SOLAR DRYING AS AN ALTERNATIVE FOR THE THERMAL TREATMENT OF AGRO-INDUSTRIAL WASTE

Abstract

Science and technology have demonstrated that it is possible to minimize the environmental impacts of solid waste generation and, at the same time, increase the supply of energy from renewable sources through the use of agro-industrial residues as biomass. Brazil is one of the countries with the greatest prospects in the world for utilizing agro-industrial residues for bioenergy, given its extensive agricultural activity. This residue, on the other hand, requires drying to be standardized and stabilized under appropriate conditions for thermochemical conversion processes to be economically and energetically viable. Thus, a significant reduction in waste moisture can be seen as an interesting alternative for the treatment and use of materials that would otherwise be improperly discarded and can now be seen as energy sources. However, drying is known to be an energy-intensive operation, and therefore, alternative, more energy-efficient, low-cost techniques have been the focus of study by several researchers, particularly when it comes to the use of solar energy. Drying using solar energy is an interesting way to diversify the country's energy matrix, as it uses free, clean, and renewable energy. It is worth noting that Brazil has great potential for generating photovoltaic solar energy, which motivates the use of solar dryers. This chapter presents a brief review of the literature on the thermal treatment of agro-industrial waste using solar energy, given that the use of alternative energy sources to a conventional drying system is of great scientific and technological relevance. The chapter concludes that the use of solar dryers for the thermal treatment of this waste may be very promising; however, studies in this vast area of research are still lacking, particularly regarding scaling up and reducing drying time.

DOI: 10.56238/edimpacto2025.051-004