10 MT Tire Pyrolysis Technical Report

Technical proposal for 10TPD Scrap Tire Processing Unit

Technical Consultants: ACCPRE Engineering Pvt Ltd 8-2-601/B/22, Road No. 10, Banjara Hills, Hyderabad – 500034 Phone: +91 40 65810328

Accpre Engineering Pvt. Ltd.

8-2-601/B/22, Road No.10 Banjara Hills, Hyderabad-500034 Ph +9140-65810328



Contents 1.

INTRODUCTION............................................................................................................................... 2

2.

METHODS OF RECYCLING WASTE TIRES ......................................................................................... 4 2.1 RETREADING AND REUSING OF TIRES........................................................................................... 4 2.2 RECYCLING BY PRODUCTION OF GROUND RUBBER FOR USE IN OTHER APPLICATIONS ............. 4 2.3 RECLAIMING RUBBER RAW MATERIALS ....................................................................................... 5

3.

PYROLYSIS ....................................................................................................................................... 7 3.1 PROCESS CONDITIONS .................................................................................................................. 7 3.2 CHARACTERISTICS AND COMPOSITION OF THE PYROLYSIS PRODUCTS ....................................... 8 3.2.1 SOLID RESIDUE ....................................................................................................................... 8 3.2.2

PYROLYSIS LIQUID PRODUCT ........................................................................................ 10

3.2.3 STEEL WIRE........................................................................................................................... 10 3.2.4 PYROLYSIS GASES ................................................................................................................. 11 4.

EQUIPMENT STRUCTURE AND WORKING PRINCIPLE OF PYROLYSIS OF OIL EQUIPMENT ........... 12 4.1 DESCRIPTION OF THE PROCESS................................................................................................... 12 4.2

SPECIFICATIONS OF THE EQUIPMENT................................................................................... 14

4.3

UTLITIES OF THE PYROLYSIS SYSTEM .................................................................................... 14

ANNEXURE 1: PYROLYSIS PLANT LAYOUT ............................................................................................. 16 CONTACT INFORMATION ...................................................................................................................... 17

Accpre Engineering Pvt.Ltd.

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1. INTRODUCTION Over 9 million tones per year of scrap tires 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. A low percentage of scrap tires are recycled with material recovery and reused for second-quality rubber products. The problem is that waste tire generation rate is much more important than the amount of material required for these alternative uses. Because of their high calorific value, waste tires have been used as fuel in rotary cement kilns. However, this process can be acceptable from an environmental point of view only in the case of controlled combustion +due

to the toxic emissions produced during the tire combustion processes.


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The high volatile carbon content and heating value (33-35 MJ/kg) make the scrap tires an excellent material for energy recovery. For this reason, both pyrolysis and combustion are currently receiving renewed attention. Pyrolysis offers an environmentally attractive method to decompose a wide range of wastes, including waste tires. In the pyrolysis process, the organic volatile matter of tires (around 60 wt%) is decomposed to low molecular weight products, liquids or gases, which can be used as fuels or chemicals source. The non-volatile carbon black and the inorganic components (around 40 wt%) remain as solid residues and can be recycled in other applications. Combustion of tires has been used also for generation of electrical energy. However, for minimizing emissions the conditions of the combustion process must be optimized.


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2. METHODS OF RECYCLING WASTE TIRES

The possible ways of recycling waste tires are as follows:

2.1 RETREADING AND REUSING OF TIRES

In this process, the remaining tread is ground away from a tire to be remoulded and a new tread rubber strip is fused to the old carcass by vulcanization. The economic potential of the process is major advantage and the quality of the products is a disadvantage of retreading.

2.2 RECYCLING BY PRODUCTION OF GROUND RUBBER FOR USE IN OTHER APPLICATIONS

By mechanical or cryomechanical (cooling of rubber to a temperature ranging o

between 60 to 100 C) milling of tires the ground rubber of various sizes can be produced. These materials are used in other applications. For example: as component in asphalts, carpets, sport surfaces and children’s playgrounds. By

the cryomechanical technology it is possible to obtain a very fine powder, which can be used as reinforcement in new rubber products. Retaining of some properties of rubber materials and the absence of direct air emissions are the major advantages, However, the high consumption of energy, liquid nitrogen in the cryomechanical process and the limited market for the products are the main disadvantages of the process.


