摘要:
A platinum-on-graphite catalyst having a platinum content of from 0.01 to 5% w/w, wherein the graphite support has an apparent density of from 1.7 to 2.2 g/ml and the use thereof as a hydrogenation catalyst.
摘要:
A platinum-on-graphite catalyst having a platinum content of from 0.01 to 5% w/w, wherein the graphite support has a particle size of from 1 to 600 .mu.m and the following particle size distribution:______________________________________ 183 to 600 .mu.m 15% v/v .+-. 15% absolute 68.3 to 183 .mu.m 30% v/v .+-. 20% 31.0 to 68.3 .mu.m 25% v/v .+-. 20% 17.1 to 31.0 .mu.m 15% v/v .+-. 10% 5.2 to 17.1 .mu.m 12% v/v .+-. 10% .sup.
摘要翻译:铂含量为0.01〜5%w / w的铂 - 石墨催化剂,其中石墨载体的粒度为1〜600μm,粒径分布为:183〜600μm15 %v / v +/- 15%绝对值-68.3至183μm30%v / v +/- 20%-31.0至68.3μm25%v / v +/- 20%-17.1至31.0μm15% v / v +/- 10% - 5.2至17.1μm12%v / v +/- 10% - <5.2μm5%v / v +/- 5%。 -
摘要:
Crystalline hydroxylammonium sulfate is prepared by a process which comprises the following steps:(a) Bringing an aqueous solution which contains from 0.02 to 0.3 part by weight of ammonium sulfate and from 0.02 to 0.2 part by weight of sulfuric acid per part by weight of hydroxylammonium sulfate into contact with a basic ion exchanger and obtaining a solution which has a pH of from 3.0 to 4.0,(b) separating off the basic ion exchanger from the aqueous hydroxylammonium sulfate solution,(c) evaporating down the resulting aqueous hydroxylammonium sulfate solution under reduced pressure at
摘要:
A process of use of hydrogenation catalyst, obtainable by carrying out essentially the following steps:(a) treatment of a platinum metal salt with finely divided sulfur followed by(b) reduction of the platinum metal salt to metallic platinum metal.
摘要:
A hydrogenation catalyst, obtainable by carrying out essentially the following steps:(a) treatment of a platinum metal salt with finely divided sulfur followed by(b) reduction of the platinum metal salt to metallic platinum metal.
摘要:
A hydrogenation catalyst, obtainable by carrying out essentially the following steps:(a) treatment of a platinum metal salt with finely divided sulfur followed by(b) reduction of the platinum metal salt to metallic platinum metal.
摘要:
Caprolactam is recovered from oligomers and/or polymers of caprolactam by cleavage of oligomers and/or polymers of caprolactam and subsequent working up by distillation of the caprolactam obtained in the cleavage, by a process including (a) cleaving oligomers and/or polymers of caprolactam to obtain an aqueous reaction mixture which contains caprolactam, (b) removing water from the reaction mixture obtained under (a) to obtain a residue, (c) distilling the residue obtained under (b) in an acidic medium and (d) then distilling the distillate in an alkaline medium to obtain caprolactam, or (c') distilling the residue obtained under (b) in an alkaline medium and (d') then distilling the distillate in an acidic medium to obtain caprolactam.
摘要:
Caprolactam is recovered from polycaprolactam by hydrolyric cleavage of polycaprolactam with from 5 to 50 parts by weight of water per part by weight of polycaprolactam at from 200.degree. to 350.degree. C. under superatmospheric pressure to give an aqueous solution or suspension which contains monomeric caprolactam and oligomers thereof and may contain polycaprolactam and subsequent isolation of monomeric caprolactam from the aqueous solution or suspension by distillation or extraction, by a process in which the hydrolyric cleavage is carried out in the presence of an alkali metal hydroxide at a pH of from 5 to 10.
摘要:
A process for working up aqueous mother liquors containing hydrochloric acid, sulfuric acid and their hydroxylammonium and ammonium salts, entails the mother liquors being intimately mixed with an excess of cyclohexanone based on the content of hydroxylammonium salts, while maintaining a pH of from 3 to 5.5 by adding alkali metal hydroxide solutions, and the cyclohexanone phase which contains cyclohexanone oxime being removed and washed with water until essentially free of chloride.
摘要:
Caprolactam is recovered from caprolactam distillation low boilers or high boilers or mixtures thereof by the following steps:(a) crystallizing a low or high boiler or a mixture thereof to form purified capro-lactam crystals and a mother liquor,(b) separating off the purified caprolactam crystals to leave a mother liquor,(c) recycling from 5 to 90% by weight of the mother liquor of stage (b) into stage (a) and transferring the remainder of the mother liquor into the subsequent stage (d),(d) crystallizing the remaining mother liquor portion from stage (c) to form caprolactam crystals and a mother liquor, separating off the caprolactam crystals of stage(e) (d) and recycling the same into stage (a) to leave a mother liquor,(f) recycling from 20 to 99% by weight of mother liquor of stage (e) into stage (d) and channeling out the remainder of the impurity-containing mother liquor of stage (e).