Patent Application
20180237322
Apparatus to convert organic waste into syngas while manufacturing glass products and method thereof.
This application claims priority from the following U.S. provisional patent applications: Ser. No. 62/462,551 filed on Feb. 23, 2017; Ser. No. 62/490,455 filed on April 26, 2017; and Ser. No. 62/579,051 filed on Oct. 30, 2017. The disclosures of the prior applications are considered to be part of the disclosure of the accompanying application and are hereby incorporated by reference.
This invention relates to a novel glass furnace and associated process that disassociate through gasification the chemical constituents in organic waste that is charged into the glass furnace into syngas by using the radiant heat of the melted glass within the furnace with little to no contamination of the glass melt that may then be used to produce any number of glass products such as fiber glass, glass beads, and ceramic-glass beads.
Many industrial processes require the use of high temperature furnaces. For instance, certain products sourced from glass or steel, are produced by heating the source material to temperatures sufficiently high enough to melt the material which is then transported in its liquid state to production equipment and processes which then create a commercially useful product from the melt. Traditionally, the heating step has been carried out by introducing the source material into a specially designed furnace and directly heating the source material in the furnace by combusting a fuel, using electricity, or both but not at the same time. The process of heating the material consumes a tremendous amount of energy and there have been many proposed means of capturing the heat to reuse it for another purpose. One proposed purpose is for gasification of organic waste into its chemical constituents.
The effective management and utilization of waste is a global issue. Current waste management techniques, as suggested by regulatory agencies, such as the U.S. Environmental Protection Agency (EPA), include source reduction first, recycling and composting second, and, finally, disposal in landfills or waste combustors. Other techniques of managing waste include converting the waste to energy involving processes such as incineration and pyrolysis. There are many types of waste including municipal solid waste, commercial and industrial waste, construction and demolition waste, electronic waste, medical waste, nuclear waste, and hazardous waste. Municipal solid waste (MSW), also called urban solid waste, trash, rubbish, or garbage, mainly comprises household/domestic waste. MSW is generally in solid/semi-solid form and includes both organic and inorganic materials such as paper, cardboard, plastic, textiles, glass, metals, biodegradable waste (e.g., food waste, yard sweepings/trimmings, wood waste), inert waste (e.g., dirt, rocks) and may include small quantities of miscellaneous materials such as batteries, light bulbs, medicines, chemicals, fertilizers, among other materials. Typically, MSW is found to be predominantly paper, cardboard, wood, yard waste, and food waste, although exact compositions can vary from one region to another (e.g., depending upon the levels of recycling carried out in that region). Without the effective management of waste, available landfill space within the United States will diminish. Other problems associated with landfills include the production of greenhouse gases, groundwater pollution, adverse impact on local biodiversity, and more.
A form of waste management includes gasification. Gasification is a process for the conversion of a carbonaceous feedstock such as coal, petroleum, biofuel, biomass, organic waste, and other wastes by exposure to high temperature and the addition of oxygen into a combustible gas such as synthesis gas. Synthesis gas, commonly referred to as syngas, is a mixture of varying amounts of carbon dioxide, carbon monoxide and hydrogen (CO2+CO+H2) and has a variety of applications. The syngas can be used to generate power by combusting it directly in a gas turbine, boiler or reciprocating engine, by feeding it into a fuel cell, and/or waste heat can be used in the generation of steam which can provide additional power through a steam turbine. Syngas can also be used for the production of hydrogen or liquid fuels or chemicals, gaseous fuels, synthetic natural gas, and/or carbon monoxide, some of which may be used as raw materials in the manufacture of other chemicals such as plastics. Gasification is thus a process for producing value-added products and/or energy from carbonaceous materials.
The high temperatures required to operate many furnaces are ideal for the gasification of organic wastes. It would be very desirable to operate a glass furnace to produce any number of glass products while at the same time taking advantage of the high temperatures within the furnace to gasify organic waste and produce syngas. There are a number of benefits such as making more effective use of an industrial furnace, leveraging the heat required to melt the glass to also gasify the organic waste, reducing the amount of waste that would otherwise be deposited into a landfill, and of course the creation of syngas which may be sold or combusted on site or used for other processes. It has been the object of individuals to create a furnace that would not only melt glass but also gasify organic waste.
An example of one such proposed means is U.S. Pat. No. 9,163,187 issued to Galley et al. on Oct. 20, 2015 titled “Gasification of combustible organic materials”. Here Galley discloses a first furnace melting glass that is part of a larger system that also comprises a boiler and a second furnace and a process for converting combustible organic waste materials into “synthesis gas” more commonly known as “syngas”. In Galley's disclosure the organic waste material is mixed with the glass melt of the first glass furnace and via pyrolysis of the organic waste material along with the introduction of steam or air syngas is produced. The syngas is then transported to the second furnace and is used to assist other combustion processes already present in the second furnace to melt the contents therein so as to create commercial products. The heat created by the second furnace is then transported to a boiler where steam is created via a heat exchange process. The steam created by the boiler is then transported to the first glass furnace and the process repeats. The glass in the first furnace, having been contaminated by the organic waste material that remains, contains undesirable oxides and heavy metals that are rendered inert (neutralized) in a glassy mass. This glassy mass is discharged from the first furnace and granulated for disposal or used as granules in civil engineering applications. Examples include use as a filler for bitumen or asphalt type materials for roads, pavements or other construction materials. While the Galley disclosure reduces the amount of waste that would normally be assigned to a landfill by converting much of it into syngas or as a filler material it is a rather complex industrial system where the first glass furnace, boiler, and second furnace along with any interconnecting schemes must be built in close proximity. The cost of implementing such a system and the associated land requirements makes the Galley disclosure difficult to implement. In addition, the glass melt in the first glass furnace is contaminated by the organic waste and is thus limited as to the range of possible glass products that may be manufactured from it.
