Patent Publication Number: US-2015078827-A1

Title: Induction heating system for thermal desorption processes

Description:
The present application claims priority from U.S. provisional patent application Ser. No. 61/878,620, filed on Sep. 17, 2013, entitled: “Induction heating system for thermal desorption processes” which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The use of petroleum hydrocarbons as a fuel source is ubiquitous in society. Consequently, petroleum hydrocarbon products are stored and handled in great quantities. One risk associated with the storage and handling of petroleum hydrocarbons is the potential for spillages during handling or the potential for leakage during storage. Due to the negative environmental impact associated with spills and leakages of petroleum hydrocarbons, rules have been established at the local, state and federal levels. These rules primarily focus on preventing petroleum hydrocarbon releases to the environment from occurring. These rules also have provisions that require the responsible party to remediate petroleum hydrocarbon releases to the environment. 
     In the field of petroleum hydrocarbon remediation from soil, there are two basic approaches: applying a treatment technique to soil in place (in-situ), or applying a treatment technique to excavated soil (ex-situ). There are advantages and disadvantages for each approach and the selection of the approach is based on the site-specific circumstances of each petroleum hydrocarbon release. 
     Ex-situ thermal desorption technologies can include techniques that involve mechanical agitation of the soil during the heating process, which involve mechanical agitation and operate in a continuous process where the soil is continuously introduced to the process and is mechanically moved through the process apparatus until treatment is complete, and then is continuously discharged to a container for disposal or re-use. 
     Alternately, the soil can be treated in a static configuration, in which a given amount of soil is introduced to the treatment chamber. The soil configurations can include pile arrangement and container arrangements. 
     Nearly all the prior art processes use combustion of fossil fuel as a heat source. This can have the undesirable consequence of forming products of incomplete combustion, oxides of nitrogen, and other greenhouse gases as a by-product. Combustion also has the potential to add unburned hydrocarbons to the process exhaust gas if strict control of the combustion process is not maintained. 
     There can a need for an ex-situ static process that is labor, time and energy efficient in the treatment process, and is environmentally friendly. 
     SUMMARY 
     In some embodiments, the present invention discloses systems and methods for treating contaminate soil using inductive energy. An inductive generator can be coupled to a treatment chamber, and can generate inductive power in the treatment chamber. Inductively heatable elements can be disposed in the contaminate soil or in a soil box, which can be heated by the inductive generator. 
     The inductively heatable elements can include elements fixedly coupled to the soil box, such as steel bars horizontally or vertically welded to the soil box. The inductively heatable elements can be configured to heat the soil uniformly. The inductively heatable elements can include elements disposed in the soil, such as steel balls dispersed in the soil. 
     The inductively heatable elements can be placed in a mesh conduit, which can accept an input treatment gas. The treatment gas can be heated when passing through the inductively heatable elements, and then released to the soil to treat the soil. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A-1B  illustrate schematic evaporative desorption systems according to some embodiments. 
         FIGS. 2A-2B  illustrate induction heating systems for a thermal desorption process according to some embodiments. 
         FIGS. 3A-3E  illustrate soil box configurations having inductive heatable elements according to some embodiments. 
         FIGS. 4A-4B  illustrate flow charts for forming systems to treat contaminate soil according to some embodiments. 
         FIG. 5  illustrates a soil box positioned in a treatment chamber according to some embodiments. 
         FIG. 6  illustrates a flow chart for treating contaminate soil according to some embodiments. 
         FIG. 7  illustrates a soil box positioned in a treatment chamber according to some embodiments. 
         FIGS. 8A-8F  illustrate a sequence of treatment using dispersed inductively heatable elements according to some embodiments. 
         FIG. 9  illustrates a flow chart for processing a contaminate soil according to some embodiments. 
         FIG. 10  illustrates a thermal desorption system using inductive heating according to some embodiments. 
         FIGS. 11A-11C  illustrate connection ports for treatment gas coupling according to some embodiments. 
         FIGS. 12A-12C  illustrate thermal desorption systems using inductive heating according to some embodiments. 
         FIG. 13  illustrates a flow chart for treating contaminate soil according to some embodiments. 
         FIG. 14  illustrates a thermal desorption system using inductive heating according to some embodiments. 
         FIG. 15  illustrates another configuration for an induction heating system according to some embodiments. 
