Abstract:
Methods and apparatuses are provided for pyrolysis using a falling bed reactor. The falling bed reactor may result in effective mixing between a heat carrier and biomass, and may reduce or eliminate inert gas requirements.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. Provisional Patent Application No. 61/826,989, filed on May 23, 2013, which is incorporated by reference herein in its entirety. 
     
    
     BACKGROUND 
       [0002]    Biomass pyrolysis is conventionally conducted using bubbling fluid beds, circulating fluid bed transport reactors, rotating cone reactors, ablative reactors or auger reactors. Fluidized bed designs such as bubbling fluid bed reactors and circulating fluid bed reactors may provide high heat transfer rates to the substrate, e.g., biomass, and these high heat transfer rates may result in high yield of bio-oil. A disadvantage of fluidized bed systems is that a significant flow rate of inert gas may be needed, which may lead to undesirable parasitic losses. Other designs, such as rotating cone reactors and auger reactors may not require significant inert gas flow, but mixing between the heat carrier and biomass may not be as effective as with fluidized beds, which may lead to lower reaction yields, of bio-oil from bio-mass pyrolysis. The present application appreciates that biomass pyrolysis may be a challenging endeavor. 
       SUMMARY 
       [0003]    In one embodiment, a falling bed reactor is provided. The falling bed reactor may include a reactor conduit defining a flow axis. The falling bed reactor may include an inlet operatively coupled to receive a heat carrier particulate into the reactor conduit. The falling bed reactor may also include an outlet operatively coupled to direct the heat carrier particulate out of the reactor conduit. The falling bed reactor may also include one or more baffles mounted in the reactor conduit, e.g., a plurality of baffles. 
         [0004]    In another embodiment, a falling bed reactor is provided. The falling bed reactor may include a reactor conduit defining a flow axis. The falling bed reactor may include an inlet operatively coupled to receive a heat carrier particulate into the reactor conduit. The falling bed reactor may also include an outlet operatively coupled to direct the heat carrier particulate out of the reactor conduit. The falling bed reactor may further include a pyrolysis substrate inlet operatively coupled to receive a pyrolysis substrate into the reactor conduit. The falling bed reactor may include a pyrolysis product outlet operatively coupled to direct a pyrolysis product out of the reactor conduit. The falling bed reactor may also include one or more baffles mounted in the reactor conduit, e.g., a plurality of baffles. Each baffle in the one or more baffles may include a baffle surface. At least a portion of each baffle surface may be at an oblique angle with respect to the flow axis. 
         [0005]    In one embodiment, a pyrolysis system is provided. The pyrolysis system may include a falling bed reactor and a cross-flow classifier. The falling bed reactor may include a reactor conduit defining a flow axis. The falling bed reactor may include an inlet operatively coupled to receive a heat carrier particulate into the reactor conduit. The falling bed reactor may also include an outlet operatively coupled to direct the heat carrier particulate out of the reactor conduit. The falling bed reactor may further include a pyrolysis substrate inlet operatively coupled to receive a pyrolysis substrate into the reactor conduit. The falling bed reactor may include a pyrolysis product outlet operatively coupled to direct a pyrolysis product out of the reactor conduit. The falling bed reactor may also include one or more baffles mounted in the reactor conduit. Each baffle in the one or more baffles may include a baffle surface. At least a portion of each baffle surface may be at an oblique angle with respect to the flow axis. 
         [0006]    The cross-flow classifier may include a separator conduit. The cross-flow classifier may also include a flow input and a flow output in fluidic communication with the separator conduit. The separator conduit may extend between the flow input and the flow output to define a flow axis along at least a portion of the separator conduit. The flow input may be located upstream of the flow output with respect to the flow axis. The cross-flow classifier may include a cross-flow input and a cross-flow output in fluidic communication with the separator conduit between the flow input and the flow output. The cross-flow input may be located upstream of the cross-flow output with respect to the flow axis. The cross-flow input may define a cross-flow axis intersecting the flow axis at a cross-flow angle between about 70° and about 180° with respect to the flow axis. Further with respect to the pyrolysis system, the outlet of the falling bed reactor may be operatively coupled to the flow input of the cross-flow classifier. Also, the flow output of the cross-flow classifier may be operatively coupled to the inlet of the failing bed reactor. 
         [0007]    In one embodiment, a pyrolysis method is provided. The pyrolysis method may include feeding a heat carrier to a gravity-fed baffled conduit. The pyrolysis method may include feeding a pyrolysis substrate to the gravity-fed baffled conduit such that the heat carrier and the pyrolysis substrate mix to form a pyrolysis mixture. The pyrolysis method may include heating the heat carrier and/or the gravity-fed baffled conduit to pyrolyze the pyrolysis substrate in the pyrolysis mixture to form a pyrolysis product mixture. The “gravity-fed baffled conduit” may include, for example, the falling bed reactor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The accompanying figures, which are incorporated in and constitute a part of the specification, illustrate example methods and apparatuses, and are used merely to illustrate example embodiments. 
