废弃聚丙烯塑料催化热解制取可燃气的实验研究

Experimental Study on Catalytic Pyrolysis of Waste Polypropylene Plastics to Produce Combustible Gas

本文考察了载气流速、热解温度、催化剂种类、催化剂/原料混合比四个工况条件对废塑料催化热解转化为可燃气的影响。载气流速分别为200mL/min、300mL/min、400mL/min和500mL/min,热解温度分别为650℃、750℃、850℃和950℃,选择CaO、NiO、Fe_(2)O_(3)和Al_(2)O_(3)为催化剂,催化剂/塑料混合比设置为1:2、1:1、3:2和2:1,研究废弃聚丙烯塑料的产气特性。结果表明:400mL/min载气流速下聚丙烯热解气的热值最高;塑料热解气在反应温度为850℃时达到最大值;所选的四种催化剂之中,CaO催化活性最高;催化剂/原料混合比为3:2时热解气热值达到34.551MJ/Nm^(3),进一步加大催化剂用量对气体热值无明显提升效果。

The effects of carrier gas flow rate,pyrolysis temperature,catalyst type and catalyst/raw material mixture ratio on catalytic pyrolysis of waste plastics into combustible gas were investigated.The carrier gas flow rates were 200 mL/min,300 mL/min,400 mL/min and 500 mL/min,and the pyrolysis temperatures were 650℃,750℃,850℃and 950℃,respectively.CaO,NiO,Fe_(2)O_(3)and Al_(2)O_(3)were selected as catalysts.The catalyst/plastic mixture ratio was set at 1:2,1:1,3:2 and 2:1 to study the gas production characteristics of waste polypropylene plastics.The results showed that the calorific value of polypropylene pyrolysis gas was the highest at 400 mL/min carrier gas flow rate.The pyrolysis gas of plastic reaches its maximum value at 850℃.Among the four catalysts,CaO has the highest catalytic activity.When the mixture ratio of catalyst/raw material is 3:2,the calorific value of pyrolysis gas reaches 34.551 MJ/Nm^(3),and further increasing the amount of catalyst has no obvious effect on the calorific value of gas.