摘要:
A method for preparing an alkylbenzoic acid is herein disclosed which comprises subjecting an alkylbenzene having at least two alkyl groups of 1 to 3 carbon atoms to a liquid phase oxidative reaction with a molecular oxygen-containing gas in the presence of a soluble heavy metal catalyst to convert one alkyl group into a carboxylic acid, thereby preparing the alkylbenzoic acid, and impurities contained in the alkylbenzene recovered from the reaction solution are removed therefrom by distillation, water washing, alkali washing, a treatment with an anion exchange resin or a treatment with a solid adsorbent, and the impurities-free fraction is reused as a raw material. Furthermore, the conversion of the desired product is regulated to 25% or less in the liquid phase oxidative reaction, whereby the reaction is carried out in a boiling heat removal state and reaction heat is removed as the heat of vaporization. Thus, there can be decreased a dicarboxylic acid secondarily produced during the manufacture of the alkyl-benzoic acid which is a monocarboxylic acid by subjecting the alkylbenzene to the liquid phase oxidation, whereby problems such as the trouble of equipment operation and the deterioration of product quality can be solved.
摘要:
A tertiary olefin is produced by contacting a gaseous tertiary ether usually represented by the following general formula: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are alkyl groups each having 1-4 carbon atoms which may be same or different and R.sup.4 is an alkyl group having 1-3 carbon atoms, with a catalyst obtained by calcining a silica-alumina compound at 700.degree.-1100.degree. C. in order to effect cracking of the tertiary ether. This reaction may be carried out in the presence of steam to result in further improvements.
摘要:
Disclosed is a process for the preparation of tertiary olefins which comprises catalytically decomposing a tertiary ether to a tertiary olefin, wherein the catalytic decomposition of the tertiary olefin is carried out in the presence of a solid phosphoric acid catalyst which has been calcined at a temperature of at least 500.degree. C. in an inert gas.
摘要:
In an assembly line in which at least two kinds of workpieces are transported by mixture and in which each of the workpieces is transported by a self-propelling transporting member, a transporting pitch for each kind of workpiece is set in advance based on a difference in the number of assembling man-hours required for each of them. The timing for starting the transporting member off a starting end of the assembly line is controlled according to the transporting pitch such that a pitch between a preceding transporting member and a succeeding transporting member becomes equal to that which is set for a workpiece to be transported by the preceding transporting member.
摘要:
An aromatic primary hydroperoxide is produced by oxidizing a methyl-substituted aromatic compound in a liquid phase with a molecular oxygen-containing gas at a temperature of 80.degree.-150.degree. C. under a pressure of the atmospheric to 100 kg/cm.sup.2 gage in the presence of 8-300 parts by weight of an aliphatic tertiary hydroperoxide per 100 parts by weight of the methyl-substituted aromatic compound. The oxidation reaction is promoted, an aromatic primary hydroperoxide content of the reaction products is increased, whereas by-products are reduced, and a selectivity to the aromatic primary hydroperoxide is considerably increased.
摘要:
A method of producing methyl methacrylate comprises Step 1 of producing acetone cyanhydrin from hydrogen cyanide and acetone; Step 2 of producing .alpha.-hydroxyisobutyramide by hydrating acetone cyanhydrin; Step 3 of producing methyl .alpha.-hydroxyisobutyrate and ammonia by a reaction of .alpha.-hydroxyisobutyramide and methanol; Step 4 of producing methyl methacrylate by dehydrating methyl .alpha.-hydroxyisobutyrate; and Step 5 of producing hydrogen cyanide in vapor phase by reacting methanol and the ammonia obtained in Step 3 over a solid catalyst in the presence of molecular oxygen. By using methanol in the step 3, the conversion ratio of .alpha.-hydroxyisobutyramide into methyl .alpha.-hydroxyisobutyrate can be increased because the equilibrium of the reaction is easily sifted toward the product side by removing ammonia being produced from the reaction system. The use of methanol in the step 3 produces additional advantages of efficiently linking the steps to eliminate the steps for separation and purification, thereby reducing the production cost.Step 1:HCN+CH.sub.3 COCH.sub.3 .fwdarw.(CH.sub.3).sub.2 (OH)CN;Step 2:(CH.sub.3).sub.2 C(OH)CN+H.sub.2 O.fwdarw.(CH.sub.3).sub.2 (OH)CONH.sub.2Step 3:(CH.sub.3).sub.2 C(OH)CONH.sub.2 +CH.sub.3 OH.fwdarw.(CH.sub.3).sub.2 (OH)CO.sub.2 CH.sub.3 +NH.sub.3Step 4:(CH.sub.3).sub.2 C(OH)CO.sub.2 CH.sub.3 .fwdarw.(CH.sub.2).sub.2 .dbd.C(CH.sub.3)CO.sub.2 CH.sub.3 +H.sub.2 OStep 5:CH.sub.3 OH+NH.sub.3 +O.sub.2 .fwdarw.HCN+3H.sub.2 O
摘要:
A process for producing a 4-formyl-4'-methylbiphenyl from a biphenyl which comprises conducting the carbonylation of the biphenyl with carbon monoxide in the presence of a HF-BF.sub.3 catalyst in a carbonylation reactor to obtain the resulting reaction product solution containing a 4-formylbiphenyl, separating the 4-formylbiphenyl from the reaction product solution, hydrogenating the separated 4-formylbiphenyl to obtain a 4-methylbiphenyl, recycling the 4-methylbiphenyl to the carbonylation reactor, and then conducting both the carbonylation of the biphenyl with carbon monoxide to obtain a formylbiphenyl and the carbonylation of the 4-methylbiphenyl with carbon monoxide to obtain a 4-formyl-4'-methylbiphenyl simultaneously in the presence of the HF-BF.sub.3 catalyst in the carbonylation reactor.
摘要:
Carboxylic acid esters and formamide are efficiently obtained by reacting carboxylic acid amides and formic acid esters, or by reacting carboxylic acid amides, alcohols and carbon monoxide in the presence of a dehydrated condensate of carboxylic acid amide with an alkali metal hydroxide or an alkaline earth metal hydroxide catalyst.
摘要:
A commercially economical process for preparing a carboxylic acid ester from a carboxylic acid amide is disclosed. The process is very meritorious, since it produces neither ammonia nor ammonium sulfates. Rather, the process by-produces formamides which are very useful compounds as solvents. Further, formamide can easily be converted to hydrogen cyanide by dehydration. The process comprises reacting a carboxylic acid amide with a formic acid ester and/or methanol and carbon monoxide in the presence of a bicyclic amidine or tertiary amine catalyst and optionally in the co-existence of a metal carbonyl. An industrial process for preparing methyl methacrylate which is a materialization of the process shown above is described in detail referring to a figure.
摘要:
A tertiary olefin is produced by making a gaseous tertiary ether usually represented by the following general formula: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are alkyl groups each having 1-4 carbon atoms which may be same or different each other and R.sup.4 is an alkyl group having 1-3 carbon atoms, contact a catalyst obtained by calcining a silica-alumina compound at 700.degree.-1100.degree. C. in order to carry out cracking of the tertiary ether.