NKCJS-1（廢塑料再生利用）技術

NKCJS-1 (Waste Plastic Recycling) Technology

隨著塑料工業的發展和消費水平的提高，塑料制品的應用從工農業生產到衣食住行無處不在，塑料垃圾也隨之大量的向我們襲來。它們不腐爛、不分解，已經成為十分注目的社會問題。

廢塑料主要來源為食品包裝，飲料瓶，容器及各種薄膜等制品，是可回收利用的主要部分。

目前各國的廢塑料的處理比例都不高，大部分塑料廢品混合在垃圾中，對環境造成極大危害。

在國外對聚乙烯（PE）和聚丙烯（PP）的廢棄物，很容易分離出較純品，主要以機械再生為主，工藝為：表面除雜 → 粉碎 → 洗滌 → 干燥 → 造粒 → 包裝

中國對PE和PP回收利用方式主要有兩種，一是對于加工中的邊角料破碎造粒后按15~25％摻入新料中再模塑料制品，另一是對于較清潔且老化不十分嚴重的則經破碎和清洗后造粒降格使用。

對于不清潔，嚴重老化或PE、PP混在一起的廢塑料，化學再生則成為一個主渠道，即通過熱解轉化為化工原料或燃油，毋需二次回收，是各國公認有效再生優生途徑。

混合廢塑料在無氧條件下，熱解有直接熱解和催化熱解兩種方法，一是直接熱解所需溫度高（400~500℃），殘渣量相對多，氣體含量大；

二是催化裂解，采用二段式裝置，裂解溫度為300~400℃，可以調節反應條件和催化劑以得更多的要求產品，目前使用的的催化劑有Y型沸石（NKF-7）及ZSM-5沸石（NKF-5）等。

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.