Abstract:
In a method of converting alkanes to their corresponding alcohols, ethers, olefins, and other hydrocarbons, a vessel comprises a hollow, unsegregated interior defined first, second, and third zones. In a first embodiment of the invention oxygen reacts with metal halide in the first zone to provide gaseous halide; halide reacts with the alkane in the second zone to form alkyl halide; and the alkyl halide reacts with metal oxide in the third zone to form a hydrocarbon corresponding to the original alkane. Metal halide from the third zone is transported through the vessel to the first zone and metal oxide from the first zone is recycled to the third zone. A second embodiment of the invention differs from the first embodiment in that metal oxide is transported through the vessel from the first zone to the third zone and metal halide is recycled from the third zone to the first zone. In a third embodiment of the invention the flow of gases through the vessel is reversed to convert the metal oxide back to metal halide and to convert the metal halide back to the metal oxide.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a continuation-in-part application under 37 C.F.R. §1.63 of application Ser. No. 10/369,148 filed Feb. 19, 2003, currently pending; which is a continuation application of application Ser. No. 10/114,579, filed Apr. 2, 2002, now. U.S. Pat. No. 6,525,230; which is a continuation-in-part application of application Ser. No. 09/951,570 filed Sep. 11, 2001, now U.S. Pat. No. 6,462,243, claiming priority based on provisional application Ser. No. 60/284,642 filed Apr. 18, 2001. 
     
    
     
       TECHNICAL FIELD  
         [0002]    This invention relates to zone reactors, and more particularly to zone reactors that are useful in processes for converting alkanes to alcohols, ethers, olefins, and other hydrocarbons.  
         BACKGROUND AND SUMMARY OF THE INVENTION  
         [0003]    U.S. Pat. No. 6,462,243 discloses a method of converting alkanes to their corresponding alcohols and ethers using bromine. The patent comprises four embodiments of the invention therein disclosed each including a reactor wherein bromine reacts with an alkane to form alkyl bromide and hydrogen bromide, a converter wherein the alkyl bromide formed in the reactor reacts with metal oxide to form the corresponding alcohol or ether, and numerous other individual components.  
           [0004]    The present invention comprises zone reactors wherein the several reactions disclosed in the co-pending parent application are carried out in a single vessel. In this manner the overall complexity of the system for converting alkanes to their corresponding alcohols, ethers, olefins, and other hydrocarbons is substantially reduced. In addition, heat generated by reactions occurring in particular zones within the vessel can be utilized to facilitate reactions occurring in other zones.  
           [0005]    Various embodiments of the invention are disclosed. In accordance with a first embodiment the zone reactor comprises a countercurrent system wherein gases flow in a first direction and metal compounds flow in the opposite direction. A second embodiment of the invention comprises a cocurrent arrangement wherein the gases and the metal compounds travel in the same direction. The first and second embodiments of the invention are continuous systems as opposed to the third embodiment of the invention which is a fixed-bed system that is continual in operation. In accordance with the third embodiment the metal compounds remain fixed within the vessel while the gases are directed through the vessel first in one direction and later in the opposite direction.  
           [0006]    In the following Detailed Description the invention is described in conjunction with the conversion of methane to methanol. However, as will be appreciated by those skilled in the art, the invention is equally applicable to the conversion of ethane and the higher alkanes to their corresponding alcohols, ethers, olefins, and other hydrocarbons.  
