JP6195923B2 - Apparatus and method for gasification - Google Patents

Description

The present invention relates to a circulating fluidized bed (CFB) reactor for heat treatment of an added carbonaceous material, and such a carbonaceous material by pyrolyzing the carbonaceous material in one process step and oxidizing it in another process step. To a method for producing a combustible product gas having a high calorific value of 4-8 MJ / Nm ³ .

  As described in FIG. 1, WO 99/32583 specification describes a particle separator (2) for separating char-containing particles from a pyrolysis reaction chamber (1) and an outlet gas (32) of the pyrolysis reaction chamber. ), A circulating fluidized bed constituted by a char reaction chamber (3) having at least one inlet for particles from the particle separator, and means for recirculating the particles from the char reaction chamber to the pyrolysis reaction chamber A method and apparatus for gasification of solid carbonaceous material including a (CFB) gasifier is described. The operation of the dual chamber CFB gasifier can be controlled in various ways. The disclosed apparatus and method work well at relatively low temperatures below 750 ° C. For success at such an unusually low and well-controlled temperature, the system can eliminate elements such as potassium and phosphorus that are present in or tend to form low melting ash components. Particularly suitable for organic biomass, waste streams and energy crops containing at relatively high concentrations (> 0.2%).

  The decomposition of the added carbonaceous material with the previously disclosed apparatus is an additional fluidized bed between the first char reaction chamber where char particles are gasified and the pyrolysis reaction chamber where new carbonaceous fuel material is added. It can be facilitated by adding a reaction chamber. This effectively increases the reactor volume available for char treatment, thereby increasing the extent of decomposition of the char remaining in the pyrolysis reaction chamber after the initial treatment. However, a series of arrangements of one or more fluidized bed char reaction chambers between the recycle separator and the pyrolysis reaction chamber (1) can cause temperature control problems. The char decomposition reaction is inherently exothermic, whereas the temperature tends to rise in each subsequent fluidized bed char reaction chamber as opposed to the endothermic pyrolysis reaction that predominates in the pyrolysis chamber. In normal operation, it is generally advantageous to maintain the first char reaction chamber at as high a temperature as possible, but still below the ash agglomeration threshold. Typically, endothermic pyrolysis reactions lower the temperature of the pyrolysis reaction chamber to a level that is about 80-200 ° C. below the temperature of the first char reaction chamber. An additional fluidized bed chamber located between the first char reaction chamber (3) and the pyrolysis reaction chamber (1) is usually used, even though it constitutes only 10% of the total char conversion bed area The overall maximum process temperature is 5-20 ° C. higher than the temperature of the first char reaction chamber. This is disadvantageous because it increases the risk of agglomeration of the additional fluidized bed char reaction chamber bed material or requires a lower operating temperature of the first char reaction chamber. This increased agglomeration risk is particularly detrimental when the carbonaceous fuel material has a high alkali, potassium, phosphorus and / or chlorine content. In this case, even a small increase in temperature can promote ash agglomeration, which can cause the bed material to agglomerate and shut down the reactor.

WO 99/32583

  The above problem is that by configuring the reactor to maximize the residence time of gas and particles in the “intermediate” char reaction chamber, and in some cases as a gasifying agent added to the intermediate chamber. It can be avoided by using a higher steam / air ratio.

  This results in a char decomposition reaction based on steam with a higher endotherm, and accordingly, the temperature rise in the intermediate chamber tends to decrease.

1 shows one embodiment of a CFB reactor according to the present invention showing the relative position of the apparatus and piping through which gas and particles flow.

  The average temperature in the chamber is defined as the temperature at a level corresponding to half the height of the chamber.

In some embodiments, the present invention provides:
A first pyrolysis reaction chamber (1) in which the added carbonaceous material is pyrolyzed by contact with hot recycled particles, inlet for carbonaceous material (1a), inlet for fluidized gas (1c), and an outlet (1b) for product gas at the top of the first reaction chamber (1), the product gas carrying char particles containing carbon and recycle inert particles 1, pyrolysis reaction chamber (1),
-One or more separators (4), the inlet (4a) for receiving the product gas carrying the particles from the first reaction chamber (1), and one or more pipes from which the particles exit each separator A separator (4), having an outlet (4b) for entering the first char gasification chamber (5) via (14)
Inlet (5a) for pyrolyzed and recirculated particles, inlet (5b) for fluidizing gas (6) at the bottom of the first char gasification chamber (5), first char gasification chamber Outlet (5d) for product gas at the top of (5) and outlet (5c) for particles at the bottom of the first char gasification chamber (5) and open to the particle return pipe (7) The first char gasification chamber (5), wherein the particle return pipe (7) opens into an intermediate char gasification chamber (9), and An inlet (9a) for the particles from the first char gasification chamber (5) and an inlet (9b) for the fluidizing gas at the bottom of the reactor (9), eg containing O ₂ / H ₂ O And further of the product gas responsible for particles from the top of the chamber (9) Said intermediate char gasification chamber (9), comprising an outlet (9c) for the fluidization, wherein the outlet (9c) has at least one outlet leading to the lower part of the first reaction chamber (1) and is fluidized The intermediate char gasification chamber (9), which opens to a pipe (8) for supplying gas to the first reaction chamber (1),
A circulating fluidized bed (CFB) reactor for heat treatment of added carbonaceous material is provided.

