CN102443445B - Process and device for continuously gasifying biomass and simultaneously removing tar in moving bed - Google Patents

Abstract

The invention provides a process and a device for continuously gasifying a biomass and simultaneously removing tar in a moving bed. The process comprises the following steps: in a gravity moving bed, adding raw materials from top at a certain speed, and controllably introducing air at the upper furnace mouth, middle charring section and lower recrudescence decoking section simultaneously; and continuously generating activated carbon which is discharged from the bottom at a certain speed. The device suitable for the method is a tube bank type moving bed gasifying and tar removing furnace, wherein a furnace core is arranged in the furnace; rows of reaction tubes (13) are assembled by stacking uniquely designed specially shaped refractory bricks; and under the reaction tubes (13), carbon cooling tubes (17) are connected, and a multi-point continuous equivalent carbon discharging device is connected. According to the process and the device provided by the invention, tar content is low, no waste water is discharged, activated carbon is by-produced, and production cost is greatly reduced.

Description

Biomass moving bed continuous gasification is removed technique and the equipment of tar simultaneously

Technical field

The present invention relates to gasifying biomass and charcoal, activating technology field, is remove tar removing simultaneously and realize technique and the equipment that charcoal activates about biomass continuous gasification.

background technology

Biomass energy is due to low-carbon (LC) and renewablely day by day by contemporary society, paid attention to, and wherein biomass pyrogenation gasification is manufactured fuel gas or is further used for generating, is an important channel.Existing gasifying biomass processing unit can be divided into seven kinds of type of furnaces of two classes substantially, and the one, fixed bed, comprises downdraft fixed-bed gasification furnace, updraft type fixed-bed gasification furnace, crossdraft fixed-bed gasification furnace, happy formula fixed-bed gasification furnace; The 2nd, fluidized-bed, comprises single fluidized-bed gasification furnace, circle fluidized-bed gasification furnace, double-fluidized-bed vapourizing furnace.The above-mentioned type of furnace is respectively had its own the scope of application, and fluidized-bed is adapted to powdery and fine-grannular raw material, and fixed bed is adapted to coarse grain shape and sheet, lumpy material.

One of their common shortcoming is that the coal-tar middle oil content of the fuel gas of output is too high.Tar problem is to affect the bottleneck that these fuel gas are used, and tar can stop up air delivering pipeline, stops up the sparking plug of engine or the fuel gas hole of burner, and the cylinder that even bonds, cannot normally move generator and air feed equipment.Therefore, above-mentioned fuel gas also needs to remove the processing (conventionally referred to as decoking, lower same) of tar removing.What existing decoking generally adopted is wet type decoking method.Wet type decoking method makes fuel gas and the cooling of spray water counter current contact in fact exactly in decoking equipment, and the tar that boiling point is high is condensed sneaks in spray water, and then these waste water are carried out to tar separation and purification.This method facility investment is large, troublesome poeration, and labor condition is poor, and water consumption is many, and running cost is high, easily causes secondary pollution, is the one of the main reasons that biomass gasification technology is difficult to apply.In view of this, many countries are all carrying out the technological development of dry dry type high-temperature catalytic decoking in the world, the principle adopting is basic identical, it is catalytic pyrolysis, the catalyzer using has rhombspar, charcoal and nickel-base catalyst etc., and nickel-base catalyst activity is high, temperature of reaction is low, but vulnerable to pollution and losing efficacy, and price is high, lack practicality; Rhombspar needs quantity many, obtains prior moulding, uses rear regeneration, and will heat, and not only troublesome poeration also will increase energy consumption; Comparatively reasonably to adopt charcoal to make catalyzer, someone does overtesting, under the condition of 1050 ℃ of cracking temperatures, decoking rate can reach 92% (< < renewable energy source > > 2005, № 5, p30～34.), but this method needs the special pyrolyzer of building, investment is large, operation is long, and because charcoal in reaction process is not only catalysis, self be also vaporized and constantly consume, at 900～1000 ℃ of temperature, supplementing charcoal and deashing becomes new difficult point.

Two of the shortcoming that they are common is when producing fuel gas, to produce charcoal or gac.This is that feature due to their technology and equipments itself determines, reason is that above-mentioned 7 kinds of type of furnaces all cannot be determined the residence time of raw material in stove exactly, does not also take out means or the device of pyrocarbon.