         FIG. 16  illustrates another configuration for an induction heating system according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In some embodiments, the invention relates to a process and apparatus for non-combustive thermal desorption of volatile contaminates from contaminated earth. The earth may include tar sand, oil sand, oil shale, bitumen, pond sediment, and tank bottom sediment. The concentration of the contaminates can be low concentration, e.g., less than about 3%, or high concentration, e.g., greater than about 3%. The process can provide cracking of the contaminates, and/or reclaiming condensable contaminates, then oxidizing and treating the non-condensable reclamation effluent, which can be recycled for use as the thermal desorption treatment gas. 
     The non-combustive thermal desorption of volatile contaminates from low concentration contaminated earth is described in U.S. Pat. No. 6,829,844 (Brady et al) which is incorporated herein by reference in its entirety. The thermal desorption is intended to remove organic contamination from porous media such as soil, rock, clays or other porous media with low organic contamination (less than 3% organic contamination) where desiccated electrically heated atmospheric air is used as the primary treatment gas. High organic contamination (greater than 3%) requires an inert (low oxygen) treatment gas to preclude explosions. 
     In some embodiments, the present invention, an evaporative desorption and/or reclamation process, can be cost effectively constructed to any scale and can exceed the 10 ton per hour production rate of indirect rotary kilns. The method can rely on hot air moving through a static volume of porous media. No mixing mechanisms for the porous media are required for treatment. In addition the process can recycle its heated treatment gas supply, minimizing energy required for treatment. 
     In some embodiments, the invention relates to a process and apparatus for thermal desorption of contaminates from a mixture of soil and rocks using desiccated, non-combustion-heated fresh treatment gas, such as air, to treat the soil and rocks which have been excavated and placed in a thermally conductive treatment container which is then placed in a thermally insulated treatment chamber. The fresh, hot, desiccated air is drawn through the soil treatment container, cooled, and released; or discharged to a treatment system, as required or needed, prior to release to the atmosphere. 
     In some embodiments, a thermal desorption technique applied to a static configuration of contaminated soil using a container arrangement is provided. The thermal desorption technique can restore the soil to its un-contaminated condition by removing the contamination within the soil through the evaporative desorption process. To provide an efficient remediation process, different temperature settings can be used to treat different contaminated soil, and thus sample of the contaminated soil can be tested to determine appropriate treatment conditions. 
     The treatment process for thermal desorption of hydrocarbon contaminants from excavated soil provides efficient contaminant removal by handling the soil in a thermally conductive soil box that is contained in an insulated treatment chamber for treatment. The soil is treated with dry hot air to remove contaminants, and the decontaminated soil can be returned to the ground. 
     In some embodiments, systems and methods to treat contaminated soil are provided, including soil box designs with ease of operation and improved decontamination efficiency and throughput. Simple flow path with minimum turns for the vapor extraction flow paths, such as a large diameter vapor extraction trunk positioned in a middle of the soil box, can provide maximum air flow with minimal head loss. Condensation reduction soil box designs can reduce treatment time, for example, through heating the center of the soil box to reduce condensation within the core of the soil bed or through heating the lower portions of the soil box to reduce temperature stratification. Pedestal connection with self sealing feature can eliminate the need for physical connection of the soil box with the external vapor extraction processing line. 
     In some embodiments, systems and methods are provided to supply thermal desorption of high-concentration hydrocarbon contaminants from excavated soil, such as tar sand, oil sand, oil shale, bitumen, pond sediment, and tank bottom sediment. The systems can provide efficient contaminant removal by handling the soil in a thermally conductive soil box that fits within an insulated treatment chamber. The soil is treated in this chamber with hot dry treatment gas. The contaminates can be reclaimed from the soil box. A portion of the contaminates, such a non-condensable hydrocarbon contaminates, can be used for effluent conditioning, for example, to maintain a desired treatment gas temperature in the soil box. 
     Contaminated earth (soil and rocks or other earthy material) that has been excavated is placed in a thermally conductive soil box which is then placed in a thermally insulated treatment chamber. Heated treatment gases can be introduced to the soil box and flow through the soil box and the contaminated earth. Hot gas extraction, e.g., treatment gases containing contaminates, can be withdrawn from the treatment chamber. The process is continued until the contaminates are completely removed from the soil, e.g., below a desired contamination level. 
     In some embodiments, the contaminates can be reclaimed from the hot gas extraction, for example, through a heat exchanger to cool and separate the condensable contaminates. The remaining hot gas extraction can be treated in a combustion or electrically heated thermal oxidizer, for example, to remove non-condensable contaminates. The output from the thermal oxidizer can be partially recycled to the treatment chamber as the treatment gas, or to maintain the temperature of the treatment chamber. 
