Tyre

Tyre Technical Proposal Design Philosophy The philosophy in the design of this recycling plant is to apply the very best technology available to produce a reprocessing system that is economically sound and will be able to support itself. At the same time the design and technology is such that the whole of the tyre is used to generate added value product and that no part of the tyre or process chemical is either discharged to the local environment or to landfill. Technology Approaches to Tyre Recycling Four key technological routes have been identified for the processing of 25,000 tonnes per annum of waste tyres into value added recyclate. These are, from low technology to high technology, granulate, and de-vulcanisation and thermo-set bonded composites. The use of pyrolysis technology will also be used to ensure that no residue from the proposed facility needs be discharged to landfill or other external waste disposal. Technologies Below are the technologies to be used for Tyres recycling, as proposed in the following diagram

Technologies of Tyre Recycling Processes (Zero Waste)

(1) (1) Mechanical Process

3 Mobile Shredding Stations

Dhafra Landfill

Mobile primary Shredding Station

Mobile primary Shredding Station

primary Shredding

Secondary Shredding

Stage1

Stage2

Mobile primary Shredding Station

Granulated 2 Stages + Separation

Waste wire +Waste fabrics

(2) Micronisation (2) Micronisation process

(4) De-Vulcanisation (3)De-Vulcanisation

(5) Pyrolysis (3)

Nanometric Technology

(4)

(5)

Thermo-Set

Pyrolysis

(De- vulcanisation)

Process

Char New Virgin Rubber Materials many 1000 ’s of Rubber products

Many High Value Products Constructions Industrials products

(Carbon Black)

Clean Steel

Mechanical Process This is a Physical Diminution process. All tyre reprocessing requires physical diminution to break down large tyres comprising of several closely integrated materials into smaller pieces that allow the release and separation of the various components that make up the tyre; rubber, steel, fabric. x

Shredding Two Stages The primary process is shredding, to tear the tyre into smaller pieces suitable for processing which is then followed by granulation, to separate out the various components (1)

Primary Shredding:-. The primary job of these units is to tear the whole tyre down to 100-200mm. The objective of this project is to implement up to date tyre management systems by carrying out all the primary shredding from stock piles. It will be more economical to transport the small pieces of tyre shred than a whole tyre. The final aim is to remove and recycle 100% of the waste tyres and clean the stock piles land fill areas and put in place a comprehensive up to date recycling. (2)

Secondary Shredding to tear tyre pieces to around 50mm

Granulation Granulation (crumbing process) is the standard technology solution, whose product, at this moment in time has the largest available market. Tyres pieces are processed further in more than one stage to separate the steel and fabric and the rubber is reduced and sized to granules in the range 1 to 10mm. This technology is relatively straightforward, well known with a ready market. The material is of relatively low value but is a precursor material for other technologies which add significant further value and consequently have a significant economic impact on the viability of the reprocessing plant, see below. This type of rubber crumb material has found very large use in applications such as sports field dressing, footpaths and playground surfaces and in non-critical road furniture uses such as bollards. As such there is a ready market and it is proposed that the reprocessing plant will have the facility to bag up such granulate for sale to the marketplace.

Materials Separation Steel Contaminated

Fabrics

Rubber Crumb

Figure 2 Separation of rubber, steel & fabrics from Mechanical process stage. Mechanical Process Diagram & Materials

Primary Shredding

Tyre Shredding System stage 1+2 to produce crumb rubber <20 mesh

Secondary Shredding

150 kW Capacity 4 to nn/hr Under 20 mm

Separation Zone

Metal by Magnet

Rubber

Baling Crumb Rubber Maximum size 20 mesh

Fibre

Collection For use

1 to 2 or 3 mm Crumb

Up to 5 or 10 mm Crumb

Figure; 3 complete layout plus the products expected from the Mechanical process

Micronisation process The Micronisation stage is designed to physically reduce the size of the rubber granulate (Crumb). Using patented Dena technology, the material is rapidly and efficiently reduced to microns size. The machinery used utilises an operating mode not previously seen in de-vulcanisation and rubber processing and allows the rubber to be reduced to the optimum size for the downstream processes. Furthermore, in the next following stage, Dena will provide a more advance technology to produce the nanometric range, required as part of the input to the de-vulcanisation technology (described below).