In some embodiments, during operation, a first fluidized bed (11) of particles is provided to a first char gasification chamber (5), the volume of the first fluidized bed (11) being a fluidized gas. Is defined as the volume to the (upper) surface of the same fluidized bed above the level at which fluid is added to the bottom of the fluidized bed, and the space above the volume of the first fluidized bed (11) is gas and entrained particulates. The lower specific gravity freeboard volume containing (13). In some embodiments, in operation, the particles are carried through an intermediate char gasification chamber (9) to form a second fluidized bed (10) of particles (this second fluidized bed (10) Is defined as the volume above the level at which the fluidizing gas is added to the bottom of the fluidized bed and up to the center of the outlet (9c) for the product gas and particles at the top of the intermediate char gasification chamber) The height (h ₁₀ ) of the second fluidized bed (10) of the intermediate char gasification chamber (9) is the height (h ₁₁ ) of the first fluidized bed (11) of the first char gasification chamber (5). )taller than.

  Alternatively, in some embodiments, in operation, particles are transported through an intermediate char gasification chamber (9) to form a second fluidized bed (10) of particles (this second fluidized bed ( The volume of 10) is defined as the volume to the center of the outlet (9c) for the product gas and particles at the top of the intermediate char gasification chamber above the level at which the fluidizing gas is added to the bottom of the fluidized bed ), The pressure difference between the bottom and top of the first char gasification chamber (5) is smaller than between the bottom and top of the intermediate char gasification chamber (9).

  In some embodiments, a small amount of fluidizing gas (usually air), typically less than 15% of the product gas stream, is added through a nozzle located at the bottom of the pyrolysis chamber to free the particles. And mix well. In some embodiments, the reactor is configured such that the nozzle into which the fluidizing gas can be introduced is located within 15% from the bottom of the pyrolysis chamber. As referred to herein, the nozzle is located within 15% of the bottom, ie, the distance from the bottom of the pyrolysis chamber is no more than 15% of the total distance between the bottom of the pyrolysis chamber and the top top surface. It is.

  In some embodiments, the reactor is configured such that the top of the intermediate char gasification chamber is located at a level that is intermediate between the top and bottom levels of the first char gasification chamber. In this regard, a level is “intermediate” if it is at any level below the top of the first char gasification chamber and above its bottom.

  In some embodiments, the reactor is positioned such that the top of the intermediate char gasification chamber (9) is at a level higher than the level at which most of the fluidizing gas in the first char gasification chamber (5) is introduced. Configured to do.

  In some embodiments, the reactor is at a level that is greater than 50% of the internal volume of the intermediate char gasification chamber and below the level at which a major portion of the fluidization gas of the first char gasification chamber is introduced. It is comprised so that it may be located in.

  According to one embodiment of the CFB reactor, the inlet (1c) for fluidizing gas and particles from the intermediate char gasification chamber (9) is for the gas from the fluidized bed char gasification chamber (5). Located below the inlet (1d), that is, upstream.

  According to one embodiment of the CFB reactor, an outlet for ash may be provided in one or more of the reactors (1, 5, 9) as well as in one or more separators (4).

  According to one embodiment of the CFB reactor, the cross-sectional area of the intermediate char gasification reactor is at least 50%, preferably at least 75% smaller than the cross-sectional area of the first char gasification chamber (5).

  In some embodiments, the CFB reactor has an inlet (1c) for fluidizing gas from the intermediate char gasification chamber (9) that has all of the carbonaceous material for the pyrolysis reaction chamber (1). It is configured to be located below the inlet (1a), that is, upstream.

The present invention also provides
A carbonaceous material is introduced into the first pyrolysis reaction chamber in which a fluidized gas having a low O ₂ content and hot inert recirculating particles are flowing and a temperature T ₁ is 400 to 850 ° C. A first process step to produce product gas with chemically converted particles, i.e. char, and recirculated bed particles;
A second process step that recycles the product gas from the first step and separates it from the partially converted char particles, wherein the product gas exits the process while the separated char particles and The bed particles enter a third process step,
A third process step performed in the first char reactor, wherein the carbonaceous material remaining in the separated char is subjected to a cracking oxidation treatment at a temperature T ₂ of 600 to 850 ° C. in the fluidized bed; Producing a product gas that is withdrawn from the top of the first char reactor, all or most of which enters the first process step together with some of the entrained particulates, while the first char reactor The bed particles from the bottom move to the fourth process step,
A fourth process step in which the remaining char is subjected to a second cracking oxidation treatment at a temperature T ₃ of 600-850 ° C. in a fluidized bed to produce a product gas, the product gas together with the recirculated particles Exit the fourth step and enter the first process step as fluidized gas,
A method for producing a product gas having a desired calorific value from a carbonaceous material, comprising the steps of:
The gas residence time (t ₁₀ ) in the fluidized bed of the fourth process step is longer than the gas residence time (t ₁₁ ) in the fluidized bed of the third process step (t ₁₀ > t ₁₁ ).

In some embodiments, the first process step is performed in an atmosphere having a low O ₂ content, typically <1% or less than 5% O ₂ .

According to one embodiment of the method, the residence time t ₁₀ is> 1.2 t ₁₁ , preferably> 1.5 t ₁₁ .

According to one embodiment of the method, the temperature T ₂ of the _third process step and the temperature T ₃ of the fourth process step differ by less than 10 ° C., ie T ₃ −T ₂ <10 ° C., usually T ₃ − T ₂ <5 ° C.

According to one embodiment of the method, the temperature T ₁ is 400-750 ° C., usually 625-775 ° C., and even more preferably 720-770 ° C.

According to one embodiment of the method, the temperature T ₂ is 650-850 ° C., usually 700-800 ° C.

  According to one embodiment of the method, the temperature of the first process step is the flow of fluidized gas to the fourth process step, wherein the fluidized gas and recycle particles to the first process step. It is controlled by adjusting the flow of fluidizing gas to the fourth process step that determines the majority of the flow.

  According to one embodiment of the method, at least 95% by weight of the flooring material in the third process step is an inert particulate material, while at most 5% by weight of the material is a carbonaceous material in the form of char. .