           [0009]      FIG. 1  depicts an example falling bed reactor; 
           [0010]      FIG. 2  depicts an example pyrolysis system that includes an example falling bed reactor and an example cross-flow particle classifier; 
           [0011]      FIG. 3  is a block diagram of an example cross-flow particle classifier; and 
           [0012]      FIG. 4  is a flow diagram of an example method for pyrolysis. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIG. 1  depicts an example falling bed reactor  100 . Falling bed reactor  100  may include a reactor conduit  102  defining a flow axis  104 . Flow axis  104  may have a downstream end, indicated by the arrowhead, and an upstream end, indicated by the shaft end of the arrow. Falling bed reactor  100  may include an inlet  106  operatively coupled to receive a heat carrier particulate into reactor conduit  102 . Falling bed reactor  100  may also include an outlet  108  operatively coupled to direct the heat carrier particulate out of reactor conduit  102 . Falling bed reactor  100  may further include a pyrolysis substrate inlet  110  operatively coupled to receive a pyrolysis substrate into reactor conduit  102 . Falling bed reactor  100  may include a pyrolysis product outlet  112  operatively coupled to direct a pyrolysis product out of reactor conduit  102 . Falling bed reactor  100  may also include one or more baffles  114 , e.g.; a plurality of baffles, mounted in reactor conduit  102 . Each baffle in one or more baffles  114  may include a baffle surface  116 . At least a portion of each baffle surface  116  may be at an oblique angle  118  with respect to flow axis  104 . 
         [0014]    As used herein, the “heat carrier” may be a particulate including one or more of: a metal, a glass, a ceramic, a mineral, or a polymeric composite. For example, the heat carrier may be sand. The heat carrier may include a particulate catalyst. For example, the heat carrier may include a fluid catalytic cracking (FCC) catalyst. The heat carrier may include a spent particulate catalyst. For example, the heat carrier may include a spent FCC catalyst. The heat carrier may be in the form of metal shot, for example, steel shot. In various embodiments, the heat carrier, when employed with the cross flow particle classifier, is of a density effective to provide separation between the heat carrier and the char to be separated in the cross flow particle classifier. 
         [0015]    As used herein, an “oblique angle” is any angle that is not an integer multiple of a right angle. For example, an oblique angle excludes 0°, 90°, and 180°, but includes angles between 0° and 90°, and angles between 90° and 180°. 
         [0016]    In various embodiments, falling bed reactor  100  may be configured to be mounted such that at least a portion of flow axis  104  is parallel or oblique to a vertically downward direction. Failing bed reactor  100  may be configured to be mounted such that at least a portion of each baffle surface  116  is at an oblique angle  118  with respect to the vertically downward direction. Failing bed reactor  100  may be mounted to orient flow axis  104  in a substantially vertically downward direction. In this manner, falling bed reactor  100  may be gravity-fed or gravity operated, at Feast in part. For example, the pyrolysis substrate may enter falling bed reactor  100  at pyrolysis substrate inlet  110 , and the heat carrier particulate may enter falling bed reactor  100  at inlet  106 . The pyrolysis substrate and the heat carrier particulate may fall through falling bed reactor  100 , and may be intermittently diverted from flow axis  104  by one or more baffles  114 , for example, as indicated by a path  105 . 
         [0017]    In some embodiments, a cross section of reactor conduit  102  may include a shape that may be one of: polygonal, rounded polygonal, circular, elliptical, or a combination or composite thereof. A cross section of reactor conduit  102  may include a shape that may be one of: rectangular, rounded rectangular, circular, elliptical, or a combination or composite thereof. For example, reactor conduit  102  may be square in cross section. 
         [0018]    In several embodiments, one or both of inlet  106  and outlet  108  may be substantially parallel with one or both of reactor conduit  102  and flow axis  104 . Inlet  106  may be operatively coupled to reactor conduit  102  upstream of outlet  108  with respect to flow axis  104 . 
         [0019]    In some embodiments, falling bed reactor  100  may include a pyrolysis substrate inlet  110  operatively coupled to receive a pyrolysis substrate into reactor conduit  102 . Falling bed reactor  100  may include a pyrolysis product outlet  112  operatively coupled to direct a pyrolysis product out of reactor conduit  102 . 
         [0020]    Pyrolysis substrate inlet  110  may be operatively coupled to reactor conduit  102  upstream of pyrolysis product outlet  112  with respect to flow axis  104 . Pyrolysis substrate inlet  110  may be operatively coupled to reactor conduit  102  upstream of pyrolysis product outlet  112  with respect to flow axis  104 . Pyrolysis substrate inlet  110  may be operatively coupled to reactor conduit  102  at a same level or downstream of pyrolysis product outlet  112  with respect to flow axis  104 . Pyrolysis substrate inlet  110  may be coincident with inlet  106 . Pyrolysis product outlet  112  may be coincident with inlet  106  or outlet  108 . 