     The soil box can have sides to contain the contaminated soil. For example, the soil box can be an open top rectangular cube, prism or cylinder. The soil box can also have a gas exit pathway within the contaminated soil so that gases in the contaminated soil flow to the gas exit pathway. 
     The treatment chamber can have an opening so the soil box may be inserted or removed, a gas inlet to receive hot dry gas, which can be directed to the soil box, and a gas outlet arranged to be mated with the gas exit pathway of the soil box so the gases in the contaminated soil exit the treatment chamber. 
     A heater and drier assembly can be arranged so that the incoming treatment gas to the treatment chamber is dried and heated upon entering the treatment chamber. A blower assembly can be arranged to direct the hot gas extraction from the soil box to exit the treatment chamber. 
     Dry, heated incoming treatment gas can be provided to the soil box, for example, to the opening of the soil box and/or to the sides of the soil box, to transferring heat to the contaminated soil, inducing the migration of contaminates through the soil to the gas exit pathway. The heated treatment gas flows through the contaminated soil, directly heating the soil before entering the gas exit pathway and exiting the chamber, carrying the contaminates. 
       FIGS. 1A-1B  illustrate schematic evaporative desorption systems according to some embodiments. In  FIG. 1A , one or more soil boxes  120  can be placed in a treatment chamber  110 . The treatment chamber can be insulated to prevent heat loss. The soil boxes can be open on top and contain a gas exit pathway  127 . The soil boxes, after filled with contaminated soil  125 , can be installed in the treatment chamber  110  for contamination treatment, and can be removed after the contamination treatment is complete. The soil boxes can provide for a batch process for contaminated soil and clean soil. Hot and dry treatment gas  130  can be introduced to the treatment chamber  110 . The treatment gas can pass through the contaminated soil in the soil box to the gas exit pathway  127  coupled to the treatment chamber exhaust  140 , and then flow out of the treatment chamber  110 . 
     The exhausted treatment gas can contain hydrocarbon contaminates, which can be recovered. A recovering assembly  150  can be coupled to the treatment chamber exhaust  140  to recover all or a portion of the hydrocarbons in the exhaust treatment gas. The recovering assembly  150  can include one or more heat exchangers and a gas extraction fan, which provides the flow of treatment gas from the treatment chamber  110  through the heat exchangers. The contaminates can be condensed and flow to a phase separator to recover the condensate from heat exchangers. Heavy organics, light organics, and water can be separated in the phase separator and flow  160  through the outlets to collection tanks. Remaining residues can be exhausted  170  to a smoke stack. 
       FIG. 1B  shows a soil box positioned in a treatment chamber according to some embodiments. The soil box  121  is a removable, sometimes called a roll-off, hopper modified to contain the gas exit pathway  172 . The open-top soil box  121  can be supported by rollers  122  or steel rails (not shown) in the bottom. The treatment chamber  115  can accept a hot and dry treatment gas  135 , such as desiccated air. The treatment gas can enter the soil  123 , flow  180  toward the gas exit pathway  175 , carrying away the contaminants within the soil. The treatment chamber  115  can be thermal insulated. The soil box  121  contains a gas exit pathway  172  located near the bottom of the soil box. The gas exit pathway can be perforated to allow flow of treatment gas from the surrounding soil into the pathway. The soil box  121  can be installed on a pedestal soil box support that provides a flow path from the soil box gas exit pathway  172  to provide for treatment gas and contaminants from the treatment chamber to exit  145  the chamber. 
     The soil box generally is the thermally conductive vessel used to contain and treat contaminated soil inside the EDU treatment chamber. The soil box can be constructed with vapor extraction lines at the bottom of the soil box. The soil  123  contained within the soil box presents the largest frictional head loss through the entire treatment gas flow path. 
     In some embodiments, the vapor extraction lines can have stainless steel wire wrap well screen to provide the maximum open area for vapor flow. The well screen also can be double wall with thermally resistant filter media such as steel wool or well pack sand. 
     In some embodiments, the vapor extraction lines and vapor flow path can require a simple flow path without unnecessary turns to improve the flow efficiency. The vapor extraction line design can include a large diameter vapor extraction trunk with smaller wire wrap well screens. The small well screens can be double walled with thermally resistant packing material in the annulus. The small screens can offer more open area for vapor flow and eliminate unnecessary turns in the vapor flow path. The center vapor extraction trunk draws all vapors to the center of the soil box. Condensation zones can be reduced or eliminated. 
