JP2014518325A - System for roasting lignocellulosic materials - Google Patents

Abstract

  A pressure roasting reaction vessel, a rotatable shaft extending vertically down through the top of the reaction vessel; a plurality of scraper devices, each at a different height in the reaction vessel, attached to the shaft; Cooperating with each one of the plurality of scraper devices, whereby the scraper device includes a tray directly above the tray of the tray assembly, the tray being open mesh or allowing gas flow to pass through the tray Are impermeable to the passage of biomass, each of the trays including a discharge opening for transporting the biomass from the tray to one lower tray of the tray assembly, wherein the discharge opening in the bottom tray assembly is The biomass is transported to the biomass accumulation section in the treatment tank and passes through the bottom discharge port of the reaction tank. Pressurized 圧焙 sintered reaction vessel torrefied biomass is discharged.

Description

Related applications

  This application claims priority to US Provisional Patent Application No. 61 / 502,116, filed June 28, 2011, and US Provisional Patent Application No. 61/501, filed June 28, 2011. , 900. All of these applications are incorporated herein by reference.

Background of the Invention

  The present invention relates to a method for the roasting of biomass materials, such as, for example, lignocellulosic materials containing wood and other biomass, and in particular to a pressure reactor for the roasting of such materials.

  Roasting is used to convert biomass, such as wood, into an efficient fuel that has an increased energy density relative to the input biomass. For example, wood generally contains hemicellulose, cellulose and lignin. Roasting removes organic volatile components from the wood. Roasting can also depolymerize the long polysaccharide chains of the hemicellulose portion of the biomass to produce a hydrophobic solid combustible fuel product with increased energy density and improved grindability (on a mass basis). Since roasting changes the chemical structure of the biomass, the roasted biomass can be burned in coal-fired equipment (roasted wood or biomass has properties similar to low-grade coal) and high It is possible to compress into grade fuel pellets.

  Roasting is typically a relatively low temperature of 200 ° C. to 400 ° C., or 200 ° C. to 350 ° C. in an oxygen-deficient atmosphere, or a temperature outside the range used for a process known as pyrolysis. Is heat-treated. An oxygen deficient atmosphere contains a lower percentage of oxygen compared to the percentage of oxygen in atmospheric air. The roasting process is described in the related US provisional patent application 61 / 235,114.

  Non-pressurized reactors with multiple trays have been used for roasting, as described in US 2010/0083530 ('530 application). The '530 application states that roasting should take place in a reaction vessel operating at atmospheric pressure. By stating that it is advantageous to operate the reactor at atmospheric pressure, the '530 application teaches that the reactor should not be operated at pressures above atmospheric pressure. See paragraph [0061] of the '530 application.

  Pressurized reactors with multiple trays have been used in pulp mills to delignify pulp by oxidation. Examples of pulping reactors having multiple trays are disclosed in U.S. Pat. No. 3,742,735 (the '735 patent) and U.S. Pat. No. 3,660,225 (the' 225 patent). A reaction vessel with multiple trays allows pulp to cascade in a reaction vessel through a vertically arranged tray. The tray allows the pulp to step down the reactor in individual batches. The oxygen rich environment in the pulping reactor promotes delignification and drifting of the pulp. The '735 and' 225 patents do not suggest using a pulping reactor having an oxygen-deficient environment for roasting wood or other biomass material.

BRIEF DESCRIPTION OF THE INVENTION

  The difficulty associated with non-pressurized reaction vessels is that large volumes of gas need to be handled to conduct a given amount of heat to the material to be baked, resulting in a large reaction vessel. The mass of gas per unit volume at atmospheric pressure is substantially less than the mass of gas per unit volume at a substantial pressure, for example, greater than 20 bar gauge (290 psig). The volumetric flow rate affects the pressure drop in the bed of material, pipes, heat exchangers, larger equipment and higher energy to achieve the same heating efficiency. Requires consumption.

  Pressurizing the gas increases the mass of the gas for a given volume flow. Compared to non-pressurized tanks, pressurized reaction tanks have a smaller volume due to the use of compressed gas. The ability of a gas to conduct heat to biomass is proportional to the mass of the gas. If the mass of the gas is larger, the gas can heat the biomass faster.

  As is well known in the art, pressurized reactors require seals and other equipment to maintain the gases and materials in the reactor under pressure. Similarly, a pressure transfer device is required at the inlet to the pressurized reaction vessel or in the supply system for the pressurized reaction vessel to pressurize the material being supplied to the reaction vessel. Furthermore, the pressurized reactor requires a pressurized gas and a conduit for the pressurized gas.

  A new reaction vessel for the roasting of biomass material was invented, which uses an oxygen-deficient hot gas under substantial pressure to create vertically stacked trays for drying and heating biomass. Have. Stacked trays provide a moving bed of biomass in a relatively compact vertical reactor. Furthermore, the reaction vessel is substantially smaller than the reaction vessel for roasting performed at atmospheric pressure. An oxygen-deficient pressurized gas circulates in the reaction vessel and in a pressurized conduit that reheats the gas.

  The reaction vessel uniformly heats each tray so that the material being roasted is uniformly heated at each height in the reaction vessel. In order to achieve uniform heating of the material on each tray, the flow of oxygen-deficient gas through the material bed on each tray is from 1 to 1 per kilogram (kg) of dry material being processed on the tray. Controlled to a range of 6 kilograms of gas. The flow rate of the oxygen-deficient gas relative to the dry material through the material bed on each tray may be in other ranges, for example in the range of 1-3.

  The flow of oxygen-deficient gas through each of the trays may be continuous. An oxygen-deficient gas need not be completely devoid of oxygen. A gas is a heat transfer medium that adds heat to or removes heat from a material that is undergoing roasting. The gas flows through the material and the tray. A continuous flow of oxygen-deficient gas through the material in the tray heats the material if the gas is at a higher temperature than the material. The constant flow of gas cools the material when the roasting reaction, which is an exothermic reaction, makes the material hotter than the gas. If the material is overheated, the roasting reaction is overreacted, so the continuous flow of gas is controlled so that the temperature of the material in each tray is about the same temperature as the gas.

  Biomass material can have a total retention time of 15-60 minutes for all of the trays in the reaction vessel. This holding time includes the time in the tray where the material undergoes roasting and the time in the lower tray where the material is cooled after the roasting reaction. The retention time in the reaction vessel can be selected based on the material being processed in the reaction vessel. For example, the total holding time in the reaction vessel is 15 to 25 minutes for a lignocellulosic material such as wood.

  Each tray has a pie-segment shaped opening from which biomass material falls into the tray at the next lower height in the reactor. The biomass material travels in the reaction vessel, moves on the tray, and then falls through the opening. A scraper slides the material on the tray toward the opening. The rotation speed of the scraper is selected to provide the desired holding time on each tray. The holding time can be uniform for each tray in the reaction vessel. The holding time is selected based on the number of trays each performing drying, roasting and (optional) cooling of the biomass and the time required to perform each of these processes.

