CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 62/002,783, filed on May 23, 2014, 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, e.g., of bio-oil from bio-mass pyrolysis. The present application appreciates that efficient biomass pyrolysis may be a challenging endeavor.

SUMMARY

[0003] In one embodiment, a downflow reactor is provided. The downflow reactor may include a reactor conduit defining a flow axis. The downflow reactor may include an inlet operatively coupled to receive a heat carrier particulate into the reactor conduit. The downflow reactor may also include an outlet operatively coupled to direct the heat carrier particulate out of the reactor conduit.

[0004] In another embodiment, a downflow reactor is provided. The downflow reactor may include a reactor conduit defining a flow axis. The downflow reactor may include an inlet operatively coupled to receive a heat carrier particulate into the reactor conduit. The downflow reactor may also include an outlet operatively coupled to direct the heat carrier particulate out of the reactor conduit. The downflow reactor may further include a pyrolysis substrate inlet operatively coupled to receive a pyrolysis substrate into the reactor conduit. The downflow reactor may include a pyrolysis product outlet operatively coupled to direct a pyrolysis product out of the reactor conduit.

[0005] In one embodiment, a dual bed pyrolysis system is provided. The dual bed pyrolysis system may include a downflow reactor. The downflow reactor may include a reactor conduit defining a flow axis. The downflow reactor may include an inlet operatively coupled to receive a heat carrier particulate into the reactor conduit. The downflow reactor may include an outlet operatively coupled to direct the heat carrier particulate out of the reactor conduit. The dual bed pyrolysis system may also include a fluidized bed reactor. The fluidized bed reactor may include a fluidized bed char combustion chamber. The fluidized bed reactor may include a flow input and a flow output in fluidic communication with the fluidized bed char combustion chamber. The outlet of the downflow reactor may be operatively coupled to the flow input of the fluidized bed reactor. The flow output of the fluidized bed reactor may be operatively coupled to the inlet of the downflow reactor.

[0006] In one embodiment, a pyrolysis system is provided. The pyrolysis system may include a downflow reactor and a cross-flow classifier. The downflow reactor may include a reactor conduit defining a flow axis. The downflow reactor may include an inlet operatively coupled to receive a heat carrier particulate into the reactor conduit. The downflow reactor may also include an outlet operatively coupled to direct the heat carrier particulate out of the reactor conduit. The downflow reactor may further include a pyrolysis substrate inlet operatively coupled to receive a pyrolysis substrate into the reactor conduit. The downflow reactor may include a pyrolysis product outlet operatively coupled to direct a pyrolysis product out of the reactor conduit.

[0007] 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 downflow 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 downflow reactor.

[0008] In another embodiment, a method for pyrolyzing a substrate is provided. The method may include feeding a heat carrier particulate to a gravity-fed conduit. The method may include feeding a pyrolysis substrate to the gravity-fed conduit such that the heat carrier particulate and the pyrolysis substrate mix to form a pyrolysis mixture. The method may include heating the heat carrier particulate and/or the gravity-fed conduit to pyrolyze the pyrolysis substrate in the pyrolysis mixture to form a pyrolysis product mixture and a pyrolysis waste mixture. The pyrolysis waste mixture may include the heat carrier particulate and a coarse char pyrolysis product. The method may include combusting the coarse char pyrolysis product in the presence of the heat carrier particulate to reheat the heat carrier particulate. [0009] In one embodiment, a pyrolysis method is provided. The pyrolysis method may include feeding a heat carrier particulate to a gravity-fed conduit. The pyrolysis method may include feeding a pyrolysis substrate to the gravity-fed conduit such that the heat carrier particulate and the pyrolysis substrate mix to form a pyrolysis mixture. The pyrolysis method may include heating the heat carrier particulate and/or the gravity-fed conduit to pyrolyze the pyrolysis substrate in the pyrolysis mixture to form a pyrolysis product mixture. The "gravity-fed conduit" may include, for example, the downflow reactor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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.

[0011] FIG. 1A depicts an example downflow reactor. [0012] FIG. IB depicts an example downflow reactor.

[0013] FIG. 1C depicts an example downflow reactor with a diverging geometry.

[0014] FIG. ID depicts an example downflow reactor with a converging geometry.

[0015] FIG. IE depicts an example downflow reactor with a combined diverging- converging geometry.

[0016] FIG. IF depicts an example downflow reactor with a combined diverging- converging geometry equipped with a mixing chamber.

[0017] FIG. 1G depicts an example downflow reactor with a combined diverging- converging geometry equipped with a mixing chamber.

[0018] FIG. 1H depicts an example downflow reactor with a diverging geometry equipped with a mixing nozzle. [0019] FIG. II depicts an example downflow reactor with a diverging geometry equipped with a mixing nozzle

[0020] FIG. 2A depicts an example pyrolysis system that includes an example downflow reactor and an example fluidized bed.

[0021] FIG. 2B depicts an example pyrolysis system that includes an example downflow reactor and an example cross-flow particle classifier.

