Indian Patents. 278033:A METHOD OF CONVERSION OF WASTE RUBBER AND TYRE TO FUEL

Title of Invention	A METHOD OF CONVERSION OF WASTE RUBBER AND TYRE TO FUEL
Abstract	The present invention relates to a method and an apparatus for the conversion of waste rubber and used tyres to fuel.

Full Text	FIELD OF THE INVENTION The present invention relates to fuels. Particularly, the present invention relates to alternative fuels. BACKGROUND OF THE INVENTION & PRIOR ART The recent energy crisis has created havoc in the world. The demand for fuel for industrial and domestic purposes, automobiles and the like is increasing at an alarming rate. With limited resources at hand, meeting the demand at an affordable price seems to be next to impossible. At this crucial juncture, the need for finding alternative fuel is of utmost importance. Alternative fuels, also known as non-conventional fuels are substances that can be used as a fuel, other than conventional fuels. Conventional fuels include fossil fuels (petroleum (oil), coal, propane, and natural gas), and nuclear materials such as uranium. Some well known alternative fuels include biodiesel, bioalcohol (methanol, ethanol, butanol), chemically stored electricity (batteries and fuel cells), hydrogen, non-fossil methane, non-fossil natural gas, vegetable oil and other biomass sources. Waste rubber material is the most routine form of hydrocarbon-containing polymer materials. Used tyres of vehicles and, especially, metal-cord tyres are presently the principle source of waste rubber materials. It is generally known that waste rubber materials can serve as a source of valuable recycled resources. However, the recovery of valuable resources is generally impeded by high strength of chemical bonds in macromolecules of vulcanized rubber. Several efforts have been made in the prior art to harness the energy trapped in such waste materials. United States Patent 5,894,012 discloses a method and system for recovering marketable end products from waste rubber. The processing system pyrolyzes waste rubber to produce pyrolysis oil and carbon black and then purifies and refines these end products to broaden their commercial applications and to increase their market value. United States Patent 5,976,484 discloses an intermittent continuous method for recovery of refined activated carbon from waste tires and the like and the device therefor. The method involves a series of heating, dry distillation and splitting decomposition. United States Patent 6,743,746 discloses a catalyst for the low-temperature pyrolysis of hydrocarbon-containing polymer materials mainly intended for use in the recycling of rubber waste materials. The catalyst is prepared from a carbon-iron component in the form of microscopic carbon particles and ultra-dispersed iron particles. The catalyst further contains a metal-carbon component. United States Patent 6,538,166 discloses a process and apparatus for treatment of Waste rubber. The process includes heating a quantity of rubber in an atmosphere at a negative pressure and at a temperature between 340 Celsius and 510 degrees Celsius such that the rubber is vaporized and defines a vaporized rubber. The vaporized rubber has a plurality of hydrocarbon constituents therein. A venturi separator sprays the vaporized rubber with oil having a boiling temperature greater than 175 degrees Celsius. The oil binds to heavy oil in the hydrocarbon constituents. A remaining portion of the vaporized rubber is condensed such that light oils in the hydrocarbon constituents liquefy and are separated from hydrocarbon gases. United States Patent Application 20060265954 discloses a gasifier for the gasification of biomass and waste to produce combustible effluent, producing combustible gases for energy generation. United States Patent Application 20050023124 discloses a pyrolytic conversion process of scrap tires to carbon products. A char containing less than 5% volatile matter is produced by pryolyzing shredded scrap vehicle tires and other rubber scrap material in an externally heated retort until the rubber is completely decomposed and until the temperature of the gases produced by the pyrolysis process reaches at least 500 degree C. United States Patent 5,744,668 discloses a process of producing gasoline, diesel and carbon black with waste rubbers and/or waste plastics. The process comprises pyrolysis, purifying, catalytic cracking, and fractionation. International Application No.: PCT/PL2004/000081 discloses a method and a device for continuous conversion of organic waste, in particular, highly contaminated waste plastics and worn out vehicle tyres. The methods and the devices disclosed in the prior art are tedious, labour-intensive and time consuming. Further, the disclosed methods are not cost-effective. In addition, most of the known methods and means for rubber destruction are dangerous because of the environmental contamination with sulfur compounds, carcinogenic carbon black and certain other toxic substances. Thus, an efficient, safe and economic method of conversion of waste rubber and tyres into fuel is the need of the hour. OBJECTS OF THE INVENTION It is an object of the present invention to provide an alternative fuel. It is another object of the present invention to provide an alternative fuel using waste rubber and used tyres as starting material. It is yet another object of the present invention to provide a method for the conversion of waste rubber and tyres to fuel. It is still another object of the present invention to provide a method which is simple and efficient for the conversion of waste rubber tyres to fuel. It is still another object of the present invention to provide a method of conversion which is less time consuming. It is still another object of the present invention to provide a method of conversion which is not labour-intensive. It is still another object of the present invention to provide a method of conversion which is cost-effective. It is still another object of the present invention to provide a solution for the mounting problem of disposal of waste rubber and used tyres. STATEMENT OF THE INVENTION Accordingly, the present invention relates to a method of conversion of waste rubber material to fuel, said method comprising the following steps: i) heating the waste rubber material at a temperature ranging from about 300°C to about 500°C in the presence