           [0007]    The following Detailed Description also describes the invention in conjunction with the use of a particular halide, i.e., bromine. However, as will be appreciated by those skilled in the art, the invention is equally applicable to the conversion of alkanes to their corresponding alcohols, ethers, and other hydrocarbons utilizing other halides, including in particular chlorine and iodine.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    A more complete understanding of the present invention may be had by reference to the following Detailed Description when taken in connection with the accompanying Drawings wherein:  
         [0009]    [0009]FIG. 1 is a diagrammatic illustration of a countercurrent zone reactor comprising a first embodiment of the invention;  
         [0010]    [0010]FIG. 1A is an illustration of a variation of the countercurrent zone reactor of FIG. 1;  
         [0011]    [0011]FIG. 2 is a diagrammatic illustration of a cocurrent zone reactor comprising a second embodiment of the invention;  
         [0012]    [0012]FIG. 2A is an illustration of a variation of the cocurrent zone reactor of FIG. 2;  
         [0013]    [0013]FIG. 3 is a diagrammatic illustration of a fixed bed zone reactor comprising a third embodiment of the invention;  
         [0014]    [0014]FIG. 3A is an illustration of a variation of the fixed bed zone reactor of FIG. 3;  
         [0015]    [0015]FIG. 14 is a diagrammatic illustration of a zone reactor comprising a fourth embodiment of the invention;  
         [0016]    [0016]FIG. 4A is a sectional view of an apparatus useful in the practice of the embodiment of the invention shown in FIG. 3;  
         [0017]    [0017]FIG. 4B is an illustration of an early stage in the operation of the apparatus of FIG. 4A;  
         [0018]    [0018]FIG. 4C is an illustration of a later stage in the operation of the apparatus of FIG. 4A;  
         [0019]    [0019]FIG. 4D is an illustration of a still later stage in the operation of the apparatus of FIG. 4A;  
         [0020]    [0020]FIG. 5 is a diagrammatic illustration of the use of the apparatus of FIG. 4A in the conversion of mixtures of alkanes to chemically related products;  
         [0021]    [0021]FIG. 6A is a sectional view diagrammatically illustrating an apparatus useful in practicing a variation of the embodiment of the invention illustrated in FIG. 3;  
         [0022]    [0022]FIG. 6B is a diagrammatic illustration of the utilization of the apparatus of FIG. 6A;  
         [0023]    [0023]FIG. 7 is a diagrammatic illustration of an apparatus useful in the practice of a variation of the embodiment invention shown in FIG. 3;  
         [0024]    [0024]FIG. 8 is a sectional view taken along the line  8 - 8  in FIG. 7 in the direction of the arrows;  
         [0025]    [0025]FIG. 9 is a diagrammatic illustration of a component part of the apparatus of FIG. 7;  
         [0026]    [0026]FIG. 10 is a diagrammatic illustration of an apparatus useful in the implementation of a variation of the embodiment of the invention illustrated in FIG. 3;  
         [0027]    [0027]FIG. 11 is the diagrammatic illustration of an apparatus useful in the practice of a fifth embodiment of the invention;  
         [0028]    [0028]FIG. 12A is an illustration of a first step in the operation of the apparatus of FIG. 11;  
         [0029]    [0029]FIG. 12B is an illustration of a later step in the operation of the apparatus of FIG. 11;  
         [0030]    [0030]FIG. 13A is a diagrammatic illustration of a first step in the operation of an apparatus comprising a variation of the apparatus illustrated in FIG. 11;  
         [0031]    [0031]FIG. 13B is an illustration of a later step in the operation of the apparatus of FIG. 13A;  
         [0032]    [0032]FIG. 15A is a diagrammatic illustration of a first step in the operation of an apparatus comprising a variation of the apparatus illustrated in FIG. 11; and  
         [0033]    [0033]FIG. 15B is an illustration of a later step in the operation of the apparatus of FIG. 15A.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]    The present invention comprises zone reactors wherein three sequential chemical reactions occur in separate zones within a single vessel. In Zone  1  oxygen is reacted with a metal bromide to form bromine gas and the corresponding metal oxide. Bromine gas from Zone  1  passes to Zone  2  where the second chemical reaction occurs. In Zone  2  methane gas is introduced at an intermediate point in the vessel. Methane reacts with the bromine from Zone  1  to form methyl bromide and hydrogen bromide. The latter gasses pass into Zone  3  where the third chemical reaction causes methyl bromide and hydrogen bromide to react with metal oxide to form methanol and metal bromide. Methanol is converted to the liquid phase by condensation and is recovered from the reactor vessel as a liquid. Excess gasses, mostly methane, are separated from the recovered methanol and are returned to the zone reactor along with fresh methane. Metal oxide from Zone  1  is transported to Zone  3  where it proceeds from Zone  3  through Zone  2  to Zone  1  thereby completing the cycle.  