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2.3 RECLAIMING RUBBER RAW MATERIALS

Many attempts have been made since 1910 for reclaiming of scrap rubber products. However, rubber products during the processing and moulding are crosslinked, and therefore they cannot be again softened or remoulded by heating. Reclaiming of scrap rubber products means the conversion of a three dimensionally interlinked, insoluble and infusible strong thermoset polymer to a two dimensional, soft, plastic, processable and vulcanizable polymer simulating many of the properties of virgin rubber. In this case reclaiming of scrap rubber is more complicated than reclaiming of thermoplastics. Various methods and processes for reclaiming waste rubber were developed. The most important of them are: the mechanical shearing process, thermomechanical reclaiming, reclaiming by use of various chemical agents, microwave reclaiming, ultrasonic reclaiming, pyrolysis of waste rubber, reclaiming by renewable resource materials and reclaiming by biotechnological process. The main problem which reclaim producers face is the acceptability of reclaim by rubber industry as a raw material. This depends upon two major factors: - The quality of reclaim products measured by their properties compared to the properties of virgin raw materials, - The cost of reclaim compared to the cost of virgin rubber. Of all the reclaiming processes pyrolysis of tyres is receiving renewed attention because of the commercial value of the products obtained from the process.


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ADVANTAGES OF WASTE TYRE PYROLYSIS PROCESS OVER OTHER RECYCLING PROCESSES.

•100% waste tire recycling is achieved (no churn left after the process). •No chemical ingredients are used in process (environment friendly). • During and after the process; no soil, water or air pollution is observed. •Creates economically valuable products out of waste (all of the products are

industrial raw materials that have a market value). • The most cost-effective waste tire recycling technology in the world. • The system is applicable for the waste tire components (rubber dough, used

rubber, granulated rubber, etc.) which are the by-products of tire production. •Each recycled ton of tire preserves 10 tons of CO2 that is a major greenhouse

gas. •The process can be applied to all rubber based materials. •The system creates an alternative source of energy to replace petroleum

products and natural gas. •System gives the opportunity to governments and local administrations to

deal with the waste tire problem to a great extent. •System prevents the spread of diseases caused by waste tires.


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3. PYROLYSIS

Tire pyrolysis (thermal decomposition in an oxygen-free environment) is currently receiving renewed attention. Recycling of tires by pyrolysis offers an environmentally attractive method. The products of the tire pyrolysis process are: Solid residue (30-35 wt%), liquid residue (40-45 wt%), scrap steel (10-15 wt%) and gases (10-15 wt%). The solid residue contains carbon black and the mineral matter initially present in the tire. This solid residue may be used as reinforcement in the rubber industry, as activated carbon or as smokeless fuel. The liquid product consists of a very complex mixture of organic components. Thus, the derived oils may be used directly as fuels, petroleum refinery feedstock or a source of chemicals. The gaseous fraction is composed of noncondensable organics as, H2, H2S, CO, CO2, CH4, C2H4, C3H6 etc. The gas fraction can be used as fuel in the pyrolysis process.

3.1 PROCESS CONDITIONS

Pyrolysis of waste tires leads to the production of a solid carbon residue (char), a condensable fraction (pyro-oil) and gases. The percentage of each phase is influenced by process conditions, such as temperature, pressure, heating rate, particle sizes, heat exchange system, catalysis etc. Pyrolysing waste tire at a o

o

-1

temperature between 300 and 720 C and heating rates 5 and 80 C min found o

that the maximum conversion of tire occurred at a temperature of 600 C found that the temperature does not significantly influence the char and gas yields o

over 500 C. However, temperature variations influence the gas composition Accpre Engineering Pvt.Ltd.

