Publication detail
REGENERATED HUMIC ACIDS OBTAINED BY THE AIR OXIDATION OF SOUTH MORAVIAN LIGNITE. PART. 2. THERMOANALYTICAL CHARACTERIZATION OF PRODUCTS
CIHLÁŘ, Z. KUČERÍK, J.
Original Title
REGENERATED HUMIC ACIDS OBTAINED BY THE AIR OXIDATION OF SOUTH MORAVIAN LIGNITE. PART. 2. THERMOANALYTICAL CHARACTERIZATION OF PRODUCTS
Type
journal article - other
Language
English
Original Abstract
A sample of humic acid prepared from parental lignite and seven regenerated humic acids prepared from oxidized ones were extracted from South Moravian lignite. First, the samples were tested for their stabilities and degradabilities using thermogravimetry. It was shown that oxidation of lignite in static reactor at 85 C produced regenerated humic acids with an increasing content of labile part. The dependency of labile content was exponential-like and reached a constant value after 240 hours of oxidation. Increasing content of labile part in regenerated humic acids was also confirmed by measuring of heat accompanying the thermo-oxidative degradation using differential scanning calorimetry.The previously reported increase in number of ester bonds and the character of surface of prepared humic material was evaluated by moisture uptake measurement. Using thermogravimetry, the determination of the content of moisture adsorbed on the surface of humic samples after 21 days was carried out. In accordance with previous conclusions based on elemental analysis and yield of regenerated humic acids, the highest moisture content was observed for humic sample prepared in fluid reactor from lignite oxidized at 50 C for 72 hours and a sample extracted from lignite oxidized in static reactor at 85 C for 456 hours.
Keywords
lignite oxidation; regenerated humic acids; moisture uptake; thermal degradation
Authors
CIHLÁŘ, Z.; KUČERÍK, J.
RIV year
2010
Released
23. 12. 2010
Publisher
Slovnaft
Location
Slovenská Republika
ISBN
1335-3055
Periodical
Petroleum and Coal
Year of study
52
Number
4
State
Slovak Republic
Pages from
49
Pages to
55
Pages count
7
BibTex
@article{BUT50017,
author="Zdeněk {Cihlář} and Jiří {Kučerík}",
title="REGENERATED HUMIC ACIDS OBTAINED BY THE AIR OXIDATION OF SOUTH MORAVIAN LIGNITE. PART. 2. THERMOANALYTICAL CHARACTERIZATION OF PRODUCTS",
journal="Petroleum and Coal",
year="2010",
volume="52",
number="4",
pages="49--55",
issn="1335-3055"
}