混合聚烯烃热裂解动力学建模

通过混合聚烯烃在633.15~673.15K、初始反应压力6.325kPa条件下的釜式热裂解实验，考察了反应温度和反应时间对裂解反应生成的产物分布的影响，并建立了四集总动力学模型，对聚烯烃制备高附加值产品的最佳工艺条件进行了优化。结果表明，利用该模型计算得到的产物分布与实验数据吻合较好，误差较小；混合聚烯烃裂解的总表观活化能为110.4 kJ/mol，指前因子(A)为2.69×107 min^-1，塑料添加剂的存在一定程度上降低了反应活化能。在653.15 K下混合聚烯烃裂解反应40 min，重组分收率最高，达到57.2%；在673.15 K下混合聚烯烃裂解反应120 min，中间组分收率最高，达到57.0%。这一研究结果可为废弃塑料热裂解制备高附加值产品提供理论指导。

Dynamics Modeling of Pyrolysis of Mixed Polyolefin

Pyrolysis of mixed polyolefin was carried out in an autoclave under the reaction temperatures of 633.15~673.15K, initial pressure of 6.325kPa. The influences of reaction temperature and time on the product distribution of polyolefin pyrolysis were investigated. A four-lump kinetic model was also established. Finally, the optimum process conditions were found to obtain maximum yield of value-added products. The results showed that the four-lump kinetic model fit for the pyrolysis reaction of polyolefin. The results calculated by the kinetic model agreed well with experimental data. The overall activation energy and pre-exponential factor was estimated to be 110.4 kJ/mol and 2.69×107 min^-1 for the pyrolysis of mixed polyolefin. The apparent activation energy reduced in the presence of plastic additives. The heavy fractions yield could reach its highest value of 57.2%, when the mixed polyolefin was pyrolyzed at 653.15 K for 40 min, and the middle distillate yield was up 57.0%, when the mixed polyolefin was pyrolyzed for 120 min at 673.15 K. The conclusions can provide theoretic direction for conversion of waste plastic to value-added products.