[0022] FIG. 3 is a block diagram of an example cross-flow particle classifier.

[0023] FIG. 4A is a flow diagram of an example method for pyrolysis using both downflow pyrolysis and fluidized bed combustion.

[0024] FIG. 4B is a flow diagram of an example method for pyrolysis using both downflow pyrolysis and fluidized bed combustion.

[0025] FIG. 5 is a flow diagram of an example method for pyrolysis using both downflow pyrolysis and a cross-flow particle classifier.

DETAILED DESCRIPTION

[0026] FIG. 1A depicts an example downflow reactor 100A. Downflow reactor 100A 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. Downflow reactor 100A may include an inlet 106 operatively coupled to receive a heat carrier particulate into reactor conduit 102. Downflow reactor 100A may also include an outlet 108 operatively coupled to direct the heat carrier particulate out of reactor conduit 102. Downflow reactor 100A may further include a pyrolysis substrate inlet 110 operatively coupled to receive a pyrolysis substrate into reactor conduit 102. Downflow reactor 100A may include a pyro lysis product outlet 112 operatively coupled to direct a pyrolysis product out of reactor conduit 102.

[0027] In various embodiments, downflow reactor 100A 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. Downflow reactor 100A may be mounted to orient flow axis 104 in a substantially vertically downward direction. In this manner, downflow reactor 100A may be gravity-fed or gravity operated, at least in part. For example, the pyrolysis substrate may enter downflow reactor 100A at pyrolysis substrate inlet 110, and the heat carrier particulate may enter downflow reactor 100A at inlet 106. The pyrolysis substrate and the heat carrier particulate may fall through downflow reactor 100A.

[0028] In some embodiments, a cross section of reactor conduit 102 may include a shape that may be one of: polygonal, rounded polygonal, circular, elliptical, rectangular, rounded rectangular, a combination or composite thereof, and the like. For example, reactor conduit 102 may be square in cross section.

[0029] In several embodiments, one or both of inlet 106 and outlet 108 may be at an angle with one or both of reactor conduit 102 and flow axis 104, for example from about substantially parallel with one or both of reactor conduit 102 and flow axis 104 to about substantially perpendicular with one or both of reactor conduit 102 and flow axis 104. One or both of inlet 106 and outlet 108 may be within or emerging from a sidewall of conduit 102 (not shown). Inlet 106 may be operatively coupled to reactor conduit 102 upstream of outlet 108 with respect to flow axis 104.

[0030] In some embodiments, downflow reactor 100A may include a pyrolysis substrate inlet 110 operatively coupled to receive a pyrolysis substrate into reactor conduit 102. Downflow reactor 100A may include a pyrolysis product outlet 112 operatively coupled to direct a pyrolysis product out of reactor conduit 102. [0031] 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.

[0032] In several embodiments, downflow reactor 100A may include an agitator mechanism 126 configured to agitate at least a portion of reactor conduit 102 effective to dislodge a particulate on at least a portion of reactor conduit 102. Downflow reactor 100A may include a heater 128. Heater 128 may be configured to cause pyrolysis of a substrate in downflow reactor 100A by heating one or both of downflow reactor 100A and a heat carrier particulate to be fed into downflow reactor 100A.

[0033] 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 104. "Vertically upward" means antiparallel with respect to the local gravitational acceleration direction. As used herein, "horizontal" means perpendicular to the local gravitational acceleration direction. In some embodiments, the flow axis 104 of downflow reactor 100A may be, in degrees from vertical, within about +30 ^° , +25 ^° , +20 ^° , ± 15 ^° , ± 14 ^° , ± 13 ^° , ± 12 ^° , ± 11 ^° , ± 10 ^° , ±9 ^° , ±8 ^° , ±7 ^° , ±6 ^° , ±5 ^° , ±4 ^° , ±3 ^° , ±2 ^° , ± 1 ^° , or ±0.5 ^° . [0034] As used herein, an "oblique angle" is any angle between about horizontal, e.g., about 90 ^° or perpendicular with respect to flow axis 104, and about vertically downward, e.g., about parallel or 0 ^° , e.g., with respect to flow axis 104. In some embodiments, an oblique angle may be an angle in degrees with respect to flow axis 104 of about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85, e.g., about 45 ^° , or a range between any two of the preceding values, e.g., between about 20 ^° and about 70 ^° , between 30 ^° and about 60 ^° , between about 40 ^° and about 50 ^° , and the like.

[0035] 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, a mineral, a silica, a catalyst, a char, an ash, a silica, a polymeric composite, or the like. The characteristics of the particles in the particulate may be a combination of material compositions, for example, particles in a particulate may be mixtures of different compositions, e.g., two or more of: a ceramic, a metal, a mineral, a catalyst, a silica, a char, and the like. In another example, particles in a particulate may be characterized by a distribution of particle sizes, for example, a Gaussian distribution. Particles in a particulate may be characterized by a bimodal distribution of particle size.

