Degradation and Recycling of Waste Plastics and Polychlorinated Biphenyls Using Copper Oxides and Aqueous Alkaline Solution

1.废塑料的降解和回收利用用氧化铜和碳酸钾水溶液对聚乙烯或聚对苯二甲酸乙二酯进行降解，发现反应生成的烃类混合物的产率分别为1.3%和22.4%，低于其他方法得到的产率。因此，将这种降解方法应用于聚氯乙烯的降解，观察到：(1)在500℃的碳酸钾水溶液中降解聚氯乙烯得到了产率为15%的烃类混合物。(2)在上述反应混合物中加入氧化铜(II)可提高苯产率。(3)用本方法降解聚氯乙烯和聚乙二醇混合物生成的焦炭，得到含苯量较低的碳氢化合物混合物。(4)聚氯乙烯降解反应的主要反应产物是碳氧化物K_xC_yO_γ的水溶性钾盐。由于聚氯乙烯中的氯原子被定量地转化为氯化钾，因此本方法被认为是将聚氯乙烯转化为无害材料的良好方法。多氯联苯的降解和循环利用在超临界水中用碳酸钾对多氯联苯的模型化合物4-氯联苯进行降解，得到以下结果：(1)联苯、苯、甲苯、甲烷和≧C_2脂肪烃；(2)加入氧化铜提高苯产率；(3)以无机物形式生成二氧化碳；(4)得到水溶性化合物。(5)由于氯原子定量地转化为氯化钾，该方法被认为是将多氯联苯转化为无害化合物的良好方法。

1. Degradation a and Recycling of Waste PlasticsSince Degradation a of polyethylene or polyethylene terephthalate using a mixture of copper(II) oxide and aqueueous potassium carbonate solution was conducted and it was revealed that the reactions gave a mixture of hydrocarbons in the yields of 1.3 and 22.4 %, respectively, which were lower than the yields obtained by other methods. Therefore, this degradation method was applied to degradation of poly(vinyl chloride), (PVC) following observation being obtained.(1) Degradation of PVC wtiht aqueous potassium carbonate solution at 500 ℃ gave a mixture of hydrocarbons in the yields of 15 %.(2) Addition of copper(II) oxide to above stated reaction mixture brought about an increase of the yield of benzene, yield of benzene being 12 %.(3) Degradation of chars formed from a mixture of PVC and PEG by the present method gave a mixture of hydrocarbons containing lower amounts of benzene.(4) Main reaction product of the present degradation reaction of PVC is water soluble potassium salts of carbon oxides K_xC_yO_γ. Since chlorine atom of PVC was quantitatively converted to potassium chloride, the present method is considered to be good method for conversion of PVC to harmless materials.2. Degradation and Recycling of Polychlorinated BiphenylsDegradation of 4-chlorobiphenyls as a model compound of polychlorobiphenyls (PCB) using potassium carbonate in supercritical water was conducted and following observation were obtained.(1) Biphenylol, benzen, toluene, methane, and ≧C_2 aliphatic hydrocarbons were obtained.(2) Addition of copper(II) oxide brought about an increase of benzene yields(3) Carbon dioxide HCO_3 were obtained as inorganic compounds.(4) Water soluble compounds were obtained.(5) Since chlorine atom was quantitatively converted to potassium chloride, this method is considered to be good method of conversion of PCB to harmless compounds.