Effects of solvent thermal treatment on the functional groups transformation and pyrolysis kinetics of Indonesian lignite
Creators
Description
Highlights: • Functional groups transformation were analyzed using FTIR and 13C NMR. • Relative percentage of functional group was semi-quantitatively calculated. • Oxygen-containing functional group was replaced by hydrogen or carbon-substituent. • Oxygen-loss was attributed to the loss of carbonyl, dihydric phenol and methoxyl. • Lower reactivity of pyrolysis was observed for the lignite upgrading at 300 °C. - Abstract: Organic solvent upgrading Indonesian lignite was performed in a 1 L autoclave under moderate temperature. The chemical structure and functional groups transformation of lignite upgraded by two organic solvents (ethanol and n-hexane) were analyzed to explore the upgrading mechanism of solvent thermal treatment by using Fourier transform infrared (FTIR) and 13C nuclear magnetic resonance (NMR). In addition, the characteristics of pyrolysis of treated samples were investigated using thermo gravimetric (TG) to clarify the variance of pyrolysis reactivity. Results showed that the carbon content and calorific value of upgraded lignite were significantly improved, and H/C and O/C ratios of treated samples were significantly reduced with the temperature increasing. The relative percentage of carbonyl and carboxyl carbon, oxygenated aliphatic carbon and methoxyl carbon of lignite upgraded at 300 °C decreased by 20–30%. However, the carbon-substituted and protonated aromatic carbon at 120–135 ppm and protonated aromatic carbon at 90–120 ppm were significantly increased after lignite was upgraded by the two solvents at above 200 °C. These transformations indicated that oxygen-containing functional group was substituted by hydrogen or carbon-substituent as temperature increased, and were intensified at above 200 °C. In addition, oxygen-loss in the treated samples was attributed to the loss of carbonyl group at 175 ppm, dihydric phenol at 147 ppm, and methoxyl group at 55 ppm. The activation energy of upgraded lignite at 300 °C were higher than those of raw lignite and upgraded lignite at 100 and 200 °C, indicating the low reactivity of pyrolysis of the treated lignite with the temperature increasing
Availability note (English)
Available from http://dx.doi.org/10.1016/j.enconman.2015.06.047Additional details
Identifiers
- DOI
- 10.1016/j.enconman.2015.06.047;
- PII
- S0196-8904(15)00588-9;
Publishing Information
- Journal Title
- Energy Conversion and Management
- Journal Volume
- 103
- Journal Page Range
- p. 66-72
- ISSN
- 0196-8904
- CODEN
- ECMADL
INIS
- Country of Publication
- United Kingdom
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 47019014
- Subject category
- S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
- Descriptors DEI
- ACTIVATION ENERGY; AUTOCLAVES; CALORIFIC VALUE; CARBON; CARBON 13; CARBONYLS; ETHANOL; FOURIER TRANSFORM SPECTROMETERS; HEAT TREATMENTS; HEXANE; HYDROGEN; INFRARED SPECTRA; LIGNITE; NUCLEAR MAGNETIC RESONANCE; ORGANIC SOLVENTS; OXYGEN; PHENOL; PYROLYSIS; REACTION KINETICS; THERMAL GRAVIMETRIC ANALYSIS
- Descriptors DEC
- ALCOHOLS; ALKANES; AROMATICS; BROWN COAL; CARBON ISOTOPES; CARBONACEOUS MATERIALS; CHEMICAL ANALYSIS; CHEMICAL REACTIONS; COAL; COMBUSTION PROPERTIES; DECOMPOSITION; ELEMENTS; ENERGY; ENERGY SOURCES; EVEN-ODD NUCLEI; FOSSIL FUELS; FUELS; GRAVIMETRIC ANALYSIS; HYDROCARBONS; HYDROXY COMPOUNDS; ISOTOPES; KINETICS; LIGHT NUCLEI; MAGNETIC RESONANCE; MATERIALS; MEASURING INSTRUMENTS; NONAQUEOUS SOLVENTS; NONMETALS; NUCLEI; ORGANIC COMPOUNDS; PHENOLS; QUANTITATIVE CHEMICAL ANALYSIS; RESONANCE; SOLVENTS; SPECTRA; SPECTROMETERS; STABLE ISOTOPES; THERMAL ANALYSIS; THERMOCHEMICAL PROCESSES
Optional Information
- Copyright
- Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.