US20110233067A1

US20110233067A1 - Electrochemical processing of fluids

Info

Publication number: US20110233067A1
Application number: US12/890,659
Authority: US
Inventors: Arthur C. Lind; Ru T. Wang; Clyde Parrish; Neil Ginther; Jed Aten; Jan Surma; Jerry Weinberg; William R. Aten
Original assignee: CONYERS Tech GROUP LLC
Current assignee: RF ADVANCED TECHNOLOGY GROUP LLC; CONYERS Tech GROUP LLC
Priority date: 2009-09-25
Filing date: 2010-09-25
Publication date: 2011-09-29
Also published as: WO2011038307A1

Abstract

An electrochemical process and device for the controlled and uniform heating of electrically-conductive fluids, the process or device having at least one reactor and at least one power source with at least one electrode and at least one additional conductive material for direct heating of the fluid and for producing electrochemical changes of the fluid to result in at least one property change of the fluid and at least one product.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from co-pending U.S. Provisional Application Ser. No. 61/246,084 filed Sep. 25, 2009, which is titled “METHODOLOGIES AND SYSTEMS FOR HEATING FLUIDS” which is hereby incorporated by reference, co-pending U.S. Provisional Application Ser. No. 61/246,086 filed Sep. 25, 2009, which is titled “METHODOLOGIES AND SYSTEMS FOR HEATING FLUIDS” which is hereby incorporated by reference, co-pending U.S. Provisional Application Ser. No. 61/328,148 filed Apr. 26, 2010, which is titled “METHODOLOGIES AND SYSTEMS FOR HEATING FLUIDS IN A CONTINUOUSLY CIRCULATING SYSTEM” which is hereby incorporated by reference, co-pending U.S. Provisional Application Ser. No. 61/346,874 filed May 20, 2010, which is titled “METHODOLOGIES AND SYSTEMS FOR HEATING FLUIDS IN A FLOW THROUGH SYSTEM” which is hereby incorporated by reference, and co-pending U.S. Provisional Application Ser. No. 61/358,156 filed Jun. 24, 2010, which is titled “METHODOLOGIES AND SYSTEMS FOR HEATING FLUIDS IN A HIGH PRESSURE BATCH REACTOR” which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

High-temperature and high pressure chemical processes, such as those involving supercritical water in a continuous flow reactor, require that the pipes through which the fluid flows have thick walls to withstand the high pressures and temperatures. The fluid being processed is heated by heating the exterior of the pipe, so it is difficult to control the fluid temperature because of the thick pipe wall. It is especially difficult to control the temperature for larger throughputs, which require larger diameter pipes with larger wall thicknesses. Larger throughputs also require rapid heat transfer from the pipe wall to the fluid, which in turn require that the interior of the pipe wall be at a temperature much larger than the required process temperature. The end result is that a high quality product is difficult to maintain and in some cases an over-reacted product can foul the reactor, necessitating shut down and expensive repair and cleaning. Thus, it is desired to directly heat the fluid so that its temperature could be precisely and quickly controlled.

SUMMARY OF THE INVENTION

The present invention enables the controlled electric heating of electrically conductive fluids, for example, liquids in a pipe. The heating occurs by direct interaction of applied electric fields with the fluid. The invention can be used for chemical processing of a variety of liquids and other fluids at very high temperatures and pressures, such as supercritical water. One exemplary embodiment of the present invention comprises a fluid processing device comprising at least one reactor having an interior reactor surface and an exterior reactor surface, at least one applicator comprising at least one power source and at least one electrode and at least one additional conductive material for direct heating of a feedstock and for producing electrochemical changes in the feedstock, wherein the direct heating causes at least one property change of the feedstock.
Another exemplary embodiment of the present invention comprises an electrochemical processing system consisting of one or more power sources, one or more electrodes and at least one additional conductive material in contact with an electrically conductive fluid to be processed, wherein the fluid is contained within a closed containment vessel for batch processing or in a pipe for continuous flow-through processing, the vessel or pipe being made of materials able to withstand supercritical temperatures and pressures wherein the electric field passes between the electrode and the additional conductive material throughout the fluid to heat the fluid to temperatures as high as supercritical to enhance the reactivity of the process.
Another exemplary embodiment of the present invention comprises an electrochemical process for promoting reactions in a fluid by applying an electric field to the fluid that causes direct and uniform heating of the fluid to any desired temperature and pressure, even up to and beyond supercritical domain, as well as causing electrochemical reactions to produce the sought after property changes of the fluid, wherein the temperature, power, frequency, time and flowrate may be varied.
Another exemplary embodiment of the present invention comprises a process for heating a fluid to any desired temperature and pressure up to and beyond supercritical domain by applying an electric field through which the current of the electric field causes direct heating of the fluid to change properties of the fluid.
Another exemplary embodiment of the present invention comprises a process for heating a fluid by applying an electric field through which the current of the electric field causes direct heating of the fluid to change properties of the fluid and the heating causes physical and chemical reactions to take place such that products are produced that did not exist in the fluid prior to heating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cross sectional view of an exemplary embodiment heating device 100 of the present invention;

FIG. 2 illustrates a perspective view of several basic parts that can be used in heating device 100 of the present invention;

FIG. 3 illustrates a perspective view of basic parts to illustrate how they could be arranged to fit into heating device 100;

FIG. 4 illustrates a cross sectional view of a heating device 110 to illustrate how parts can be added to improve the uniformity of heating;

FIG. 5 illustrates a cross sectional view of a heating device 120 to illustrate how different kinds of parts can be combined to improve the uniformity of heating;

FIG. 6 illustrates a cross sectional view of a heating device 130 to illustrate how different kinds of parts can be combined along the length of the pipe to improve the uniformity and utility of heating;

FIG. 7 illustrates an exemplary embodiment with fluid circulation path without circulating pump based on changes in fluid densities;

FIGS. 8A and 8B illustrate exemplary embodiment RF reactors;

FIG. 9 illustrates an exemplary continuous flow fluid heater system with central electrode as the heating element with ceramic spacers for electrical insulation;

FIG. 10 illustrates a schematic drawing of a coaxial applicator used in an exemplary embodiment;

FIG. 11 illustrates an exemplary embodiment of high pressure reactor;

FIG. 12 illustrates exploded view of high pressure reactor;

FIG. 13 illustrates an assembled cross-sectional view of an exemplary embodiment rotating high pressure reactor with cooling attachment in place; and

FIG. 14 illustrates an exemplary embodiment high pressure reactor in vertical and rotated positions.

