Sulfuric acid as catalyst

In a study of the kinetics of the reaction of 1-butanol with acetic acid at 0—120°C, an empirical equation was developed that permits estimation of the value of the rate constant with a deviation of 15.3% from the molar ratio of reactants, catalyst concentration, and temperature (30). This study was conducted usiag sulfuric acid as catalyst with a mole ratio of 1-butanol to acetic acid of 3 19.6, and a catalyst concentration of 0—0.14 wt %. 

Ethyl fumarate has been prepared from fumaric acid and ethyl alcohol, with or without sulfuric acid as catalyst,4 from silver fumarate and ethyl iodide,5 from silver maleate and ethyl iodide plus a trace of iodine,6 from ethyl maleate by the action of iodine,6 from ethyl maleate and phosphorus pentachloride,7 and by passing hydrogen chloride into a boiling absolute alcohol solution of malic acid.8... 

Polymer (184) has a network structure and was obtained by reaction of dibenzo-18-crown-6 with formaldehyde in formic acid. Amongst the alkali metal ions, it selectively captures K+ and Cs+ from methanol or methanol/water. A related polymeric product has been reported (as a gel) from the reaction of this crown with formaldehyde in chloroform using sulfuric acid as catalyst (Davydova, Baravanov, Apymova Prata, 1975). 

A mixture of 5 mol butanol per mol acetic acid flows to a tubular reactor at the rate of 45.4 kg/h or 10 liters/h at 100 C. It also contains 0.032 wt% sulfuric acid as catalyst. Inlet concentration of the acid is 1.744 gmol/liter. The rate equation (Leyes Ofchmer, 7nd Eng Chem 37 968, 1945) is... 

A combination of the thermal polymerization process and the U.O.P. catalytic process was introduced in 1937 at the Shamrock Oil and Gas Co., Sunray, Tex. (28). In 1934 the Shell Development Co. introduced the cold acid process (18), which selectively polymerizes isobutene, using sulfuric acid as catalyst. The hot acid process was also developed by them and differed from the cold acid process in polymerizing all C4 olefins. Both products are predominantly the dimer. The cold acid process produces a large pro-... 

Albright, L. F., Alkylation Processes Using Sulfuric Acid as Catalysts, ... 

The ethanoyl derivative of 2-hydroxybenzoic acid is better known as aspirin and is prepared from the acid with ethanoic anhydride, using sulfuric acid as catalyst ... 

A 500 kg batch had been prepared in glacial acetic acid using 35% aqueous hydrogen peroxide with 2% sulfuric acid as catalyst. When the reaction was complete, solvents were removed by vacuum distillation, steam was turned off and the reaction vessel... 

Paushkin and Topchiev also used H3P()4-BF3 at room temperature to alkylate benzene with olefins (287,402). For alkylation of benzene with alcohols, temperatures of 90-97° and a feed mole ratio of 0.5 alcohol 1.0 benzene 0.5 catalyst were recommended (394). In a recent study (400a) these authors supplemented their previously published views (396) concerning the properties of boron fluoride complexes with phosphoric acid, alcohols, and sulfuric acid as catalysts. Data on the electroconductivity of these catalysts was correlated with their activity in alkylation of isobutane and it was concluded (400a) that the acid ion concentration did not affect the alkylation or polymerization reactions over these catalysts, and therefore the carbonium ion mechanism was not applicable. 

Pretreatments such as filtration can have a direct impact on the quality of the final ester product, as well as on yields. Table 6.4 shows the effect on product quality of the ester from acid oil, which had been filtered to remove solids and other components. The filtered acid oil was pre-esterified under reflux with methanol (12 1 ratio MeOH to FFA) in the presence of 0.56wt% of 98% sulfuric acid as catalyst, based on the acid oil charge. The reaction was continued until the acid value was less than 5 mg KOH/g, followed by neutral-... 

Table 5.1. Compositions (mass%) of spent sulfuric acids from two chemical processes. Both processes use sulfuric acid as catalyst. The acid becomes contaminated with water, hydrocarbons, and other chemicals during use. It is made into new sulfuric acid as described in Fig. 5.1.

DISN adds to 2,2-dimethoxypropane in the presence of sulfuric acid as catalyst to give 2,2-dimethyl-4,5-dicyanoisoimidazole (9) in 80% yield. Reaction of (I) under oxalic acid catalysis also gives (9) in 80% yield. Reaction with acetone itself gives (9) in low... 

In Table 1.3.2 a method for the analysis of nitrates and nitrites for a wide variety of samples is given Aqueous nitrate ions are converted to nitrobenzene by reaction with benzene in the presence of concentrated sulfuric acid as catalyst. The special methods for the different materials are described. To stabilize samples against bacterial action, which can reduce nitrate concentrations, phenylmercuric acetate is added after collection ° Other inorganic compounds in the trace levels for gas-chromatographic determination are, for example, water and carbon monoxide, which were determined in organic solvents or air in the ppb-range ... 

ROH— RBr. The preferred procedure for the preparation of primary alkyl bromides calls for use of a small amount of sulfuric acid as catalyst. 2-Bromo-... 

Thiele reaction. BF,-etherate is more satisfactory than sulfuric acid as catalyst for the Thiele reaction of a-naphthoquinone, for with sulfuric acid the yield is only... 

Derivation Reaction of purified cellulose with acetic and butyric anhydrides, with sulfuric acid as catalyst and glacial acetic acid as solvent. The ratio of acetic to butyric components may be varied over a wide range. 

Derivation By esterification of phthalic anhydride with amyl alcohol in the presence of approximately 1% concentrated sulfuric acid as catalyst. 

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