AIR OXIDATION OF TURKISH BEYPAZARI LIGNITE .1. CHANGE OF STRUCTURAL CHARACTERISTICS IN OXIDATION REACTIONS AT 150-DEGREES-C

Date

1993-05-01

Author

AZIK, M
YURUM, Y
GAINES, AF

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

139
views

0
downloads

The oxidation of Beypazari lignite was carried out in air at 150-degrees-C for up to 168 h. Oxidized samples were withdrawn from a ventilated oven at different periods of time and characterized by elemental analysis, diffuse reflectance Fourier transform infrared (DRIFT), solid-state C-13 CP/MAS/TOSS NMR, and pyrolysis mass (Py-MS) spectroscopies. It was found that oxidation influenced the organic structure and the inorganics at different periods of the oxidation. Iron(II) sulfate was formed in 24 h, during which time there was almost no change of aliphatic CH2 and CH3 groups. After the formation of iron(II) sulfate, aliphatic CH2 and CH3 groups started to oxidize. Thus, the formation of iron(II) sulfate apparently prevented the oxidation of organic structure of Beypazari lignite during the first 24 h. The van Krevelen diagram (H/C vs O/C), the change of the O/H atomic ratio, and the rate of loss of aliphatic CH2 and CH3 groups showed the organic structure of Beypazari lignite to have continued in three stages. Aromatics seemed to be more stable than aliphatics during the oxidation process. The functional groups produced by the oxidation included ketones, carboxyls, and anhydrides but the major oxidation products were aryl esters. The abundance of CO2+, CO+, CH3COOH+, and SO2+ molecular ions increased in the pyrolysate of the oxidized sample whereas the molecular ions alkylphenols, dihydroxybenzenes, and alklynaphthalenes decreased after the oxidation.

Subject Keywords

Fuel Technology, Energy Engineering and Power Technology, General Chemical Engineering

URI

https://hdl.handle.net/11511/66816

Journal

ENERGY & FUELS

DOI

https://doi.org/10.1021/ef00039a006

Collections

Graduate School of Marine Sciences, Article

Suggestions

OpenMETU
Core

AIR OXIDATION OF TURKISH BEYPAZARI LIGNITE .2. EFFECT OF DEMINERALIZATION ON STRUCTURAL CHARACTERISTICS IN OXIDATION REACTIONS AT 150-DEGREES-C AZIK, M; YURUM, Y; GAINES, AF (American Chemical Society (ACS), 1994-01-01) Demineralized (HCl/HF) samples of Beypazari lignite were oxidized in air at 150 degrees C for up 120 h in a ventilated oven. Elemental analyses, diffuse reflectance Fourier transform infrared (DRIFT), solid-state C-13 CP/MAS/TOSS NMR, and pyrolysis mass (PY-MS) spectroscopies as well as solvent swelling were used for the characterization of the oxidized and unoxidized samples. It was found that the removal of 90.1% of the mineral matter from Beypazari lignite facilitated the access of oxygen into the coal s...
AIR OXIDATION OF TURKISH BEYPAZARI LIGNITE .3. CHANGE IN THE STRUCTURAL CHARACTERISTICS OF THE RESIDUE IN OXIDATION REACTIONS AT 150-DEGREES-C AZIK, M; YURUM, Y; GAINES, AF (American Chemical Society (ACS), 1994-05-01) Beypazari lignite was subsequently demineralized with HCl/HF and extracted by pyridine under supercritical conditions. The extracted residue was oxidized in air at 150-degrees-C for up to 120 h in a ventilated oven. Elemental analysis, diffuse reflectance Fourier transform infrared (DRIFT), solid-state C-13 CP/MAS/TOSS NMR, and pyrolysis mass (Py-MS) spectroscopic techniques were used for the structural characterization of the oxidized and unoxidized samples. It was found that the oxidation of the extracted...
ELECTROKINETICS OF OXIDIZED COAL SARIKAYA, M; OZBAYOGLU, G (Elsevier BV; 1990-01-01) Electrokinetic measurements were carried out in order to determine the properties of oxidized coal surfaces over a wide pH range both in the presence and absence of various metal ions and flotation collectors. It was found that polyvalent cations, such as Fe++, Fe+++ and Al+++ decreased the zeta potential to zero and then reversed the charge. In the presence of cationic collectors, the negative value of zeta potential of oxidized coal was driven positive, below 9.3 to 10.9 depending on the type and concentr...
SCANNING ELECTRON-MICROSCOPY OF TREATED BITUMINOUS COALS HUAI, HY; GAINES, AF; FLINT, CD (Elsevier BV, 1992-11-01) Scanning electron microscopy of particles of three bituminous coals (78.5% C, 81.7% C and 89.9% C d.a.f.) which had been treated with pyridine, methanol, bromine, air, sulfuric acid, ammonia and alkylating agents showed that the reagents produced significant changes in the morphology of the particles. The particles cracked and disintegrated in ways which appear to be characteristic of the disruption of hydrogen bonding, the volume and thermal changes accompanying local reactions and of the breakage of C-C b...
Hydrogen Generation from the Hydrolysis of Ammonia-borane and Sodium Borohydride Using Water-soluble Polymer-stabilized Cobalt(0) Nanoclusters Catalyst Metin, Onder; Özkar, Saim (American Chemical Society (ACS), 2009-07-01) Polymer-stabilized cobalt(0) nanoclusters were prepared from the reduction of cobalt(II) chloride in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) stabilizer in methanol solution. PVP-stabilized cobalt(0) nanoclusters were found to be stable in solution and Could be isolated its solid material and characterized by TEM, XPS, FT-IR, and UV-visible electronic absorption spectroscopy. PVP-stabilized cobalt(0) nanoclusters were employed as catalyst in the hydrolysis of sodium borohydride and ammonia-borane, ...

Citation Formats

M. AZIK, Y. YURUM, and A. GAINES, “AIR OXIDATION OF TURKISH BEYPAZARI LIGNITE .1. CHANGE OF STRUCTURAL CHARACTERISTICS IN OXIDATION REACTIONS AT 150-DEGREES-C,” ENERGY & FUELS, pp. 367–372, 1993, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/66816.