  According to one embodiment of the method, the carbonaceous material fed to the pyrolysis reactor as fuel has an ash content greater than 1% by weight and may have an ash content of 5-50% by weight. .

  In some embodiments, the carbonaceous material used as a fuel has a high potassium (K), chlorine (Cl) and / or phosphorus (P) content greater than 0.2 wt% or greater than 0.3 wt%. In some cases, for example, grain straw, rice straw, and related grain milling waste streams; other crops such as sugar cane, sorghum and sugar beet, corn, potatoes, nuts, tea, cotton, olives, wine and Based on residues such as oil palm, algae including seaweeds, and potential, further marine / fishery derived organic materials; energy crops such as grasses including eg Miscantus and fast-growing trees such as willow and poplar Short cycle forests; crops with high concentrations of salt, eg by growth near salt water or by contact with other salt water; meat and bone meal, etc. Residues from the product industry; livestock manure containing dehydrated manure slurry; municipal and industrial organic waste containing organics from such streams; sewage sludge, etc .; residues containing energy such as fiber and lignin products from wood processing As well as unpurified organic products such as those mentioned above, eg by hydrolysis, extraction and fermentation. In some embodiments, all of the carbonaceous materials listed above can be used as fuel regardless of potassium (K), chlorine (Cl) and / or phosphorus (P) content.

  FIG. 1 shows one embodiment of a CFB reactor according to the present invention and explains how the devices (units) of the CFB reactor can be connected to each other. The figure shows a first reaction chamber 1 with an inlet 1a through which a carbonaceous material is introduced through a pipe 2. The first reaction chamber 1 further includes an outlet 1b for product gas containing particles, an inlet 1c for fluidizing gas, and an inlet 1d for product gas from the first char gasification chamber 5. The fluidizing gas added through inlet 1c is replenished by the addition of additional fluidizing gas added through one or more nozzles to fully distribute the gas and particles at the bottom of the first reaction chamber 1. Can be done.

  In general, an embodiment of a CFB reactor according to the present invention includes a first reaction chamber in which the carbonaceous material is pyrolyzed by contact with hot recycled particles. The fact that the carbonaceous material is pyrolyzed means that the material is decomposed for heat, not for oxidation, and pyrolysis is an endothermic process that requires the addition of heat. The hot circulating particles that transfer heat to the first reaction chamber 1 are usually sand, but may be any inert particulate material that resists abrasion well.

  The carbonaceous material is supplied to the first reaction chamber 1 through the pipe 2 and the inlet 1a. The carbonaceous material may be any carbonaceous material, such as organic materials, coal or petroleum based products, but usually the carbonaceous material is straw or other vegetable waste, soft lignocellulosic biomass, such as Organic materials such as agricultural residues, fertilizers, household waste, dried sewage, dried animal remains or other carbonaceous waste, optionally mixed with inorganic materials.

The first reaction chamber 1 is supplied with a fluidizing gas at the bottom of the chamber, the fluidizing gas provides a fluidized bed for the reaction and transport of particles in the first reaction chamber, and the particles are supplied from the bottom of the chamber. It is transported to the upper outlet 1b of one reaction chamber 1. Typically, the atmosphere in the first reaction chamber 1 is an oxidation where some of the carbonaceous material will eventually become CO ₂ or H ₂ O, that is, heat will be generated instead of combustible products. A low oxygen state is maintained to reduce the occurrence of the reaction. The low oxygen concentration is advantageous for thermal decomposition, that is, decomposition of the carbonaceous material by heat, and the oxygen concentration in the atmosphere of the first reaction chamber 1 is usually very low. For example, the oxygen concentration in chamber 1 is typically less than 1% or less than 5%. In some embodiments, the fluidizing gas is primarily supplied from an intermediate char gasification chamber 9 where a char oxidation reaction occurs that generates heat and reduces the oxygen concentration of the product gas exiting the chamber 9. In some embodiments, some supplemental fluidizing gas may be added directly to chamber 1.

  The optimum temperature in the first reaction chamber 1 depends on the type of carbonaceous material to be gasified, as well as the application of product gas and residual ash / solid product. Typically, it is advantageous to select a temperature in the first reaction chamber 1 that is sufficient to cause a high degree of decomposition of the carbonaceous material, while that temperature is a coagulation of decomposed material and recycle bed material. Should not be high enough to happen. Furthermore, environmentally problematic and hence undesirable polyaromatic hydrocarbons (PAH) tend to form at high pyrolysis temperatures. Usually, if the carbonaceous material is a usual organic material, the average pyrolysis temperature is advantageously 400 to 800 ° C. For biofuel materials such as straw, the temperature is more typically 620-700 ° C, and for very low calorific fuels such as anaerobic digested dehydrated fertilizers from agricultural animals and pretreated sewage sludge Is more typically 500-600 ° C. For example, lower pyrolysis temperatures can be selected for the purpose of producing bio-oil and / or bio-char.

  Usually, the temperature in the first reaction chamber 1 is controlled during operation, mainly by adjusting the air flow to the intermediate char gasification chamber 9 and / or by adjusting the total amount of particles in the gasifier. Is done. The reaction chamber is heated to the operating temperature by the use of an additional burner during initial startup and / or after such initial heating, for example by adding fuel and air / oxygen to the first reaction chamber 1, for example. May be.

  When the product gas carrying the char particles and the recirculated particles exits the first reaction chamber 1 through the outlet 1b, the product gas enters one or more parallel separators 4 via the inlet 4a via one or more pipes 3, The product gas together with the fine particles of particles exits the separator 4 through the outlet 4c and enters the pipe 18, and the separated particles exit the separator 4 through the outlet 4b and enter the pipe 14. The piping 14 carries the particles to the bottom of the char gasification chamber 5 where the particles are received in the fluidized bed 11. The purpose of the separator 4 is to separate the product gas from most of the gas entrained particles, which most of the particles must be transported to the first char gasification chamber 5.

