Spontaneous Generation of Tar Decomposition Promoter in a Biomass Steam Reformer

In situ steam reforming of tar from rapid pyrolysis of biomass was investigated experimentally using a two-stage reactor. Pulverized biomass was continuously fed into the rapid pyrolysis zone of the reactor at 773 K, where nascent volatiles and char were isolated from each other. The volatiles were then mixed with steam and introduced into the steam-reforming zone at 873 to 1073 K consisting of a fixed-bed of mesoporous alumina particles. The yield of tar heavier than naphthalene decreased as the amount of volatiles fed into the fixed-bed increased, and finally reached an undetectable level (well below 0.01% on a biomass carbon basis), leaving benzene and naphthalene with yields of 0.5–1% and below 0.05%, respectively. Coke was deposited over the alumina particles with a yield of 10–20%, and it acted as a catalyst active enough to eliminate polyaromatic hydrocarbons as the representative constituents of the heavy tar. Thus the mesoporous alumina played a dual role of eliminating tar and controlling the total yield of char and coke, and would therefore be suitable as the bed material for biomass gasification in two-stage gasifier with the bed material being circulated between the biomass pyrolysis/steam-reforming zone and the char/coke combustion zone.

[1]  Mordecai Shelef,et al.  Catalysis of carbon-steam gasification by ash components from two lignites , 1979 .

[2]  G. Olofsson,et al.  Catalytic Hot Gas Cleaning of Fuel Gas from an Air-Blown Pressurized Fluidized-Bed Gasifier , 2000 .

[3]  Mohammad Asadullah,et al.  Catalyst development for the gasification of biomass in the dual-bed gasifier , 2003 .

[4]  Mohammad Asadullah,et al.  A comparison of Rh/CeO2/SiO2 catalysts with steam reforming catalysts, dolomite and inert materials as bed materials in low throughput fluidized bed gasification systems. , 2004 .

[5]  María L. Salvador,et al.  Catalytic Steam Gasification of Pine Sawdust. Effect of Catalyst Weight/Biomass Flow Rate and Steam/Biomass Ratios on Gas Production and Composition , 1999 .

[6]  Clas Ekström,et al.  Catalytic Conversion of Tars, Carbon Black and Methane from Pyrolysis/Gasification of Biomass , 1985 .

[7]  D. Dayton,et al.  Direct Observation of Alkali Vapor Release during Biomass Combustion and Gasification. 1. Application of Molecular Beam/Mass Spectrometry to Switchgrass Combustion , 1995 .

[8]  Rolando Zanzi,et al.  Rapid high-temperature pyrolysis of biomass in a free-fall reactor , 1996 .

[9]  Ryo Yoshiie,et al.  Tar Capture Effect of Porous Particles for Biomass Fuel under Pyrolysis Conditions , 2003 .

[10]  José Corella,et al.  Biomass Gasification with Air in a Fluidized Bed: Exhaustive Tar Elimination with Commercial Steam Reforming Catalysts , 1999 .

[11]  Eddie G. Baker,et al.  Steam gasification of biomass with nickel secondary catalysts , 1987 .

[12]  A. Rao,et al.  Overview of combustion and gasification of rice husk in fluidized bed reactors , 1998 .

[13]  Lawrence J. Shadle,et al.  Coal Gasification in a Transport Reactor , 2001 .

[14]  A. Shamsi,et al.  Effects of Temperature, Pressure, and Carrier Gas on the Cracking of Coal Tar over a Char−Dolomite Mixture and Calcined Dolomite in a Fixed-Bed Reactor , 1998 .

[15]  D. Mckee,et al.  The catalyzed reaction of graphite with water vapor , 1978 .

[16]  Mohammad Asadullah,et al.  Demonstration of real biomass gasification drastically promoted by effective catalyst , 2003 .

[17]  Ian Narváez,et al.  Fresh Tar (from a Biomass Gasifier) Elimination over a Commercial Steam-Reforming Catalyst. Kinetics and Effect of Different Variables of Operation , 1997 .

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

[19]  A. Karabelas,et al.  Olive residues (cuttings and kernels) rapid pyrolysis product yields and kinetics , 2000 .

[20]  M. Antal,et al.  Cellulose Pyrolysis Kinetics: The Current State of Knowledge , 1995 .

[21]  L. García,et al.  Hydrogen production by steam gasification of biomass using Ni-Al coprecipitated catalysts promoted with magnesium , 2002 .