For fixed-bed gasification furnace, also have other obvious shortcomings, that can enumerate has: the one, and the air-flow skewness of the bed of material in stove, and then cause that the furnace temperature difference on same level is large, there is so-called " partially burning "; The 2nd, the bed of material easily produces arch formation, need to manually disclose stove and just can make stove normally move, and operability significantly reduces.Due to like this, single stove scale of fixed bed is difficult to expand, the maximum stove having used at present, and its internal diameter is no more than 1.6 meters, and gasification sectional area is no more than 2 square metres.

summary of the invention

One of object of the present invention is to provide a kind of gasification continuously and carries out again the technique of dry type high-temperature catalytic decoking simultaneously; Two of object is to provide a kind of and equipment this process matching, is referred to as " pipe row formula moving-bed gasification is except coke oven "; Three of object is to utilize this type of furnace not only to manufacture fuel gas (calling combustion gas in the following text) but also by-product gac.The inventor thinks, existing fixed bed and the why high basic reason of fluidized bed gasifying process tar content are due to equipment limitation itself, the cause that can not process by the regular hour again in stove under enough high temperature the combustion gas generating, the technology and equipment that only changes just can tackle the problem at its root, Here it is adopts mobile pool furnace, and the tar in the combustion gas that not only makes gasifying biomass but also make to generate is subject to katalysis and cracking.The solution of the present invention is in gravity moving-bed, biomass material constantly adds from top by certain speed, meanwhile, the position of three different heights in upper, middle and lower, controlledly send into or suck a certain amount of air, the high-temperature fuel gas generating in stove is from drawing continuously lower than the gas outlet of next air intlet, by one-level indirect heat exchanger, reclaim sensible heat successively, secondary, three grades of indirect heat exchanger cooling and filtering type and adsorption type coke removing appts. degree of depth decoking, then send into gas storage holder; The gac generating is continuously discharged from bottom by certain speed.

The equipment of implementing above-mentioned technique is mainly that moving-bed gasification removes coke oven.This stove can be single tube furnace of circular, square and arbitrary section, but due to single tube stove cross section greatly to a certain extent after, air-flow is just difficult to be evenly distributed, thereby has limited its mass-producing application.The inventor has drawn the advantage of piling up assembly type carbon activation furnace, through research trial repeatedly, has created the brand-new type of furnace " pipe row moving-bed gasification is except coke oven " adapting to above-mentioned gasification decoking.This stove belongs to vertical gravity moving-bed, except the standby furnace cradle of existing gasification stove, stove outer covering, thermal insulation layer and furnace wall, combustion chamber is set especially, this combustion chamber is piled up the reaction tubes (13) that is assembled into several rows of rows of proper alignment by the Idiotype refractory brick of several unique design, its lower charcoal cooling tube (17) that connects, charcoal cooling tube (17) below connects " multiple spot continuous and quantitative goes out charcoal device "; The outer stove interior wall (3) that encloses of combustion chamber, the outer thermal insulation layer (2) that is with of stove interior wall (3), the periphery of thermal insulation layer (2) is stove outer covering (1); In reaction tubes (13), be followed successively by from top to bottom dryer section, pre-charing section, charing burning zone, reduction and gaseous section, fire just cold section of decoking section, charcoal again, fire door (4) is as one-level blast inlet, between pre-charing section and charing burning zone, reduction and gaseous section with fire again between decoking section, be equipped with straight gas passage (12) and horizontal gas passage (11) between cold section at the beginning of firing decoking section and charcoal again, respectively with the corresponding mutual UNICOM of (10) three grades of blast inlets of secondary blast inlet (14), gas outlet (15).

During stove operation, first in stove, fill it up with charcoal, then with firing tools, the charcoal on fire door surface is lighted, then start induced draft fan, due to air intake, charcoal burns more prosperous and more prosperous, starts " multiple spot continuous and quantitative goes out charcoal device " in good time, and in stove, charcoal relies on action of gravity to move down gradually, burning red charcoal layer baking combustion chamber brick constantly raises temperature in stove, meanwhile, fire door starts constantly to add raw material wood chip, makes material level keep certain level.First the wood chip that enters stove enters dryer section, after being heated, make moisture evaporation, then enter temperature and be about the pre-charing section of 180～250 ℃, start pyrolysis, there are some inflammable gass to discharge, with after the air mixed sucking, produce thermopositive reaction, material temperature is further raise, while reaching 300 ℃, start main pyrolysis, produce the secondary air generating unit divided combustion of a large amount of inflammable gass and importing, make furnace temperature rise get Geng Gao, charing is more violent, this stage is called charing burning zone, bottom at this section, furnace temperature generally can reach and be controlled at 1000 ℃, at this temperature, due to the violent polycondensation aromizing of material organism, there is for example hydrogen of a large amount of gas, methane, carbon monoxide, water vapour and carbonic acid gas continue to be released, along with constantly moving down of the bed of material and gas, enter reduction and gaseous section, carbonic acid gas in gas and water vapor react with scorching hot charcoal layer generation water-gas again, it is main more combustion gas that hydrogen and carbon monoxide are take in formation, but due in thermal cracking processes above, be accompanied by some pair of reaction, can for example, with a small amount of " tar " and potential tar material (benzene homologue in combustion gas, naphthalene, anthracene, luxuriant and rich with fragrance etc.), because water-gasization reaction is thermo-negative reaction, the temperature of charcoal body drops to 700 ℃ of left and right very soon, in the tradition type of furnace, these burnt oily substances are difficult to be decomposed, often with combustion gas, discharge, in this type of furnace, import again three grades of air firing again decoking section, combustion gas continues to move down

During to this section, another generating unit divided combustion, furnace temperature and charcoal temperature are elevated to 1000 ℃ again, and at this temperature, charcoal body has good catalytic activity, makes tar and burnt oily substance be cracked into rapidly lower-molecular substance, reaches the object of decoking.And, under this hot conditions, the carbonic acid gas in combustion gas and water vapor also can with charcoal body generation priming reaction, when continue generating carbon monoxide and hydrogen, charcoal body is become have the low and middle-grade gacs of certain adsorptive power.

From the mode of decoking, the invention belongs to independent decoking in stove, and in existing stove, to mix decoking and compare, its advantage is not need extra catalyst, has got rid of the operation of interpolation, separation and regenerated catalyst; The catalyzer using from decoking, the present invention belongs to again charcoal catalysis decoking in stove, compares with the outer charcoal catalysis decoking separately of existing stove, and its advantage is simplified apparatus, the saving energy and handled easily; The advantage that the present invention is larger is environmental protection, compares with existing wet method decoking, owing to not needing spray, bubble-cap or Venturi gas washing, does not just have waste water and produces; It is by-product gac that the present invention also has unique advantage, existing gasification process and the type of furnace, and the solid materials of discharge, normally, with the lime-ash of carbon powder, the present invention but can discharge gac continuously, and economy significantly improves.

Accompanying drawing explanation

Fig. 1 represents that the present invention gasifies except the longitudinal diagram of coke oven along horizontal axis, and Fig. 2 represents the longitudinal diagram of the axis A-A in Gai Luyanliao road (19), but its left half figure combustion chamber part represent along this stove directly to the sectional view of axis.In above-mentioned figure: (1) stove outer covering, (2) thermal insulation layer, (3) stove interior wall, (4) fire door, (5) skewback brick, (6) straight plate brick, (7) opening brick, (8) swash plate brick, (9) transverse slat brick, (10) secondary blast inlet, (11) horizontal gas passage, (12) straight gas passage, (13) reaction tubes, (14) three grades of blast inlets, (15) gas outlet, (16) furnace cradle, (17) charcoal cooling tube, (18) turn takes off discharger, (19) spiral discharging device, (20) star discharger.

Fig. 3 is the stereographic map of straight plate brick (6), and Fig. 4 is that stereographic map, Fig. 5 of transverse slat brick (9) is that stereographic map, Fig. 6 of skewback brick (5) is that stereographic map, Fig. 7 of swash plate brick (8) is the stereographic map of opening brick (7).

In Fig. 1, Fig. 2, fine grid line section represents Idiotype combustion chamber brick, dredges mesh lines section and represents general fire brick, and pit shape section represents thermal insulation layer.

Embodiment

Method of the present invention need to could be implemented by concrete vapourizing furnace, although the more than a kind of pattern of enforceable stove, the special quarl of use unique design as shown in Figure 1 and Figure 2 that proper is is piled up " pipe row moving-bed gasification is except coke oven " that is assembled into combustion chamber.The combustion chamber brick of this stove can use straight plate brick (6) as shown in Fig. 3,4,5,6,7, transverse slat brick (9), skewback brick (5), swash plate brick (8), opening brick (7) the Idiotype refractory brick of totally five kinds of unique design pile up and be assembled into several rows of rows of reaction tubes (13), the straight rectangular thick plate-like of plate brick (6), the upper side of its " long * thick " has a semicircle groove, the downside of " long * thick " has a semicircle fin, and two broadsides of the upper side of " long * wide " respectively have an arcuation lug, nib, the rectangular thick plate-like of transverse slat brick (9), the upper side of its " long * thick " has a semicircle groove, and the downside of " long * thick " has a semicircle fin, and respectively there is a semicircle groove two sides of " wide * thick ", the rectangular trapezoidal thick plate-like of swash plate brick (8), there is a semicircle groove side on its " long base * thick ", " there is a semicircle lug, nib ×Hou” side, short base, there are a semicircle lug, nib and a semicircle groove in " right angle waist * wide " side, and there is a semicircle groove " oblique waist * wide " side, the rectangular trapezoidal strip of skewback brick (5), " there is a semicircle lug, nib ×Chang” side, long base near oblique that side of waist, and respectively there is a semicircle lug, nib " tiltedly waist * length " side containing oblique waist in interior both sides for it, opening brick (7) is " pistol " shape strip, and it " robs mouth ", and there is a semicircle lug, nib side, and " robbing handle " outer side has a semicircle groove near " gun barrel " side, while building combustion chamber by laying bricks or stones, from furnace cradle (16) up, the first layer, straight plate brick (6) is in a row placed, transverse slat brick (9) is horizontal to be inserted between the straight plate brick (6) that two rows are adjacent, and the groove of self side is blocked to the fin of upper adjacent two straight plate bricks (6) side of same row, the second layer, skewback brick (5) is in a row placed, swash plate brick (8) is horizontal to be inserted between the skewback brick (5) that two rows are adjacent, and the groove of self side is blocked to the fin of upper adjacent two skewback bricks (5) side of same row, the 3rd layer, opening brick (7) is in a row placed, transverse slat brick (9) is horizontal to be inserted between the opening brick that two rows are adjacent (7), and the groove of self side is blocked to the fin of upper adjacent two opening bricks (7) side of same row, the 4th layer is risen by above-mentioned masonry way repetition 3～4 times, each opening brick (7) is linked to be straight gas passage (12), the inner furnace wall core of tightly sitting around a fire, and be no less than three grades of horizontal gas passages (11) that are communicated with these straight gas passages (12) with setting on above-mentioned straight gas passage (12) same level face, and the horizontal gas passage of upper secondary (11) is communicated with the blast inlet (10) of stove, the horizontal gas passage of next stage (11) is communicated with the gas outlet (15) of stove.

" multiple spot waits and measures charcoal device continuously " that this stove connects is quite large to the operating influence of stove, so-called " multiple spot waits and measures charcoal continuously " is to make all simultaneous equals and go out continuously charcoal of each side reaction pipe, must adopt special turning to take off discharger (18), under it, connect again spiral discharging device (19) and star discharger (20).

The filtering type of aforementioned indication and adsorption type coke removing appts., more satisfactory is the charcoal absorption strainer that has the two function concurrently.

Claims (3)

1. the biomass moving bed continuous gasification technique of tar removing simultaneously, it is characterized in that: in gravity moving-bed, biomass material constantly adds from top by certain speed, rely on action of gravity to move down gradually, form from top to bottom dryer section, pre-charing section, charing burning zone, reduction and gaseous section, fire again decoking section, just cold section of charcoal, meanwhile, at top fire door, middle part charing burning zone, bottom is fired decoking section again, controlledly import a certain amount of air, the high-temperature fuel gas generating in stove is from drawing continuously lower than the gas outlet of next air intlet, successively by reclaiming the one-level indirect heat exchanger of sensible heat, the secondary of cooling use, filtering type and adsorption type coke removing appts. that three grades of indirect heat exchangers and degree of depth tar removing are used, then send into gas storage holder, the gac generating is continuously discharged from bottom by certain speed.

2. the biomass moving bed continuous gasification equipment of tar removing simultaneously, it is characterized in that: pipe row formula moving-bed gasification is except coke oven, combustion chamber is set in stove, this combustion chamber piles up by some Idiotype refractory brick such as straight plate brick (6), transverse slat brick (9), skewback brick (5), swash plate brick (8), opening bricks (7) reaction tubes (13) that is assembled into several rows of rows of proper alignment, its lower charcoal cooling tube (17) that connects, charcoal cooling tube (17) below connects " multiple spot waits and measures charcoal device continuously ", and " multiple spot waits and measures charcoal continuously " is to make all simultaneous equals and go out continuously charcoal of each side reaction pipe, in reaction tubes (13), be followed successively by from top to bottom dryer section, pre-charing section, charing burning zone, reduction and gaseous section, fire just cold section of decoking section, charcoal again, between pre-charing section and charing burning zone, reduction and gaseous section with fire again between decoking section, be equipped with straight gas passage (12) and horizontal gas passage (11) between cold section at the beginning of firing decoking section and charcoal again, respectively with the corresponding mutual UNICOM of secondary blast inlet (10), three grades of blast inlets (14), gas outlet (15), the straight rectangular thick plate-like of plate brick (6), the upper side of its " long * thick " has a semicircle groove, and the downside of " long * thick " has a semicircle fin, and two broadsides of the upper side of " long * wide " respectively have an arcuation lug, nib, the rectangular thick plate-like of transverse slat brick (9), the upper side of its " long * thick " has a semicircle groove, and the downside of " long * thick " has a semicircle fin, and respectively there is a semicircle groove two sides of " wide * thick ", the rectangular trapezoidal thick plate-like of swash plate brick (8), there is a semicircle groove side on its " long base * thick ", " there is a semicircle lug, nib ×Hou” side, short base, there are a semicircle lug, nib and a semicircle groove in " right angle waist * wide " side, and there is a semicircle groove " oblique waist * wide " side, the rectangular trapezoidal strip of skewback brick (5), " there is a semicircle lug, nib ×Chang” side, long base near oblique that side of waist, and respectively there is a semicircle lug, nib " tiltedly waist * length " side containing oblique waist in interior both sides for it, opening brick (7) is " pistol " shape strip, and there is a semicircle lug, nib its " muzzle " this side, and " robbing handle " outer side has a semicircle groove near " gun barrel " side, the first layer, straight plate brick (6) is in a row placed, transverse slat brick (9) is horizontal to be inserted between the straight plate brick (6) that two rows are adjacent, and the groove of self side is blocked to the fin of upper adjacent two straight plate bricks (6) side of same row, the second layer, skewback brick (5) is in a row placed, swash plate brick (8) is horizontal to be inserted between the skewback brick (5) that two rows are adjacent, and the groove of self side is blocked to the fin of upper adjacent two skewback bricks (5) side of same row, the 3rd layer, opening brick (7) is in a row placed, transverse slat brick (9) is horizontal to be inserted between the opening brick that two rows are adjacent (7), and the groove of self side is blocked to the fin of upper adjacent two opening bricks (7) side of same row, the 4th layer is risen by above-mentioned masonry way repetition 3～4 times, each opening brick (7) is linked to be straight gas passage (12), the inner furnace wall core of tightly sitting around a fire, and be no less than three grades of horizontal gas passages (11) that are communicated with these straight gas passages (12) with setting on above-mentioned straight gas passage (12) same level face, and the horizontal gas passage of upper secondary (11) is communicated with the blast inlet (10) of stove, the horizontal gas passage of next stage (11) is communicated with the gas outlet (15) of stove.

3. the biomass moving bed continuous gasification according to claim 2 equipment of tar removing simultaneously, is characterized in that: " multiple spot continuous and quantitative goes out charcoal device " comprises to turn and take off discharger (18), spiral discharging device (19) and star discharger (20).

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