[0036] FIG. IB depicts an alternate example of a downflow reactor 100B. Compared to downflow reactor 100A, downflow reactor 100B omits pyrolysis substrate inlet 110 and pyrolysis product outlet 112. In downflow reactor 100B, pyrolysis substrates and heat carrier particulates may both be introduced through inlet 106. Similarly, pyrolysis products and heat carrier particulates may both be removed via outlet 108.

[0037] Downflow reactors 100A and 100B are depicted with constant cross sections along flow axis 104. By contrast, FIG. 1C depicts an example downflow reactor lOOC with a diverging geometry along flow axis 104. FIG. ID depicts an example downflow reactor 100D with a converging geometry along flow axis 104. FIG. IE depicts an example downflow reactor 100E with a combined diverging-converging geometry along flow axis 104. Biomass and heat carrier particulate may be introduced at inlet 106, and may collect as solid pyrolysis waste/heat carrier particulate 150 near outlet 108, and may be removed by agitator 126. A downflow reactor may have a combined converging-diverging geometry (not shown), with the narrowest cross section located intermediate along flow axis 104.

[0038] Any of downflow reactors 100A, 100B, lOOC, 100D, or 100E may be substituted for each other in the various embodiments and methods described herein.

[0039] FIG. IF depicts an example downflow reactor with a combined diverging- converging geometry 100E equipped with a mixing chamber 100F. Mixing chamber 100F may accept heat carrier particulate via inlet 106 and pyrolysis substrate via inlet 110. The mixed heat carrier particulate and pyrolysis substrate may then be accepted by downflow reactor 100E. Mixing chamber 100F may be combined with any other example downflow reactor described herein.

[0040] FIG. 1G depicts an example downflow reactor with a combined diverging- converging geometry 100E equipped with a mixing chamber 100F and additional inlets 106'. As the heat carrier particulate and pyrolysis substrate mix, and heat is transferred from the heat carrier particulate to the pyrolysis substrate and pyrolysis products, the heat carrier particulate may cool. Additional heat carrier particulate may be added, for example at inlets 106' to add more heat to the pyrolysis. Additional inlets 106' may be combined with any other example downflow reactor described herein.

[0041] FIG. IF depicts an example downflow reactor with a diverging geometry lOOC equipped with a mixing nozzle 100H. Mixing nozzle 100H may accept heat carrier particulate via inlet 106 and pyrolysis substrate via inlet 110, with mixing in mixing nozzle 100H aided by deflector 107. The mixed heat carrier particulate and pyrolysis substrate may then be accepted by downflow reactor lOOC. Mixing nozzle 100H may be combined with any other example downflow reactor described herein.

[0042] FIG. II depicts an example downflow reactor with a diverging geometry lOOC equipped with a mixing nozzle 1001. Mixing nozzle 1001 may accept heat carrier particulate via inlet 1061 and pyrolysis substrate via inlet 1101, with mixing in mixing nozzle 1001 aided by deflectors 109. The mixed heat carrier particulate and pyrolysis substrate may then be accepted by downflow reactor lOOC. Mixing nozzle 1001 may be combined with any other example downflow reactor described herein.

[0043] FIG. 2A depicts an example dual bed pyrolysis system 200A. Pyrolysis system 200A may include downflow reactor 100A and a fluidized bed reactor 202. Downflow reactor 100A 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. Downflow reactor 100A may include an inlet 106 operatively coupled to receive a heat carrier particulate into reactor conduit 102. Downflow reactor 100A may also include an outlet 108 operatively coupled to direct the heat carrier particulate out of reactor conduit 102. Downflow reactor 100A may further include a pyrolysis substrate inlet 110 operatively coupled to receive a pyrolysis substrate into reactor conduit 102. Downflow reactor 100A may include a pyro lysis product outlet 112 operatively coupled to direct a pyrolysis product out of reactor conduit 102.

[0044] As used herein, a heat carrier particulate suitable for use in the example reactors described herein may include one or more of: a mineral, a glass, a ceramic, a silica, a polymeric composite, a char, an ash, a catalyst, a metal, and the like. The heat carrier particulate may include a mineral, e.g., quartz sand. The heat carrier particulate may include a glass, e.g., silicate glass. The heat carrier particulate may include a ceramic, e.g., an alumina ceramic. The heat carrier particulate may include the char. The heat carrier particulate may include an ash, e.g., carbonates, oxides, sulfates, and the like of one or more of: sodium, potassium, calcium, iron, magnesium, phosphorus, zinc, tin, titanium, sulfur, and the like.

[0045] In several embodiments, the particulate catalyst may be used as the heat carrier particulate and the pyrolysis vapor may be catalyzed in situ in the falling bed reactor, producing an upgraded bio-oil vapor in one step, and upgraded bio-oil when condensed. The heat carrier particulate may be in the form of metal shot, for example, steel shot.

