Open AccessTOXIC SUBSTANCES FROM COAL COMBUSTION A COMPREHENSIVE ASSESSMENT
Author(s) -
A KOLKER,
AF SAROFIM,
CA PALMER,
FE HUGGINS,
GP HUFFMAN,
J LIGHTY,
JJ HELBLE,
JOL WENDT,
MR AMES,
N YAP,
R FINKELMAN,
R MAMANI-PACO,
SJ MROCZKOWSKY,
T PANAGIOTOU,
W SEAMES
Publication year - 1999
Language(s) - English
Resource type - Reports
DOI - 10.2172/8847
Subject(s) - fly ash , combustion , coal , char , coal combustion products , pulverized coal fired boiler , sulfur , waste management , environmental chemistry , chemistry , vaporization , environmental science , mineralogy , engineering , organic chemistry
The technical objectives of this project are: (a) To identify the effect of the mode-of-occurrence of toxic elements in coal on the partitioning of these elements among vapor, submicron fume, and fly ash during the combustion of pulverized coal, (b) To identify the mechanisms governing the post-vaporization interaction of toxic elements and major minerals or unburnt char, (c) To determine the effect of combustion environment (i.e., fuel rich or fuel lean) on the partitioning of trace elements among vapor, submicron fume, and fly ash during the combustion of pulverized coal, (d) To model the partitioning of toxic elements among various chemical species in the vapor phase and between the vapor phase and complex aluminosilicate melts, (e) To develop the new Toxics Partitioning Engineering Model (ToPEM), applicable to all combustion conditions including new fuels and coal blends, low-NO{sub x} combustion systems, and new power generation plants. A description of the work plan for accomplishing these objectives is presented in Section 2.1 of this report. The work discussed in this report covers the reporting period from 1 October 1998 to 31 December 1998. During this quarter, basic coal testing at USGS was completed. Total sulfur contents range from 0.43 wt-% in the Wyodak to 2.68 wt-% in the Ohio sample. In the North Dakota and Ohio samples, about half of the total sulfur is pyritic and half is organic. The North Dakota sample also contains a minor amount of sulfate, consistent with the presence of barite in this sample. In the Wyodak sample, the majority of the sulfur is organic. Preliminary mineralogy of the three Phase II coals was determined by SEM/EDX. The Ohio coal contains all of the five most common major phases: quartz, illitic clay, kaolinitic clay, pyrite and calcite. Based on this preliminary work, the North Dakota sample appears to lack both kaolinite and calcite, and the Wyodak sample appears to lack calcite. Subsequent SEM work will attempt to reconfirm the basic findings presented here, and identify additional trace phases that could host the elements of interest in this study