Effects of oil content, pressure and temperature on physical and chemical properties of spruce pellets

Abstract

This work addresses an investigation on and comparison of the physical and chemical properties of Spruce wood powder which is mixed with Oil and compressed in pellets. This work was carried out from January 2014 to May 2014. Variations in wood power, moisture content, particle size or pre-treatment of powder have been investigation for many years. In recent years however, research has been focused on addition of different additive such as oil and lignin. This is because increasing the efficiency directly translates to saving cost and thus such studies has been primed as a key area for research. Variation in calorific values, strength and compressibility studies, water activity level were the primary field of interest, since these results is affected by compacting pressure and temperature. Studies was also conducted for the bulk density, ash content, moisture content and SEM and EDX analysis to identify the physical and chemical properties of the product. Studies indicated that the pellets with higher oil content had larger calorific values due to the addition of oil to it. Additional of oil also significantly decreased the strength of the pellets, since additional oil reduced the interfacial forces and capillary pressure. The water activity also reduced when oil was added to or compacting pressure was increased on the spruce power. The bulk density, ash content and moisture content remained significantly unaffected by the change of oil concentration. Optimal pressure and temperature the three pellets lied in the region of 150 MPa and 120C, since any addition of pressure or temperature no longer changes the physical and chemical properties significantly. Studies was also done to investigate the quantity of oil lost during the mixing and the pelleting process to ensure that the correct level of oil is being investigated.