DETAILED DESCRIPTION OF THE INVENTION

To promote an understanding of the principles of the present invention, descriptions of specific embodiments of the invention follow and specific language is used to describe the specific embodiments. It will nevertheless be understood that no limitation of the scope of the invention is intended by the use of specific language. Alterations, further modifications, and such further applications of the principles of the present invention discussed are contemplated as would normally occur to one ordinarily skilled in the art to which the invention pertains.
FIG. 1 illustrates a cross sectional view of an exemplary embodiment heating device 100 of the present invention. FIG. 2 illustrates a perspective view of several basic parts that can be used in heating device 100 of the present invention. FIG. 3 illustrates a perspective view of basic parts to illustrate how they could be arranged to fit into heating device 100. FIG. 4 illustrates a cross sectional view of a heating device 110 to illustrate how parts can be added to improve the uniformity of heating. FIG. 5 illustrates a cross sectional view of a heating device 120 to illustrate how different kinds of parts can be combined to improve the uniformity of heating. FIG. 6 illustrates a cross sectional view of a heating device 130 to illustrate how different kinds of parts can be combined along the length of the pipe to improve the uniformity and utility of heating. FIG. 7 illustrates an exemplary embodiment with fluid circulation path without circulating pump based on changes in fluid densities. FIGS. 8A and 8B illustrate exemplary embodiment RF reactors. FIG. 9 illustrates an exemplary continuous flow fluid heater system with central electrode as the heating element with ceramic spacers for electrical insulation. FIG. 10 illustrates a schematic drawing of a coaxial applicator used in an exemplary embodiment. FIG. 11 illustrates an exemplary embodiment of high pressure reactor. FIG. 12 illustrates exploded view of high pressure reactor. FIG. 13 illustrates an assembled cross-sectional view of an exemplary embodiment rotating high pressure reactor with cooling attachment in place. FIG. 14 illustrates an exemplary embodiment high pressure reactor in vertical and rotated positions.
The present invention enables controlled heating of electrically conductive fluids e.g. gases, pastes, suspensions, plasmas, slurries and liquids, as we let such a fluid flow (or rest) in a pipe/reservoir/chamber/reactor, or similar vessel. As discussed herein, the term pipe may be used interchangeably with any of the terms discussed above as the particular device/embodiment requires. A Multi-Frequency (MF) heating concept may be applied for power to one or more elements of the system that is electrically insulated from other elements that are electrically grounded. The applied power can be direct current (DC) or alternating current (AC) and/or electromagnetic frequencies making use of any and all frequencies that are permitted and available including, but not limited to, those in the RF range. Various elements that are part of the insulating system or added as part of the internal components may provide direct and indirect heating of the fluid contained in the system. Insulators, seals, and mechanical supports may be required to hold the device together and in alignment under high fluid pressure. Dimensional changes in materials caused by increasing or decreasing temperatures can be taken into account using standard methods that are known to those skilled in the art.
The power source causes electric current to flow through the fluid and heat it to high temperatures. The heating occurs by the direct interaction of applied electric fields with the fluid. The frequency is selected to match the conductivity and/or dielectric property of the fluid. The optimum power for the source depends on the diameter of the pipe, shape and dimensions of the electric conductors and insulators, and the dielectric properties of the fluid among other factors. The power required for the source also depends on the specific heat of the fluid, its flow rate, the thermal insulation used around the pipes and the desired temperature of the fluid.
FIG. 1 illustrates an exemplary embodiment of the present invention for a power source/electric source/heating element or standalone system device 100 that is installed collinear with the pipe whose contained fluid 4 is to be heated. The device is connected to the pipe by means of two flanges 7. Fluid 4 to be heated flows through two pipes 1 a, 1 b, single pipe 2 and two electric insulators 3. Seals 5 prevent leakage of enclosed fluid 4. Note that the raw fluid (i.e., pretreated and/or preheated) is referred to herein as feedstock and the post treatment fluid is referred to as product. Electrical power source 8 may be connected between central pipe 2 and two pipes 1 a and 1 b. Two pipes 1 a, 1 b are connected to building ground 9, which also grounds flanges 7. An electric shield 10 is electrically connected to and surrounds flanges 7. The shield is included for safety reasons as well as to limit radiation from electric source 8 causing electrical interference to electronic equipment. A thermocouple 6 is located at the downstream end to monitor fluid 4's temperature. The output of the thermocouple is connected to a controller 11 to control the output of electrical power source 8 to maintain the desired temperature. Not shown in FIG. 1 are the detailed nature of insulators 3, seals 5, nor the mechanical supports required to hold the device together that may have to operate under high fluid pressure and accommodate dimensional changes caused by changing temperatures; these are standard methods that are known to those skilled in the art.
In further detail, still referring to the embodiment of FIG. 1, the diameter and wall thickness of pipes 1 a, 1 b, 2 are chosen to match those of the system into which it is installed.
Electric insulators 3 electrically isolate center pipe 2 from the adjacent pipes 1 a, 1 b. The material used for electric insulators 3 is chosen to withstand the temperatures and pressures of fluid 4 being heated, such as materials including, but not limited to, high temperature polymers and ceramics. The length of electric insulators 3 is adjusted to alter the heating pattern over the cross section of pipe 1 a, 1 b, 2. Shorter insulators 3 cause greater heating near pipe 1 a, 1 b, 2 walls and longer insulators 3 cause the heating to extend more towards the center of pipe 1 a, 1 b, 2 to provide more uniform heating of fluid 4.
Seals 5 can be made of ceramics, high temperature polymers or high temperature polymer composites incorporating inorganic fibers to add strength, as well as other materials, and are chosen so that they may not be easily corroded by fluid 4. Seals 5 can be any shape, such as washer-shaped or toroidal-shaped. They can be at the ends of insulators 3, on the outer surface of insulators 3 or on the inner surface of insulators 3 depending on whether insulators 3 are in line with the pipe, inside the pipe outside the pipe.
