Formation of tar and its characterization during air–steam gasification of sawdust in a fluidized bed reactor

Abstract The sawdust tar was generated from air–steam gasification in the fluidized bed reactor at atmospheric pressure. The gasification temperature and mass ratio of steam to sawdust were used as adjustable variables with which the amount of sawdust tar formation and the corresponding tar properties. Gel permeation chromatography (GPC) coupled with diode array detector (DAD) was employed to analyze the tar. It was found that the molecular weight distribution (MWD) of tar was unchanged under investigated conditions. The majority of the tar components are aromatic compounds, paraffin with conjugated bonds and olefin. Tar molecular weight (MW) depends on the H free radical amount, which is related to the steam added during the gasification. The steam can prevent the polymerization reaction and more conjugated side-chain compounds would be formed. In the end, the sawdust tar formation process has been described from the tar structure obtained.

[1]  José M. Encinar,et al.  Steam gasification of Cynara cardunculus L.: influence of variables , 2002 .

[2]  Jie Feng,et al.  Characterization of tar from sawdust gasified in the pressurized fluidized bed , 2007 .

[3]  D. Świerczyński,et al.  Steam reforming of tar from a biomass gasification process over Ni/olivine catalyst using toluene as a model compound , 2007 .

[4]  Kunio Yoshikawa,et al.  Potential applications of high-temperature air/steam-blown gasification and pyrolysis systems , 2005 .

[5]  S. Rapagnà.  Steam-gasification of biomass in a fluidised-bed of olivine particles. , 2000 .

[6]  Chuang-zhi Wu,et al.  Hydrogen-rich gas production from biomass air and oxygen/steam gasification in a downdraft gasifier , 2007 .

[7]  Kj Krzysztof Ptasinski,et al.  Olivine as tar removal catalyst for biomass gasifiers: Catalyst characterization , 2005 .

[8]  Thomas A. Milne,et al.  Molecular characterization of the pyrolysis of biomass , 1987 .

[9]  R. Alén,et al.  Formation of the main degradation compound groups from wood and its components during pyrolysis , 1996 .

[10]  W. Blasiak,et al.  Effect of operating conditions on tar and gas composition in high temperature air/steam gasification (HTAG) of plastic containing waste , 2006 .

[11]  G. Taralas,et al.  Modeling the Thermal Destruction of Toluene (C7H8) as Tar-Related Species for Fuel Gas Cleanup , 2003 .

[12]  Kunio Yoshikawa,et al.  Performance optimization of two-staged gasification system for woody biomass , 2007 .

[13]  Toshiaki Hanaoka,et al.  Effect of woody biomass components on air-steam gasification , 2005 .

[14]  F. Pinto,et al.  Effect of experimental conditions on co-gasification of coal, biomass and plastics wastes with air/steam mixtures in a fluidized bed system☆ , 2003 .

[15]  P. U. Foscolo,et al.  Catalytic gasification of biomass to produce hydrogen rich gas , 1998 .

[16]  Kj Krzysztof Ptasinski,et al.  Pretreated olivine as tar removal catalyst for biomass gasifiers : investigation using naphthalene as model biomass tar , 2005 .

[17]  A. Krause,et al.  Steam Reforming of Gasification Gas Tar over Dolomite with Benzene as a Model Compound , 1999 .

[18]  Isabel Cabrita,et al.  The study of reactions influencing the biomass steam gasification process , 2003 .

[19]  M. Aznar,et al.  Biomass gasification in atmospheric and bubbling fluidized bed: effect of the type of gasifying agent on the product distribution , 1999 .

[20]  Ayhan Demirbas,et al.  Mechanisms of liquefaction and pyrolysis reactions of biomass , 2000 .

[21]  Daniel Montané,et al.  Steam reforming model compounds of biomass gasification tars: conversion at different operating conditions and tendency towards coke formation , 2001 .

[22]  Robert C. Brown,et al.  Steam reforming of tar compounds over Ni/olivine catalysts doped with CeO2 , 2007 .

[23]  W. Blasiak,et al.  High-temperature air and steam gasification of densified biofuels , 2004 .

[24]  D. Świerczyński,et al.  Study of steam reforming of toluene used as model compound of tar produced by biomass gasification , 2008 .