High- and low-density polyethylene (HDPE and LDPE) and polypropylene (PP) are the most common polymers among plastic waste as they have multiple commercial applications. This study focused on thermal degradation characteristics and kinetic of a plastic mixture with a composition of 92.5 wt% LDPE and 7.5% PP. Thermal decomposition characteristics of the plastic mixture was analysed through thermo-gravimetric analysis (TGA). The overall kinetic of the process was studied using the modified Coats−Redfern method and the Ozawa-Flynn-Wall (OFW) method. The apparent activation energy (E) and pre-exponential factor (A) obtained were 316.0 kJ/mol; 8.09E+21 min⁻¹ and 311.5 kJ/mol; 4.35E+21 min⁻¹, respectively. Slow pyrolysis of the analysed mixture was carried out in a semi-batch reactor under atmospheric pressure and nitrogen atmosphere and three different pyrolysis temperatures were investigated: 420 °C, 450 °C and 500 °C. H₂, CH₄, C₂H₄, C₂H₆ and C₃H₈ were the main components of the gas phase. Liquid (oil/wax phase) yields increased with increasing operative temperature from 42% at 420 °C to 62% at 500 °C. On the other hand, solid phase showed a specular behaviour compared to the oil/wax phase, decreasing from 21% to 5% in the considered temperature range. On the contrary, gas phase did not change much with pyrolysis temperature, with a decrease from 37% at 420 °C to 34% at 500 °C. Products’ energy yields were also estimated at 420 °C. They ranged from 7.4% to 37.8% and 43.0% for solid, gas and oil fraction, respectively. Oil fraction collected from pyrolysis at 420 °C was also characterized.

高和低密度聚乙烯（HDPE和LDPE）和聚丙烯（PP）是塑料废料中最常见的聚合物，因为它们具有多种商业用途。这项研究集中于组成为92.5 wt％LDPE和7.5％PP的塑料混合物的热降解特性和动力学。通过热重分析（TGA）分析了塑料混合物的热分解特性。使用改进的Coats-Redfern方法和Ozawa-Flynn-Wall（OFW）方法研究了该过程的整体动力学。表观活化能（E）和指数前因子（A）为316.0 kJ / mol；8.09E + 21 min ^-1和311.5 kJ / mol; 4.35E + 21分钟^-1， 分别。在大气压和氮气气氛下，在半间歇反应器中对分析的混合物进行缓慢热解，并研究了三种不同的热解温度：420°C，450°C和500°C。H ₂，CH ₄，C ₂ H ₄，C ₂ H ₆和C ₃ H ₈是气相的主要成分。液相（油/蜡相）产率随操作温度的升高而增加，从420°C的42％升高到500°C的62％。另一方面，与油相/蜡相相比，固相表现出镜面行为，在所考虑的温度范围内从21％降至5％。相反，气相随热解温度变化不大，从420°C的37％降至500°C的34％。产品的能量产率也估计为420°C。固体，天然气和石油的比例分别为7.4％至37.8％和43.0％。还对在420°C下热解收集的油馏分进行了表征。