STUDIES IN EXTRACTIVE AND AZEOTROPIC DISTILLATION SERIES

Study Number 3 - SEPARATION OF HYDROCARBONS

A summary of experimental results (in outline format) from a series of investigations of hard-to-separate hydrocarbon liquid binary mixtures

For each hydrocarbon liquid pair, typically 100 to 200 different organic solvents were evaluated for potential as agents in extractive or azeotropic distillation. Tests consisted of determination of relative volatility - with and without agent - in an Othmer vapor-liquid equilibrium still.

In a number of cases (but not all), where favorable relative volatility was found in the Othmer still, a batch distillation test was conducted in a 3" diameter - 5.5 theoretical plate glass distillation column. All testing was conducted at atmospheric pressure at Bozeman MT.

Analyses were conducted by the author or his assistants using a Varian Gas Chromatograph equipped with a hydrocarbon column.

Following are a series of Tables summarizing the test series for each organic hydrocarbon separation studied in this work.

 

Agent	Relative Volatility	Notes
Isobutanol	1.18	1-hexene overhead
1-Hexanol	1.20	1-hexene overhead
Methyl amyl alcohol	1.25	1-hexene overhead
Butyl formate	1.20	1-hexene overhead
Hexyl acetate	1.27	1-hexene overhead
Hexyl formate	1.35	1-hexene overhead
2,6-Dimethyl-4-heptanone	1.25	1-hexene overhead
Propiophenone	1.30	1-hexene overhead

 

Agent	Relative Volatility	Notes
Ethyl butyrate	2.10	heptane overhead
5-Methyl-2-hexanone	1.30	heptane overhead
Di-nonyl phenol	1.35	heptane overhead
Diacetone alcohol	1.45	1-heptene overhead, VLE still & 3" col. tests
Acetophenone	1.25	1-heptene overhead, VLE still & 3" col. tests
Dimethylacetamide	1.35	1-heptene overhead, VLE still & 3" col. tests
Dimethyl sulfoxide	1.58	1-heptene overhead, VLE still & 3" col. tests

Table 3 - 1-octene/octane Separation

 

Agent	Relative Volatility	Notes
Methyl acetate	1.5	1-octene overhead
Ethyl acetate	1.6	1-octene overhead
Dimethyl acetamide	1.5	1-octene overhead
Ethyl formate	1.9	octane overhead, VLE and 3" col. test
t-Amyl methyl ether	1.8	octane overhead, VLE and 3" col. test

Table 4 - octene/isomers Separation

 

Agent	Relative Volatility	Notes
Isophorone	1.45	ED - isomers overhead
Phenethyl alcohol	1.95	ED - isomers overhead
Ethyl valerate	3.0	ED - isomers overhead
t-Amyl methyl ether	2.1	AZ separation, VLE & 3" col. tests, Isomers overhead
Isopropyl ether	1.75	AZ separation, isomers overhead
Isopropyl acetate	1.8	AZ separation, isomers overhead
Methyl butyl ether	2.0	AZ separation, isomers overhead

 

Agent	Relative Volatility	Notes
Isobutanol	1.18	1-hexene overhead
1-Hexanol	1.20	1-hexene overhead
Methyl amyl alcohol	1.25	1-hexene overhead
Butyl formate	1.20	1-hexene overhead
Hexyl acetate	1.27	1-hexene overhead
Hexyl formate	1.35	1-hexene overhead
2,6-Dimethyl-4-heptanone	1.25	1-hexene overhead
Propiophenone	1.30	1-hexene overhead

Table 6 - a -phellandrene/3-carene Separation

 

Agent	Relative Volatility	Notes
Methyl formate	1.7	Phellandrene overhead
Methyl caproate	2.7	Phellandrene overhead
Methyl amyl acetate	1.85	Phellandrene overhead - VLE and 3" col. tests
Acetal	2.0	Carene overhead
Nitroethane	1.3	Carene overhead
Nitromethane	1.5	Carene overhead
Ethyl acetate	1.25	Carene overhead

Table 7 - menthane/cymene Separation

 

Agent	Relative Volatility	Notes
Methyl benzoate	1.64	ED - menthane overhead, VLE and 3" col. tests
Nonyl alcohol	1.8	ED - menthane overhead
Isobutyl heptyl ketone	1.4	ED - cymene overhead
Cyclododecanol	3.9	ED - cymene overhead
Isobutanol	2.4	AZ - menthane overhead, VLE and 3" col. tests
Diethylene glycol ethyl ether	3.8	AZ - menthane overhead
1-Pentanol	2.7	AZ - cymene overhead
Dipropylene glycol methyl ether	2.1	AZ - cymene overhead

 

Agent	Relative Volatility	Notes
Dimethylsulfoxide	175	ED - cyclohexane overhead
Methyl acetoacetate	2.0	ED - cyclohexane overhead
2-Furaldehyde	2.1	ED - cyclohexane overhead
3-Ethyl phenol	1.6	ED - cyclohexane overhead
Dimethoxy methane	1.78	AZ - cyclohexane overhead, VLE and 3" col. tests
Methyl acetate	2.4	AZ - cyclohexane overhead
2,2-Dimethoxy propane	1.65	AZ - benzene overhead
Methanol	1.6	AZ - cyclohexane overhead

Table 9 - toluene/methyl cyclohexane

 

Agent	Relative Volatility	Notes
Glycerol triacetate	2.85	Methylcyclohexane overhead
Phenol	2.95	Methylcyclohexane overhead
Furfural	3.35	Methylcyclohexane overhead
Acetophenone	2.68	Methylcyclohexane overhead
Dimethylformamide	3.6	Methylcyclohexane overhead
2-Nitrotoluene	2.55	Methylcyclohexane overhead
Triethylene glycol diacetate	3.1	Methylcyclohexane overhead
Maleic and phthalic anhydride/ glycerol triacetate mixture	4.1	Methylcyclohexane overhead, VLE & 3" col. tests

Table 10 - cyclohexane/cyclohexene

 

Agent	Relative Volatility	Notes
Dimethylacetamide	1.3	ED - cyclohexane overhead
Dimethylacetamide + acetophenone	1.34	ED - cyclohexane overhead
Diacetone alcohol	1.23	ED - cyclohexane overhead, VLE & 3" col. tests
Propylene glycol methyl ether	1.25	ED - cyclohexane overhead
Ethanol	1.39	AZ - cyclohexane overhead
n-Propanol	1.43	AZ - cyclohexane overhead
n-Butanol	2.0	AZ - cyclohexane overhead
Ethylene glycol methyl ether	2.3	AZ - cyclohexane overhead

STUDIES IN EXTRACTIVE AND AZEOTROPIC DISTILLATION SERIES