System and method for tire conversion into carbon black, liquid and gaseous products
09663662 ยท 2017-05-30
Assignee
Inventors
- Vitaly B Khusidman (Warren, NJ, US)
- Vasily Jorjadze (Shoreham, NY, US)
- Tamaz Marsagishvili (Tbilisi, GE)
- Akaki Peikrishvili (Tbilisi, GE)
- Grigor Tatishvili (Tbilisi, GE)
Cpc classification
C09C1/482
CHEMISTRY; METALLURGY
C01B3/02
CHEMISTRY; METALLURGY
Y02E60/36
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
C10B53/07
CHEMISTRY; METALLURGY
Y02P20/143
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
C10B53/07
CHEMISTRY; METALLURGY
C01B3/02
CHEMISTRY; METALLURGY
Abstract
A reactor for converting scrap tire material into output products, while allowing controlling the characteristics of the products within certain ranges, includes a pre-processing zone maintained at a first average temperature, at least one primary processing zone maintained at a second average temperature, at least one secondary processing zone maintained at a third average temperature, a post-processing zone that cools scrap tire material to a fourth temperature, at least one water injector that introduces water into the interior of the secondary processing zones, and potentially also the primary zone, and a transport mechanism that moves, and may mix, scrap tire material across the pre-processing zone, primary processing zone, secondary processing zone, and post-processing zone.
Claims
1. A method for converting scrap tire material into carbon black and other materials, the method comprising: heating scrap tire material to a first temperature in a pre-processing zone of a reactor; heating the scrap tire material to a second temperature in a primary processing zone of the reactor; heating the scrap tire material to a third temperature of at least 700 degrees Celsius in a secondary processing zone of the reactor; introducing water to the secondary processing zone of the reactor while maintaining the scrap tire material at the third temperature; and cooling down the solid remains to the fourth temperature in a post-processing zone of the reactor.
2. The method of claim 1 wherein the first temperature is between 300 and 700 degrees Celsius.
3. The method of claim 1, wherein the second temperature is between 700 degrees Celsius and 890 degrees Celsius.
4. The method of claim 1, wherein the third temperature is between 700 and 890 degrees Celsius.
5. The method of claim 1, wherein the third temperature is 900 degrees Celsius or higher.
6. The method of claim 1, wherein the scrap tire material is introduced to the secondary processing zone at a first rate of mass per second, and further comprising varying the rate in mass per second of the introduction of water to control quality of produced materials.
7. The method of claim 1 further comprising introducing water to the primary processing zone.
8. The method of claim 1 further comprising maintaining near normal atmospheric pressure within the reactor.
9. The method of claim 1 further comprising continuously mixing the scrap tire material throughout the primary processing zone.
10. The method of claim 1 further comprising continuously mixing the scrap tire material throughout the secondary processing zone.
11. The method of claim 1 further comprising advancing the scrap tire material through each of the pre-processing zone, the primary processing zone, the secondary processing zone, and the post-processing zone.
12. The method of claim 11, wherein advancing the scrap tire material further comprises advancing the scrap tire material at a different speed in each of the four zones.
13. The method of claim 11, wherein advancing the scrap tire material further comprises advancing the scrap tire material at the same speed in at least two of the four zones.
14. The method of claim 1 further comprising removing ash from carbon black converted from the scrap tire material.
15. The method of claim 1 further comprising removing metal from carbon black converted from the scrap tire material.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The preceding summary, as well as the following detailed description of the disclosed device and method, will be better understood when read in conjunction with the attached drawings. It should be understood that the invention is not limited to the precise arrangements and instrumentalities shown.
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DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
(15) Embodiments of the disclosed apparatus and method relate to the production of carbon black, oil, gas, and metal through the thermal treatment of used (scrap) tires or other rubber materials; embodiments of the disclosed reactor and method enable finer control over the quality and ranges of materials produced during conversion. Some embodiments achieve this through conversion that includes conversion of organic material at elevated temperatures in presence of water steam; this may create new molecules combining products from the scrap tire material with hydrogen and oxygen sourced from the water. The use of a sequence of temperature stages with the strategic introduction of water steam enhances all existing processes for conversion of scrap tires into carbon black. Water treatment makes it possible to control quality characteristics of the produced material for different industrial applications.