[0046] In various embodiments, the heat carrier 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 (N1/AI2O ₃ ), palladium aluminum oxide (PdA^C^), cobalt molybdenum (CoMo), nickel molybdenum (NiMo), nickel molybdenum tungsten (NiMoW), sulfided cobalt molybdenum (CoMo), sulfided nickel molybdenum (NiMo ), a metal carbide, and the like. The heat carrier particulate may include an oxide, carbonate, sulfate, or the like of one or more of the preceding metals.

[0047] In some embodiments, the heat carrier particulate may be inert. The heat carrier particulate may include a catalytically active particulate or may include a particulate catalyst. For example, the heat carrier particulate may include particles of one or more of a catalytically active: metal, metal oxide, metal carbonate, metal sulfate, zeolite, char, ash, and the like. The heat carrier particulate may include a recycled or spent particulate catalyst, e.g., a fluid catalytic cracking (FCC) catalyst. The heat carrier particulate may include a spent particulate catalyst, e.g., a spent FCC catalyst. Catalytically active particulates may have various activities. Various FCC catalysts may, e.g., increase cracking of carbon-oxygen, e.g., ether bonds during pyrolysis. For example, catalytic effects of FCC catalysts may include one or more of: increased generation of gaseous, e.g., C1-C4 hydrocarbons; increased generation of oxygen-containing species, e.g., H ₂ 0, CO, CO2, and the like; production of upgraded bio-oil characterized by one or more of decreased viscosity, decreased oxygen content, increased heat value, decreased acid value, decreased hydroxyl value, and the like. Catalytically active char, for example, may lead to increased cracking and/or condensation reactions. Catalytically active ash may have similar effects as FCC catalysts, e.g., increased cracking of carbon-oxygen, e.g., ether bonds during pyrolysis. Effects of catalytically active ash may include one or more effects described for FCC catalysts.

[0048] In several embodiments, the heat carrier particulate may include a catalyst and a non-catalyst. A heat carrier particulate including a mixture of a catalyst and a non-catalyst may include a catalyst present in an amount in wt % of at least about one or more of: 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, and 85. A heat carrier particulate including a mixture of a catalyst and a non-catalyst may include a catalyst present in an amount in wt % between any of the preceding values, for example, between about 15 and about 40, or between about 20 and about 80. A heat carrier particulate including a mixture of a catalyst and a non-catalyst may include a catalyst present in an amount at least about 1 wt %. A heat carrier particulate including a mixture of a catalyst and a non-catalyst may include a catalyst present in an amount up to about 99 wt %.

[0049] In various embodiments, the heat carrier particulate may include an average particle size in μιη of about one or more of: 20 μιη, 30 μιη, 40 μιη, 50 μιη, 75 μιη, 0.1 mm, 0.25 mm, 0.5 mm, 0.75 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 7.5 mm, and 10 mm; or a range between any two of the preceding values, for example, between about 20 μιη and about 10 mm, between about 50 μιη and about 0.75 mm, and the like.

[0050] The particulate catalyst may be used as the heat carrier particulate and the pyrolysis vapor may be catalyzed in situ in the downflow reactor, producing an upgraded bio- oil vapor in one step, and upgraded bio-oil when condensed. The heat carrier particulate may be in the form of metal shot, for example, steel shot. In various embodiments, the heat carrier particulate, when employed with the cross flow particle classifier, is of a density effective to provide separation between the heat carrier particulate and the char to be separated in the cross flow particle classifier.

[0051] Fluidized bed reactor 242 may include a fluidized bed char combustion chamber 244. Fluidized bed reactor 242 may also include a flow input 246 and a flow output 248 in fluidic communication with fluidized bed char combustion chamber 244. In some embodiments, flow input 246 and flow output 248 may be on opposite sides of fluidized bed char combustion chamber 244 to define a flow path 250 extending from flow input 246, into fluidized bed char combustion chamber 244, and to flow output 248. Flow input 246 may be located upstream of flow output 248 with respect to flow axis 250. Further with respect to pyrolysis system 200A, outlet 108 of downflow reactor 100A may be operatively coupled to flow input 246 of fluidized bed reactor 242. Also, flow output 248 of fluidized bed reactor 242 may be operatively coupled to inlet 106 of downflow reactor 100A.

[0052] In various embodiments, outlet 108 of downflow reactor 100A may be operatively coupled to flow input 246 of fluidized bed reactor 242 via an auger or conveyor 252. Flow output 248 of fluidized bed reactor 242 may be operatively coupled to inlet 106 of downflow reactor 100A via an auger or conveyor 254. In another embodiment, the downflow reactor 100A may be physically lowered in elevation relative to fluidized bed reactor 242 such that the inlet 106 of the downflow reactor 100A is lower in elevation than the outlet 248 of the fluidized bed reactor 242. In this embodiment flow output 248 of fluidized bed reactor 242 may be operatively coupled to inlet 106 of downflow reactor 100A via a simple downward sloping pipe or duct 254. In another embodiment, the downflow reactor 100A may be physically raised in elevation relative to fluidized bed reactor 242 such that the outlet 108 of the downflow reactor 100A is higher in elevation than the inlet 246 of the fluidized bed reactor 242. In this embodiment flow output 108 of downflow reactor 100A may be operatively coupled to inlet 606 of fluidized bed reactor 242 via a simple downward sloping pipe or duct 252.