To aid in the following description, five regions are defined for later reference. Region 50R is before upstream insulator 3. Region 60R is at upstream insulator 3. Region 70R is between upstream and downstream insulators 3. Region 80R is at downstream insulator 3. Region 90R is after downstream insulator 3. Electric source 8 causes electric current to flow through fluid 4 between regions 50R and 70R and also between regions 70R and 90R. This electric current heats fluid 4 directly because of fluid 4's electrical conductivity or equivalently its dielectric loss properties. The specifications for electric source 8 depend upon the type of fluid 4 being heated, its flow rate and the temperature to which it is to be heated as well as other factors. For highly conductive fluids, such as salt water, a low frequency alternating current source can be used. Less conductive fluids require higher frequency alternating current sources. The optimum frequency depends on various factors including, but not limited to, the dielectric properties of fluid 4. A number of commercial power sources are available that can be used. The optimum voltage for electric source 8 depends on the diameter of pipe 1 a, 1 b, 2, length of electric insulators 3 as well as the dielectric properties of fluid 4. The power required for electric source 8 depends on the specific heat of fluid 4, its flow rate, the thermal insulation used around pipes 1 a, 1 b, 2, and the desired fluid 4 temperatures. If the power required exceeds the power levels of any single commercially available electric source, two or more heating devices 100 and their associated electric power sources can be installed along the pipe to achieve the required power level.
Thermocouple 6 allows measurement of fluid 4's temperature immediately after it has been heated. Fluid 4 temperature may be kept at the desired value by using this measured temperature to control the power level of electric source 8 using standard commercially-available controllers 11.
The electric current flow pattern is now discussed. When insulators 3 are short, the current flow occurs mostly close to the pipe walls in regions 60R and 80R and only a short distance upstream and downstream of these regions. This causes greatest heating near the pipe walls close to insulator 3. For turbulent fluid 4 flows, mixing occurs and fluid 4 can be uniformly heated. For laminar flow, where the fluid flow is slow at the walls of the pipe and rapid near the center of the pipe and little or no mixing occurs, fluid 4 may become overheated at the pipe wall. This overheating at the pipe wall can be significantly reduced by increasing the length of insulators 3 to cause the electric current flow to move more towards the center of the pipe. However, because of the velocity profile for laminar flow of fluid 4, the heating can still be excessive at the pipe wall. This embodiment may include a number of different parts that can be added to produce uniform heating of fluid 4 by improving the electric current flow pattern and by physical mixing of the fluid before, during and/or after it is heated, as described below.
FIG. 2 shows various exemplary basic parts that can be used in various embodiments, including heating device 100, of the present invention to alter the electric current flow pattern to bring more electric current flow to the center of the pipe and/or to cause mixing of fluid 4 to promote more uniform heating of fluid 4. These parts could be fastened inside the pipes by welding or other means.
Basic part 140 consists of two flat metal plates intersecting at right angles about their center lines. The size of the part may be such that it may snuggly fit into pipes 1 a, 1 b, 2 and be held in place by welds or other means although the size, configuration, and positioning of the parts may be varied to other arrangements. This basic part can be modified by making the front and/or rear ends different shapes, such as, for example, sharp points, blunt points, or rounded curves for the purpose of altering the electric field pattern. Basic parts similar to part 140 having three or more intersection plates can also be used to improve the electric current pattern. The length, placement and angular orientation of part 140 along pipes 1 a, 1 b, 2 may be chosen to provide the best uniformity of heating.
Basic part 141 is may be described as two intersecting flat metal plates that have been deformed so that their outer edges form four helices. The helices shown in FIG. 2 have an 80 degree right hand twist, but greater and lesser degrees of twist can be used. Right and left handed helices can be used. As in part 140 the front and rear ends can have a variety of different shapes, such as points or smooth curves. The height, width, length, placement and orientation of part 141 along pipes 1 a, 1 b, 2 may be chosen to provide the best uniformity of heating and fluid mixing. When the part stands alone with no other support, its height and width may be such that it fills the interior of pipe 1 a, 1 b, 2 and is held in place by welds or other means. Part 141 has the same electrical function as part 140, but it also promotes physical mixing of the heated fluid 4 to provide more uniform heating. Part 141 can have more than two intersecting plates, such as three, four or more.
Basic part 142 consists of parallel metal plates; seven are shown, but other numbers can be used. The planes of the plates are parallel to the axis of pipe 1 a, 1 b, 2 so fluid 4's flow is not disturbed. This basic part can be modified by making the front and/or rear ends different shapes, such as sharp points, blunt points, or rounded curves for the purpose of altering the electric field pattern. The length, placement and orientation of part 142 along pipes 1 a, 1 b, 2 are chosen to provide the best uniformity of heating.
Basic part 143 is similar to part 142 except that the metal plates are not parallel to the axis of pipe 1 a, 1 b, 2. The reason for their not being parallel to the axis of pipe 1 a, 1 b, 2 is to alter the direction of fluid 4 flow to cause physical mixing of fluid 4 and thereby improve uniformity of heating. The sketch of basic part 143 shown in FIG. 2 shows all plates parallel to one another, but this need not be the case. The plates can also be curved to promote mixing. This basic part can be modified by making the front and/or rear ends different shapes, such as sharp points, blunt points, or rounded curves for the purpose of altering the electric field pattern. The plates can be of different lengths along pipe 1 a, 1 b, 2 and different angles to the axis of pipe 1 a, 1 b, 2 to increase physical mixing. The length, placement and orientation of part 143 along pipes 1 a, 1 b, 2 are chosen to provide the best uniformity of heating and fluid mixing.
Basic part 144 is similar to parts 142 and 143, except that it incorporates intersecting metal plates.
Basic parts 145 and 146 may be described as auger-shaped metal disks. Part 145 is right handed and part 146 is left handed. The pitch of the auger can be selected for best physical mixing of fluid 4. In addition to providing mixing, parts 145 and 146 may function to bring the electric current flow from pipe 1 a, 1 b, 2 walls to the center of pipes 1 a, 1 b, 2. The diameter, pitch, handedness placement and orientation of parts 145 and 146 along pipes 1 a, 1 b, 2 may be chosen to provide the best uniformity of heating and fluid mixing. When parts 145, 146 stand alone with no other support, their diameters may be chosen to fill the interior of pipe 1 a, 1 b, 2 so they can be held in place by welds or other means.
Part 147 is a metal cylinder that could be placed along the axis, or other location, of pipes, 1 a, 1 b, 2 and held in place in a variety of means. In some embodiments, the cylinder may be combined with one of the above-mentioned parts by welding or other means. For example, cylinder part 147 could be combined with either part 140 or 141 with the cylinder axis along the intersection of the metal plates forming parts 140 or 141. Another exemplary combination is to combine cylinder part 147 with one or more auger-shaped parts 145 or 146. In these embodiments, cylinder part 147 could run through the center of one or more of parts 145 or 146. The ends of cylinder part 147 could be of any suitable configuration and geometry including, but not limited to, flat, pointed or curved. Its purpose is to improve uniformity of heating as well as promote physical mixing of fluid 4.