Micronisation process Plan

Interstage

Interstage Stock Stock

Crumb Rubber Micronisation Cascade

M1 M2 = Micronisation M3 reactors M4

M1 M2

M3

M4

180kW Capacity 2 tonne /hr Separation Screening = Pump Rubber in Microns size To Surface Preparation Figure; 4 complete layout of Micronisation process

Micronisated Rubber powder

Figure; 5 Fine rubber powders from Micronisation Process. Nanometric Process Route (De-vulcanisation) In most engineering applications, including tyres, soft, very elastic rubber is given additional strength and fixed in shape using a vulcanisation process. This process, also referred to as cross-linking, uses sulphur molecules to lock together the long chain proteins and other organics molecules that make up the rubber. This vulcanisation process is difficult to reverse and has not usually attempted a as part of the recycling of rubber from end of life tyres. This problem of de-vulcanisation has traditionally placed a strong technological barrier on the types of applications that recycled rubber can be used in. The application of a unique nanometric de-vulcanising technology to the rubber now opens up a large range of possibilities not previously available to rubber recyclers. The Dena technology has been used to design an integrated system for the reprocessing of end-of-life tyres, extracting and de-vulcanising the rubber component, suitable for reuse as a raw material for rubber products. This is a high-added value product. A double nanometric approach is taken. The use of patented micronising system turns rubber granulate into very small particles suitable for further processing in a unique mechano-chemical process which effectively breaks down the sulphur cross-links allowing the recyclate rubber to be used in all applications that the original virgin material can be used in. In addition Dena technology has been incorporated in the manufacturing method a closed system to ensure that there is no risk of the rubber or other materials being exposed to the environment, and vice versa, and that the process as a whole can be run without emissions or other discharges. The output of the de-vulcanisation system is a raw material which can be used for most engineering applications which require rubber. There is a large and ready market for such material, especially in the global facing manufacturing economies of China, India and Brazil. In addition the use of such material can help displace the manufacture of replacement synthetic rubbers which have oil as their feedstock. The easy recycling and reuse of such materials in a world of declining oil production will mean that market acceptance and demand for such materials can only increase in the short, medium and long term future. There are four main stages to produce the virgin like rubber materials, these unique processes based on the Dena technology are:-. Stage 3, Surface Preparation This unique process is designed to prepare the surface of the fine rubber powder (Micronised rubber) down to the nanometric zone, by reducing the particle size by several thousand times and therefore increasing the overall surface area of rubber available for chemical reaction ready for de-vulcanization.

The technique is primarily made up of high intensity shearing systems. Shear stresses, in excess of the shear strength of the rubber are applied. In combination with organic chemical accelerators (proprietary) and a small amount of pressure, this high shear reduces the rubber particles to less than 50µm. Residence time in this stage is around 15 minutes, during which the temperature of the rubber is gradually increased to around 80°C. Stage 4, Main De-Vulcanising Processing This is the main process in the system and is designed to breakdown the sulphur cross linked between the polymeric molecules. The De-vulcanisation process has not any harmful emission. In the de-vulcanising process, the material in this stage is heated to a temperature in the range 180200°C, which then allow Dena’s reactors technology to be utilises the in two ways. Firstly the intensifier works the rubber to help breakdown the structure and secondly is to allow a specially developed chemical cocktail to come into intimate contact with the rubber at the molecular level. These chemicals are primarily responsible for breaking the sulphur bonds within the rubber giving de-vulcanisation. This is achieved through a process of proton exchange at the polysulphidic cross linking groups. As the chemical reacts with a larger surface areas of the now micron sized rubber particles a Dena shearing processor removes this reacted surface to expose new rubber to the chemical. As the surface is sheared away the removed particles of rubber are further reduced in size down to the nanometric size to produce the new virgin like materials of high quality de-vulcanised rubber that has a high market value and demand. The residence time for stages 3 & 4 is around 11½ hours, with the material being constantly sheared throughout the process and particle size is reduced to the nanometric range. In the final stages the material can be blended in the usual way to give rubber appropriate for the particular application. As with most rubber precursor materials some formulation and/or cure adjustment may be required. We have the necessary data many of these applications. Material from the process is then packaged ready for sale and transport or produce a different types of rubber components.

