Proper disposal of waste plastics promotes recycling of plastic products

The direction of recycling of waste plastics:

1, the two sides of plastic

In 2016, the output of China's plastic products has exceeded 77 million tons, the output value is nearly 2 trillion, and it is increasing every year. However, perfect things cannot exist. Similarly, plastic has been crowned as one of the worst inventions of the 20th century, because its serious pollution has gradually been discovered and paid more and more attention. What is worse is that the treatment of this pollution is more difficult than people think.

Once, a generation of outstanding chemists have worked hard to achieve the excellent physical and chemical properties and durability of plastics, making plastics widely used in various fields due to its light weight, durability, aesthetics and low cost. However, it is precisely these excellent properties that produce a large amount of durable plastic pulp that has not been rotted, and the large amount of plastic products discarded after use has become the biggest murderer of the environment.

2. Disposal of waste plastics

a. Landfill treatment, because the plastic products are generally light and not easy to rot, which will result in the landfill becoming a soft foundation, which is difficult to use in the future.

b. Incineration treatment, because the plastic generates a large amount of heat, it is easy to damage the furnace, and the gas generated after incineration will promote the warming of the earth. Some plastics will release harmful gases and pollute the atmosphere when incinerated.

c. Adopting the method of recycling and reuse, due to labor consumption, high recycling cost and lack of corresponding recycling channels, the world recycling and recycling only accounts for about 15% of the total plastic consumption.

Due to the limited world oil resources, recycling of plastics is of great significance from the perspective of saving the earth's resources. To this end, all countries in the world have invested a lot of manpower and material resources to develop various key technologies for the recycling of waste plastics, and are working to reduce the cost of recycling and recycling plastics.

3. Recycling method of waste plastics

At present, there are several methods for recycling used plastics:

Thermal recovery method

Most of the main components of plastics are hydrocarbons, which are combustible. For example, polystyrene burns more heat than dye oil. However, heat recovery is one of the last methods of recycling waste plastics. Because waste plastics burn, most of them produce toxic gases, which is also a threat to the environment. The burning of halogen-containing plastics will become the culprit in the production of dioxins.

b. Physical recycling

Physical recycling is a method actively promoted and promoted now. It is an effective means to turn waste into treasure and save energy and protect the environment. However, at present, it is mainly trapped in the recycling and sorting process, and the recycling revenue is small, and the sorting is difficult and the cost is high. People are still not very aware of environmental protection, and can't effectively classify garbage.

c. Chemical reduction method

This method cuts the long chain of the polymer and restores its original properties. The cracked material can be used to make new plastics. Some methods involve the chemical cracking of the combined carbon atoms by the addition of chemical elements, or the addition of energy to cause their thermal cracking. Some materials have been recycled by this method, but most of the materials are still in the experiment.

d. Hydrogenation

In this way, mixed plastic articles can be processed, and 60%-80% of the components can be refined into synthetic crude oil according to different plastic components. In a joint research report, three chemical companies such as BASF in Germany pointed out that hydrogenation is the best way of pyrolysis, and the synthesized crude oil is good in quality and can be used for refining. This treatment treats halogen-containing waste plastics and does not produce toxic dioxins and chlorine. With the continuous improvement of this technology, it may become one of the main methods to deal with waste plastics in the future.

4. Development direction of environmentally friendly plastics

While actively developing plastic recycling technology, it is also necessary to develop or recycle plastics in a direction that is conducive to processing or recycling.

a. Reduced design

Research and development of materials suitable for recycling will not be focused on which plastics should be used to make individual parts, but rather consider materials that can be widely used. This is a revolutionary change in concept.

In order to facilitate recycling, designers began to avoid the use of a variety of plastics in the design of products, the United States BMW is preparing to reduce the number of plastics in its new car design by 40%, in order to facilitate the recycling of waste plastics.

The world's electrical and electronic market has drawn attention to the recycling of waste plastics. International Business Machines (IBM) has begun to label plastic parts for computer and business machines, and is developing reusable plastic electronic components and simplified disassembly equipment. The structure of the product is also considered to eliminate the surface coloration of the components, and the amount of external binder used to control the plastic additives is reduced by the use of recycled process parts and additional parts.

b. Biodegradation

Research and development of biodegradation has become a research hotspot in the plastics processing industry in the world. Researchers hope to develop a plastic that can degrade in a microbial environment to handle large amounts of disposable plastics, especially mulch and multi-package waste, on farmland, forests, and oceans.

The research goal is to develop a plastic that can guarantee the performance of its name during use, and once it is used up, it can be decomposed by microorganisms in the environment to completely enter the ecological cycle. At the same time, the production cost of this plastic is relatively low and economical. If it is such a biodegradable plastic, it can be composted with ordinary bio-waste after use without having to be collected, sorted and regenerated at a great cost. Moreover, the decomposition products enter the ecological cycle without causing waste of resources.