Biorefinery for fertilizers for on-farm consumption in fruit and vegetable farms.

BioREFINA is developing a new circular model through an on-site production system for three types of fertilizers derived from its own waste biomass.

Biorefineries are facilities capable of converting biomass into bioenergy and/or bioproducts in a sustainable manner. The goal of the bioREFINA project is to transform, on-site, the plant waste generated on fruit and vegetable farms—such as crop residues, size-related or quality-related rejects, and other organic waste—into three high-quality biofertilizer products. In this way, a fruit and vegetable farm would transition from purchasing fertilizers from third parties to producing its own biofertilizers made from its plant waste—or from waste in its immediate surroundings—under a circular economy model.

Biorefinery processes begin with thermophilic anaerobic digestion, which stabilizes the organic matter and reduces the risk of microbiological contamination. The biogas produced is used as a renewable heat source to provide energy self-sufficiency for the subsequent processes that transform the digested material into fertilizers.

The solid fraction of the digested material is transformed through composting with other co-substrates into a functional organic soil amendment to improve soil quality and crop health; the water and nutrients (primarily nitrogen, phosphorus, and potassium) present in the liquid digestate are used as a liquid fertilizer in Fertigation systems; in addition, a portion of the liquid digestate is used to cultivate microalgae and subsequently produce a microalgae-based biofertilizer rich in amino acids and plant hormones.

Fertilizers produced using the bioREFINA system stand out for their high hygiene standards and low carbon footprint—essential characteristics for fruits and vegetables sold in markets in central and northern Europe, where standards in this area are particularly stringent.

The success of the bioREFINA R&D&I project lies in its full alignment with new agricultural sustainability policies based on bioeconomy models, by implementing a circular economy process at the agro-industrial farm level that, among other things, helps reduce the use of mineral fertilizers, improves energy management on farms, boosts fruit and vegetable productivity, and establishes a proprietary waste management and recovery system.