The present invention relates generally to biomass and waste plastics conversion systems and, more specifically, to biomass and/or waste plastics conversion systems, machines, apparatuses, and related methods that utilize supercritical water (and/or near-supercritical water) to treat and transform naturally occurring polymers and/or man-made synthetic polymers (collectively, organic materials) into smaller hydrocarbon molecules useful as chemical feedstock materials, including liquid transportation fuels and bio-adhesives.
Everyday the Sun pours down onto the Earth a vast quantity of radiant energy that is many, many times greater than the total now used by Mankind. Some of this energy, together with carbon dioxide and water, Nature traps in trees and other plants by conversion (called photosynthesis) into giant chemical molecules, collectively called biomass. The major components (about 60% to 80%) of this mixture are polysaccharides. These are long and substantially linear chains, the individual links of which are simple sugars. The remaining component (about 15% to 25%) is called lignin and is a complex network of joined aromatic rings of the type found in liquid transportation fuels. The energy trapped within plants can be recovered, in part, by breaking down the long chains into their constituent sugar links for subsequent standard fermentation into bioethanol. In contrast, the breakdown of the lignin network can yield simple aromatic compounds—simple aromatic compounds that are especially useful for either (1) direct incorporation/blending into liquid transportation fuels, and/or (2) further synthesis into bio-based phenolic adhesives.
As with all living things, all biomass eventually dies and—through a process called sedimentary diagenesis, which process occurs naturally, over geological time, deep within the Earth—is transformed into a hard, carbonaceous, rock-like fossil material called kerogen. Kerogen, commonly defined as the insoluble macromolecular organic matter dispersed in sedimentary rocks, is by far the most abundant form of organic matter found on Earth. Kerogen, in turn, naturally breaks down over geologic time (via supercritical water reactions occurring deep within the Earth) into lower-molecular-weight hydrocarbon products including bitumen, oil, and natural gas. Kerogen is, therefore, the precursor material of most all fossil fuel and petroleum products currently used by Mankind.
Water, a continuous hydrogen-linked three-dimensional network of self-aligning triatomic H2O molecules, possesses unique, anomalous, and well-studied properties. Water is ubiquitous in Nature, both on Earth and in the Heavens, and commonly exists in solid, liquid, and gaseous form. Water also commonly exists in another much less familiar form (phase of matter) near and beyond its so-called ‘critical point’. This highly energetic and more exotic state of water subsists in the critical and supercritical regions of water's state-space where the physical distinction between gas and liquid largely disappears, and where only a single hot homogeneous equilibrium phase remains. Water, under supercritical conditions—that is, water near and beyond its critical temperature (Tc) and critical pressure (Pc), possesses its own peculiar set of properties that differ substantially from those of ordinary liquid water (water at ambient conditions).
In ordinary water, the critical point is observed to occur at about 647K (374° C. or 705° F.) and 22.06 MPa (3200 psia or 218 atm). In the vicinity about the critical point, the physical properties of water's liquid and vapor phases change abruptly, with both phases becoming substantially the same with properties substantially opposite from those of ordinary liquid water. For example, under ordinary ambient conditions, water is a nearly incompressible liquid that has a low thermal expansion coefficient, a high dielectric constant, and is an excellent solvent for electrolytes. Near and above its critical point, however, all of these properties change into their opposites; water becomes compressible, expandable, a poor dielectric, a bad solvent for electrolytes, and prefers to mix (solvate) with nonpolar gases and is an excellent solvent of organic molecules. Unlike ordinary water, supercritical water can be continuously compressed from gas-like to liquid-like densities while being maintained as a single-phase fluid.