     One end of the treatment chamber can contain an opening that allows one or more soil boxes to be inserted and removed from the treatment chamber. Soil boxes can be approximately 5 feet high, 5 feet wide, and up to 40 feet long, but may be as small as 8 feet long, in which case the treatment chamber is configured to hold two or more of them. The soil box can be inserted into the housing treatment chamber and removed by rolling or sliding the vessel via forklift or modified loader. Doors can be provided. A gas delivery conduit can be provided at a side of the treatment chamber. A pedestal support can be provided for mating with the soil box. 
     A forklift or modified loader can be used to transport the soil box and the soil contained in it to and from the treatment chamber location. The contaminated soil, once loaded in the soil box at the contamination site, is not removed from the soil box until treatment is complete and it is ready to be returned to a soil disposition site. 
     The treatment chamber can have insulated doors in open or close positions. In the open position the soil box, filled with soil can be easily installed or removed, for example, by a fork lift or a loader. A gas delivery conduit can provide hot dray treatment gas to the chamber. An explosion relief vent provides for venting of the pressurized content of the treatment chamber in the event of rapid pressure increase. The relief vent can direct the expelled gasses upward. The doors can be closed for processing. 
     In some embodiments, the present invention discloses systems and methods to treat contaminated soil, including an induction heating system for more efficient energy consumption. Induction power can be generated from an electromagnetic field, for example, through an inductive coil. Induction power applied directly to the heating recipient components, minimizing heat loss to the surrounding environment. Induction power can be applied directly to the soil box, heating the soil box and the soil inside the soil box. Heat absorbed elements, e.g., inductively heatable elements, such as steel pipe containing iron, can be placed in the soil box for accepting the inductive power. The inductively heatable elements can include conductive materials, in which the eddy current caused by the electromagnetic field can generate thermal energy to heat the materials. High electrical resistance materials can generate higher thermal energy due to the resistance against the eddy current. The inductively heatable elements can include magnetic materials, such as ferrous or ferric materials, in which the magnetic hysteresis loss can generate thermal energy to heat the materials. High relative permeability, higher than 100 or 500, materials can provide higher thermal energy. High relative permeability materials can include iron and iron alloys or compounds such as steel, stainless steel, cobalt, manganese, zinc, and nickel. 
     In some embodiments, induction power can be used to heat the input gas, providing an efficient method to heat the treatment gas. The input gas can be supplied to the heat the soil box, for example, heating the exposed soil surface and the soil box sides. The input gas can be supplied to inner elements, such as pipes located inside the soil box for heating the soil from the inside. The pipes can have openings, for example, along the pipe length or at the ends of the pipes, to release the hot gas to the surrounding soil. In some embodiments, induction power can be used to directly heating the inner pipes that are placed in the soil box. The inductive coils placed at the inner pipes, e.g., surrounding the inner pipes, can heat the input gas at the locations inside the soil box, providing an efficient way of heating the inner soil. 
       FIGS. 2A-2B  illustrate induction heating systems for a thermal desorption process according to some embodiments. In  FIG. 2A , an induction system can be used to heat a treatment chamber. For example, an inductive coil can surround a treatment chamber, to generate an electromagnetic field to heat inductively heatable elements inside the treatment chamber. The inductive coil can run from a sidewall to the top wall to another sidewall to the bottom wall of the treatment chamber. The inductive coil can be configured to leave a front side open for moving a soil box in and out of the treatment chamber. 
     A soil box  220  can be configured to hold contaminated soil, and can be placed in a treatment chamber  210 . The soil box  220  can be configured accept and retain thermal energy from an induction system  230 , for example, including an induction coil  240  to generate electromagnetic field. The soil box  220  can include magnetic materials, such as iron, which can absorb the radiation from the induction system. In addition, magnetic materials, such as rods or balls, can be placed in the soil box, which can also absorb radiation from the induction system. Under the electromagnetic radiation from the induction system, the soil box and/or the magnetic rods can be heated up, which can heat the soil in the soil box to vaporize the volatile contaminants. The vaporized contaminants can be exhausted from the top surface, or from the bottom of the soil. For example, vapor extraction lines  260  can be provided on the floor to extracting volatile contaminants, which can be more efficient than vapor extraction from to top surface. 
     In some embodiments, the soil box can accept an input gas  250 , which can be at room temperature, or can be preheated, for example, by a preheating system using the same induction effect. 
       FIG. 2B  shows another configuration for an induction heating system according to some embodiments. A treatment chamber  215  can be configured to house a soil box  225  for holding the contaminated soil. Vapor extraction lines  265  can be include for extracting vapor contaminants. An input gas  255  can be heated by an induction system  235 , including an inductive coil  245 , for heating the input gas  255  that can be used for heating the contaminated soil. In addition to the induction heating system for heating the input gas, another induction system can be used for heating the soil box, or for heating heatable elements in the soil box. 