Basic part 148 may be shaped as the frustum of a conical cone similar to part 147. As with part 147, part 148 may be held in place by combining it with other basic parts. The ends of cylinder part 148 could be of any suitable configuration and geometry including, but not limited to, flat, pointed or curved. Its purpose is to improve uniformity of heating as well as promote physical mixing of fluid 4.
FIG. 3 shows several of the parts shown in FIG. 2 arranged in an exemplary configuration to be placed in heating device 100 shown in FIG. 1. Parts made from basic part 140 are shown at the top of FIG. 3. As stated above, this basic part 140 can be modified by making the front and/or rear ends different shapes, as shown in this example. For parts 140-1 and 140-3, corners have been removed on one end. For part 140-2, corners have been removed on both ends. Part 140-1 may be placed in region 50R, Part 140-2 may be placed in region 70R and part 140-3 may be placed in region 90R.
In the middle of FIG. 3 are shown parts based on basic part 142. Part 142-1 may be placed in region 50R, Part 142-2 may be placed in region 70R and part 142-3 may be placed in region 90R.
At the bottom of FIG. 3 are shown parts based on basic parts 145 and 146. Part 145/6-1 may be made of both parts 145 and 146 and may be placed in region 50R. Likewise, part 145/6-2 may be made of both parts 145 and 146 and may be placed in region 70R. Part 145/6-1 may be made of both parts 145 and 146 and may be placed in region 90R. While not shown for parts 145 and 146, in some embodiments, the parts may be used in combination with basic cylinder part 147, which could run through the center of the parts to add support and stability.
To illustrate how the parts described in FIG. 3 may be incorporated into heating device 100 shown in FIG. 1, FIGS. 4, 5 and 6 illustrate how this may be configured. This figure illustrates how several of the basic parts shown in FIG. 2 may be incorporated into heating device 100. Different basic parts can be combined into one part and different disconnected basic parts can be placed in the same region or different regions.
Referring now to FIG. 4, an exemplary embodiment heating device 110 may have several features in common with heating device 100 except that it also incorporates internal parts (which may be comprised of any suitable materials including, but not limited to, metal) similar to basic part 142, which are labeled 142-1, 142-2 and 142-3, as in the top of FIG. 3. As stated above, this basic part 142 has been be modified for this embodiment. The purpose of parts 142-1, 142-2 and 142-3 is to cause the electric current flow that normally flows across insulators 3 in regions 60R and 80R close to the pipe wall, to be moved nearer to the center of the pipe so the heating is more uniform. The electric current flow pattern can be altered by changing the angle and size of the corners removed, by rounding the resulting angular corners and by rotating the electrodes so that the plates in neighboring electrodes do not lie in the same plane and by other modifications. The electric current flow pattern can be further altered by changing the number of plates, having an unequal number of plates in adjacent parts 142-1, 142-2 and 142-3 and by changing the distance between adjacent parts 142-1, 142-2 and 142-3. Part 142-1 may be electrically connected to pipe 2 in region 50R, part 142-2 may be electrically connected to pipe 3 in region 70R and part 142-3 may be electrically connected to pipe 2 in region 90R.
FIG. 5 shows an exemplary embodiment heating device 120 having several features of heating device 100, except that it further incorporates internal parts (which may be comprised of any suitable materials including, but not limited to, metal) such as basic parts 142 and 147, which are labeled 142-4 and 147-1. Basic part 142 consists of parallel plates. Here part 142-4 supports cylindrical part 147-1 with the axis of the cylinder along the center line of pipe 1 a, 1 b, 2. Cylindrical part 147-1 has rounded ends, but they could be other shapes, such as bulbous, to alter fluid 4 flow or increase current flow to the center of the pipe. The combined parts 142-4 and 147-1 are electrically connected to pipe 2 in region 70R. Cylinder part 147-1 extends upstream through region 60R into region 50R. Cylinder part 147-1 also extends downstream through region 80R into region 90R. Thus, the electric current paths that normally flow close to the pipe walls near regions 60R and 80R are brought into the center of pipe 1 a in upstream region 50R as well as into the center of pipe 1 b in downstream region 90R. The diameter and length of cylinder part 47-1 can be chosen to achieve uniform heating of fluids 4 in laminar flow by concentrating the current paths near the axis of the pipe where the flow is normally largest for laminar flow. The presence of the cylinder at the center of the pipe also slows the flow at the axis of the pipe to further achieve uniform heating over the entire cross section of pipe 1 a, 1 b, 2.
FIG. 6 shows an exemplary embodiment heating device 130 that may be an expanded version of heating device 120 shown in FIG. 5. It may comprise two heating devices 120 separated by a section of pipe 1 c. Cylindrical part 147-2 runs through this section of pipe 1 c. The interior of pipe 1 c constitutes region 90R of the upstream device and constitutes region 50R of the downstream device, so it is labeled region 90/50R. As in heating device 120, electric current flow occurs between pipe 2 walls and cylindrical part 147-2 in regions 50R and 90R. In heating device 130, additional currents flow between the pipe 1 c walls and cylindrical part 147-2 in region 90/50R. Pipe 1 c can be made very long to increase the length over which heating occurs. Heating device 130 may be useful for fluids 4 that have small electrical conductivity because the long region 50/90R over which electric current flows may reduce the electrical resistance presented to electric current source 8 so that lower voltages can be used to deliver the required amount of power. To accommodate differential thermal expansion that may occur, either 142-4 or 142-5 may be free to slide along pipe 2 wall.
In another exemplary embodiment, a continuously circulating heating system was constructed to demonstrate the ability of a coaxial electromagnetic heating apparatus (“heating elements”), including, but not limited to, one or more RF heaters, to efficiently heat a fluid contained in a pipe/piping system. The system may operate with or without a circulating pump.
FIG. 7 illustrates an exemplary embodiment without a circulating pump, wherein the fluid may be circulated by using thermal density gradients to circulate the fluid. In this embodiment, the vertical system circuit orientation was designed to demonstrate the ability of RF field to heat a fluid to super critical temperatures yet safely and efficiently contain the fluids at increased temperatures and pressures. The basic principle of operation of this embodiment is based on the change in density of fluids with temperature, i.e., the fluid density decreases when it is heated and the fluid density increases as it cools.
FIG. 8A illustrates an exemplary apparatus illustrating a continuously feed through system 200 with reactor 202, power source 204, and electrode(s) 206 such that fluid may flow continuously, though not circulating. FIG. 8B illustrates an exemplary apparatus illustrating a continuously circulating system 200 with reactor 202, power source 204, electrode(s) 206, sampling valves 208, pressure relief valve 210, reservoir and ballast 212, and sample fill valve 214. The equipment comprises additionally an expansion tank to compensate for the effect caused by the water density decrease as the temperature rises toward the supercritical condition. The incompressibility of water at all density necessitated an expansion chamber to prevent system rupture of the laboratory apparatus. In addition, a pressure vent may be included as a safety device to allow excess pressure to be safely released. It may further be advantageous to include one or more temperature and/or pressure gauges along the flow path as well as a sampling system. Note that in the illustrated embodiment, the RF generator to the electrode may pass through the ceramic tube insulator. A ground connection may be made to the stainless steel circulating system.