  Particle separation can be any kind of particle separator, such as a dynamic separator, such as a turn chamber, labyrinth, and cyclone separator, or a filtration filter, such as a high temperature bag filter, a porous ceramic filter or a granular bed filter (a combination of the above separators). Can be used. According to one embodiment, the product gas from the first reaction chamber is washed first in the first dynamic separator and then in the second, more effective type of separator. In this case, the recirculation of the particles to the char gasification chamber 5 is mainly performed from the first dynamic separator described above. The second separator can be, for example, a common more effective cyclone separator or a high efficiency filtration filter.

  Usually, the piping 14 carrying the particles from the separator to the first char gasification chamber 5 is provided with means to prevent the gas from rising from the first char gasification chamber 5 through the piping 14 and entering the separator, or It is configured as such.

  Generally, about 70-80% of the organic portion of the carbonaceous material is released as a gas during pyrolysis, and about 20-30% of the organic portion of the carbonaceous material remains in the solid form of char particles. The energy remaining in the char typically constitutes about 30-40% of the total energy content of the original carbonaceous fuel material. The char particles are oxidized by introduction of a gasifying agent at a common temperature in the char gasification chamber. When oxygen is added directly, the oxidation reaction produces a partially flammable gas, is exothermic and raises the temperature in the char gasification chamber. However, an endothermic steam-based char conversion reaction can also be performed, which produces a partially flammable gas but provides a lower temperature. The two purposes of the first char gasification chamber 5 are to raise the temperature of the inert recirculated particles and to optimize the char conversion, i.e. to recover the combustible gas from the previously pyrolyzed carbonaceous particles. Is to optimize. A fine part of the char particles is lost in the separator section, but usually at least 80% is carried from the separator section to the first char gasification chamber 5.

The first char gasification chamber 5 includes an inlet 5a for pyrolyzed and inert recirculated particles and is also supplied via piping 6 to the lower part of the first char gasification chamber 5 in the figure. Including an inlet 5b for fluidized gas. Usually, the fluidizing gas is passed through a number of nozzles (not shown) and / or other air flow distribution means to ensure an appropriate flow pattern to maintain the fluidized bed in the first char gasification chamber 5. The char gasification chamber 5 is supplied. Usually, the first char gasification chamber 5 has a bubble fluidized bed at the bottom. Typically, the gasifying agent is also used as a fluidizing gas, mainly a mixture of air and some steam (H ₂ O), which raises the overall temperature, but the char gasification chamber is also a liquid such as water It may have one or more somewhat different inlets for the gasifying agent, which lowers the temperature in the chamber more effectively than steam.

  The first char gasification chamber 5 includes an outlet 5 d for the gas at the top of the char gasification chamber 5 and an outlet 5 c for the particles at the bottom of the char gasification chamber 5. The outlet 5c opens to the particle return pipe 7, and the particle return pipe 7 opens to the intermediate char gasification chamber 9 through the inlet 9a.

  The average temperature in the first char gasification chamber 5 is usually at least 50 ° C. higher than the temperature in the first reaction chamber 1, which usually means that particles entering the first reaction chamber 1 via the inlet 1c are first in the first. Means at least 50 ° C. higher than the desired operating temperature in the reaction chamber 1. When using a high alkaline fuel, the temperature in the first char gasification chamber 5 is usually maintained below 770 ° C.

The atmosphere in the first char gasification chamber 5 contains oxygen that results in an exothermic oxidation reaction occurring in the first char gasification chamber 5. The oxygen content in the atmosphere of the first char gasification chamber 5 in operation is high enough that most of the char material is decomposed by oxygen. However, in an exemplary embodiment, the oxygen content in the additive gasifier is maintained well below the substoichiometric level, which is the first char gasification chamber 5 via inlet 5a. This means that there is insufficient oxygen to fully oxidize all of the char material added to. In operation, a fluidized bed 11 of particles is provided in the lower part of the first char gasification chamber 5. The volume of this fluidized bed 11, usually a bubbling fluidized bed, is defined as the volume to the same fluidized bed surface above the level at which fluidized gas is added to the bottom of the fluidized bed. The height h ₁₁ of the fluidized bed 11 shown in FIG. The height h ₁₁ of the fluidized bed ₁₁ is evaluated by measuring the differential pressure in the fluidized bed and by comparing these pressures with the pressure measured in the freeboard volume 13 and maintaining it at the desired level. Can do. The freeboard volume 13 is above the volume of the fluidized bed 11, and this freeboard volume 13 is too fine to remain in the gas and bubble bed and is instead carried to the outlet 5d with the gas. Particles that enter the pipe 15. After the gas exits the char gasification chamber 5, the gas enters the first reaction chamber 1 through the piping 17 and the inlet 1d, or part or all of the gas passes through the piping 16 to the CFB reactor. You can either leave.

Particles exiting through the first char gasification chamber 5 through the outlet 5c at the bottom enter the intermediate char gasification chamber 9 through the inlet 9a. The intermediate char gasification chamber 9 further includes an inlet 9b for adding the fluidizing gas at the lower part of the reactor 9, and thus the fluidized bed 10 is formed in the intermediate char gasification chamber 9. The added fluidizing gas is typically primarily air, but may be other gasifying agents, such as O ₂ and / or steam (H ₂ O), while additional gasifying agents. May be liquid water that may be introduced through another inlet. Further, the intermediate char gasification chamber 9 includes an outlet 9c for a product gas carrying particles from the upper part of the chamber 9, and the outlet 9c has a pipe having at least one outlet connected to the lower part of the first reaction chamber 1. Open to 8. That is, the intermediate char gasification chamber 9 supplies the fluidizing gas to the first reaction chamber 1, and the gas generated in the intermediate char gasification chamber 9 is deficient in oxygen, so a major amount is present at the bottom of the first reaction chamber 1. It is not necessary to add an additional oxygen-depleted fluidizing gas, and in particular, the use of an inert gas such as N ₂ as the fluidizing gas can be avoided.