         [0035]    Reactions in Zone  1  are endothermic; therefore, means to supply heat are provided. Zone  2  and Zone  3  involve exothermic reactions; therefore, means to remove heat are provided.  
         [0036]    The separation of zones is not necessarily a sharp one since there is no physical barrier between zones. Therefore, some overlap of reactions may occur. The important element, however, is that all the oxygen is converted to metal oxide in Zone  1  so that little or no oxygen remains to react with methane in Zone  2 . In Zone  2  other bromides, i.e., higher brominated species, in addition to methyl bromide may form and result in products other than methanol in Zone  3 , such as various ethers. Any by-products are separated from methanol in various isolation/purification steps. Any unreacted methane in Zone  2  will pass through Zone  3  and be recycled in Zone  2 . Other unreacted brominated species are returned to Zone  2  either for reaction or to suppress further formation of the higher brominated species by satisfying chemical equilibrium.  
         [0037]    The zone reactor operates at essentially atmospheric pressure and at temperatures up to about 750F. The principal advantage over conventional methanol process lies in the simplicity of the system. The zone reactor achieves the synthesis of methanol in a single vessel whereas the conventional process requires multiple vessels to first produce synthesis gas followed by catalytic reaction. Furthermore the zone reactor operates at slightly above atmospheric pressure whereas the conventional process requires pressures up to 200 atmospheres.  
         [0038]    As will be appreciated by those skilled in the art, the zone reactors of the present invention can be used with ethane and higher alkanes to produce corresponding alcohols, ethers, olefins, and other hydrocarbons.  
         [0039]    The zone reactor also has advantages over a multi-step process utilizing the same bromine chemistry. One advantage is that one step replaces several. In addition, bromine gas remains in one vessel and need not be condensed and re-vaporized.  
         [0040]    [0040]FIG. 1 shows a countercurrent system employing the zone reactor of the present invention. In this embodiment gasses flow upward through a bed of solids which is moving downward. Oxygen is introduced at the bottom of the vessel and reacts with a metal bromide to form bromine gas and the corresponding metal oxide. This step entails regeneration of the metal oxide, which was expended in Zone  3 . Bromine from Zone  1  proceeds to Zone  2  where methane gas is introduced. The methane reacts with the bromine to form methyl bromide and hydrogen bromide. The latter two gasses proceed upward to Zone  3  where fresh metal oxide reacts with these gasses to form methanol and metal bromide. The regenerated metal oxide from Zone  1  is returned to Zone  3  thereby completing the cycle.  
         [0041]    The reaction in Zone  1  may require heat. If so, a suitable heat supply apparatus is provided. In Zone  2  the reactions are exothermic. Heat from the Zone  2  reactor is allowed to raise the temperature of the gasses formed. Zone  3  involves reactions that may require the removal of heat; therefore, a suitable heat removal apparatus is provided.  
         [0042]    The zone reactor of FIG. 1 comprises a unitary vessel. Referring to FIG. 1A, the zone reactor of FIG. 1 may also comprise a vessel having multiple components which are secured one to another by suitable fasteners. This allows removal of components of the vessel for cleaning and/or repair.  
         [0043]    [0043]FIG. 2 shows a cocurrent system employing the zone reactor concept. In this system gasses and solids proceed together in the same direction. In addition the solids are suspended in the gas flow in a way such that the gasses transport the solids. This embodiment combines the reaction steps with the physical movement of the solids. The chemical reaction steps are as described for FIG. 1.  
         [0044]    The zone reactor of FIG. 2 comprises a unitary vessel. Referring to FIG. 2A, the zone reactor of FIG. 2 may also comprise a vessel having multiple components which are secured one to another by suitable fasteners. This allows removal of components of the vessel for cleaning and/or repair.  
