Studying the Effects of Pressure, Mold Diameter, Moisture Content and Particle Size on Energy Consumption for Compression in Producing Dairy Cattle Manure Pellets

Abstract

Normally, due to low specific gravity, the transportation of manure fertilizers is difficult and expensive. Reducing the volume of the manure by compression in pellet form is one way to facilitate transportation and decrease the costs. Information on Physical and mechanical properties of raw materials and energy consumption are required in the pelleting process. In this research, dairy cattle manure, sieved by a two-level mesh of 30 and 50, in five moisture levels of 15,17.5, 20, 22.5 and 25% and three pressure levels of 50, 100 and 150 MPa by a hydraulic press with mold diameters of 8 and 6 mm was studied. The results of the tests were analyzed by using EXCEL and MATLAB software. The findings indicated that the energy consumption for compression in mold diameter 6 was higher at all the three pressure levels of 50, 100 and 150 for mesh levels of 30 and 50 in comparison with that of mold diameter 8. The results also revealed that for both mold diameters 6 and 8 in each of the three pressure levels in mesh 30, energy consumption, first, increased as the moisture level increased from 15 to 20%, then it decreased following am increase in moisture level from 20 to 25%. However, a reduction in energy consumption was noticed as the moisture increased from 15 to 25% in mesh 50. Furthermore, the energy consumption of compression at pressure 150 turned out to be greater than those at pressure levels 100 and 50 MPa, and at pressure 100 more energy could be consumed.