ELT End-of-life Tires: problem or opportunity?

The report “L’Italia del riciclo 2010” (Italy Recycling 2010) by the Italian Ministry for the Environment and ISPRA is one of the many studies presenting waste management principles and addressing the issue of ELTs. 

In dealing with tires, the many reports indicate that the first problem to be addressed is the inventory and the waste management characteristics of ELTs. This issue is particularly relevant in countries listed as emerging economies. For example, the current evolution of the Chinese economy has dramatically contributed to the increase in generation of used tires.

The United States have now been replaced by China as world leader in ELT generation, with over 200 million tires per year (approximately 5 million tons). 

Although until recently ELTs were sent to dedicated or mixed waste landfills, legislation was passed banning (with few exceptions) landfill disposal in the USA and, since July 2003, in Europe. Nevertheless, approximately one third of the 13.5 million tons of ELTs produced every year in the world are still either disposed of in uncontrolled or illegal landfills or burned. 

PROBLEM
SMOKE COMPOSITION FROM UNCONTROLLED BURNING OF ELTs

COMPONENTCONCENTRATION
(g/kg of burnt ELTs)
CO21.450
CO35
N2O0,9
NO3,2
SO215
HCN4
HCI-
UNBURNT HYDROCARBONS
(Benzene, Toluene, etc)		23
POWDERS285
METALS (included Al and Zn)31,9
IPA0,0633
PCB2,66 * 10-4
DIOXINS/FURANS6,44 * 10-7
Soutrce: SNCP 2007

The open air combustion

The more alarming illegal practice associated with ELT disposal is, however, ‘open air combustion’ of tires.
The smoke produced by uncontrolled burning contains serious pollutants like aromatic hydrocarbons, sulphur compounds, carbon monoxide and nitrogen oxides.

The high temperatures reached during the fire cause also the decomposition of the rubber mix and the production of hydrocarbon oils of different molecular weight that facilitate the propagation of the fire.
The fire extinction can also be hazardous since chemical leaches can contain heavy metals in such a concentration as to pollute the underground layer.
This is the reason why landfill disposal has been progressively outlawed in Japan, North America and Europe.

OPPORTUNITY

Reuse, recycling or energy recovery instead of disposal?

As it was the case in the USA, the prohibition of landfi ll disposal of ELTs, introduced in Europe
by EC Directive 1999/31 and adopted in Italy with Italian Legislative Decree No 36/2003 has revolutionized the entire ELTs chain, favouring
the implementation of new recovery methods.

The Italian situation is different: even though approximately 48% of ELTs are used for energy recovery, the corresponding share of the real material recovery does not balance this ratio and there is still a high percentage (>25%) of material whose destination is uncertain.
In Italy every year 100 thousand tons of end of life tyres disappear unknown, according to a Legambiente report concerning the period 2005 to 2010.

Considering ELT as a resourxce not a waste


The European Union (EU) considers “waste minimization” the most desirable approach to a different method of treatment of the ELT waste management while “re-use”, “recycling” and “component recovery” of waste material are all more desirable than ultimate “disposal”.

RUBBER COMPOSITION OF CAR TIRES

SUBSTANCECAR TYRESTRUCK TYRES
NATURAL RUBBER41-43%34-35%
COAL38-32%36-32%
HYDROGEN6–7%5–6%
SULPHUR1–1,5%1–1,5%
IRON10–12%20–22%
FILLER3–4%3–4%
TYRE WEIGHT5–10 kg< 70 kg

THE VALUE OF ELT

COMPONENTSTIRE FOR PASSENGER CAR, WT %TIRE FOR TRUCK, WT %
NATURAL RUBBER2230
SYNTHETIC RUBBER2315
SOOT21,522
METAL16,525
FIBRE5,5-
ZINC OXIDE12
SULPHUR11
FILLERS7,55
JOINT CARBON MATERIALS7467
AVERAGE WEIGHT OF NEW TIRE8,5 KG65 KG
AVERAGE WEIGHT OF OLD TIRE7 KG56 KG
NET CALORIFIC VALUE30,2 MJ/KG26,4 MJ/KG
CARBON (C)69%61%
SULPHUR1,3%1,4%
Source: Scientific Journal of Riga Technical University Environmental and Climate Technologies 2010 Volume 4.

A DIFFERENT METHOD OF TREATMENT OF THE ELT

Here we will discuss one of the several methods of processing ELT to recover its basic components based on ‘non-combustion’ thermal technologies. This heating process which induces thermal degradation (depolymerization) of granular rubber compound in an inert environment is called “pyrolysis”.

