Measurement and modeling of advanced coal conversion processes, Volume I, Part 2. Final report, September 1986--September 1993

Abstract

we are grateful for their advice and technical guidance. We wish to acknowledge the significant contributions of Professor Eric M. Suuberg of Brown University in the areas of char reactivity, pyrolysis modeling and pyrolysis kinetics. Prof. Philip E. Best of the University of Connecticut made significant contributions in the areas of coal and char optical properties, modeling of coal viscosity and swelling, and FT-IR ernission/transmission (En) tomography. in addition to the authors listed on the title page, the Senior Investigators at Advanced Fuel Research, Inc. (AFR) included Ms. Sylvie Charpenay, Dr. Zhen-Zhong Yu, and Dr. Yuxin Zhao for subtask 2.a., Mr. James R. Markham for subtask 2.c., and Dr. Marek A. Wojtowicz for subtask 2.d. The preparations of the manuscript and illustrations was ably performed at AFR by Karin Dutton, Margaret Lane, and Lori Bellone. II.E.l-1.II . E . 1-2 .ll.E.2-I. ll.E.2-2. ll.E.2-3.ll.E.3-1.II.E.4-1.ll.E.6-1. I I . E.6-2.ll.E.6-3. I xv EXECUTIVE SUMMARYThe overall objective of this program was the development of a predictive capability for the design, scale up, simulation, control and feedstock evaluation in advanced coal conversion devices. This technology is important to reduce the technical and economic risks inherent in utilizing coal, a feedstock whose variable and often unexpected behavior presents a significant challenge. This program merged significant advances made at Advanced Fuel Research, Inc. (AFR) in measuring and quantitatively describing the mechanisms in coal conversion behavior, with technology developed at Brigham Young University (BYU) in comprehensive computer codes for mechanistic modeling of entrained-bed gasification. Additional capabilities in predicting pollutant formation were implemented and the technology was expanded to fixed-bed reactors.The foundation to describe coal-specific conversion behavior was AFRs Functional Group (FG) and Devolatilization, Vaporization and Crosslinking (DVC) models, developed under previous and on-going METC sponsored programs. These models have demonstrated the capability to describe the time dependent evolution of individual gas species, and the amount and characteristics of tar and char. The combined FG-DVC model was integrated with BYU's comprehensive two-dimensional reactor model for combustion and gasification, PCGC-2, and a one-dimensional model for fixed-bed gasifiers, FBED-I . The program included: i) validation of the submodels by comparison with laboratory data obtained in this program, ii) extensive validation of the modified comprehensive codes by comparison of predicted results with data from bench-scale and process scale investigations of gasification, mild gasification and combustion of coal or coal-derived products, and iii) development of well documented user friendly software applicable to a "workstation" environment. The progress during the program is summarized below.For Subtask 2.a., the processes described were: 1) tar formation mechanisms and kinetics; 2) gas formation mechanism...