Análise técnica de um cavaqueador e caracterização energética de cavacos de biomassa da colheita de madeira

Abstract

This research aimed to carry out the operational assessment of mechanized system of processing of residues and the quality of biomass chips for energy production. The research was realized in a forestry company located in the northeast region of state of Santa Catarina, Brazil, contemplating the processing operations of the residual biomass of timber Pinus taeda harvesting. Initially was realized an operational analysis of chipper of the Vermeer brand, HG 6000 TX model in the processing execution of residues, through of a study of times and movements, being determined the mechanical availability, the operational efficiency, the productivity and the energy yield. Then, the quality was evaluated of residual biomass of timber harvesting stored in field in normal condition and from of chips processed and stored in industry under cover, in different time periods: 7 (witness), 30, 60, 90, 120, 150 and 180 days. Were evaluated the physical and chemical parameters of the chips in relation to the moisture content, apparent bulk density, calorific value and immediate chemical analysis. The amounts related to operational analysis and physical and chemical parameters of the chips in different storage periods were subjected to analysis of variance and average compared by Tukey test at 5% probability. The results showed that the operational efficiency and productivity of chipper of residues were affected by the displacement times and waiting the transport vehicles, with 31% and 29% of the total operational cycle time, respectively, indicating, thus the necessity of adjustments in sizing and logistics planning. Besides, there was wasting time with internal and external movements of the plots, which affected the productivity of the equipment. The average productivity of chipper in the processing of residual biomass of timber harvesting was of 27.3 ton.h-1 with a mechanical availability and efficiency operational of 86% and 46%, respectively. In relation the quality of the chips, the lower moisture contents were obtained for the treatment in the industry under shelter, being the 120 days the best period of storage of chips. The apparent density showed an average value of 100 kg.m-3 at 30 days, while the witness showed an average value of 184 kg.m-3. In relation at calorific power, the highest value was obtained at 30 days with the residues stored in the field with an average value of 4,792 Kcal.Kg-1, however, the treatments with greater stability of calorific power were the stocked in the industry. Finally, with relation to the ash contents, the best result was obtained in the treatment of storage of residues in the field at 30 days, with an average value of 0.9%, however again, the stability was observed only in treatments stocked in the industry. The chips produced from the residual biomass of timber harvesting and stored in the industry in the period between 30 and 90 days showed the best indexes for moisture contents, energy generation and ash contents. However, emphasized the highest quality in storage under in the industry in relation to chips produced from biomass stored in the field and exposed to weather conditions.