Uso da biomassa florestal como estratégia de redução dos gases de efeito estufa: estudo de caso na fumicultura do sul do Brasil /RS

Abstract

Fumiculture is an activity of great economic importance in the South of Brazil and requires annually a large volume of forest biomass used in the curing process of tobacco leaves and accounting for almost 10% of production costs. Complete combustion of wood produces water vapor, CO2, heat and non-combustible ash. When combustion is incomplete, it occurs to the formation of CO, hydrocarbons and other gases. As an alternative to firewood, the use of agroindustrial waste, such as sawdust, is promising, since it gives adequate destination to these wastes, reducing the emission of pollutants (methane) in their decomposition, besides the lower cost and easy handling, but the high variability ends up reducing the useful value heat. One option is pellets, which in addition to homogeneous, have superior properties during combustion and lower greenhouse gas emissions (GHG). The objective of this work was to analyze new sources of forest biomass, aiming at energy efficiency and the control and reduction of GHG emissions, especially by controlling the quality of biofuels. In the two farms of the State of Rio Grande do Sul, with different models of curing units, the biomass consumption of firewood, sawdust and pellets, the production of ashes after combustion, and emissions of combustion gases were monitored. Samples were collected for physical-chemical analysis of biomass qualification and a financial analysis was also performed. Despite having inferior chemical characteristics, the sawdust had inferior consumption to firewood. Pellets presented the best physic-chemical characteristics for energy, as well as lower consumption and lower CO2 emission rates. However, financially it needs an increase in the supply and reduction of the sale price. In decision making to choose which biomass and technology to use, the producer must take into account the final quality of the product, improvements in ergonomic and health conditions, storage area, improvement in air quality, among others.