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(17) Some embodiments of the disclosed apparatus and method involve conversion and extraction of resources from tire scrap material. Conversion is a generic term used hereafter to denote a variety of chemical processes including but not limited to scrap tire thermolysis, as set forth in further detail below. In one embodiment, tire scrap material is the material obtained from discarded or spent tires; tires may be annular components that cover and protect the wheels of vehicles such as automobiles, trucks, motorcycles, tractors, bicycles, and similar devices. The tire scrap material may contain any material or combination of materials used to construct tires. The tire scrap material may include one or more elastomeric polymers, which may be combined into copolymers. The elastomeric polymers may include synthetic or natural rubber material. The elastomeric polymers may include butadiene. The elastomeric polymers may include styrene. In addition to natural or synthetic rubber, the scrap tire material may include carbon black, which may be fine paracrystalline carbon material used for pigmentation and reinforcement of tires; the total content of carbon in the tire material may vary between 67% and 76% of the scrap tire material, depending on such factors as whether the tires were used for passenger or freight conveyance, whether they were intended for on or off-road use, and whether they were intended for summer or winter weather. The tire scrap material may include metal, such as steel used for reinforcement of tires such as steel-belted radials. The tire scrap material may include natural or synthetic textile material used to reinforce tires, such as silk, cotton, nylon, or para-aramid fibers. The tire scrap material may include sulfur, such as sulfur added for vulcanization. The tire scrap materials may include other additives such as zinc oxide and clay. For the sake of clarity, tire scrap material that is in the process of having materials extracted from it is referred to as scrap tire material, even though after passing through one or more stages of the process as disclosed below, some products may have been extracted from the scrap tire material, modifying its chemical or physical composition
(18) Some embodiments of the disclosed apparatus and method involve extracting products from scrap tire material using chemical conversion. In some embodiments, conversion is a process whereby a substance, such as scrap tire material, is broken down into simpler components using heat. Some embodiments of the disclosed apparatus and method involve extracting products from scrap tire material using thermolysis. In some embodiments, thermolysis involves heating of scrap tires or other rubber-containing material in presence of water steam, converting them into simpler and smaller organic compounds. In some embodiments of the disclosed method, a portion of the material produced is in excess of the original mass of the scrap tire material, which is accomplished by adding hydrogen and oxygen released from water molecules from the water introduced into the reactor by the water injectors 7; the use of some embodiments of the disclosed process thus unexpectedly produced a higher yield of useful materials than was possible according to previous methods. This process may be accompanied by production of carbon black, gas and oil. Industrial processes are usually implemented in continuous mode, in which new material constantly arrives at the reactor and solid products and any residue are continuously removed. Products produced as a result of conversion may include carbon black, gases, and oils; the gases and oils may have properties conducive to their use as fuel.
(19) In some embodiments, the disclosed process and apparatus extract carbon black from the tire scrap material for commercial use. Carbon black may be classified according several characteristics, as defined by the American Society for Testing and Materials (ASTM) of West Conshohoken, Pa., of which three main characteristics may be of special importance: particle size, structure size and surface. Combination of these characteristics may mostly determine the value of the carbon black and its applicability to various industries. Embodiments of the disclosed method and apparatus have the advantageous ability to control those characteristics in the extracted carbon black. In some embodiments, the control of the carbon black characteristics is accomplished by measured addition of water and maintaining certain temperatures at certain stages of the material conversion, as described in further detail below.
(20) The reactor 100 may be made of any material suitable for use in the method 600 described below. Material used to make the reactor 100 may include high temperature resistant steel. Material used to make the reactor 100 may include ceramic material. Material used to make the reactor 100 may include additional materials such as quartz or silica. The reactor 100 may include one or more tubular sections, in which the scrap tire material is placed and heated. The heating may be accomplished using any process suitable for achieving the first, second, and third temperatures. For instance, the heating may be accomplished using gas or liquid fuel jets 16; in some embodiments, the jets 16 are arranged in an arcuate array around a portion of the tube, as shown in
(21) The reactor 100 includes a transport mechanism 12 that moves scrap tire material from the pre-processing zone to the primary processing zone, from the primary processing zone to the secondary processing zone and from the secondary processing zone to the post-processing zone. In some embodiments, the transport mechanism 12 further includes a screw conveyor 13. In one embodiment, a screw conveyor 13 is a device having at least one screw 12a that rotates in place, with one or more threads 17, also known as helical blades, whose rotation causes the scrap tire material to move in a direction 18 axial to the rotation of the at least one screw.
