Control of HCl generated by the poly(vinyl chloride) combustion

The poly(vinylchloride) (PVC) combustion has several problems, such as the damage of firebricks in the incinerator or additional risk by fire, because the hydrochloric acid (HCl) is generated by thermal decomposition of PVC. It has been already known that the generation of HCl under the incineration of PVC can be controlled at lower level by means of mixing calcium carbona te (CaCO3) and lithium carbonate (Li2CO3) into PVC. In this study, PVC resi n samples were prepared with CaCO3 or/and Li2CO3, which were surface-treate d and controlled in size, in order to find out optimum compositions of the trap agents for capturing HCl under the incineration. Various chemicals con taining iron have been known to accelerate the thermal decomposition of PVC resin. PVC resin samples mixed with FeO(OH) were also prepared and the cap turing effect of HCl under the incineration of samples was investigated. The capturing effect of HCl with both CaCO3 and Li2CO3 was found superior t o those with only single compound, CaCO3 or Li2CO3. The sample with CaCO3 : Li2CO3 = 3 : 1 (mole ratio) resulted in the highest capturing effect of HC l in this experiment. Furthermore, the samples mixed with a small amount of FeO (OH) were found to be efficacious for the capturing effect of HCl.