The RF electrode(s) may be supported on the ceramic tube that carries the electrical wire to the electrode. At the top of the expansion tank is a fill valve that may be used to add fluids to the reactor. In this embodiment, an RF generator was attached with the positive connection made to the electrode, which is electrically isolated from ground by the ceramic tube, and the ground attachment may be made to the reactor.
Note that, in the illustrated embodiment, there is no need for a circulating pump because the system is gravity driven based on density gradients. In some embodiments, algae circulated through the system under the influence of one or more RF generators (i.e., heating) produced matter in solid form, liquid form and gaseous form. In some embodiments, the fluid, such as algae and water mixtures, could be heated successfully to supercritical conditions wherein the algae could be degraded to methylene chloride and water soluble products.
In some embodiments various algae slurries were heated to supercritical or near supercritical temperatures and the algae slurries were degraded. Further tests were conducted on the products produced including testing by HPLC, GC, and GC-mass spectrometry.
As discussed herein, various embodiments of the present invention may further include one or more pumps to aid in circulating the fluid(s). Such pumps may be present in various locations along the flow path. Such pumps may allow for increased flowrates over embodiments without circulating pumps. In some embodiments, additional reservoirs may be a incorporated to the system to accommodate the influence of such circulating pumps.
In another exemplary embodiment, a flow through heating system was constructed to demonstrate the ability of a coaxial heating apparatus (“heating elements”), including, but not limited to, one or more MF heaters, to efficiently heat a fluid continuously flowing through a pipe/piping system.
In the exemplary embodiment illustrated in FIG. 9, the system is modular with one (or more) heating element(s) and is designed to operate at power levels up to 15 KW though other embodiments may have higher or lower power levels. Illustrated is an exemplary continuous flow reactor 300 with reactor 302, chamber 304, electrode 306, ceramic insulator 308, fittings 310, conductor to power 312, spacer 314, and spacer leg 316. The design illustrated utilizes Swagelok SS seals and features Techlok sealing flanges. This system may utilize ceramic electrical insulators and ceramic spacers to maintain the position of the MF electrode. The system may also have a back flush feature to allow for clearing of any plugging or needed cleaning which is a convenient feature for high production volumes. The heating element is designed with high strength corrosion resistant alloys located in the center of the process fluid flow. This configuration does not rely on heat transfer through thick walls that are required to contain the high pressure required for the processing conditions and makes it possible to completely and separately control the heating of each heating element. Further, its modular design allows replications of this basic heating unit to provide scalability to generate any desired throughput production rate with in-line maintenance or replacement of heating elements or power generators without system shutdown.
Although the illustrated system uses a ceramic tube to provide electrical insulation of the heating element, other embodiments may use existing electrical pass-through technology and feature a corrosion resistant alloy as a protective shroud around the ceramic electrical insulator. This configuration may eliminate pressure and other physical damage problems which could develop and will require only one metal to metal seal for the electrical connection and metal. The other seals may be Techlok sealing flanges, or other suitable flanges. Copper gaskets may be used to connect the heater to the reactor. The illustrated system may also use other pipe sizes and appropriate flanges. The outside of the system may use electric resistance heat tracing and be covered with a high temperature insulation material around the heating elements and components.
As noted above, the system heater can be replicated based on the production rate sought and the capacity of the MF power supplied. The heating units in the illustrated embodiment are approximately 3 ft long and Techlok flanges are used to connect the units. Each heating unit has its own power supply to provide redundancy and control during operations. In some embodiments, the ceramic insulator may be clad with stainless steel. Some embodiments of the insulator may also have graded seals between the stainless steel cladding and the ceramic insulator and between the ceramic insulator and the copper conductor. The power pass-through may be connected with Techlok flanges to the heating element. This exemplary unit is designed to contain 5000 psi at 400° C.
FIG. 10 illustrates another view of a portion of an exemplary embodiment of the present invention showing a schematic view of a coaxial electrode applicator embodiment 400 which is electrically insulated from the piping system, placed in the center of the pipe, and connected to the “hot” side of an MF generator. Illustrated are conductor to power 402, electrode 404, pipe wall 406, and fluid flow 408. The piping system that is electrically insulated for the coaxial electrode is attached to ground.
Such an exemplary embodiment may employ one or more coaxial applicators. Each applicator has two electrodes and the electric current that passes from one electrode to the other electrode directly heats the fluid between them. One electrode is the wall of the pipe that conveys the fluid to be heated. The other electrode is cylindrical and lies on the central axis. The design dimensions of an exemplary embodiment are L=24,″ R=2,″ r=0.5″ for 13.56 MHz RF input power and r=1.25″ for 60 Hz AC input power.
The inner radius of the pipe, R, the radius of the of the central coaxial electrode, r, and its length, L, along with the electrical properties of the fluid determine the electrical impedance of the applicator, which must be within certain ranges to obtain good coupling of power from the RF generator or AC power line to the applicator. Electrical matching networks for RF can provide some compensation, but by careful design, using optimum dimensions, efficient coupling of power can be achieved. Optimum dimensions are different for 13.56 MHz RF and 60 Hz AC power input.
In another exemplary embodiment, illustrated in FIGS. 11-12, a small reactor heating system was constructed to demonstrate the ability of a coaxial heating apparatus (“heating elements”), including, but not limited to, one or more MF heaters, to efficiently heat a fluid in a high pressure reactor. The reactor used free convection to cause fluid flow and to impede settling of solids from the fluid. Any suitable frequency, including, but not limited to RF, may be utilized. In one exemplary embodiment, a frequency of approximately 60 Hz was utilized to heat a fluid in a reactor. FIG. 11 illustrates a high pressure reactor 500, with reactor 502, insulator 504, reactor wall 506, chimney 508, chimney spacers 510, and fittings 512. FIG. 12 illustrates an embodiment with high pressure reactor 600 having reactor 602, chimney 604, insulator 606, electrode 608, and fittings 610.
