WO2015192609A1

WO2015192609A1 - Continuous wood charring and gasifying method and apparatus

Info

Publication number: WO2015192609A1
Application number: PCT/CN2014/092823
Authority: WO
Inventors: 胡福昌; 王正郁
Original assignee: 杭州富来森科技有限公司
Priority date: 2014-06-19
Filing date: 2014-12-02
Publication date: 2015-12-23
Also published as: CN104804752A

Abstract

A continuous wood charring and gasifying method and apparatus. Wood raw materials M are continuously fed from the top of the apparatus at a certain speed, and non-gasified solid charcoal C is continuously discharged from the bottom of the apparatus at a certain speed. Meanwhile, a certain amount of air A is dispersedly guided into the apparatus from the top in a controlled manner, and high-temperature fuel gas G generated in a bed layer is continuously guided out from the lower part of the apparatus by using a high-temperature draft fan (17) and is then pressurized and conveyed into a combustor for combustion. The apparatus is referred to as an "environmental-friendly coal-gas co-production charring furnace" for short. A water-cooling bottom plate (2) is arranged on a furnace bracket (1). A fuel gas guide-out section (3) with a multi-ring-gap gas guide function, a furnace housing (4) and a smoke-suppression furnace opening cover (5) are sequentially connected to the upper part of the water-cooling bottom plate (2). A charcoal cooling pipe (6) is connected to the lower part of the water-cooling bottom plate (2). Refractory bricks (7) and heat preservation layers (8) are built on the inner side of the charcoal cooling pipe (6). A kick-out device (9) working in a multipoint synchronous balanced and continuous mode is connected to the lower part of the charcoal cooling pipe (6). A helical feeder (10) and a star-shaped discharging valve (11) are sequentially connected to the lower part of the kick-out device (9). The apparatus has the advantages of being easy to manufacture, low in investment, convenient to operate and energy-saving and producing no waste gas, no waste water and no waste residues.

Description

Method and apparatus for continuous carbonization and gasification of wood

Technical field

The invention relates to the technical field of wood pyrolysis carbonization and gasification, and relates to a process and equipment for continuous carbonization and gasification of wood materials in a moving bed.

Background technique

Wood pyrolysis is a long-established industry. The wood and its residues of harvesting, tending and processing (called “three remnants”) are used as raw materials. After dicing and drying, it is sent to the dry distillation kettle to prevent air heating. The hemicellulose, cellulose and lignin in the raw material are cracked to produce products such as wood gas, wood vinegar, wood tar and charcoal. The commonly used equipments are externally heated vehicle-type retort, and the second is a vertical internal heat-drying kettle. The former is intermittent (batch) production, and the latter is a moving bed continuous production, but the feeding and carbon removal are carried out periodically and quantitatively. . In the vertical internal heat dry distillation kettle, the feeding device is composed of a feeding hopper, a gate valve, a round pipe, an annular water seal and a triangular cover; the discharging device is composed of a needle valve and two gate valves; the furnace body is a cylinder In the shape, two conical funnels and a cone are arranged in between, and the conical funnel forms an annular gap (annulus) with the inner wall of the furnace to allow gas to flow, the upper annulus acts as a heat carrier gas inlet, and the lower annulus acts as a heat exchange. The outlet of the gas; the cone is placed above the carbon removal device to act as a charcoal. During the operation, when the feed and the carbon are discharged at a certain time interval, the raw material gradually moves down in the furnace, first enters the pyrolysis section, is heated by the heat carrier gas flowing from the bottom to the top, continues to heat up, and sequentially dried. Pre-charging, carbonization and calcination, continue to move down and then enter the cooling section, heat exchange with the bottom-up cold gas, the temperature of the carbon body is reduced to below 50 ° C, and discharged through the carbon removal device. The advantage of the furnace is that the output of charcoal is large, the strength is high, the degree of mechanization of operation is high, and no additional energy is needed in normal operation. The disadvantage is that the furnace structure is complicated, the heat carrier gas and the cooling gas need to be recycled, and the supporting system is large and the investment is high. The operation and maintenance requirements are high, and it is difficult to use the small pieces of raw materials in the “three remnants”. It is only suitable for large-scale production in resource-rich areas, and it is difficult to promote them according to local conditions.

Summary of the invention

One of the objects of the present invention is to provide a process which can continuously perform carbonization and gasification; the second purpose is to provide a device which is most suitable for the process; the third purpose is to use the furnace to produce both high quality charcoal and by-product high temperature. Gas, used for power generation or as a source of other heat.