A method for roasting biomass using a roasting reaction vessel with stacked trays was invented, which method comprises:
Supplying biomass to the upper inlet of the reactor and depositing the biomass material on the upper tray in vertically stacked trays in the reactor;
Heating and drying the biomass material with oxygen-deficient gas injected into the reaction vessel under a pressure of 3-20 bar as the biomass travels on each of the stacked trays around the reaction vessel;
Dropping the biomass stepwise down through the tray by passing the biomass through an opening in each of the trays and depositing it in the lower tray;
Discharging the roasted biomass from the lower outlet of the roasting reaction tank;
Circulating the extracted gas from the lower height of the reaction vessel and supplying this gas to the upper region of the reaction vessel.

  Oxygen-deficient gases include superheated water vapor, nitrogen and other non-oxygen gases, or low oxygen gases suitable for the purposes of this invention. The biomass can be pressurized with a pressure transfer device before being fed to the reaction vessel. The tray is a mesh, screen, or has holes or slots, and heating and drying of the biomass includes passing gas through the biomass and tray. The scraper device rotates to move the biomass material across the tray in an arcuate path. Alternatively, the scraper device and biomass do not rotate around the reaction vessel, but the tray may rotate. Each tray opening may be a triangular shaped portion extending from the shaft in the reaction vessel to the wall of the reaction vessel.

  The gas is injected into the reaction vessel at multiple heights, but this gas is hotter when injected at the lower height than when injected at the upper height. Below the height of the reaction vessel from which the gas is extracted, the biomass continues to drop down through the tray.

A method for the roasting of lignocellulosic biomass using a roasting reactor with stacked tray assemblies was invented, the method comprising:
Continuously supplying biomass to the upper inlet to the roasting reactor and depositing the biomass material on the upper tray assembly in a plurality of tray assemblies stacked vertically in the reactor;
When the biomass moves through the reaction vessel while being supported by the trays of the respective tray assemblies, there is no substantial oxidative effect on the biomass injected into the reaction vessel and at least under a pressure of at least 3 bar gauge Heating and drying the biomass with a gas having a temperature in the range of 200 ° C to 250 ° C;
Dropping the biomass stepwise down through the tray by passing the biomass through an opening in each of the trays and depositing it on the tray of the next lower tray assembly;
It includes a step of discharging the roasted biomass from the lower outlet of the roasting reaction tank, circulating the gas extracted from the reaction tank, and returning it to the reaction tank.

  The tray of each tray assembly has a mesh, screen, or holes, and heating and drying the biomass includes passing gas through the biomass and tray. The holes or openings in the tray assembly are covered by a fine mesh or screen material rather than the material used to form the tray assembly. The gas entering each tray assembly passes through a pipe that is substantially at the same height as the extraction pipe that extracts the gas from directly above the tray assembly. In addition, each tray assembly includes a rotating scraper device above the tray and an extraction gas chamber below the tray.

  The gas injected into the tray assembly for roasting is at a higher temperature, eg, 5-60 ° C., than the gas injected into the tray assembly for drying or cooling. Furthermore, the space space under all tray assemblies and at the bottom of the reaction vessel is the zone where biomass forms deposits. The space space may be used to complete the roasting of the biomass and cool the roasted biomass before the biomass is discharged from the reaction vessel. The cooling gas injected into the cooling zone is cooler than the gas injected into the cooling tray assembly, the cooling zone cools below the temperature at which biomass automatically burns when exposed to the atmosphere, and the cooling tray The assembly cools the roasted biomass to stop or inhibit the roasting reaction. The gas flow in space can be co-current or counter-current to the biomass material flow.

  The gas extracted from the tray assembly and cooling zone may be circulated to the reaction vessel by a blower or compressor. The gas to be circulated may be passed through a cyclone, condenser or filter to separate particles and condensable by-products before the gas enters the compressor or blower. The gas circulated to the roasting tray assembly may be heated before being injected into the roasting tray assembly. A portion of the gas extracted from the tray assembly may be directed to a combustion device or other process step to produce thermal energy that is added to the gas circulated to the roasting tray assembly.

A pressure roasting reaction tank was invented, the reaction tank extending substantially vertically;
A rotatable shaft extending vertically down through the top of the reaction vessel;
A plurality of scraper devices, each at a different height in the reaction vessel, coaxial with the shaft;
A plurality of tray assemblies, each tray assembly being associated with one of the scraper devices, whereby the scraper device is directly above the tray assembly tray;
A plurality of gas extraction openings in the vessel wall;
Including a bottom discharge port of the reaction vessel through which the roasted biomass is discharged,
At least one of the tray assemblies includes a tray, a gas extraction passage below the tray, and a gas injection passage above the tray, the tray being an open mesh or allowing gas flow to pass through the tray. Is impermeable to the passage of biomass,
Each of the trays includes a discharge opening for conveying biomass from the tray to one tray at the bottom of the tray assembly;
The discharge opening in the lowermost tray conveys the biomass to the biomass deposit in the treatment tank,
At least one of the gas extraction openings is aligned with a gas extraction passage, and another one of the gas extraction openings is at a height below the bottom tray assembly and above the biomass deposit. It is a feature.

  FIG. 1 is a perspective view of the front and top of a pressurized reaction treatment tank with the front wall of the reaction tank removed to allow illustration of the internal components of the reaction tank.

  FIG. 2 is a perspective view of the front and bottom of a pressurized reaction treatment tank with the front wall of the reaction tank removed to allow the internal components of the reaction tank to be illustrated.

  FIG. 3 is a perspective view of the lower region of the pressurized reaction treatment tank showing the support leg and the bottom outlet of the reaction tank and showing the converging portion inside the reaction tank.

  FIG. 4 is a view from the bottom to the top of the pressurized reaction treatment tank.

  FIG. 5 is a side view of the pressurized reaction treatment tank with a quarter of the reaction tank removed for purposes of illustration.

  FIG. 6 is a perspective view of the top and sides of the pressurized reaction vessel, with a quarter portion of the reactor removed for purposes of illustration.

  FIG. 7 is an enlarged cross-sectional view of a portion of a pressurized reaction vessel illustrating a portion of the tray assembly.

  FIG. 8 is a perspective view of the open top of the pressure treatment tank, with the reaction vessel outer wall removed to illustrate the components of the tray assembly.

  FIG. 9 is a view from the top to the bottom of the open top of the pressure treatment tank.

  FIG. 10 is a cross-sectional view of a portion of a pressure treatment vessel illustrating a vertical shaft and a lower support for the shaft.

  FIG. 11 is a perspective view of the spoke wheel scraper component of the tray assembly.

  FIG. 11A is a schematic view of an enlarged portion of one lower edge of a spoke or blade 60 of a scraper device.

  FIG. 12 is a perspective view of the tray and bottom plate of the tray assembly.

  FIG. 13 is a perspective view of a converging portion of the pressurized reaction tank.

  FIG. 14 is an enlarged view of the convergence portion to show a screen that allows gas to be extracted from the convergence portion.

  FIG. 15 is a schematic view of a tray assembly for showing the gas flowing into and out of the biomass on the tray.

  FIG. 15A is an enlarged view of a cross section of the tray to show exemplary slots, holes or openings in the tray.

  16-18 are process flow schematic diagrams illustrating an exemplary roasting process using a pressurized reaction vessel.