The reactor comprised of a vertical circular cylindrical chamber with a coaxial cylindrical electrode near the bottom of the chamber. The chamber also contained a coaxial cylindrical tube that surrounded the electrode, which did not go the full height of the chamber. It is like a chimney, in that heated fluid rises upward in it. Its purpose was to provide a passage for the fluid that was heated inside the tube, at the electrode, to rise upward because of its lower density. When the hot fluid got to the top of the tube, it would cool by contact with the cooler chamber wall. The fluid density increased as it cooled, causing it to flow downward between the outer wall of the tube and the inner wall of the chamber, where it would cool even more. In this exemplary embodiment, the free convection flow of the fluid could be observed, though in some embodiments it was not fast enough to prevent settling of solids from some fluids.
In another exemplary embodiment, illustrated in FIGS. 13-14, mechanical stirring was incorporated into a reactor to prevent settling of solids; the stirring could also return previously settled solids into the fluid. This embodiment is similar to the embodiment discussed above, but the chimney is eliminated and high pressure batch reactor 700 has reactor 702, insulator 704, electrode 706, cooling jacket 708, fittings 710 and conductor to power 712. The stirring is caused/augmented by rotating the reactor about 100 degrees so that the “bottom” of the chamber is slightly above the “top”. At that time it is released and allowed to swing like a pendulum, but when it gets to the bottom of its swing, it is stopped by allowing it to collide with a soft material; felt was used in an exemplary embodiment to determine if this would work. If it swung freely like a pendulum, the already-settled and packed solids at the bottom were reluctant to mix into the fluid.
In some embodiments, the rotation of the reactor was limited to angles less than about 100 degrees, because larger rotations caused the fluid to get into the gas sampling lines. While his may not have been harmful, in some embodiments it was found that angles of approximately 100 degrees was all that was necessary to obtain the desired mixing.
In some of the exemplary rotating embodiments, the reactor could hold 40 mL of fluid, while some of the free-convection exemplary embodiments could hold 90 mL of fluid. The reason for the decrease in volume is it that when the chimney was not required, the diameter of the chamber could be made smaller. This is an advantage because the chamber wall can be made thinner to handle the same pressure and the heat-up time can be significantly reduced, which is desirable for studying small reaction times. If larger volumes are required, only one part (the pipe section) needs to be constructed.
Several embodiments incorporate a means for cooling the outer wall of the reactor so that the effects of RF and/or 60 Hz can be determined independently of temperature effects at low temperatures. Alternatively, the outer wall of the reactor can be heated using an electrical band or barrel heater to study thermal heating effects independent of RF and 60 Hz effects at high temperature.
The location of the heating/power area(s) can be controlled by changing the dimensions, configuration and location of the heating/power elements. The fluid temperature may be kept at the desired value by using the measured temperature to control the power level of the electric source using standard commercially-available controllers.
As discussed herein, numerous modifications are possible by inserting conductive and nonconductive materials in the fluid flow to provide mixing of the fluid and to ensure uniform distribution of the fluid from the pipe walls to the center of the pipe. These modifications make it possible to control the heating profile across the cross-section of the pipe.
When the power is applied to the fluid/feedstock, it may cause one or more property changes to the fluid. Such property changes may be physical or chemical. Exemplary property changes include, but are not limited to, temperature, pressure, viscosity, and pH. In applying the above described process to certain fluids, the original fluid may be degraded or otherwise changed such that the output product (i.e., after the electrochemical processes described herein), is different than the original fluid/feedstock. In some embodiments, application of the power resulted not only in raising the temperature and/or pressure of the fluid, but produced products. In most embodiments, the products did not exist in the feedstock/fluid.
Fluids that may be used in various embodiments of the present invention include, but are not limited to, gases, pastes, suspensions, plasmas, slurries, liquids, and any combinations thereof and such fluids may be stationary or moving. Fluids may have any conductivity level and be utilized in various embodiments of the present invention. If a fluid has a low conductivity (or any undesired conductivity level), the conductivity may be adjusted/varied by the introduction of other fluids (or materials) which have other (higher or lower) conductivities. These additional fluids or materials may be referred to as amendments, additives, or catalysts.
In various exemplary embodiments, various fluids/feedstock have been processed using the processes and devices described herein. In some exemplary embodiments, feedstock have included lignite and algae. Lignite powder (500 mesh) was used as the feedstock and the product was thick oily fluid whose hydrocarbon content was greatly increased over the feedstock, making the product suitable for liquid fuels after refining. It was noted that combining a small amount of algae with the lignite increased the product yield by 20 to 30%. Subsequent experiments were conducted using duckweed algae alone. These two feedstocks are representative of feedstocks that could be processed using this invention. Other suitable feedstocks include, but are not limited to, coals, such as brown, lignite, sub-bituminous, bituminous, anthracite, waste coals and pond coal fines, woody crops, herbaceous crops, the seeds of oil crops, residues resulting from the harvesting of agricultural crops and nuisance vegetation such as kudzu. Further feedstocks which are suitable for the herein described processes and devices include, but are not limited to, biomass, such biomass including, but not limited to, renewable sources of energy obtained from living or recently living plants, such as trees, or wood waste, algae, yard clippings, corn (for ethanol), etc.
Useful products of the herein described processes and devices include fuels, sulfur, ash, fuel oil, hydrogen gas, phenolic liquids, sugars, amino acids, and other minerals. In some embodiments, products produced as a result of one or more of the above described processes included one or more of the following: Hydrogen, Hydrocarbons (C1-C6), Alkyl Esters, Triglycerides, Quinolines, Ketones, Sterols, Fatty Acids, high grade coal, and other minerals.
Extensive results have been obtained for processing duckweed algae in both recirculating batch mode and in continuous flow-through mode. Four different product groups were identified: (1) Residue that was soluble in dichloromethane, (2) Water-soluble, (3) Insoluble residue and (4) Gases. The table below is an exemplary list of the products obtained from the duckweed algae feedstock using the above described processes and devices. Each group was subdivided into subgroups. The weight fraction of each of the four major groups is expressed as a percentage of the dry weight of the duckweed, which contains about 70% water. Each of the four product groups is further broken down into subgroups, whose weights are expressed as a percentage of its group.


