Cyclohexane Technical
Cyclohexane, hexamethylene, hexahydrobenzene, saturated hydrocarbon of alicyclic series (cycloalkane); colorless liquid with the characteristic odor.
According to GOST 14198-78, technical cyclohexane is manufactured with the following properties:
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Properties
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Standard
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Highest grade acc. to Russian Classification of products 24 1641 0120
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First grade acc. to Russian Classification of products 24 1641 0130
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1. Appearance
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Colorless transparent liquid that doesn’t have mechanical admixtures
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2. Total weight percent of the admixtures defined chromatographically, %, not more than
among them:
benzene, %, no more than
methylcyclopentane, %, no more than
methylcyclohexane, %, no more than
n-heptane, % no more than
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0,1
0,005
0,015
0,02
0,01
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0,2
0,01
0,04
0,1
0,05
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3. Sulphur weight percent, %, no more than
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0,00015
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Not subject to limitations
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Chemical and physical properties
Liquid cyclohexane is highly soluble in alcohol, simple ethers and esters. It is chloritized with amines, hydrocarbons and fatty acids. The substance is water-insoluble. When mixed with water it forms azeotropic mixtures and benzene. The same reaction happens when mixed with benzol.
Boiling temperature (°С) 80,74°С
Melting temperature (°С) 6,6°С
Ignition temperature (°С) 20°С
Self-ignition temperature (°С) 260°С
Density (g/cm3) at 20°С 0,778 g/cm3
Cyclohexane is a toxic substance that irritates human mucous membranes. TLV in atmospheric air - 1,4 mg/m3.
Cyclohexane is toxic if swallowed and causes intoxication. It has definite irritant and narcotic action.
Application field
Production of cyclohexane is essential for synthesis of other products of acute organic reactions:
- Nitrocyclohexane (on reaction with 30% HNO3 or CO2)
- Cyclohexanone and cyclohexanol (on reaction with O2)
- Intermediate products for caprolactam production, as well as adipic acid (on catalytic oxidation reaction). Last two products are used for manufacture of polyamides.
Production of cyclohexane is very important for the manufacture of such production as varnishes, paints, waxes, essential oils. It is also an extraction agent in pharmaceutical industry.
Manufacturing Method
Cyclohexane is produced by hydrogenation of benzene in vapor phase with nickel chromium catalyst.
Technological process may take place:
- in isothermal reactors (at temperature 100-250°C, pressure from 1,8 to 2,0 MPa);
- in adiabatic reactors (at temperature 90-240°C, pressure from 2,0 to 2,4 MPa).
Main cyclohexane producers use high quality raw materials (benzene and hydrogen) for synthesis of the substance with the application of nickel-chrome accelerators. This is required by the technology for the quickest possible reaction behavior.
According to physicochemical parameters, cyclohexane corresponds to GOST 14198-78 "Cyclohexane technical. Technical conditions".
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