On kieselguhr catalyst

Isopropylnaphthalenes can be prepared readily by the catalytic alkylation of naphthalene with propjiene. 2-lsopropylnaphthalene [2027-17-0] is an important intermediate used in the manufacture of 2-naphthol (see Naphthalenederivatives). The alkylation of naphthalene with propjiene, preferably in an inert solvent at 40—100°C with an aluminum chloride, hydrogen fluoride, or boron trifluoride—phosphoric acid catalyst, gives 90—95% wt % 2-isopropylnaphthalene however, a considerable amount of polyalkylate also is produced. Preferably, the propylation of naphthalene is carried out in the vapor phase in a continuous manner, over a phosphoric acid on kieselguhr catalyst under pressure at ca 220—250°C. The alkylate, which is low in di- and polyisopropylnaphthalenes, then is isomerized by recycling over the same catalyst at 240°C or by using aluminum chloride catalyst at 80°C. After distillation, a product containing >90 wt % 2-isopropylnaphthalene is obtained (47). 

Arnett, R.L. and Buell, B.O. Magnetic separator for removing nickel-on-kieselguhr catalyst from conjugated diene solutions. US Patent (1956) 2,760,638. 

The catalysts used in these experiments included those already employed in the infrared measurements in addition to some others. The results are presented in Tables VI and VII along with some older measurements on Raney-nickel and a nickel-on-kieselguhr catalyst. These older measurements are slightly less accurate because the cyclohexane content of the reaction product was determined by mass spectrometry. The surface area of catalyst E was not determined hence, its reaction rates per unit of surface area could not be calculated. 

Wright and Brandner84 have shown the reversible interconversion of aqueous solutions of these three dianhydrides in the presence of a nickel-on-kieselguhr catalyst under hydrogenating conditions. At the steady state, the product contains 57% of l,4 3,6-dianhydro-L-... 

Fig. i. Treatment of aromatic mineral oil fractions with nickel on kieselguhr catalysts and high pressure hydrogen. 

With a DELOXAN supported palladium complex catalyst, DELOXAN HK I, the linoleate selectivity is further increased. In comparison to the commercial batch hydrogenation with a nickel on kieselguhr catalyst, the DELOXAN supported palladium complex catalyst in combination with sc CO2 as a solvent gives higher space-time-yields, a higher linoleate selectivity and a significantly decreased cis/trans isomerization rate. 

DELOXAN AP II supported platinum catalysts in sc CO2 are less active than DELOXAN AP II supported palladium catalysts, but they show an improved linoleate selectivity and a significantly lower cis-trans isomerization rate. The overall yield of undesirable trans fatty acids is 7.5 GC area-% in the edible oil hardening with a DELOXAN AP II supported 2 wt. % platinum catalyst. In a batch hydrogenation using the commercial powdered nickel on kieselguhr catalysts the undesirable trans fatty acid content was determinded to 40 percent. 

Hydroquinone is reduced by a nickel-on-kieselguhr catalyst to cis- and /ra is-l,4-cyclohexanediols. Other eyelohexanediols and meth-oxycyclohexanols are formed from dihydric phenols and their monomethyl ethers. /S-Naphthol may be reduced in either ring, depending upon the catalyst and conditions. ... 

Catalysts. The nictel-on-kieselguhr catalyst used in initial work was the commercially available Harshaw-0101 T. This catalyst was crushed and sieved to —6/+20 mesh for fixed bed studies. Three nickel-alumina... 

A nickel-on-kieselguhr catalyst containing about 70% of nickel in the reduced form, similar to the catalyst used by Haensel, was employed in the initial work. Since the removal of the methyl group from methylcyclohexane is considerably more difficult than removal of an unbranched methyl from a paraffin, the catalyst was pretreated for maximum activity by reducing in a stream of hydrogen for 15 hours at 700°F. 

Evaluation of commercial catalysts showed that nickel-on-kieselguhr catalyst is more active than nickel-on-alumina, iron, and ruthenium catalysts for cleanup of CO in IGTs hydrogasification process. Longer chained hydrocarbon formation is much less than expected for tests with iron and ruthenium catalysts. 

The nickel-on-kieselguhr catalyst was from the same lot as used by H. S. Taylor for his catalytic researches. The 0.3 % palladium on silica gel and... 

The effect of the temperature on the course of the ethylene-deuterium reaction at half atmospheric pressure was studied at —78, —50, 0, and 110°, and the results are presented in Table II for a nickel-on-kieselguhr catalyst. It is seen that the deuterium gas is free of protium up to 0° and contained 36% hydrogen at 110°. The ethylene fraction was free of deuteroethylenes at —78 and —50° but contained appreciable amounts at 110°. A redistribution of the deuterium among the various deuteroethanes was noted at —78° and a trend toward the more heavily deuterated compounds as the temperature was raised. 

Until 1932, Raney nickel was considered only as a very active hydrogenation catalyst for the hydrogenation of vegetable oils. However, in the October 1932 issue of the Journal of the American Chemical Society, Professor Homer Adkins (13) of the University of Wisconsin announced to the scientific community that a new nickel catalyst "preferable to the nickel on Kieselguhr catalyst" was available from Murray Raney of... 

CHij will give essentially the same reaction as SiHij, but the temperature required is 750 to 800°C, whereas other alkanes react at slightly lower temperatures (331). Some success has been achieved with certain other organic compounds at still lower temperatures, as with decomposing aldehydes and ketones and BCI3 or BBr3 in the presence of various catalysts. A 70% conversion to diborane is claimed for mixtures of the tribromide and formaldehyde when passed over a copper-on-kieselguhr catalyst at 400°C (122). 

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