Allan L. Odell

A system of standard retention indices and its uses the characterisation of stationary phases and the prediction of retention indices

Abstract A method for the calculation of “standard” retention indices from boiling point data has been proposed. The uses of standard retention indices and standard retention index differences for the characterisation of stationary phases and the prediction of retention indices on any stationary phase at any temperature have been discussed. A “cyclic” effect on retention data has been found on squalane and SE-30.

Comparison of isothermal and non-linear temperature programmed gas chromatography the temperature dependence of the retention indices of a number of hydrocarbons on squalane and SE-30

The concept of an “average temperature of elution” of a compound is proposed and used to show that a correlation may be made between retention indices determined under non-linear temperature programmed conditions and those found from plots of retention index against column temperature. The plots of Ivs. T for a number of hydrocarbons on squalane and SE-30 are given.

Studies on the conversion of methanol and other small molecules over H-ZSM-5: Yield studies and the use of 3H NMR in a reexamination of routes to ethylene production

Routes to ethylene production involving ethyl aromatic intermediates have been investigated in the conversion of methanol to gasoline over the zeolite H-ZSM-5. Yield studies and tritium NMR have shown that some of the postulated steps either do not occur or give ethyl aromatic products in very low yields. Furthermore, yields of ethylene from such ethyl aromatics are too low to be significant in methanol conversion over H-ZSM-5.

A Re-Examination of Evidence for Carbene (CH2:) As An Intermediate in the Conversion of Methanol to Gasoline. The Effect of Added Propane

Abstract Evidence in favour of carbene intermediacy in the conversion of methanol to gasoline over H-ZSM-5 involving a decrease in the abundance ratio of isobutane to that of n-butane, observed on adding propane to the feed, has been reviewed. The lowering of the i/n ratio may be accounted for in part by conversion of propane yielding butanes, predominantly n-butane. An additional effect is the exaltation of i/n ratio on adding helium as diluent in the control sample. At least the greater part of the i/n lowering effect may be attributed to these two causes.

Development of benzene sequestration test for reaction intermediates in the conversion of methanol and other small molecules to gasoline over H-ZSM-5

Abstract Reactive intermediates of types C 1 , C 2 , and C 3 formed during the conversion of methanol to gasoline over the zeolite catalyst ZSM-5 may be sequestered by adding benzene to the feedstock and seeking the resulting alkylbenzenes. Applying this “benzene sequestration test” to methanol feedstock shows a preponderance of C 1 intermediate. This is entirely absent in the conversion of ethylene and propylene. It follows that benzene is sequestering reactive C 1 intermediates in the conversion of methanol from a stage in the conversion reaction which precedes the formation of ethylene and propylene.

The reactions of hydrocarbons on transition metal catalysts in the presence of tritium: I. The labeling of cyclohexane by exchange with tritium gas on Raney nickel

Abstract The reaction of liquid phase cyclohexane at 60 ° with low-pressure tritium adsorbed on Raney nickel yielded labeled cyclohexane, benzene, and a trace of cyclohexene, the latter two being present at very low mass concentrations. The proportion of tritium incorporated (18% to 98%), the rate of incorporation of tritium, and the final distribution of activity between cyclohexane (50% to 99%) and benzene (50% to less than 0.1%) varied with the batch of catalyst. This variation is explained in terms of the distribution of the tritium between accessible and inaccessible catalyst sites. Cyclohexane of high radiochemical purity can be consistently produced by the use of high tritium to catalyst weight ratios (1800 millicuries/gram of catalyst dry weight) and long exchange times (100 hr). The results are not affected by low concentrations of benzene impurities (less than 0.1%) nor is the radiochemical purity of the product appreciably affected by the storage of the catalyst under ethanol for several months.