Detailed Description of the Invention

  1 and 2 show a pressurized processing vessel 10 for receiving, processing, drying and cooling biomass material from a biomass supply 12 through an upper inlet 14. Biomass is wood chips, wood pulp or other comminuted cellulosic materials. While traveling over a series of upper drying tray assemblies 16 in the reaction vessel, the biomass is dried. In addition or alternatively, the biomass may be dried before being introduced into the reaction vessel 10.

  The upper inlet 14 to the pressurized tank is connected to a continuous supply, pressure isolation device, such as a conventional rotary valve or plug screw feeder, to supply biomass from a biomass source at atmospheric pressure to the pressurized tank. The pressurized tank 10 is operated in a gas phase in which dried biomass is in a dry state in the reaction tank.

  Biomass is supplied to the inlet 14 at ambient temperature, but if the dryer 21 preheats the biomass, the biomass will be at a temperature between 80 ° C. and 120 ° C. or higher before entering the reactor. Biomass is pressurized and heated by the hot oxygen-reduced gas or oxygen-deficient gas in the reaction vessel. The gas entering the reaction vessel is at a temperature in the range of 200 ° C. to 600 ° C., in particular in any of the ranges of 250 ° C. to 400 ° C., 250 ° C. to 300 ° C. and 300 ° C. to 380 ° C.

  Biomass enters the pressure treatment vessel 10 through the upper inlet 14, which is at the top or upper portion of the reaction vessel and is a single inlet orifice or a row of inlet orifices. The biomass may be pre-dried before entering the reaction vessel or may be dried in any drying zone (tray) 15 in the upper region of the reaction vessel. Under the drying zone, the biomass enters the roasting zone 41 (the tray and optionally the chamber below the tray).

  Immediately below the upper inlet in the reaction vessel 10 is a chute that receives biomass from the inlet and directs it to a portion of the trailing section of the upper tray of the drying tray assembly 16. The trailing section is adjacent to the discharge opening 64 (FIG. 12) in the upper tray. Biomass falls into the trailing section of the tray and travels in an arc-shaped path across the tray until the biomass passes through the tray across the leading edge of the opening and falls into the trailing section of the next lower tray To do. The trailing section is the area of the tray farthest from the opening in the tray with respect to the biomass path on the tray. Depositing biomass on the trailing section of the tray ensures that the biomass entering the treatment tank is retained on the upper tray during almost the entire rotation of the tray.

  The open portion 64 (also referred to as “opening”) of each tray is preferably not vertically aligned with the opening 64 in the tray directly above or below the tray. If the opening is vertically aligned, the biomass will immediately fall from one open part through the open part in the underlying tray without stagnation on the support surface of the underlying tray.

  The opening portions 64 are vertically displaced so that each opening is on the trailing area of the upper portion of the tray directly below the opening. The trailing area of the tray is adjacent to and behind the open portion in the direction of rotation of the scraper device 56. By aligning the open portion 64 above the trailing area on the lower tray, the biomass falls through the open portion onto the trailing area. As the scraper rotates, the biomass slides across the entire upper surface of the tray in an arc-shaped path from the trailing area to the opening. Holding the biomass on the upper surface of each tray maximizes the retention time of the biomass on the tray, whereby the biomass is heated (dried in the upper tray), dried, and roasted (in the lower tray). .

  Directly beneath one or more optional drying tray assemblies 16, one or more roasting tray assemblies 18 are disposed, and the biomass material dried on the assemblies is subjected to conditions that cause a roasting reaction. Under the roasting tray assembly, one or more optional cooling tray assemblies 20 are disposed. The structure of each of the tray assemblies 16, 18, and 20 is substantially similar. Each tray assembly is advantageously a moving bed where the biomass is exposed to a stream of oxygen-deficient gas.

  The inflow of heated gas into the pressure reactor, the flow in the pressure reactor and the outflow from the pressure reactor are at the top of the reactor where the biomass is heated to the desired temperature for roasting. It is configured to facilitate the flow of hot, pressurized gas through the tray assembly. As shown in FIG. 1, hot oxygen-depleted gas passes through a top inlet manifold 86 and gas injection nozzles 34 located at various heights of tray assemblies 16, 18 and 20 in the upper portion of the reaction vessel. It is injected into the upper part of the reaction vessel 10.

  The oxygen-deficient gases flowing at multiple heights in the reaction vessel can be at different temperatures and compositions for each of the tray assemblies. For example, the hot gas 86 introduced into the uppermost part of the reaction tank is a temperature slightly higher than the temperature of the dry biomass 12 supplied to the reaction tank, for example, 100 ° C., and is higher by, for example, 10 ° C. to 40 ° C. The hot gas introduced at the subsequent lower height of the reaction vessel is progressively higher and slightly higher than the temperature of the biomass in the reaction vessel (approximate to the injected hot gas). By injecting the gas at a temperature just above the biomass being heated by the hot gas, the efficiency of the heating is injected at a single temperature that is substantially higher than the biomass entering the reactor. Increased compared to Alternatively, the gas injected for drying and roasting may be of substantially similar temperature and composition, and the gas for cooling the biomass is from other cooler heights in the reactor. The extracted gas may be used. For example, the exhaust gas from the drying tray is cooler than the gas from the roasting level and below the temperature required for roasting.

  The number of tray assemblies for drying, roasting and cooling depends on various factors, which are used by any drying device 21 to dry the biomass before the material enters the reaction vessel 10. Whether or not the roasting and cooling zones 22, 24 or the cooling screw 68 (FIG. 16) can cool the biomass from the temperature at which the roasting reaction takes place to a lower temperature at which the roasting is stopped.

  As an example, the total number of tray assemblies is a number (N) and can range from 5-15. The number of drying tray assemblies (DTA) 16 is zero, 1 (as shown in FIG. 16), or is determined based on the following algorithm.

DTA = N ^* L (L is in the range of 0.2 to 0.3.)

  The number of cooling tray assemblies (CTA) 20, if any, is 2 as shown in FIG. 16 or is determined based on the following algorithm.

CTA = N- (N ^* M) (M is in the range of 0.7 to 0.8.)

  The number of roasting tray assemblies (TTAs) 16 is greater than each of DTA and CTA, for example four TTAs as shown in FIG. 16, or is determined based on the following algorithm.

TTA = ((N ^* L) +1)-((N ^* M) -1)

  The number of tray assemblies in the reaction vessel and the ratio of drying, roasting and cooling tray assemblies depends on the design requirements for the reaction vessel. For example, the total number of tray assemblies in the reaction vessel 10 is either in the range of 4-20 or in the range of 6-15. The ratio of the drying tray assembly to the cooling tray assembly ranges from 15 to 30 percent (%) of the total number of tray assemblies. The ratio of tray assemblies for roasting ranges from 70 to 40% of the total number of tray assemblies. These ranges are exemplary and do not prescribe limits on the number of tray assemblies. For example, the reaction vessel may not have a drying tray assembly and a cooling tray assembly, but may all have a tray assembly for roasting.

  The roasting reaction may occur in the intermediate tray assembly. The range of intermediate tray assemblies where roasting occurs is any of 15-85%, 30-60% and 15-100% of the total number of tray assemblies. If roasting occurs in most or all of the tray assemblies, biomass drying may occur completely or partially outside the reactor or in a dryer upstream of the reactor, and any cooling may be It may occur in the accumulation of roasted biomass in the lower region or in the cooling screw near the reactor discharge.

