Chemical Engineering Department, University of Granada, Spain.
Waste Manag. 2022 Jan 1;137:179-189. doi: 10.1016/j.wasman.2021.11.007. Epub 2021 Nov 15.
The establishment of a method of separation of materials from Tetra Pak waste to obtain products for use as raw material, fuel or other purposes was investigated in this study. First, the feasibility of hydrothermal treatment for the production of a solid fuel (hydrochar) and solid fraction formed by polyethylene and aluminum, called composite was analyzed. The results indicated that hydrothermal treatment performed at 240 °C yield the formation of hydrochar with good properties for its use as fuel and a composite of polyethylene and aluminum. The best conversion and separation of the cardboard and polyethylene/aluminum were obtained using 120 min as operating time. Then, the recovery of the aluminum fraction from the composite by using spent olive oil waste was studied. A partial separation of the composite layers (polyethylene and aluminum) was accomplished with improved aluminum purity for higher operating temperatures. Finally, the operating conditions of the pyrolysis process for the production of a solid (char) and high purity composite (aluminum) were optimized. The characterization results indicated that both char and aluminum resulting from the pyrolysis of the Tetra Pak at 400 °C still have a significant amount of polyethylene while higher purity levels of aluminum can be obtained at temperatures equal of higher than 500 °C.
本研究旨在建立一种从 Tetra Pak 废物中分离材料以获得可作为原料、燃料或其他用途的产品的方法。首先，分析了水热处理生产固体燃料（水炭）和由聚乙烯和铝形成的固体部分（称为复合材料）的可行性。结果表明，在 240°C 下进行水热处理可生成具有良好燃料性能的水炭和聚乙烯/铝复合材料。使用 120 分钟的操作时间可获得最佳的纸板和聚乙烯/铝的转化和分离效果。然后，研究了用废橄榄油从复合材料中回收铝部分。随着操作温度的升高，通过改进铝纯度，可以实现复合材料层（聚乙烯和铝）的部分分离。最后，优化了生产固体（炭）和高纯度复合材料（铝）的热解工艺的操作条件。表征结果表明，Tetra Pak 在 400°C 下热解得到的炭和铝仍然含有大量的聚乙烯，而在高于 500°C 的温度下可以获得更高纯度的铝。