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

[23]  Krister Sjöström,et al.  Catalytic tar decomposition of biomass pyrolysis gas with a combination of dolomite and silica , 2002 .

[24]  Hermann Hofbauer,et al.  The FICFB — Gasification Process , 1997 .

[25]  Jun-ichiro Hayashi,et al.  Roles of inherent metallic species in secondary reactions of tar and char during rapid pyrolysis of brown coals in a drop-tube reactor ☆ , 2002 .

[26]  Wen Yang Wen,et al.  Catalytic pyrolysis of a coal tar in a fixed-bed reactor , 1984 .

[27]  Anthony V. Bridgwater,et al.  Developments in thermochemical biomass conversion , 1997 .

[28]  L. García,et al.  The effect of lanthanum on Ni–Al catalyst for catalytic steam gasification of pine sawdust , 2004 .

[29]  Ian Narváez,et al.  Performance of Different Dolomites on Hot Raw Gas Cleaning from Biomass Gasification with Air , 1997 .

[30]  Hermann Hofbauer,et al.  In-Bed Catalytic Tar Reduction in a Dual Fluidized Bed Biomass Steam Gasifier , 2004 .

[31]  Chun-Zhu Li,et al.  Fates and roles of alkali and alkaline earth metals during the pyrolysis of a Victorian brown coal , 2000 .

[32]  N. Papayannakos,et al.  Modelling of the pyrolysis of biomass particles. Studies on kinetics, thermal and heat transfer effects , 1991 .

[33]  José Corella,et al.  Biomass gasification in fluidized bed : where to locate the dolomite to improve gasification? , 1999 .

[34]  Javier Herguido,et al.  Fluidized Bed Steam Gasification of Biomass with Dolomite and with a Commercial FCC Catalyst , 1988 .

[35]  John G. Olsson,et al.  Alkali Metal Emission during Pyrolysis of Biomass , 1997 .

[36]  Thomas Nussbaumer,et al.  Mechanisms and kinetics of homogeneous secondary reactions of tar from continuous pyrolysis of wood chips , 2002 .

[37]  M. Asadullah,et al.  Catalyst Performance of Rh/CeO 2 /SiO 2 in the Pyrogasification of Biomass , 2003 .

[38]  L. K. Mudge,et al.  Methanol and ammonia from biomass. , 1984 .

[39]  E. G. Baker,et al.  The effect of catalysis on wood-gasification tar composition , 1986 .

[40]  Hongbin Zhao,et al.  Performance of a Nickel-Activated Candle Filter for Naphthalene Cracking in Synthetic Biomass Gasification Gas , 2000 .

[41]  J. Corella,et al.  Biomass Gasification with Air in a Fluidized Bed: Effect of the In-Bed Use of Dolomite under Different Operation Conditions , 1999 .

[42]  Anja Oasmaa,et al.  Fast Pyrolysis of Forestry Residue. 2. Physicochemical Composition of Product Liquid , 2003 .

[43]  Peter Arendt Jensen,et al.  Experimental Investigation of the Transformation and Release to Gas Phase of Potassium and Chlorine during Straw Pyrolysis , 2000 .

[44]  Mohammad Asadullah,et al.  Biomass Gasification to Hydrogen and Syngas at Low Temperature: Novel Catalytic System Using Fluidized-Bed Reactor , 2002 .

[45]  Andrew A. Suby,et al.  Catalytic destruction of tar in biomass derived producer gas , 2004 .

[46]  D. Mckee.  Catalysis of the graphite-water vapor reaction by alkaline earth salts , 1979 .

[47]  Luis Puigjaner,et al.  Removal of tar by secondary air in fluidised bed gasification of residual biomass and coal , 1999 .

[48]  A. Bell,et al.  Effect of alkali metal catalysts on gasification of coal char , 1978 .

[49]  José Corella,et al.  Commercial steam reforming catalysts to improve biomass gasification with steam-oxygen mixtures. 2: Catalytic tar removal , 1998 .

[50]  José Corella,et al.  Biomass Gasification: Produced Gas Upgrading by In-Bed Use of Dolomite , 1997 .

[51]  Kj Krzysztof Ptasinski,et al.  A review of the primary measures for tar elimination in biomass gasification processes , 2003 .

[52]  L. K. Mudge,et al.  Fundamentals of thermochemical biomass conversion , 1985 .

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

[54]  R. Vaidyeswaran,et al.  Smokeless fuel from carbonized sawdust. , 1981 .