     In some embodiments, the inductive heatable elements can include the soil box or addition elements inside the soil box for heating the soil. The inductive heatable elements can be coupled to the soil box, e.g., connected to the soil box, or can be loose, e.g., dispersed within the soil. 
       FIGS. 3A-3E  illustrate soil box configurations having inductive heatable elements according to some embodiments. In  FIG. 3A , an inductive generator  330  can generate electromagnetic field to a soil box  320 . The soil box can include inductive heatable materials, such as conductive materials for eddy current heating, or high permeability materials for hysteresis loss heating. The inductive generator can include a power generator and an inductive coil surrounding the soil box. The soil box can absorb the radiation from the inductive generator to become heated. The heated soil box can heat the contaminate soil in the soil box, desorbing  360  the volatile contaminate. 
     In  FIG. 3B , the soil box  321  and the inductive generator  331  can be placed in a treatment chamber  311 . Alternatively, a portion of the generator  331 , such as the power generator, can be placed outside the treatment chamber, and a inductive coil can be placed around the treatment chamber, either outside or inside. The soil box  321  can include inductive heatable materials, such as conductive materials for eddy current heating, or high permeability materials for hysteresis loss heating. A lid  391 , which can also include inductive heatable materials, can be used for heating the top portion of the soil. An inlet gas  351  can be introduced to the treatment chamber. The inlet gas  351  can be heated outside of the treatment chamber, for example, by an inductive heater system. The inlet gas  351  can be at room temperature, or at any temperature, and can be heated when in contact with the soil, extracting the contaminants to exhaust  361  the soil box and the treatment chamber. 
     In  FIG. 3C , the soil box can include horizontal bars  382 , which can include inductive heatable materials, such as conductive materials for eddy current heating, or high permeability materials for hysteresis loss heating. The soil box  322  can also include inductive heatable materials, or can include other materials. Radiation from an inductive generator  332  can pass to the treatment chamber  312 , heating the horizontal bars  382 , which in turn, can heat the soil to a temperature that can desorb the contaminants. An inlet gas  352  can be introduced to the treatment chamber. The inlet gas  352  can be heated outside of the treatment chamber, for example, by an inductive heater system. The inlet gas  352  can be at room temperature, or at any temperature, and can be heated when in contact with the soil, extracting the contaminants to exhaust  362  the soil box and the treatment chamber. 
     The horizontal bars can be placed at any angle, such as vertical. In addition, elements having different geometry such as tubes, rods, straight or curve can be used. In  FIG. 3D , the soil box can include vertical bars  383 , which can include inductive heatable materials, such as conductive materials for eddy current heating, or high permeability materials for hysteresis loss heating. The soil box  323  can also include inductive heatable materials, or can include other materials. Radiation from an inductive generator  333  can pass to the treatment chamber  313 , heating the vertical bars  383 , which in turn, can heat the soil to a temperature that can desorb the contaminants. An inlet gas  353  can be introduced to the treatment chamber. The inlet gas  353  can be heated outside of the treatment chamber, for example, by an inductive heater system. The inlet gas  353  can be at room temperature, or at any temperature, and can be heated when in contact with the soil, extracting the contaminants to exhaust  363  the soil box and the treatment chamber. 
     Other configurations can be used, in addition to the horizontal or vertical bars. For example, scraps of inductive heatable materials can be dispersed in the soil for heating the soil. In  FIG. 3E , balls  384  can be mixed with the soil in the soil box. The balls can include inductive heatable materials, such as conductive materials for eddy current heating, or high permeability materials for hysteresis loss heating. Other shapes can also be used, such as rod, cylinder, or an irregular shape. The soil box  324  can also include inductive heatable materials, or can include other materials. Radiation from an inductive generator  334  can pass to the treatment chamber  314 , heating the balls  384 , which in turn, can heat the soil to a temperature that can desorb the contaminants. An inlet gas  354  can be introduced to the treatment chamber. The inlet gas  354  can be heated outside of the treatment chamber, for example, by an inductive heater system. The inlet gas  354  can be at room temperature, or at any temperature, and can be heated when in contact with the soil, extracting the contaminants to exhaust  364  the soil box and the treatment chamber. 
