Page 211 - Chemical and process design handbook

Speight_Part II_C 11/7/01 3:08 PM Page 2.151

CARBON TETRACHLORIDE

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Carbon tetrachloride (melting point: –23 C, boiling point: 76.7 C, density:
1.5947, critical temperature 283.2°C, critical pressure 9714 psi – 67 MPa,
solubility 0.08 g in 100 g water) is a heavy, colorless, nonflammable, non-
combustible liquid. Dry carbon tetrachloride is noncorrosive to common
metals except aluminum. When wet, carbon tetrachloride hydrolyzes and
is corrosive to iron, copper, nickel, and alloys containing those elements.
Carbon tetrachloride is manufactured by the reaction of carbon disulfide
and chlorine, with sulfur monochloride as an important intermediate.
CS + 3C1 → S Cl + CCl
2 2 2 2 4
CS + 2S C1 → 6S + CCl
2 2 2 4
The reaction must be carried out in a lead-lined reactor in a solution
of carbon tetrachloride at 30°C in the presence of iron filings as catalyst.
The elemental sulfur can be reconverted to carbon disulfide by reaction
with coke.
6S + 3C → 3CS
4 2
Chlorination of methane and higher aliphatic hydrocarbons is also used
to manufacture carbon tetrachloride.

CH + 4Cl → CCl + 4HCI
4 2 4
The chlorination of methane is also used to manufacture partially chlo-
rinated methane derivatives.
4CH + 10Cl → CH Cl + CH Cl + CHCl + CCl + 10HCl
4 2 3 2 2 3 4
The reaction is carried out in the liquid phase at about 35°C, and ultra-
violet light is used as a catalyst. The same reaction can be carried out at
475°C without catalyst. The unreacted methane and partially chlorinated
products are recycled to control or adjust the yield of carbon tetrachloride.

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