Turíbio Gomes Soares Neto

The tropical forest and fire emissions experiment: Trace gases emitted by smoldering logs and dung from deforestation and pasture fires in Brazil

[1]xa0Earlier work showed that Amazonian biomass burning produces both lofted and initially unlofted emissions in large amounts. A mobile, Fourier transform infrared spectrometer (FTIR) measured the unlofted emissions of 17 trace gases from residual smoldering combustion (RSC) of logs as part of the Tropical Forest and Fire Emissions Experiment (TROFFEE) during the 2004 Amazonian dry season. The RSC emissions were highly variable and the few earlier RSC measurements lay near the high end of combustion efficiency observed in this study. Fuel consumption by RSC was ∼5% of total for a planned deforestation fire. Much regional RSC probably occurs in the residual woody debris burned during pasture maintenance fires. RSC could increase estimated total fire emissions for the Amazon region by 20–50% for several important VOC. FTIR emissions measurements of burning dung (in a pasture) showed high emission ratios for acetic acid and ammonia to CO (6.6 ± 3.4% and 8.9 ± 2.1%). Large emissions of nitrogen containing trace gases from burning dung and crop waste could mean that biomass burning in India produces more particle mass than previously assumed. Measurements of late-stage kiln emissions suggested that VOC/CO may increase as carbonization is extended. A cook stove emitted many VOC and NH3 far outside the range observed for open wood cooking fires. Enclosed/vented cooking stoves may change the chemistry of the smoke that is emitted.

Comparative study for hardwood and softwood forest biomass: Chemical characterization, combustion phases and gas and particulate matter emissions

Two different types of typical Brazilian forest biomass were burned in the laboratory in order to compare their combustion characteristics and pollutant emissions. Approximately 2 kg of Amazon biomass (hardwood) and 2 kg of Araucaria biomass (softwood) were burned. Gaseous emissions of CO2, CO, and NOx and particulate matter smaller than 2.5 μm (PM2.5) were evaluated in the flaming and smoldering combustion phases. Temperature, burn rate, modified combustion efficiency, emissions factor, and particle diameter and concentration were studied. A continuous analyzer was used to quantify gas concentrations. A DataRam4 and a Cascade Impactor were used to sample PM2.5. Araucaria biomass (softwood) had a lignin content of 34.9%, higher than the 23.3% of the Amazon biomass (hardwood). CO2 and CO emissions factors seem to be influenced by lignin content. Maximum concentrations of CO2, NOx and PM2.5 were observed in the flaming phase.