         [0021]    In various embodiments, the one or more baffles  114  may extend from an inside wall  130  of the reactor conduit  102  into the reactor conduit  102 . For example, the one or more baffles  114  may extend from the inside wall  130  to define a cantilevered geometry in the reactor conduit  102 . The one or more baffles  114  may extend across at least a portion of the reactor conduit  102  between a first portion of the inside wall  130  and a second portion of the inside wall  130 . Each of the one or more baffles  114  may include a form of one or more of a rod, a plate, a screen, or a protrusion. Each of the one or more baffles  114  may include a form of a rod. The rod may include a cross-sectional geometry that is at least in part polygonal, rounded polygonal, circular, elliptical, or a combination or composite thereof. 
         [0022]    In some embodiments, each of the one or more baffles  114  may include a baffle surface  116 . The baffle surface  116  may be positioned to intersect at least a portion of the reactor conduit  102  with respect to the flow axis  104 . At least a portion of the baffle surface  116  may include a geometry that is one or more of flat or convex. At least a portion of the baffle surface  116  may be horizontal with respect to the flow axis  104 . At least a portion of the baffle surface  116  may be at an oblique angle  118  with respect to the flow axis  104 . 
         [0023]    In various embodiments, one or more baffles  114  may be mounted to place at least the portion of each baffle surface  116  at oblique angle  118  with respect to flow axis  104  such that one or more baffles  114  may form a staggered or alternating pattern in reactor conduit  102 . Each baffle in one or more baffles  114  may be mounted to an inside wall  130  of reactor conduit  102  to define a free edge  120  of each baffle surface  116  and a mounted edge  122  of each baffle surface. In some embodiments, one or more baffles  114  may be configured as an alternating sequence of funnels and cones, the funnels aligned with the flow axis  104  and the cones aligned antiparallel to the flow axis  104 , each of the funnels and cones may include a free edge  120  at a downstream extremity of each of the funnels and cones. In some embodiments, the staggered or alternating pattern of one or more baffles  114  intersecting flow axis  104  to provide a tortuous flow path through one or more baffles  114 . Each baffle surface  11  in one or more baffles  114  may be substantially at oblique angle  118  with respect to flow axis  104 . For example, oblique angle  118  may be between about 30° and about 60° with respect to flow axis  104  such that for each baffle surface  116 , a flee edge  120  of baffle surface  116  may be further downstream along flow axis  104  compared to a mounted edge  122  of baffle surface  116 . 
         [0024]    In several embodiments, falling bed reactor  100  may include an agitator mechanism  126  configured to agitate at least a portion of one or more baffles  114  effective to dislodge a particulate on at least a portion of one or more baffles  114 . Falling bed reactor  100  may include a heater  128 . Heater  128  may be configured cause pyrolysis of a substrate in falling bed reactor  100  by heating one or both of falling bed reactor  100  and a heat carrier to be fed into falling bed reactor  100 . 
         [0025]      FIG. 2  depicts an example pyrolysis system  200 . Pyrolysis system  200  may include falling bed reactor  100  and a cross-flow classifier  3100 . Falling bed reactor  100  may include a reactor conduit  102  defining flow axis  104 . Flow axis  104  may have a downstream end, indicated by the arrowhead, and an upstream end, indicated by the shaft end of the arrow. Falling bed reactor  100  may include an inlet  106  operatively coupled to receive a heat carrier particulate into reactor conduit  102 . Falling bed reactor  100  may also include an outlet  108  operatively coupled to direct the heat carrier particulate out of reactor conduit  102 . Falling bed reactor  100  may further include a pyrolysis substrate inlet  110  operatively coupled to receive a pyrolysis substrate into reactor conduit  102 . Falling bed reactor  100  may include a pyrolysis product outlet  112  operatively coupled to direct a pyrolysis product out of reactor conduit  102 . Falling bed reactor  100  may also include one or more baffles  114  mounted in reactor conduit  102 . Each baffle in one or more baffles  114  may include a baffle surface  116 . At least a portion of each baffle surface  116  may be at an oblique angle  118  with respect to flow axis  104 . 
         [0026]    Cross-flow classifier  3100  may include a separator conduit  3102 . Cross-flow classifier  3100  may also include a flow input  3104  and a flow output  3106  in fluidic communication with separator conduit  3102 . Separator conduit  3102  may extend between flow input  3104  and flow output  3106  to define a flow axis  3108  along least a portion of separator conduit  3102 . Flow input  3104  may be located upstream of flow output  3106  with respect to flow axis  3108 . Cross-flow classifier  3100  may include a cross-flow input  3114  and a cross-flow output  3116  in fluidic communication with separator conduit  3102  between flow input  3104  and flow output  3106 . Cross-flow input  3114  may be located upstream of cross-flow output  3116  with respect to flow axis  3108 . Cross-flow input  3114  may define a cross-flow axis  3118  intersecting flow axis  3108  at a cross-flow angle  3120  between about 70° and about 180° with respect to flow axis  3108 . Further with respect to pyrolysis system  200 , outlet  108  of falling bed reactor  100  may be operatively coupled to flow input  3104  of cross-flow classifier  3100 . Also, flow output  3106  of cross-flow classifier  3100  may be operatively coupled to inlet  106  of filling bed reactor  100 . 