  Inlet nozzles and extraction nozzles are numbered in FIG. 16 according to their corresponding tray assemblies. The top tray assembly 16 receives hot oxygen-depleted gas from the top inlet 86, while the top inlet receives gas from the heat exchanger 84 or gas extracted from the cooling tray assembly or zone of the reaction vessel 10. .

  A lignocellulosic material that has been chipped or cut to have a chip size of, for example, a length of 10-50 millimeters (mm), a width of 10-50 mm, and a thickness of 5-20 mm is provided from the biomass supply 12. The The thickness of the chip may be in other ranges, for example 20-30 mm, 15-25 mm and 3-10 mm. These chip dimensions are most suitable for wood. Other chip dimensions may be suitable depending on the type of wood or non-wood used for the biomass.

  Under the stack of tray assemblies 16, 18 and 20, the pressure vessel 10 has a roasting zone 22 and an optional lower cooling zone 24. The roasting zone 22 and the lower cooling zone 24 are hollow areas under the lowermost tray 20 of the pressure reactor and may span one half or two thirds below the height of the pressure vessel. The pressure tank has a predetermined dimension, for example, a diameter and a height, based on desired operating conditions, for example, the composition of the biomass material and the volume ratio of the biomass flowing through the reaction tank. In general, in an industrial scale unit, the pressure vessel has a height, for example, greater than 100 feet (33 meters) and a diameter greater than 9 feet (3 meters).

  The lower cooling zone 24 of the pressure reactor may include a convergence section, such as a one-dimensional convergence, to provide uniform movement of biomass through the bottom of the reactor and to the bottom discharge port 26. is there. The converging part is sold by Andritz Group and is described in U.S. Pat. Nos. 5,500,083, 5,617,975, 5,628,873, “Diamond Back”. The convergence part of (DIAMONDBACK) (registered trademark) may be used.

  The lower zone 24 of the pressure reactor is maintained at a lower temperature than the tray assembly used for roasting. The lower zone 24 contains deposits of roasted biomass material that have been processed in the tray assembly and lowered into the lower zone.

  The temperature in the lower zone 24 is 265 ° C. or lower, 240 ° C. or lower, or 200 ° C. or lower, and with or instead, the temperature in the lower zone 24 is at least 15 ° C. higher than the maximum temperature of the hot gas entering the roasting tray assembly. ~ 40 ° C lower. In order to control and maintain the temperature in the lower zone, a cooling gas is injected into the upper part of the lower zone, for example via injection nozzle 92 (FIG. 16), into the cooling gas and the downward flow of biomass through the reactor. Provides co-current flow. It may be desirable for these gases to flow countercurrent to the biomass flow, replacing the hot contaminated gas that enters with the biomass toward the top of the deposit. Alternatively, cooling gas may be injected through the nozzle 94 into the bottom portion of the lower region, which may be part of a central pipe that extends upward and axially through the reaction vessel. The cooling gas flowing in through the nozzle 94 flows cross-currently with respect to the biomass flow. In addition, the cooling gas nozzle 94 is arranged to provide a back-flow gas flow through the reaction vessel so that gas is injected on one side of the reaction vessel and extracted on the opposite side of the reaction vessel. Cooling gas injection and extraction occurs at several heights in the lower zone 24. The temperature of the cooling gas injected into the cooling tray assembly and cooling zone is adjusted so that cooler cooling gas flows into the lower height of the reaction vessel. The roasted biomass material should be at a temperature below the temperature at which it is autocombusted at the bottom of the reactor or at least when passing through the pressure transition device before the biomass is exposed to the atmosphere. It is.

  As shown in FIGS. 3 and 4, the pressure reaction tank is supported by a support leg 28 extending vertically between the reaction tank and the ground. The support leg lifts the bottom of the reaction tank, and the discharge device It is possible to attach to the discharge port 26 under the reaction vessel. Alternative support structures include a skirt-like arrangement or use of support rings installed at several midpoints in the reaction vessel above the “DIAMONDBACK®” converging section. Such a support ring is attached to the building structure in some suitable manner.

  The pressure vessel 10 may have an access and observation port 30, which provides access to the pressure vessel cooling and convergence zones when opened. Access and observation ports are generally closed during operation of the pressure vessel. The observation port includes a transparent window to allow observation inside the pressure vessel. Other observation ports with transparent windows or sight glass may be installed in the pressure vessel at locations other than the access and observation port 30.

  FIG. 5 is a cross-sectional view of the pressure treatment tank 10. The vertical shaft 32 is coaxial with the processing tank and extends at least through the tray assemblies 16, 18 and 20 in the processing tank. An upper portion of the shaft 32 extends from the top of the processing tank and is driven to rotate by a motor and gear assembly 33, which is fixed to the top of the processing tank for torsional support. The lower end of the shaft 32 is supported by a bearing and bracket assembly 35 below the lowermost tray in the processing bath. Similarly, the upper end of the shaft is supported by a bearing at the top of the processing bath and is connected to the gear and motor assembly. A spadone journal 37 rotatably couples the shaft 32 with the bearing and bracket assembly 35.

  FIG. 6 is a perspective view of the top and sides of the processing bath 10 with a quarter portion of the processing bath removed for purposes of illustration. The shaft 32 extends above the top of the processing bath. A spline on the top end of the shaft is adapted to the motor and gear assembly. A top plate 38 (FIG. 5) seals the top of the processing bath and provides support for the shaft bearings, motor and gear assembly 33.

  6-12 illustrate the construction and operation of the tray assemblies 16, 18 and 20. FIG. Each of the tray assemblies 16, 18 and 20 is porous, screened, meshed or other structure to allow gas to pass through the tray and block the passage of biomass material such as fibers. A horizontal tray 40 is included. The tray 40 is annular and extends in a radial direction from the shaft 32 to the inner surface of the cylindrical wall of the processing bath 10. The tray is horizontal and is generally at the same level. The tray is fixed to the processing tank and does not rotate with the shaft. For example, the tray is a porous steel mesh that is arranged horizontally and substantially covers the open area in the processing tank between the shaft 32 and the wall 42 of the processing tank. Other materials used to form the tray 40 include steel plates made porous by drilled or laser cut openings, slots or holes.

  FIG. 15A is an enlarged view of a cross section of the tray to show exemplary slots, holes or openings 100 in the tray. As biomass travels over the surface of the tray in the direction of flow arrow 102, the gas passes through the biomass and flows down through an opening to gas passage 52 below the tray. The slot, hole or opening has a generally uniform cross section through the tray. Alternatively, as shown in FIG. 15A, the slot, hole or opening 100 has an upper portion 104 that is generally uniform in cross-section and a lower portion 106 that expands downward in cross-sectional area. The upper portion of the slot, hole or opening 100 is 30-50 percent of the thickness of the tray. Further, the upper edge of the slot, hole or opening is a beveled portion 108 at the trailing edge, for example as shown in FIG. 15A. The ramp 108 helps to prevent fibers from the biomass from being captured on the upper edge of the slot, hole or opening, and in particular to avoid being captured on the trailing edge of the edge. The slot, hole or opening may be covered with a finer mesh or screen material.