[0053] In some embodiments, dual bed pyrolysis system 200A 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 downflow reactor 100A. 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, a scrubber, and the like. Fine particulate separator 202 may separate, for example, fine char produced during the pyrolysis of the biomass in downflow reactor 100A. The fine char may be entrained in pyrolysis gas exiting downflow reactor 100A via pyrolysis product outlet 112. Large char particulates that may be too heavy or too large to be entrained in pyrolysis gas exiting downflow reactor 100A may exit at outlet 108 along with spent heat carrier particulate. Auger or conveyor or downward sloping pipe 252 may transport the spent heat carrier particulate and the large char particulates to flow input 246 of fluidized bed reactor 242, and into fluidized bed char combustion chamber 244. The large char particulates may be combusted in fluidized bed char combustion chamber 244. Combustion of the large char particulates in fluidized bed char combustion chamber 244 may dispose of the large char particulates. Combustion of the large char particulates in fluidized bed char combustion chamber 244 may also heat the spent heat carrier particulate to provide reheated heat carrier particulate suitable for further pyrolysis. The reheated heat carrier particulate produced by combustion of the large char particulates in fluidized bed char combustion chamber 244 may exit fluidized bed char combustion chamber 244 at flow output 248. Flow output 248 of fluidized bed reactor 242 may be operatively coupled to inlet 106 of downflow reactor 100A via auger or conveyor or downward sloping pipe 254. Auger or conveyor 254 or the force of gravity in a downward sloping pipe may transport the reheated heat carrier particulate from flow output 248 of fluidized bed reactor 242 to inlet 106 to be combined with biomass for further pyrolysis in downflow reactor 100A.

[0054] FIG. 2B depicts an example pyrolysis system 200B. Pyrolysis system 200B may include downflow reactor 100A and a cross-flow classifier 3100. Downflow reactor 100A 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. Downflow reactor 100A may include an inlet 106 operatively coupled to receive a heat carrier particulate into reactor conduit 102. Downflow reactor 100A may also include an outlet 108 operatively coupled to direct the heat carrier particulate out of reactor conduit 102. Downflow reactor 100A may further include a pyrolysis substrate inlet 110 operatively coupled to receive a pyrolysis substrate into reactor conduit 102. Downflow reactor 100A may include a pyrolysis product outlet 112 operatively coupled to direct a pyrolysis product out of reactor conduit 102.

[0055] 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 at 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 200B, outlet 108 of downflow reactor 100A 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 downflow reactor 100A.

[0056] In various embodiments, outlet 108 of downflow reactor 100A 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 downflow reactor 100A via an auger or conveyor 232.

[0057] In some embodiments, pyrolysis system 200B 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 downflow reactor 100A. 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, a scrubber, and the like.

[0058] In several embodiments, pyrolysis system 200B 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, a scrubber, and the like.

[0059] In various embodiments, pyrolysis system 200B 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.

[0060] In further embodiments, downflow reactor 100A in pyrolysis system 200B may include any aspect of downflow reactor 100A described herein.

[0061] FIG. 3 depicts aspects of cross-flow classifier 3100 that may be used in example pyrolysis system 200B. 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. [0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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, a mineral, a catalyst, a silica, a char, an ash, a polymeric composite, or the like. In another example, particles in a particulate may be characterized by a distribution of particle sizes, for example, a Gaussian distribution. Particles in a particulate may be characterized by a bimodal distribution of particle size.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] FIG. 4A shows a flow diagram of an example method 400A for pyrolysis using both downflow pyrolysis and fluidized bed combustion. Method 400A may include 402 feeding a heat carrier particulate to a gravity-fed conduit. Method 400A may include 404 feeding a pyrolysis substrate to the gravity-fed conduit such that the heat carrier particulate and the pyrolysis substrate mix to form a pyrolysis mixture. Method 400A may include 406 heating the heat carrier particulate and/or the gravity-fed conduit to pyrolyze the pyrolysis substrate in the pyrolysis mixture to form a pyrolysis product mixture and a pyrolysis waste mixture. The pyrolysis waste mixture may include the heat carrier particulate and a coarse char pyrolysis product. The method may optionally include 408 combusting the coarse char pyrolysis product in the presence of the heat carrier particulate to reheat the heat carrier particulate.

