A comparative study on structural differences of xylite and matrix lignite lithotypes by means of FT-IR, XRD, SEM and TGA analyses: An example from the Neogene Greek lignite deposits

Beneficiation of Indian coals using Ionic Liquids

“…Some of the acceptor group solvent such as pyridine provides strong hydrogen bonding to swell the coal particles. However, they also fractionate a lesser amount of these hydroxyl groups [9][10][11][12][13][14]. Pseudo solvents such as pyridine and tetracyanoethylene also gave comparable results for coal fractionation.…”

“…6-9. The details of characteristic peaks and their functional groups used in this work are available elsewhere [10][11][12][13]. The prime objective concerning the dissolution and swelling of the coal particles are due to the breakage of the hydrogen bonding network as outlined in the earlier section.…”

“…The groups are more pronounced for liquefaction process where the interaction of cross-linking of coal surface and solvents play a vital role [4][5][6][7][8]. Low-rank lignite, sub-bituminous and low-volatile bituminous coals are polar in nature and posses oxygencontaining functional groups [9][10][11][12][13][14]. These oxygen-containing functional groups lower the carbon content and thus its calorific value.…”

Comparative studies on the effect of mineral matter on physico-chemical properties, inherent moisture and drying kinetics of Chinese lignite

“…For temperature between 100°C and 300°C, it could be inferred that inherent water was the major product that was released. As temperature further increased, both TG curves revealed continuous weight loss during heating up to $600°C, which was mainly due to burning of the organic compounds (FTIR results) [41]. Furthermore, the TG observations were corroborated by the DTA analyses.…”

Catalytic characteristics of the pyrolysis of lignite over oil shale chars

“…The band at $1033 cm À1 illustrated in Fig. 1(c) is attributed to CAOAH bonds in cellulose as well as to CAO stretching vibrations of aliphatic ethers (RAOAŔ ) and alcohols (RAOH) whereas the $1104 cm À1 and $1030 cm À1 bands arisen from the SiAO apical and SiAOASi stretching vibrations of the enclosing mineral matter respectively [32]. The band at $531 cm À1 originated from SiAOAAl VI vibrations (Al in octahedral co-ordination), whereas the band at $469 cm À1 is attributed to the SiAOASi bending vibrations and $426 À1 to FeS 2 .…”