  Directly below the tray 40 is a solid annular bottom plate 44 that forms the bottom for the gas passage 52 between the tray 40 and the plate 44. This gas passage is for biomass and gas drawn through the tray and exhausted to the extraction nozzle 36, which corresponds to the gas passage between the tray and the bottom plate 44. At a height, it is attached to the wall 42 of the treatment tank. Baffle plates 46, 48 and 50 are mounted on the bottom plate 44 and extend upwardly through the gas passages to the tray 40. The baffle plate directs the gas toward the inlet to the extraction nozzle 36. The baffle plate may include a radially extending short baffle plate 46 and a long baffle plate 48 and an annular wall plate 50 that forms an end wall for the gas passage. A long radius plate 48 divides the gas passage into triangular screen segments. As an example, each tray may have 4-8 screen segments. In addition to the tray 40 formed of pie-shaped segments, the plate 44 may also be pie-shaped segments, and the long radius plate 48 may form sidewalls for each of these segments.

  The baffle plate also provides support for the screen or grid of tray 40. The toroidal wall plate has an open slot that allows gas to flow to the inlet to the extraction nozzle 36 and the pipe for the injection nozzle 34 connects the bottom plate 44 from the wall of the process vessel. Allowing it to pass through and open to the next lower tray assembly.

  The tray 40 is supported by the inner surface of the wall 42 of the pressure treatment tank 10. Wall 42 includes hangers, ridges, or other support surfaces on which the outer rim of each tray rests. By opening the processing tank and sliding the tray into or out of the processing tank, the tray may be removed, replaced, or rearranged in the processing tank.

  Alternatively, the tray, rotating scraper and shaft are built as a cartridge assembly and are supported primarily from the top head plate of the processing tank. The cartridge assembly as a whole can be inserted into the processing bath and removed from the processing bath. The anti-rotation tip or piece is attached to the wall of the processing tank for the purpose of preventing the cartridge assembly from rotating in the processing tank.

  Biomass flowing through the chute 116 falls to an optional lower portion 80 of the treatment tank. Biomass forms deposits in the lower portion that temporarily holds the biomass. Biomass continues to undergo a roasting reaction in the sediment. The roasted biomass is discharged from the outlet 116.

  As an alternative to a rotating scraper device, the tray may rotate with the shaft. The stationary scraper device is in a fixed position and includes a radial arm that extends over the tray.

  The injection nozzle 34 has an outlet 53 extending through the gas passage and extending through the bottom plate 44. The outlet 53 discharges gas into a biomass passageway 54 formed between the bottom plate 44 of one tray assembly and the tray 40 of the tray assembly directly below the bottom plate. The biomass passage is a volume in the processing tank 10 that receives biomass. The number of injection nozzles 34 for each tray is uniform and is selected based on the operating conditions of the processing bath. Selection of the number of nozzles is sufficient as long as it provides a uniform gas flow through the biomass material on the tray with uniform flow distribution and uniform gas temperature. For example, 6-8 injection nozzles are used to provide a uniform flow for each tray.

  The injection nozzle 34 is configured to supply 1-4 kilograms of gas per kilogram (kg) of biomass on the tray. The volume of gas supplied by the injection nozzle is in the range of 1-6 kg, 1-12 kg or 1-24 kg per kilogram of biomass.

  The injection nozzle is assembled with the tray 40, bottom plate 44 and baffle plates 46, 48, 50. For example, each pie-shaped segment consisting of a tray, a bottom plate, a baffle plate, and an injection nozzle is pre-assembled and mounted on a support structure, such as a radial spoke, in a processing bath. In addition, these pre-assembled tray assembly segments or pre-assembled tray assemblies remove the top plate 38 and lower the pre-assembled assembly to the appropriate height of the processing tank in which the assembly is to be placed. In some cases, it may be installed in the reaction vessel. Once placed, the injection nozzle is connected to a nozzle opening in the side wall 42 of the process bath. Similarly, when the tray assembly is placed in the reaction vessel, the opening in the outer baffle plate 50 is aligned with the extraction nozzle 36 attached to the side wall 42 of the treatment vessel.

  Below each tray is one or more gas extraction nozzles disposed at substantially the same height on the outer wall of the processing tank and spaced at a uniform angle around the processing tank. The number of gas extraction nozzles is the same as or different from the gas injection nozzles. For example, one, two, or three gas extraction nozzles may exist under each tray, or one gas extraction nozzle may exist for each tray segment. The gas injection nozzle 34 may be smaller in diameter than the gas extraction nozzle, especially if the oxygen-deficient gas expands when entering the treatment tank. The gas inlet manifold for the nozzles 34, 36 is a thick wall pipe or made of steel. For each tray, gas enters the treatment tank through gas injection nozzle 34, passes through the biomass material and tray on the tray, and is discharged from the treatment tank through extraction nozzle 36.

  FIG. 11 shows a scraper device 56 that moves the biomass through the biomass passages of each tray assembly. The scraper device 56 has a radius scraper spoke or blade 60, a center collar 58 and an outer annular ring 56. The ring 56 is proximate to the wall 42 of the processing bath 10 and is, for example, within 3 to 5 millimeters (mm) of the wall 42. The lower edge of the blade 60 is close to the upper surface of the tray, for example within 3-10 mm of the tray. The top edge of the blade is adjacent to the bottom plate 44 of the next height tray assembly, for example within 10-25 mm. The scraper device spoke or blade 60 extends straight and is aligned with a radial line extending between the collar and the ring. Alternatively, the spokes or blades 60 are inclined in the direction of the angle of rotation (as shown in FIG. 11) at an angle of 15-20 degrees with respect to the radial line, and the blades are curved in the direction of the angle of rotation. Or curved.

  FIG. 11A is a schematic view of an enlarged portion of one lower edge of a spoke or blade of a scraper device. A slot, pipe or other gas passage 112 is disposed at the lower edge and has an opening or nozzle 114 disposed along the radial length of the passage 112. A high pressure gas supply 114 is connected to the passage 112 through the shaft 32 of the processing bath. The high pressure gas source 114 is external to the processing bath and is shown in the shaft in FIG. 11A for illustration purposes only. The high pressure gas flowing through the passage 112 and the nozzle 114 is applied to clean the opening 100 in the tray and ensure that the gas passes freely through the opening. Alternatively, the high pressure gas source 114 may be a suction source such as an air pump or blower. Suction applied to the passage 112 and the nozzle 114 removes fibers and debris from the openings. When the blade having the passage 112 rotates on the tray, the opening 100 in the tray is cleaned. The cleaning of the opening in the tray may be performed simultaneously with the processing of the biomass in the processing tank 10.

  The scraper device 56 is pre-assembled and attached by sliding the device down in the processing bath. The center collar is welded or otherwise attached to the shaft. The diameter of the scraper bar matches the internal diameter of the treatment tank with a small gap. The center collar is fixed to the shaft 32 so that the scraper device rotates with the shaft. The height of the scraper device 56 is approximately the same as the height of the biomass space 54, as shown in FIG. 15, or approximately the desired thickness of the biomass 66 on the tray.

