy recovery from bioplastics at STP digesters for better management of these wastes resulting in greater energy recovery. READ MORE

Excerpt from European Bioplastics: Certified compostable products support the separate collection of municipal biowaste, a practice essential for high-quality organic recycling, which includes both industrial composting and anaerobic digestion. By offering consumers an easy solution to separate their household biowaste, they increase the volume and quality of valuable compost that is generated via industrial composting. In case the waste is processed via anaerobic digestion, a larger amount of separately collected biowaste can additionally help to increase the share of biogas production.

A range of Anaerobic Digestion technologies and configurations exist throughout Europe, which are biomass-specific. Municipal biowaste usually consists of a mixture of organic kitchen waste and (garden/yard) green waste. Given that the ligneous part of green waste is difficult to convert to biogas in anaerobic digestion, combinations of an anaerobic and aerobic steps are deemed most suitable for processing municipal biowaste. Via this combination, the maximum value is retrieved from biowaste: biogas as a source of energy, and compost as a fertiliser or soil-improver.