During normal operation, most of the particles entering the intermediate reactor 9 through the inlet 9a are transported up towards the outlet 9c. The exception is that the char particles that are converted to gas in the reaction chamber 9 and the excess particles that make up the ash stream can be removed from the bottom of the chamber 9. The volume of the fluidized bed 10 is defined as the volume above the level at which the fluidized gas is added to the bottom of the fluidized bed and to the center of the outlet 9c for product gas and particles at the top of the intermediate char gasification chamber 9, The height h ₁₀ of the fluidized bed 10 is shown in the figure.

The CFB reactor has a height h _{10 of} the second fluidized bed 10 defined by the fluidized air inlet and the outlet for gas and particles, the first fluidized bed 11 in the char gasification chamber (5). configured to allow higher than the height h _11.

  Usually, less than 30% of the char decomposition occurs in the intermediate char gasification chamber 9 and more than 70% of the char decomposition occurs in the first char gasification chamber 5. This and at least the minimum (obvious) benefit of including an additional intermediate reactor 9 typically gives 70% to 95% of the total mass flow rate of the fluidizer to the first char reactor 5. While adding, it is achieved by adding the remainder, ie 30% to 5%, to the intermediate reactor.

  In order to release the energy remaining in the char that constitutes a substantial portion of the total energy of the carbonaceous fuel material charged to the CFB reactor, the first char gas does not risk the aggregation of particles in the fluidized bed. It is desirable to operate the conversion chamber 5 at as high a temperature as possible. If the highest allowable temperature is obtained in the first char gasification chamber 5, the temperature of the downstream fluidized bed, i.e. the fluidized bed in the intermediate char gasification chamber, is 10-20 than the temperature of the first char gasification chamber 5. This can be a problem because it can cause material agglomeration and shut down the CFB reactor or require a lower temperature in the first char gasification chamber.

  By adjusting the height of the fluidized bed in each of the first char gasification chamber 5 and the intermediate char gasification chamber 9, it is possible to increase the residence time of the gas and particles in the intermediate char gasification chamber 9. . Increasing these residence times makes it possible to cause a slow vapor endothermic reaction in the intermediate char gasification chamber 9 in addition to the dominant and fast exothermic reaction. Steam-based endothermic reactions are also facilitated by using a larger steam / oxygen ratio compared to that used in the first char gasification chamber with a gasifying agent introduced into the intermediate char gasification chamber. . In the most typical example of adding oxygen by adding air, the appropriate vapor / air mass flow ratio in the intermediate chamber is greater than the corresponding ratio in the first char gasification chamber, typically , At least 0.05 (ie> 5% steam) and can be 0.1 or 0.2 or 0.5. Due to the endothermic reaction time, the average temperature in the intermediate char gasification reactor is lower and the temperature in the intermediate char gasification reactor is less than 10 ° C. than the temperature in the first char gasification chamber 5. Preferably, it can be kept below 5 ° C. This also increases the volume of this chamber with char decomposition in the intermediate reactor 9 without having a problematic temperature rise of about 10-20 ° C compared to the temperature in the first char reactor 5 It means that it becomes possible to increase by doing. Providing the longer gas residence time in the intermediate reactor, thus converting more char by a slow endothermic reaction, also simply converts more heavily converted steam or water, for example. It is a better solution to avoid the problematic temperature rise than adding the same cooling effect by adding.

  The cross-section of the intermediate char gasification chamber typically has a certain amount of gasifying agent proportional to the mass flow of gasifying agent added to the first reaction chamber 1 (and also approximately the same surface flow that occurs). It is dimensioned to be consumed (at a conversion rate). The fluidizing gas traveling through the intermediate char gasification chamber 9 carries heated inert particles and needs to be adjusted to a sufficiently low oxygen content, and the flow in the intermediate char gasification chamber Although it is possible to increase the residence time by reducing the flow rate of the gasification gas, the minimum flow rate of the fluidization gas is mainly defined by the need for transport of particles through the chamber.

The product gas typically has a high heating value of 4-8 MJ / Nm ³ . This calorific value range is typically that of an air-blown gasifier, while a high calorific value is obtained by using a gasifying agent having a high content of oxygen compared to nitrogen. be able to.

The invention also relates to a method comprising the following steps:
1) Temperature T ₁ is a 400 to 850 ° C., introducing carbonaceous material into the fluidizing gas and hot inert recycling particles have a low O ₂ content of the first reaction chamber. The carbonaceous material is thermally decomposed, that is, decomposed by heat. All materials, ie char particles and inert heat transport particles, are carried by the product gas to an outlet at the top of the first reaction chamber, through which the product gas and particles exit the first process step. For example, there may be an outlet for extracting ash containing oversized particles from the bottom of the pyrolysis reaction chamber 1.
2) The product gas carrying the particles enters the separation zone (where the product gas is separated from the particles) and the product gas having an increased heating value compared to the supplied fluidized gas is collected Or consumed directly while the separated particles are transported into the char gasification chamber.
3) Residual carbonaceous material, i.e. char particles undergo decomposition treatment at a temperature T ₂ of the 600 to 850 ° C. in a fluidized bed. Product gas from this process step is withdrawn from the char gasification chamber and enters the first process step, for example with a portion of the gas entrained particulates. A portion of the product gas may be removed from the process instead of entering the first reaction chamber. Particles other than the particles transported with the product gas or removed for circulation control purposes are transported to the fourth process step.
4) Furthermore, the remaining carbonaceous material undergoes a second decomposition treatment at a temperature T ₃ of 600 to 850 ° C. in the fluidized bed. Product gas and recirculated particles exit the fourth step and enter the first process step as fluidized gas and heat-carrying particles. The fluid bed gas residence time (t ₁₀ ) in the fourth process step is longer than the fluid bed gas residence time (t ₁₁ ) in the third process step (t ₁₀ > t ₁₁ ). In some embodiments, the product gas from the fourth process step enters the first process step as a fluidizing gas from below the inlet for the carbonaceous material in the first reaction chamber.

