Thermodynamic modelling of fate and removal of alkali species and sour gases from biomass gasification for production of biofuels

The development of advanced synthesis gas cleaning technologies based on chemical conversion and physical separation can improve the efficiency of gasification processes for production of biofuels. This paper outlines thermodynamic equilibrium calculations on the release and removal of alkali species and sour gases during gasification of 24 different types of herbaceous and woody biomass under the conditions of the gasifier in Güssing, Austria. In general, the calculation results are in good agreement with former experimental results. The composition of the gasifier derived as well as the cleaned gas strongly depends on the used feedstock. The alkali concentration can be limited to values below 100 ppbv using aluminosilicates at 850 °C. The H2S concentration cannot be limited to values below 200 ppmv using conventional Ca- or Cu-based sorbents but can be limited to values below 1 ppmv by stabilised BaO at 850 °C. The HCl concentration can be limited to values below 1 ppmv by alkali carbonates at temperatures below 550 °C.

[1]  H. Katalambula,et al.  Mineral attachment to calcium-based sorbent particles during in situ desulfurization in coal gasification processes , 2001 .

[2]  L. F. D. Diego,et al.  Factors affecting the H2S reaction with noncalcined limestones and half-calcined dolomites , 1999 .

[3]  F. Shadman,et al.  The kinetics and mechanism of alkali removal from flue gases by solid sorbents , 1990 .

[4]  D. Zachariadis,et al.  Flue gas desulfurization at high temperatures : A review , 2004 .

[5]  B. Haynes,et al.  Kinetic and thermodynamic analysis of the fate of sulphur compounds in gasification products , 2004 .

[6]  A. Atimtay,et al.  Zeolite-Supported Metal Oxide Sorbents for Hot-Gas Desulfurization , 1998 .

[7]  Michael Müller,et al.  Release of Inorganic Trace Elements During Gasification of Wood, Straw and Miscanthus , 2011 .

[8]  Karel Svoboda,et al.  Reaction between Hydrogen Sulfide and Limestone Calcines , 2002 .

[9]  S. Lynn,et al.  KINETIC AND STRUCTURAL STUDIES OF CALCIUM-BASED SORBENTS FOR HIGH-TEMPERATURE COAL-GAS DESULFURIZATION , 1996 .

[10]  Michael Müller,et al.  Theoretical Evaluation of Feedstock Gasification Using H2/C Ratio and ROC as Main Input Variables , 2010 .

[11]  S. V. Sotirchos,et al.  Performance of Porous CaO Obtained from the Decomposition of Calcium-Enriched Bio-Oil as Sorbent for SO2 and H2S Removal , 2004 .

[12]  Michael Müller,et al.  Chemical Hot Gas Cleaning Concept for the "CHRISGAS" Process , 2011 .

[13]  G. Towler,et al.  Removal Of H2S from Coal Gas Using Limestone: Kinetic Considerations , 1994 .

[14]  Binlin Dou,et al.  Adsorption of alkali metal vapor from high-temperature coal-derived gas by solid sorbents , 2003 .

[15]  Michael Müller,et al.  Laboratory investigations on chemical hot gas cleaning of inorganic trace elements for the “UNIQUE” process , 2013 .

[16]  Binlin Dou,et al.  High-Temperature HCl Removal with Sorbents in a Fixed-Bed Reactor , 2003 .

[17]  S. H. Lee,et al.  Removal of Gaseous Alkali Metal Compounds from Hot Flue Gas by Particulate Sorbents , 1980 .

[18]  Wei Wu,et al.  Prediction of the behaviors of H2S and HCl during gasification of selected residual biomass fuels by equilibrium calculation , 2005 .

[19]  Francisco García-Labiano,et al.  Utilization of Calcium Acetate and Calcium Magnesium Acetate for H2S Removal in Coal Gas Cleaning at High Temperatures , 1999 .

[20]  Douglas P. Harrison,et al.  Evaluation of candidate solids for high-temperature desulfurization of low-Btu gases , 1976 .

[21]  Farhang Shadman,et al.  Aluminosilicate Sorbents for Control of Alkali Vapors during Coal Combustion and Gasification , 1988 .

[22]  C. M. Kinoshita,et al.  An Experimental Investigation of Alkali Removal from Biomass Producer Gas Using a Fixed Bed of Solid Sorbent , 2001 .

[23]  T. Wheelock,et al.  Development of an advanced calcium-based sorbent for desulfurizing hot coal gas , 2001 .

[24]  Hofbauer Hermann,et al.  Biomass CHP Plant Güssing - A Success Story , 2002 .

[25]  Jpk Seville,et al.  Kinetics of HCl reactions with calcium and sodium sorbents for IGCC fuel gas cleaning , 1996 .

[26]  Kim Dam-Johansen,et al.  Hydrogen Chloride Reaction with Lime and Limestone : Kinetics and Sorption Capacity , 1992 .

[27]  Binlin Dou,et al.  HCl Removal and Chlorine Distribution in the Mass Transfer Zone of a Fixed-Bed Reactor at High Temperature , 2006 .

[28]  Carmen Clemente-Jul,et al.  Hot gas desulphurisation with dolomite sorbent in coal gasification , 2008 .

[29]  C. M. Kinoshita,et al.  A review of sorbent materials for fixed bed alkali getter systems in biomass gasifier combined cycle power generation applications , 1998 .

[30]  N. Verdone,et al.  Reaction kinetics of hydrogen chloride with sodium carbonate , 2006 .

[31]  Binlin Dou,et al.  A study on the reaction kinetics of HCl removal from high-temperature coal gas , 2001 .

[32]  T. Kojima,et al.  Desulfurization behavior of Ca-based absorbents under periodically changing condition between reducing and oxidizing atmosphere , 2001 .

[33]  S. Turn.  Chemical Equilibrium Prediction of Potassium, Sodium, and Chlorine Concentrations in the Product Gas from Biomass Gasification , 2007 .

[34]  A. Jensen,et al.  A kinetic study of gaseous potassium capture by coal minerals in a high temperature fixed-bed reactor , 2008 .