Valorization of Agricultural Wastes and Biorefineries: A Way of Heading to Circular Economy

Abstract

In a circular economy, one tries to encompass closed loops between different value chains introducing changes in the production and consumption patterns. Design for the environment, extended producer responsibility, critical consumption, cleaner production, biomimicry, degrowth, etc. are some of the strategies that will help to foster a circular economy. Industrial symbiosis is another effective strategy to achieve such a goal. Agro-industrial wastes provide an enormous potential to generate sustainable products and bioenergy. An integrated biorefinery is turning into a promising solution with multiple outputs (biofuel, bioactive compounds, and biomaterials). In this paper a couple of biorefineries are described as a way to contribute to circular economy: a biorefinery based in seeds and vegetable wastes and a biorefinery based in a cactus' fruit, Opuntia Joconostle. Also, the possible valorizations of different agricultural wastes in Mexican systems and the symbiotic systems are described. The combination of several of these synergies in the same system will lead to an industrial symbiosis system. The use of these symbiotic systems on a large scale could give a significant contribution towards a circular economy in the agricultural sector. Most of the valorizations described have been tested or proposed by the authors in real examples in Spain and Mexico. Barriers and lessons learned in the implementation of both biorefinery and symbiotic systems are discussed.