Liquid product, centrifuged

Coal Products Isotopic Distribution by Structural Position. Other workers have also investigated deuterium uptake in coal pro-ducts by structural position. Schweighardt, et al. (26) examined a centrifuged liquid product from a Synthoil run which was heated to 450°C with deuterium gas, Kershaw and Barrass (27) examined the products from the reaction of coal with deuterium gas using SnCl2 as catalyst, and Franz (10) examined the products from the reaction of a subbituminous coal with Tetralin-1,l-d2 at 427°C and 500°C. 

TABLE III.- Analyses of centrifuged liquid product samples... 

Figure 2. Fractionation scheme for centrifuged liquid product (CLP)...

The increase in viscosity of the product oil during a run is due primarily to an increase in asphaltenes and possibly pyridine sols content and not to a change in the molecular weight of the asphaltenes or to an increase in the viscosity of the heavy oil. This may be seen by comparing batches 7 and 88 of run FB-40 in tables VII and VIII. The viscosity of the centrifuged liquid product increases from 59 to 1,433 with an increase in asphaltene content from 22 to 40 and an increase in pyridine sols content from 2 to 5. In contrast, the viscosity of the heavy oil increases only from 12 to 17. There is no increase but rather a slight decrease in the molecular weight of asphaltenes from 459 to 416. 

The increase in viscosity of centrifuged liquid product with asphaltene content is shown in figure 4, where viscosities for runs FB-39 and FB-40 are plotted against asphaltene content. 

Ireland Mine hvAb coal was used in the coal pyrolysis studies. The method of heat treatment was essentially that reported by Petrakis and Grandy (8), Ireland Mine coal was also the feed coal used to obtain most of the coal liquefaction products. The coal-derived liquids investigated were centrifuged liquid products (CLP) and their subfractions from selected runs in the Pittsburgh Energy Technology Center s 400-lb coal/day coal liquefaction process development unit (PDU) (9). 

The liquid products were collected in 4-hour batches, centrifuged, sampled, and analyzed for asphaltene, oil, elementary composition (C, H, N, S), ash, specific gravity, and viscosity. 

The liquid product from the lOO C reactor is countercurrently stripped with 90 C air to remove nitrogen oxide gases. The more volatile oxidation by-products such as valeric and butyric acids are removed by steam distillation and the liquors concentrated for adipic acid recovery. Adipic acid is crystallised from the liquors at about 40-50 C and is recovered by centrifugal separation. Mother liquor is then recycled to the process. Two-step crystallization may be used to improve recovery and reduce the proportion of succinic acid impurity in the recycle. 

Small Scale Reactions When the reaction mixture occupies a few milliliters, the reaction can be carried out in a tapered centrifuge tube to facilitate recovery of a solid or liquid product after removal of solvent. On a still smaller scale, sections of small glass tubing sealed at one end are often used, and the course of the reaction may be followed by a spectral technique. For example, if an exploratory reaction can be conveniently followed by nuclear magnetic resonance (NMR) spectroscopy (Sec. 3.3.1), the reaction can be performed in an NMR sample tube and its progress checked periodically by NMR. 

The products were usually separated into light oils, middle distillates, and residuum. The residuum fraction was filtered (or centrifuged) to ranove any solid material (unreacted coal, mineral matter, and ash) and the remaining material was nsed as a recycle oil for the liquefaction stage. The lighter liquid products were generally hydrotreated to produce stable liquid fuels. 

In the first commercial plant (20,000 t/a), a cascade of stirred tank reactors are operated at 170°C between 10 and 17 bar. The catalyst (palladium supported on charcoal) is separated from the liquid product by centrifugation. Small amounts of catalyst are recovered at the bottom of the cyclohexanoe carboxylic acid distillation column. A plant of 100,000 t/a capacity is no in operation. 

Nonwoven Adult Incontinence Products Centrifugal Liquid Retention Capacity Test (Dry Weight vs Wet Spun Weight) (NWSP 070.10.R1 (15))... 

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