(3) Nanometric De-Vulcanisation Surface Preparation

Chemical reagents. For surface preparation process of micronised rubber

Ch2 Surface preparation

Ch1

ch3

Ch -Dv = Chemical reagents for de -vulcanisation

tonne /hr Blending Control reactor

Surface Reactor 1

Rec ircul

Surface Reactor 2

Surface Reactor 3

Chdv 1

Surface Reactor 4

Chdv 2

n

Chdv 3

=

Chdv Mixture

Heating system DV -R e actor C hamber 1

DV -R e actor C hamber 2

DV -R eactor C hamber 3

DV -R eactor C hamber 4

Dena Reaction Chamber

Pump to final processing & packaging

Baling

Packing

Finish

Figure; 6 Nanometric Process (de-Vulcanisation) complete layout. Summary of Testing Results of Nanometric Processing Testing on the de-vulcanized material from the process has indicated that 95% of the original properties of the material are retained. INC. 2887 Gilchrist Road > Akron, Ohio, USA, has carried out the evaluation of the new virgin rubber materials. A full report is available. AKRON RUBBER DEVELOPMENT LABORATORY

Dena has many years experience in using such results to confirm the design of full scale plants based on its core technology, see the full plant of the De-vulcanisation of Nanometric Process below;

Additive

Nanometric Technology De-Vulcanisation –New Virgin Rubber No harmful emissions

Rubber Powder

Figure 7 Nanometric Process Line (de-Vulcanisation).

(1)NANO-METRIC De-Vulcanisation Process

Some Products Manufactured

(1)NANO-METRIC De-Vulcanisation

:

Road Furniture , Construction, Engineering Road Furniture

Ducting

Engineering

Household Goods £500 to 3000 per tonne

Figure; 8 Nanometric Process (de-Vulcanisation) different products can be made .

Thermo-set Bonding Route Introduction Rubber granulate has, for a long time, been used with resins, especially polyurethane technology old technique, to produce products such as traffic cones and bollards. The manufacturing method adopted for such products is usually restricted to manual or semi-automatic moulding processes. Such moulding techniques restrict the product shapes and forms which can be produced and also tend to prevent large pressures being used to consolidate product. As a result, the problem with such products is that they are inherently low strength with a tendency to be damaged easily. As such they cannot be used in circumstances in which the products are likely to be subjected to high stresses and where long term integrity is needed. Furthermore it is difficult to remove the resin from the product. This means that there is a limit to the number of times they can be recycled and reused before the amount of resin increases to the point where, once again, the structural integrity albeit low to begin with, is impaired excessively and the material cannot be reused. Thermo-set Technology To overcome all of these problems it is proposed to use a thermal bonding method to produce products using waste tyre rubber crumb mixed with a thermo-set materials (thermoplastic) as a binding agent. The thermo-set materials are mainly drive from waste too. The yield is different types of products produced by especially designed extruding system or injection moulding or rolling process. The ratio used to suit the finish products which they have desired properties and have several key advantages. These materials can be manufactured from 100% recycled tire rubber and thermal material with a variety of durable products. This extremely tough and durable material is easy to clean, which makes it perfect for floors, trailer, tiles, wood replacement for building, ports in extreme conditions. This material is stronger than other composites, is impervious to water, and is UV resistant. The boards made from it will not crack, rot, or split. So this material is an environmentally friendly and it can last longer. The material has also a natural choice for a number of specialized products too. Finally the products are easy to recycle again with the simple addition of heat. Both the rubber substrate and the thermoplastic material can be re-melted and remanufactured. There is very little restriction on the number of times this can be done given good control of both the original and recycling manufacturing process.

(4)Thermo-Set Intensification Process

Rubber Crumb Receiving & Storage

Fine

Medium

Coarse Thermal Waste Product

Mixer with Weight & Mixing Control System

Hot Extruding System

LAYOUT OF PROCESSING PLANT

Colouring Agent

Roller Cooling System

Cutting (to length) station

Packing & Palleting

Figure; 9 Thermo-set Process complete layout.

