Application of uncertainty quantification methods for coal devolatilization kinetics in gasifier modeling

Abstract The focus of this research is to study sensitivity of input parameters in terms of chemical reaction kinetics of coal devolatilization using non-intrusive uncertainty quantification (UQ) methods. The effects of heating rate, pressure, and temperature on coal devolatilization have been considered. Variations in coal devolatilization kinetics and product yields were captured via Carbonaceous Chemistry for Computational Modeling (C3M) for operating conditions similar to the transport gasifier using PC Coal Lab (PCCL) kinetic package. Temperature, pressure and heating rate were considered as three input parameters, while the quantities of interest or response variables were mass fractions of CO, CO 2 , H 2 , tar, H 2 O, and CH 4 along with total volatile yield. A direct Monte Carlo-simulation-based approach was employed to perform the UQ analysis. The correlations among the response variables were investigated by computing a correlation matrix that supports the findings of yield of devolatilization reported by various experiments in the literature. Sensitivity study of the input parameters was analyzed by using the Sobol Total Indices methodology implemented in PSUADE, an open source UQ toolbox. These findings clearly demonstrate the pronounced effect of temperature on coal devolatilization product yields, and hence will be considered as a key parameter in future studies. The preliminary study presented in this paper paves a path for incorporating uncertainty caused by chemical reaction kinetics in computational fluid dynamics based modeling of coal gasifier systems and scale-up studies.

[1]  J. Hayashi,et al.  Reactions in Brown Coal Pyrolysis Responsible for Heating Rate Effect on Tar Yield , 2000 .

[2]  D. Saville,et al.  Time-resolved pyrolysis product distributions of softening coals , 1986 .

[3]  R. Kandiyoti,et al.  The effect of variations in time-temperature history on product distribution from coal pyrolysis , 1989 .

[4]  J. Sears,et al.  Coal pyrolysis at high temperatures and pressures , 1984 .

[5]  Hai Wang Formation of nascent soot and other condensed-phase materials in flames , 2011 .

[6]  Joseph W. Hogge,et al.  Coal Swelling Model for Pressurized High Particle Heating Rate Pyrolysis Applications , 2012 .

[7]  J. Markham,et al.  Kinetics of volatile product evolution in coal pyrolysis: experiment and theory , 1987 .

[8]  Aytekin Gel,et al.  Applying uncertainty quantification to multiphase flow computational fluid dynamics , 2013 .

[9]  W. Peters,et al.  An experimental and modeling study of softening coal pyrolysis , 1989 .

[10]  S. E. Zitney,et al.  Gasification CFD Modeling for Advanced Power Plant Simulations , 2005 .

[11]  Stefano Tarantola,et al.  Sensitivity Analysis in Practice: A Guide to Assessing Scientific Models , 2004 .

[12]  Qian Liu,et al.  Thermogravimetric study of the pyrolysis of two Chinese coals under pressure , 1997 .

[13]  Stephen Niksa,et al.  Impact of Pressure Variations on Coal Devolatilization Products. 2. Detailed Product Distributions from 1.0 MPa , 2004 .

[14]  W. Peters,et al.  Pressure and temperature effects in bituminous coal pyrolysis : experimental observations and a transient lumped-parameter model , 1994 .

[15]  Alan W. Scaroni,et al.  Effect of pressure on the devolatilization and swelling behaviour of a softening coal during rapid heating , 1991 .

[16]  T. Fletcher,et al.  Coal Swelling Model for High Heating Rate Pyrolysis Applications , 2011 .

[17]  Jack B. Howard,et al.  Coal devolatilization and hydrogastification , 1976 .

[18]  R. Jenkins,et al.  Thermoplastic properties of coal at elevated pressures: 1. Evaluation of a high-pressure microdilatometer , 1985 .

[19]  Manish Bhargava,et al.  KBR'S TRANSPORT GASIFIER (TRIG™) - AN ADVANCED GASIFICATION TECHNOLOGY FOR SNG PRODUCTION FROM LOW-RANK COALS , 2008 .

[20]  Christopher J. Roy,et al.  A comprehensive framework for verification, validation, and uncertainty quantification in scientific computing , 2011 .

[21]  Shiqiu Gao,et al.  Continuous high-temperature fluidized bed pyrolysis of coal in complex atmospheres: Product distribution and pyrolysis gas , 2012 .

[22]  Shuangzhe Liu,et al.  Global Sensitivity Analysis: The Primer by Andrea Saltelli, Marco Ratto, Terry Andres, Francesca Campolongo, Jessica Cariboni, Debora Gatelli, Michaela Saisana, Stefano Tarantola , 2008 .

[23]  T. Fletcher,et al.  Effects of Pressure on Coal Pyrolysis and Char Morphology , 2005 .

[24]  H. Zhu,et al.  Gas evolution kinetics of two coal samples during rapid pyrolysis , 2010 .

[25]  Ramana V. Grandhi,et al.  Quantification of model-form and predictive uncertainty for multi-physics simulation , 2011 .

[26]  W. Pan,et al.  Coal and Biomass Partial Gasification and Soot Properties in an Atmospheric Fluidized Bed , 2011 .

[27]  P. Arendt,et al.  Comparative investigations of coal pyrolysis under inert gas and H2 at low and high heating rates and pressures up to 10 MPa , 1981 .

[28]  I. Smith,et al.  Pyrolysis of coal at high temperatures , 1987 .

[29]  Lars-Peter Wiktorsson,et al.  Kinetic parameters for coal pyrolysis at low and high heating rates: a comparison of data from different laboratory equipment , 2000 .

[30]  Koichi Matsuoka,et al.  High-Pressure Coal Pyrolysis in a Drop Tube Furnace , 2003 .

[31]  D. G. Roberts,et al.  On the Effects of High Pressure and Heating Rate during Coal Pyrolysis on Char Gasification Reactivity , 2003 .

[32]  Kiran Chaudhari Development of Advanced Coal Devolatilization and Secondary Pyrolysis Kinetics Models for CFD (and process simulation) Codes , 2011 .

[33]  R. Hurt,et al.  Coal conversion submodels for design applications at elevated pressures. Part I. devolatilization and char oxidation , 2003 .

[34]  Saltelli Andrea,et al.  Global Sensitivity Analysis: The Primer , 2008 .

[35]  X. Fu,et al.  Study on kinetics of coal pyrolysis at different heating rates to produce hydrogen , 2013 .

[36]  R. Hurt,et al.  Char combustion reactivities for a suite of diverse solid fuels and char-forming organic model compounds , 2002 .