         [0027]    In various embodiments, outlet  108  of falling bed reactor  100  may be operatively coupled to flow input  3104  of cross-flow classifier  3100  via an auger or conveyor  230 . Flow output  3106  of cross-flow classifier  3100  may be operatively coupled to inlet  106  of falling bed reactor  100  via an auger or conveyor  232 . 
         [0028]    In some embodiments, pyrolysis system  200  may include a fine particulate separator  202 . An input  204  of fine particulate separator  202  may be operatively coupled to pyrolysis product outlet  112  of falling bed reactor  100 . Fine particulate separator  202  may include a particulate outlet  206  and a gas or vapor outlet  208 . For example, fine particulate separator  202  may include one or more of: a settling chamber, a baffle chamber, a cyclonic particle separator, an electrostatic precipitator, a filter, or a scrubber 
         [0029]    In several embodiments, pyrolysis system  200  may include a coarse particulate separator  212 . An input  214  of coarse particulate separator  212  may be operatively coupled to cross-flow output  3116  of cross-flow classifier  3100 . Coarse particulate separator  212  may include a particulate outlet  216  and a gas outlet  218 . For example, coarse particulate separator  212  may include one or more of: a settling chamber, a baffle chamber, a cyclonic particle separator, an electrostatic precipitator, a filter, or a scrubber 
         [0030]    In various embodiments, pyrolysis system  200  may include a gas recycle conduit  220 . Gas recycle conduit  220  may be operatively coupled to receive recycled gas from gas outlet  218 . Gas recycle conduit  220  may be operatively coupled to direct the recycled gas to cross-flow input  3114  of cross-flow classifier  3100 . In some embodiments, gas recycle conduit  220  may include a fan  222 . Fan  222  may be configured to draw the recycled gas from gas outlet  218  via gas recycle conduit  220 . Fan  222  may be configured to flow the recycled gas to cross-flow input  3114  of cross-flow classifier  3100  via gas recycle conduit  220 . 
         [0031]    In further embodiments, falling bed reactor  100  in pyrolysis system  200  may include any aspect of falling bed reactor  100  described herein. 
         [0032]      FIGS. 3A and 3B  depict aspects of cross-flow classifier  3100  that may be used in example pyrolysis system  200 . For example, in various embodiments, one or both of flow input  3114  and flow output  3116  may be substantially aligned with flow axis  3108  of separator conduit  3102 . In some embodiments, cross-flow input  3114  may be operatively coupled to separator conduit  3102  substantially opposite to cross-flow output  3116  with respect to flow axis  3108 . 
         [0033]    In some embodiments, cross-flow classifier  3100  may be mounted such that flow axis  3108  points downward at a flow angle  3110 . For example, flow angle  3110  may be less than 90° from vertically downward. In some embodiments, flow angle  3110  may be less than 60° from vertically downward. 
         [0034]    As used herein, “downward” means any direction represented by a vector having a non-zero component parallel with respect to a local gravitational acceleration direction. As used herein, “upward” means any direction represented by a vector having a non-zero component antiparallel with respect to the local gravitational acceleration direction. As used herein, “vertical” means parallel or antiparallel with respect to the local gravitational acceleration direction. “Vertically downward” means parallel with respect to the local gravitational acceleration direction, indicated in  FIG. 1  by arrow  3101 . “Vertically upward” means antiparallel with respect to the local gravitational acceleration direction. As used herein, “horizontal” means perpendicular to the local gravitational acceleration direction. 
         [0035]    In several embodiments, separator conduit  3102  may include a first flow diameter  3122  between flow input  3104  and cross-flow input  3114 . Separator conduit  3102  may include a second flow diameter  3124  downstream of cross-flow input  3114 . First flow diameter  3122  may be greater than second flow diameter  3124 . Separator conduit  3102  may include a transition  3126  between first flow diameter  3122  and second flow diameter  3124 . Transition  3126  may be substantially aligned with cross-flow angle  3120 . For example, transition  3126  may be substantially perpendicular with respect to flow axis  3108 . 
         [0036]    In various embodiments, flow input  3104  may be configured to accept a plurality of particulates. At least a first particulate in the plurality of particulates may be characterized by a first average density. At least a second particulate in the plurality of particulates may be characterized by a second average density greater than the first average density. Flow output  3106  may be configured to convey at least a portion of the first particulate characterized by the first density out of separator conduit  3102 . Cross-flow output  3116  may be configured to convey at least a portion of the second particulate characterized by the second density greater than the first density out of separator conduit  3102 . 
         [0037]    As used herein, a “particulate” refers to a plurality, collection, or distribution of individual particles. The individual particles in the particulate may have in common one or more characteristics, such as size, density, material composition, heat capacity, particle morphology, and the like. The characteristics of the particles in the particulate may be the same among the particles, or may be characterized by a distribution. For example, particles in a particulate may all be made of the same composition, e.g., a ceramic, a metal, or the like. In another example, particles in a particulate may be characterized by a distribution of particle sizes, for example, a Gaussian distribution. 