  The rotation of the shaft 32 rotates the scraper device 56 immediately above each tray 40. Biomass fills or partially fills the volume between the spokes 60 of the scraper device. The rotation of the scraper device on each tray moves the biomass material across the tray. As the biomass material moves across the tray, the biomass material is exposed to a constant flow of oxygen-deficient gas at a uniform temperature. The gas enters the processing tank through a gas injection nozzle 34 having an opening in the outer wall of the processing tank or through an opening 53 in the bottom plate 44 above the tray and biomass space 54. The opening 53 in the bottom plate is a single exhaust port or a gas distribution manifold 55 with a series of gas exhaust ports located above the biomass on the tray. Also, the opening 53 may be enlarged to facilitate the disbursing of oxygen-deficient gas onto the biomass on the tray. The gas distribution manifold 53 is configured by arranging pipes and pipe connecting portions having nozzles, and is assembled together with the tray assembly. Openings or gas distribution manifolds are arranged to distribute gas evenly to the biomass on the entire tray. In order to achieve a uniform gas distribution, a plurality of injection nozzles are arranged around the wall of the processing tank, for example at least one nozzle is arranged for each tray segment.

  As the gas moves through the biomass and tray, the scraper device rotates to move the biomass in an arcuate path through the tray assembly. Biomass travels through the tray assembly and is discharged through the opening 64 shown in FIG. The openings include chutes, ducts, pivoting doors or other discharge devices in the tray. Biomass descends through openings 64 into the scraper device and onto the tray of the next lower tray assembly. The opening 64 is aligned perpendicular to the opening 64 in the next lower tray assembly so that the biomass is in the triangular portion of the scraper device that is just rotating over the chute in the next lower tray assembly. Fall. These chute alignments allow the biomass to move in an arc over the entire tray, maximizing the biomass retention time in each of the tray assemblies. The bottom tray may be an inverted conical shape with a center discharge chute that allows biomass to flow to the vertical center of the cooling zone.

  13 and 14 show the convergence zone 24 in the bottom portion of the processing bath 10. The converging portion includes a region that converges only in one dimension, and has, for example, converging flat side walls and non-converging curved walls that join these side walls. The one-dimensional converging portion reduces the tendency for the biomass material to adhere in the treatment tank while flowing to the outlet 26. The one-dimensional convergent part is marketed by the Andritz Group as “Diamondback®”. One-dimensional convergence generally eliminates the need to have a rotating scraper and other mechanical devices to prevent biomass blockage at the bottom of the treatment tank. Although a one-dimensional converging portion has been disclosed herein, other means of conveying material to the discharge point at the bottom of the processing tank may be used, such as a motor-driven movable bottom unit, such as a scraper or outlet device assembly. Good.

  FIG. 15 is a schematic view of gas flow through the tray assembly. The gas flows through a gas injection nozzle 34 that passes in alignment with the gas passage 52 directly above the tray assembly. The injected oxygen-deficient gas flows through outlet 53 and flows into biomass space 54 in the tray assembly. There may be a number of injection nozzles 34 having outlets 53 arranged radially around the biomass space for each tray assembly. The gas stream is uniformly distributed to the upper surface of the biomass bed 66 by entering the gas space of the biomass space 54 above the biomass bed 66. The thickness of the biomass bed is, by way of example, 1 meter (1 m) or other thickness that achieves the desired biomass throughput and allows the heating gas to flow uniformly through the biomass bed. . For example, the thickness of the biomass bed ranges from 150 millimeters to 1 meter or exceeds 1 meter. The biomass bed is placed on the tray 40.

  The gas flows down to the biomass bed and tray and enters the gas passageway 52. The gas exits the gas passages through extraction nozzles 36 that are arranged radially around the wall of the treatment tank in each segment of the tray. A gas extraction nozzle 36 is arranged to facilitate a uniform flow of gas through the biomass on the tray. The number of gas extraction nozzles is less than the number of gas injection nozzles 34.

  FIG. 15A is an enlarged view of a cross section of the tray to show exemplary slots, holes or openings in the tray (the finer mesh or finer screen material used to cover the holes, slots or openings is illustrated. It has not been). As biomass travels on the surface of the tray in the direction of flow arrow 102, the gas flows through the biomass and openings and flows down to gas passage 53 below the tray. The slot, hole or opening has a generally uniform cross section through the tray. Alternatively, as shown in FIG. 15A, the hole, slot or opening 100 has an upper portion 104 that is generally uniform in cross section and a lower portion 106 that expands downward in cross sectional area. The upper portion of the slot, hole or opening 100 is 30-50 percent of the thickness of the tray. Further, the upper edge of the slot, hole or opening is a sloped portion 108, such as at the trailing edge as shown in FIG. 15A. The ramp 108 helps to prevent fibers from the biomass from being captured on the upper edge of the slot, hole or opening, and in particular to prevent it from being captured on the trailing edge of the edge. .

  16 to 18 are process flowcharts showing an exemplary roasting process performed in the processing tank 10. A common feature of these processes is that the roasted biomass material is cooled before being decompressed and exposed to the atmosphere. Cooling occurs in a pressurized cooling tip tube 67 and cooling screw 68 assembly downstream of the processing tank lower tray, cooling zone 24, or processing tank discharge 26. Alternatively, cooling can occur in a fluidized bed (not shown). It is also possible that zone 24 is a combined reaction zone before the cooling zone.

  Cooling gas is injected into the lower tray, cooling zone, tip tube or tip screw to cool the roasted biomass prior to discharge from the reaction vessel. The cooling gas is used to stop or slow the roasting reaction and to make the roasted biomass safe and appropriate for the oxygen atmosphere outside the treatment tank. For example, cooling to stop or slow down the roasting reaction occurs in the cooling zone 22 or a pressurized cooling device downstream of the treatment tank to make the biomass suitable for an oxygen atmosphere. Cooling to stop or slow the roasting reaction requires a cooling gas, which is 10-30 degrees Celsius below the gas injected into the roasting tray assembly to facilitate the roasting reaction. It is. The cooling gas to make the roasted biomass safe against oxygen atmosphere is further 10-30 degrees Celsius, 10-50 degrees Celsius, 10-80 degrees Celsius, 10 degrees Celsius from the cooling gas added to the cooling tray assembly. It is cooler by -100 degrees or 20-120 degrees Celsius.

  For example, the gas from the cooling zone 24 in the converging portion is discharged through the screen 65 on the side wall of the processing tank as shown in FIGS. 13 and 14. Similarly, the cooling gas is discharged from the lower cooling tray or from the tip tube and screw 68.

  The cooled and roasted biomass passes through a pressure transmission device 70 such as a rotary valve. The pressure of the roasted biomass downstream of the pressure transmission device is atmospheric pressure. From the pressure transmission device, the roasted biomass is transferred to another process, for example using a screw conveyor 72.

  In the treatment tank, for example, in the lower tray 18, the biomass is dried and heated at a temperature of 200 ° C. to 400 ° C. in an oxygen-deficient environment before the baking reaction occurs. The biomass may be dried and heated with a separate dryer acting on the biomass 12 before reaching the treatment tank 10. In addition or alternatively, the biomass may be dried in the upper drying zone of the treatment vessel 10 including one or more of the tray assemblies. The biomass may be directly heated with an oxygen-deficient gas, such as superheated steam, nitrogen or a mixture of both, injected into the top of the treatment tank or dryer.