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pyrolysed cross-section samples (2-3 cm wide), representative of whole tire, at o

300-700 C. Tire-pyrolysis liquids are a complex mixture of hydrocarbons, which contains 0.4% of N and 1.2% of S.

3.2 CHARACTERISTICS AND COMPOSITION OF THE PYROLYSIS PRODUCTS

Use of pyrolysis as a method for recycling waste tire depends on the market for pyrolysis products. For this reason, characterization of pyrolysis products and possibilities of their application in other processes is very important. At present time, the main application for solid char is its use as active carbon, as reinforcement in rubber industry and as smokeless fuel. The liquid product is used as a fuel, or a source of chemicals, scrap steel can be melted and with some additives it can be used as normal steel & the gas fraction as a fuel in the pyrolysis process. Quantity of the products produced is given in table below. Products

Weight %

Crude oil

40-45

Carbon black

30-35

Scrap steel

10-15

Gases

10-15

3.2.1 SOLID RESIDUE

Carbon Black is one of the main products recycled by pyrolysis technology. The amount of recycled carbon black is 30-35% (depending on the type of tire) of the total amount of scrap tire recycled in the system. Carbon black is used as Accpre Engineering Pvt.Ltd.

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raw material or main ingredient in many industries and the chemical structure of carbon black strengthens, lengthens the endurance, and improves the coloring features of the materials. Carbon black produced by pyrolysis application is more economical compared to carbon black produced primarily from petroleum and is more price-efficient to be used as an ingredient in the industries listed; 1) Electric cable jacketing 2) Conveyor band 3) Carrier Bands 4) Hose and doormat 5) Black nylon bag 6) Rubber additive 7) Automotive spare parts 8) Heat isolation 9) Black colorant in rubber materials Elemental analysis of pyrolysis solid residue (carbon black) Weight %

Element

71

Carbon

13.3

Oxygen

5.4

Iron

2.8

Sulphur

2.3

Zinc

1.3

Calcium

0.3

Aluminium


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3.2.2 PYROLYSIS LIQUID PRODUCT

The liquid phase is the most important product of tire pyrolysis process. Gas chromatography/Mass spectroscopy (GC/MS) is the method for analysing pyrolysis liquid product, but also for analysing the gas yield and products of char combustion. Pyrolysis oil contains a lot of aromatics (53.4 –74.8%), some nitrogenated (2.47 –3.5%) and some oxygenated compounds (2.29 –4.85%). Their GCV 10,000kcal/kg is even higher than that specified for commercial heating oils, but the sulphur content (1 –1.2%) is close to or slightly below the limit value. Significant quantities of valuable light hydrocarbons such as benzene, toluene, xylene, limonene, etc. were obtained. The concentration of these compounds increases with temperature up to 500°C and then decreases. There is also an important portion of polycyclic aromatics, such as naphthalenes, phenanthrenes, fluorenes, diphenlys, etc.; their concentration as well as that of total aromatics increase significantly with temperature. This oil typically contains 20-25 wt% of naphtha fraction with a boiling point lower o

than 200 C. The naphtha fraction typically contains 20-25 wt% dl- limonene.

3.2.3 STEEL WIRE

Tires contain steel wires and the amount ranges from 10%-15% of the total tire weight. All of the steel present in the tire can be detached after the pyrolysis recycling process is completed. Valuable steel wires are pressed and sold to steel and scrap dealers.


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3.2.4 PYROLYSIS GASES

The pyrolysis gases contains CO, CO2, H 2S and hydrocarbons such as CH4, C 2H4, C3H6 and C4H8, and their unsaturated derivatives. Non-Condensable gasses arise during the recycling application which; •Has a higher calorific value compared to natural gas •Can replace natural gas and propane when stored •Can be used as energy resource in gas burners, also used in pyrolysis system

The amount of gas generated in the system is 10%-15% of the total amount of recycled tires and considering the 10 ton scrap tire/day recycling capacity, the facility generates 900-1000 m³/day gas which has an enormous energy potential when evaluated.


