The general objective of the BIOGREEN project was the development of a green biorefinery for the treatment of surplus agricultural waste and the generation of energy and bioproducts within agro-industrial environments. This objective pursued several goals: to contribute to the advancement toward a circular and decarbonized economy, the development of endogenous technologies, and the integration of waste management with the generation of energy and products with high added value in agro-industrial environments.
With these aims, a process was outlined involving raw material specifications, subprocesses, and their integration and optimization as a whole; the optimization of a raw-material conditioning subprocess through the development of a pilot press system; and finally, the pilot assembly of a biorefinery model (hydrolytic digester + anaerobic digester), with subsequent validation at industrial scale.
The project was articulated through 6 modules, GalChimia being the leader of module 3 (Production of added-value compounds from the fiber fraction). The objectives related to each activity are detailed below.
Activity 1 – Raw material fractionation: Evaluation of the fractionation and processing of the raw material (green biomass) into its two main constituents: press-juice and press-cake.
Activity 2 – Anaerobic digestion process in two phases: Study of the two-phase anaerobic digestion of the press-juice obtained from biomass fractionation. Optimization of the process yields, maximizing the production of volatile fatty acids (VFAs) and biogas.
Activity 3 – Production of added-value compounds from the fiber fraction: Development and optimization of a process for the production of cellulose acetate from the green biomass press-cake. Evaluation of different lines of use of the biomass, based on chemical and/or enzymatic processes. Synthesis of membranes from the obtained cellulose acetate for separation applications.
Activity 4 – Development of the production process of polyhydroxyalkanoates (PHAs) in mixed culture. Study of the PHA production yield in mixed culture by feeding with the VFAs from the hydrolytic reactor. Construction and automation of a pilot system for PHA production. Development of a polymer recovery process at laboratory scale.
Activity 5 – Study of the use of digested material as fertilizer.
Activity 6 – Integration, modeling, and optimization of the process. Environmental and economic analyses. Definition and analysis of feasibility and business plan.
The BIOGREEN project has successfully met the established objectives by achieving the following results:
Two-phase pilot plant of the BIOGREEN project.
GalChimia thanks all the members and collaborators of the project BIOGREEN for their involvement and work, which have been key to obtaining the present results.
The project has been carried out in collaboration with the companies Norvento, Agroamb Prodalt, Syspro, and Idener, and the technological centers AINIA and CETIM. It has been funded by the Center for the Development of Industrial Technology (CDTI), the European Regional Development Fund (ERDF), and supported by the Spanish Ministry of Economy and Competitiveness.