	Weight
	of Group as	Weight of
	a pecentage	Subgroup as
Product Group/	of Algae	a pecentage of
Subgroup	Dry Weight	Group Weight	Comment

(1) Dichloromethane-	6
Soluble Products
Nonpolars		30-40	Fuel oils
Alkyl Esters		5-20	Glycerin products
Triglycerides		0-5
Quinolines, Ketones,		10-20
Sterols
Fatty Acids		25-45	Convertible to
			Fuels
(2) Water Soluble	28	100	Sugars and amino
Products			acids
(3) Insoluble Residue,	10	100
Char
(4) Gases	47	100
Hydrogen		55.5	High energy
			content fuel
Oxygen		9.8
Nitrogen		24.0
Carbon dioxide		5.5
Carbon monoxide		5.6
Nitric oxide		2.5
Hydrocarbons (C1-C6)		0.3	Fuels
Over counted		−3.2	Analysis error
(5) Unaccounted	9		Analysis error

The products produced in various embodiments contained more hydrogen than was in the original feedstock. The added hydrogen was assumed to be produced by electrolysis at the electrodes, but calculations indicated that more hydrogen was produced than was produced at the electrodes. A bench top apparatus was constructed, which could not operate at high temperatures and pressures, but it allowed a visual observation of the gas bubbles produced by electrochemistry. It consisted of a Lucite plate containing a grooved channel with electrodes at opposite ends. The channel was filled with saltwater and a direct current source was connected to the electrodes. As expected, bubbles occurred at both electrodes, chlorine at one end and hydrogen at the other. No bubbles occurred in the bulk of the saltwater. The saltwater heated because of ohmic heating. Then particles of algae, graphite or copper, i.e., amendments as described herein, were dispersed in the saltwater. In all three cases bubbles appeared throughout the bulk of the saltwater and were greatest where the particles were most dense. The dc current through the cell was maintained at the level it was before adding particles and visually the bubbles at the electrodes were as they were before adding the particles. However, orders of magnitude more bubbles were produced in the bulk of the saltwater. The reason for this is that chlorine and hydrogen ions migrate to opposite ends of the conducting particles and undergo electrochemical reactions on the surfaces of the particles. The particles between the two electrodes at the ends of the channel create many electrochemical cells in series, except in this case, each cell is not in its own closed vessel. Naturally, there is a voltage drop at the interface between the particle surface and the saltwater, just as there is at the electrodes of any electrochemical cell. This voltage drop at the surface of a particle multiplied by the current flowing through the particle is the power required to produce the electrochemical reaction at that particle. The integrated power used in this manner by all the particles causes reduces the ohmic heating of the saltwater; this reduction in heating was not measured in these experiments.
The result of these bench top experiments qualitatively explains the increased hydrogen content of the products of this invention. In many processes where hydrogenation of the feedstock is required, hydrogen gas is added to the process, which increases its cost. In the processes and devices described herein, an external hydrogen source is not needed. In addition, it is known that electrochemically produced hydrogen at an electrode first appears as a hydrogen radical, which is highly reactive, much more than the hydrogen molecule. Since in the processes and devices described herein the electrochemically produced hydrogen radical is at the surface of the particulate feedstock, it is much more effective in reacting with the feedstock than is a hydrogen molecule that would be supplied from a gas bottle.
In some embodiments of the present invention, an applicator is defined as having one or more power sources, one or more electrodes and one or more additional conductive materials. The applicator is thus able to heat the fluid as the power is able to be conducted from the electrode, through the fluid, to the other conductive material(s). Some embodiments may be comprised of a single applicator, whereas other embodiments may have additional applicators. In some embodiments, the applicators may be in series, while in others they may be in parallel. In some embodiments, it may be advantageous to independently monitor and control each applicator, or each power source of each applicator, to more accurately control the temperatures of the fluid. Thus, in some embodiments, the chemical and/or physical reactions taking place in the fluid may be monitored and controlled through manipulation/control of the power and frequencies being applied at that time and location.
Some embodiments may be utilized in various systems including, but not limited to, batch systems, continuous systems, and continuous-batch systems.
The transport vehicles/holding chambers of the present invention may be any suitable vehicle including, but not limited to, pipe/piping, chambers, reactors, reservoirs, open cell, and closed cell.
While the specification has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. Also note that the various components may be of any suitable shape and configuration depending on the desired application for the device. Accordingly, the scope of the present invention should be assessed as that of the described embodiments and any equivalents thereto.