Beginning with the dawn of the Industrial Revolution and through various means, Mankind has mastered the art of extracting natural resources from the Earth, including coal, oil, and natural gas, for his and her further exploitation and benefit. Some of these extracted ‘fossil materials’ are converted (at the chemical factory) into, among other things, an array of different kinds of synthetic polymers called plastics. Among the most commercially significant plastics made by Mankind, polystyrene (PS), polyethylene (PE) and polypropylene (PP), all are made of long polymer chains that contain only carbon and hydrogen atoms in amounts similar to the hydrocarbons found in diesel and gasoline engine fuels. Thus, the molecules in diesel and gasoline are chemically similar to the polymers that constitute many plastics, but are much smaller in size. It has, therefore, been recognized by scientists and chemical engineers that if the long chains of these types of plastics could be broken down into smaller pieces, these moieties could find use as liquid transportation fuels (among other possible uses).
As a consequence of the Industrial Revolution, Mankind now lives in the Age of Plastics. In today's modern era, the continuous influx of waste plastics polluted into Mankind's environment has created a worldwide environmental crisis. To wit, in 2018 alone (and according to the World Economic Forum), an estimated 360 million tons of plastic products were manufactured worldwide. With a rapidly growing world population driving demand, the production of plastics is expected to reach 500 million tons by 2025 and a staggering 619 million by 2030. Of all the plastic waste produced globally, only 9% has ever been recycled—the remainder has been and continues to be discarded (and thus presents an available resource and a huge missed opportunity).
In view of this readily available chemical resource (and according to the American Chemistry Council), investments in chemical recycling of waste plastics in 260 new facilities across the United States would lead to a stronger, more circular economy that would result in (1) 38,500 new jobs supported by new advanced plastic recycling and recovery facilities, (2) $2.2 billion dollars in annual payrolls, and (3) $9.9 billion in U.S. economic output attributable directly to new plastics recycling and recovery operations. Thus, there appears to be substantial justification for investments into advanced plastic recycling and recovery technologies.
Nowadays, and from both legal and scientific perspectives, it has become a generally accepted fact that Mankind's continuous combustion of fossil fuels (and subsequent release of carbon dioxide (CO2) into the Earth's atmosphere) has contributed to global warming. In addition, it is also generally accepted that plastic pollution is a serious environmental concern. Accordingly, it is self-evident that in order to reduce both CO2 emissions (to, hopefully, retard and/or reverse global warming) and plastics pollution, Mankind needs to (1) reduce its reliance on, and use of fossil fuels and fossil material resources, and (2) better use its abundant biomass and waste plastics resources (as preferred alternatives to the use of native fossil materials). In order to achieve these objectives, new technologies are needed that enable the rapid and economic conversion of abundant biomass and waste plastics into smaller more useful chemical fragments—and are able to do so on a large-scale, commercially practical, and energy efficient way. The present invention fulfils these needs and provides for further related advantages.
The present invention is directed to systems, including mobile units sized and configured to fit within standard intermodal cargo containers (so as to be readily transportable by land, rail, and/or sea), that enable the rapid and economic conversion of solid biomass and/or waste plastic materials (i.e., organic materials) into smaller liquid and gaseous hydrocarbon molecules—smaller hydrocarbon molecules that, in turn, are useful as chemical feedstock materials including, for example, liquid transportation fuels and bio-adhesives. The innovative systems and mobile units disclosed herein (aka “supercritical hydrocyclotrons”) comprise, in combination, (1) a supercritical water (or near-supercritical water) treatment system for converting organic materials into smaller hydrocarbon molecules, and (2) a hydrocyclonic separation system for recovering the smaller hydrocarbon molecules from the combined water/hydrocarbon effluent. As disclosed herein, the supercritical water treatment system is capable of harnessing the remarkable powers of supercritical water (SCW) in a highly controlled manner to achieve rapid biomass/waste plastics hydrothermal liquefaction with near zero char formation, whereas the accompanying hydrocyclonic separation system is capable of continuously separating the resulting liquified and/or gaseous biomass/waste plastics fragments (i.e., smaller hydrocarbon molecules) from the combined hot flowing water/hydrocarbon mixture effluent. Plainly put, organic materials are fed into the supercritical hydrocyclonic system, broken down via supercritical water reaction into smaller more valuable hydrocarbon molecules, which, in turn, are recovered via hydrocyclonic separation for subsequent re-sale (e.g., to the chemical factory, petroleum refinery, and/or advanced integrated biorefinery—as the case may be).
