Waste Tires Cause Serious Environmental Pollution
Only in the EU, USA and Japan around 6 million tones per year of scrap tyre are produced. The huge quantity of waste tires presently produced in the world will certainly increase in the future as the associated automotive industries grow. The disposal of scrap tires becomes a serious environmental problem. The accumulation of discarded waste tires leads to environmental pollution. A large fraction of the scrap tires is simply dumped in sites where they represent hazards such as diseases and accidental fires. Rubbers are not biologically degradable, and this fact creates problems with their disposal. The impact of waste rubber on the environment can be minimized by recycling with material or energy recovery. However, during processing and moulding rubber materials are crosslinked, and therefore they cannot be simply again softened and remoulded by heating. For many years landfill, was the main, practical means for dealing with the problem of waste tires. However, landfilling of tires is declining as a disposal option, since tires do not degrade easily in landfills, they are bulky, taking up valuable landfill space and preventing waste compaction. Open dumping may result in accidental fires with high pollution emissions. In the EU countries in 1990 the percentage of tires discarded in landfills was 62% of all produced waste tires in 2000 about 35% and in 2006 (as it results from the EU legislation)this percentage will decrease to 0%. Some countries including the Slovak Republic have already banned the use of discarded tires for landfill.
What is Tyres Pyrolysis?
Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen (or any halogen). It involves the simultaneous change of chemical composition and physical phase, and is irreversible. The word is coined from the Greek-derived elements pyro “fire” and lysis “separating”.
The pyrolysis method for recycling used tyre is a technique which heats whole or shredded tires in a reactor vessel containing an oxygen free atmosphere and a heat source. In the reactor the rubber is softened after which the rubber polymers continuously break down into smaller molecules. These smaller molecules eventually vaporize and exit from the reactor. These vapors can be burned directly to produce power or condensed into an oily type liquid, generally used as a fuel. Some molecules are too small to condense. They remain as a gas which can be burned as fuel. The minerals that were part of the tire, about 40% by weight, are removed as a solid. When performed well a tyre pyrolysis process is a very clean operation and has nearly no emissions or waste.
Pyrolysis of scrap tyre can separate solids in the tire, such as steel wire and carbon black, from volatile liquid and gaseous compounds that can be used as fuel. Although the pyrolysis of waste tires has been widely developed throughout the world, there are legislative, economic, and marketing obstacles to widespread adoption.
* Put the raw material into the furnace;
* Seal the feed inlet then the bottom of the reactor will slowly heat the wastes by coal or electricity ;
* When the temperature reaches the degree of 250 to 280, we will get the crude oil ;
* The oil steam will be continuous produced until the temperature reaches 300-400°C ;
* Oil steam will flow through light and heavy components separating device ;
* Light component will enter the condenser and meanwhile the residues will be discharged automatically in succession;
* Liquefied part will be condensed to rubber oil;
* The part that cannot be liquefied will be input into heating supply system for burning by way of combustion gas purification system.
Final Products And Usage:
|1||Crude oil||45%||A. Sell directly.
B. Turn to diesel and gasoline by waste oil distillation plant.
C. Fuel materials.
|2||Carbon black||30%||A. Sell directly.
B. Reprocessing to fine carbon by carbon black refining machine.
|3||Steel wire(for waste tyre)||15%||A. Sell directly.
B. Deep processing to steel bloom by hydraulic press-packing.
|4||Flammable oil gas||10%||A. Fuel burn by use gas burn system(pyrolysis machine included).
B. Flammable gas can be storage as fuel material for heating.