聚乙烯塑料与重油催化共热解工艺研究

Study on Catalytic Co-pyrolysis Process of Polyethylene Plastic and Heavy Oil

以低密度聚乙烯作为塑料的模型化合物,以固体石蜡作为重油的模型化合物,以HZSM-5分子筛作为催化共热的催化剂,采用热重实验分析了两者在热解过程中的相互作用,采用固定床热解实验分析了不同物料配比下共热解产物组分分布情况。研究发现,在催化条件之下低密度聚乙烯与固体石蜡的共热解相互作用较非催化条件下要显著增强;低密度聚乙烯与固体石蜡催化共热解能够促进热解重油的轻质化,能够降低热解重油中C21+重油馏分选择性与提升C21-轻油馏分及芳烃的选择性,促使更多的气相产物、更少的油相产物及固相残渣生成,且固体石蜡在原料中的比例越大,催化共热解产物中的轻质组分与芳烃占比越多。

Low density polyethylene was used as model compound of plastics,solid paraffin as model compound of heavy oil,HZSM-5 molecular sieve as catalyst for CO heating,the interaction between the two in the pyrolysis process was analyzed by thermogravimetric experiments,the distribution of co-pyrolysis products under different material ratios was analyzed by fixed bed pyrolysis experiment.It is found that the co-pyrolysis interaction between low-density polyethylene and paraffin wax under catalytic conditions is significantly enhanced compared to under non-catalytic conditions;the catalytic co-pyrolysis of low-density polyethylene and solid paraffin can promote the light weight of pyrolysis heavy oil,can reduce the selectivity of C21+heavy oil fraction in pyrolysis heavy oil and improve the selectivity of C21-light oil fractions and aromatics,promote more gas phase products,less oil phase products and solid residue formation,moreover,the greater the proportion of the paraffin wax in the raw material,the more the proportion of the light component and the aromatic hydrocarbon in the catalytic co-pyrolysis product.