Carbon suspensions

The carbon produced in the flame reaction, and which is subsequently removed as carbon suspension in water, amounts to 1.5 per cent by weight of the fuel oil feedstock charge. Some H2S present in the crude gas is removed by contact with the quench water. 

Add five 1-ml aliquots of the sodium borohydride solution to the chloroauric acid/ carbonate suspension with rapid stirring. A color change from bluish-purple to reddish-orange will be noted as the additions take place. 

Figure 5.3. Effect of concentration on the sedimentation of calcium carbonate suspensions...

Calcium Sulfite. (CAS 10257-55-31 CaSOj- 2H2O. white precipitate, pK = 7.9, formed by reaction of soluble calcium salt solution and sodium sulfite solution, or by boiling calcium hydrogen sulfite solution calcium hydrogen sullite. Ca(HSOj) . formed in solution by saturating calcium hydroxide nr carbonate suspension with sulfurous aeid. 

A similar effect can be seen following ocular administration of micronized carbon suspensions in perfluorodecalin. This vehicle is a nonsolvent and because the powder is delivered dry, the particles attach during the first reflexive blink and disperse to the lash roots (Figure 23.2) [2]. 

Quantitation of Napelline.—The pharmacological activity of napelline (35)38 has prompted the development of a method for the quantitation of this alkaloid in raw plant materials.39 This method consists of the extraction of the total alkaloids, chromatographic separation, and a micro-scale acid-base titration of the napelline eluate in a non-aqueous medium. The total alkaloids were exhaustively extracted from a sodium carbonate suspension with chloroform. This extract was concentrated, dissolved in acetone, and chromatographed on silica-gel plates, with a standard reference of napelline as a marker. The appropriate bands were quantitatively removed and extracted, and the extracts were concentrated to dryness. These residues were dissolved in glacial acetic acid and titrated with 0.01N perchloric acid. The standard deviation of this method was 3.39 x 10 3. No limits of detection are reported. 

Pt-C (by Kaffer).158 To 10-12 g of active carbon mixed well with water is added an aqueous solution of the calculated amount of chloroplatinic acid. The mixture is warmed on a water bath for a few hours at 50°C. After cooling, a concentrated sodium carbonate solution is added until the mixture becomes alkaline. Then a hydrazine hydrate solution is added drop by drop under stirring. Whether the amount of hydrazine is sufficient to reduce the chloroplatinic acid can be readily determined by the decoloration of a permanganate solution. The platinum-carbon suspension is further warmed for 1-2 h on a water bath, filtered, and washed with hot water until the washing is free from chloride and alkali. After dried as fully as possible between filterpapers, the catalyst is dried for half a day over calcium chloride in vacuum. Kaffer used a 10% Pt-C thus prepared for the dehydrogenation of decalin and found it much more effective than Pt-asbestos by Zelinsky. Newhall used a 5% Pt-C by Kaffer for... 

Cadmium carbonate suspension (freshly precipitated). To 20 ml of 0 5m cadmium acetate add 20 ml of 0 5m sodium carbonate solution. Allow the precipitate to settle and wash 4-5 times with water by decantation. 

An acyl chloride was used in the synthesis of the spermidine alkaloid cannabisativine (162) by Natsume and coworkers [92]. As shown in Scheme 53, the precursor 160 was hydrolyzed with Ba(OH)2 and the resulting amino acid was directly converted to acyl chloride HCl salt, a cold solution of which was added dropwise to a potassium carbonate suspension in acetonitrile to achieve the lactam closure. Deprotection of the methoxymethyl groups with acid afforded macrolactam 161 in 43% yield from 160. 

Tiongson A. Process of making an aqueous calcium carbonate suspension. International Patent WO 9945937 1999. 

The initial stages of brine pretreatment are quite similar for all three cell types except that the mercury and membrane cells have more stringent requirements. If calcium sulfate is present, its removal requires the addition of a barium carbonate suspension (Eq. 8.5). If calcium is present as the chloride, it is removed by the addition of sodium carbonate (Eq. 8.6). Magnesium ion... 

Babic et al. [2] report a CIP of charging curves (25°C, 0.001-0.1 mol dm KNO3) at pH 7, for self synthesized active carbon obtained from carbonized viscose rayon cloth. Seco et al. [3] titrated commercial activated carbon at four different ionic strengths and attempted to determine the equilibrium constants of reactions (5.32) and (5.33) from these titrations. Only results obtained at extreme pH values (<3 or > 11) were used, thus the apparent surface charge densities were obtained as differences of two large and almost equal numbers. On the other hand, at pH 4-10 the titration curve of carbon suspension and the blank curve were practically identical. 

Calcium carbonate suspension. Mix 1 g of CaC03 with 100 ml of water. 

Samarium phosphate was prepared by wet synthesis starting from samarium carbonate (Sm2(C03)3, originated RP). Precipitation of phosphate by phosphoric acid is conducted at 80°C by addition of a samarium carbonate suspension in a vessel containing phosphoric acid. After the end of the addition, the solid could be treated by ammonia at pH = 9. Cesium hydrogenophosphate is introduced by wetness impregnation of the dried (110°C) solid. 

Catalytic oxidation of vicinal diols to a-hydroxy carboxylates was performed by Prati and Rossi [82] in alkaline aqueous solution with gold-based catalysts prepared by deposition-precipitation with sodium carbonate from HAUCI4 solutions on active carbon suspension. The 1 % Au/C catalysts had remarkable properties compared with conventional Pt/C and Pd/C catalysts in terms of selectivity and stability. Thus, Table 1 shows that at pH 8,1,2-propanediol was very selectively oxidized to lactic acid, which indicates that gold was more selective than platinum and palladium in the oxidation of the primary alcohol function. The activity of gold catalysts was also very stable as a function of conversion or after several recycles, indicating that gold is less sensitive to over-oxidation and/or self-poisoning than platinum and palladium. 

On the other hand adsorbed hydrogen in the presence of water forms hydrogen ions which can be exchanged for other cations. The reaction is reversed by making the carbon suspension definitely acid, in which case, hydrogen is evolved as a gas. 

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