Simulation of macauba palm cultivation: an energy-balance and greenhouse gas emissions analysis

Abstract

ABSTRACTThe expansion of the production and use of bioenergy is one of the most efficient mechanisms to reduce greenhouse gas (GHG) emissions. Nevertheless, the environmental impact of the production processes for many raw materials remains unexplored. Several studies have pointed to macauba palm as a promising species for biofuel production in the tropics, but investigations on the environmental benefits of its cultivation have not been reported so far. In this work, an analysis of macauba production system in terms of GHG emissions and CO2 uptake has been conducted for a productive cycle. The energy conversion efficiency per unit area of land has been put in relationship with crop productivity and related to the dilution effect of production inputs. Simulation results estimate GHG emissions of 180 Mg CO2eq·ha-1 and a CO2 fixation ranging from 796 to 1137 Mg CO2eq·ha-1. The net energy balance would reach 512.3 GJ·ha-1 and energy efficiency would be 24.2 GJ·GJ-1. These results suggest that macauba would outperform traditional energy crops such as sugarcane, oil palm, sunflower, corn or jatropha in terms of efficiency. The domestication and exploitation in extensive farming of this species as an agroforestry crop, although still at an early stage, has a bright future.