[0073] FIG. 4B shows a flow diagram of an example method 400B for pyrolysis using both downflow pyrolysis and fluidized bed combustion. Method 400B may include 402 feeding a heat carrier particulate to a gravity-fed conduit. Method 400B may include 404 feeding a pyrolysis substrate to the gravity-fed conduit such that the heat carrier particulate and the pyrolysis substrate mix to form a pyrolysis mixture. Method 400B may include 406 heating the heat carrier particulate and/or the gravity-fed conduit to pyrolyze the pyrolysis substrate in the pyrolysis mixture to form a pyrolysis product mixture and a pyrolysis waste mixture. The pyrolysis waste mixture may include the heat carrier particulate and a coarse char pyrolysis product. Compared to method 400A, method 400B may include 408 combusting the coarse char pyrolysis product in the presence of the heat carrier particulate to reheat the heat carrier particulate. [0074] FIG. 5 is a flow diagram describing an example pyrolysis method 500. Pyrolysis method 500 may include feeding a heat carrier particulate to a gravity-fed conduit (step 502). Pyrolysis method 500 may include feeding a pyrolysis substrate to the gravity-fed conduit such that the heat carrier particulate and the pyrolysis substrate mix to form a pyrolysis mixture (step 504). Pyrolysis method 500 may include heating the heat carrier particulate and/or the gravity-fed conduit to pyrolyze the pyrolysis substrate in the pyrolysis mixture to form a pyrolysis product mixture (step 506). The gravity-fed conduit may include, for example, the downflow reactor 100A described herein.

[0075] In various embodiments of pyrolysis method 500, 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 conduit. The pyrolysis product mixture may include the heat carrier particulate and a coarse char pyrolysis product. The method may further include directing the heat carrier particulate and the coarse char pyrolysis product out of the gravity-fed 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 conduit at the same level as the heat carrier particulate 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 conduit upstream compared to the heat carrier particulate 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 conduit downstream compared to the heat carrier particulate and the coarse char pyrolysis product

[0076] In some embodiments, the pyrolysis product mixture may include the heat carrier particulate and a coarse char pyrolysis product. The method may include directing the heat carrier particulate and the coarse char pyrolysis product out of the gravity-fed conduit. [0077] In several embodiments, feeding the heat carrier particulate to the gravity-fed conduit may include feeding the heat carrier particulate and the pyrolysis substrate to the same level in the gravity-fed conduit. Feeding the heat carrier particulate to the gravity-fed conduit may include feeding the heat carrier particulate to the gravity-fed conduit upstream of the pyrolysis substrate. Feeding the heat carrier particulate to the gravity-fed conduit may include feeding the heat carrier particulate to the gravity-fed conduit downstream of the pyrolysis substrate.

[0078] 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 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 particulate and a coarse char pyrolysis product. The method may include directing the heat carrier particulate and the coarse char pyrolysis product out of the gravity-fed conduit. The method may also include separating the heat carrier particulate from the coarse char pyrolysis product. The method may include recycling the heat carrier particulate to form a recycled heat carrier particulate. The method may also include feeding the recycled heat carrier particulate to the gravity-fed conduit.

[0079] In several embodiments of the method, separating the heat carrier particulate 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 particulate and the coarse char pyrolysis product. As used herein, the first particulate may include the coarse char pyrolysis product

[0080] 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.

[0081] 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.

[0082] In several embodiments, the gas jet may include a gas viscosity (in kilograms per meter-second) of between about lxlO ^"6 and about lxlO ^"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.

[0083] 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.

[0084] In several embodiments of method 500, 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 500 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 Coanda 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 Coanda 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.

[0085] In various embodiments of method 500, 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%, 99.3%, 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.

[0086] 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, 1 100, 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.

[0087] 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, 2, 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.

[0088] 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.

[0089] 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 particulate suitable for use in an auger pyrolyzer. The second particulate may include one or more of a metal, a glass, a ceramic, a mineral, a catalyst, a silica, a char, an ash, a polymeric composite, and the like. 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 ( b), 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 (N1/AI2O ₃ ), palladium aluminum oxide (PdA^C^), cobalt molybdenum (CoMo), nickel molybdenum (NiMo), nickel molybdenum tungsten (NiMoW), sulfided cobalt molybdenum (CoMo), sulfided nickel molybdenum (NiMo ), a metal carbide, and the like.

[0090] 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, 1 1,000, 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.

[0091] 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.

[0092] 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, 1 1, 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.

[0093] 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.

[0094] In several embodiments, the second particulate 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. [0095] 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.

[0096] In various embodiments, method 500 may also include separating at least a portion of a second particulate in the plurality of particulates from the first particulate. For example, method 500 may include separating substantially all of a second particulate in the plurality of particulates from the first particulate. Method 500 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. Method 500 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.

[0097] In several embodiments, method 500 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.

[0098] In various embodiments, method 500 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.

[0099] In some embodiments, forming the gas jet may also include flowing the gas through a second nozzle throat upstream of the first nozzle throat.

[00100] 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.

[00101] In various embodiments of method 500, 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.

[00102] In several embodiments, method 500 may include directing a separated portion of the first particulate 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 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. 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.

[00103] 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 exit conduit axis may be within about 30° of vertical.