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4. EQUIPMENT STRUCTURE AND WORKING PRINCIPLE OF PYROLYSIS OF OIL EQUIPMENT

The Equipment is composed of nine parts: 1) Reactor 2) Emissions Scrubber System 3) Feeding-in system. 4) Dedusting System. 5) Condensation system. 6) Storage oil System. 7) Fuel gas heating system (waste gas processing system). 8) Carbon black slag system. 9) Flue dust removal system.

4.1 DESCRIPTION OF THE PROCESS

The pyrolysis reactor is a horizontal type revolving split processor which rotates on a horizontal axis. It is a two walled reactor, inside the first wall it is filled with scrap rubber tyres with the help of feeding in system and between the first and second wall it is filled with fuels like coal, wood, unliquefied gas. The Reactor has an adjustable rotation rate from 0.4-0.8 rpm. The reactor is heated externally. Sealing of reactor is a difficulty technology, especially for a Accpre Engineering Pvt.Ltd.

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pyrolyser. The internal pressure of the reactor is higher than atmospheric pressure. A special friction-type seal was designed and successfully applied to the pyrolysis system with high temperature. But the use of rotary reactor is advantageous for other pyrolysis technologies. Solid wastes with different shapes, sizes, and heating values can be fed into the reactor in batches or continually. The Reactor is loaded with tyres and heated up by the fuel under it. The scrap tires will get converted to gases which is a complex mixture of hydrocarbons 0

and slag when it heated up to a temperature of 700 C in the reactor. The exhaust gases at 5500C will be transmitted by the pipe on the top of the cracking reactor to the scrubber where impurities such as ash are removed from the exhaust gas. The cleaned exhaust gas is then sent to a dedusting system where the minute impurities are cleaned off before the gas is sent to condensing system. In the 0

condensing system the gases are cooled to 60 C. The condensation of the gases is done by the heat exchange. The liquid part of the gases is condensed to crude oil. Liquid crude oil will be delivered to the storage tank and the unliquefied exhaust gases are transported to exhaust gas recycle system which transports the gases to the bottom of the cracking reactor and used as a fuel to heat up the cracking reactor. The carbon black and the steel wire in the reactor are transmitted out with the help of carbon black slag system.


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4.2 SPECIFICATIONS OF THE EQUIPMENT Equipment model

YL-10

Raw material

Waste tyres

Structure form

Horizontal type

Daily handling raw material

10 tons

Reactor rotating speed

0.4-0.8RPM (adjustable)

Power

11 KW

Cooling mode

Water

Consumption of cooling water

0.4ton/day

Coal consumption

0.4 tons/day

Heating mode

Direct

Noise dB (A)

<85

Reactor dimensions(mm)

D2800*L6600

Working mode

Intermittent

Weight of the reactor

12T

4.3 UTLITIES OF THE PYROLYSIS SYSTEM Power

11KW

Space

30*20m

Coal consumption per day

0.3 tons


2

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TIRE PYROLYSIS OIL PROPERTIES Test Density Flash point 0 Viscosity @ 40 C Conradson carbon residue Asphaltine content Ash content Pour point Sulphur content Water by distillation Calorific value Distillation at 1atm IBP 05% Recovery 10% Recovery 20% Recovery 30% Recovery 40% Recovery 50% Recovery 60% Recovery 70% Recovery 80% Recovery 90% Recovery


Unit g/cc 0 C 2 mm /s %wt %wt %wt 0 C %wt %vol Kcal/kg

0

C

Results 0.9 40 6 0.2 0.47 0.001 -21 0.3083 0.05 10500 50 80 115 141 163 187 225 260 294 340 364

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ANNEXURE 1: PYROLYSIS PLANT LAYOUT

PLANT LAYOUT


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CONTACT INFORMATION Raghuvardhan Reddy Suram Mechanical Engineer, Accpre Engineering Pvt.Ltd Phone :+91-7702623926 [email protected]


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10 MT Tire Pyrolysis Technical Report

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