       FIGS. 4A-4B  illustrate flow charts for forming systems to treat contaminate soil according to some embodiments. In  FIG. 4A , a soil box can be formed for inductive heating contaminate soil. Operation  400  forms a soil box. The soil box can be configured to support a contaminated soil. Operation  410  couples inductively heatable elements to the soil box. The inductively heatable elements can include materials that can be heated by an induction coil, e.g., by a magnetic field or an electromagnetic field. The inductively heatable elements can include high resistivity materials that can have eddy current that can generate thermal energy. The inductively heatable elements can include high permeability materials that can have high hysteresis loss that can generate thermal energy. The high permeability materials can include materials having relative permeability greater than 100, or greater than 200, or greater than 500, such as iron, iron alloys or compounds such as steel, stainless steel, cobalt, manganese, and nickel. 
     In  FIG. 4B , a treatment chamber can be form for generating inductive energy for heating inductively heatable materials in a soil box. Operation  430  forms a treatment chamber. The treatment chamber can be configured to support a soil box. Operation  440  forms an inductive generator around the treatment chamber. The inductive generator can be operable to heat inductively heatable elements in the soil box. For example, the inductive generator can include a power generator and an inductive coil, which can be configured to surround the treatment chamber, and thus surround the soil box when the soil box is placed in the treatment chamber for treating. The power generator can be placed outside the treatment chamber. The inductive coil can be placed inside or outside the treatment chamber. Operation  450  optionally forms an inductive generator around a inlet conduit for supplying a treatment gas to the treatment chamber. The inductive generator can be operable to heat the treatment gas. The heated treatment gas can be used to heat the contaminate soil, removing the contaminants in the contaminate soil. 
     In some embodiments, the present invention discloses treatment systems and methods for thermal desorption of contaminate soil using inductive energy. A treatment chamber can have an inductive energy generator configured to heat inductively heatable elements in or contacting the contaminate soil. For example, the contaminate soil can be placed in a soil box. The soil box can have inductively heatable elements disposed inside the soil box, for contacting the soil for heating the soil. Heated treatment gas can be introduced to the treatment chamber, passing through the heated contaminate soil, and then exhausting through an exhaust conduit, carrying the contaminants. 
       FIG. 5  illustrates a soil box positioned in a treatment chamber according to some embodiments. The soil box  520  is a container that can be removed from the treatment chamber. The soil box can include inductively heatable elements such as horizontal rods  540 , distributed for efficiently heating the soil  525 . For example, the rods  540  can be disposed in a way to evenly heating the soil. An inductive energy generator  530  can be used to heat the inductively heatable elements, for example, through magnetic field or electromagnetic field generated by the generator  530  and absorbed by the inductively heatable elements. 
     The treatment chamber  510  can accept a treatment gas  555 , such as air. The treatment gas can be heated, for example, by an inductive energy generator  535 . The treatment gas can enter the soil  525 , flow toward the gas exit pathway  570 , carrying away the contaminants within the soil to an exhaust  560 . The soil box  520  contains a gas exit pathway  570  located near the bottom of the soil box. 
       FIG. 6  illustrates a flow chart for treating contaminate soil according to some embodiments. Operation  600  provides a soil box. The soil box is configured to support a contaminated soil. The soil box comprises inductively heatable elements. Operation  610  heats the inductively heatable elements. Operation  620  optionally inductively heats a treatment gas. Operation  630  flows the heated treatment gas through the contaminate soil to decontaminate the contaminated soil. 
     In some embodiments, inductively heatable elements can be dispersed in the contaminate soil to heat the soil through the absorbed inductive energy. The inductively heatable elements can be added to the soil before the treatment, and then removed following the treatment. Since the inductively heatable elements can include high permeability materials such as containing iron, a magnet can be used to remove the inductively heatable elements from the soil. 
       FIG. 7  illustrates a soil box positioned in a treatment chamber according to some embodiments. The soil box  720  can be configured to contain contaminate soil  725 . The soil can include inductively heatable elements such as balls  740 , mixed in the soil for efficiently heating the soil  725 . An inductive energy generator  730  can be used to heat the inductively heatable elements, for example, through magnetic field or electromagnetic field generated by the generator  730  and absorbed by the inductively heatable elements. 
     The treatment chamber  710  can accept a treatment gas  755 , such as air. The treatment gas can be heated, for example, by an inductive energy generator  735 . Inductive heatable elements  736  can be disposed in the treatment gas inlet to be heated by the inductive energy generated from the generator  735 . When passing through the inductive heatable element  736 , the treatment can be heated, for example, by collision with the heated inductive heatable elements  736 . The treatment gas can enter the soil  725 , flow toward a mesh  770 , and carry away the contaminants within the soil to an exhaust  760 . The soil box  720  contains a curve mesh  770  located near the bottom of the soil box to collect the treatment gas to the exhaust. 
