Potassium carbonate alkalizer

In all cases there is preliminary alkalization of the iron with about 0.5-1.5% alkali necessary. Potassium carbonate is generally used. Some patents, however, mention special treatment of the ores, for example with potassium fluoride (68). 

Currently, most cocoa powders are produced by the so-called Dutch or alkalized process, in which the nib is treated with a warm aqueous solution of up to three parts of anhydrous potassium carbonate to 100 parts of nib (or equivalent amounts of other alkalis such as potassium bicarbonate and hydroxide carbonates, bicarbonates, and hydroxides of sodium, magnesium, and ammonium or their combinations). After the alkali is completely absorbed, the nib is processed as in the above method to yield alkalized cocoa powder. Alkalized cocoa is considered to have improved dispersibility, color, and flavor over unalkalized cocoa. 

Procedure Symmetrical diethyldiphenylurea (0.2 g) is heated carefully in a sealed tube for 6 hr at 200 °C with 2 ml of HCl. After opening the tube its contents are transferred into a separatory funnel and the tube is rinsed with 5 ml of water. The combined solutions are alkalized with 5 N NaOH and extracted three times with 10 ml of ether. The ethereal extracts are dried with anhydrous potassium carbonate and filtered into a distillation flask. Ether is evaporated and the residual oil (ethylaniline) is treated with 100 mg of 1-naphthylisothiocyanate, applying the procedure described on p. 339. Yield, 30 mg mp, 125-126 °C. 

Selective etherification of the 3-hydroxy group of 1,3-dihydroxy-lO-methyl-acridone (19) with excess bromoacetaldehyde diethylacetal in dry dimethylformamide, either by use of sodium hydride at 120"C in a bomb, or in the presence of potassium carbonate at 100°C under nitrogen, afforded 3-(2,2-diethoxyethoxy)- -hydroxy-10-methylacridone (314). Cyclodehydration of 314 by refluxing in a mixture of dioxane and dilute aqueous sulfuric acid, followed by alkalization by addition of sodium hydroxide and heating, gave the desired furacridone (26), accompanied by smaller amounts of the linear isomer, isofuracridone (315) 330). 

The most intensive bleaching action is achieved with paste bleaches, which are prepared before use by mixing hydrogen peroxide solution (6-12 vol%) with a bleach powder. The powder consists of a peroxodisulfate, an alkalizing agent, stabilizers, thickeners, and other additives. Sodium, potassium, or ammonium peroxodisulfate is used. The ammonium salt is most effective when combined with an alkalizing component such as sodium carbonate or silicate, ammonia is formed. 

Catalyst makers also succeeded in minimizing the activity reducing effect of the potassium in the alkalized catalysts [430], Pre-reduced primary reforming catalysts are now also marketed (ICI Katalco, Topsoe) [430], and splitloading of reformer tubes with more than one type of catalyst has now become very common. The benefitial effects concern pressure drop at increased plant load, carbon formation potential, catalyst activity, catalyst cost, and desired catalyst life. For example, a reformer tube may be loaded with 15 % alkali-free catalyst in pre-reduced form (top-section), 25 % unreduced alkali-promoted (middle section) and 60% alkali-free unreduced catalyst (bottom section). 

Sodium, potassium and calcium salts of mono and polyphosphoric acids, incl. such salts when alkalized with sodium carbonate, sodium hydroxide or sodium silicate... 

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