         [0045]    [0045]FIG. 3 shows a fixed-bed system comprising a third embodiment of the invention. Whereas FIGS.  1  and  2  describe continuous systems, FIG. 3 describes a continual system. In the system of FIG. 3 the metal bromide/oxide solids remain fixed within the vessel while gasses are passed through the vessel. The regeneration step is carried out in place by reversing the flow of gases through the system. The steps involved and the order in which they are performed are described in FIG. 3. This mode of operation distinguishes itself by avoiding movement of solids as in the embodiments of FIGS. 1 and 2. In addition, by carefully setting the duration of each step the heat generated in Zones  2  and  3  can be at least partially allowed to raise the temperature of the bed. Then, when flow is reversed and Zone  3  becomes Zone  1 , the heat stored in the solids can be used to provide the reaction heat needed in Zone  1 . In this way the overall effect is a direct transfer of heat from the exothermic zone to the zone where it is needed without going through an intermediate step such as steam generation. However, since the heat generated in Zones  2  and  3  is likely to be greater than that needed in Zone  1 , it may still be necessary to remove some heat from the system.  
         [0046]    The zone reactor of FIG. 3 comprises a unitary vessel. Referring to FIG. 3A, the zone reactor of FIG. 3 may also comprise a vessel having multiple components which are secured one to another by suitable fasteners. This allows removal of components of the vessel for cleaning and/or repair.  
         [0047]    Referring to FIG. 14, the zone reactor of the present invention may also comprise separate vessels. Utilization of separate vessels to define the zone reactor allows the use of pumps to control the pressure at which the reaction within each individual vessel takes place. Utilization of separate vessels also allows the use of valves to prevent outflow from a particular vessel until the reaction therein has been completed and to thereafter facilitate transfer of the action products to the next zone.  
         [0048]    The physical separation of the chemical species formed during operation of the zone reactors disclosed herein is accomplished by conventional means, with valuable products and by-products recovered and other useful species returned to the appropriate zone for conversion or satisfaction of chemical equilibrium.  
         [0049]    Referring to FIG. 4A an apparatus  20  is diagrammatically illustrated. The apparatus  20  comprises an imperforate cylinder  22  formed from an appropriate metal, an appropriate polymeric material, or both. The cylinder  22  has closed ends  24  and  26 . A passageway  28  extends through the end  24  of the cylinder  22 , a passageway  30  extends through the end  26  of the cylinder  22 , and a passageway  32  extends to the central portion of the cylinder  22  between the ends  24  and  26  thereof.  
         [0050]    The apparatus  20  further comprises a first zone  34  which is initially filled with metal halide. A second zone  36  located at the opposite end of the cylinder  22  from zone  34  is initially filled with metal oxide. A third or central zone  38  which is centrally disposed between the first zone  34  and the second zone  36  is initially empty.  
         [0051]    Referring to FIG. 4B, a first stage in the operation of the apparatus  20  is shown. Oxygen or air is directed into the first zone  34  through the opening  28 . The oxygen or the oxygen from the air reacts with the metal halide to produce metal oxide and halide. The halide flows from the first zone  34  into the central zone  38 .  
         [0052]    Simultaneously with the introduction of oxygen or air into the first zone  34  through the opening  28 , a selected alkane is directed into the central zone  38  through the opening  32 . Within the central zone  38  halide reacts with alkane to produce alkyl halide and hydrogen halide. The alkyl halide and the hydrogen halide pass from the central zone  38  to the second zone  36 .  
         [0053]    Within the second zone  36  the alkyl halide and the hydrogen halide react with metal oxide to produce products which are recovered through the passageway  30 . The reaction within the second zone  36  also produces metal halide.  
         [0054]    Referring to FIG. 4C, the foregoing reactions in the first zone  34 , the central zone  38 , and the second zone  36  continue until substantially all of the metal halide that was originally in the first zone  34  has been converted to metal oxide. Simultaneously, substantially all of the metal oxide that was originally in the second zone  36  is converted to metal halide. At this point the reaction is stopped and the central zone  38  is evacuated.  
