| 摘要 |
The object of the invention is a process for the thermal recycling of waste PVC with the recovery of heat and anhydrous hydrogen chloride, in which: a) the waste PVC is burned in the presence of oxygen, and as much gaseous chlorine and/or chlorinated hydrocarbons are added to the combustion substance that, together with the hydrogen or chlorine content of the substance, there is in the mixture a total atomic ratio of hydrogen to chlorine of at least 1:1; b) the combustion gas is cooled to 500 to 1000 C, possibly after filtration, with the recovery of a major proportion of the heat of combustion released; c) said gas is cooled to 50 to 120 C by injection of aqueous hydrochloric acid in which the hydrogen chloride content corresponds to the saturation concentration at the prevailing pressures and temperatures, the major proportion of the water of combustion being condensed out, and solids precipitated from the aqueous hydrochloric acid being filtered out by the hydrolysis of volatile inorganic compounds; d) the combustion gas is further cooled to temperatures of -5 to +10 C by direct heat exchange, the residual water being condensed out as hydrochloric acid; and e) the largely anhydrous, hydrogen chloride-containing combustion gas is transferred for further use. |