of a catalyst in a reactor to obtain gaseous products; ii) collecting said gaseous products; and iii) cooling the collected gaseous products by passage through cooled pipelines maintained at 5-30°C and collecting condensed gaseous products. Typically, the waste rubber material is waste tyre, shredded into pieces of about 20mm size. Typically, said reactor is preferably a twin naked stainless steel cylindrical container having inner diameter of about 205 mm, outer diameter of about 210 mm and height of about 437 mm. Typically, said catalyst is at least one catalyst selected from a group comprising aluminium silicate, barium silicate, beryllium silicate, calcium silicate, iron silicate, magnesium silicate, manganese silicate, potassium silicate, sodium silicate, zirconium silicate, copper silicate, tin silicate, iron silicate, lead silicate, tungsten silicate, cesium silicate lithium silicate, aluminium, bismuth, copper (cuprum), iron (ferrum), lead, magnesium, manganese, nickel, tin (stannum), tungsten, zinc, aluminium oxide, bismuth oxide, copper (cuprum) oxide, iron (ferrum) oxide, lead oxide, magnesium oxide, manganese oxide, nickel oxide, tin (stannum) oxide, tungsten oxide, zinc oxide, aluminium carbonate, calcium carbonate, sodium carbonate, bismuth carbonate, copper (cuprum) carbonate, iron (ferrum) carbonate, lead carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, tin (stannum) carbonate, tungsten carbonate, zinc carbonate, silicone carbide, calcium carbide, natural and synthetic zeolite, alumina, fuller's earth, bauxites, metal borates and metal borides. Typically, said catalyst comprises about 10-80% silicate, about 0.001-50% zeolite, about 0.001-10% transition metal, about 0.001-40% metal oxide, about 0.001-10% metal borate, about 0.001-10% metal carbonate, about 0.001-50% fuller's earth, about 0.001-10% metal carbide, about 0.001-10% metal boride, about 0-10% activated charcoal, about 100% NiW loaded on amorphous silica-alumina, about 100% NiMo over gamma alumina, about 100% WC and Ni on carbon sheet, about 100% Ni octanate, about 100% cobalt on activated carbon, about 100% nano materials of alpha alumina 30-150 nm, about 100% gamma alumina 40-80 nm, and about 100% nano zinc 90-200 nm. Typically, said catalyst has a particle size ranging from about 0.1 mm to about 10 mm. Typically, said catalyst is introduced at a concentration ranging from about 0.001 to about 10% of the total mass of reactants in the reactor, preferably about 1 - 4%. Typically, the heating of the waste rubber material is preferably carried out at a temperature ranging from about 350°C to about 450°C. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS The invention will now be described with reference to the accompanying drawings in which: Fig. 1 describes the pyrolysis reactor for large scale operation in accordance with this invention, generally indicated by the reference numeral 100. The reactor is made of stainless steel with the capacity to convert about 10 Kg of waste rubber and used tyres. The reactor is cylindrical in shape with the inner diameter of 205 mm and outer diameter of 210 mm. The height of reactor is 437 mm and with the support the height is 586 mm. The height of the total reactor including magnetic stirrer and stand is 746 mm. Shredded rubber and catalyst are charged into a Distillation flask 37 with heating mantle 34. The Distillation flask 37 is sealed and sludge drain 15, washer thermocouple 36, catalyst baffle 33, insulation jacket 35, safety valve 18, stirring mechanism 31 and a fume outlet 29 connected to cold water condenser 26 running cold water from inlet 25 to outlet 27. The liquid condensed is collected in receiver vessel 23 placed in an ice bath and having drain valve 21, level indicator 22, pressure gauge 24 and is connected to vacuum pump 17 by silicon tubing 16 through a vacuum valve 20. The receiver vessel 23 is fitted with safety valve 18 through silicon tubing 16 to a secondary glass vessel of 2 litres for the collection of highly volatile gases. After the addition of the waste material in the reactor, all valves are closed and air removed from the system with the help of a vacuum pump. Fig. 2 illustrates the receiver vessel 23 in accordance with this invention which collects the condensed gaseous products. Fig. 3 illustrates the distillation flask 37 in accordance with this invention. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of conversion of waste rubber material to fuel, said method comprising the following steps: i) heating the waste rubber material at a temperature ranging from about 300°C to about 500°C in the presence of a catalyst in a reactor to obtain gaseous products; ii) collecting said gaseous products; and iii) cooling the collected gaseous products by passage through cooled pipelines maintained at 5-30°C and collecting condensed gaseous products. In accordance with this invention, the waste rubber material is waste tyre, shredded into pieces of about 20mm size. In accordance with the present invention, said reactor is preferably a twin naked stainless steel cylindrical container having inner diameter of about 205 mm, outer diameter of about 210 mm and height of about 437 mm. In accordance with another embodiment of the present invention, said catalyst is at least one catalyst selected from a group comprising aluminium silicate, barium silicate, beryllium silicate, calcium silicate, iron silicate, magnesium silicate, manganese silicate, potassium silicate, sodium silicate, zirconium silicate, copper silicate, tin silicate, iron silicate, lead silicate, tungsten silicate, cesium silicate lithium silicate, aluminium, bismuth, copper (cuprum), iron (ferrum), lead, magnesium, manganese, nickel, tin (stannum), tungsten, zinc, aluminium oxide, bismuth oxide, copper (cuprum) oxide, iron (ferrum) oxide, lead oxide, magnesium oxide, manganese oxide, nickel oxide, tin (stannum) oxide, tungsten oxide, zinc oxide, aluminium carbonate, calcium carbonate, sodium carbonate, bismuth carbonate, copper (cuprum) carbonate, iron (ferrum) carbonate, lead carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, tin (stannum) carbonate, tungsten carbonate, zinc carbonate, silicone carbide, calcium carbide, natural and synthetic zeolite, alumina, fuller's earth, bauxites, metal borates and metal borides. In accordance with another embodiment of the present invention, said