| 摘要 |
A process for preparing epichlorohydrin includes chlorinating glycerol with gaseous hydrogen chloride in a bubble column, by supplying hydrogen chloride, glycerol and a mixture of monochloropropanediol and residues of glycerol recycled from the distillation units connected downstream of the bubble column, dichloropropanol and residues to the bottom of the bubble column, and, close to the top of the bubble column, drawing off the mixture of monochloropropanediol, dichloropropanol, water, residues of glycerol and residues formed there and feeding it to at least one distillation unit, after which the dichloropropanol and water distilled off there are hydrolyzed with sodium hydroxide solution. Unconverted hydrogen chloride drawn off from the top of the bubble column is absorbed with freshly supplied glycerol in a scrubber, and this hydrogen chloride-containing glycerol is supplied at the bottom of the bubble column. Preference is given to increasing the conversion rate by using oxalic acid as a catalyst. |
