SUSTAINABLE WAYS OF DRYING GRAINS: THREE CONCEPTS

The use of renewable energy has rapidly gained acceptance in many industries worldwide, not only for electricity generation but for thermal applications as well. In the food industry and many other agricultural applications, renewable energy is utilized in aiding the drying processes of food products such as grai ns. This paper focuses on sustainable ways of drying grains using biomass energy and solar energy technologies. The aim of the research study was to investigate drying methods that rely on green energy solutions in order to optimize the drying of grain. The research conducted identified three conceptual designs that were found to be economically viable for the design and construction of sustainable grain dryer systems using biomass energy and solar energy for heat generation. As discussed in this paper, concept 1 uses an air-to-air heat exchanger to transfer the heat generated by the biomass burner in order to initiate the drying process. Concept 2 uses the same principles as those of concept 1 but the heat from the biomass burner is transferred through a combination of an air-to-water heat exchanger and a radiator. Due to the abundant production of corn and sugar cane in South Africa, corn stovers and sugar cane waste are seen as potential sources of biomass energy for these concept designs. Concept 3 relies on the use of solar energy. In this concept, a forced convection multilayer solar dryer system is assisted by an electric heater which is powered through a solar panel system. This allows an electric heater to be used during off-peak sunshine hours such as when it is cloudy or at nighttime.