(22) The screw conveyor may cause the scrap tire material to advance at different rates in different portions of the conveyor. In some embodiments, where the screw conveyor includes multiple screws, a first screw may turn at a first rate, while a second screw turns at a second rate that differs from the first rate; as a result, the first screw may move scrap tire material more rapidly or less rapidly than the second screw, for a given lead or pitch. In some embodiments, the rotation speed of at least one screw is regulated to vary the speed of advancement of scrap tire materials. In one embodiment, the reactor 100 includes one or more manual controls permitting a user to vary the speed of rotation of one or more screws; for instance, the user may observe sensor outputs or other information indicating how the conversion process is progressing, and may speed up or slow down one or more conveyor screws to ensure that the process is performed more slowly (e.g. to ensure a more complete conversion) or more rapidly (e.g., to increase throughput where the rate of conversion is higher than the rate of movement of material through the reactor). In other embodiments, a processor (not shown) such as a microprocessor, computer, or other analog, digital, or mechanical automated control system changes the rate of rotation of one or more screws in response to one or more detected changes in the progress of conversion.
(23) In other embodiments, the screw conveyor has a variable lead. In one embodiment, the lead is the amount of axial displacement caused by as single rotation of the screw. The lead may be varied by varying the pitch, as illustrated in
(24) In some embodiments, the transport mechanism 12 includes integrated sections, each featuring both material advancing and mixing blades. For instance, the screw conveyor may further include one or more mixing blades. In some embodiments, the screw conveyor includes a plurality of mixing blades 30a-l affixed to the screw conveyor; the mixing blades 30a-l may rotate with the same angular velocity as the screw 12a to which the mixing blades are fixed. In some embodiments, the mixing blades 30a-l are positioned between the threads of the screw 12a. For the purposes herein, a mixing blade 30a-l is positioned between two adjacent threads if the mixing blade 30a-l is positioned in a valley between two adjacent crests, traveling in the axial direction, of the threads 17 of the screw, as illustrated in
(25) There may be less than one blade 30a-l per step of the threads, where a step is passage from one trough between a first thread peak and a second thread peak to a trough on the other side of one of the second thread peak in the axial direction. There may be one or more blades 30a-l per step of the threads; for instance, as shown in
(26) The mixing blades 30a-l may have any shape conducive to stirring up scrap tire material. For instance, the faces of the mixing blades 30a-l may have any curved or polygonal perimeter, or any combination of curved or polygonal forms. The blades 30a-l may have one or more projections such as fingers or teeth. The blades 30a-l may have one or more indentations. There may be one or more holes through the blades 30a-l. The faces may be oriented orthogonally to the axis of the screw 12a, parallel to the axis of the screw, or at any other angle with respect to the axis of the screw. The blades 30a-f may be substantially straight; the blades 30a-f may be twisted. The blades 30a-f may present convex or concave surfaces.
(27) The blades 30a-l may be positioned at any angle relative to lines drawn from the axis of the screw 12a and intersecting the blades 30a-l. For instance, where the faces of the blades 30a-l are substantially planar, the faces of the blades 30a-l may be parallel to lines drawn radially from the axis of the screw 12a and intersecting the blades, as shown in
(28) Pairs of the blades 30a-l may be positioned opposite each other across the axis of rotation of the screw 12a. For instance, where the blades are positioned orthogonally to the axis, a first blade 30a may project orthogonally to the axis of the rotation of the screw 12a in a first direction, and a second blade 30b may project orthogonally to the axis of the rotation of the screw 12a in a second direction approximately 180 degrees ( radians) about the axis of rotation from the first direction; in some embodiments, the first blade is orthogonal to the same point on the axis as the second blade, while in other embodiments, the first blade is orthogonal to a different point on the axis from the second blade.
(29) In some embodiments, as shown in
(30) In some embodiments, configuration of the mixing blades 30a-l varies over the length of one screw 12a; for instance, the angle, frequency of blades per rotation, surface area, shape, and space between blades and the shaft or threads may vary over the length of the screw 12a. As a further example, in one embodiment, the screw conveyor has a constant lead and mixing blades 30a-l. Another embodiment combines integrated mixing blades 30a-l with a variable lead. Likewise, the configuration of blades may vary from one screw to another. The configuration of blades may vary from one zone to another of the reactor 100; for example, the mixing blades 30a-l may be present on all screws in the primary 2 and secondary 3 processing zones, and absent from all screws in the pre-processing zone 1 and post-processing zone 4.
