volume: 42, issue:
The use of sugarcane bagasse, straw, and chaff for electrical power generation in sugar-ethanol mills has been established; more recently, the recovery of forest biomass has been increasing in an attempt to reduce the use of fossil fuels and to increase electrical power generation focused on self-consumption. The potential for power generation in this segment is considerable, but the use of biomass in cogeneration processes depends on an attractive return on investments. This study was designed to analyze the economic feasibility of investment in thermal and electrical power generation equipment that makes it possible to use forest and logging residues and wood chips to replace the current gas-fired power generation in an engineered wood panel industry facility (Scenario 1) or investment only in thermal generation equipment (Scenario 2). Results showed that the investment to replace natural gas with forest biomass is economically viable not only for the generation of both types of energy but also for the generation of thermal energy itself. High costs of energy inputs such as natural gas and electricity for the industry explain the results, despite the requirement for high investments in cogeneration systems.
volume: 42, issue:
The natural drying of fuelwood is a common practice to improve its quality and increase the efficiency in the biomass-based energy supply chain. The objective of this work was to analyze the effect of seasons on the physical and chemical properties of wood logs stored in piles for energy purposes. The logs of Eucalyptus urophylla were stored in two periods of 160 days each throughout the year, autumn–winter (dry season) and spring–summer (rainy season). During the 320 days, the moisture content of wood and the weather parameters were measured daily. After the natural drying, the moisture content (wet basis) of wood reached 29.6%, and there was an increase of 47.6% in the low heating value (12.4 MJ kg-1 wet basis) after the storage in the autumn–winter, which is the most suitable period for air–drying of logs. The rainy storage reduced the higher heating value of wood, which suggested a biological degradation of biomass.
volume: 45, issue:
In recent years, fully mechanized planters have gained attention in Brazil on flat to steep terrain. A field study was conducted to analyze the potential of a planting machine composed of a hydraulic crawler excavator and a planter unit to perform soil preparation and planting in two slope classes and two conditions of slash presence. The experimental area was divided according to slope – undulating (8% to 20%) and strong undulating (20% to 45%) – and the presence of slash. Slope class did not significantly affect productivity, nor was there a significant interaction effect between the slope and slash factors. The presence of slash proved to be statistically different, with mean productivity of 236 seedlings hour-1 when reloading the carousel in an area without harvesting slash. Tree planting machine utilization was 75.13%, and the mechanical availability was 79.6%. The presence of slash significantly reduced the tree planting machine productivity, including the seedling reloading time, suggesting a newer research line for fasters reloading seedling systems.