Separation and determination of aromatic and monoolefin hydrocarbons in mixtures with paraffins and naphthenes by adsorption

Abstract

A new method is described for separating and determining aromatic and monoolefin hydrocarbons in mixtures with paraffins and naphthenes by adsorption. The mixture to be analysed is introduced into the top of a column of silica gel and, when the liquid level just reaches the top of the silica gel, a suitable desorbing liquid, such as ethyl alcohol, is added. The desorbing liquid forces the hydrocarbon portion down the column, during which passage the hydrocarbon portion is fractionated according to the adsorb ability of the various components. These components issue from t he bottom of the column in the following order: Paraffin plus naphthene, monoolefin, and aromatic hydrocarbons. The analysis is made by determining the fraction of the total volume constituted by each of these classes.Results of the analyses of five solut ions containing aromatic and paraffin hydrocarbons, and t hree solutions containing aromatic, mono olefin, and paraffin hydrocarbons are given. A procedure is outlined for determining the aromatic content of a straight-run petroleum distillate, as ill the gasoline or kerosine fractions CONTENTS Page

Chromatographic Analysis of Gas Oils for Hydrocarbon Types

“…Use of Strong Initial Developer (Total Displacement Development). In the adsorption technique of Mair et al (9,11, IS) the sample is added to a column of adsorbent, and alcohol (a strong developer) is added immediately thereafter to displace the entire sample down the column ahead of the alcohol. This technique thus falls in the category of displacement development.…”

“…Work by Mair provided an adsorption method for determining the total aromatic content of gasolines (9), which has now been extended to higher boiling fractions (11,13). Chromatographic techniques have also been reported by Lipkin et al (5, 7) for measuring the paraffin, monocyclic naphthene, and dicyclic contents, etc., and the total aromatic content of the higher boiling oils.…”

Molecular Structure and Properties of Lubricating Oil Components

“…There were numerous indications in the literature a t the start of the work (8)(9)(10) that silica gel percolation might be an effective tool for separation, and, accordingly, a column for this purpose was con-of structed of stainless steel tubing inch in inside diameter and 52 feet in length. There were numerous indications in the literature a t the start of the work (8)(9)(10) that silica gel percolation might be an effective tool for separation, and, accordingly, a column for this purpose was con-of structed of stainless steel tubing inch in inside diameter and 52 feet in length.…”

Components of Gasoline Produced by Catalytic Cracking

“…in dinmeter is used with an appropriately larger volume of sample (about 1 to 3 ml.). The column is packed with silica gel (200 to 300 mesh) and is equipped with a pressure connection [see Figure 1, reference ( 7 ) for details] to increase the speed of filtration. The use of these columns makes possiblc also the determination of the refractive index of the aroniat,ic portion by desorption withethanol.…”