Process intensification of solvent-targeted recovery and precipitation (STRAP) of multilayer plastic packaging films.
Process intensification of solvent-targeted recovery and precipitation (STRAP) of multilayer plastic packaging films.
复制标题
多层塑料包装薄膜的溶剂定向回收和沉淀 (STRAP) 工艺强化。
作者：
Kevin L. Sánchez;Panzheng Zhou;Min Soo Kim;Leonardo D González Chávez;Steve Grey;K. Nelson;Shao;Ive Hermans;V. Zavala;R. V. Van Lehn;G. Huber
我们最近报道了一种称为溶剂定向回收和沉淀（STRAP）的处理策略，通过选择性溶解将多层塑料包装薄膜分解成其组成树脂。该策略使用一系列的溶剂洗涤，由聚合物溶解度的热力学计算指导。在这项工作中，减少了反溶剂在STRAP工艺中的使用，并考虑了溶剂混合物，以实现多层膜中目标聚合物的温控溶解和沉淀。这被认为是进一步改进STRAP程序及其估计费用的一种手段。基于不同的聚合物沉淀技术，对两种方法进行了比较：添加反溶剂沉淀（STRAP- a）和降低溶剂温度沉淀（STRAP- b）。这两种方法都能够以接近100%的材料效率分离主要由聚乙烯（PE）、乙烯醇（EVOH）和聚对苯二甲酸乙二醇酯（PET）组成的后工业薄膜中的组成聚合物。技术经济分析表明，使用STRAP-B的再生树脂的最低销售价格（MSP）比使用STRAP-A的树脂低39.5%。这证明了热驱动聚合物沉淀是减少反溶剂使用的一种选择，使STRAP工艺更具经济和环境吸引力。第三种工艺，STRAP-C，用另一种不同成分的后工业多层膜进行了演示。
We recently reported a processing strategy called Solvent-Targeted Recovery And Precipitation (STRAP) to deconstruct multilayer plastic packaging films into their constituent resins by selective dissolution. This strategy uses a series of solvent washes that are guided by thermodynamic calculations of polymer solubility. In this work, the use of antisolvents in the STRAP process was reduced and solvent mixtures were considered to enable the temperature-controlled dissolution and precipitation of the target polymers in multilayer films. This was considered as a means to further improve the STRAP process and its estimated costs. Two STRAP approaches were compared based on different polymer precipitation techniques: precipitation by the addition of an antisolvent (STRAP-A) and precipitation by decreasing the solvent temperature (STRAP-B). Both approaches were able to separate the consitituent polymers in a post-industrial film composed primarily of polyethylene (PE), ethylene vinyl alcohol (EVOH) and polyethylene terephthalate (PET) with near 100% material efficiency. Technoeconomic analysis indicates that the minimum selling price (MSP) of the recycled resins with STRAP-B is 39.5% lower than that achieved with STRAP-A. This provides evidence that thermally-driven polymer precipitation is an option to reduce the use of antisolvents, making the STRAP process more economically and environmentally attractive. A third process, STRAP-C, was demonstrated with another post-industrial multilayer film of a different composition.