Polystyrene depolymerization: Scavenging brominated flame retardants

聚苯乙烯是一种用途广泛的聚合物，大规模生产，并应用于许多消费品，包括包装。不可生物降解的聚合物，如聚苯乙烯，是一种环境负担;发泡聚苯乙烯是市政固体中最难处理的成分之一。该行业现在正试图从废聚合物和报废聚合物中获得价值，作为原料。这种驱动减少了浪费，并且具有经济效益，因为材料成本低于石油原料的成本。热裂解和热解是回收有价值的单体-聚合物的结构单元-的几种技术之一。在这些过程中，聚合物被加热到超过400 oC甚至超过600 oC的温度，聚合物分解为苯乙烯（单体）和碳氢化合物（例如苯）。溴化化合物伴随聚苯乙烯消费品提供防火性能，以满足UL或CSA防火要求。然而，这些化合物中的许多现在被禁止。Lavergne集团是加拿大一家生产聚合物的大公司，但他们必须去除违禁化合物。我们将共同开发技术，以消除溴化化合物，以满足联邦要求。去除这些化合物可以减少聚苯乙烯对市政垃圾填埋场的负担，同时维持其客户的原料供应，因为他们有一个可行的业务运营。我们将首先在热重分析仪中测量聚苯乙烯的热性能。该数据将确定进行反应堆试验以消除溴化合物的温度范围。在下一步中，我们将在流化床反应器中加热聚苯乙烯并监测气体产物的组成。我们还将浓缩气体并在HPLC分析仪中分析水相。我们的GC-MS分析仪将识别有机相的化合物。第三步将确定吸收剂，我们可以直接添加到流化床中，以消除溴化化合物或添加后处理步骤来捕获它们。

Polystyrene is a versatile polymer that is produced at enormous scale and applied in many consumer productsincluding packaging. Nonbiodegradable polymers, like polystyrene, represent an environmental burden;expanded polystyrene is among the most intractable components in municipal solid. The industry is now tryingto derive value from waste polymer and end-of life polymer for a feedstock. This drive reduces waste and hasan economic benefit because the material costs are lower than the costs of the petroleum feedstock. Thermalcracking and pyrolysis are among the several technologies to recover valuable monomers-the building blocksof polymers. In these processes, the polymer is heated to temperatures exceeding 400 oC and even beyond 600oC and the polymer decomposes to styrene (monomer) and hydrocarbons (benzene, for example).End-of-life polystyrene contains thermal stabilizers, brominated fire retardants, benzoyl peroxide, antimonytrioxide, among others. Brominated compounds accompany polystyrene consumer products to provide fireproof properties to meet UL or CSA fire resistance requirement. However, many of these compounds are nowbanned. Lavergne Group is a major Canadian company that recycles polymers but they must remove thebanned compounds. Together we will develop technology to scavenge the brominated compounds to meetfederal requirements. Removing these compounds reduces the burden of polystyrene to municipal landfills butwill maintain their supply of feedstock for their customers as they have a viable business operational.We will first measure the thermal properties of the polystyrene in a thermogravimetric analyser. This data willidentify the temperature range to conduct reactor tests to scavenge the bromine compounds. In the next step, wewill heat the polystyrene in a fluidized bed reactor and monitor the gas product composition. We will alsocondense the gases and analyse the aqueous phase in an HPLC analyser. Our GC-MS analyser will identify thecompounds of the organic phase. The third step will identify absorbents that we can add directly into thefluidized bed to scavenge the brominated compounds or to add a post-treatment step to capture them.