Plastic recycling in China
Plastic recycling refers to the use of a certain recycling process to recycle and reuse waste plastics to achieve the purpose of turning waste into treasure. At present, the main waste plastics in China are plastic film, plastic silk and knitted goods, foam plastics, plastic packaging boxes and containers, daily plastic products, plastic bags and agricultural film, etc.
Introduce
With the increasing consumption of plastic products, waste plastics are also increasing. In addition, the annual consumption of plastics for automobiles in China has reached 400,000 tons, and the annual consumption of plastics for electronic appliances and household appliances has reached more than 1 million tons. These products have become one of the important sources of waste plastics after they are scrapped. It is understood that in 2004, domestic waste plastics had reached about 11 million tons. If these waste plastics are not properly used and treated, they will destroy the environment and endanger people's health.
Recycling application
1. regenerated material
With the rise of global crude oil prices, the price of plastic products, one of the derivatives of petroleum, has naturally risen, and the recycling of waste plastics has also been mentioned as the most important position. Recycling of waste plastics has been widely adopted by modern chemical enterprises. After manual screening and classification, waste plastics have to be crushed, granulated, modified and other processes to become transparent and opaque plastic particles, then classified according to the phase, and finally become reusable recycled materials.
Fuel
In the first place, a large number of plastic recycling methods were used for landfill or incineration, resulting in huge waste of resources. Therefore, waste plastics are used in blast furnace injection instead of coal, oil and coke, cement rotary kiln instead of coal to produce cement, and waste solid fuel (RDF) for power generation abroad, with satisfactory results.
RDF technology was first developed by the United States. In recent years, in view of the shortage of landfills, the serious corrosion of HCI to boilers in incinerator treatment of chlorine-containing waste plastics, and the dioxin pollution of the environment during combustion, Japan has made use of the high heating value of waste plastics to mix various combustible garbage to produce 20933 kJ/kg heat and RDF with uniform particle size, even if chlorine is obtained.
It is also easy to store, transport and provide coal for other boilers and industrial furnaces.
The technology of injecting waste plastics into blast furnace is also a new method of treating waste plastics by using waste plastics as raw materials to make suitable particle size, instead of coke or pulverized coal. The application of waste plastics in blast furnace injection abroad shows that the utilization rate of waste plastics reaches 80%, the discharge amount is 0.1%-1.0% of the incineration amount, the harmful gas produced is less, and the treatment cost is lower. The technology of injecting waste plastics into blast furnace opens up a new way for the comprehensive utilization of waste plastics and the control of "white pollution", and also provides a new means for energy saving and efficiency enhancement of metallurgical enterprises. Germany and Japan have been successfully applied since 1995.
Electricity generation
Solid waste fuel power generation was first used in the United States, and there are 37 RDF power plants, accounting for 21.6% of the total. Japan has realized the enormous potential of waste plastics for power generation. Japan has changed some small refuse incineration stations into RDF production stations in combination with overhaul so as to centralize and generate electricity continuously and efficiently on a large scale, so that the steam parameters of refuse power stations can be increased from 30012 to 4052 or so, and the power generation efficiency can be increased from 15% to 20% - 25%.