       FIGS. 8A-8F  illustrate a sequence of treatment using dispersed inductively heatable elements according to some embodiments. In  FIG. 8A , inductively heatable elements  840 , such as steel balls, can be added to contaminated soil  825 . In  FIG. 8B , the inductively heatable elements  840  can be mixed to evenly disperse the inductively heatable elements  840  in the soil  825 . In  FIG. 8C , the soil  825  and the inductively heatable elements  840  can be placed in a soil box  820 . Alternatively, the soil  825  can be placed in the soil box  820 , and the inductively heatable elements  840  can be added to the soil box. 
     In  FIG. 8D , the soil box is placed in a treatment chamber  810 . An inductive energy generator  830  can heat the inductively heatable elements, which can heat the soil in the soil box. An input gas  855 , which can also be heated by a heater  835 , can pass through the heated soil to carry away the contaminants to the exhaust  860 . In  FIG. 8E , the soil, and the inductively heatable elements  840  can be removed from the soil box. In  FIG. 8F , a magnet can be used to remove the inductively heatable elements  840  from the soil, leaving a clean soil  827 . 
       FIG. 9  illustrates a flow chart for processing a contaminate soil according to some embodiments. Operation  900  mixes inductively heatable elements to a contaminate soil. Operation  910  brings the contaminate soil having the inductively heatable elements to a treatment chamber. The treatment chamber comprises an inductive generator. The inductive generator is operable to heat inductively heatable elements. Operation  920  heats the inductively heatable elements. Operation  930  optionally inductively heats a treatment gas. Operation  940  flows the heated treatment gas through the contaminate soil to decontaminate the contaminated soil. Operation  950  removes the inductively heatable elements from the decontaminated soil. 
     In some embodiments, treatment gas can be heated by induction heating. An inductive generator can generate an electromagnetic field in a treatment chamber. Inductively heatable elements can be disposed in the soil, and the treatment gas can pass through the inductively heatable elements, to be heated, and then passing through the contaminate soil to remove the contaminants. 
       FIG. 10  illustrates a thermal desorption system using inductive heating according to some embodiments. Input treatment gas, such as air or dry air, can flow to a treatment chamber  1010 , for example, through a manifold  1050 , through conduits  1055  to a soil box  1020 . The soil box can include inductively heatable elements  1085 , disposed inside mesh conduits  1080 . The mesh conduits can include screen pipes, such as well screen tubes. The inductively heatable elements can include porous materials disposed in the mesh conduit. The inductively heatable elements can include fiber materials or other small pieces of materials, which can be heated and then transfer the heat to the coming treatment gas. The input treatment gas can pass through the inductively heatable elements  1085 , and through holes in the mesh  1080  to the soil  1025 . An inductive generator  1030  can generate the inductive energy to heat the inductively heatable elements  1085 . Thus the system can be heated from inside of the soil. The treatment gas can extract the contaminants in the soil, and exhaust  1060  through the bottom screen  1070  to the exhaust port. 
     Connection ports  1057  can be used to couple the conduit  1055  to the soil box, e.g., to the mesh conduits  1080  in the soil box. The connection ports  1057  can allow the treatment gas to come from the manifold  1050  to the inside of the soil in the soil box. 
     The connection ports can be movable, e.g., retracting for removing and placing the soil box, and extending for coupling with the soil box after the soil box has been placed in the treatment chamber. Alternatively, automatic seal can be used, in which the connection ports are automatically coupled to the soil box when the soil box is placed in the treatment chamber. 
       FIGS. 11A-11C  illustrate connection ports for treatment gas coupling according to some embodiments. In  FIG. 11A , the connection ports  1157  is in a retracted state  1190 . Thus a soil box  1120  can be taken out or brought in the treatment chamber  1110 . In  FIG. 11B , the connection ports  1157  is in an extended state  1195 , for example, after the soil box  1120  has been placed in the treatment chamber  1110 . After extending, the connection ports can be sealed with the soil box surface, e.g., to deliver treatment gas from the input gas manifold  1150  to the gas conduits  1155  to the inside of the soil in the soil box. The connection ports  1157  can be spring-loaded to allow retracting and extending. Also, the connection ports can be coupled to a mechanism, linking the door of the treatment chamber to the retract/extend mechanism of the connection ports. For example, when the door is open, the mechanism automatically retracts the connection ports, e.g., to allow removal or placing the soil box. When the door is close, the mechanism automatically extends the connection ports, e.g., to allow treatment gas to enter the soil in the soil box. 