The description of the provided embodiments is merely representative and is not intended to limit the scope of the invention as defined by the claims.
Examples of the present invention include the following.
[1] A first pyrolysis reaction chamber (1) in which the added carbonaceous material is pyrolyzed by contact with hot recirculating particles, the inlet for the carbonaceous material (1a), fluidized gas Inlet (1c) for gas, outlet (1b) for product gas carrying carbon-containing char particles and recycle inert particles at the top of the first reaction chamber (1), and first char gas A first pyrolysis reaction chamber (1), having an inlet (1d) for product gas from the gasification chamber (5),
One or more separators (4), the inlet (4a) for receiving the product gas carrying the particles from the first reaction chamber (1), and one or more pipes (the particles exit the separators) 14) a separator (4), having an outlet (4b) for entering the first char gasification chamber (5) via
Inlet (5a) for pyrolyzed and recirculated particles, inlet (5b) for fluidizing gas (6) at the bottom of the first char gasification chamber (5), first char gasification chamber The outlet (5d) for the product gas at the top of (5) and the outlet (5c) for the particles at the bottom of the first char gasification chamber (5) and open to the particle return pipe (7) A first char gasification chamber (5) having a particle return line (7) opening into an intermediate char gasification chamber (9); and
The inlet (9a) for the particles from the first char gasification chamber (5) and the inlet for the fluidizing gas (eg gas containing O ₂ / H ₂ O ) at the bottom of the reactor (9) ( 9b) and further comprising an outlet (9c) for the product gas carrying particles from the upper part of the chamber (9), which has at least one outlet leading to the lower part of the first reaction chamber (1) And an intermediate char gasification chamber (9) that also includes an outlet (9c) that opens into a pipe (8) that supplies fluidizing gas to the first reaction chamber (1)
A circulating fluidized bed (CFB) reactor for heat treatment of added carbonaceous materials.
[2] The inlet (1c) for fluidizing gas from the intermediate char gasification chamber (9) is below, ie upstream from, the inlet (1d) for gas from the first char gasification chamber (5) The CFB reactor according to [1], which is located in
[3] The CFB reactor according to [1], wherein an outlet for ash is provided at the bottom of one or more separators (4) and / or an intermediate char gasification chamber (9).
[4] The CFB reactor according to [1], wherein the cross-sectional area of the intermediate char gasification reactor is at least 50% smaller than the cross-sectional area of the first char gasification chamber (5).
[5] The inlet (1c) for fluidizing gas from the intermediate char gasification chamber (9) is below, ie upstream of any inlet (1a) for carbonaceous material to the pyrolysis reaction chamber (1) The CFB reactor according to [1], which is located on the side.
[6] The reactor is
(A) the top of the intermediate char gasification chamber is located at an intermediate level between the top level and the bottom level of the first char gasification chamber;
(B) the top of the intermediate char gasification chamber (9) is located at a level higher than the level at which most of the fluidizing gas in the first char gasification chamber (5) is introduced; and / or
(C) More than 50% of the volume of the intermediate char gasification chamber is below the bottom of the first char gasification chamber and is located at a level below the bottom of the pyrolysis chamber
The CFB reactor according to [1], which is configured as follows.
[7] In operation, a first fluidized bed (11) of particles is provided to a first char gasification chamber (5), the volume of the first fluidized bed (11) passing the fluidized gas to the bottom of the fluidized bed. Defined as the volume that exists above the level added to the surface of the same fluidized bed and above the volume of the first fluidized bed (11) is the lower specific gravity freeboard volume (13) containing gas and entrained particulates The CFB reactor according to [1].
[8] During operation, the particles are transported through an intermediate char gasification chamber (9) to form a second fluidized bed (10) of particles, and the volume of this second fluidized bed (10) is fluidized Defined as the volume to the center of the outlet (9c) for product gas and particles above the level at which the gas is added to the bottom of the fluidized bed and at the top of the intermediate char gasification chamber, of the intermediate char gasification chamber (9) The height (h ₁₀ ) of the second fluidized bed (10) is higher than the height (h ₁₁ ) of the first fluidized bed (11) of the first char gasification chamber (5). CFB reactor.
[9] During operation, the particles are transported through an intermediate char gasification chamber (9) to form a second fluidized bed (10) of particles, and the volume of this second fluidized bed (10) is fluidized The first char gasification chamber (5) is defined as the volume to the center of the outlet (9c) for the product gas and particles above the level at which gas is added to the bottom of the fluidized bed and at the top of the intermediate char gasification chamber The CFB reactor according to [1], wherein the pressure difference between the bottom and the top of the middle is smaller than between the bottom and the top of the intermediate char gasification chamber (9).
[10] The CFB reactor according to [1], further including a nozzle capable of introducing a fluidizing gas within 15% from the bottom of the pyrolysis chamber.
[11] Introducing carbonaceous material into the first pyrolysis reaction chamber in which fluidized gas with low O ₂ content and hot inert recycle particles flow and temperature T ₁ is 400-850 ° C. A first process step that produces a product gas carrying particles (ie char) and recirculated bed particles partially converted from the first process step;
A second process step that separates the product gas from the first step from the recirculated and partially converted char particles, wherein the product gas exits the process while separated char particles and bed particles Enters the third process step, the second process step,
A third process step performed in the first char reactor, wherein the carbonaceous material remaining in the separated char is subjected to a cracking oxidation treatment at a temperature T ₂ of 600 to 850 ° C. in the fluidized bed ; Producing a product gas that is withdrawn from the top of the first char reactor and the product gas enters the first process step along with some of the entrained particulates, while the bed particles from the bottom of the first char reactor Is carried to the fourth process step, the third process step, and
A fourth process step in which the remaining char undergoes a second cracking oxidation treatment at a temperature T ₃ of 600-850 ° C. in the fluidized bed, leaving the fourth step together with the recirculated particles and fluidizing Generating a product gas that enters the first process step as a gas, a fourth process step;
A method for producing a product gas having a desired calorific value from a carbonaceous material, comprising:
The method wherein the gas residence time (t ₁₀ ) in the fluidized bed of the fourth process step is longer than the gas residence time (t ₁₁ ) in the fluidized bed of the third process step (t ₁₀ > t ₁₁ ).
[12] (a) t ₁₀ > 1.2 t ₁₁ , preferably> 1.5 t ₁₁ ;
(B) The temperature T ₂ of the _third process step and the temperature T ₃ of the fourth process step differ by less than 10 ° C., ie T ₃ -T ₂ <10 ° C., usually T ₃ -T ₂ <5 ° C. Yes;
(C) the temperature T ₁ is 400-800 ° C, usually 625-775 ° C; and / or
(D) temperature T ₂ is 650 to 800 ° C., usually 700 to 800 ° C.,
The method according to [11].
[13] The temperature of the first process step is controlled by adjusting the flow of fluidizing gas to the fourth process step that determines the flow of fluidizing gas and recirculated particles to the first process step. The method according to [11].
[14] The method according to [11], wherein at least 95% by weight of the floor material in the third process step is an inert particulate material, while less than 5% by weight of the material is a remaining carbonaceous material.
[15] Grain straw, rice straw, related grain whitening waste logistics; any other crop such as sugar cane, sorghum, sugar beet, corn, potato, nuts, tea, cotton, wine, any one or more carbonaceous materials Olive and oil palm residues; eg algae including seaweeds; energy crops including grasses including eg Miscantus; residues from short-circulating forest crops based on fast-growing trees including willows and poplars; eg near salty water Crops with high concentrations of salt by growing on or in contact with water containing other salts; residues from the meat products industry including meat and bone meal; livestock manure containing dehydrated manure slurries; organics from such streams Municipal and industrial organic waste containing sewage sludge; or residues containing energy such as fiber and lignin products from the processing of wood and refined Including organic products not, The method according to [11].
[16] As described in [11], in operation, the pressure difference between the bottom and top of the first char gasification chamber (5) is smaller than between the bottom and top of the intermediate char gasification chamber (9) the method of.