Some Thermo-Set Products

Household goods

•Dunnage composite •used as wood

Construction Application

Figure; 10 some products will be produced from Thermo-set Process.

This products are guarantee against chemicals, ultra-violet, petro.-chemicals, oils and seawater Sea Wall, Port

Figure; 11 some products will be produced from Thermo-set Process

PRODUCT MARKETS at UAE & Gulf Dubai Waterfront

Palm Islands

Port World

Figure 12, Shaw the potential markets in the UAE alone.

Pyrolysis

Pyrolysis for Removal of Rubber Contamination in Tyre Wire Dena Technology has developed a high efficiency pyrolysis process for the processing of end of life vehicle tyres It is proposed that such a pyrolysis process is used to remove rubber from wire removed from end of life tyres. The following represents the most basic process in which the wire is cleaned to add value and the products of the process are recycled back into the process or sold as produced without further processing. The process has been designed so that it consumes all of its own waste leaving no substances that give rise to additional disposal costs. One key issue with tyre recycling is disposal of both the steel and the fabric recovered from the tyres. The fabric is a waste product with very limited uses and frequently ends up being discharged to landfill. At around 5-7% by weight of the tyre and having a very large volume this is a potential problem in trying to design a zero waste solution to the problem of tyre recycling. Steel from shredding and granulation is usually contaminated with quantity of rubber due to incomplete separation and adherence of the rubber to the steel. This greatly reduces the selling value of the steel as scrap, because of the rubber residual with steel. A process with an installed target capacity of 2800 tonnes per year of clean wire is proposed and to produce 418 tonnes of char. The rubber contamination consists of approximately 65% organic compounds and 35% carbon filler. Pyrolysis process The contaminated Wire is charged to the pyrolysis furnace where it is subjected to temperatures in the range 450 to 700°C under anaerobic (that is oxygen free) conditions. This process causes the rubber to break down and the organic component of the oil is converted into a mixture of organic chemicals, primarily alkenes, and incompressible gasses. The complex mixture of organic chemicals has the potential to be used as a fuel or as a chemical precursor. The organic molecules it contains tend to be of relatively low molecular weight. The incompressible gases are primarily methane and hydrogen, again with a high calorific value and the potential to be used as fuel within the process. In this proposal the chemical mixture is recycled back in to the process to provide energy and to ensure that no additional waste arises. This process involves the thermal degradation in the absence of oxygen to the waste rubber on the steel and the fabric. The benefit of this application is the conversion of waste rubber into value-added products, mainly fuel oil, uncompressible gas and char (Carbon Black). In the case of tyre fabric this turns the material into fine carbon.

Then the tyre steel, in the Pyrolysis process will be removed mechanically from the steel leaving it clean and at full value as a recyclate for downstream processing. The carbon from both the rubber and the fabric can then be processed using Dena Technology particle size reduction equipment to provide technical char. Further processing can be used to convert this char into other useful products e.g. pigment, carbon black for new tyre or activated carbon, through the use of reactor at around 900°C in the presence of steam, after washing of the char by acid. The use of pyrolysis to process both the fabric and the steel adds considerable potential income to the processing plant and reduces to zero the waste from the process. The steel can be recovered and sold for full value, the residual rubber and fabric are converted into pyrolytic char and/or activated carbon which has a large use in and large value to the water treatment industry. This can product a high value product which can be used in the water treatment or other applications. Emissions The pyrolysis process is an inherently low emission system. However the system is designed with a scrubbing system with wet treatment to ensure that nothing escapes into the local environment.

Figure, 13; Pyrolysis diagram IN C O M P R E S S I B L E GAS

3 to n n e s p e r h o u r

C le a n S te e l

D ir t y S te e l (2 5 % R u b b e r)

P y r o ly s is L o w G ra d e C a rb o n

4 to n n e s p e r h o u r

SYNCRUDE

350kg per hour

S c h e m a t ic o f B a s ic T y r e W ir e P y r o ly s is P r o c e s s

Figure, 14; Pyrolysis layout

Pyrolysis Main Products STEEL High Value Clean Steel

Carbon & Char 1000-5000 / tonne (further processing)

Figure, 15; Products from Pyrolysis of clean steel & char (carbon black)