随着塑料使用量的大增,废旧塑料如聚苯乙烯的回收利用问题已经引起广泛关注。苯类物质是聚苯乙烯的优良溶剂,在超临界条件下其优异的传质、传热性能使聚苯乙烯快速降解。在高压反应釜中,反应温度350~390℃下以甲苯为超临界溶剂考察了聚苯乙烯(PS)的降解特性,分析了温度、原料配比和催化剂对聚苯乙烯降解过程的影响,结果表明温度对降解过程影响最大,是影响苯乙烯收率的最主要的因素,反应温度达到360℃时聚苯乙烯几乎完全降解。
As the great increase of plastic, waste and worn plastic caused serious environmental pollution. Simultaneously it contained important regeneration resources. At present much attention was paid on plastic recycling by the world, and massive manpower, material resource and even the legislation was put into plastic recycling and the development of key technology on plastic recycling. Benzene hydrocarbons are the fine solvents of polystyrene. All the solvents have unique properties such as excellent heat transfer and mass transfer at supercritical conditions. The degradation of polystyrene in supercritical toluene was studied at 340-400~C by using a novel fast reactor. And the influence of reaction temperature, ratio of toluene/plastic and catalyst on the degradation was investigated. The experiments showed that the influence of reaction temperature on the degradation was the greatest. The conversion of polystyrene was close to thorough degradation when the temperature reached 360 ℃.