         [0055]    The next stage in the operation of the apparatus  20  is illustrated in FIG. 4D. The reactions described above in conjunction in conjunction with FIG. 4B are now reversed, with oxygen or air being admitted to the second zone  36  through the opening  30 . The oxygen or oxygen from the air reacts with the metal halide in the second zone  36  to produce halide and metal oxide. The halide from the reaction in the second zone  36  passes to the central zone  38  where it reacts with alkane received through the opening  32  to produce alkyl halide and hydrogen halide. Alkyl halide and hydrogen halide from the reaction within the central zone passed to the first zone  34  where they react with the metal oxide contained therein to produce product and metal halide. The reactions continue until substantially all of the metal halide in the second zone has been converted to metal oxide and substantially all of the metal oxide within the first zone  34  has been converted to metal halide at which time the apparatus  20  is returned to the configuration of FIG. 4A. At this point the central zone  38  is evacuated and the above described cycle of operation is repeated.  
         [0056]    Referring to FIG. 5 there is shown an apparatus  40  useful in the practice of the third embodiment of the invention as illustrated in FIG. 3 and described hereinabove in conjunction therewith. Many of the component parts of the apparatus  40  are identical in construction and function to component parts of the apparatus  20  illustrated in FIGS. 4A-4B, inclusive, and described hereinabove in conjunction therewith. Such identical component parts are designated in FIG. 5 with the same reference numerals utilized in the foregoing description of the apparatus  20 .  
         [0057]    The apparatus  40  comprises first and second cylinders  42  and  44 . The cylinders  42  and  44  are each identical in construction and function to the cylinder  22  illustrated in FIGS. 4A-4D, inclusive, and described above in conjunction therewith. The cylinder  42  receives a mixture of alkanes, including methane, ethane, propane, etc., through the opening  32  thereof. The several reactions that occur within the cylinder  42  produce products and methane which are initially recovered through the opening  30 .  
         [0058]    The methane resulting from the reactions which occur within the cylinder  42  is separated from the products resulting from the reactions within the cylinder  42  by conventional techniques such as distillation. The methane is then directed into the cylinder  44  through the opening  32  thereof. Within the cylinder  44  the methane is converted to products utilizing the same reactions described above in conjunction with the apparatus  20 . Products resulting from the reactions occurring within the cylinder  44  are initially recovered through the opening  30  thereof.  
         [0059]    As will be understood by reference to the foregoing description of the operation of the apparatus  20 , operation of the apparatus  40  continues until substantially all of the metal halide that was originally in the first zones  34  of the cylinders  42  and  44  has been converted to metal oxide and until substantially all of the metal oxide that was originally in the second zones  36  of the cylinders  42  and  44  has been converted to metal halide. At this point the direction of flow through the cylinders  42  and  44  is reversed. That is, oxygen is directed into the cylinders  42  and  44  through the passageways  30 , products and methane are recovered from the cylinder  42  through the passageway  28 , and products are recovered from the cylinder  44  through the passageway  28 .  
         [0060]    Referring to FIG. 6A, there is shown an apparatus  50  useful in the practice of a variation of the third embodiment of the invention as illustrated in FIG. 3 and described hereinabove in conjunction therewith. Many of the component parts of the apparatus  50  are substantially identical in construction and function to component parts of the apparatus  20  illustrated in FIGS. 4A-4D, inclusive, and described hereinabove in conjunction therewith. Such substantially identical component parts are designated in FIGS. 6A and 6B with the same reference numerals utilized above in the description of the apparatus  20  but are differentiated there from by means of a prime (′) designation.  