The result of the pyrolysis process on ELT will be:
• The “char”, solid granular carbon with some impurities, which can be packaged for direct utilization or for further rocessing.

• The liquid phase, a mixture of combustible oils, which can be drummed for commercial use or utilized “at source” to fuel diesel/generator groups that can provide electricity to the processing plant and to the national electric grid.
• The third phase, a minor quantity of incompressible combustible gases, which will be “burned” in house, generally as a mean of disposal of the by-product.

Pyrolysis of rubber organic compounds in a temperature controlled environment will “crack” them into a solid fraction (Char) and a gaseous one which, through condensation, will yield a liquid phase and an incondensable gaseous phase.

How Pneus Gineo works
What is Pneus Gineo

The “Pneus Gineo” is a plant, based on a new proprietary design, to process ELT rubber in granular form via pyrolysis. The technology, developed by Get Energy Prime Italia, is being patented (Pyrolysis and diesel generator patent pending) is utilized to produce solid “char” and diesel grade combustible oil. .

Production capacity of Pneus Gineo 200

The plant PNEUS GINEO 200 is the basic system of the Get Energy Prime Italian.

The loading of the granules in the reactor is adjusted to 200 kg/hr.

The pyrolysis conditions for normal power, generate approximately 90 kg/hr of solid residue and 80 kg/hr of organic liquid. The remaining fraction of uncondensed gases is 30 kg/hr.

The diesel generator produces 200 kWe when it is powered by 40 L/hr of fuel, and then the loading of granules should be at least 100 kg/hr to obtain the maximum output from the generator. Of the 200 kWe available from the generator set, 50 kWe are disseminated to the pyrolysis system for own consumption.

The heat generated by the combustion of the pyrolysis gases not condensed (but not further used), is approximately 20 kWe.

Functionality of the Gineo system

The technology developed by Get Energy Prime Italia introduces a type of waste treatment and / or secondary materials alternative to landfills and incinerators.

To date, the Gineo system has achieved significant results with the treatment of end-of-life tires (ELT) and plastic materials, recovering the maximum energy content and producing alternative fuels and carbon residues. .

Description of the manufacturing process.

  • The waste and / or materials are introduced continuously into the pyrolysis chamber with a screw loading system.
  • The waste and / or materials will be heated in the reactor due to thermal induction and / or electrical resistance up to modulated temperatures. How much allows the splitting of solid matter into gas and carbonaceous matter..
  • The gas, due to its physical effect, rises towards the top of the reactor, is introduced into heat exchangers, which have the task of cooling the gas and transforming it into a liquid state.
  • The charcoal, (char) remains on the bottom of the reactor and through a screw, is discharged into a pipe, and fed directly into special containers.
  • The charcoal, (char) remains on the bottom of the reactor and through a screw, is discharged into a pipe, and fed directly into special containers.
  • Alternatively, the liquid can be used as an alternative fuel.

Management of the Plant

  • The system is 24 h monitored with on line data transmission through Internet and GPS to the main assistance centre ( data collected in real time allow to go on with production and operation)
  • Small size (low environmental impact)
  • Low noise level
  • Mobile plant
  • Full plant cogeneration
  • Very simple and rapid structure for maintenance and damage
  •  VAverage lifecycle of the plant: 18 years (with a regular maintenance)
  •  The plant is certifi ed according to European standards (EEC)
  •  • Generator certifi ed according to European standards (EEC)
  • The cleaning of the plant does not require the use of water ad thus is not polluting for ground and underground water

According to ENEL data, every kw of electricity produced in Italy generates on average emissions for 0.700 kg of co2

According to some statistical data, 1,650 kg of co2 are emitted per kg of fuel used in generators.

The Get Energy Prime Italia plants produce a bifuel that on average has a mass energy ratio of 1 to 3.3, that is 1 kg of fuel can develop 3.3 kw

Therefore 1,650 kg of co2: kw 3.3 = kg 0.500 co2 / kw

This quantity is further reduced by 35-40% with a catalytic system at the exit of the generators.

Therefore, Kg 0.500 co2 – 35% = KG 0.325 CO2 / KW

We can state that the difference in% of co2 compared to the national average is: kg 0.325 / kw: kg 0.700 / kw = 46.4%

Motor skills technical sheet
Tabella Motor GetEnrgyPrimeItalia EN
Conclusions

Business creation is not the result of “enlightenment”, but a decision that must be matured slowly.

To make a “good business”, you need: a good idea, a strong motivation and knowledge of the market.

The first objective is to reach a recycling society in which waste means a resource.

The Get Energy Prime Italia represents a valid alternative to the problem of recovering waste in maximum safety and above all in compliance with environmental regulations.