  The volume of hot oxygen-deficient gas required in the treatment tank is dramatically reduced in the pressurized reaction tank 10 compared to a tank operating at atmospheric pressure. When the treatment tank 10 is pressurized, the volume of the hot gas required to heat the biomass is reduced by 2 to 35 times compared to the tank at atmospheric pressure. The reduction factor for the treatment tank depends on the pressure in the treatment tank.

  Since the volume of hot gas required in the pressurized reaction vessel is reduced, the volume of the treatment vessel 10, and thus the size and cost of the treatment vessel 10, is significantly reduced compared to a vessel operating at atmospheric pressure. The pressurized tank into which the hot gas is injected provides efficient and economical heat transfer from the gas to the biomass in the treatment tank.

  The treatment tank 10 is pressurized by injecting an oxygen-deficient gas, such as an oxygen-reduced gas, at a pressure up to 35 bar gauge (barg), for example, in the range of 3 bar gauge to 35 bar gauge. The pressurized tank 10 operates in an oxygen-deficient gas environment in which heated pressurized gas circulates through the tank in order to directly heat the biomass and promote a roasting reaction with the biomass.

  The hot oxygen-deficient gas is water vapor, such as superheated water vapor, nitrogen or carbon dioxide, and contains lower amounts of gaseous by-products from the roasting reaction. Further, hot gas is injected into the biomass in a supply system (not shown), for example at the inlet downstream of the pressure isolation device or the inlet downstream of the high pressure transmission device. If there is a high-pressure transmission device, no pressure isolation device is required at the inlet of the treatment tank 10.

  In the drying and roasting tray assembly, the hot gas flows through the biomass in the treatment bath 10 and directly heats the biomass to a temperature that promotes the roasting reaction in the material, for example in the range of 240 ° C to 300 ° C. The hot gas and the gas generated in the reaction vessel are discharged from the reaction vessel at various heights through the extraction nozzle 36. The gas is discharged from the reaction vessel at a temperature of about 250 ° C to 280 ° C. The gas used for drying is at a lower temperature than the gas used for roasting. The gas for drying is the gas extracted from the roasting tray assembly and is circulated to the drying tray assembly using a blower without adding further heat to the gas. The gas circulated to the roasting tray may be heated in a heat exchanger before being returned to the roasting tray assembly.

  A portion of the exhausted gas is removed from the treatment tank for use outside the roasting system. Another portion of the exhausted gas is indirectly heated in the heat exchanger 84 (or other heat transfer device) and returned to the gas inlet manifold 24 at the top of the processing bath 10. The heat exchanger 34 applies thermal energy, for example, to heat the exhaust gas from about 250 ° C. to about 300 ° C., and further to about 380 ° C. Reheating and recirculating the exhaust gas reduces the amount of additional pressurized heated oxygen deficient gas needed to supply the treatment vessel gas inlet manifold.

  The exemplary process flow in FIG. 16 is illustrated such that the pressure vessel 10 has one drying tray assembly 16, four roasting tray assemblies 18 and two cooling tray assemblies 20. Hot oxygen-deficient gas circulates through the pressurized tank, blowers 74, 79 and heat exchanger 84 at an elevated pressure in the range of 3-20 Barg (300-2,000 kilopascals) or 5-8 Barg. Hot gas for the drying tray assembly 16 and roasting tray assembly 18 is provided from a heat exchanger 84. Thermal energy is added to the oxygen-deficient gas flowing through the heat exchanger, for example, by hot gas 88 from a combustion device. The warm combustion gas discharged from the heat exchanger 84 flows into the warm air that flows to the combustion device.

  FIGS. 17 and 18 illustrate a process flow in which the dry gas flowing to the top inlet 90 is lower by, for example, 10 ° C. to 30 ° C. than the oxygen-deficient gas flowing to the roasting tray assembly 18. 17 and 18, the gas flowing to the top inlet 90 is also injected into the cooling tray assembly 20.

  The oxygen-deficient gas shown in the process flow of FIGS. 16-18 is circulated to the pressurized treatment tank 10 in a substantially closed gas loop system.

  A portion of the gas is removed from the system as bleed off gasses 90. Some of the gas is from the bottom one or several roasting tray assemblies, all of the roasting tray assemblies, an intermediate set of roasting tray assemblies, or gas removed from the drying tray assembly It is. The bleed-off gas is selected to have a high concentration of by-products of the roasting reaction that is removed and later burned or otherwise processed. Alternatively, the bleed-off gas is selected to have a low concentration of by-products of the roasting reaction used in combustion or other processes.

  The oxygen-deficient gas is circulated through the treatment tank 10 and the heat exchanger 84. Blowers 74, 76 and 78 provide the motive force for circulating the gas. Hot gas from the roasting tray assembly flows through the high temperature blowers 76 and 74 and the heat exchanger 84 before being returned to the roasting tray assembly 18 and, optionally, the top inlet 86 of the processing bath. A plurality of blowers 74, 76 are used to provide the flow rate required to circulate gas through many roasting tray assemblies. The valve 80 between the blower 74 and the blower 76 remains open to allow high temperature gas to flow through these blowers in parallel. The valve 82 is closed to prevent the hot gas flowing through the high temperature blowers 74, 76 from mixing with the low temperature gas flowing through the low temperature blower 78. Valves 80, 82 are set to open or close depending on the amount of hot gas extracted from the processing bath relative to the amount of cooler gas extracted from the processing bath.

  A relatively cooler oxygen deficient gas is extracted from the cooling tray assembly 20, the treatment tank cooling zone 22 (eg, through screen 65), optionally from the drying tray assembly 16, and is extracted from the roasting tray assembly. It flows through a pipe separated from the pipe used for the gas. The cooler gas is removed by the low temperature blower 78 through the extraction nozzle 36, which pushes the gas back into the treatment tank where the gas passes through the injection nozzle 34 and the cooling tray assembly 20. And enters the top of the cooling zone 22 through a nozzle 92, optionally aligned with the bottom tray assembly.

  The bleed-off gas provides a means for removing the main by-product of the roasting reaction that occurs in the treatment tank 10. These main by-products include acetic acid, carbon monoxide, carbon dioxide, formaldehyde, formic acid, water, lignin fragments and other minor components. The main by-product is generally gaseous at the temperature and pressure at which the roasting reaction takes place in the treatment tank. Some of the by-products are in the form of aerosols or fine coals carried in the bleed-off gas. Similarly, fine particles of lignocellulosic material from biomass flow with the gas as it passes through the screens in the trays and processing tanks and is carried out of the system by the bleed-off gas.

  Major by-products can combine and condense to form tar-like materials. If condensed in the treatment tank and downstream process components, tar-like materials may accumulate on the surfaces of the treatment tank and the components, particularly on the internal surfaces of the piping and heat exchangers.