Claims (25)

A first pyrolysis reaction chamber (1) in which the added carbonaceous material is pyrolyzed by contact with hot recycled particles, the inlet for the carbonaceous material (1a), for the fluidized gas An inlet (1c), an outlet (1b) for the product gas carrying carbon-containing char particles and recycle inert particles at the top of the first reaction chamber (1), and a first char gasification chamber ( 5) a first pyrolysis reaction chamber (1), having an inlet (1d) for product gas from
One or more separators (4), the inlet (4a) for receiving the product gas carrying the particles from the first reaction chamber (1), and one or more pipes (the particles exit the separators) 14) a separator (4), having an outlet (4b) for entering the first char gasification chamber (5) via
Inlet (5a) for pyrolyzed and recirculated particles, inlet (5b) for fluidizing gas (6) at the bottom of the first char gasification chamber (5), first char gasification chamber The outlet (5d) for the product gas at the top of (5) and the outlet (5c) for the particles at the bottom of the first char gasification chamber (5) and open to the particle return pipe (7) A first char gasification chamber (5), wherein the particle return pipe (7) opens into an intermediate char gasification chamber (9), and the first char gasification chamber (5) includes an inlet (9b) for fluidizing gas to the bottom of the inlet for the particles from reduction chamber (5) (9a) and the chamber (9), further, the particles from the upper portion of the chamber (9) The outlet (9c) for the product gas to be supported An outlet (9c) having at least one outlet leading to the lower part of the first reaction chamber (1) and opening into a pipe (8) for supplying fluidized gas to the first reaction chamber (1) Intermediate char gasification chamber (9) including
A circulating fluidized bed (CFB) reactor for heat treatment of added carbonaceous materials.   The inlet (1c) for the fluidizing gas from the intermediate char gasification chamber (9) is below, ie upstream from, the inlet (1d) for the gas from the first char gasification chamber (5) of the fluidized bed The CFB reactor of claim 1, located in   The CFB reactor according to claim 1, wherein an outlet for ash is provided at the bottom of one or more separators (4) and / or an intermediate char gasification chamber (9). The CFB reactor according to claim 1, wherein the cross-sectional area of the intermediate char gasification chamber is at least 50% smaller than the cross-sectional area of the first char gasification chamber (5).   The inlet (1c) for fluidizing gas from the intermediate char gasification chamber (9) is located below, ie upstream from any inlet (1a) for carbonaceous material to the pyrolysis reaction chamber (1) The CFB reactor according to claim 1.   The CFB reactor of claim 1, wherein the reactor is configured such that the top of the intermediate char gasification chamber is located at an intermediate level between the top level and the bottom level of the first char gasification chamber.   The reactor is configured such that the top of the intermediate char gasification chamber (9) is positioned at a level higher than the level at which a majority of the fluidizing gas in the first char gasification chamber (5) is introduced. Item 2. The CFB reactor according to Item 1.   The reactor is configured such that more than 50% of the volume of the intermediate char gasification chamber is below the bottom of the first char gasification chamber and is located at a level below the bottom of the pyrolysis chamber The CFB reactor according to claim 1.   In operation, a first fluidized bed (11) of particles is provided to the first char gasification chamber (5), and the volume of the first fluidized bed (11) is such that the fluidized gas is added to the bottom of the fluidized bed. Defined as the volume above and to the surface of the same fluidized bed, above the volume of the first fluidized bed (11) is a lower specific gravity freeboard volume (13) containing gas and entrained particulates. Item 2. The CFB reactor according to Item 1. In operation, particles are transported through an intermediate char gasification chamber (9) to form a second fluidized bed (10) of particles, the volume of which is the fluidized gas flowing through the second fluidized bed (10). Defined as the volume to the center of the outlet (9c) for the product gas and particles above the level added to the bottom of the bed and at the top of the intermediate char gasification chamber, the second of the intermediate char gasification chamber (9) higher than the fluidized bed (10) of a height (h ₁₀₎ the first fluidized bed (11) of the height of the first Chagasu reduction chamber (5) (h _11), CFB reactor according to claim 1 .   