Quinoline insolubles carbonization

States or Australia. In some cases, pot stills, arranged in cascade, are still used. The more sophisticated plants employ one or more carbon steel or cast-iron vessels heated electrically and equipped with temperature controls for both the bulk Hquid and the vessel walls. Contact time is usually 6—10 h. However, modem pitches are vacuum-distilled, producing no secondary quinoline insolubles, to improve the rheological properties. 

Mesophase formation in coal-tar pitch is encouraged by a reduction of the natural quinoline-insoluble matter content, which resembles carbon black but is not optically anisotropic and is characterized by an atomic carbon hydrogen ratio of 4 1. In contrast, the atomic carbon hydrogen ratio of mesophase is about 2 1. 

Coal-tar pitches generally soften around 110°C, are about 70 wt% soluble in toluene and 12 wt% insoluble in quinoline. Excessive amounts of primary quinoline insolubles (QI) would contribute to increased carbon yield, but such a pitch may not wet coke well and could hinder the penetration of pitch mto the coke voids. 

Philip L. Walker, Jr. Dr. Taylor has been describing results for the carbonization of a coal tar pitch which was very low in quinoline insolubles (QI). In this case the mosaic unit which he finds in the cokes is quite large. I am wondering if he has looked at pitches of a higher QI content and if the mosaic size in the cokes decreases with increasing QI content in the original pitch ... 

The optical texture of mesophase and resultant carbons is observed readily by means of a reflected polarized light microscope and may be classified according to the shape and size of the isochromatic units. Such a classification is useful to evaluate the properties of mesophase and carbons such as needle cokes. The mesophase has been defined as the intermediate state which shows optical anisotropy and is quinoline-insoluble at room temperature (5,51) (liquid crystal glass), although it is a viscous liquid crystal during the carbonization process (6). ... 

A number of methods are used to evaluate a data set to describe the kinetics of carbonization, such as determining the temperature/time dependence of viscosity, quinoline insolubles formation, or weight loss ... 

The Effect of the Nature of Quinoline Insolubles on Electrode Pitch Binder Properties, Report 33, British Carbonization Research Association, Wingerworth, Derbyshire, November 1976. 

An Exxon cat cracker bottom pitch was extracted with solvents of varying solubility parameter in order to evaluate the relationships which exist between extraction conditions and the characteristics of the extracted product. The precursor pitch possessed a carbon/ hydrogen ratio of 1.49 and a alculatedO, overall average solubility parameter of 10.48 reflux quinoline insolubles content of the pitch was 2.3% and the refluxing toluene insolubles were at a level of 20.3%. The pitch was not optically anisotropic. Upon heating in N2 to 530 C in a TGA, a coke yield of 37% was obtained. 

The liquid phase carbonization process can be categorized on the basis of the starting material alkane hydrocarbon, alkene hydrocarbon, aromatic hydrocarbon, and PAH. Consequently, the primary material for MCMBs typically contains a large amount of PAHs from coal pitch and heavy oil. Components in primary materials, such as pyridine insolubles (Pis), quinoline insolubles (QIs), and other additives, and reaction conditions affect the growth, formation, and structure of MCMBs. 

The Great Lakes Carbon process uses coal-tar pitch as the precursor pitch. In this process, the quinoline insolubles are removed by extraction with light creosote oil. The low boiling constituents are then removed by stripping in vacuum. The residue, when heat soaked between 250 and 350 " C for 20 h, produces mesophase which can be spun into fibres at 287 °C. ... 

Petroleum pitch is used also for impregnating previously shaped refractories because petroleum pitch does not contain the quinoline insolubles that can block pores in the refractory body and limit the pitch penetration. In this manner, a carbon source can be added to formed refractories such as burned magnesia brick and, thus, enhance this brick s slag resistance. 

It is my contention that the optical and physical properties and the optical structure produced during the destructive distillation or thermal decomposition of vitrinite is closely related to mode of carbonization and, in the case of pitch, is intimately related to the method of pitch preparation. For instance, a pitch may be produced from a high or low temperature tar, from a primary cooler tar, or from a flushing liquor tar. In addition, it may be air blown, thermally or chemically treated, straight distilled, or cut back, just to mention a few. Under similar carbonization conditions almost any one of these pitches will produce a coke which has certain characteristics that are related to the parent pitch. Even pitches similarly processed from the tar can differ in the content of quinoline- and benzene-insoluble material and P-resin, and can contain more than one distinct liquid phase. None of these points of difference has been discussed by Dr. Taylor or even recognized in the preparation. To interpret the structure of pitch coke divorced from a knowledge of the pitch source and/or carbonization conditions can lead to erroneous conclusions. These are pertinent data omitted by the authors. 

Phenoxatellurin1 A mixture of 1.0 g (2.9 mmol) of 2-carboxyphenoxatellurin, a little copper-bronze, and 30 ml of dry quinoline is heated under reflux for 1 h. The mixture is cooled to 20° and poured into dilute acetic acid. The precipitate is filtered, washed with dilute acetic acid, then with water, and the solid is extracted with aqueous sodium carbonate solution. The insoluble material is recrystallized twice from light petroleum ether yield 0.2 g (23%) m.p. 77 19°. 

Quinoline-6-arsinic acid is prepared in a similar way to the preceding arsinic acid, 30 grams of 6-amino-quinoline jdelding 10 grams of the arsinic add. It crystallises with 1 molecule of water, melts at 260° to 262° C, and is readily soluble in alkalis, alkali carbonates, concentrated hydrochloric acid, and acetic acid, sparingly soluble in water and methyl alcohol. Reduction, as in the previous case, yields 6 Q -arsenoguinoline dihydrochloride in 80 per cent, yield, whicli is a yellowish-red amorphous product, insoluble in water and dilute acids, soluble in concentrated hydrochloric acid. 

Quinoline-8-arsinic add, obtained from 8-amino-quinoline in 83 per cent, yield, crystallises in white needles, M.pt. 230° C-, readily soluble in dilute alkali, sodium carbonate, and concentrated mineral acids, insoluble in dilute acids, alcohol, and cold water. When reduced... 

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