The production of potassium hydroxide

Potassium hydroxide is considerably more expensive than sodium hydroxide because the feedstock is refrned, crystalline, potassium chloride. It is only used when it has a particular advantage, and the production of potassium hydroxide is only 2-3% that the sodium hydroxide. Potassium hydroxide can be produced 

Man tell, C. L. I960) Electrochemical Engineering, McGraw-Hill, New York. 

Schmidt, A. ( 916)Angewandte Elektrochemie, Verlag Chemie, Weinheim. 

(1911) Industrial Electrochemical Processes, Elsevier, London. 

Coulter, M. ( 9%Qi)Modern Chlor-Alkali Technology, Ellis Horwood, Chichester. 

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The production of sodium hydroxide by electrolysis has been described in sufficient detail, and this procedure serves equally well for the production of potassium hydroxide. 

The ratio of values Wt and W in percents indicates the total energy (power) efficiency of the electrolysis. The efficiency of the production of potassium hydroxide is calculated analogously. 

A smaller quantity of activated carbon is used for separation of organic impurities from solutions in the production of potassium hydroxide, alums, and soda ash in order to obtain high quality products. Activated carbon filters are also lied for the purification of ram-... 

Production. Today, potassium hydroxide is manufactured almost exclusively by potassium chloride electrolysis. The diaphragm, mercury, and membrane processes are all suitable for the production of potassium hydroxide, but the mercury process is preferred because it yields a chemically pure 50 % potassium hydroxide solution. 

Chlorine from Potassium Hydroxide Manufacture. One of the coproducts during the electrolytic production of potassium hydroxide employing mercury and membrane ceHs is chlorine. The combined name plate capacity for caustic potash during 1988 totaled 325,000 t/yr and growth of U.S. demand was expected to be steady at 2% through 1990 (68). 

Benzotriazole (HL) with Me SAuCl in alkaline medium gives the polymeric [AuL] (79IC658). Another synthetic approach is based on interaction of benzotriazole with PhjPAuCl in the presence of potassium hydroxide, which yields first PhjPAuL and then the decomposition product [AuL]. ... 

A sample of this product was hydrolyzed in a mixture of water and methanol In the presence of potassium hydroxide. Essentially pure methotrexate was thus obtained. 

Treatment of a solution of 2-benzothiazolylthioacetyl hydrazide 386 in ethanol with carbon disulfide in the presence of potassium hydroxide gives the rearrangement product [l,2,4]triazolo[3,4- ]benzothiazole-3-thiol 387 (unreported yield) (Scheme 43). The structure of this compound was confirmed by its analytical and spectroscopic data, and confirmed by unequivocal synthesis from 2-benzothiazolhydrazine 388 under the same experimental conditions <2002MI3, 2002MI4>. 

The general feature of alkylation reactions at a carbon atom is that they can be achieved under sonication using solid bases even in apolar solvents. The advantage is that side reactions are generally minimised. Deprotonation occurs readily on a benzylic position in the presence of aqueous sodium hydroxide, as shown with indene (Eq. 3.21) [117]. A quantitative yield of the alkylated product can be obtained using sonication in the presence of a PTC. It was suggested that alkylation of cyclopentadiene or indene by secondary or tertiary alkyl halides in the presence of potassium hydroxide and Ali-quat occurred via a SET process [118]. 

Vinyl glycosides are difficult to prepare by conventional vinylation procedures although it has been reported that 2,3 5,6-di-0-isopropyl-idene-D-mannofuranose with acetylene in the presence of potassium hydroxide afforded vinyl mannosides A much better transvinylation procedure was used by Fletcher and coworkers as shown in Scheme 12 to give mixed products which, after chromatographic separation, were converted to vinyl a- and p-D-glucopyranosides by treatment with sodium in liquid ammonia... 