US patent application publication 2017/0336070 by Inskip discloses a furnace and method thereby wherein waste heat from the furnace is used to promote a depolymerization process in waste plastics that creates a combustible fuel. A loop is thereby created, in which waste heat from the furnace drives the thermal depolymerisation process, and fuel produced by thermal depolymerisation is fed back into and consumed by the furnace. An advantage with the Inskip disclosure is that the melt within the furnace is never in contact with the waste plastic and thus is not contaminated by the waste plastic and is suitable for all of its intended commercial uses. However the depolymerization process as to plastics is a relatively low temperature process and not conducive to high temperature processes wherein glass products are made.
Known systems do not provide for a glass furnace that simultaneously melts a glass charge while also gasifying organic waste into syngas without contaminating the glass melt and thereby limiting the range of possible glass products that may be manufactured.
It is an object of the invention to provide for a glass furnace and process that allows for the gasification of waste organic material into syngas and for the melting of glass for use in a variety of commercial uses simultaneously within the furnace.
It is another object of the invention to refine the syngas within the associated channel of the furnace to remove the tar and other contaminants thus improving the purity of the syngas for its intended purpose.
The body of the furnace will generally be cylindrical in geometry with a vertical orientation and may be divided into two portions: a lower and an upper portion. The lower portion will be occupied by melted glass batch materials that may be used in the production of any number of glass products. The upper portion is a void space.
In the lower portion of the body an arrangement of burners using an air/gas mixture as fuel may be found followed by an arrangement of electrodes. The burners and electrodes are for the heating of the glass batch material within the lower portion of the body. Also within the lower portion of the body is a glass batch material pressure feeder, an opening to remove slag, and a bubbler ring to inject one or more of oxygen, air, or steam into the glass melt.
In the upper portion there are two ports, a first port for the introduction of glass batch material to augment the glass batch material pressure feeder found in the lower portion of the body and a second port for the introduction of organic waste into the body. The second port is found at the apex of the furnace body. Finally, an upper bubbler ring for the injection of one or more of oxygen, air, or steam into the upper portion of the body may be found.
At the division of the lower and upper portions will be found a port to draw off the melted glass batch material. The port leads into a channel that transports the melted glass batch material to the forehearth where the melted glass batch material is then presented to glass production equipment to manufacture glass fiber insulation, glass beads, and ceramic-glass beads. The channel is further divided into multiple zones with each zone containing independently controlled electrodes to maintain the temperature of the melted glass batch material at a proper level within that zone. The channel also allows for the passage and refinement of the syngas produced when the organic waste is gasified.
The method of producing the syngas begins with charging the lower portion of the body with glass batch material to a proper level. Once the body has been so charged the burners will be activated to begin the heating process and will continue to heat the glass batch material until the glass batch material is sufficiently melted to a viscosity of log four to log five to allow for the proper operation of the electrodes. At this point the burners are deactivated and the electrodes are activated. It is important that the burners are not active when the organic waste is gasifying as the gases created by the burners disrupt the ambient air flow in the upper portion of the furnace body. It is essential that there are no disruptions to the ambient air flow in the upper portion of the furnace body when the organic waste is introduced above the surface of the melted glass batch material. Once the electrodes have heated the glass batch material to the required temperature the organic waste may be charged into the upper portion. As the organic waste falls into the furnace body it will be exposed to increasingly greater temperatures. One or more of oxygen, air, or steam supplied by the lower and upper bubbler rings will react with the organic waste at a set temperature, and the organic waste will gasify into syngas. The syngas is drawn into the channel where it passes above the melted glass batch material flowing in the channel. As the syngas travels between the zones in the channel, tar and other impurities are removed by the continued exposure to the high temperatures of the melted glass batch material traveling below the syngas. At the end of the channel the syngas is drawn off to be processed into other gases. The melted glass batch material is fed into glass manufacturing equipment to manufacture either glass fiber insulation, glass beads, or ceramic-glass beads. Any organic waste that is not gasified drops into the melted glass batch material and reacts with the oxygen or steam being injected by the lower bubbler ring for a second attempt to gasify the organic waste into syngas. Failing the second attempt, the residual material from the organic waste, which may be ash, precipitates to the bottom of the furnace body having been rendered inert (neutralized) in a glassy mass to be removed as slag, granulated for use in civil engineering applications as a filler for bitumen or asphalt type materials for roads, pavements, or for other potential uses.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
Neither this summary nor the following detailed description defines or limits the invention. The invention is defined by the claims.