Claims

1. A fluid processing device comprising:

at least one reactor having an interior reactor surface and an exterior reactor surface,

at least one applicator comprising at least one power source and at least one electrode and at least one additional conductive material for direct heating of a feedstock and for producing electrochemical changes in said feedstock,

wherein said direct heating causes at least one property change of said feedstock and at least one product.

2. The device of claim 1, wherein said power source operates at a frequency domain selected from the group consisting of direct current, alternating current, radio frequency, and microwave domains.

3. The device of claim 1, further comprising controls for monitoring or adjusting the power and or frequency of the power source.

4. The device of claim 1, further comprising at least one amendment which is amended to said feedstock to alter the feedstock's electrical conductivity.

5. The device of claim 1, wherein said device is capable of withstanding supercritical temperatures and pressures.

6. The device of claim 1, further comprising at least one amendment which is amended to said feedstock to promote electrochemical reactions in the fluid.

7. The device of claim 1, wherein the feedstock is selected from the group consisting of water, biomass, fossil fuels, seawater, contaminated fluids, slurries, emulsions, pastes, liquids, gases, plasmas, or combinations thereof.

8. An electrochemical processing system consisting of one or more power sources, one or more electrodes and at least one additional conductive material in contact with an electrically conductive fluid to be processed, wherein the fluid is contained within a closed containment vessel for batch processing or in a pipe for continuous flow-through processing, the vessel or pipe being made of materials able to withstand supercritical temperatures and pressures wherein the electric field passes between the electrode and the additional conductive material throughout the fluid to heat the fluid to temperatures as high as supercritical to enhance the reactivity of the process.

9. The electrochemical processing system of claim 8, wherein said power source operates at a frequency domain selected from the group consisting of direct current, alternating current, radio frequency, and microwave domains.

10. The electrochemical processing system of claim 8, wherein said power source is able to rapidly control fluid temperature to optimize chemical reactions and prevent overheating.

11. The electrochemical processing system of claim 8, wherein a frequency of said power source can be adjusted to suit the dynamics of the chemical reactions and optimize yield of desirable products.

12. An electrochemical process for promoting reactions in a fluid by applying an electric field to said fluid that causes direct and uniform heating of said fluid to any desired temperature and pressure, even up to and beyond supercritical domain, as well as causing electrochemical reactions to produce the sought after property changes of said fluid,

wherein the temperature, power, frequency, time and flowrate may be varied.

13. A process for heating a fluid to any desired temperature and pressure up to and beyond supercritical domain by applying an electric field through which the current of the electric field causes direct heating of said fluid to change properties of said fluid.

14. The process of claim 13, wherein the temperature, power, frequency, time and flowrate may be varied.

15. The process of claim 13, wherein said power source operates at a frequency domain selected from the group consisting of direct current, alternating current, radio frequency, and microwave domains.

16. The process of claim 13, wherein said property changes are physical.

17. The process of claim 13, wherein said property changes are chemical.

18. The process of claim 13, wherein said heating utilizes a coaxial system.

19. The process of claim 13, wherein the fluid is selected from the group consisting of water, biomass, fossil fuels, seawater, contaminated fluids, slurries, emulsions, pastes, liquids, gases, plasmas, or combinations thereof.

20. The process of claim 13, wherein one or more amendments are combined with the fluid to provide a conductivity for a combined fluid which is measurably different from the conductivity of the uncombined fluid.

21. The process of claim 13, wherein the heating of the fluid is immediate and spontaneous.

22. An electrochemical process for heating a fluid by applying an electric field through which the current of the electric field causes direct heating of said fluid to change properties of said fluid and said heating causes physical and chemical reactions to take place such that products are produced that did not exist in the fluid prior to heating.

23. The process of claim 22, wherein at least a portion of said fluid contains algae and said byproducts include Hydrogen, Hydrocarbons (C1-C6), Alkyl Esters, Triglycerides, Quinolines, Ketones, Sterols and Fatty Acids.

24. The process of claim 22, wherein at least a portion of said fluid contains at least one member of a group consisting of brown coal, lignite, sub-bituminous, bituminous, and anthracite coal slurries, waste coal and pond coal fines and said products include hydrocarbons, fuels, high grade coal, sulfur, ash, and other minerals.

25. The process of claim 22, wherein at least a portion of said fluid contains at least one member of a group consisting of woody crops, herbaceous crops, the seeds of oil crops.

26. The process of claim 22, wherein at least a portion of said fluid contains at least one member of a group consisting of algae, woody crops, herbaceous crops, the seeds of oil crops and at least one member of a group consisting of brown coal, lignite, sub-bituminous, bituminous, and anthracite coal slurries, waste coal and pond coal fines.