In a preferred embodiment and in a first aspect, the present invention is directed to a ‘supercritical hydrocyclotron’ for transforming one or more selected organic materials into a plurality of reaction products via supercritical or near-supercritical water reaction. As disclosed herein, the innovative supercritical hydrocyclotron of the present invention comprises, in fluidic series: (1) an extruder having an inlet and a downstream outlet, wherein the downstream outlet is coincident with the longitudinal axis of the extruder; (2) a steam generator fluidically connected to a downstream inlet manifold, wherein the inlet manifold forms a circular ring having a plurality of inwardly facing exit portals, wherein the plurality of exit portals is circumferentially positioned about the inner surface of the ring; (3) a tubular reactor having an interior space fluidically connected to an inlet end and an outlet end, wherein the inlet end of the tubular reactor is adjacent and fluidically connected to both (i) the outlet of the extruder, and (ii) the plurality of circumferentially positioned exit portals of the inlet manifold.
As further disclosed herein, the inlet end of the reactor further comprises an axially aligned occlusion (preferably cone-shaped) having one or more through-holes or passageways (to allow passage of the molten extrudate/water mixture). The tubular reactor is configured such that, under operating conditions, a flowing molten polymeric (organic material) extrudate exiting the outlet of the extruder and entering into the interior space of the tubular reactor is spread out and thinned by the cone-shaped occlusion while simultaneously being radially impinged upon (struck) by continuously flowing hot compressed water and/or supercritical water that is exiting the plurality of circumferentially positioned exit portals (to thereby yield the plurality of hydrocarbon reaction products mixed with water). For purposes of enhanced conceptualization, this configuration may be thought of as an extremely hot circular shower that is forcefully and inwardly showering a central and cylindrically flowing molten extrudate with SCW, while the flowing molten extrudate is being spread out and thinned by the hard surface of a tip section of an axially cone-shaped obstruction (thereby ensuring rapid and complete mixing of the target organic material with hot compressed water and/or supercritical water).
As still further disclosed herein and in a second aspect, the outlet end of the tubular reactor is fluidically connected to: (4) an expansion chamber (for cooling and initial coalescing of the hydrocarbon reaction products), which, in turn is fluidicly connected to (5) a hydrocyclonic separator, wherein the hydrocyclonic separator is configured to spin and substantially separate the plurality of hydrocarbon reactions products from the water and comprises, in fluidic series, (i) a cyclindrical swirl chamber section, (ii) a concentric tapered reducing section, and in some preferred embodiments (iii) a cylindrical tail section. Under operating conditions, the plurality of hydrocarbon reaction products mixed with water exiting the expansion chamber enters into the cyclindrical swirl chamber section (of the hydrocyclonic separator) through a tangential inlet and creates a flowing vortex with a reverse-flowing central core (all within the hydrocyclonic separator). The plurality of hydrocarbon reaction products exits the hydrocyclonic separator through an axially aligned reaction products ejection port located on the cyclindrical swirl chamber section, whereas the water exits the hydrocyclonic separator through an axially aligned tail section outlet (and is preferably re-used as feed water to the steam generator).
In further embodiments and in a third aspect, the system further comprises a movable (adjustably extendable) ram centrally positioned within the tubular reactor. The ram (which may take the form of a rod or piston) is movable back and forth within and along the longitudinal axis of the tubular reactor to thereby quickly increase or decrease the volume of the interior space of the tubular reactor. In this way, the residence or reaction time of the supercritical water reaction occurring within the tubular reactor (during operation of the system) may be selectively and readily changed (with longer residence times corresponding to larger reactor volumes). This ‘on-the-fly’ changeability of the reactor volume advantageously allows ‘tuning’ of the molecular-weight-distribution of the resulting hydrocarbon reaction products (with gaseous and lower molecular-weight-distributions corresponding to longer residence times).