The process of the present invention is that in the gravity moving bed F shown in FIG. 1, the wood material M is continuously added from the top at a constant speed, and the ungasified solid carbon C is continuously discharged from the bottom at a constant speed; at the same time; At the top, a certain amount of air A is controlled to be dispersed and introduced, and the high-temperature gas G generated in the bed flows downstream with the particulate material. After the lower gas-solid separation, the high-temperature induced draft fan (17) continuously leads and increases from the middle and lower portions. Press it and send it to the burner for combustion.

The equipment proposed for implementing the above process is to create a multi-point synchronous equalization continuous discharge aspirating internal heat moving bed carbonization and gasification furnace, which is referred to as “carbon gas cogeneration environmentally friendly carbonization furnace”. It is a single furnace with a rectangular cross section. Since the single-furnace furnace has a large cross-section to a certain extent, the airflow is difficult to distribute evenly, which limits its large-scale application. For this reason, the inventors have uniquely designed a gas-derived section having a plurality of annular gaps while conducting gas. Annular air guiding section) (3), double-shell water-cooled furnace floor (referred to as water-cooled floor) (2) and smoke-proofing furnace mouth cover (inhibition of smoke-proof furnace mouth) Cover) (5). The multi-ring gap gas guide section (3) may have a single-layer structure, but it is preferably a double-shell water-cooled structure. The main configuration of the furnace is: a water-cooled bottom plate (2) is placed on the furnace support (1), and a multi-ring gap gas guide section (3), a furnace shell (4) and a smoke suppression furnace mouth cover (5) are sequentially connected at the upper end thereof. The lower end is connected with a charcoal cooling pipe (6), the inner side of which is refractory brick (7) and the heat insulating layer (8), and the lower end of the charcoal cooling pipe (6) is connected with a multi-point synchronous equalizing continuous feeder (referred to as a feeder) (9) Then, the screw feeder (10) and the star discharge valve (11) are connected in turn; the opposite sides of the multi-ring gap gas guiding section (3) are provided with a suction nozzle (12) and a cooling water inlet (13). And the cooling water outlet (15), the suction nozzle (12) is connected with the air inlet of the high temperature induced draft fan (17); the water inlet (14) and the water outlet (16) are provided on opposite sides of the water cooled floor (2) ).

Principles and methods of operation. When the furnace is running, first add the bottom charcoal in the furnace, then start the high temperature induced draft fan (17), and then use the ignition tool to ignite the charcoal on the surface of the furnace mouth. Due to the air inhalation, the charcoal is more and more popular, and the feeder is started at the right time. (9), the charcoal in the furnace gradually moves down by gravity, and the red carbon layer bakes the furnace core brick, so that the temperature in the furnace is continuously increased. At the same time, the furnace mouth begins to continuously add the raw wood chips M, and the material level is Keep a certain level. The wood chips entering the furnace first enter the drying section, and after evaporation, the water is evaporated, and then enters the pre-carbonization section at a temperature of about 180-250 ° C to start pyrolysis. Some flammable gases are released and mixed with the inhaled air to generate an exothermic reaction. The temperature of the material is further increased. When the temperature reaches 300 ° C, the main carbonization starts, and a large amount of combustible gas containing methane, hydrogen and carbon monoxide is generated, and is generated while being introduced into the air to be burned, so that the furnace temperature rises higher and the carbonization is further increased. Severe, this stage is called carbonization combustion section. In this section, the furnace temperature can generally be reached and controlled at 750-850 °C. At this temperature, the carbon layer and the gas flow downstream, and continue to move down, and the charcoal is further calcined. The reduction reaction of the gas occurs, and part of the carbon dioxide and water vapor are converted into carbon monoxide and hydrogen, which increases the calorific value of the gas. However, due to some side reactions in the above thermal cracking process, the gas will carry a small amount of "tar" and potential tar substances (such as benzene homologues, naphthalene, anthracene, phenanthrene, etc.). Since the reduction reaction is an endothermic reaction, the temperature of the charcoal and the gas gas rapidly drops below 700 ° C while continuing to move downward, and further decreases when entering the multi-ring gap gas guiding section (3), and simultaneously performs gas-solid separation. The high-temperature gas G is extracted from the respective annular gaps through the suction nozzle (12) by the high-temperature induced draft fan (17), and is pressurized in the induced draft fan and sent to the burner for combustion; the charcoal C continues to move down to the water-cooled bottom plate (2) And the charcoal cooling pipe (4), after cooling to normal temperature, is discharged through the feeder (9), the screw feeder (10) and the star discharge valve (11).