         [0038]    In some embodiments, cross-flow input  3114  may define a first convergent nozzle  3132 . First convergent nozzle  3132  may include a first nozzle throat  3134 . A cross section of first nozzle throat  3134  may include at least two dissimilar axes. For example, first nozzle throat  3134  may include an elliptical cross section, a circular cross section, a rectangular cross section, a rounded corner rectangular cross section, a polygonal cross section, a composite or combination thereof, or the like. 
         [0039]    In several embodiments, the first nozzle throat  3134  may be operatively coupled to a nozzle exit zone. At least a portion of the nozzle exit zone may include a transition  3126  between a first flow diameter  3122  of flow conduit  3108  and first nozzle throat  3134 . In some embodiments, at least a portion of the nozzle exit zone may include a second flow diameter  3124  of separator conduit  3108 . Transition  3126  may be located at an upstream side of first nozzle throat  3134 . Second flow diameter  3124  may be located at a downstream side of first nozzle throat  3134 . First nozzle throat  3134  may be located at second flow diameter  3124  of separator conduit  3108 . 
         [0040]    In various embodiments, convergent nozzle  3132  of cross-flow input  3114  may include a second nozzle throat  3138 . First nozzle throat  3134  may be located at cross-flow input  3114  between second nozzle throat  3138  and separator conduit  3108 . Cross-flow output  3116  may define a second convergent nozzle  3142 . 
         [0041]    In some embodiments, second convergent nozzle  3142  may include a third nozzle throat  3144 . A cross section of third nozzle throat  3144  may include at least two dissimilar axes. For example, third nozzle throat  3144  may include an elliptical cross section, a circular cross section, a rectangular cross section, a rounded corner rectangular cross section, a polygonal cross section, a composite or combination thereof, or the like. Third nozzle throat  3144  may be operatively coupled to a nozzle entrance zone  3146 . At least a portion of nozzle entrance zone  3146  may include a transition  3148  between a second flow diameter  3124  of flow conduit  3108  and third nozzle throat  3144 . In some embodiments, at least a portion of nozzle entrance zone  3146  may include an entrance vane  3150 . Entrance vane  3150  may extend into separator conduit  3102 , for example, with respect to second flow diameter  3124 . At least a portion of entrance vane  3150  may extend into separator conduit  3102  at least partly in an upstream direction with respect to flow axis  3108 . 
         [0042]    In several embodiments, third nozzle throat  3144  may be operatively coupled through a nozzle collector zone to an exit conduit  3154 . One or both of the nozzle collector zone and conduit  3154  may include an elliptical cross section. For example, one or both of the nozzle collector zone and exit conduit  3154  may include a circular cross section. Third nozzle throat  3144  may be operatively coupled to an exit conduit  3154 . Exit conduit  3154  may define an exit conduit axis  3156 . Exit conduit axis  3156  may intersect flow axis  3108  at an exit angle  3158 . Exit angle  3158  may be greater than 0′ and less than 180°. For example, exit angle  3158  may be between about 90° and less than 180°. In some embodiments, exit conduit axis  3156  may be within about 30° of vertical. 
         [0043]      FIG. 4  is a flow diagram describing an example pyrolysis method  400 . Pyrolysis method  400  may include feeding a heat carrier to a gravity-fed baffled conduit (step  402 ). Pyrolysis method  400  may include feeding a pyrolysis substrate to the gravity-fed baffled conduit such that the heat carrier and the pyrolysis substrate mix to form a pyrolysis mixture (step  404 ). Pyrolysis method  400  may include heating the heat carrier and/or the gravity-fed baffled conduit to pyrolyze the pyrolysis substrate in the pyrolysis mixture to form a pyrolysis product mixture (step  406 ). The gravity-fed baffled conduit may include, for example, the falling bed reactor  100  described herein. 
         [0044]    In various embodiments of pyrolysis method  400 , the pyrolysis product mixture may include a gas or vapor pyrolysis product and a fine char pyrolysis product. The method may include directing the gas or vapor pyrolysis product and the fine char pyrolysis product out of the gravity-fed baffled conduit. The pyrolysis product mixture may include the heat carrier and a coarse char pyrolysis product. The method may further include directing the heat carrier and the coarse char pyrolysis product out of the gravity-fed baffled conduit. In some examples, the method may include directing the gas or vapor pyrolysis product and the fine char pyrolysis product out of the gravity-fed baffled conduit at the same level as the heat carrier and the coarse char pyrolysis product. The method may include directing the gas or vapor pyrolysis product and the fine char pyrolysis product out of the gravity-fed baffled conduit upstream compared to the heat carrier and the coarse char pyrolysis product. The method may include directing the gas or vapor pyrolysis product and the fine char pyrolysis product out of the gravity-fed baffled conduit downstream compared to the heat carrier and the coarse char pyrolysis product 
         [0045]    In some embodiments, the pyrolysis product mixture may include the heat carrier and a coarse char pyrolysis product. The method may include directing the heat carrier and the coarse char pyrolysis product out of the gravity-fed baffled conduit. 