In another preferred embodiment, the present invention is directed to a method for converting solid biomass and/or waste plastic materials (organic materials) into smaller liquid and gaseous hydrocarbon molecules by means of the inventive supercritical hydrocyclotrons disclosed herein, the inventive method comprising the steps of: (1) conveying the solid biomass and/or waste plastic materials through a conveyor (e.g., an extruder or other suitable pump) and into a downstream tubular reactor that comprises an axially aligned occlusion (preferably cone shaped) having one or more through-holes or passageways, wherein the occlusion is configured to spread and thin the solid biomass and/or waste plastic materials; (2) generating supercritical water or near-supercritical water substantially free of salts and minerals; (3) conveying the supercritical water or near-supercritical water into a downstream inlet manifold, wherein the inlet manifold forms a ring having a plurality of inwardly facing exit portals, wherein the plurality of exit portals is circumferentially positioned about the inner surface of the ring; (4) ejecting the supercritical water or near-supercritical water through the plurality of exit portals circumferentially positioned about the inner surface of the ring and into the tubular reactor and about the occlusion such that the supercritical water or near-supercritical water strikes and reacts with the solid biomass and/or waste plastic materials to yield the plurality of hydrocarbon reaction products mixed with water; and (5) substantially separating the plurality of hydrocarbon reactions products from the water by creating a flowing vortex with a reverse-flowing central core within a hydrocyclonic separator, and then removing the plurality of hydrocarbon reaction products from the hydrocyclonic separator through an axially aligned reaction products ejection port while simultaneously removing the water through an axially aligned tail section outlet.
In accordance with the biomass and/or waste plastic material liquefaction (and/or gasification) methods disclosed herein, a specialized single screw extruder is preferably utilized to convey, while heating and increasing pressure from atmospheric to about or greater than 22.06 MPa (3200 psia or 218 atm), a selected solid biomass and/or waste plastic feedstock organic material from an upstream hopper to a downstream tubular reactor. The selected feedstock organic material becomes heated, pressurized, and plasticized/moltenized (i.e., turns into a semi-solid molten state) while travelling down the heated barrel of the extruder before exiting through a specialized extruder outlet (or die). The extruder outlet, in turn, is fluidically connected (via a specialized metering valve) to an adjacent inlet manifold that, in turn, includes a plurality of circumferentially positioned and inwardly directed exit ports. The exit ports are configured to circumferentially inject supercritical or high-energy water into the tubular reactor such that the water impinges upon (strikes) the molten feedstock organic material (that is flowing centrally therethrough during operation of the system). A novel cone-shaped occlusion (having a plurality of reactant flow through-holes or passageways positioned about a base plate of the cone portion) is centrally positioned and axially aligned at the reactor's front end to facilitate spreading and thinning of the centrally flowing molten feedstock material (as the material flows over the tip of the cone), thereby enabling the near-instantaneous penetration and mixing of the centrally flowing molten feedstock material with regulated (or minimum) amounts of supercritical/high-energy water.
The reaction times within the variable volume flow-through SCW reactor may be, in some embodiments, controlled by adjustably and/or selectively positioning the ram (centrally positioned within the tubular reactor) to either contract (“ram-in”) or expand (“ram-out”) the volume of the otherwise tubular reaction chamber. In other embodiments, the length of the ram is preselected and nonadjustable.
In still further embodiments, a circumferentially positioned, high efficiency alternating current induction coil (that is part of an induction heater) surrounds the tubular reactor and supplies additional heat energy when needed (for example, to maintain steady state conditions during operation of the system). Similarly, a plurality of outer heating bands is positioned about the barrel of the extruder for preheating the selected feedstock material (as the organic material travels down the barrel of the extruder). In this way, a minimum amount of water is conveyed, heated, pressurized and used for reaction and liquefaction (and/or gasification). Moreover, the reaction (residence) time may be appropriately adjusted (tuned) to accommodate different types of polymeric material feedstocks.
These and other aspects of the present invention will become more evident upon reference to the following detailed description and accompanying drawings. It is to be understood, however, that various changes, alterations, and substitutions may be made to the specific embodiments disclosed herein without departing from their essential characteristic or scope.
