The Project

The Wastes-to-Biopolymers project aims to develop environmentally friendly and economically feasible bioconversion processes of food industry wastes into bioplastic products. Emphasis is placed on the utilization of liquid waste streams, derived from the production of dairy products (cheese whey) and from fruit and vegetable juicing (sugar fractions), for the synthesis of completely biodegradable polymers (polyhydroxyalkanoates, PHAs), with applications in food packaging.

According to the waste management hierarchy, the reuse of wastes as raw materials for the production of new products is the most favored option after their prevention or minimization. Consequently, mild and environmentally friendly processes, such as biochemical and biological conversion processes, are the most suitable options for their prioritization at the top of the pyramid.

The Project - A37EE460

Methodology

The main objective of the methodology followed the by project focus on the sustainable production of short- and medium-chain length PHAs (scl-PHAs and mcl-PHAs, homopolymers and copolymers) with tailored properties, from substrates derived from the pretreatment of selected wastes. The biopolymers are formulated into food packaging products (plastic bottles, cups, films, etc.), completing the circular approach of the proposed technology. In addition, in the context of the zero-waste circular economy, the simultaneous exploitation of all available components of the raw materials is performed via the co-production of biohydrogen.

More specifically, the individual objectives of the project can be summarized as follows:

The characterization and pretreatment of the available liquid waste fractions,derived from the food industry, through standard and innovative methods (e.g., enzymatic processes): minimization of the demands for refining wastes, towards the preparation of fermentable nutrients media for PHAs and H₂ production.

The optimization of biocatalysts (bacteria and enzymes) for wastes pretreatment processes and for the production and recovery of biopolymers. Emphasis is placed on selecting the most efficient microorganisms to optimize pure and mixed fermentation processes, depending on the type of PHAs that can be produced (scl- and mcl-PHAs).

The optimization and upscale of fermentation processes to produce PHAs: cost minimization and production rate maximization.

The control of the molecular weight and, in general, of the properties of the produced biopolymers, based on the operational conditions of the cultivation and recovery processes.

The development of innovative methods for separating PHAs from the bacterial biomass (e.g., enzymatic processes): low cost and minimal energy and environmental footprint.

The control of end-product properties according to the targeted food packaging applications: formulation and evaluation of bioplastics in real applications.

The mathematical simulation of the different production stages in order to intensify their performance.

The techno-economic assessment and life-cycle analysis (LCA) of the complete value chain, targeting to an integrated sustainability analysis.