NKCJS-1 (Waste Plastic Recycling) Technology
在国外对聚乙烯（PE）和聚丙烯（PP）的废弃物，很容易分离出较纯品，主要以机械再生为主，工艺为：表面除杂 → 粉碎 → 洗涤 → 干燥 → 造粒 → 包装
With the development of the plastic industry and the improvement of consumption level, the application of plastic products from industrial and agricultural production to food, clothing, housing and transportation is everywhere, and plastic waste is also coming to us in large quantities. They do not decay, do not decompose, and have become a very interesting social problem.
The main source of waste plastics is food packaging, beverage bottles, containers, and various films, which are the main part of recycling.
At present, the proportion of waste plastics in various countries is not high, and most of the plastic waste is mixed in garbage, which causes great harm to the environment.
In foreign countries, the waste of polyethylene (PE) and polypropylene (PP), it is easy to separate out the purer products, mainly based on mechanical regeneration, the process is:
surface impurity removal → crushing → washing → drying → granulation → packaging
There are two main ways of recycling PE and PP in China, one is that the scrap material in the processing is crushed and granulated according to 15 to 25% of the new material and then molded plastic products, and the other is that for the cleaner and less serious aging, it is used after crushing and cleaning granulation.
For waste plastics that are not clean, severely aged or mixed with PE and PP, chemical recycling has become a main channel, that is, it is converted into chemical raw materials or fuel oil through pyrolysis, without the need for secondary recycling, which is recognized by all countries as an effective regenerative eugenic way.
Under the condition of no oxygen, pyrolysis of mixed waste plastics has two methods: direct pyrolysis and catalytic pyrolysis, one is that the temperature required for direct pyrolysis is high (400~ 500 °C), the amount of residue is relatively large, and the gas content is large.
The second is catalytic cracking, using a two-stage device, cracking temperature of 300 ~ 400 °C, can adjust the reaction conditions and catalyst to obtain more required products, the catalyst currently used are Y-type zeolite (NKF-7) and ZSM-5 zeolite (NKF-5) and so on.