The drawings are intended to be illustrative and symbolic representations of certain exemplary embodiments of the present invention and as such they are not necessarily drawn to scale. In addition, it is to be expressly understood that the relative dimensions and distances depicted in the drawings (and described in the “Detailed Description of the Invention” section) are exemplary and may be varied in numerous ways. Finally, like reference numerals have been used to designate like features throughout the several views of the drawings.
In view of the foregoing,
The present invention is directed to supercritical hydrocyclotronic systems capable of converting solid biomass and/or waste plastic materials (i.e., organic materials) into smaller liquid and gaseous hydrocarbon molecules—smaller hydrocarbon molecules that, in turn, are generally useful as chemical feedstock materials including, for example, liquid transportation fuels and bio-adhesives. Unlike known SCW conversion schemes that mix liquid water together with a target reagent (organic material) before heating (thereby using excessive amounts of water, as well as energy to heat and pressurize the same), the novel supercritical hydrocyclotronic systems of the present invention heat the liquid water and target reagent (organic material) separately and then forcefully mixes them together in a specialized tubular reactor (wherein the heated supercritical or near-supercritical water is controllably injected about and into the target organic material that has already been pre-heated and is continuously flowing therethrough). In this way, the use of a highly regulated (or minimum) amount of water for reaction with, and liquefaction and/or gasification of, a wide selection of organic materials is made possible. In addition, the volume (and residence time) of the novel SCW reactor disclosed herein is selectively adjustable (tunable) to enable the selective altering and/or tuning of the distribution of the resulting hydrocarbon molecules produced by supercritical water reaction (with longer residence times generally resulting in smaller molecular fragments).
Advantageously, the novel supercritical hydrocyclotronic systems of the present invention are able to convert, in a very energy efficient way, a wide range of organic materials into valuable chemical fragments (without any significant char formation) within seconds (generally less than 10 seconds). The supercritical hydrocyclotronic systems disclosed herein (including mobile units thereof) thus enable the economic utilization of abundant biomass and waste plastics as viable renewable feedstocks (as opposed to native fossil fuel derived feedstocks) for conversion into alternative liquid transportation fuels and valuable green-chemical products.
Referring now to
As shown in
More specifically, and as depicted in the process flow diagram of
During operation of the supercritical hydrocyclotronic system 10, the selected organic material is continuously fed into the extruder 110 by means of the hopper 115—the feed material is then heated, pressurized, and becomes molten as it is conveyed from the inlet 112 to the downstream outlet 114. The speed of rotation of the inner screw 110b (which is governed by the motor) controls the flow rate of the molten extrudate. In certain embodiments, the plasticized/molten extrudate exiting the downstream outlet 114 of the extruder 110 is in the form of a continuously flowing cylinder of molten polymeric material (which, conceptually, may be thought of as being similar to a continuous spaghetti noodle exiting a pasta maker). Note: the term “extrudate” as used herein shall be broadly construed to encompass all materials that are pushed through a small opening or die, and is not limited to materials exiting the end of an extruder.
As further depicted in the process flow diagram of
Referring now to
In certain preferred embodiments, the various components that comprise the system 10 are each made of type 316 stainless steel and/or a nickel/chromium alloy because of the superior resistance to corrosion these metals possess.
As still further depicted in the process flow diagram of
As shown, the tubular reactor 512 further comprises an inlet manifold 520 for evenly distributing the supercritical or high-energy water produced by the steam generator 216 about and into the molten extrudate (exiting the downstream outlet 114 of the extruder 110). As best shown in
As generally shown in the various views associated with
The cone-shaped flow-through occlusion 528 facilitates spreading and thinning of the centrally flowing molten extrudate (as the extrudate flows over the cone tip and then through the reactant flow through-holes 528a) during operation of the system 10. In other embodiments, the flow-through occlusion 528 takes the form of a hem i-spherical dome or even a flat plate having one or more holes or adjacent passageways. In this configuration, near-instantaneous liquefaction (and/or gasification) is achieved due to the regulated penetration and mixing of the molten target feedstock material with controlled or minimum amounts of supercritical water or high-energy water (to yield the plurality of hydrocarbon reaction products mixed with water).
