Influence of Illinois No 5 Springfield Coal Lithotypes and Brazil Block Cannel on the Oxidative Hydrothermal Dissolution (OHD) Process
Vishnu Srinivasaraghavan, Sue M. Rimmer, Amberly Tobin, Mohammad Rahman, and Ken Anderson
The influence of petrographic composition on the Oxidative Hydrothermal Dissolution (OHD) process was examined using lithotypes from the Springfield (No. 5) coal seam and the Brazil Block seam, focusing on petrography, conversion, and final products. OHD is a coal conversion technique that reacts coal with minor amounts of molecular oxygen (introduced in the form of peroxide) in liquid water at 300°C to result in a mild oxidation of the sample. This effectively breaks up the macromolecular structure to release low-molecular-weight organic products. Coal lithotype samples: vitrain, clarain, fusain, and cannel were run in the OHD reactor for eight minutes each. The petrography and conversion percentage were determined on the residue (leftover material in the reactor) whereas the liquid product was analyzed by GCMS. Petrographic analysis of the vitrain, clarain, and cannel displayed distinct reaction rims and an associated increase in reflectance for the vitrinite macerals. Liptinite macerals started to disappear indicating its ready dissolution in the reaction whereas the fusain sample showed a slight increase in reflectance of the inertinite macerals. The fusain and clarain displayed the highest conversion of intial weight with an average of 27.7% and 27.5% respectively. The vitrain sample had 26.9% and the cannel had 22.9%. All four lithotypes produced a similar suite of products but relative abundances were different. Major families of products included di- substituted methoxy benzenes, mono-substituted methoxy benzoic acids, hydroxyl-substituted benzoic acids, methyl-substituted benzoic acids, disubstituted carboxylic acids, and tri- substituted carboxylic acids. The most abundant peak in all three samples, 3-methoxy benzoic acid was the largest in the cannel followed by the vitrain, fusain and clarain.
AAPG Search and Discovery Article #90182©2013 AAPG/SEG Student Expo, Houston, Texas, September 16-17, 2013