catalyst comprises about 10-80% silicate, about 0.001-50% zeolite, about 0.001-10% transition metal, about 0.001-40% metal oxide, about 0.001-10% metal borate, about 0.001-10% metal carbonate, about 0.001-50% fuller's earth, about 0.001-10% metal carbide, about 0.001-10% metal boride, about 0-10% activated charcoal, about 100% NiW loaded on amorphous silica-alumina, about 100% NiMo over gamma alumina, about 100% WC and Ni on carbon sheet, about 100% Ni octanate, about 100% cobalt on activated carbon, about 100% nano materials of alpha alumina 30-150 nm, about 100% gamma alumina 40-80 nm, and about 100% nano zinc 90-200 nm. In accordance with another embodiment of the present invention, said catalyst has a particle size ranging from about 0.1 mm to about 10 mm. In accordance with another embodiment of the present invention, said catalyst is introduced at a concentration ranging from about 0.001 to about 10% of the total mass of reactants in the reactor, preferably about 1 - 4%. In accordance with another embodiment of the present invention, heating of the waste rubber material is preferably carried out at a temperature ranging from about 350°C to about 450°C. In accordance with another embodiment of the invention, air is removed from the reactor to create vacuum at the start of reaction. Typically, a tyre comprises about 40% rubber, about 15% steel, about 5% textile fabrics, about 25% soot and about 15% chemical compounds. The present invention provides an effective and highly efficient process for the conversion of waste rubber material into fuel. Typically, the process is suitable for being carried out on a large scale. The special method, conducting the decomposition reactions catalytically in the presence of a novel and inexpensive catalyst provides a control over the temperature of the liquid fraction, and greatly improves the efficiency of the process and the quality of the final product. The catalyst is introduced at a ratio ranging from about 0.01:1 to about 0.10:1 of the total mass of reactants in the reactor. As the quantity of catalyst is increased with the proportion of the total mass, the total reaction time is reduced and the yield is more. As the temperature of the reaction is increased the yield percentage is more. Typically, 80% of the product is obtained at 390°C. The decomposition product, in the form of gaseous and liquid mixture of smaller hydrocarbons is suitable to be recycled as raw material for polymers or liquid fuels or other chemical industry processes or serves directly as fuel for combustion engines, e.g. electric generators boilers, raw material for petroleum industry, bunker fuel and the like. The solid product obtained in the reactor is coke which can be used as fuel for thermal power plants and metallurgical industries. As described in the figures 1-3, the present invention concerns also a device for conversion of waste rubber material into fuel, said device containing a housing (reactor), a heating system and a product collecting system. The charge of waste, say shredded tyre of about 20 mm size is introduced into the reactor having a hot bath whose temperature is maintained at about 300-500°C, preferably about 350-450°C. The catalysts are added at this stage to hasten the process of pyrolysis. The gaseous products of the decomposition are collected at the top and cooled by passing through pipes maintained at about 5-30°C. A reservoir maintained at 0°C stores the condensed product which is used as fuel. During the reaction, the molecules of rubber pieces penetrate the structure of the catalyst and absorb on the active areas to react. A catalyst of this type has the advantage of presenting a large reactive surface and it also provides better reaction selectivity. A large pore catalyst is used for catalytic cracking which allows the largest molecules access to the active areas. The catalyst also serves to increase the rate of forward reaction and minimize the temperature of the reaction. Typically, about 200 ml of heavy oil is added along with the catalyst. A typical catalyst composition in accordance with this invention along with the respective optimum temperatures for the conversion of waste rubber material including used tyres into fuel is provided in Table 1. A typical combination of the catalysts added at specific ratios to the waste rubber material and the yield of the fuel generally expected is tabulated in Table 2. Table 2: Catalyst Ratio and the expected yield Further, the novel construction of the housing as described in the present invention ensures right isolation and at the same time gives easy access to the interior of the device. The novel construction of the heating system allows to fully utilize the heat energy and its supply to the whole volume of the reaction mixture. It provides a control over the temperature of the liquid fraction and prevents the reaction mass and impurities from entering into the cooling pipes which ensures long life of the bath. The method and the device according to the present invention have been realized on industrial scale. According to the present invention, the process of catalytic conversion takes place continuously. The thermo-catalytic reactions in the reaction vessel do not require high pressure or addition of hydrogen. The catalyst is cheap and the spent catalyst can be recycled 1 to 2 times. Only one heating source is used in the technological production line. The product is of high quality and the by-product is potentially useful as wax for starting material for candle production. The total time for the completion of reaction ranges from 1.5 to 3 hours, which is visibly indicated by stopping of liquids being collected in the receiver vessel. Typically, the yield of the products obtained in accordance with this invention is as follows: Liquid hydrocarbon: 40 - 60%; Solid coke: 40-50%; and Gas: 5 - 20% The invention is further elaborated with the help of following examples; however, these examples should not be construed to limit the scope of the present invention. EXAMPLE 1: 5 kg of waste rubber tyre was introduced into the reaction chamber of the device provided in accordance with this invention. To this, 0.09 kg of silicates and 0.01 kg of charcoal was added and the mixture was heated at 400°C. The gaseous products evaporating from the heated mixture were collected and passed through cooling pipes maintained at 15 °C. The