         [0061]    The apparatus  50  differs from the apparatus  20  of FIGS. 4A-4D, inclusive, in that the cylinder  22 ′ of the apparatus  50  includes additional zones  52  and  54  therein. Each of the zones  52  and  54  receives a catalyst the function of which is to facilitate coupling of the alkyl halide molecules produced by the reaction occurring within the central zone  38 ′ thereby producing products comprising higher numbers of carbon atoms than would otherwise be the case. Preferably the catalyst that is contained within the zones  52  and  54  is a selected zeolite. However, the catalyst received within the zones  52  and  54  may also comprise a metal halide/oxide. If a metal halide/oxide is employed within the zones  52  and  54 , it preferably comprises a different metal halide/oxide as compared with the metal halide/oxide that is utilized in the zones  34  and  36 . Operation of the apparatus  50  proceeds identically to the operation of the apparatus  20  as described above except that the presence of a catalyst in the zones  52  and  54  facilitates coupling of the alkyl halide molecules produced within the zone  38  to products.  
         [0062]    Referring now to FIGS. 7, 8, and  9 , there is shown an apparatus  60  useful in the practice of the third embodiment of the invention as illustrated in FIGS.  3  and described hereinabove in conjunction therewith. The construction and operation of the apparatus  60  is similar in many respects to the construction and operation of the apparatus  50  as shown in FIGS. 6A and 6B and described hereinabove in conjunction therewith.  
         [0063]    The apparatus  60  comprises a barrel  62  having a plurality of cylinders  64  mounted therein. The cylinders  64  are imperforate except that each cylinder  64  has a central portion  66  which is perforated. Alkane is received in the barrel  62  through an inlet  68  and passes from the barrel  62  into the cylinders  64  through the perforations comprising the portions  66  thereof. The pressures of the alkane within the barrel  62  is maintained high enough such that alkane flows into the cylinders  64  while preventing the outflow of reaction products therefrom.  
         [0064]    The cylinders  64  of the apparatus  60  are further illustrated in FIG. 9. As indicated above, each cylinder  64  is imperforate except for the perforated portion  66  thereof. The cylinder  64  has end walls  68  and  70  situated at the opposite ends thereof. Each of the end walls  68  and  70  is provided with an oxygen or air receiving passageway  72  and a product discharge passageway  74 .  
         [0065]    Each cylinder  64  comprises a first zone  76  which initially contains metal halide and a second zone  78  which initially contains metal oxide. A third or central zone  80  receives halide through the perforations comprising the perforated portion  66  of the cylinder  64 . Zones  82  located between the zones  76  and  78 , respectively, and the zone  80  contain a catalyst.  
         [0066]    The catalyst contained within the zone  82  preferably comprises a selected zeolite. The catalyst may also comprise a metal halide/oxide. If employed, the metal halide/oxide of the zones  82  is preferably a different metal halide/oxide as compared with the metal halide/oxide comprising the zones  76  and  78 .  
         [0067]    Operation of the apparatus  60  is substantially identical to the operation of the apparatus  50  as illustrated in FIGS. 6A and 6B and described hereinabove in conjunction therewith. Oxygen or air is initially directed into the cylinder  64  through the passageway  72 . The oxygen or the oxygen from the air reacts with the metal halide within the zone  76  to produce halide and metal oxide. The halide passes into the central zone  80  where it reacts with the alkane therein to produce alkyl halide and hydrogen halide. The alkyl halide and hydrogen halide pass through the catalyst within the zone  82  which facilitates coupling of the molecules comprising the alkyl halide into molecules having larger numbers of carbon atoms. The hydrogen halide and the now-coupled alkyl halide next pass into the zone  78  where the hydrogen halide and coupled alkyl halide react with the metal oxide therein to produce product and water. The product and the water are recovered from the cylinder  64  through the outlet  74 .  
         [0068]    The foregoing process continues until substantially all of the metal halide within the zone  76  is converted to metal oxide and substantially all of the metal oxide in the zone  78  is converted to metal halide. At this point the direction of flow through the cylinder  64  is reversed with oxygen or air being received through the opening  72  in the end  70  of the cylinder  64  and products and water being recovered through the opening  74  formed in the end  68  of the cylinder  64 .  