         [0046]    In several embodiments, feeding the heat carrier to the gravity-fed baffled conduit may include feeding the heat carrier and the pyrolysis substrate to the same level in the gravity-fed baffled conduit. Feeding the heat carrier to the gravity-fed baffled conduit may include feeding the heat carrier to the gravity-fed baffled conduit upstream of the pyrolysis substrate. Feeding the heat carrier to the gravity-fed baffled conduit may include feeding the heat carrier to the gravity-fed baffled conduit downstream of the pyrolysis substrate. 
         [0047]    In various embodiments, the pyrolysis product mixture may include a gas or vapor pyrolysis product and a fine char pyrolysis product. The method may also include directing the gas or vapor pyrolysis product and the fine char pyrolysis product out of the gravity-fed baffled conduit. The method may also include separating the gas or vapor pyrolysis product from the fine char pyrolysis product. The pyrolysis product mixture may include the heat carrier and a coarse char pyrolysis product. The method may include directing the heat carrier and the coarse char pyrolysis product out of the gravity-fed baffled conduit. The method may also include separating the heat carrier from the coarse char pyrolysis product. The method may include recycling the heat carrier to form a recycled heat carrier. The method may also include feeding the recycled heat carrier to the gravity-fed baffled conduit. 
         [0048]    In several embodiments of the method, separating the heat carrier from the coarse char pyrolysis product may include directing a flow comprising a plurality of particulates along a flow axis. The method may also include separating at least a portion of a first particulate from the plurality of particulates to form a separated portion of the first particulate by directing a gas jet along a cross-flow axis, the cross-flow axis intersecting the flow axis at a cross-flow angle, the cross-flow angle being between about 70° and about 180°. As used herein, the plurality of particulates may include the heat carrier and the coarse char pyrolysis product. As used herein, the first particulate may include the coarse char pyrolysis product 
         [0049]    In various embodiments, the gas jet may include a gas temperature of between about 300° C. and about 700° C. The gas temperature may be a temperature in ° C. of about 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600, 620, 640, 660, 680, or 700, or any range between any two of the preceding temperature values. 
         [0050]    In some embodiments, the gas jet may include a gas density (in kilograms per cubic meter) of between about 0.4 and about 1.4. The gas density may have a value (in kilograms per cubic meter) of about 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, or 1.4, or any range between any two of the preceding density values. 
         [0051]    In several embodiments, the gas jet may include a gas viscosity (in kilograms per meter-second) of between about 1×10 −6  and about 1×10 −4 . For example, the gas viscosity may have a value in 10 −5  kilograms per meter-second of about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.25, 3.5, 3.75, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10, or any range between any two of the preceding gas viscosity values. 
         [0052]    In various embodiments, the gas jet may include a gas flow rate of less than 25 cubic feet per minute. The gas jet may include a gas pressure drop of less than 5 inches of for example, about 1.5 inches of water or less. 
         [0053]    In several embodiments of method  400 , separating at least the portion of the first particulate from the plurality of particulates to form the separated portion of the first particulate further may include directing the separated portion of the first particulate away from the cross-flow axis to a surface of a separator conduit. Method  400  may also include directing the separated portion of the first particulate along the surface for a distance. Directing the separated portion of the first particulate along the surface may include directing the separated portion of the first particulate substantially parallel to the first directional flow axis. Directing the separated portion of the first particulate along the surface may include using the Coand{hacek over (a)} effect. Some embodiments may include diverting the separated portion of the first particulate along the surface away from the surface to a cross-flow output. Diverting the separated portion of the first particulate along the surface away from the surface and through the cross-flow output may include using the Coand{hacek over (a)} effect. Diverting the separated portion of the first particulate along the surface away from the surface and through the cross-flow output may include contacting the separated portion of the first particulate along the surface with an entrance vane. The entrance vane may be in fluidic communication with the cross-flow output. 
         [0054]    In various embodiments of method  400 , separating at least the portion of the first particulate from the plurality of particulates may include substantially separating the first particulate from the plurality of particulates. Separating at least the portion of the first particulate from the plurality of particulates may include separating at least about 90%, 95%, 97%, 98%, 99%, 99.1%, 99.2%, 993%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, 99.95%, 99.99%, 99.995%, or 99.999% by weight of the first particulate from the plurality of particulates. For example, separating at least the portion of the first particulate from the plurality of particulates may include separating at least about 99% by weight of the first particulate from the plurality of particulates. 
         [0055]    In some embodiments, the first particulate may include one or more of a biomass or a pyrolysis product, for example, a biomass pyrolysis product. For example, the first particulate may include char. The first particulate may comprise a first average density (in kilograms per cubic meter) of between about 100 and about 2,000. For example, the first average density (in kilograms per cubic meter) may be about 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, or 2000, or between any two of the preceding density values. For example, the first average density may be about 374 kilograms per cubic meter. 
