Zhongguo youzhi (Dec 2023)
混合废塑料和餐厨废油添加甲醇共催化裂解制备 生物基烃类的研究Preparation of bio-based hydrocarbons by co-catalytic pyrolysis of waste plastics and kitchen waste oil with methanol
Abstract
为了将农业生产中的废塑料和餐厨废油更好地进行资源化利用，以农业混合废塑料和餐厨废油为原料，NaY分子筛为催化剂，探究在不同的反应温度下甲醇添加量对混合废塑料和餐厨废油共催化裂解制备生物基烃类的影响。以液体产物产率、可燃气体产量、液体产物酸值、催化剂结焦率为指标，确定了混合废塑料和餐厨废油共催化裂解的最佳反应条件，同时对最佳反应条件下所得液体产物的组成进行了分析，对比了液体产物和生物柴油的理化指标，并对混合废塑料和餐厨废油共裂解反应机制进行了分析。结果表明：添加甲醇总体上有利于提高液体产物产率，降低液体产物的酸值、可燃气体产量和催化剂结焦率；混合废塑料和餐厨废油共催化裂解的最佳反应条件为反应温度440 ℃、甲醇添加量5%，在此条件下液体产物产率为78.52%，液体产物酸值（KOH）为0.59 mg/g，催化剂结焦率为6.06%；与未添加甲醇相比，添加5%的甲醇后，液体产物的组成成分中芳香烃和烯烃相对含量均降低，而烷烃相对含量显著增加；液体产物（烃类燃油）性能优于生物柴油；在添加5%甲醇条件下，混合废塑料和餐厨废油在NaY分子筛催化剂作用下可能发生协同加氢反应，促进了烷烃的生成。综上，混合废塑料和餐厨废油添加甲醇共催化裂解是制备烃类燃油的有效途径。In order to make better use of waste plastics in agricultural production, and kitchen waste oil the effects of methanol additions on the co-catalytic pyrolysis of mixed waste plastics and kitchen waste oil to prepare bio-based hydrocarbons at different reaction temperatures were investiated by using agricultural mixed waste plastics and kitchen waste oil as raw materials and NaY zeolite as catalyst. The optimum reaction conditions of co- catalytic pyrolysis of mixed waste plastics and kitchen waste oil were determined by the yield of liquid products, the yield of combustible gas, the acid value of liquid products and the coking rate of catalyst. The composition of the liquid products obtained under the optimum reaction conditions was analyzed, and the physicochemical indexes of the liquid products were compared with biodiesel. At the same time, the co-catalytic pyrolysis reaction mechanism of mixed waste plastics and kitchen waste oil was analyzed. The results showed that the addition of methanol might generally beneficial to improve the yield of liquid products, reduce the acid value of liquid products, the yield of combustible gas and the coking rate of catalyst. The optimum reaction conditions of co- catalytic pyrolysis were determined as follows: reaction temperature 440 ℃, methanol dosage 5%. Under the optimum conditions, the yield of liquid products reached 78.52%, the acid value of liquid product was reduced to 0.59 mgKOH/g, and the coking rate of catalyst was reduced to 6.06%. Compared with the absence of methanol, the relative contents of aromatic hydrocarbons and olefins in the composition of the liquid product decreased after adding 5% methanol, while the relative content of alkanes increased significantly. The performance of the liquid products (hydrocarbon fuel) was better than that of biodiesel. Adding 5% methanol might promote the generation of alkanes due to a synergistic hydrogenation reaction occuring between the mixed waste plastic and kitchen waste oil under the action of NaY zeolite catalyst. In summary, co-catalytic pyrolysis of mixed waste plastics and kitchen waste oil with methanol is an effective way to prepare hydrocarbon fuel.
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