  The gas circulating through the reaction vessel 10 and the heat exchanger 84 may be treated to remove reaction byproducts from the circulating gas. The system for circulating gas through the reaction vessel 10 and heat exchanger 84 includes a separation device 96 for removing reaction byproducts. Separator 96 is a condensing device that cools the gas to condense and remove by-products into a liquid before the gas is reheated in a heat exchanger. Other examples of separation device 96 are devices that oxidize by-products, devices that catalytically convert by-products, devices that filter by-products from the gas stream, and for separating particles from the gas stream. A flow separator such as a cyclone that uses centrifugal force. These separation devices 96 are used alone or in combination in the system. By-products separated by these constituents may be further processed by separation, concentration or purification to useful products. The bleed-off gas 90 removes main by-products from the reaction vessel while these by-products are in gaseous form. As shown in FIGS. 16 and 17, bleed-off gas is extracted from the drying tray assembly, in particular from the extraction gas stream flowing from the extraction nozzle 36 for the drying tray assembly. The gas extracted from the drying tray assembly is rich in moisture and tends to be below the temperature required to initiate roasting. As shown in FIG. 18, the bleed-off gas is extracted from the roasting tray assemblies 18, in particular from the height from the middle to the bottom of these tray assemblies 18. The concentration of organic by-products in the gas extracted from the roasting tray assembly is the highest level compared to the gas extracted from the reaction vessel 10.

  The bleed-off gas 90 flows to the combustion device where it is mixed with natural gas or other gaseous fuel and burned. Combustion releases thermal energy from by-products that can be used to reheat the circulating gas in heat exchanger 84. The heat from the combustion may be used to dry and heat the biomass in any dryer 21.

  Although the present invention has been described in relation to what is presently considered to be the most practical and preferred embodiments, the invention is not limited to the disclosed embodiments, and various modifications and equivalents It should be understood that arrangements are also intended to be included within the scope of the appended claims.

Claims (30)

A pressure roasting reaction tank,
A tank wall extending substantially vertically;
A rotatable shaft extending vertically down through the top of the reaction vessel;
A plurality of scraper devices, each at a different height in the reaction vessel, coaxial with the shaft;
A plurality of tray assemblies, each tray assembly being associated with one of the scraper devices, whereby the scraper device is directly above the tray assembly tray;
A plurality of gas extraction openings in the vessel wall;
Including a bottom discharge port of the reaction vessel through which the roasted biomass is discharged,
At least one of the tray assemblies includes a tray, a gas extraction passage below the tray, and a gas injection passage above the tray, the tray being an open mesh or allowing gas flow to pass through the tray. Is impermeable to the passage of biomass,
Each of the trays includes a discharge opening for conveying biomass from the tray to one tray at the bottom of the tray assembly;
The discharge opening in the lowermost tray conveys the biomass to the biomass deposit in the treatment tank,
At least one of the gas extraction openings is aligned with a gas extraction passage, and another one of the gas extraction openings is at a height below the bottom tray assembly and above the biomass deposit. A pressurized roasting reaction tank.   The pressure vessel of claim 1 wherein the tray assemblies and scraper devices are alternately arranged and stacked vertically along the pressure vessel shaft.   3. A pressure vessel according to claim 1 or 2, wherein the tray is formed from at least one of a porous steel mesh or a drilled steel plate.   4. A pressurized bath according to any of claims 1 to 3, wherein the perforations in the tray are drilled holes or laser cut holes or slots.   The pressure vessel of claim 4, wherein the holes or slots in the tray have a cross-sectional area that increases downward.   6. The pressure vessel of claim 5, wherein each slot or hole has a constant cross-sectional upper region and an increasing cross-sectional lower region.   7. A pressurized vessel according to any of claims 4 to 6, wherein the upper edge of the hole or slot is inclined at least along the trailing portion of the edge.   The pressure vessel of any of claims 1-7, wherein at least one of the tray assemblies includes a solid bottom plate.   The pressurized reservoir of claim 8, wherein the gas injection passage for one of the tray assemblies extends between the tray and the solid bottom plate of the next higher tray assembly.   10. A pressurized tank according to claim 8 or 9, wherein the gas distribution manifold passes through or is attached to the bottom plate and is connected to the gas injection passage.   The pressure vessel of claim 10, wherein the gas distribution manifold is at least one of an assembled metal structure and includes a pipe connection.   12. The pressurized tank of claim 10 or 11, wherein the gas distribution manifold includes at least one nozzle that distributes gas over the biomass on the trays of the lower tray assembly.   13. The pressurized tank of any of claims 10-12, wherein the gas distribution manifold includes a plurality of nozzles that direct the gas to flow uniformly over the biomass on the tray of the next lower tray assembly.   14. A pressure vessel according to any of claims 1 to 13, wherein each tray is an annular array of pie-shaped tray segments and the discharge openings are pie-shaped openings in the annular array.   The pressurized tank according to claim 1, further comprising a baffle plate extending in a radial direction in the gas extraction passage.   The pressure vessel of claim 15, wherein the baffle plate extends vertically and is attached to a tray and a bottom plate of the tray assembly.   17. A pressurized vessel according to any of claims 14 to 16, wherein each pie-shaped tray assembly has a side plate extending vertically between the tray and the bottom plate.   18. At least one cleaning nozzle directed to at least one tray, the cleaning nozzle directing a pressurized fluid stream against a tray pore, slot, hole or mesh. Pressurized tank.   The pressure vessel of claim 18, wherein the cleaning nozzle is attached to the lower edge of the blade of the scraper device.   The pressurization tank in any one of Claims 1-19 in which the gas injection path is connected with the at least 1 gas injection port in the wall of a pressurization tank.   21. A pressurized vessel according to any of claims 1 to 20, wherein there is one gas extraction opening for each segment of the tray assembly, the tray assembly being associated with the extraction opening.   A pressure vessel according to any of claims 16 to 21, wherein the scraper device comprises a blade extending from the shaft towards the wall of the pressure vessel, the blade being arranged at an angle around the shaft.   23. A pressurization device according to any of claims 1 to 22, wherein the scraper device rotates with the shaft, and rotation of the scraper device moves the biomass on a tray directly below the scraper device.   24. A pressure vessel according to any of claims 22 to 23, wherein the scraper device includes a central hub secured to the shaft, and the blades of the scraper device extend outwardly from the hub.   25. A pressure vessel according to any of claims 22 to 24, wherein the blade has a radially outer end connected to a collar, the collar being proximate to the wall of the pressure vessel.   26. A pressure vessel according to any of claims 22-25, wherein each of the blades has a lower edge that is one of the ranges 3-5 millimeters (mm), 3-10 mm or 10-25 mm of the tray directly under the blades. .   27. A pressure vessel according to any of claims 22 to 26, wherein the blades are each inclined at 0 to 20 degrees in the direction of rotation of the scraper device with respect to a radial line corresponding to the blade.   28. A pressure vessel according to any of claims 22 to 27, wherein the blade is curved or curved in the direction of rotation of the scraper device.   At least one of the blades of the scraper device includes a radial slot that receives a high pressure passage, the passage including a nozzle that directs gas to a tray below the blade, or a suction port that applies suction to the tray. The pressure tank in any one of 22-28. 30. A pressure vessel according to any of claims 1 to 29, wherein the area under the tray comprises a roasting reaction zone and a cooling zone below the roasting reaction zone.

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