CHEMICAL RECYCLING METHODS OF WASTE PLASTICS

Recycling plastic will reduce the amount of waste to be treated while reducing the pressure on virgin plastic materials. Plastic recycling also reduces energy and water consumption and emission toxic gases and chemicals in the production of biochemical materials.

In the process of recycling plastic, the final products can eventually replace the biochemical materials and will create significant economic and environmental benefits. Plastic recycling can be done in three main ways: mechanical recycling, chemical recycling (or recycling raw materials) and heat recycling.

Mechanical recycling

This is a simple and popular method used for most plastic waste. Mechanical recycling is a way to create new products from not changing plastic waste. This method was developed in the 1970s and is currently used by hundreds of manufacturers around the world.

Waste is recycled by mechanical methods until now, most of them are industrial plastic waste. Industrial plastic waste generated in manufacturing, processing, and distributing plastic products is suitable for use as raw materials for mechanical recycling thanks to the clear separation of different types of plastic, and waste at the same time. Industrial plastic has low dust and impurities and in large quantities.

All types of recycled products are made from industrial plastic including storage, benches, fences, children's play equipment, packaging products, transportation, construction, houses, parks, parks , roads, railways, other goods and vehicles used in agriculture, forestry and fisheries.

Recycled products have some attractive features that they are durable, light, easy to process and easy to cut, like wood. Recycled products with these properties are expected to be used as other materials, such as steel, concrete, wood, and the separating blocks between

Chemical recycling – Monomer

This method is mainly for restoring monomers through reducing polymerization. While PET bottles can be recycled to make textile and plastic sheets, they cannot be used to make PET bottles. This is because the used Pet bottle is not suitable as a raw material for beverage bottles, wine or soy sauce for hygiene and smell. However, converting PET bottles back to the previous state is more economical than producing PET plastic from kerosene and oil.

This method decomposes the scrap bottle into their monomers (reducing polymers) then they are used to produce PET bottles.

Heat recycling

At steel, iron ore, coal and auxiliary raw materials, it is put into iron and iron ore melted iron ore to produce cast iron.

The plastic process is used as the following reducing agent: plastic waste collected from factories and households is removed from non -burning substances and other impurities such as metal, then crushed into fine powder and close the block to reduce the volume. PVC does not contain PVC with grain creation and put into a coal -using furnace. PVC plastic is put into the oven after being separated hydrochloride at a high temperature of about 350oC and no oxygen due to the emission of hydrochloride can damage the furnace. After being separated, hydrochloride is recovered in the form of hydrochloric acid and is used for other purposes.

REFERENCE SOURCE: 

1. Reasearch gate - Chemically Recyclable Polymers: A Circular Economy Approach to Sustainability of Miao Hong 

2. Science Direct website