Biomass torrefaction under different oxygen concentrations and its effect on the composition of the solid by-product

BIOMASS TORREFACTION UNDER DIFFERENT OXYGEN

CONCENTRATIONS AND ITS EFFECT ON THE

COMPOSITION OF THE SOLID BY-PRODUCT

1. Is it necessary to maintain a totally inert atmosphere for torrefaction? 2. Does the increase in oxygen content affect end-product quality?

Lucélia MACEDO1_{*, Patrick ROUSSET}2_{, Jean-Michel COMMANDRÉ}2_{, Alessandro MOREIRA}1

Objective: Investigate the thermal reactivity of Eucalyptus grandis during torrefaction under different oxygen concentrations by examining the relationship between mass loss and the physical and chemical properties of the solid by-product .

2% 6% 10% 21% Oxygen concentration Biomass

Effect of the oxygen concentration on the conversion rate for both temperatures 240 and 280°C. For each group, the means with the same letter were not significantly different at a probability of 5% with regard to Tukey’s test.

Classification by Tukey’s test of averaged results for the response variables considering 2 replicates per treatment. For each group, the means with the same letter were not significantly different at 5% (α = 0.05).

Experimental study: Eucalyptus grandis

Temp. (°C): 240, 280 Heating rate (°C/min): 4 Residence time (min): 60

1_{Laboratório de Produtos Florestais –} LPF/ Serviço Florestal Brasileiro, Brasília, Brazil:

lucelia.macedo@florestal.gov.br alessandro.moneira@florestal.gov.br

2_{Biomass-Energy Unit, CIRAD:}

patrick.rousset@cirad.fr commandre@cirad.fr * Corresponding author: MSc Lucelia Macedo Tel.: (55) 61 2028-7230 E-mail:ucelia.macedo@florestal.gov.br

For both temperatures (240 and 280°C) the oxygen content did not significantly affect the characteristics of the end-product.
The increase in oxygen content did not

significantly affect the conversion rate α.
The results show that it is necessary to maintain an inert atmosphere above 280°C. a a a a c b b b a a a a a ab b b b 40 44 48 52 56 60 64 2 6 10 21 2 6 10 21 240 °C 280 °C Li g n in ( % ) Oxygen concentration a a a a b b b b 50,00 52,00 54,00 56,00 58,00 60,00 2 6 10 21 2 6 10 21 240 °C 280 °C C ( % ) Oxygen concentration