Waste biomass in Turkey and solar drying as a new alternative for its utilization as feed

Abstract

Sources of waste biomass in Turkey were classified in this study. The amounts belonging to the items of the classification were estimated. The current use of these wastes were discussed and it was suggested that the best way to recycle nutritious wastes was using them as feed. Since some of these wastes are high in moisture, it is essential to protect them against bacterial spoilage by drying. Drying, on the other hand, is an energy intensive process. The economical feasibility as well as the ecological benefit of drying wastes by burning fuels is questionable. An economical solution at least for countries with abundant solar insolation would be the use of solar energy for drying. Various methods of solar drying of food wastes were examined. Open air as well as forced air drying gave bacteriologically inadequate products. Therefore, solar boiler dryers, working at 105°C, were constructed. To prevent the observed temperatures higher than 105°C at the later stages, drying was conducted in two stages. While sterilization and removal of most of the water were achieved by boiling in the solar boiler dryer at the first day, open air drying at the second day allowed to obtain a light brown colored product with trace amounts of bacteria and mold. The energy efficiency for vaporization was 85%. Heat losses of the whole dryer due to reflection, convection, and radiation were calculated to be 13%, 7%, and 20%, respectively. Suitability of the material obtained, as animal feed, was tested on broiler chickens. The results indicated that soybean meal protein in broiler diets, can be replaced by the protein of this product up to 40% without any reduction of the weight gain of the birds.|Keywords: Biomass, Food Wastes, Recycling, Solar Drying of Wastes, Feed from Wastes