Liquid enrichment and/or separation by absorption processes

Abstract

Abstract In a method of concentrating or separating a component of a homogenous liquid mixture of at least two substantially non-ionogenic compounds, at least one of which is organic, the mixture is contacted with a resin absorbent having a large surface area per unit weight, the resin absorbent being (a) a crosslinked addition polymer other than an ionexchange resin, (b) insoluble in the liquid mixture and (c) having a preferential absorptive capacity for the component to be concentrated. Absorption may be tested for by agitating the resin with a mixture for a given time and analysing the mixture before and after absorption. The separatory capacity of a resin is defined as <FORM:0871622/IV (b)/1> where m is the weight of the resin in grams, V is the volume of liquid mixture added in ml., and c0 and c are the volume fractions of the preferentially absorbed component in the liquid phase before and after absorption respectively. Separatory capacities of various specified resins are given for each of the following in admixture with iso-octane: 4-vinylcyclohexene, cyclohexanol, toluene, ethyl acetate, methyl ethyl ketone, styrene, chlorobenzene, ethylene dichloride, chloroform, dioxane, pyridine, naphthalene, nitrobenzene and pyrrole; for each of ethylene dichloride, styrene, and chlorobenzene in admixture with toluene; and for the first named component of each of the following mixtures: ethylene dichloride-ethyl acetate, styrene-4-vinylcyclohexene, chlorobenzene-allyl alcohol, benzene-acrylonitrile, allyl alcohol-water, chloroform-acetone. The treatment of hydrocarbon mixtures such as paraffin/naphthene, olefin/paraffin and solvent mixtures containing alcohols, ketones, hydrocarbons and esters; and also mixtures of capryl alcohol with methyl hexyl ketone and n-butanol with water is referred to. The absorption process can be carried out batchwise or continuously. In the former the liquid mixture is passed through a column packed with resin particles, or the resin particles may pass countercurrent to the liquid. When a two-component mixture A and B, of which A is preferentially absorbed, is passed over the resin, B issues first from the resin until the limit of the absorption capacity for A is reached, after which the original mixture A and B will issue. Enriched A is separated from the resin e.g. by heat, steam distillation, extraction or desorption with another solvent. In the continuous treatment the use of a desorbent C allows complete separation of A and B, and the resin supported in a column is fed alternately with liquid mixture and with desorbent. The desorbent consists of one or more liquids, is completely miscible with A and B, and has a swelling power for the resin of the same order as that of one of the components of the liquid mixture to be separated. Examples describe batch methods for partially separating tolueneiso-octane, dimethyl sebacate-iso-octane, methyl caprate-iso-octane, ethylene dichloride-cyclohexane mixtures using copolymers of divinyl benzene with 2-ethylhexyl acrylate, n-butyl acrylate, n-butyl methacrylate, ethoxyethyl acrylate, and methyl acrylate as absorbents. Examples also describe continuous methods for completely separating toluene from isooctane using n-pentane as desorbent; dimethyl sebacate from methyl stearate and/or methyl caprate using iso-octane as desorbent; ethylene dichloride from cyclohexane and chloroform from acetone using toluene as desorbent in each case; also chlorobenzene from allyl alcohol, benzene from acrylonitrile, and nitrobenzene from iso-octane using as desorbents methanol, methylene dichloride and benzene respectively. Resins used in the examples of continuous methods are n-butyl and methyl acrylates copolymerized with divinylbenzene. Specifications 786,755, 846,890 and 858,865 are referred to.ALSO:In a method of concentrating or separating a component of a homogeneous liquid mixture of at least two substantially non-ionogenic compounds, at least one of which is organic, the mixture is contacted with a resin absorbent having a large surface area per unit weight, the resin absorbent being (a) a cross-linked addition polymer other than an ion-exchange resin, (b) insoluble in the liquid mixture and (c) having a preferential absorptive capacity for the component to be concentrated. Absorption may be tested for by agitating the resin with a mixture for a given time and analysing the mixture before and after absorption. The separatory capacity of a resin is defined as <FORM:0871622/I/1> where m is the weight of the resin in grams, V is the volume of liquid mixture added in ml., and Co and C are the Volume fractions of the preferentially absorbed component in the liquid phase before and after absorption respectively. Separatory capacities of various specified resins are given for each of the following in admixture with iso-octane: 4-vinylcyclohexene, cyclohexanol, toluene, ethyl acetate, methylethylketone, styrene, chlorobenzene, ethylene dichloride, chloroform dioxane, pyridine, naphthalene, nitrobenzene, and pyrrole; for each of ethylene dichloride, styrene, and chlorobenzene in admixture with toluene; and for the first named component of each of the following mixtures: ethylene dichloride-ethyl acetate, styrene, 4-vinylcyclohexene, chlorobenzene-allyl alcohol, benzene-acrylonitrile, allyl alcohol-water, chloroform-acetone. The treatment of hydrocarbon mixtures such as paraffin/naphthene, olefin/paraffin and solvent mixtures containing alcohols. Ketones, hydrocarbons and esters; and also mixtures of capryl alcohol with methylhexyl ketone and n-butanol with water is referred to. The absorption process can be carried out batchwise or continuously. In the former the liquid mixture is passed through a column packed with resin particles, or the resin particles may pass countercurrent to the liquid. When a two-component mixture A and B, of which A is preferentially absorbed, is passed over the resin, B issues first from the resin until the limit of the absorption capacity for A is reached, after which the original mixture A and B will issue. Enriched A is separated from the resin e.g. by heat, steam distallition, extraction or desorption with another solvent. In the continuous treatment the use of a desorbent C allows complete separation of A and B and the resin supported in a column is fed alternately with liquid mixture and with desorbent. The desorbent consists of one or more liquids, is completely miscible with A and B, and has a swelling power for the resin of the same order as that of one of the components of the liquid mixture to be separated. Examples describe batch methods for partially separating toluene-iso - octane, dimethyl sebacate-iso-octane, p methyl caprate-iso-octane, ethylene dichloride-cyclohexane mixtures using copolymers of divinyl benzene with 2-ethylhexyl acrylate, n-butyl acrylate, n-butyl methacrylate, ethoxy-ethyl acrylate, and methyl acrylate as absorbents. Examples also describe continuous methods for completely separating toluene from iso-octane using n-pentane as desorbent: dimethyl sebacate from methyl stearate and/or methyl caprate using iso-octane as desorbent; ethylene dichloride from cyclohexane and chloroform from acetone using toluene as desorbent in each case; also chlorobenzene from allyl alcohol, benzene from acrylonitrile, and nitrobenzene from iso-octane using as desorbents methanol, methylene dichloride and benzene respectively. Resins used in the examples of continuous methods are n-butyl and methyl acrylates copolymerized with divinyl-benzene. Specifications 786,755, 846,890 and 858,865 are referred to.

Inventors

• 👤 Jesse C H Hwa
• 👤 Charles H Mcburney
• 👤 Erich F Meitzner

Bibliographic Details