         [0069]    Referring to FIG. 10, there is shown an apparatus  90  useful in the practice of the third embodiment of the invention as illustrated in FIG. 3 and described hereinabove in conjunction therewith. The apparatus  90  comprises the barrel  92  having a heat transfer fluid  94  contained therein. The barrel  92  further comprises a bromination manifold  96  situated at one end thereof and a pair of oxygen receiving/product discharge manifolds  98  and  100  situated at the opposite end thereof.  
         [0070]    A baffle  102  is centrally disposed within the barrel  92 . A plurality of tubular passageways  104  are situated on one side of the baffle  102  and extend between the oxygen receiving/product discharge manifold  98  and the bromination manifold  96 . A plurality of tubular passageways  106  extend between the manifold  96  and the manifold  100 .  
         [0071]    The tubes  104  are initially packed with metal halide. Oxygen or air is received in the manifold  98  through a passageway  108 . The oxygen or the oxygen from the air react with the metal halide within the tubes  104  to produce halide and metal oxide. Halide flows from the tubes  104  into the manifold  96  where it reacts with alkane which is received in the manifold  96  through a passageway  110 .  
         [0072]    The reaction of the halide with the alkane within the manifold  96  produces alkyl halide and hydrogen halide. The tubes  106  are initially filled with metal oxide. The alkyl halide and the hydrogen halide resulting from the reaction within the manifold  96  pass through the tubes  106  thereby converting the metal oxide contained therein to metal halide and producing products. The products are received in the manifold  100  and are recovered there from through a passageway  112 .  
         [0073]    As indicated above, the reaction between the oxygen or the oxygen from the air and the metal halide may be endothermic. Conversely, the reaction of the alkyl halide and the hydrogen halide with the metal oxide may be exothermic. It is also possible that, under certain circumstances, the oxidation of the metal halide is an exothermic reaction and/or that the halide/metal oxide reaction is endothermic. The heat transfer fluid  94  within the barrel  92  flows around the baffle  102  as indicated by the arrows  114  thereby transferring heat between the exothermic reaction and the endothermic reaction and in this manner each achieves thermodynamic equilibrium.  
         [0074]    The reaction of the oxygen or the oxygen from the air with the metal halide within the tubes  104  continues until substantially all of the metal halide has been converted to metal oxide. Similarly, the reaction of the alkyl halide and the hydrogen halide with the metal oxide within the tubes  106  continues until substantially all of the metal oxide has been converted to metal halide. At this point the direction of flow through the apparatus  90  is reversed with oxygen or air being received through the passageway  112  and products being recovered through the passageway  108 .  
         [0075]    Referring to FIGS. 11, 12A, and  12 B, there is shown an apparatus  120  which is useful in the practice in the third embodiment of the invention as illustrated in FIG. 3 and described hereinabove in conjunction therewith. The apparatus  20  includes a bromination chamber  122  which is divided into first and second portions  124  and  126  by a piston  128 . A valve  130  selectively controls the flow of oxygen or air received through a passageway  132  into the portion  124  of the chamber, or directs the flow of products outwardly from the apparatus  120  through a passageway  134 . Oxygen or air entering the apparatus  120  through the passageway  132  and the valve  130  passes through a passageway  136  into a chamber  138  which initially contains metal halide. Within the chamber  138  the oxygen or the oxygen from the air reacts with the metal halide to produce halide and metal oxide. Halide passes from the chamber  138  through a passageway  140  into the portion  124  of the chamber  122 .  
         [0076]    Alkane is received in the portion  124  of the chamber  122  through a passageway  142 , a valve  144 , and a passageway  146 . Within the portion  124  the alkane reacts with halide produced by the reaction within the chamber  138  to produce alkyl halide and hydrogen halide. As the reaction continues the alkyl halide and the hydrogen halide force the piston  128  to move rightwardly (FIG. 11). This process continues until all of the metal halide within the chamber  138  has been converted to metal oxide and the piston  128  has been forced to the extreme right hand end (FIG. 11) of the chamber  122 .  
