Carbon tetra:chloride conversion by gas phase reaction with alcohol - using active alumina and/or silica catalyst bed, giving high conversion to chloride

摘要

In the gas phase reaction of CC14 with a 1-10C opt. branched mono- or polyhydric aliphatic alcohol (I) to the corresp. chloride in the presence of a solid caalyst (II), (II) consists of active oxidic cpds. of Al and/or Si. Pref. (II) is alpha-Al2O3 (IIA) or pyrogenic SiO2. (I) is a 1-5C monohydric alcohol, esp. MeOH. The (I):CCl4 molar ratio is 4:1 or higher. Reaction is carried out at 150-450, pref. 250-360 deg. C in a tubular reactor contg. a bed of (II), pref. with introduction of HCl gas. USE/ADVANTAGE - Process gives a high deg. of conversion of CCl4 to useful prods., (II) is easily mfd., since no support is necessary, and can be purfied with an O2 stream, whilst the risk of contaminating the prod. with metal salts is avoided. In an example, 110 g/hr.: mixt. of 154 pts. wt. CCl4 and 224 pts. MeOH were vaporised at 200 deg. C and mixed with 44 g/hr. HCl gas. The mixt. was passed through a Ni tubular reactor (55 mm dia.) contg. a 500 mm long bed of (IIA) (ca. 90% pure; calcination loss ca. 10%; 4 x 4 mm tablets; dry bulk density ca. 0.94 g/cc; specific pore vol. ca 0.4 cc/g; BET specific intrinsic surface area ca. 2 x 10 exp. 2 sq. m/g). Heating was regulated so that the outlet temp. was 355 deg. C. The reaction mixt. was cooled to -10 deg. C. This gas 45.5 g condensate contg. 40.7% HCl, 0.8% MeOH, 58.5% water and 0% CCl4; and 49.5 Nl gas contg. 67.3% CH3Cl;, 1.1% CC14, 22.2% HCl, 5.3% CO2 and 4.1% other. The CCl4 conversion was 91.6%. CCl4 conversions as high as 98.6% were attained by varying (II) and the reaction condition