ABSTRACT

Diversifying the Brazilian energy matrix by using residual biomass from planted forests requires searching for harvest technologies with sustainable applications. The aim of this study was to access the productive assessment and energy balance of grinding forest residues from full tree pine harvesting using a horizontal grinder in Brazil. A time study and moisture measurement were carried out at 15-year-old Pinus taeda L. stands located in the Santa Catarina State to determine mechanical delay, utilization rate, productivity per productive machine hour and production of a horizontal grinder in which energy balance was also calculated. For these variables, non-parametric bootstrap was performed, resampling a thousand times with replacement and producing new random samples, to calculate bias and confidence intervals at a 95% probability level. Non-working time consumed most of the scheduled machine hours, with only 46% being considered as working time. This was caused by the horizontal grinder’s travel time and time spent waiting for the transport vehicles. The horizontal grinder’s average productivities were 59 Mg per productive machine hour and 219 Mg per shift, considering the low machine utilization. The energy contained in the woodchips is 126.6 times higher than the energy consumed by the grinder, but this calculation only considers the grinding phase and excludes transport to the mill as well as the previous steps of stacking at the side of the field. The sustainability of this production is confirmed as the amount of energy consumed represents a small part of the potential present in the recovered forest residues.

摘要

通过使用来自人工林的残余生物质使巴西能源矩阵多样化，需要寻找具有可持续应用的收获技术。本研究的目的是获取在巴西使用卧式粉碎机对整棵松树收获的森林残留物进行粉碎的生产评估和能量平衡。对 15 年生火炬松进行了时间研究和水分测量L. 机架位于圣卡塔琳娜州，用于确定机械延迟、利用率、每生产机器小时的生产率以及水平磨床的产量，其中还计算了能量平衡。对于这些变量，执行非参数引导程序，重新采样一千次并产生新的随机样本，以 95% 的概率水平计算偏差和置信区间。非工作时间消耗了大部分预定的机器时间，只有 46% 被视为工作时间。这是由卧式磨床的行驶时间和等待运输车辆所花费的时间造成的。考虑到机器利用率低，卧式磨床的平均生产率为每生产机器小时 59 毫克和每班次 219 毫克。木片中所含的能量为 126。比研磨机消耗的能量高 6 倍，但此计算仅考虑研磨阶段，不包括运输至研磨机以及在田边堆放的先前步骤。这种生产的可持续性得到证实，因为消耗的能源量只占回收的森林残留物中存在的潜力的一小部分。