Biomass pyrolysis experiments in an analytical entrained flow reactor between 1073K and 1273K

Abstract

Experiments are performed in an entrained flow reactor to better understand the kinetic processes involved in biomass pyrolysis under high temperatures (1073-1273 K) and fast heating condition (>500 K s À1 ). The influence of the particle size (0.4 and 1.1 mm), of the temperature (1073-1273 K), of the presence of steam in the gas atmosphere (0 and 20 vol%) and of the residence time (between 0.7 and 3.5 s for gas) on conversion and selectivity is studied. Under these conditions, the particle size is the most crucial parameter that influences decomposition. For 1.1 mm particles, pyrolysis requires more than 0.5 s and heat transfer processes are limiting. For 0.4 mm particles, pyrolysis seems to be finished before 0.5 s. More than 70 wt% of gas is produced. Forty percent of the initial carbon is found in CO; less than 5% is found in CO 2 . The hydrogen content is almost equally distributed among H 2 , H 2 O and light hydrocarbons (CH 4 , C 2 H 2 , C 2 H 4 ). Under these conditions, the evolution of the produced gas mixture is not very significant during the first few seconds, even if there seems to be some reactions between H 2 , the C 2 and tars.

Pyrolysis of wood at high temperature: The influence of experimental parameters on gaseous products

“…It is likely that it was similar for both particle sizes, which could explain the similarity in the gases produced. In these conditions, this result shows that for both particle sizes there is no heat and mass transfer limitation for the solid-gas reaction, which is in accordance to [3].…”

“…Because of tension on petroleum cost, second generation biofuels produced by Fischer-Tropsch synthesis after biomass gasification show an increasing interest. The physical and chemical mechanisms involved in biomass steam gasification are still poorly understood [3], especially under high temperatures (1073 K b T b 1273 K) and high heating rate (N10 3 K s − 1 ). Our work focuses on processes occurring at the particle scale during the first seconds of the transformation.…”

“…This reactor is an interesting analytical tool to study the global reaction of flash pyrolysis [3,10,[13][14][15][16][17][18][19], since very high heating rates of the particles can be obtained. Moreover, the residence time can be varied over a range of a few seconds, and the particles can be assumed to be isolated from each other, which makes interpretation easier [14,17].…”

Pyrolysis of waste biomass: investigation of fast pyrolysis and slow pyrolysis process conditions on product yield and gas composition

“…The hydrogen yield was significantly increased with temperature and there was a consequent decrease in methane and C 1 -C 4 hydrocarbons. Dupont et al 22 investigated the fast pyrolysis of pine and spruce wood in an entrained flow reactor.…”

Air Gasification of Malaysia Agricultural Waste in a Fluidized Bed Gasifier: Hydrogen Production Performance

“…The pharmaceutical industries use hydrogen to make vitamins and other pharmaceutical products. Hydrogen is mixed with inert gases to obtain a reducing atmosphere that is required for many applications in the metallurgical industry such as heat treating steel and welding (Delgado et al, 1997 andDupont et al, 2008). In 2005, the overall U.S. hydrogen market is estimated at $798.1 million and it is expected to rise to $1,605.3 million for U.S. and $740 million for European in 2010 (Keizai, 2005).…”