condensed product was stored in the reservoir maintained at 0 °C. The yield obtained was as follows: Liquid hydrocarbon - 50% Gas-10% Solid coke-40%. EXAMPLE 2: 6kg of used car tyre shredded into pieces of about 20mm was introduced into the reaction chamber of the device provided in accordance with this invention. To this, 0.05 kg of silicates, 0.05 kg of zeolite and 0.05 kg of fuller's earth along with 200 ml of heavy oil was added and the mixture was heated at 410°C. The gaseous products evaporating from the heated mixture were collected and passed through cooling pipes maintained at 15 °C. The condensed product was stored in the reservoir maintained at 0 °C. The yield obtained was as follows: Liquid hydrocarbon - 46 % Gas-7% Solid coke-47%. EXAMPLE 3: 10 kg of waste rubber was introduced into the reaction chamber of the device provided in accordance with this invention. To this, 0.128kg of silicates, 0.032 kg of metal oxide, 0.032 kg of carbonate and 0.128 kg of fuller's earth along with 200 ml of heavy oil was added and the mixture was heated at 360°C. The gaseous products evaporating from the heated mixture were collected and passed through cooling pipes maintained at 15 °C. The condensed product was stored in the reservoir maintained at 0 °C. The yield obtained was as follows: Liquid hydrocarbon - 53% Gas-7% Solid coke-40%. EXAMPLE 4: A typical liquid fuel i.e., petroleum product obtained in accordance with this invention on analysis gave the following results: • Colour and Appearance: Light brown coloured oily liquid. • Flash point (Abel's): 5 °C • Sulphur content: 0.06% • Pour point: Below minus 33 °C • Distillation Range: a) Initial boiling point: 85°C b) 2% by volume distilled at 92 °C c) 5% by volume distilled at 112 °C d) 10 % by volume distilled at 130 °C e) 20 % by volume distilled at 148 °C f) 30% by volume distilled at 165 °C g) 40% by volume distilled at 273 °C h) 50% by volume distilled at 290 °C i) 60% by volume distilled at 300 °C j) 70% by volume distilled at 310 °C k) 80% by volume distilled at 315 °C • Kinematic viscosity at room temp. (30 °C): 7.69 est. • Density at 15 °C: 0.81009 gms/ml • Gross calorific value: 10765 cal/gm 19377 Btu/lb • Custrip corrosion for 3 hrs. at 50 °C: Negative TECHNICAL ADVANCEMENT The instant invention offers several technical advancements and advantages as mentioned below: • The method of conversion of waste rubber and used tyres to fuel disclosed in this invention is simple and effective. • The disclosed method is less time consuming. • Further, the method of conversion provided in the instant invention is not labour-intensive. • The method provided in the instant invention is economic. • The disclosed method provides an effective solution for the energy crisis encountered in the contemporary world. • The disclosed method also provides an effective solution for the mounting problem of disposal of waste rubber and used tyres. While considerable emphasis has been placed herein on the various components of the preferred embodiment, it will be appreciated that many alterations can be made and that many modifications can be made in the preferred embodiment without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. I Claim: 1. A method of conversion of waste rubber material to fuel, said method comprising the following steps: i) heating the waste rubber material at a temperature ranging from about 300°C to about 500°C in the presence of a catalyst in a reactor to obtain gaseous products; ii) collecting said gaseous products; and iii) cooling the collected gaseous products by passage through cooled pipelines maintained at 5-30°C and collecting condensed gaseous products. 2. The method as claimed in claim 1, wherein the waste rubber material is waste tyre, shredded into pieces of about 20 mm size. 3. The method as claimed in claim 1, wherein said reactor is preferably a twin naked stainless steel cylindrical container having inner diameter of about 205 mm, outer diameter of about 210 mm and height of about 437 mm. 4. The method as claimed in claim 1, wherein said catalyst is at least one catalyst selected from a group comprising aluminium silicate, barium silicate, beryllium silicate, calcium silicate, iron silicate, magnesium silicate, manganese silicate, potassium silicate, sodium silicate, zirconium silicate, copper silicate, tin silicate, iron silicate, lead silicate, tungsten silicate, cesium silicate lithium silicate, aluminium, bismuth, copper (cuprum), iron (ferrum), lead, magnesium, manganese, nickel, tin (stannum), tungsten, zinc, aluminium oxide, bismuth oxide, copper (cuprum) oxide, iron (ferrum) oxide, lead oxide, magnesium oxide, manganese oxide, nickel oxide, tin (stannum) oxide, tungsten oxide, zinc oxide, aluminium carbonate, calcium carbonate, sodium carbonate, bismuth carbonate, copper (cuprum) carbonate, iron (ferrum) carbonate, lead carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, tin (stannum) carbonate, tungsten carbonate, zinc carbonate, silicone carbide, calcium carbide, natural and synthetic zeolite, alumina, fuller's earth, bauxites, metal borates and metal borides. 5. The method as claimed in claim 1, wherein said catalyst comprises about 10-80% silicate, about 0.001-50% zeolite, about 0.001-10% transition metal, about 0.001-40% metal oxide, about 0.001-10% metal borate, about 0.001-10% metal carbonate, about 0.001-50% fuller's earth, about 0.001-10% metal carbide, about 0.001-10% metal boride, about 0-10% activated charcoal, about 100% NiW loaded on amorphous silica-alumina, about 100% NiMo over gamma alumina, about 100% WC and Ni on carbon sheet, about 100% Ni octanate, about 100% cobalt on activated carbon, about 100% nano materials of alpha alumina 30-150 nm, about 100% gamma alumina 40-80 nm, and about 100% nano zinc 90-200 nm. 6. The method as claimed in claim 1, wherein said catalyst has a particle size ranging from about 0.1 mm to about 10 mm. 7. The method as claimed in claim 1, wherein said catalyst is introduced at a concentration ranging from about 0.001 to about 10% of the total mass of reactants in the reactor, preferably about 1 - 4%. 8. The method as claimed in claim 1, wherein the heating of the waste rubber material is preferably carried out at a temperature ranging from about 350°C to about 450°C. 9. The method as substantially herein described with reference to accompanying examples and drawings.

