RU2338770C1 - Treatment method of wood biomass in form of combustive chips with receiving of bio-oil and wood coal and drying-retort module for treatment of wood biomass in form of combustive chips with receiving of bio-oil and wood coal - Google Patents

Abstract

FIELD: woodworking.

SUBSTANCE: declared group of inventions concerns method of wood biomass treatment in the form of combustive chips with receiving of bio-oils and wood coal, including drying, pyrolysis of wood biomass, wood coal tempering, selection of bio-oils from gas-vapor pyrolysis and coal in a one module, withdrawal of forming gas-vapor mixture of pyrolysis volatile products, at that formed pyrolysis gas-vapor with minimal temperature is withdrawaled from the area of active thermal decomposition with selection of bio-oils and directed to combustion chamber simultaneously to fed air, which is necessary for burning of deresined gas-vapor, at that fuel gases, formed during burning of deresined gas-vapor, at first dispose its heat for wood coal tempering, process of raw materials pyrolysis and then is directed for blending and forming of raw drying heat carrier, and also to the drying- retort module for wood biomass treatment in the form of combustive chips with receiving of bio-oils and wood coal, containing vertically installed body, divided by overclampings for drying chamber, chamber of wood biomass pyrolysis, mounted in top and bottom parts of facility body for charging of raw materials and discharge of coal, combustion chamber, unit of bio-oils selection and the first gaseous circuit in the form of gas flue with gas blower for feeding of gas-vapours pyrolysis chamber of wood biomass and coal tempering into combustion chamber, located in pyrolysis area of wood biomass and coal tempering, at that module is additionally outfitted by blending chamber for forming of drying heat carrier, connected through the gaseous circuit to combustion chamber, and the second gaseous circuit in the form of gas flue with regulating cap for feeding of smoke fumes from combustion chamber to the bottom part of drying area of wood biomass.

EFFECT: usage of mentioned above inventions provides increasing of utilisation level of wood refuses with receiving of bio-fuel with high energy density, increasing of method dedicated throughput and module and providing of ecology at the expense of toxic discharges into environmental absence.

4 cl, 5 dwg

Description

The invention relates to the forest industry and can be used in the processing of logging waste, sawmilling, woodworking and thinning for the production of biomasses and charcoal from wood biomass in the form of wood chips.

A known method of producing charcoal (RU 2088632, 03.16.1994, СВВ 53/02). The method includes drying, thermal decomposition at 200-400 ° C, pyrolysis of the raw material by supplying hot flue gases to the raw material, removing excess steam and gas mixture formed, cooling the charcoal and differs in that the gas-vapor mixture and hot flue gases are recycled during drying and thermal decomposition moreover, all stages of the process are carried out in one chamber, and coal is cooled by passing atmospheric air between the casing and the walls of the chamber.

A known method of thermal processing of wood (RU 2083633, 11.24.1995, СВВ 53/02). The method includes preliminary drying of wood and subsequent heat treatment in the presence of a gaseous coolant in a continuous process with successive passage of drying zones, pyrolysis with the formation of charcoal, its calcination and cooling with countercurrent supply of a cooling agent, which uses flue gases from complete combustion of fuel containing oxygen in them is 1.5-7.0%, while these gases after passing through the cooling zone are used as a coolant in the calcination zones, pi Rolise and drying.

The methods described above are low productivity, require additional fuel and do not allow the processing of wood with a moisture content above 25%.

A known installation for pyrolysis of wood is a vertical continuously operating retort (Vyrodov V.A., Kislitsyn A.N. Technology of wood chemical production. M: Forest industry, 1987, p.216-218). It is a steel cylindrical chamber with internal heating, mounted vertically and containing distribution cones for entering the coolant and the selection of steam and gas, a device for loading wood and coal, a condensation system for processing steam and gas. The height chamber is conditionally divided into three zones: wood drying, pyrolysis and calcining of coal, coal cooling. Pyrolysis steam gas is processed in a condensation system to remove liquid pyrolysis products. The remaining non-condensable gases diluted with the coolant (flue gas) are fed in a mixture with additional fuel for combustion and formation of the coolant for pyrolysis in a special furnace device. The disadvantages of the installation are: the need to process combined-cycle gases, which complicates its operation, the need for additional fuel, the lack of the possibility of processing wood with a humidity above 25%.

A well-known installation for pyrolysis of wood is a retort of the company Lambibit (Vyrodov V.A., Kislitsyn A.N. Technology of chemical production. M: Forest industry, 1987, p.218-220). It is a cylindrical chamber mounted vertically, with the transition in the lower part into a cone. Conditionally, the height retort can be divided into 3 parts: the upper one, intended for drying wood, the middle (extended), where pyrolysis and calcination of coal takes place, the lower one - the coal cooling zone. In the interval between the upper and middle zones, there is a furnace device, where, using gas blowers, hot pyrolysis steam gas, taken from the bottom of the middle part of the retort (pyrolysis zone), as well as combustion gas are supplied through special fittings. In the upper part, the installation is equipped with a device for loading wood, in the lower - a device for unloading coal. Thus, the retort “Lambibit” eliminates the need for a condensation system to trap liquid products. The heat from burning raw steam and gas is sufficient to ensure the thermal regime of drying and pyrolysis of wood with a moisture content of up to 35%, in which case additional fuel is not required.