(31) The rotation of the blades may stir the scrap tire material while the threads cause the tire material to advance axially along the screw conveyor. In some embodiments, mechanical agitation of the scrap tire material and variations in the rate of movement along the screw conveyor of the scrap tire material enables greater control over the quality and range of products extracted during conversion. In some embodiments, this improves the quality and completeness of material mixing, which in turn enables equal heating of the entire mass of the scrap tire material moved through the reactor despite low thermal conductivity of the material; this in turn may guarantee the quality of the output products.
(32) In other embodiments, as shown in
(33) The reactor 100 may include at least one tube, the at least one tube containing the pre-processing zone, the at least one primary processing zone, the at least one secondary processing zone, and the post-processing zone. The at least one tube may be one tube; for instance, in some embodiments, the reactor 100 includes a single tube divided into at least the pre-processing zone 1, the at least one primary processing zone 2, the at least one secondary processing zone 3 and the post-processing zone 4. In other embodiments, the at least one tube is a plurality of tubes. For example, as illustrated in
(34) In some embodiments, as illustrated in
(35) The at least one tube may include a plurality of tubes arranged in series. For instance, as shown in
(36) In other embodiments, the at least one tube further comprises a plurality of tubes arranged in parallel. In other words, in some embodiments, as shown in
(37) The pre-processing zone 1 is maintained at a first temperature, as described in further detail below. In some embodiments, the first temperature is between 300 degrees Celsius and 700 degrees Celsius. The scrap tire material may gradually heat up to the first temperature as the scrap tire material moves through the pre-processing zone 1. The primary processing zone 2 is maintained at a second temperature; the second temperature may be between 700 degrees Celsius and 890 degrees Celsius. The scrap tire material may gradually heat up as it moves through the primary processing zone 2.
(38) The reactor 100 includes a secondary processing zone 3 maintained at a third temperature. The third temperature may be between 700 degrees Celsius and 890 degrees Celsius, or the third temperature may be 900 degrees Celsius or higher, depending on the desired outcome, as described in further detail below. The reactor 100 includes a water injector system 7 that introduces water into the interior of the secondary processing zone 3. The water injector system 7 may introduce water in the form of liquid, vapor, or a combination of water vapor and liquid water. The water injector system 7 may include one or more nozzles (not shown) that inject the water into the respective zones. The one or more nozzles may be connected via tubes to a water steam generator 8 heated by the gas produced by the conversion process. The water steam generator 8 may be a boiler; in some embodiments, the water steam generator 8 is heated using gases extracted during the process 600 described below. The water may be added as described below at various stages of the process. For instance, in some embodiments, the water injector system 7 also adds water to the primary processing zone 2. In some embodiments, introducing the water into the secondary or primary zones enhances control over the quality and quantity of extracted products.
(39) The reactor 100 includes a post-processing zone 4 maintained at a fourth temperature. The fourth temperature may be between 80 degrees Celsius and 300 degrees Celsius. The temperature may drop further during the extraction of materials as described in further detail below. In some embodiments, as shown in
(40) The reactor 100 may include one or more components for collecting products extracted from the scrap tire material. The solid products may be extracted from the cooling down post-processing zone 4. There may be a tube 6 that permits solid materials to exit the cooling down zone 4 under the influence of gravity. The tube 6 may have a funnel-like portion. The tube 6 may have an airlock; the airlock may maintain the low-oxygen atmosphere within the reactor 100. As shown in
(41) In some embodiments, the reactor 100 also includes one or more components that process the scrap tire material prior to entry in the reactor 100. A shredder 31 may break the scrap tire down into small pieces, increasing the surface area of the scrap tire material for more efficient conversion process. In some embodiments, a metal separator 33 removes reinforcing metals from the scrap tire material prior to the entry of the scrap tire material into the reactor; the metal may be stored in a metal receiver 34. The reactor 100 may include a component (not shown) for extracting textile material; for instance, the reactor 100 may include a fluff-removal machine (not shown). The scrap tire may enter the reactor 100 through a loading hopper 5; the hopper 5 may include an airlock, which may maintain the low-oxygen environment within the reactor 100.