Full Text

FIELD OF THE INVENTION

The present invention relates to fuels.
Particularly, the present invention relates to alternative fuels.

BACKGROUND OF THE INVENTION & PRIOR ART

The recent energy crisis has created havoc in the world. The demand for fuel for industrial and domestic purposes, automobiles and the like is increasing at an alarming rate. With limited resources at hand, meeting the demand at an affordable price seems to be next to impossible. At this crucial juncture, the need for finding alternative fuel is of utmost importance.

Alternative fuels, also known as non-conventional fuels are substances that can be used as a fuel, other than conventional fuels. Conventional fuels include fossil fuels (petroleum (oil), coal, propane, and natural gas), and nuclear materials such as uranium.

Some well known alternative fuels include biodiesel, bioalcohol (methanol, ethanol, butanol), chemically stored electricity (batteries and fuel cells), hydrogen, non-fossil methane, non-fossil natural gas, vegetable oil and other biomass sources.

Waste rubber material is the most routine form of hydrocarbon-containing polymer materials. Used tyres of vehicles and, especially, metal-cord tyres are presently the principle source of waste rubber materials.

It is generally known that waste rubber materials can serve as a source of valuable recycled resources. However, the recovery of valuable resources is generally impeded by high strength of chemical bonds in macromolecules of vulcanized rubber. Several efforts have been made in the prior art to harness the energy trapped in such waste materials.
United States Patent 5,894,012 discloses a method and system for recovering marketable end products from waste rubber. The processing system pyrolyzes waste rubber to produce pyrolysis oil and carbon black and then purifies and refines these end products to broaden their commercial applications and to increase their market value.

United States Patent 5,976,484 discloses an intermittent continuous method for recovery of refined activated carbon from waste tires and the like and the device therefor. The method involves a series of heating, dry distillation and splitting decomposition.

United States Patent 6,743,746 discloses a catalyst for the low-temperature pyrolysis of hydrocarbon-containing polymer materials mainly intended for use in the recycling of rubber waste materials. The catalyst is prepared from a carbon-iron component in the form of microscopic carbon particles and ultra-dispersed iron particles. The catalyst further contains a metal-carbon component.

United States Patent 6,538,166 discloses a process and apparatus for treatment of Waste rubber. The process includes heating a quantity of rubber in an atmosphere at a negative pressure and at a temperature between 340 Celsius and 510 degrees Celsius such that the rubber is vaporized and defines a vaporized rubber. The vaporized rubber has a plurality of hydrocarbon constituents therein. A venturi separator sprays the vaporized rubber with oil having a boiling temperature greater than 175 degrees Celsius. The oil binds to heavy oil in the hydrocarbon constituents. A remaining portion of the vaporized rubber is condensed such that light oils in the hydrocarbon constituents liquefy and are separated from hydrocarbon gases.

United States Patent Application 20060265954 discloses a gasifier for the gasification of biomass and waste to produce combustible effluent, producing combustible gases for energy generation.

United States Patent Application 20050023124 discloses a pyrolytic conversion process of scrap tires to carbon products. A char containing less than 5% volatile matter is produced by pryolyzing shredded scrap vehicle tires and other rubber scrap material in an externally heated retort until the rubber is completely decomposed and until the temperature of the gases produced by the pyrolysis process reaches at least 500 degree C.

United States Patent 5,744,668 discloses a process of producing gasoline, diesel and carbon black with waste rubbers and/or waste plastics. The process comprises pyrolysis, purifying, catalytic cracking, and fractionation.

International Application No.: PCT/PL2004/000081 discloses a method and a device for continuous conversion of organic waste, in particular, highly contaminated waste plastics and worn out vehicle tyres.

The methods and the devices disclosed in the prior art are tedious, labour-intensive and time consuming. Further, the disclosed methods are not cost-effective. In addition, most of the known methods and means for rubber destruction are dangerous because of the environmental contamination with sulfur compounds, carcinogenic carbon black and certain other toxic substances. Thus, an efficient, safe and economic method of conversion of waste rubber and tyres into fuel is the need of the hour.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an alternative fuel.
It is another object of the present invention to provide an alternative fuel using waste rubber and used tyres as starting material.

It is yet another object of the present invention to provide a method for the conversion of waste rubber and tyres to fuel.

It is still another object of the present invention to provide a method which is simple and efficient for the conversion of waste rubber tyres to fuel.

It is still another object of the present invention to provide a method of conversion which is less time consuming.

It is still another object of the present invention to provide a method of conversion which is not labour-intensive.

It is still another object of the present invention to provide a method of conversion which is cost-effective.

It is still another object of the present invention to provide a solution for the mounting problem of disposal of waste rubber and used tyres.

STATEMENT OF THE INVENTION

Accordingly, the present invention relates to a method of conversion of waste rubber material to fuel, said method comprising the following steps:

i) heating the waste rubber material at a temperature ranging from about 300°C to about 500°C in the presence of a catalyst in a reactor to obtain gaseous products; ii) collecting said gaseous products; and

iii) cooling the collected gaseous products by passage through cooled pipelines maintained at 5-30°C and collecting condensed gaseous products.

Typically, the waste rubber material is waste tyre, shredded into pieces of about 20mm size.

Typically, said reactor is preferably a twin naked stainless steel cylindrical container having inner diameter of about 205 mm, outer diameter of about 210 mm and height of about 437 mm.

Typically, said catalyst is at least one catalyst selected from a group comprising aluminium silicate, barium silicate, beryllium silicate, calcium silicate, iron silicate, magnesium silicate, manganese silicate, potassium silicate, sodium silicate, zirconium silicate, copper silicate, tin silicate, iron silicate, lead silicate, tungsten silicate, cesium silicate lithium silicate, aluminium, bismuth, copper (cuprum), iron (ferrum), lead, magnesium, manganese, nickel, tin (stannum), tungsten, zinc, aluminium oxide, bismuth oxide, copper (cuprum) oxide, iron (ferrum) oxide, lead oxide, magnesium oxide, manganese oxide, nickel oxide, tin (stannum) oxide, tungsten oxide, zinc oxide, aluminium carbonate, calcium carbonate, sodium carbonate, bismuth carbonate, copper (cuprum) carbonate, iron (ferrum) carbonate, lead carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, tin (stannum) carbonate, tungsten carbonate, zinc carbonate, silicone carbide, calcium carbide, natural and synthetic zeolite, alumina, fuller's earth, bauxites, metal borates and metal borides.

