Research on low temperature drying characteristics of different types of manure and biogas residue

For the biogas project which does not have the ability to return to the field nearby, the outlet of biogas residue is one of the important bottlenecks restricting the development of biogas engineering. Deep dehydration and drying is a reliable basis for commercial utilization of biogas residue, especially combined with waste heat utilization of cogeneration of biogas. Therefore, three kinds of biogas residue raw materials were dried at low temperature by hot drying method in this paper. The drying temperature, the thickness of biogas residue and the backmixing amount of dry biogas residue were selected as three influencing factors. The drying time, drying rate and residual water ratio were taken as dependent variables. The drying characteristic curve of biogas residue was obtained, and the influence of each factor on the drying process of biogas residue was analyzed and compared. The results showed that the drying time of three kinds of biogas residue decreased with the increase of drying temperature. At the same temperature, the drying time decreases with the decrease of thickness. The dry biogas residue backmixing can’t optimize the drying characteristics and even increase the drying energy consumption.