G. F. Schonbein, as previously indicated, found that when iodine water is mixed with potassium hydroxide, the analogy of the product with soln. of the hypo-bromites and hypochlorites shows that potassium hypoiodite is in all probability formed by a reversible reaction, 2KOH +I2 KI +KOI+H20, and that, when in equilibrium, the addition of potassium iodide will reverse the reaction, forming free iodine and potassium hydroxide. Hence, (i) the amount of potassium hydroxide required to complete the reaction must be greater than is indicated by the equation, as was found to be the case by R. L. Taylor and (ii) the failure of many to obtain evidence of bleaching soln. of hypoiodite when soln. of iodine in potassium iodide are employed. If a large excess of potassium iodide is present, this will prevent... 

Synthesis. Deoxybenzoin is converted to the corresponding oxime by treatment with hydroxylamine under basic conditions with sodium acetate in aqueous ethanol or in toluene in the presence of potassium hydroxide in absolute ethanol. Treatment of the oxime under nitrogen with two equivalents of butyllithium in tetrahydrofurane is followed by cyclization in ethyl acetate or acetic anhydride to the isoxazoline derivative. Finally, treatment of the isoxazoline with cold chlorosulfonic acid followed by reaction of the intermediate with aqueous ammonia affords the desired product. (Talley, 2000a Sorbera, 2001b). 

The aldehydes and ketones formed in this reaction are subject tn secondary oooden ation reactions, and so the isolation of product nor molly is difficult. However, the reaction of potassium hydroxide in... 

The product of the action of potassium hydroxids on the bromide he assumed to be the anhydride of acetopropyl alcohol,but it Is in reality acetylcyclopropane,as Perxli showed4. The formation of Lipp s bromide is no. to be represented by the above reaction but is rather formed by the splitting of his acetylcyclopropane-l-acid by the concentrated acid hi used in acidifying and also from methyldehydropentone-carboxylic acid (a by-product). 

Thus, for example,36 reaction of Schiff s base from 3-formyldibenzo-furan and p-chloroaniline with 4-methylstilbene and with 4-methyltolan in the presence of potassium hydroxide results in the formation of products 50 and 51, respectively. 

Schiff s base from 2-formylpyridine and /7-chloroaniline (194) yields in the presence of potassium hydroxide at room temperature, among other products, l,2-di(/ -chloroanilino)-l,2-di(2-pyridyl)ethene (195) and the corresponding alkane (196).34 This dimerization reaction has been... 

The 2-benzazepin-3-ones 259 have been made in moderate yields by sequential intramolecular acid-catalyzed addition followed by thiol elimination from the precursor phenylsulfanylacrylamides 258 (Scheme 33). The acrylamides 258 were prepared from reaction of the benzylamines 255 with the PNB-ester 256 to give the amides 257, and then N-methylation with Mel in the presence of potassium hydroxide and tetraethylammonium bromide, as a phase-transfer catalyst. Other noncyclized products were also observed depending on the structure of the A-aryl methyl group in 258 and on the nature of the solvent <2002H(57)1063>. 

Potash is used as a collective name for mined or produced salts that contain water-soluble potassium (for a large part as sylvite, potassium chloride mineral), with a total worldwide production of 35 Mt in 2007 [1]. Potassium (bi)carbonate production methods involve the carbonation of potassium hydroxide (KOH), which in turn is produced by electrolysis of aqueous potassium chloride solutions. 

When tetrahydropyridopyrimidine-3-carboxylate 562 (R = COOEt, R1 = H) was treated with carbon disulfide in the presence of potassium hydroxide at 25-30°C, salt 569 was obtained in good yield (79NEP79/ 3401 82USP4321377). The alkylation of569 with dimethyl sulfate and with ethylene dibromide in ethanol afforded 9-dithioester 570 and 9-(dithiolen-2-ylidene) derivative 571, respectively. When 569 was heated in acetic anhydride for 2 hours, bis product 572 was obtained in 57% yield. 9-Imidazolidine derivative 573 was prepared from both iminium chloride 563 (R = COOEt, R1 = H, R2 = Me) and 9-dithioester 570 by treatment with ethylenediamine (Scheme 37) (79NEP79/3401 82USP4321377 83MIP1). 

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