Typically, said catalyst comprises about 10-80% silicate, about 0.001-50% zeolite, about 0.001-10% transition metal, about 0.001-40% metal oxide, about 0.001-10% metal borate, about 0.001-10% metal carbonate, about 0.001-50% fuller's earth, about 0.001-10% metal carbide, about 0.001-10% metal boride, about 0-10% activated charcoal, about 100% NiW loaded on amorphous silica-alumina, about 100% NiMo over gamma alumina, about 100% WC and Ni on carbon sheet, about 100% Ni octanate, about 100% cobalt on activated carbon, about 100% nano materials of alpha alumina 30-150 nm, about 100% gamma alumina 40-80 nm, and about 100% nano zinc 90-200 nm.

Typically, said catalyst has a particle size ranging from about 0.1 mm to about 10 mm.

Typically, said catalyst is introduced at a concentration ranging from about 0.001 to about 10% of the total mass of reactants in the reactor, preferably about 1 - 4%.

Typically, the heating of the waste rubber material is preferably carried out at a temperature ranging from about 350°C to about 450°C.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The invention will now be described with reference to the accompanying drawings in which:

Fig. 1 describes the pyrolysis reactor for large scale operation in accordance with this invention, generally indicated by the reference numeral 100.

The reactor is made of stainless steel with the capacity to convert about 10 Kg of waste rubber and used tyres. The reactor is cylindrical in shape with the inner diameter of 205 mm and outer diameter of 210 mm. The height of reactor is 437 mm and with the support the height is 586 mm. The height of the total reactor including magnetic stirrer and stand is 746 mm. Shredded rubber and catalyst are charged into a Distillation flask 37 with heating mantle 34. The Distillation flask 37 is sealed and sludge drain 15, washer thermocouple 36, catalyst baffle 33, insulation jacket 35, safety valve 18, stirring mechanism 31 and a fume outlet 29 connected to cold water condenser 26 running cold water from inlet 25 to outlet 27. The liquid condensed is collected in receiver vessel 23 placed in an ice bath and having drain valve 21, level indicator 22, pressure gauge 24 and is connected to vacuum pump 17 by silicon tubing 16 through a vacuum valve 20. The receiver vessel 23 is fitted with safety valve 18 through silicon tubing 16 to a secondary glass vessel of 2 litres for the collection of highly volatile gases.

After the addition of the waste material in the reactor, all valves are closed and air removed from the system with the help of a vacuum pump.

Fig. 2 illustrates the receiver vessel 23 in accordance with this invention which collects the condensed gaseous products.

Fig. 3 illustrates the distillation flask 37 in accordance with this invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method of conversion of waste rubber material to fuel, said method comprising the following steps:

i) heating the waste rubber material at a temperature ranging from about 300°C to about 500°C in the presence of a catalyst in a reactor to obtain gaseous products; ii) collecting said gaseous products; and

iii) cooling the collected gaseous products by passage through cooled pipelines maintained at 5-30°C and collecting condensed gaseous products.
In accordance with this invention, the waste rubber material is waste tyre, shredded into pieces of about 20mm size.

In accordance with the present invention, said reactor is preferably a twin naked stainless steel cylindrical container having inner diameter of about 205 mm, outer diameter of about 210 mm and height of about 437 mm.

In accordance with another embodiment of the present invention, said catalyst is at least one catalyst selected from a group comprising aluminium silicate, barium silicate, beryllium silicate, calcium silicate, iron silicate, magnesium silicate, manganese silicate, potassium silicate, sodium silicate, zirconium silicate, copper silicate, tin silicate, iron silicate, lead silicate, tungsten silicate, cesium silicate lithium silicate, aluminium, bismuth, copper (cuprum), iron (ferrum), lead, magnesium, manganese, nickel, tin (stannum), tungsten, zinc, aluminium oxide, bismuth oxide, copper (cuprum) oxide, iron (ferrum) oxide, lead oxide, magnesium oxide, manganese oxide, nickel oxide, tin (stannum) oxide, tungsten oxide, zinc oxide, aluminium carbonate, calcium carbonate, sodium carbonate, bismuth carbonate, copper (cuprum) carbonate, iron (ferrum) carbonate, lead carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, tin (stannum) carbonate, tungsten carbonate, zinc carbonate, silicone carbide, calcium carbide, natural and synthetic zeolite, alumina, fuller's earth, bauxites, metal borates and metal borides.

In accordance with another embodiment of the present invention, said catalyst comprises about 10-80% silicate, about 0.001-50% zeolite, about 0.001-10% transition metal, about 0.001-40% metal oxide, about 0.001-10% metal borate, about 0.001-10% metal carbonate, about 0.001-50% fuller's earth, about 0.001-10% metal carbide, about 0.001-10% metal boride, about 0-10% activated charcoal, about 100% NiW loaded on amorphous silica-alumina, about 100% NiMo over gamma alumina, about 100% WC and Ni on carbon sheet, about 100% Ni octanate, about 100% cobalt on activated carbon, about 100% nano materials of alpha alumina 30-150 nm, about 100% gamma alumina 40-80 nm, and about 100% nano zinc 90-200 nm.

In accordance with another embodiment of the present invention, said catalyst has a particle size ranging from about 0.1 mm to about 10 mm.

