Decomposition and conversion of waste thermosetting plastics to resources by low temperature steam plasma

建立合成聚合物循环利用系统是减少环境负荷的重要途径之一，目前已开发出多种热塑性塑料技术，如将热塑性塑料转化为燃料油的技术，但热固性塑料的技术还很少。本项目研究了利用水等离子体技术对不饱和聚酯塑料的热硬化性塑料进行分解，以实现产品的资源化利用。H2O等离子体同时产生氢自由基和羟基自由基，对废旧热固性塑料有较好的降解效果。在热解实验中，干冰-甲醇冷集捕集的产物主要由甲醇、乙醇、丙酮、1-丙醇、2-甲基-2-丙醇、2-甲基-1-丙醇、乙二醇、1-戊醇等8种化合物组成。另一方面，在热分解反应中发现了13种与主要产物类似的化合物，如甲醇、乙醇、丙酮、2-丙醇、1-丙醇、2-丙醇、2-甲基-2-丙醇、2-丁醇、2-甲基-1-丙醇、1-丁醇、3-戊醇、2-甲基-1-丁醇、丙醇。等离子体系统可以实现工艺过程中的废物零排放，即环保工艺。

Building up the recycling system of synthetic polymer is one of the important solution for the reduction of environmental load and several techniques has been developed for the thermoplastics such as conversion techniques to fuel oil but very few for the thermosetting plastics. In this project, decomposition of thermally hardening plastics of unsaturated polyester-plastics using H_2O plasma technique was investigated to reuse the products as resources. Both hydrogen and OH radicals were generated from H_2O plasma and those were effective to decompose the waste thermosetting plastics. In the experiment of thermal degradation, the products trapped at cold trap with dry ice-methanol comprise eight compounds of C_1 to C_5 alcohol as the main products such as methanol, ethanol, acetone, 1-propanol, 2-methyl-2-propanol, 2-methyl-1-propanol, ethylene glycol, 1-pentanol. On the other hand, thirteen compounds of C_1 to C_5 alcohol were found similar as in thermal decomposition reaction as the main products such as methanol, ethanol , acetone, 2-propanol, 1-propanol, 2-propen-1-ol, 2-methyl-2-propanol, 2-butanol, 2-methyl-1-propanol, 1-butanol, 3-pentanol, 2-methyl-1-butanol, propylene glycol. The plasma system could realize zero emission of waste during the process ; i.e. environmentally friendly process.