[00104] In various embodiments, a dual bed pyrolysis system 200A is provided. Dual bed pyrolysis system 200A may include a downflow reactor 100A. Downflow reactor 100A may include a reactor conduit 102 defining a flow axis 104. Downflow reactor 100A may include an inlet 106 operatively coupled to receive a heat carrier particulate into the reactor conduit 102. Downflow reactor 100A may include an outlet 108 operatively coupled to direct the heat carrier particulate out of the reactor conduit 102. Dual bed pyrolysis system 200A may also include a fluidized bed reactor 242. Fluidized bed reactor 242 may include a fluidized bed char combustion chamber 244. Fluidized bed reactor 242 may include a flow input 246 and a flow output 248 in fluidic communication with fluidized bed char combustion chamber 244. Outlet 108 of downflow reactor 100A may be operatively coupled to flow input 246 of fluidized bed reactor 242. Flow output 248 of fluidized bed reactor 242 may be operatively coupled to inlet 106 of downflow reactor 100A.

[00105] In some embodiments, downflow reactor 100A may include a pyrolysis substrate inlet 110 operatively coupled to receive a pyrolysis substrate into reactor conduit 102. Downflow reactor 100A may include a pyrolysis product outlet 112 operatively coupled to direct a pyrolysis product out of reactor conduit 102. [00106] In some embodiments, dual bed pyrolysis system 200A may include an auger or conveyor or downward sloping pipe 252. Outlet 108 of downflow reactor 100A may be operatively coupled to flow input 246 of fluidized bed reactor 242 via auger or conveyor or downward sloping pipe 252. Dual bed pyrolysis system 200A may include an auger or conveyor or downward sloping pipe 254. Flow output 248 of fluidized bed reactor 242 may be operatively coupled to inlet 106 of downflow reactor 100A via auger or conveyor or downward sloping pipe 254.

[00107] In some embodiments, dual bed pyrolysis system 200A may include a fine particulate separator 202. An input 204 of the fine particulate separator 202 may be operatively coupled to pyrolysis product outlet 112 of downflow reactor 100A. The fine particulate separator 202 may include a particulate outlet 206 and a gas or vapor outlet 208. The 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, a scrubber, and the like.

[00108] In several embodiments, downflow reactor 100A may be configured to be mounted such that at least a portion of flow axis 104 may be parallel or oblique to a vertically downwards direction. Downflow reactor 100A may be mounted to orient the flow axis 104 in a substantially vertically downwards direction.

[00109] In various embodiments, a cross section of reactor conduit 102 may include a shape that is one of: polygonal, rounded polygonal, circular, elliptical, rectangular, rounded rectangular, a combination or composite thereof, and the like. For example, the cross section of the reactor conduit 102 may be square.

[00110] In some 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.

[00111] In several embodiments, inlet 106 may be operatively coupled to receive a pyrolysis substrate into the reactor conduit 102. Outlet 108 may be operatively coupled to direct a pyrolysis product out of the reactor conduit 102.

[00112] In some embodiments, the dual bed pyrolysis system 200A may include a pyrolysis substrate inlet 110 operatively coupled to receive a pyrolysis substrate into the reactor conduit 102. A pyrolysis product outlet 112 may be included and may be operatively coupled to direct a pyrolysis product out of the reactor conduit 102.

[00113] In several embodiments, a fine particulate separator 202 may be included. An input 204 of the fine particulate separator 202 may be operatively coupled to the pyrolysis product outlet 112 of the downflow reactor 100A. The fine particulate separator 202 may include a particulate outlet 206 and a gas or vapor outlet 208.

[00114] In several embodiments, 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.

[00115] In various embodiments, dual bed pyrolysis system 200A may include an agitator mechanism 126 configured to agitate at least a portion of reactor conduit 102 effective to dislodge a particulate on at least a portion of reactor conduit 102. A heater 128 may be configured to cause pyrolysis of a substrate in downflow reactor 100A by heating one or both of downflow reactor 100A and a heat carrier particulate to be fed into downflow reactor 100A.

[00116] In various embodiments, dual bed pyro lysis system 200A may be configured to employ the heat carrier particulate comprising one or more of: a metal, a glass, a ceramic, a mineral, or a polymeric composite. For example, the heat carrier particulate may be sand. The heat carrier particulate may include a particulate catalyst. For example, the heat carrier particulate may include a fluid catalytic cracking (FCC) catalyst. The heat carrier particulate may include a spent particulate catalyst. For example, the heat carrier particulate may include a spent FCC catalyst.

[00117] In various embodiments, the downflow reactor may be configured with a reactor conduit 102 that has a geometry along flow axis 104 that is one or more of: constant, diverging, converging, diverging-converging, and converging-diverging. The downflow reactor may be configured with a mixing chamber 100F or a mixing nozzle 100H.