In accordance with another embodiment of the present invention, said catalyst is introduced at a concentration ranging from about 0.001 to about 10% of the total mass of reactants in the reactor, preferably about 1 - 4%.

In accordance with another embodiment of the present invention, heating of the waste rubber material is preferably carried out at a temperature ranging from about 350°C to about 450°C.

In accordance with another embodiment of the invention, air is removed from the reactor to create vacuum at the start of reaction.

Typically, a tyre comprises about 40% rubber, about 15% steel, about 5% textile fabrics, about 25% soot and about 15% chemical compounds.

The present invention provides an effective and highly efficient process for the conversion of waste rubber material into fuel.

Typically, the process is suitable for being carried out on a large scale. The special method, conducting the decomposition reactions catalytically in the presence of a novel and inexpensive catalyst provides a control over the temperature of the liquid fraction, and greatly improves the efficiency of the process and the quality of the final product.

The catalyst is introduced at a ratio ranging from about 0.01:1 to about 0.10:1 of the total mass of reactants in the reactor. As the quantity of catalyst is increased with the proportion of the total mass, the total reaction time is reduced and the yield is more.

As the temperature of the reaction is increased the yield percentage is more. Typically, 80% of the product is obtained at 390°C.

The decomposition product, in the form of gaseous and liquid mixture of smaller hydrocarbons is suitable to be recycled as raw material for polymers or liquid fuels or other chemical industry processes or serves directly as fuel for combustion engines, e.g. electric generators boilers, raw material for petroleum industry, bunker fuel and the like. The solid product obtained in the reactor is coke which can be used as fuel for thermal power plants and metallurgical industries.

As described in the figures 1-3, the present invention concerns also a device for conversion of waste rubber material into fuel, said device containing a housing (reactor), a heating system and a product collecting system. The charge of waste, say shredded tyre of about 20 mm size is introduced into the reactor having a hot bath whose temperature is maintained at about 300-500°C, preferably about 350-450°C. The catalysts are added at this stage to hasten the process of pyrolysis. The gaseous products of the decomposition are collected at the top and cooled by passing through pipes maintained at about 5-30°C. A reservoir maintained at 0°C stores the condensed product which is used as fuel.

During the reaction, the molecules of rubber pieces penetrate the structure of the catalyst and absorb on the active areas to react. A catalyst of this type has the advantage of presenting a large reactive surface and it also provides better reaction selectivity. A large pore catalyst is used for catalytic cracking which allows the largest molecules access to the active areas. The catalyst also serves to increase the rate of forward reaction and minimize the temperature of the reaction.

Typically, about 200 ml of heavy oil is added along with the catalyst.

A typical catalyst composition in accordance with this invention along with the respective optimum temperatures for the conversion of waste rubber material including used tyres into fuel is provided in Table 1.

A typical combination of the catalysts added at specific ratios to the waste rubber material and the yield of the fuel generally expected is tabulated in Table 2.

Table 2: Catalyst Ratio and the expected yield

Further, the novel construction of the housing as described in the present invention ensures right isolation and at the same time gives easy access to the interior of the device.

The novel construction of the heating system allows to fully utilize the heat energy and its supply to the whole volume of the reaction mixture. It provides a control over the temperature of the liquid fraction and prevents the reaction mass and impurities from entering into the cooling pipes which ensures long life of the bath.
The method and the device according to the present invention have been realized on industrial scale. According to the present invention, the process of catalytic conversion takes place continuously. The thermo-catalytic reactions in the reaction vessel do not require high pressure or addition of hydrogen. The catalyst is cheap and the spent catalyst can be recycled 1 to 2 times. Only one heating source is used in the technological production line. The product is of high quality and the by-product is potentially useful as wax for starting material for candle production.

The total time for the completion of reaction ranges from 1.5 to 3 hours, which is visibly indicated by stopping of liquids being collected in the receiver vessel.

Typically, the yield of the products obtained in accordance with this invention is as follows:

Liquid hydrocarbon: 40 - 60%; Solid coke: 40-50%; and Gas: 5 - 20%

The invention is further elaborated with the help of following examples; however, these examples should not be construed to limit the scope of the present invention.

EXAMPLE 1:

5 kg of waste rubber tyre was introduced into the reaction chamber of the device provided in accordance with this invention. To this, 0.09 kg of silicates and 0.01 kg of charcoal was added and the mixture was heated at 400°C. The gaseous products evaporating from the heated mixture were collected and passed through cooling pipes maintained at 15 °C. The condensed product was stored in the reservoir maintained at 0 °C. The yield obtained was as follows:

Liquid hydrocarbon - 50% Gas-10% Solid coke-40%.

EXAMPLE 2:

6kg of used car tyre shredded into pieces of about 20mm was introduced into the reaction chamber of the device provided in accordance with this invention. To this, 0.05 kg of silicates, 0.05 kg of zeolite and 0.05 kg of fuller's earth along with 200 ml of heavy oil was added and the mixture was heated at 410°C. The gaseous products evaporating from the heated mixture were collected and passed through cooling pipes maintained at 15 °C. The condensed product was stored in the reservoir maintained at 0 °C. The yield obtained was as follows:

Liquid hydrocarbon - 46 %
Gas-7%
Solid coke-47%.

EXAMPLE 3:

10 kg of waste rubber was introduced into the reaction chamber of the device provided in accordance with this invention. To this, 0.128kg of silicates, 0.032 kg of metal oxide, 0.032 kg of carbonate and 0.128 kg of fuller's earth along with 200 ml of heavy oil was added and the mixture was heated at 360°C. The gaseous products evaporating from the heated mixture were collected and passed through cooling pipes maintained at 15 °C. The condensed product was stored in the reservoir maintained at 0 °C. The yield obtained was as follows:

Liquid hydrocarbon - 53%
Gas-7%
Solid coke-40%.