         [0056]    In several embodiments, the first particulate may be characterized by a first average diameter (in millimeters) of between about 0.1 and about 10. For example, the first average diameter (in millimeters) may be about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.4, 1.6, 1.8, 7, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, or 4, or between any two of the preceding average diameter values. 
         [0057]    In various embodiments, the first particulate may include an average flow rate (in kilograms per second) of between about 0.0012 and about 0.0023. For example, the average flow rate (in kilograms per second) may be about 0.0012, 0.0013, 0.0014, 0.0015, 0.0016, 0.0017, 0.0018, 0.0019, 0.0020, 0.0021, 0.0022, or 0.0023, or between any two of the preceding flow rate values. 
         [0058]    In some embodiments, the first particulate may include a first average density and the plurality of particulates may include at least a second particulate. The second particulate may be characterized by a second average density greater than the first average density. The second particulate may be, for example, a heat carrier suitable for use in an auger pyrolyzer. The second particulate may include one or more of a metal, a glass, a ceramic, a mineral, or a polymeric composite. For example, the second particulate may include one or more of: steel, stainless steel, cobalt (Co), molybdenum (Mo), nickel (Ni), titanium (Ti), tungsten (W), zinc (Zn), antimony (Sb), bismuth (Bi), cerium (Ce), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), manganese (Mn), rhenium (Re), iron (Fe), platinum (Pt), iridium (Ir), palladium (Pd), osmium (Os), rhodium (Rh), ruthenium (Ru), nickel, copper impregnated zinc oxide (Cu/ZnO), copper impregnated chromium oxide (Cu/Cr), nickel aluminum oxide (Ni/Al 2 O 3 ), palladium aluminum oxide (PdAl 2 O 3 ), cobalt molybdenum (CoMo), nickel molybdenum (NiMo), nickel molybdenum tungsten (NiMoW), sulfided cobalt molybdenum (CoMo), sulfided nickel molybdenum (NiMo), or a metal carbide. 
         [0059]    In several embodiments, the second average density of the second particulate (in kilograms per cubic meter) may be between about 3,000 and about 23,000, for example, about 3,000, 4,000, 5,000, 6,000, 7,000, 8,000, 9,000, 10,000, 11,000, 12,000, 13,000, 14,000, 15,000, 16,000, 17,000, 18,000, 19,000, 20,000, 21,000, 22,000, or 23,000, or between about any two of the preceding density values. For example, the second particulate may be steel or stainless steel at a density of about 7,500 kilograms per cubic meter. 
         [0060]    In various embodiments, the second average density of the second particulate divided by the first average density of the first particulate may be a ratio between about 1.5:1 and about 230:1. For example, the ratio may be about 1.5:1, 2:1, 5:1, 10:1, 15:1, 20:1, 25:1, 50:1, 75:1, 100:1, 125:1, 150:1, 175:1, 200:1, 225:1, 230:1, or a range between about any two of the preceding ratios. 
         [0061]    In some embodiments, the second particulate may be characterized by a first average diameter (in millimeters) of between about 0.1 and about 25, for example, about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or a range between about any two of the preceding average diameter values, for example, between about 1 mm and about 10 mm. 
         [0062]    In some embodiments, the second particulate may include a spherical, rounded, or ellipsoid morphology. In some embodiments, the second particulate may include a substantially spherical morphology. 
         [0063]    In several embodiments, the second participate may include a flow rate (in kilograms per second per each ton per day of biomass processed) of about 0.4 to about 1.4, for example, about 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or a range between any two of the preceding flow rates. 
         [0064]    In some embodiments, the first particulate may be characterized by a first terminal velocity and the second particulate may be characterized by a second terminal velocity. The first and second particulates may be characterized by a ratio of the second terminal velocity to the first terminal velocity of at least about 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, or 35:1. 
         [0065]    In various embodiments, method  400  may also include separating at least a portion of a second particulate in the plurality of particulates from the first particulate. For example, method  400  may include separating substantially all of a second particulate in the plurality of particulates from the first particulate. Method  400  may include separating at least a portion of a second particulate in the plurality of particulates from the first particulate in a direction substantially aligned with the first directional flow axis. The method may also include directing the flow axis downward at a flow angle. The flow angle may be less than 90° from vertically downward. The flow angle may be less than 60° from vertically downward. 
         [0066]    In several embodiments, method  400  may include forming the gas jet by flowing a gas through a first convergent nozzle. The first convergent nozzle may include a first nozzle throat. A cross section of the first nozzle throat may include at least two dissimilar axes. For example, the first nozzle throat may include an elliptical cross section, a circular cross section, a rectangular cross section, a rounded corner rectangular cross section, a polygonal cross section, a composite or combination thereof, or the like. 