       FIG. 11C  shows another configuration for the connection ports. The soil box  1131  can have a slanted sidewall  1132 , with the mesh conduits  1180  and the inductively heatable elements  1185  coupled to the slanted sidewall  1132 . The manifold  1151  can have connection ports  1158  configured to mate with the slanted sidewall of the soil box. 
     In operation, the soil box can be lifted up and brought to the treatment chamber. When dropping down, the sidewall of the soil box can mate with the connection ports  1158 . 
       FIGS. 12A-12C  illustrate thermal desorption systems using inductive heating according to some embodiments. In  FIG. 12A , the mesh conduit  1280  containing inductively heatable elements  1285  can be placed vertically, with connection ports at a bottom of the soil box to be connected to gas manifold. A screen  1270  can be placed at a bottom of the soil box for collecting the exhaust gas. In  FIG. 12B , the exhaust gas can be directly released to the exhaust, e.g., without the screen. In  FIG. 12C , the exhaust gas can be released to the top portion (or to any other portion) of the treatment chamber, instead of to the bottom portion. 
       FIG. 13  illustrates a flow chart for treating contaminate soil according to some embodiments. Operation  1300  provides a soil box, wherein the soil box is configured to support a contaminated soil, wherein the soil box comprises mesh pipes having inductively heatable elements. Operation  1310  heats the inductively heatable elements. Operation  1320  optionally inductively heats a treatment gas. Operation  1330  flows the treatment gas through the mesh pipes, wherein the treatment gas is heated by the inductively heatable elements. Operation  1340  receives exhaust gas from the soil box. 
     In some embodiments, inductively heatable elements can be added to the soil in the soil box to increase heat sources, e.g., components that can absorb inductive energy to turn into thermal energy. 
       FIG. 14  illustrates a thermal desorption system using inductive heating according to some embodiments. Input treatment gas, such as air or dry air, can flow to a treatment chamber  1410 , for example, through a manifold  1450 , through conduits  1455  to a soil box  1420 . The soil box can include inductively heatable elements  1485 , disposed inside mesh conduits  1480 . The input treatment gas can pass through the inductively heatable elements  1485 , and through holes in the mesh  1480  to the soil. The treatment gas can extract the contaminants in the soil, and exhaust  1460  through the bottom screen  1470  to the exhaust port. 
     Connection ports  1457  can be used to couple the conduit  1455  to the soil box, e.g., to the mesh conduits  1480  in the soil box. The connection ports  1457  can allow the treatment gas to come from the manifold  1450  to the inside of the soil in the soil box. 
     Additional treatment gas  1455  can be added, with optional inductively heatable elements  1436  which is heated by inductive generator  1435 . Inductively heatable elements, such as steel balls  1487 , can be added to the soil  1425 . Thus the inductive generator  1430  can heat the soil through the inductively heatable elements  1487 , and can heat the treatment gas through the inductively heatable elements  1485 . 
     Other configurations using inductive energy to treat the contaminate soil can be used.  FIG. 15  illustrates another configuration for an induction heating system according to some embodiments. A treatment chamber  1510  can be configured to house a soil box  1520  for holding the contaminated soil. Vapor extraction lines can be include for extracting vapor contaminants. An induction system  1530  can be used for heating an input gas, which can be delivered to embedded gas delivery elements  1540  in the soil box. The hot gas, heated from the induction system  1530 , can be released to the surrounding soil in the soil box, heating the soil. Further, another optional input gas can be provided to the treatment chamber, for example, for heating the contaminated soil from the outside surfaces, such as from the open end of the soil box, or from the soil box walls. 
       FIG. 16  illustrates another configuration for an induction heating system according to some embodiments. A treatment chamber  1610  can be configured to house a soil box  1620  for holding the contaminated soil. Vapor extraction lines can be include for extracting vapor contaminants. An induction system  1630  can be used for heating gases in an embedded gas delivery element  1640 . The hot gas from the embedded gas delivery element  1640 , which is heated from the induction system  1630 , can be released to the surrounding soil in the soil box, heating the soil. Further, another optional input gas can be provided to the treatment chamber, for example, for heating the contaminated soil from the outside surfaces, such as from the open end of the soil box, or from the soil box walls. The induction system  1630  can also heat other embedded elements, such as radiation absorbed elements, to heat the soil by conduction. The induction system can provide thermal energy, e.g., heating electromagnetic absorbed elements such as iron containing materials, to the soil, either by direct heating the soil by conduction, or by heating input gas which can be released to the soil.