EXAMPLE 4:

A typical liquid fuel i.e., petroleum product obtained in accordance with this invention on analysis gave the following results:
• Colour and Appearance: Light brown coloured oily liquid.
• Flash point (Abel's): 5 °C
• Sulphur content: 0.06%
• Pour point: Below minus 33 °C
• Distillation Range:

a) Initial boiling point: 85°C
b) 2% by volume distilled at 92 °C
c) 5% by volume distilled at 112 °C
d) 10 % by volume distilled at 130 °C
e) 20 % by volume distilled at 148 °C
f) 30% by volume distilled at 165 °C
g) 40% by volume distilled at 273 °C h) 50% by volume distilled at 290 °C i) 60% by volume distilled at 300 °C j) 70% by volume distilled at 310 °C k) 80% by volume distilled at 315 °C

• Kinematic viscosity at room temp. (30 °C): 7.69 est.
• Density at 15 °C: 0.81009 gms/ml
• Gross calorific value: 10765 cal/gm
19377 Btu/lb
• Custrip corrosion for 3 hrs. at 50 °C: Negative

TECHNICAL ADVANCEMENT

The instant invention offers several technical advancements and advantages as mentioned below:

• The method of conversion of waste rubber and used tyres to fuel disclosed in this invention is simple and effective.

• The disclosed method is less time consuming.

• Further, the method of conversion provided in the instant invention is not labour-intensive.

• The method provided in the instant invention is economic.

• The disclosed method provides an effective solution for the energy crisis encountered in the contemporary world.

• The disclosed method also provides an effective solution for the mounting problem of disposal of waste rubber and used tyres.

While considerable emphasis has been placed herein on the various components of the preferred embodiment, it will be appreciated that many alterations can be made and that many modifications can be made in the preferred embodiment without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

I Claim:

1. A method of conversion of waste rubber material to fuel, said method comprising the following steps:

i) heating the waste rubber material at a temperature ranging from about 300°C to about 500°C in the presence of a catalyst in a reactor to obtain gaseous products;

ii) collecting said gaseous products; and

iii) cooling the collected gaseous products by passage through cooled pipelines maintained at 5-30°C and collecting condensed gaseous products.
2. The method as claimed in claim 1, wherein the waste rubber material is waste tyre, shredded into pieces of about 20 mm size.

3. The method as claimed in claim 1, wherein said reactor is preferably a twin naked stainless steel cylindrical container having inner diameter of about 205 mm, outer diameter of about 210 mm and height of about 437 mm.

4. The method as claimed in claim 1, wherein said catalyst is at least one catalyst selected from a group comprising aluminium silicate, barium silicate, beryllium silicate, calcium silicate, iron silicate, magnesium silicate, manganese silicate, potassium silicate, sodium silicate, zirconium silicate, copper silicate, tin silicate, iron silicate, lead silicate, tungsten silicate, cesium silicate lithium silicate, aluminium, bismuth, copper (cuprum), iron (ferrum), lead, magnesium, manganese, nickel, tin (stannum), tungsten, zinc, aluminium oxide, bismuth oxide, copper (cuprum) oxide, iron (ferrum) oxide, lead oxide, magnesium oxide, manganese oxide, nickel oxide, tin (stannum) oxide, tungsten oxide, zinc oxide, aluminium carbonate, calcium carbonate, sodium carbonate, bismuth carbonate, copper (cuprum) carbonate, iron (ferrum) carbonate, lead carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, tin (stannum) carbonate, tungsten carbonate, zinc carbonate, silicone carbide, calcium carbide, natural and synthetic zeolite, alumina, fuller's earth, bauxites, metal borates and metal borides.

5. The method as claimed in claim 1, wherein said catalyst comprises about 10-80% silicate, about 0.001-50% zeolite, about 0.001-10% transition metal, about 0.001-40% metal oxide, about 0.001-10% metal borate, about 0.001-10% metal carbonate, about 0.001-50% fuller's earth, about 0.001-10% metal carbide, about 0.001-10% metal boride, about 0-10% activated charcoal, about 100% NiW loaded on amorphous silica-alumina, about 100% NiMo over gamma alumina, about 100% WC and Ni on carbon sheet, about 100% Ni octanate, about 100% cobalt on activated carbon, about 100% nano materials of alpha alumina 30-150 nm, about 100% gamma alumina 40-80 nm, and about 100% nano zinc 90-200 nm.

6. The method as claimed in claim 1, wherein said catalyst has a particle size ranging from about 0.1 mm to about 10 mm.

7. The method as claimed in claim 1, wherein said catalyst is introduced at a concentration ranging from about 0.001 to about 10% of the total mass of reactants in the reactor, preferably about 1 - 4%.

8. The method as claimed in claim 1, wherein the heating of the waste rubber material is preferably carried out at a temperature ranging from about 350°C to about 450°C.

9. The method as substantially herein described with reference to accompanying examples and drawings.

Documents:

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Patent Number

278033

Indian Patent Application Number

473/CHE/2008

PG Journal Number

52/2016

Publication Date

16-Dec-2016

Grant Date

08-Dec-2016

Date of Filing

26-Feb-2008

Name of Patentee

DR. DHESINGH SIVARAJ

Applicant Address

5/407, HONNI ILLAM KANNADASAN STREET MOGAPPAIR (WEST) CHENNAI 600 037

Inventors:

#	Inventor's Name	Inventor's Address
1	DR. DHESINGH SIVARAJ	5/407, HONNI ILLAM KANNADASAN STREET MOGAPPAIR (WEST) CHENNAI 600 037

PCT International Classification Number

C10B

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA