Evaluating the effect of potassium on cellulose pyrolysis reaction kinetics

Abstract This paper proposes modifications to an existing cellulose pyrolysis mechanism in order to include the effect of potassium on product yields and composition. The changes in activation energies and pre-exponential factors due to potassium were evaluated based on the experimental data collected from pyrolysis of cellulose samples treated with different levels of potassium (0–1% mass fraction). The experiments were performed in a pyrolysis reactor coupled to a molecular beam mass spectrometer (MBMS). Principal component analysis (PCA) performed on the collected data revealed that cellulose pyrolysis products could be divided into two groups: anhydrosugars and other fragmentation products (hydroxyacetaldehyde, 5-hydroxymethylfurfural, acetyl compounds). Multivariate curve resolution (MCR) was used to extract the time resolved concentration score profiles of principal components. Kinetic tests revealed that potassium apparently inhibits the formation of anhydrosugars and catalyzes char formation. Therefore, the oil yield predicted at 500  ° C decreased from 87.9% from cellulose to 54.0% from cellulose with 0.5% mass fraction potassium treatment. The decrease in oil yield was accompanied by increased yield of char and gases produced via a catalyzed dehydration reaction. The predicted char and gas yield from cellulose were 3.7% and 8.4%, respectively. Introducing 0.5% mass fraction potassium treatment resulted in an increase of char yield to 12.1% and gas yield to 33.9%. The validation of the cellulose pyrolysis mechanism with experimental data from a fluidized-bed reactor, after this correction for potassium, showed good agreement with our results, with differences in product yields of up to 5%.

[1]  V. Putsche,et al.  Large-Scale Pyrolysis Oil Production: A Technology Assessment and Economic Analysis , 2006 .

[2]  G. N. Richards,et al.  INFLUENCE OF METAL IONS ON VOLATILE PRODUCTS OF PYROLYSIS OF WOOD , 1989 .

[3]  S. Vassilev,et al.  An overview of the composition and application of biomass ash. , 2013 .

[4]  Flavio Manenti,et al.  Kinetic modeling of the thermal degradation and combustion of biomass , 2014 .

[5]  Pushkaraj R. Patwardhan.  Understanding the product distribution from biomass fast pyrolysis , 2010 .

[6]  S. L. Madorsky,et al.  Thermal degradation of cellulosic materials , 1958 .

[7]  Abhijit Dutta,et al.  Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Fast Pyrolysis and Hydrotreating Bio-Oil Pathway , 2013 .

[8]  M. Antal,et al.  Simultaneous thermogravimetric-mass spectrometric studies of the thermal decomposition of biopolymers. 1. Avicel cellulose in the presence and absence of catalysts , 1988 .

[9]  Michael Jerry Antal,et al.  Biomass Pyrolysis: A Review of the Literature Part 1—Carbohydrate Pyrolysis , 1983 .

[10]  James P. Diebold,et al.  A unified, global model for the pyrolysis of cellulose , 1994 .

[11]  Shiro Saka,et al.  Different pyrolytic pathways of levoglucosan in vapor- and liquid/solid-phases , 2008 .

[12]  Desmond Radlein,et al.  Liquid products from the continuous flash pyrolysis of biomass , 1985 .

[13]  Raf Dewil,et al.  Fundamentals, kinetics and endothermicity of the biomass pyrolysis reaction , 2010 .

[14]  Colomba Di Blasi,et al.  Modeling chemical and physical processes of wood and biomass pyrolysis , 2008 .

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

[16]  S. Saka,et al.  Different action of alkali/alkaline earth metal chlorides on cellulose pyrolysis , 2008 .

[17]  S. Saka,et al.  Pyrolysis behavior of levoglucosan as an intermediate in cellulose pyrolysis: polymerization into polysaccharide as a key reaction to carbonized product formation , 2003, Journal of Wood Science.

[18]  J. Bellan,et al.  A Generalized Biomass Pyrolysis Model Based on Superimposed Cellulose, Hemicelluloseand Liqnin Kinetics , 1997 .

[19]  Paul T. Williams,et al.  The role of metal salts in the pyrolysis of biomass , 1994 .

[20]  Jack L. Ziegler,et al.  One dimensional steady-state circulating fluidized-bed reactor model for biomass fast pyrolysis , 2014 .

[21]  F. Shafizadeh.  Pyrolysis and Combustion of Cellulosic Materials , 1968 .

[22]  Ramin Mehrabian,et al.  Kinetic scheme of biomass pyrolysis considering secondary charring reactions , 2014 .

[23]  Stefan Czernik,et al.  Pretreatment of wood and cellulose for production of sugars by fast pyrolysis , 1989 .

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

[25]  H. Chum,et al.  Mass spectrometric studies of the thermal decomposition of carbohydrates using 13C-labeled cellulose and glucose. , 1996, Carbohydrate research.

[26]  Wolter Prins,et al.  Biomass Pyrolysis in a Fluidized Bed Reactor. Part 1: Literature Review and Model Simulations , 2005 .

[27]  Jan Baeyens,et al.  Modeling CFB biomass pyrolysis reactors , 2008 .

[28]  J. Abedi,et al.  A simplified model for biomass pyrolysis in a fluidized bed reactor , 2010 .

[29]  S. Vassilev,et al.  An overview of the composition and application of biomass ash. Part 1. Phase-mineral and chemical composition and classification , 2013 .

[30]  C. Ruckebusch,et al.  Multivariate curve resolution: a review of advanced and tailored applications and challenges. , 2013, Analytica chimica acta.

[31]  Daren E. Daugaard,et al.  Techno-Economic Analysis of Biomass Fast Pyrolysis to Transportation Fuels , 2010 .

[32]  Shiro Saka,et al.  Secondary decomposition of levoglucosan in pyrolytic production from cellulosic biomass , 2009 .

[33]  Weihong Yang,et al.  Computational fluid dynamics modeling of biomass fast pyrolysis in a fluidized bed reactor, using a comprehensive chemistry scheme , 2014 .

[34]  J. Satrio,et al.  Influence of inorganic salts on the primary pyrolysis products of cellulose. , 2010, Bioresource technology.

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