         [0077]    At the beginning of the procedure just described the portion  126  of the chamber  122  was filled with alkyl halide and hydrogen halide. As will be appreciated by those skilled in the art, the presence of alkyl halide and hydrogen halide in the portion  126  resulted from a flow of oxygen or air through a passageway  148 , a valve  150 , and a passageway  152  into a chamber  154  which was initially filled with metal halide. Reaction of the oxygen or the oxygen from the air with the metal halide produced halide and metal oxide. The halide flowed through a passageway  156  into the portion  126  of the chamber  122  where the halide reacted with alkane received through the passageway  142 , and valve  158 , and a passageway  160 . Within the portion  126  of the chamber  122  the halide reacted with the alkane to produce alkyl halide and hydrogen halide. The production of alkyl halide and hydrogen halide within the portion  126  of the chamber  122  continued until substantially the entire content of the chamber  154  was converted from metal halide to metal oxide.  
         [0078]    Referring particularly to FIG. 12A, rightward movement of the piston  128  forces the alkyl halide and the hydrogen halide outwardly from the portion  126  of the chamber  122  through the passageway  156  into the chamber  154 . At this point the chamber  154  is filled with metal oxide. The alkyl halide and the hydrogen halide from the portion  126  of the chamber  122  react with the metal oxide in the chamber  154  to produce product and water. The product and water pass through the passageway  152 , the valve  150 , and a passageway  162  and are recovered.  
         [0079]    When the piston  128  has reached the right hand end of the chamber  122 , substantially all of the alkyl halide and hydrogen halide have been forced out of the portion  126  of the chamber  122  and have been converted to product by reaction with metal oxide within the chamber  154 . At this point substantially all of the metal oxide within the chamber  154  has been converted back to metal halide. The positioning of the valve  150  is reversed thereby admitting oxygen or air into the chamber  154  through the passageway  148 , the valve  150 , and the passageway  152 . Meanwhile, the positioning of the valve  130  is likewise reversed thereby facilitating the recovery of product resulting from the reaction of the alkyl halide and the hydrogen halide within the portion  124  of the chamber  122  with the metal oxide within the chamber  138 . Thus, the process is continuous with the piston  128  moving back and forth within the chamber  122  to force previously produced alkyl halide and hydrogen halide outwardly through the metal oxide contained in the associated chamber  138  or  154  to produce product.  
         [0080]    Referring to FIGS. 13A and 13B, there is shown an apparatus  170 . All of the component parts of the apparatus  170  are identical to components of the apparatus  120  as illustrated in FIGS. 11, 12A, and  12 B and described hereinabove in conjunction therewith. Such duplicate component parts are identified in FIGS. 13A and 13B with the same reference numerals utilized above in the description of the apparatus  120 .  
         [0081]    The apparatus  170  employs duplicate chambers  138  and  154  along with duplicate components controlling the flow of materials to and from the chambers  138  and  154 . The use of duplicate chambers  138  and  154  and duplicate components ancillary thereto is useful in increasing the throughput rate of the apparatus  170  as compared with that of the apparatus  120  and/or in balancing the kinetics of the reactions occurring within the chambers  138  and  154 .  
         [0082]    Referring to FIGS. 15A and 15B, there is shown an apparatus  172 . All of the component parts of the apparatus  172  are identical to components of the apparatus  120  as illustrated in FIGS. 11, 12A, and  12 B and described hereinabove in conjunction therewith. Such duplicate component parts are identified in FIGS. 15A and 15B with the same reference numerals utilized above in the description of the apparatus  120 .  
         [0083]    The apparatus  172  employs duplicate chambers  122  along with duplicate components controlling the flow of materials to and from the chambers  122 . The use of duplicate chambers  122  and duplicate components ancillary thereto is useful in increasing the throughput rate of the apparatus  170  as compared with that of the apparatus  120  and/or in balancing the kinetics of the reactions occurring within the chambers  122 .  
         [0084]    Although preferred embodiments of the invention have been illustrated in the accompanying Drawing and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention.