JPH05504189A - Circulating fluidized bed combustion using CO combustion promoter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Circulating Fluidized Bed Combustion Using CO Combustion Promoter This invention relates to a circulating fluidized bed combustion apparatus. Ru.

Regeneration equipment with fluidized catalytic cracking (FCC) equipment, fluidized coal combustion equipment and There are many ways to create combustion, including "regenerators" with dynamic cokers. Fluidized bed processes are known.

Many fluidized bed combustion processes use carbon (in the form of coke, hydrocarbons or coal) Only partial combustion is performed to convert CO□. Partial combustion to CO is an energy means a source of air pollution.

In the FCC regenerator, a CO combustion promoter such as Pt is circulated and retained in the catalyst. It is known to add 0.1-1 to achieve complete CO combustion. Adding 0 ppm by weight of Pt, typically 0.5 to 2 ppm by weight, This is normal in Rocess. For more complete CO combustion, Pt makes the regenerator even more effective. Driven hot. Burning charcoal reduces CO and produces more CO2. More air is supplied per unit weight of element. CO emissions will be reduced by a considerable amount. However, NOx emissions increase, probably due to a more oxidizing atmosphere.

pt accelerators last long in industrial FCC equipment, remaining in the equipment for many months It has activity and catalyst life similar to conventional FCC catalysts.

Similar results were obtained with thermophore catalytic cracking ( TCC) process.

Both the FCC and TCC processes use fairly clean feedstock (heavy carbonized Contains a stable long-life catalyst that is an ideal support for CO combustion promoters such as hydrogen) and Pi .

The use of C○ combustion promoters is recommended for fluidized bed coke combustion. US Patent No. 4. ．． No. 515.092 (Walsh et al.) and “A Lab. Latory Study of Veterinary Cork Compassion: Kineti Cus and Catalytic Effects (A Laboratory 5 study of Petroleum Coke Com-bustion: Titled Kinetics and Catalytic Effects) J A related publication by Worunyu et al. The addition of t increases C○ combustion in a single fluidized bed of coke operating at 505°C. It has been reported that it is promoted.

Recent developments include circulating fluidized beds (CFB). bed) This is the industrialization of boilers.

In CFB devices, operation is complex. The fuel usually contains large amounts of sulfur and other Low-grade fuel with impurities, such as coal, in riser combustion equipment. be burned. The fluidized method uses a fast fluidized bed method as raw material. ed bed), that is, there are no large bubbles J. . A high-velocity fluidized bed is powered by fuel, usually added at the bottom of the riser. This is air for baking. In CFB devices, an extremely large range of particle sizes is typically present. do.

Combustion air is generally added from the bottom of the high-velocity fluidized bed, creating a flue Gas is discharged from the top of the high velocity fluidized bed, typically into a cyclone separator.

There, most large particles, typically larger than 100 μm, are collected and simultaneously Finer substances (fly ash) are discharged with the flue gas. be done. The solids collected in the cyclone are recycled to the high-speed fluidized bed.

Heat is removed from the CFB device at many points. CFB equipment is an extreme - or higher for recovering heat from fluidized beds with the advantage of high heat transfer rates It has an area of Most of the equipment is cyclone separator solids outlet and high velocity flow. At least one relatively rich phase fluidized bed heat exchanger is provided in the middle of the moving bed combustor. do.

Fluid flow in a CFB is limited by the particle size of the materials being handled in many CFBs. It is complex because it always covers a wide range. Where coal is the feedstock to the CFB unit In some cases, the particle size distribution ranges from submicron particles to particles several inches in diameter. There are times when it drips.

Particles ranging from submicrons to several microns include fly ash, pulverized contains some grains of crushed dolomite and limestone and perhaps crushed coal. be done.

Particles with a diameter of less than 1100A1 have a short life in the CFB device.

It is common to have a low efficiency cyclone, which is usually fitted to such equipment. Substances larger than 100μm, such as pulverized sulfur-absorbing materials such as coal and dolomite This is because it is necessary to be able to eject fly ash while capturing essentially all of it. Ru.

Materials between 100 μm and 300 μm within the CFB represent the majority of circulating particle retention. . This material is commonly used as dolomite, limestone and SOx acceptor. similar materials, as well as certain parts of lower grade fuels such as coal. Wood chips etc. sulfur receptors when clean or at least low sulfur content fuels are burned. is not required and provides sand or other inert material for fluidization.

Coal particle size varies from a few inches when initially added to the high-speed fluidized bed to large Theoretically, sub-micron particles are produced by the rupture and crushing of coal in particle size. Wander. The majority of coal is large particles, typically 300 μm to 1000 μm. , which tends to elutriate and stay at the bottom of the CFB.

Many CFB devices are designed to handle small amounts of agglomerated ash. C.F. At the temperature at which B is operated (usually 843-899°C (155O-1650'F)) As a result, a large amount of sintering of the ash occurs, which causes the particles to become larger and larger. typically Large ash aggregates on the order of 1000-2000 μm are removed from the bottom of the CFB device. The CFB device can be drained or removed intermittently. is designed.

The chemical reactions that occur during CFB operation are complex. Coke combustion, sulfur and nitrogen Reactions between elementary compounds and adsorbents, reactions between NOx and reducing gases (e.g. C○ that may be present) A typical reaction is to respond.

(No industrial equipment existed in 1978; 100 industrial equipment existed in 1988. Despite the explosive growth in CFB technology (in operation or under construction), this There are several drawbacks to the technology.

Particularly problematic is the tendency for all equipment to operate at the same very high temperatures. , which causes metallurgical, operational and contamination problems. Ma In addition, CFB operations require more air than is stoichiometrically required. made.

A typical circulating fluidized bed structure is described in U.S. Pat. Nos. 4.776.288 and 4.68. No. 8.521.

Staged air supply and stages, as disclosed in U.S. Pat. No. 4.462.341, Circulating Fluidized Bed Combustion System Operating with Staged Combustion, U.S. Patent No. 4,579.07 A circulating fluidized bed combustion apparatus in reduction mode as disclosed in No. Minimize Ox emissions.

The separation means used to remove recycled solids from the flue gas may be a cyclone or No. 4,442,797. It's fine.

Most of the research in circulating fluidized beds has been summarized in two-volume publications. one , “Circulating Fluidized Bed Technology (Ci) rculating Fluidized Bed Technology) , Proceedings on the First International Conference Lens-on-Circulating Fluidized Betsug (Proc. eeding of the F 1rst I internationalC onference on Circulating Fluidized B eds) J, /\Halifax, Nov7” Scotia ( Nova 5cotia), Canada, November 18-20, 1985, Pla Edited by Beer Bass (PrabirB asu), Pergamon Press (Per gamon Press) (hereinafter referred to as CFB I), and the recent , “Circulating Fluidized Bed Technology ( Circulating Fluidized Bed Technology II), Proclaimings on the Second International Can Reference on Circulating Fluidized Betsug (P) roceeding of the 5th century l Conference on Circulating F 1u-idi zed Beds) J, Compiegne,, Fra March 14-18, 1988, Prabir Ba 5u) and Jean F rancois Large), published by Pergamon Press (hereinafter referred to as CFB If).

Other researchers have noticed remaining problems when using CFB devices. for example “Analysis on Circulating Fluidized Bed Co. Passion Technology and Scope for Technology Development Analysis of Circulating Fluidi zed　Bed　Combustion　Technology　andSco pe For Future Development), Takehiko Furuka Ta-kehiko F urukawa and Tadaaki Shimizu (Tad) See page 51 of CFB n. The author is 1. Heat recovery 2. Cyclone design and increased carbon combustion 3. NOx emissions focused on three aspects.

The issue of better carbon combustion and reduced NOx/SOx emissions were related. This section The issue of emissions from CFB boilers is best understood by examining be able to.

CFB boilers are rapidly becoming industrialized due to a number of factors.

The first is fuel flexibility, and CFB boilers can be used with fuels rich in ash and water, as well as with conventional fuels. Boilers can use mixtures of fuels, including difficult-to-combust fuels. engineering Combustion materials that can be burned in commercial CFB boilers include coal, waste wood, and bark. , petroleum coke, petroleum, oil gas, lignite, lignite, beet, coal washing waste, industry Includes sludge and sewage sludge. Combustion efficiencies as high as 99% are often achieved. Ru.

The fuel is easy to handle and supply, with a high rate of heat generation (, power throttling and negative Load tracking was excellent and the CFB demonstrated excellent industrial efficacy performance.

Most importantly, the advantage of CFB boilers is their low emissions. grain Low emissions of CO2, SOx, and NOx allow conventional boilers to use low-grade fuels. If possible, install new CFB boilers in areas where it was impossible to Closed. Such regions include Southern California, Japan and Europe. Sky With increasing concerns about air quality, acid rain and smog, CFB boilers are becoming more and more popular. provides a good alternative for industrial users. The speed of this industrialization has increased over the past 8 It is expected to continue at a fast pace for years.

Good contact between gas and solids in CFB combustion is due to the circulating fine limestone. Provides excellent sulfur capture. Using a Ca/S ratio of 1 to 4, the resulting gypsum is Can be processed safely. The sulfur capture efficiency is more than 90% effective. 843℃～899 °C (1550-1650 °F) combustion temperature and (generally half of the air The staged combustion (introduced as gas) reduces NOx emissions in the range of 50 to 300 ppm. can be kept within the limits. NOx emissions are reduced as excess oxygen in the flue gas is reduced. It decreases over time. This is done using the N.Purge (N, Berge) NOx control. Rule in a Circulating Fluidized Compaster ( NOx Control in a CirculatingF 1uidiz From Figure 5 on page 426 of ed Bed Conbustor), CF BU. It is shown in the cited Figure 2.

Temperature, °C ('F) 843 (1550) 899 (1650) Pressure, kPa ( psig) 117 (2) 124 (3) Superficial velocity, m/m1n (ft/s) 55-219 (3-12) 247-457 (15-25) isoform amount, lb/ lb gms 0.4-1 10-20 Gas residence time 7 seconds 0.5-1 3-4 A sharp increase in CO occurs at 1.5%, so reduce excess oxygen to 2% or less. I can't. This constraint is explained in the third section, which cites Figure 7 of the N.Purge publication. As shown in the figure.

As oxygen concentration decreases, NOx decreases, but CO emissions increase. Acting vine Best operation of the equipment requires sufficient air (at least 20% excess air) to provide complete after-combustion. It is to operate using air) and make it coexist with the emission of NOx.

Analysis of the operation of existing CFB equipment revealed that differences in sedimentation rates in circulating fluidized beds Based on It turned out that it was just that.

A number of drawbacks to CFB devices include CFB combustion equipment, although having a more oxidizing atmosphere in the upper part of the combustion equipment. This problem could be solved if a generally reducing atmosphere was maintained in the region below.

A CFB operator uses a reducing atmosphere during the combustion of coal or other carbonaceous materials. recognized the benefits, but had only achieved limited success with staged air delivery. Ginai. Part of the problem is the lack of supply at the bottom of the coke burner. This increases the need for oxygen-containing gas in the upper part of the coke burner. On the other hand, there is insufficient residence time for satisfactory combustion of CO to CO2. That is.

Operations using staged CO combustion generally come at the cost of increasing CO emissions. and reduce NOx emissions. in the reducing section of the bed by promoting CO combustion. To compensate for the reduction in combustion activity, more excess air is usually added, e.g. Even supplying excess air of the order of 40%.

Conventional CO combustion promoters, such as platinum or palladium promoters used in FCC equipment, Adding additives to a CFB boiler in an unconventional manner can make the CFB unit more efficient. operation, significantly reducing the amount of excess air required to achieve complete co combustion. and NOx emissions can be reduced.

In one aspect, the invention provides: A high-speed fluidized bed of granules with particle diameters of at least the majority greater than 100 μm in contact with an oxygen-containing gas in a generally vertical combustion apparatus comprising: Flue scum/granules discharged from the top of the combustion equipment by burning more carbon-containing materials A circulating fluidized bed combustion region producing a gaseous substance stream, the flue gas stream comprising: Flue gas, fines with particle diameters below 100 μm and 100-400 μm This flue gas stream comprises circulating particles having an average particle size within the range of After passing through the separation means, the particles with a particle size of 100 to 400 μm are small (mostly in the flue). Circulating fluidized bed combustion where gas is recovered and recycled to the circulating fluidized bed combustion zone. In the firing region, Pt, Pd, Ir, Rh, Os and their compounds and 0.001 to 100, based on the weight of circulating particles of accelerator selected from the group of Add CO combustion promoter to the combustion device in an amount equal to ppm by weight, 400-1200 improved by the presence of an accelerator in the carrier with an average particle diameter in the μm range. Provide a method for

In another aspect, the present invention provides a generally vertical containing nitrogen and sulfur impurities through contact with air in combustion equipment. A circulating fluidized bed combustion method for burning carbonaceous materials, comprising circulating particulate matter in a high-speed fluidized bed. The circulating particles in the bed are At least 25% by weight of the material comprises sulfur-accepting material, and the combustion of the carbonaceous material is Occurs in the lower part of the fast fluidized bed - carbon oxides, carbon dioxide, SOx and Forming a dilute phase fluidized bed containing NOx, circulating particles with a diameter of 100 to 400 μm The particles consist of sulfur receptors and fines generated in the high-speed fluidized bed, and are The bed collects essentially all particulate matter larger than 100 μm equivalent diameter and separates it from the flue gas. In both cases, most of the fine particles are discharged, and the particulate matter exceeding 100 μm in diameter is transferred to the dilute phase fluidized bed. The average equivalent particle diameter CO combustion on a carrier with a surface area of 400 to 1200 μm and a surface area of 20ri2/g or more Accelerators are added to the combustion zone, Pt, Pd, Rh.

0.001 to 100 weight of metal or metal compound selected from O5 and Ir It has the advantage that the CO combustion promoter is present in an amount equal to ppI11.

In another embodiment, in a high-speed fluidized bed comprising a circulating sulfur acceptor material. Provided is a method for circulating fluidized bed combustion of coal, in which the majority of the weight is 100 Comprised of ~400 μm granules, the sulfur acceptor absorbs the sulfur produced during the combustion of coal. If Pt, Pd, Ir, Rh5Os reacts with yellow oxide and is used in circulating fluidized bed combustion equipment, CO combustion promoters selected from the group of elemental metals and mixtures and compounds thereof. Added in an amount equal to 0.001 to 100 ppI by weight on a basis of 11, the accelerator is 40 having an average particle diameter ranging from 0 to 1200 μm and a surface area of 20 m2/g or more stoichiometric amount for complete combustion of coal in circulating fluidized bed combustion equipment. It is characterized by operation using 100 to 105% of the theoretically necessary air.

FIG. 1 is a simplified cross-sectional view of a (prior art) circulating fluidized bed combustion apparatus.

Figure 2 shows that in industrial CFB equipment, NOx generation depends on the flue gas oxygen content. It shows how it changes.

Figure 3 shows how CO generation depends on the flue gas 02 content in industrial equipment. It shows how it changes.

A typical circulating fluidized bed combustion apparatus, shown in Figure 1, uses an inert particle solution such as crushed limestone. via conduit 12 and typically supplies 40 to 80% of the air required for combustion. Fuel is supplied via conduit 14 with a primary air source via conduit 16. A baking device 10 is shown. The secondary air source provides the remaining 20-60% of the air required for combustion. from a conduit 18 that supplies Heat exchanger 20. The circulating water passing through 20' is The heat exchanger 20. 20″ conduit 22. When exiting from 22’, it changes to steam. Ru. The gaseous products of combustion (flue gases) are recycled in limestone and in conduit 26. It is discharged from the outlet 24 of the combustion device 10 together with the incompletely burned fuel generated. The ash content is , through the grate 28 and the conduit 30 to a location remote from the combustion device 10. It can be done. The fuel supplied via conduit 14 is hazardous waste that is expensive to dispose of. May contain waste and sludge. Combustion equipment also uses coal, low-value petroleum coke gas or other refinery products can be burned. For example, fuel gas production In refineries that are constrained by It can be burned in a CFB combustion device in combination with raw material waste.

Preferably, the CO combustion promoter is supported on a highly porous carrier. The carrier contains more than 50% Preferably, it has a porosity that is Particle density ranges from 1°4 to 2.4 g/ml, Preferably it should be in the range 1.5-2 g/ml. lots of highly porous aluminum The powder has a particle density of 2 g/ml, making it ideal for use in the present invention.

C○ The majority of the combustion accelerator, preferably 90% or more, is present on the outer surface of the accelerator carrier. Doesn't exist. That is, the CO combustion promoter has an outer shell with less promoter. It has a core rich in promoter metals or metal compounds. Conventional exchange/ Using the impregnation method, the CO combustion promoter is distributed throughout the carrier particles.

co combustion promoters have a relatively large surface area, e.g. greater than 50 mz/g, or The surface area may exceed 500 m2/g, preferably between 75 and 250 m2/g. It is preferable to disperse it on a material having a multilayer structure.

Alumina, due to its porosity, density and large surface area, has a c.

It is an ideal carrier for combustion promoters. All these physical properties are -carbon oxide It maintains a highly dispersed state of platinum, which can quickly promote combustion after converting it into carbon dioxide. It is essential for the purpose of Silica, soricanialumina, kaolin and similar substances can be used.

In contrast, sand is not a porous material and is therefore not suitable for the platinum CO combustion promoter contemplated by the present invention. Not a good carrier for. All Pt exists on the surface, and it is not attached and/or removed by ash. Or, it is easy to lose weight due to corrosion or abrasion. The density of the sand is also somewhat higher than the preferred value (, Generally 2.5 g/ml.

The amount of CO combustion promoter required depends on the efficiency with which it is used in the device and the temperature at which the device is operated. trapped or coated with dirt and slag, fly ash, etc. can vary greatly depending on the amount of combustion promoter metal used.

The CO combustion promoter has an activity of 0 based on the total weight of solids circulating in the CFB. ．． It is preferred to operate with an amount corresponding to 0.001 to 100 ppm platinum. C.F. Due to the high temperatures at which the B equipment is operated, in many cases significantly small amounts of platinum are used, e.g. For example, 0.01 to 10 ppm by weight of platinum (or equivalent amount of other CO combustion Promoter metal, i.e. 3-5 wt ppm Os approximately corresponds to 1 wt ppm pt . ) can be used to drive. 0.1 to 5 pp by weight for operation of many devices This is done using an amount equivalent to m platinum, and very good results are obtained.

It is possible to operate with much higher amounts of CO combustion promoter, e.g. 100-500 ppm Pt equivalent. Although it is possible to convert the Therefore, such operation is not preferred.

Today, there are no CO combustion promoter metals used in fluid catalytic cracking (FCC) units. Any of these can be used in the method of the invention. Pt5Pd, Ir, Rh and Os can be used alone or in combination. Some such as Pt/Rh The combination provides some reduction in NOx emissions and is preferred for use in the method of the invention. There are some bad things.

The same metals used to promote co combustion in FCC equipment are used in the method of the present invention. However, the conventional CO combustion accelerator particles used in FCC are Not suitable for use in inventions.

In typical FCC applications, the accelerator material typically has an average particle size of 40 to Platinum or other C○ combustion promoting metals on a highly porous support that is 80μm exist. Generally, the accelerator contains 0.02.0.1% by weight of platinum, or 0.02.0.1% by weight of platinum. It may be contained in an amount of 5 to 1% by weight. The accelerator typically contains 0.1% platinum by weight. Ru.

If such a drum of CO combustion accelerator were to be added to a CFB device, the accelerator would It only happens that it is immediately blown out of the device along with the fly ash. teeth The average particle size of fly ash produced by most CFB equipment is 75 μm. . Some types of coal have an ash content of 10-20%, therefore CFB equipment Dimensions of recycled dolomite, limestone, sand, etc. used to hold fluidized beds for purposes It is necessary to efficiently remove sub-legal particles. The ash has a diameter of 100-150μ CFB by using a low-efficiency cyclone that has very poor capture of particles smaller than m. efficiently removed in the device.

C○ Combustion accelerator is a substance with a diameter of 100 to 400 μm that is circulated in the CFB device. It is necessary to be present on catalyst support particles that have a sedimentation velocity well above the particles. Reason Ideally, the rapidly settling C○ combustion accelerator of the present invention would not be circulated in a circulating fluidized bed; Instead of a very fast "slip" in a CFB combustion device, have a very long residence time compared to circulating materials of 100-300 μm, or Remains relatively calm (static) within the CFB floor. CFB combustion equipment produces a lot of condensate. This means that large particles of coal, wood chips, etc. Large particles such as lime and dolomite are present and aggregate. these big Difficult particles remain in the lower part of the bed due to their large size, weight and terminal velocity. . These large particles, to some extent, rapidly fragment the sedimentation promoter. It can function as a carrier.

Dolomite, clay, and sand circulate easily with the terminal velocity of large particles at the bottom of the fluidized bed. Rapidly settling particles with a terminal velocity intermediate to that of particles of 100-400 μm such as The rapid settling of the present invention in the middle part of the CFB combustion zone by using CO combustion promoters can be retained.

This has many advantages. CO combustion promoters are those intended for use in the present invention. A very effective oxidizing catalyst at temperatures of 704-927°C (1300-1700°F). Functions as a medium. A small amount of CO fuel corresponding to 0.001-100 ppm Pt Operating with oxidation accelerator metals significantly reduces CO emissions.

Due to the high settling velocity of the co combustion promoter, a very small amount of promoter circulates through the CFB device. There is essentially nothing lost in a cyclone. The accelerator is CFB as it tends to remain static in the middle and upper regions of the combustion device region. , or tend to remain that way for a long time even if it is not static, causing local combustion. The accelerator spends little time in the lower region, which can be very hot due to calcination. It doesn't grow. “Suspended” combustion accelerators provide some protection from fly ash deposition . In some CFB units, some of the ash content of the coal from the bottom of the CFB unit is large. It is extracted as an aggregate. Some equipment allows continuous removal of large natural aggregates. Yes, and other equipment removes ash intermittently. Most fly ash has an ash content Even in installations where agglomerates are a problem, they are removed with the flue gas.

Another advantage of using a rapid settling aid is that Pt, etc., can be used when it is most needed. i.e. directly above the coke or coal burning area of the combustion device. and 02 are concentrated in areas where there are many.

CO combustion promoters are of no use, for example, in the zip leg of a cyclone.

Most of the ash agglomeration occurs through the bottom of the combustor area, so this The lifespan of fast-settling CO combustion promoters is reduced because they are suspended relatively permanently above the combustion zone. is expected to extend considerably.

The CO combustion promoter comprises particles with an average particle size of 200 to 6000 μm, preferably 5 Particles with an average diameter of 00 to 500011 m, most preferably 750 to 2500 μm may be placed on particles of size.

For optimal results, CO combustion promoters should be used (larger particles, e.g. coal floating above the fluidized bed of a relatively dense phase, typically the volume of the combustor. It tends to stay for a long time in the relatively dilute phase region that occupies 50-90% of the upper part. Make the dimensions so that Therefore, the preferred size of the CO combustion promoter is 400-12 00 μm1, preferably 500 to 1000 μm, and the most preferable dimension is 5 It is 50 to 750 μm.

Low quality due to power consumption and heating of excess flue gas discharged into the stack In order to minimize energy loss, CO and CO in the stack gas are and/or 02 concentration to ensure that there is no more than 5% excess air, more preferably It is advantageous to supply less than 5% excess air, most preferably less than 2% excess air. It is. Therefore, the method of the present invention provides less overload than prior art CFB devices. It can be operated with the amount of surplus air.

Rather than reducing the amount of air added, the method of the present invention adds air blowing capability and combustible materials without requiring an increase in the size of the CFB combustion equipment. can greatly increase the supply amount. The only constraint is that e.g. In order to recover the large amount of heat released when increasing the proportion of coal supplied to the It is the capacity of the heat exchange means for

One or more air supplies at different levels within the CFB combustion device Uno is preferable. Staged air supply ensures stoichiometric requirements in the richest beds. Preferably, 70-90% of the required air is provided. The density of this area is The processing amount, combustible materials, etc. may vary slightly depending on the equipment, or even with the same equipment. affected by. Typically, a highly expanded, high-velocity fluidized bed of particles It has an average particle diameter of more than μm. Typically, this highly expanded bed is C It occupies 10-40% of the vertical distance of the FB combustion device.

Above this high velocity fluidized bed is a region of more dilute phase.

Preferably, a sufficient amount of air is added immediately downstream of the fast fluidized expanded bed region to reduce the CO It is present up to 100-110% of the amount stoichiometrically required for complete combustion to 02. increase the overall amount of oxygen. can be achieved in the presence of the CO combustion promoter of the present invention. The improved CO burn rate eliminates large excess emptying as done in the prior art. There is no need to operate with enthusiasm.

Example 1 (prior art) The following examples describe operating conditions for circulating fluidized bed boiler installations reported in the literature. represent the case. The device is a bit generic in that the feed is wood chips rather than coal Therefore, sulfur scavenging sorbents are not required to meet SOx emission limits. There was no. Solid particulate matter is necessary for proper operation of the device and therefore Sand was added for heat transfer, proper bed fluidization, etc. Installation of two CFB boilers Report the total: Babcock-Ultra Powered Powered) CFB Boiler and Energy Factors (Ener gy Factors) CFB boiler. Table 1 shows the circulating Fluidized Bed Technology (Circu-1ating Fl uidized Bed Technology), n page 354 , F. Belin (F, Be1in), D. E. James (D, E.

J arBes), Dee Jay Walker (D, J, Walker), R.J. Warrick's "Waste Wood" Compassion in Circulating Fluidized Bed Waste'wVood Combustion in C ircu-rating Fluidized Bed Boilers) J by.

Table 1 Babcock and Wilcox CF B boiler performance data Tapabukonoku Ultra Power Energy Factors Keiichi several companies! Nobu! !　 Design value Test value tfi negative? W (total) III 27.5 28.3 19. 5 19.6 Maximum steam flow rate (MCR) kg/s 27.6 26.4 20. 7 21.51000 lb/hr 21g, 6 209.0 164.0 1 70.8 Steam pressure bar 86.2 85.9 87.5 87.2 psi g 1250 1245 1270 1265 Water vapor temperature 'C5135115 13509'F 955 951 955 949 Water supply temperature 'CI47 15 1 186 196’F 296 303 367 385 Gas/air temperature Furnace outlet gas 'C857873849823'F 1575 1603 156 0 1514 air heater Outgoing flue gas 'C135128150152''F 275 263 302 305 air heater Outgoing air 'C209203191189'F 408 398 375 37 2 Heat efficiency (HUV standard) % 78.8 79.81 81.3 81.28 Fuel Water content % 40.4 38.0 30.0 46.4 Carbon loss after burning % 1 ．． 2. 01 1.2 0.09 Excess air % 16 24 21 191st/ Overfire air division % 50150 5015 0 - 60/40 25/75 Emission limit at MCR Limit NOx lb/10’Btu O, 158, 155, 1?5 0.110Co lb/10’Btu0.158. 025. 218 0.100 implementation bear (book invention) In this example, 1 pp The changes caused by adding m of platinum are evaluated.

Platinum has a particle density of 2.0-2.5 g/ml or more and a particle density of 500 μm. Add as pt on a silica/alumina support with average particle size. these are, Can be formed by spray drying (marumerizing), explosive formation, oil droplets, etc. . Alumina or silica or silica/alumina are preferred. The accelerator is a conventional Catalysts similar to those used in FCC catalysts, but used in FCC equipment It's a little bigger and a little heavier. The accelerator contains 0.1% by weight of platinum in the CFB. Addition of 1% by weight of additive to the amount retained in circulation results in 1 ppm platinum.

Other changes that occur when operating the equipment listed in Table 1 are This means that the output will decrease significantly.

Preferably reduce excess air and/or adjust the fuel addition rate to the heat exchange capacity of the device. increase to the limit.

In designing new equipment, combustion areas, cyclones, and air blowers ( (blowers) should be small because the amount of air allowed by the invention is reduced. It needs to be measured and manufactured.

having a terminal velocity of at least 80% to 120% of the design superficial gas velocity in the CFB; Preferably, a co combustion promoter is used. Rapid settling C○ Combustion accelerator is CF H only limits circulation and the concentration of circulating particles that the device retains , provides an apparently large concentration in CFH.

Fast-settling co combustion accelerators rarely go to the CFB cyclone and essentially 100% recovery.

Although the accelerator carrier is large and strong, it has a very long life in CFB equipment. has. As the promoter passes through a locally hot region at the bottom of the high velocity fluidized bed combustion zone, If the accelerator remains suspended above this region, degradation due to CO combustion will occur. There are almost no

FIG 2 Supplementary vl floor desi' first cum violet or duck NOx i fraud fat 1111°゛s0z171 function L Rema/) NOJ Anus (partial FIG, 3) Baojing road inspector report 1mjllll11゜+ml A*ILll+,. -h-pcTzus 901 00862 International Search Report

Claims (9)

[Claims] 1. High-velocity flow of granules with particle diameters of at least the majority greater than 100 μm contact with an oxygen-containing gas in a generally vertical combustion apparatus comprising a bed The flue gas discharged from the top of the combustion device by burning the carbon-containing material / a circulating fluidized bed combustion zone producing a particulate stream, the flue gas stream is a flue gas, a particle diameter of 100 μm or less and a particle size of 100 to 400 μm. This flue gas stream comprises circulating particles with an average particle size in the range of μm. The ream is passed through a separation means to remove at least a majority of the particles between 100 and 400 μm. Circulating flow such that the flue is recovered from the gas and recycled to the circulating fluidized bed combustion zone. In the bed combustion area, Pt, Pd, Ir, Rh, Os and their compounds 0.001 to 10 by weight of circulating particles of accelerator selected from the group of Add CO combustion promoter to the combustor in an amount equal to 0 ppm by weight, between 400 and 120 ppm. Improved by the presence of an accelerator in the carrier with an average particle diameter in the range of 0 μm The way it was done. 2. The CO combustion promoter is platinum, present in an amount equal to 0.01 to 50 ppm by weight. A method according to claim 1. 3. The amount of CO combustion promoter present is between 0.05 and 10 ppm by weight of platinum CO acid. The method according to claim 1, which corresponds to the activation activity. 4. 2. The method of claim 1, wherein the CO combustion promoter comprises Pt/Rh. 5. CO combustion promoters have average particle diameters ranging from 500 to 1000 μm and small Claim 1 impregnated in a porous carrier having a surface area of at least 20n2/g The method described in Section 1. 6. The CO combustion promoter has an average equivalent particle diameter ranging from 550 to 750 μm, 1.5 Support with an average particle density of ~2.5 g/cc and a surface area of 50 m2/g or more A method according to claim 1, present above. 7. CO combustion promoters include silica, alumina, silica/alumina, kaolin and A method according to claim 1, wherein the method is on a carrier selected from a mixture of these. 8. CO combustion promoters are promoter metals or gold that have a promoter-poor shell portion. 2. A method according to claim 1, comprising a core enriched in genus compounds. 9. Carbon-containing materials contain sulfur and nitrogen impurities, and the combustion of carbonaceous materials is a high-speed flow Occurs in the lower part of the floor and contains carbon monoxide, carbon dioxide, SOx and NOx 2. A method according to claim 1, wherein a dilute phase fluidized bed is formed.