         [0067]    In various embodiments, method  400  may also include adapting the flow upstream of the gas jet to a first flow diameter and adapting the flow downstream of the gas jet to a second flow diameter. The first flow diameter may be greater than the second flow diameter. The method may also include adapting the flow between the first flow diameter and the second flow diameter using a transition between the first flow diameter and the second flow diameter. The transition may be substantially aligned with the cross-flow angle. For example, the transition may be substantially perpendicular with respect to the flow axis. The transition may extend between at least a portion of the first flow diameter and at least a portion of the first nozzle throat. At least a portion of the second flow diameter may coincide with at least a portion of the first nozzle throat. The first nozzle throat may be located at the second flow diameter of the separator conduit. 
         [0068]    In some embodiments, forming the gas jet may also include flowing the gas through a second nozzle throat upstream of the first nozzle throat. 
         [0069]    In several embodiments, separating at least the portion of the first particulate from the plurality of particulates may also include extending an entrance vane into a portion of the flow defined by the second flow diameter. The method may include extending at least a portion of the entrance vane into the flow at least partly in an upstream direction with respect to the first directional flow axis. 
         [0070]    In various embodiments of method  400 , separating at least the portion of the first particulate from the plurality of particulates may include directing the separated portion of the first particulate away from the flow axis. The method may include directing the separated portion of the first particulate away from the flow axis substantially opposite to the gas jet along the cross-flow axis with respect to the first directional flow axis. 
         [0071]    In several embodiments, method  400  may include directing a separated portion of the first, articulate away from the flow axis through a third nozzle throat. A cross section of the third nozzle throat may include at least two dissimilar axes. For example, the third nozzle throat pray include an elliptical cross section, a circular cross section, a rectangular cross section, a rounded corner rectangular cross section, a polygonal cross section, a composite or combination thereof, or the like. Separating at least the portion of the first particulate from the plurality of particulates may also include directing the separated portion of the first particulate away from the third nozzle throat through an elliptical cross section. For example, the method may include directing the separated portion of the first particulate away from the third nozzle throat through a circular cross section. 
         [0072]    In some embodiments, separating at least the portion of the first particulate from the plurality of particulates further may include directing the separated portion of the first particulate away from the third nozzle throat via an exit conduit axis. The exit conduit axis may intersect the flow axis at an angle. The angle may be greater than 0° and less than 180°. For example, the angle may be between about 90° and less than 180°. In some examples, the conduit axis may be within about 30° of vertical. 
       Prophetic Example 
       [0073]    Heated spherical steel shot, about 1 mm in diameter, may be added via inlet  106  into reactor conduit  102 . Ground particulate bio-mass (e.g., a mixture of corn stover and wood particulate) may be added via pyrolysis substrate inlet  110  into reactor conduit  102 . The reactor conduit  102  and the steel shot may be heated to a desired pyrolysis temperature, e.g., 500° C. The heated steel shot and the bio-mass may fall through the one or inure baffles  114  mounted in reactor conduit  102 . The heated steel shot and the bio-mass may mix, and the bio-mass may pyrolyze to form a pyrolysis mixture including gas or vapor of bio-oil, bio-char, and the heated steel shot. A mixture of fine bio-char and the gas or vapor of bio-oil may be collected at pyrolysis product outlet  112 . A mixture of coarse bio-char and the steel shot may be collected at outlet  108 . The falling bed reactor described in this Example may exhibit effective mixing between the steel shot heat carrier and the bio-mass, similar to the mixing observed in fluidized bed reactors. The falling bed reactor described in this Example may also operate without needing inert gas, similar to the operation of auger reactors. 
         [0074]    To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use, See Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean “on” or “onto.” To the extent that the term “selectively” is used in the specification or the claims, it is intended to refer to a condition of a component wherein a user of the apparatus may activate or deactivate the feature or function of the component as is necessary or desired in use of the apparatus. To the extent that the terms “coupled” or “operatively connected” are used in the specification or the claims, it is intended to mean that the identified components are connected in a way to perform a designated function. To the extent that the term “substantially” is used in the specification or the claims, it is intended to mean that the identified components have the relation or qualities indicated with degree of error as would be acceptable in the subject industry. 
         [0075]    As used in the specification and the claims, the singular forms “a,” “an,” and “the” include the plural unless the singular is expressly specified. For example, reference to “a compound” may include a mixture of two or more compounds, as well as a single compound. 
         [0076]    As used herein, the term “about” in conjunction with a number is intended to include ±10% of the number. In other words, “about 10” may mean from 9 to 11. 
         [0077]    As used herein, the terms “optional” and “optionally” mean that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not. 
         [0078]    In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible sub-ranges and combinations of sub-ranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, and the like. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, and the like. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” include the number recited and refer to ranges which can be subsequently broken down into sub-ranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. For example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. 
         [0079]    As stated above, while the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art, having the benefit of the present application. Therefore, the application, in its broader aspects, is not limited to the specific details, illustrative examples shown, or any apparatus referred to. Departures may be made from such details, examples, and apparatuses without departing from the spirit or scope of the general inventive concept. 
         [0080]    The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.