The invention has the advantages that the first is that the equipment is easy to process and manufacture, and the investment is low; the second is continuous operation, labor saving and convenient operation; the third is that the production process does not need additional fuel, energy is used efficiently, and the production cost is reduced; , waste water and waste gas Emissions, environmental protection advantages are obvious; Fifth, small materials and small materials can be used, factories should be built according to local conditions, and resources should be fully utilized.

DRAWINGS

Fig. 1 is a front cross-sectional view showing a "carbon gas co-production environment-friendly carbonization furnace", Fig. 2 is a cross-sectional view taken along line A-A of Fig. 1, and Fig. 3 is a view showing a process principle of the present invention. In the above figures: (1) furnace support, (2) water-cooled floor, (3) multi-ring gap gas guide, (4) furnace shell, (5) smoke suppression furnace cover, (6) charcoal cooling pipe, ( 7) refractory brick, (8) insulation layer, (9) material feeder, (10) screw feeder, (11) star discharge valve, (12) suction pipe port, (13) multi-ring gap gas guide section Cooling water inlet, (14) cooling water inlet of water-cooled floor, (15) cooling water outlet of multi-ring gap gas guide, (16) cooling water outlet of water-cooled floor, (17) high-temperature induced draft fan.

detailed description

A "carbon gas co-production environmentally friendly carbonization furnace" as shown in Fig. 1 and Fig. 2, the net size of the furnace: length L = 3.8 m, width = 2.6 m, depth = 1.4 m. The multi-ring gap gas guide section (3) is a double-shell water-cooled structure. The refractory brick adopts clay-type standard brick, the thermal insulation layer adopts expanded perlite refractory concrete; the furnace support (1) adopts steel pipe and channel steel; water-cooled bottom plate (2), multi-ring gap gas guide section (3), furnace shell (4) The smoke suppression furnace mouth cover (5) charcoal cooling pipe (6) and the screw feeder (10) are all made of 6mm steel plate; the star discharge valve (11) is a commercial product, cast steel manufacturing; multi-point synchronization The balanced continuous feeder (9) adopts the "multi-point synchronous continuous discharger" of the Chinese patent CN 201120450680.9. Raw wood chips: particle size 20 ~ 60mm, maximum ≤ 80mm, minimum ≥ 10mm, moisture content ≤ 20%. The carbon speed is controlled by adjusting the rotation speed of the material feeder (9), the temperature of the carbonization combustion section is maintained at 750-800 ° C; the cooling water temperature: the inlet water ≤ 25 ° C, the effluent ≤ 60 ° C; the continuous operation for 5 days, the average daily carbon 2.4t, gas output about 1000m ³ /h, carbon production rate ≈18% (dry basis), gas production rate ≈1.8m ³ /kg (dry basis), charcoal fixed carbon content ≥88% (dry basis), charcoal The calorific value is 28000 to 32000 kJ/kg, and the calorific value of the gas is 4000 to 4200 kJ/m ³ .

Claims

A method for continuously carbonizing and gasifying wood, characterized in that: in the gravity moving bed F, the wood material M is continuously added from the top at a certain speed, and the ungasified solid carbon C is continuously discharged from the bottom at a certain speed; At the same time, a certain amount of air A is controlled to be dispersed and introduced at the top, and the high-temperature gas G generated in the bed flows along with the particulate material, and is continuously drawn by the high-temperature induced draft fan (17) after the gas-solid separation in the middle and lower portions. After being compressed, it is sent to the burner for combustion.
A vertical moving bed wood continuous carbonization and gasification device, characterized in that: the furnace section is rectangular, a water-cooled bottom plate (2) is placed on the furnace support (1), and the upper end is connected with a plurality of annular gap gas guiding sections (3), Furnace shell (4) and smoke suppression furnace mouth cover (5), the lower end of which is connected with charcoal cooling pipe (6), the inner side of which is refractory brick (7) and the heat insulating layer (8); the lower end of the charcoal cooling pipe (6) is connected The point synchronously equalizes the continuous feeder (9), and then connects the screw feeder (10) and the star discharge valve (11) in turn; and the suction nozzles are arranged on opposite sides of the multi-ring gap air guiding section ( 12) a cooling water inlet (13) and a cooling water outlet (15), the suction nozzle (12) is connected to the air inlet of the high temperature induced draft fan (17); and the opposite sides of the water-cooled bottom plate (2) are provided with a water inlet ( 14) and the water outlet (16).
The vertical moving bed wood continuous carbonization and gasification apparatus according to claim 1, characterized in that the multi-ring gap gas guide section (3) and the water-cooled bottom plate (2) are double-layered shell water-cooled structures.