As shown in the embodiments represented in
The novel tubular reactor 512, in some embodiments, further comprises a movable ram 516 centrally positioned within the tubular reactor 512. The ram 516 (which may be in the form of a piston or rod and is sometimes referred to as a “spear”) is movable back and forth (via a ram actuator—not shown) within and along the longitudinal axis of the tubular reactor 512 (to thereby increase or decrease the volume of the interior space 512a). In this way, the residence time of the supercritical water reaction occurring within the tubular reactor 512 (during operation of the system 10) may be selectively and dynamically controlled (with longer residence times corresponding to larger reactor volumes). Finally, an annular manifold reaction products outlet space 520 is positioned about the outlet end 512c of the tubular reactor 512. The reaction products outlet space 520 is fluidicly connected to the interior space 512a (plenum) (of the tubular reactor 512) by way of the plurality of reactor flow channels 515.
As still further depicted in
In still other embodiments and as depicted in
As best shown in
During operations of the system 10, the combined hot flowing hydrocarbon products/water mixture effluent enters the cyclindrical swirl chamber section 418 through the tangential inlet 426 and swirls about the vortex finder 429, thereby creating a high-velocity vortex with a reverse-flowing central core. The hydrocarbon/water mixture accelerates as it flows through the concentric tapered reducing section 420, and continues at a near constant rate through the cyclindrical tail section 424. Centripetal forces cause the less dense hydrocarbon molecules to move toward the low-pressure central core, where axial reverse flow occurs.
In other embodiments, the supercritical hydrocyclotronic systems 10 of the present invention are sized and configured to fit, and be contained within, standard “intermodal” shipping or cargo containers (not shown) (and are thus readily transportable by way of ship, rail and/or truck to most locations throughout the world). Intermodal shipping containers are built to standardized dimensions, and can thus be loaded and unloaded, stacked, transported efficiently over long distances, and transferred from one mode of transport to another—container ships, rail and semi-trailer trucks—without being opened. An intermodal shipping container is generally defined as a standardized reusable steel box used for the safe, efficient and secure storage and movement of materials and products within a global containerized intermodal freight transport system. “Intermodal” indicates and means that the container can be moved from one mode of transport to another (from ship, to rail, to truck) without unloading and reloading the contents of the container. Lengths of containers, which each have a unique ISO 6346 intermodal reporting mark, vary from 8 feet (2.438 m) to 56 feet (17.07 m) and heights from 8 feet (2.438 m) to 9 feet 6 inches (2.9 m) and are all encompassed within the scope of the present invention.
While the present invention has been described in the context of the embodiments illustrated and described herein, the invention may be embodied in other specific ways or in other specific forms without departing from its full scope. Therefore, the described embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are to be embraced within their full scope.
This application is a continuation-in-part of U.S. application Ser. No. 15/943,691 filed on Apr. 4, 2018 (now U.S. Pat. No. 10,421,052), which application is a continuation-in-part of U.S. application Ser. No. 14/549,508 filed on Nov. 20, 2014 (now U.S. Pat. No. 9,932,285), which application is a continuation-in-part of U.S. application Ser. No. 13/297,217 filed on Nov. 15, 2011 (now U.S. Pat. No. 8,980,143), which application claims the benefit of priority to U.S. application Ser. No. 12/828,102 filed on Jun. 30, 2010 (now U.S. Pat. No. 8,057,666) and U.S. application Ser. No. 12/402,489 filed on Mar. 11, 2009 (now U.S. Pat. No. 7,955,508), which applications claim the benefit of priority to U.S. Provisional Application No. 61/110,505 filed on Oct. 31, 2008, and to U.S. Provisional Application No. 61/035,380 filed on Mar. 11, 2008, all of which applications are all incorporated herein by reference in their entireties for all purposes.