[00118] In various embodiments, a method 400A for pyrolyzing a substrate is provided. The method may include 402 feeding a heat carrier particulate to a gravity-fed conduit. The method may include 404 feeding a pyrolysis substrate to the gravity-fed conduit such that the heat carrier particulate and the pyrolysis substrate mix to form a pyrolysis mixture. The method may include 406 heating the heat carrier particulate and/or the gravity- fed conduit to pyrolyze the pyrolysis substrate in the pyrolysis mixture to form a pyrolysis product mixture and a pyrolysis waste mixture. The pyrolysis waste mixture may include the heat carrier particulate and a coarse char pyrolysis product. The method may optionally include 408 combusting the coarse char pyrolysis product in the presence of the heat carrier particulate to reheat the heat carrier particulate.

[00119] In several embodiments, the method may include feeding the reheated heat carrier particulate to the gravity-fed conduit. The method may include directing the heat carrier particulate and the coarse char pyrolysis product out of the gravity-fed conduit prior to combusting the coarse char pyrolysis product in the presence of the heat carrier particulate to reheat the heat carrier particulate.

[00120] In some embodiments, 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 conduit. The method may include directing the gas or vapor pyrolysis product and the fine char pyrolysis product out of the gravity-fed conduit at the same level as the heat carrier particulate 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 conduit upstream compared to the heat carrier particulate 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 conduit downstream compared to the heat carrier particulate and the coarse char pyrolysis product. The method may include directing the heat carrier particulate and the coarse char pyrolysis product out of the gravity-fed conduit. The method may include feeding the heat carrier particulate to the gravity-fed conduit including feeding the heat carrier particulate and the pyrolysis substrate at the same level of the gravity-fed conduit. The method may include feeding the heat carrier particulate to the gravity-fed conduit including feeding the heat carrier particulate to the gravity-fed conduit upstream of the pyrolysis substrate. The method may include feeding the heat carrier particulate to the gravity-fed conduit including feeding the heat carrier particulate to the gravity-fed conduit downstream of the pyrolysis substrate.

[00121] In several embodiments, 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 conduit. The method may include separating the gas or vapor pyrolysis product from the fine char pyrolysis product.

[00122] In various embodiments, the heat carrier particulate may include one or more of: a metal, a glass, a ceramic, a mineral, a catalyst, a char, an ash, a silica, a polymeric composite, and the like. The heat carrier particulate may be, for example, a mixture of one or more of: a metal, a glass, a ceramic, a mineral, a char, a silica, a catalyst, and a polymeric composition, for example, a mixture of a catalyst, a sand, a char, and the like. For example, the heat carrier particulate may be sand. For example, the heat carrier particulate may be a metal carbonate. The heat carrier particulate may include a particulate catalyst. For example, the heat carrier particulate may include a fluid catalytic cracking (FCC) catalyst. The heat carrier particulate may include a spent particulate catalyst. For example, the heat carrier particulate may include a spent FCC catalyst. The heat carrier particulate may include one or more of: a zeolite and a metal oxide.

PROPHETIC EXAMPLE 1

[00123] 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 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 downflow reactor described in this Example may exhibit effective mixing between the steel shot heat carrier particulate and the bio mass, similar to the mixing observed in fluidized bed reactors. The downflow reactor described in this Example may also operate without needing inert gas.

PROPHETIC EXAMPLE 2

[00124] A dual bed reactor may be constructed according to the design of the dual bed pyrolysis system 200A. Heated sand may be added via inlet 106 into reactor conduit 102. Ground particulate bio mass may be added via pyrolysis substrate inlet 110 into reactor conduit 102. The reactor conduit 102 and the sand may be heated to between about 400 C and about 800 C. The sand and the bio mass may fall through the reactor conduit 102. The sand and the bio mass may mix, and the bio mass may pyrolyze to form a pyrolysis mixture including vaporized bio-oil, bio char, and the heated sand. A mixture of fine bio char entrained in the bio-oil vapor may be collected at pyrolysis product outlet 112. A mixture of coarse bio char and the sand may be collected at outlet 108. The mixture of coarse bio char and the sand may be transported via auger 252 to flow input 246 of fluidized bed reactor 242, and into fluidized bed char combustion chamber 244. The coarse bio char may be combusted in the fluidized bed char combustion chamber 244 at a temperature of between 400 °C to 800 °C. Combusting the coarse bio char in the fluidized bed char combustion chamber 244 may heat the sand to a temperature of about 400 °C to 800 °C. The reheated sand may exit fluidized bed char combustion chamber 244 at flow output 248. The reheated sand may be transported by auger 254 from flow output 248 of fluidized bed reactor 242 to inlet 106 and combined with biomass for further pyrolysis in downflow reactor 100A. The dual bed reactor system of this Example may be operated at a biomass input rate of about 1 ton per day, producing about 50% to 75% of bio-oil yield per day on a dry mass basis.

[00125] 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 "operatively 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.

[00126] 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.

[00127] 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 1 1.

[00128] 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. [00129] 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.

[00130] 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.