In operation, particles are transported through an intermediate char gasification chamber (9) to form a second fluidized bed (10) of particles, the volume of which is the fluidized gas flowing through the second fluidized bed (10). Defined as the volume to the center of the outlet (9c) for product gas and particles above the level applied to the bottom of the bed and at the top of the intermediate char gasification chamber, and the bottom of the first char gasification chamber (5) and The CFB reactor according to claim 1, wherein the pressure difference between the top and the bottom of the intermediate char gasification chamber (9) is smaller.   The CFB reactor according to claim 1, further comprising a nozzle capable of introducing a fluidizing gas within 15% from the bottom of the pyrolysis chamber. A first introducing a carbonaceous material into a first pyrolysis reaction chamber in which a fluidized gas having a low O ₂ content and hot inert recycle particles flow and a temperature T ₁ of 400-850 ° C. A first process step that produces a product gas carrying particles (ie char) and recirculated bed particles partially converted from the first process step,
A second process step that separates the product gas from the first step from the recirculated and partially converted char particles, wherein the product gas exits the process while separated char particles and bed particles Enters the third process step, the second process step,
Third a process step performed in the first char gasification chamber, the carbonaceous material remaining in the separated char is subjected to oxidative decomposition treatment at a temperature T ₂ of the 600 to 850 ° C. in a fluidized bed to produce the product gas withdrawn from the top of the first char gasification chamber, while the product gas enters the first process step together with part of the entrained fine particles from the lower portion of the first char gasification chamber A third process step wherein the bed particles are conveyed to a fourth process step, and a fourth process step wherein the remaining char undergoes a second cracking oxidation treatment at a temperature T ₃ of 600-850 ° C. in a fluidized bed A fourth process step that produces a product gas that exits the fourth step together with the recirculated particles and enters the first process step as a fluidizing gas;
A method for producing a product gas having a desired calorific value from a carbonaceous material, comprising:
The method wherein the gas residence time (t ₁₀ ) in the fluidized bed of the fourth process step is longer than the gas residence time (t ₁₁ ) in the fluidized bed of the third process step (t ₁₀ > t ₁₁ ). t ₁₀ is> 1.2 t _11, The method of claim 13. t _Ten > 1.5t ₁₁ 14. The method of claim 13, wherein 14. The method according to claim 13, wherein the temperature T ₂ of the _third process step and the temperature T ₃ of the fourth process step differ by less than 10 ° C., ie T ₃ −T ₂ <10 ° C. 14. The method according to claim 13, wherein the temperature T ₂ of the _third process step and the temperature T ₃ of the fourth process step differ by less than 5 ° C., ie T ₃ −T ₂ <5 ° C. The method according to claim 13, wherein the temperature T ₁ is 400 to 800 ° C. Temperature T ₁ The method according to claim 13, wherein is 625 to 775 ° C. Temperature T ₂ is 650 to 800 ° C., The method of claim 13. Temperature T ₂ The method according to claim 13, wherein is 700 to 800 ° C.   The temperature of the first process step is controlled by adjusting the flow of fluidizing gas to the fourth process step that determines the flow of fluidizing gas and recirculated particles to the first process step. Item 14. The method according to Item 13.   14. The method of claim 13, wherein at least 95% by weight of the floor material in the third process step is an inert particulate material, while less than 5% by weight of the material is a remaining carbonaceous material. Carbonaceous material is 1 or more optional, cereal straw, rice straw, associated grain refined waste stream; sugarcane, sorghum, sugar beet, maize, potato, nuts, tea, cotton, wine, crops, including olive and palm oil Residues ; Algae , Seaweeds; Energy crops including grasses , Miscantus ; Residues from short-circulation forest crops based on fast-growing trees including willows and poplars ; Crops with high salt concentrations upon contact with water; residues from the meat products industry including meat and bone meal; livestock manure including dehydrated manure slurry; urban and industrial organics containing organics from urban and industrial organic waste waste; sewage sludge; including or residue containing energy, fibers and lignin products due to processing of wood, and the organic product that does not purified, claim 13 The method described.   14. The method according to claim 13, wherein, in operation, the pressure difference between the bottom and top of the first char gasification chamber (5) is smaller than between the bottom and top of the intermediate char gasification chamber (9).

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