The present invention will become more fully understood from the detailed description and accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
At the base of body 12 are shown three submerged burners 22 combusting natural gas with one or more of hydrogen, oxygen, or air. Submerged burners enhance heat transfer by mixing the fuels and oxidant produced by submerged burners 22 directly into and under the surface of glass batch material 18 being melted. Placing submerged burners 22 in the base of body 12 results in improved heat transfer and vigorous convective stirring of the melt. The three submerged burners 22 are shown as an example and the actual count may vary depending upon the size of body 12.
Depending upon the size of body 12 side burners 24 may be employed to assist submerged burners 22 in melting glass batch material 18 within lower portion 14. Similar to submerged burners 22, side burners 24 also combust natural gas with one or more of hydrogen, oxygen, or air and the actual count varies depending upon the size of body 12. However once glass batch material 18 melts and achieves a certain viscosity, submerged burners 22 and side burners 24 are to be turned off and electrodes 26 are to be turned on.
Glass batch material 18 conducts electricity once it has melted and electrodes 26 may heat glass batch material directly by passing an electrical current through the molten glass batch material 18. Electrodes 26 are commonly made from molybdenum as molybdenum is less affected by oxidation at the high temperatures found in glass melting furnaces and provides a reasonably long and reliable life. Electrode lifespan may be further increased by coating the electrodes with a zirconium based oxide. It is important to turn off submerged burners 22 and side burners 24 because of their vigorous convective stirring of melted glass batch material 18 is disruptive to the ambient air in upper portion 16, and their use adversely impacts the reliability and life of electrodes 26. It is important, for the purposes of this disclosure, that the ambient air in upper portion 16 is left undisturbed to the extent possible.
About the perimeter of body 12 and below glass surface line 20 is lower bubbler ring 32. Lower bubbler ring 32 is a tube encircling the perimeter of body 12 with one or more nozzles projecting through body 12 and into glass batch material 18. By feeding one or more of hydrogen, oxygen, air, or steam into the tube the same may be fed into melted glass batch material 18. Introducing one or more of hydrogen, oxygen, air, or steam into the organic waste is part of the gasification process of the organic waste.
At the base of body 12 is lower glass batch material feeder 28 that is used to feed glass batch material 18 into body 12 to replace glass batch material 18 that is withdrawn along channel 46 and passed out through glass melt feeder 60 and into glass production equipment 62. Also at the base of body 12 is slag receiver 30 that is used to draw off organic waste that has not gasified. Slag recovered from body 12 may be diverted to a storage and processing area where it may be granulated to be used as highway roadbed material or other uses, or its chemistry may be modified to provide a new glass that can be processed into other glass and/or glass ceramic materials. These may include high temperature fibers or high strength fracking beads or alkali free concrete components and structures, and the such. Finally, to prolong the operational life of body 12, refractory material 34 provides a layer of thermal protection to the inside walls of body 12 while water jacket 35 positioned outside and about body 12 operates to cool body 12. Examples of possible refractory materials include mullite brick, zircon brick, alumina bubble brick, sillimanite brick, corundum brick, fireclay brick, high alumina brick, and others.
Upper portion 16 is bounded by glass surface line 20 and roof 36. Any gap between roof 36 and body 12 is sealed by roof seal 37. It is important that upper portion 16 is isolated from the air and air movement outside of body 12. Once glass batch material 18 has melted and has reached a certain temperature the gasification process may begin by feeding organic waste 42 from waste feeder 40 into upper portion 16. Organic waste 42 must be dropped from above glass surface line 20 into an ambient air space that is free from disruptive air movements so that organic waste may freely fall through upper portion 16. As organic waste 42 is falling, upper bubbler ring 44, consisting of a tube that may be supplied with one or more of hydrogen, oxygen, air, or steam along with one or more nozzles that project into body 12, may inject one or more of hydrogen, oxygen, air, or steam into the falling mass of organic waste 42 as part of the gasification process.
About glass surface line 20 is channel 46 to lead melted glass batch material 18 away from body 12 and towards glass melt feeder 60 where glass batch material 18 is then presented to glass production equipment 62. Channel 46 is also used to draw syngas produced by the gasification process occurring in upper portion 16 to travel above glass batch material 18 and into forehearth syngas vent 58. Channel 46 is divided into one or more zones wherein each zone contains one or more electrodes 26 that are controlled independently of electrodes in the remaining zones. As shown in
The composition of glass batch material 18 varies upon the nature of the glass that is to be produced by glass production equipment 62 which includes but is not limited to glass fibers, reflective beads, cleaning and polishing glass beads, glass beads for atomizing and mixing in spray cans, or other products such as fritted glass to be used as strengthening agents in plastic and cement. These compositions have been the subject of many patents including U.S. Pat. Nos. 6,998,361 and 7,189,671 both issued to Albert Lewis. Table 1 discloses typical compositional ranges of oxides for a variety of glass products.
All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
| Number | Date | Country | |
|---|---|---|---|
| 62579051 | Oct 2017 | US | |
| 62490455 | Apr 2017 | US | |
| 62462551 | Feb 2017 | US |
