Solvation, coal

In contrast, the non-fusible coal requires the solvation (extraction) or solvolytic reaction to be liquefied. The solvation of non-polar organic compounds including the pitch may be rather limitted, so that the solvolytic reaction is necessary for the high liquefaction yield between the coal and the solvent. 

This approach is also applicable for the generalization of data concerning to the coal extraction under sub-critical conditions, but the role of the specific solvation is also insignificant, evidently as a result of its suppression at high temperatures. 

Dr. Sternberg We believe that it is the solvated lithium cation that is being reduced at the cathode to solvated zero charged lithium atom. The solvated lithium then reacts with the coal. This latter reaction may be homogeneous or heterogeneous depending on whether the coal molecule is solvated or not. 

Bhupendra K. Mazumdar Several papers relate to solubility or coal dispersion in different solvents and at different temperatures. Was any knowledge concerning the nature of linkage between the units of coal structure derived from these studies on the kinetics of solvation ... 

In thermal coal solvation, a reaction occurs between dissolved hydrogen (or hydrogenated solvent) and the fragmented coal molecules to produce a host of products. 

Thus, there appears to be something unique about the weakly acidic phenolic materials. In addition to phenol itself, 3,5-xylenol, 2-naphthol, phenol-naphthalene (1 1). and cresylic acid all show ability to solubilize the coal. Recently, Darlage and Bailey have studied the phenol catalyzed depolymerization of a Kentucky coal (Pond Creek Seam, Pike County). (16) This coal does not depolymerize efficiently and would compare with the poorest coals tested with data shown in Table II. These authors also show that phenolic solvents in general cause solvation of coal whereas non-phenolic aromatics add to coal but do not solubilize the coal. 

For the reaction to occur both phenol and a solvated proton must diffuse into the coal to reach an aromatic methylene bond. Phenol is a better solvent for bituminous coals than is pyridine (28) and is expected to interact strongly with coal and probably swell it. The penetration of coal by phenol at its boiling point should be rapid and extensive. However, the proton has little affinity for a hydrocarbon environment, and its diffusion into the hydrophobic coal is not expected to be facile. The way in which the solvation of the proton will affect its diffusion in coals is unknown. As a result of limitations on proton transport, this reaction may be subject to accessibility limitations. 

The problem of solvation of dextrins is still unsolved in general. It was documented that even such commonly used solvents as ethanol exhibit an unusually strong interaction with dextrin, as determined by H-n.m.r. spectroscopy. The interaction of dextrin with normal alcohols from methanol to 1 -hexanol was studied by determination of their infinite-dilution activity-coefficients in dextrin - water mixtures. " Studies carried out on the adsorption of dextrin on oxidized coal revealed that hydrophobic moieties in dextrin are involved in that process. The possibility of hydrophobic bonding has made dextrin an interesting component of the media used for flotation. Dextrin acts as a flocculant (depressant). When combined with a proper additive providing action by means of hydrogen bonding, reverse flotation... 

Consequently, the vast majority of SCF applications are based on CO2 near the GL critical point, with a possible admixture to support the ability for solvating dipolar components. The extraction of carcinogenic aromatic hydrocarbons and their nitro derivatives from diesel particulates by CO2 + toluene or methanol SCF can serve as an example. CO2 based SCF also helps in cleaning polyethylene from undesired polymer additives. In a similar way one can consider technologies focused on so called h q)er-coal, an extremely pure and environment friendly fuel for turbines in power plants. Recently, the first power plants based on this idea are being constructed in China. The removal of pesticides from meat, decaffeinated coffee and denicotinized cigarettes are the next society-relevant applications. Noteworthy is the h q)er-oxidation with supercritical water and bitumens extraction based on supercritical toluene. The latter system is also used for the liquefaction of coal. ... 

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