Document Server@UHasselt >
Research >
Research publications >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/2194

Title: Characterization of sulfur functionalities of supercritical extracts from coals of different rank, using reductive pyrolysis
Authors: GRYGLEWICZ, Grazyna
Issue Date: 2004
Citation: ENERGY & FUELS, 18(5). p. 1595-1602
Abstract: The extracts obtained via supercritical fluid extraction (SFE) from three Polish coals of different rank, using toluene, toluene/2-propanol, and toluene/tetrahydrofuran (THF) mixtures, were subjected to reductive pyrolysis to determine their organic sulfur functionalities. The extraction yield was in the range of 11.4-43.1 wt %, depending on the type of solvent and coal. Toluene gave the highest extraction yield for medium-volatile bituminous coal, whereas a toluene/2-propanol mixture was the most effective in the case of lignite. The organic sulfur content in the resultant supercritical extracts amounted to 2.17-3.70 wt %. The atmospheric-pressure-temperature-programmed reduction technique coupled with potentiometric detection of H2S (APTPR) and mass spectrometry (AP-TPR-MS) were applied to monitor the sulfur-containing compounds. During this reductive pyrolysis, these compounds were hydrogenated to H2S at specific and discrete temperature intervals. The H2S AP-TPR recovery for supercritical extracts was in the range of 23-65 wt %. The results show that thiols, polysulfides, and/or elemental sulfur have the highest contribution to the detectable sulfur in supercritical extracts by AP-TPR. However, alkyl aryl sulfides, aryl sulfides, and thiophenes are also present in smaller amounts. A toluene/THF mixture, compared to the rest of solvents used, seems to have the greatest extraction ability toward thiols and polysulfides-containing coal fragments. It was proven that the higher rank coal subjected to the SFE, the higher the contribution of thiophenic sulfur into the H2S AP-TPR evolution profile in the range of 350-900 degreesC. The use of the AP-TPR setup coupled with a mass spectrometer instead of the potentiometric detection system has revealed the presence of alkanethiols, thiophene, and C-1- and C-2-thiophenes in the gaseous products of reductive pyrolysis. C-1-C-3 dibenzothiophenes, C-1-C-3 benzonaphthothiophenes, and C-1-C-2 dinaphthothiophenes can be observed in the evolved tar.
Notes: Wroclaw Univ Technol, Inst Chem & Technol Petr & Coal, PL-50344 Wroclaw, Poland. Limburgs Univ Ctr, CMK, Lab Appl Chem, B-3590 Diepenbeek, Belgium.Gryglewicz, G, Wroclaw Univ Technol, Inst Chem & Technol Petr & Coal, Ul Gdanska 7-9, PL-50344 Wroclaw, Poland.grazyna.gryglewicz@pwr.wroc.pl
URI: http://hdl.handle.net/1942/2194
DOI: 10.1021/ef0498869
ISI #: 000223976800051
ISSN: 0887-0624
Category: A1
Type: Journal Contribution
Validation: ecoom, 2005
Appears in Collections: Research publications

Files in This Item:

There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.