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(43) Reviewing
(44) In some embodiments, metal material, such as reinforcing steel, is removed from the scrap tire material before the insertion of the scrap tire material into the pre-processing zone 1. This may be performed by the metal reinforcement extractor 33 and metal reinforcement receiver 34 of
(45) In some embodiments, the first temperature is between 300 degrees Celsius and 450 degrees Celsius. The scrap tire material may reach this temperature by gradually heating up as it passes through the pre-processing zone. In some embodiments, the scrap tire material reaches the first temperature at approximately the midpoint of its trip through the pre-processing zone 1, of
(46) The method 600 includes heating the scrap tire material to a second temperature in a primary processing zone of the reactor (602). The second temperature may be between 700 degrees Celsius and 890 degrees Celsius. The scrap tire material may gradually heat up to the second temperature as it passes through the primary processing zone 2. In some embodiments, where the beginning of the primary processing zone 2, of
(47) In some embodiments, water is introduced into the primary processing zone 2. The water may be introduced in the form of liquid water. The water may be introduced in the form of water vapor. The water may be introduced in the form of a combination of water vapor and liquid water.
(48) The method 600 includes heating the scrap tire material to a third temperature in a secondary processing zone of the reactor (603). In some embodiments, the third temperature is between 700 degrees Celsius and 890 degrees Celsius; at this temperature, carbon back may be produced from the tire scrap material. The carbon black may also be refined at this temperature. In some embodiments, ash is produced at this stage; the ash may be removed as described below. The ash may be produced from silicone additives or other materials incorporated in the scrap tire material.
(49) In some embodiments, the addition of water produces carbon black with high porosity. For instance, the porosity of the carbon black may be such that the difference between the nitrogen surface area (N2SA) and the statistical thickness surface area (STSA) is between 90 m.sup.2/g and 250 m.sup.2/g.
(50) In a further embodiment, the third temperature is 900 degrees Celsius or higher; at this temperature the carbon black may be converted into volatile material, including gases. The volatile materials may include flammable gases. The gases may include hydrogen gas (H2). The gases may include carbon monoxide (CO). The gases may include carbon dioxide (CO2). The gases may include methane (CH4). The gases may include ethane (C2H6). The gases may include propane (C3H8). The gases may also include small quantities of other gases.
(51) The method includes introducing water into the secondary processing zone of the reactor (604). The water may be introduced as liquid, vapor, or a combination of water vapor and liquid water. In some embodiments, introduction of water in a temperature range of 700 degrees Celsius to 890 degrees Celsius ensures that the carbon black produced in that process will be of superior quality; the water may assist in producing higher quality carbon black by functioning as a chemical reagent. Water mass may be introduced in the range between 0% and 150% of the material mass per second, with the temperature at a level between 700 C and 890 C at certain stages of the material conversion. Lower water quantities and lower temperatures may contribute to production of carbon black material approximating N7XX or N6XX ASTM grades. Higher water quantities and higher temperatures may contribute to production of carbon black material approximating N2XX or N1XX ASTM grades.
(52) Where the third temperature is above 700 degrees Celsius, the introduction of water steam may cause hydrogen and oxygen from the water to combine with carbon from the scrap tire material to form a greater quantity of fuel gas, according to the following formula: CnHm (solid)+H2O (gas).fwdarw.H2 (gas)+CO (gas)+CO2 (gas)+CnHm (liquid)+CH4 (gas)+C2H2 (gas)+C2H6 (gas)+C3H8 (gas)+C4H10 (gas). In some embodiments, the introduction of the right amount of water into the secondary processing zone 3, of
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(54) The method 600 includes cooling down the remaining material to a fourth temperature in a post-processing zone of the reactor (605). The fourth temperature may be between 80 degrees Celsius and 300 degrees Celsius. The temperature may drop further during the extraction of materials as described in further detail below.
(55) Some embodiments of the method involve mechanically agitating the scrap tire material. The one or more material mixing blades 4, for instance as shown in
(56) The atmosphere within the reactor 100 may be substantially isolated from the outside air. In some embodiments, the method includes maintaining an environment substantially free of gaseous oxygen within the reactor. The substantially oxygen-free atmosphere may be maintained using airlocks in the input hopper 5 and in the output tube 6 as shown in
(57) Some embodiments involve removing metal from the scrap tire material in the post-processing zone 4 of
(58) The process may involve converting the scrap tire material into volatile liquid and gaseous matters as well as solid matter. In some embodiments, the method 600 involves separating out gaseous material released by the scrap tire material. This may be accomplished using the gas pump 28 of
(59) In some embodiments, the extracted gases are used as fuel to heat the reactor 100; for instance, the extracted hydrogen gas, methane, or other flammable gases may be fed into the gas jets 16 as fuel gas 15, as shown in
(60) It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.