The disadvantage of the retort "Lambit" is the location of the combustion device in the gap between the pyrolysis zone and the drying zone of wood. Partially burnt gas-vapor from the combustion device is fed to a retort on a wood layer heated only to 100 ° C, which excludes continued combustion and leads to the extinction of the torch. The temperature in the pyrolysis zone of the retort therefore does not exceed 500 ° C, which reduces the productivity of the installation, does not allow to obtain high-quality coal due to insufficient calcination, and excludes the possibility of processing wood with a humidity above 35%. The coolant leaving the drying zone contains unburned resin and other hardly combustible ingredients, which leads to irretrievable heat losses and the emission to the atmosphere of the working area. The distribution of gas flows in the retort "Lambibit" is not regulated.

A known method for the production of charcoal and installation for the production of charcoal (RU 2166527, 02.01.2000, CB 53/02). The method includes preliminary drying of the raw material and subsequent heat treatment in the presence of a gaseous coolant in a continuous process with successive passage of the drying, pyrolysis zones with the formation of charcoal and its calcination. The use of a gas coolant in the pyrolysis zone dramatically reduces the concentration of wood-tar products in combined cycle thermal decomposition of raw materials, increases their temperature and complicates the condensation system for the separation of bio-oils. The known decision was made as a prototype.

The tasks to which the invention is directed are to increase the level of waste wood utilization to produce biofuels with high energy density, increase the specific productivity of the method and module and ensure the environment due to the absence of toxic emissions into the environment.

The tasks are solved as follows. A method of processing wood biomass in the form of wood chips to produce biomass and charcoal includes drying, pyrolysis of wood biomass, charcoal calcination, selection of biomass from pyrolysis steam and coal in one module, removal of the resulting vapor-gas mixture of volatile pyrolysis products, with the resulting pyrolysis steam and gas from at a minimum temperature, they are diverted from the zone of active thermal decomposition with the selection of bio-oils and sent to the combustion chamber at the same time as the incoming air necessary for burning the tarless steam call, with the flue gases formed during combustion degummed steam and gas initially give off their heat to the calcination charcoal, raw pyrolysis process and then sent to the mixing and forming raw coolant drying.

The drying-retort module for processing wood biomass in the form of wood chips to produce bio-oils and charcoal contains a vertically mounted case, separated by clamps on the drying chamber, a tree biomass pyrolysis chamber, mounted in the upper and lower parts of the casing of the device for loading raw materials and unloading coal, furnace a chamber, a biomassel sampling unit, and a first gas circuit in the form of a gas duct with a gas blower for supplying gas and vapor from the biomass pyrolysis chamber of a tree and calcining coal into a combustion chamber located in the pyrolysis zone for wood biomass and coal calcination, the module is additionally equipped with a mixing chamber for forming a drying coolant connected through a gas circuit to the combustion chamber, and a second gas circuit in the form of a gas duct with a control flap for supplying flue gases from the combustion chamber to the lower part of the biomass drying zone tree.

In addition, the module is additionally equipped with a third gas circuit in the form of a gas duct with a control damper and a gas blower for recirculating flue gases from the upper part of the drying zone to its lower part for a reverse-counter-current-transverse raw material preparation process for the production of bio-oils and coal from wood biomass .

In addition, in the module, the unloading device for unloading coal is made in the form of a screw drive with external cooling and a sealed device for unloading the resulting coal.

The invention is illustrated by drawings. Figure 1 (a and b) shows a schematic diagram of the module, figure 2 is a section of the module along section A-A, figure 3 is a section of the module along section BB, figure 4 is a section of the module along section B -AT.

The drying-retort module for processing wood biomass in the form of wood chips to produce bio-oils and charcoal (hereinafter referred to as the module) includes: a chimney 1, a feed bin 2, a feed device 3, gas ducts 4, a cooling zone 5, a gas blower 6, gas channels 7 , blinds 8, drying chamber 9, centrifugal resin separator 10, bio-oil drip catcher 11, chimney 12, coal pyrolysis and calcining chamber 13, combustion chamber 14, blower 15, coal unloading device 16, pinch clamps 17, mixing chamber 18, steam and gas extraction pipe 19, service sites 20, regulating flaps 21, burners 22.

The module consists of vertically arranged chambers that conditionally divide it into a zone of reverse-countercurrent drying of raw materials — chamber 9, a zone of pyrolysis of wood biomass and calcination of coal — chamber 13, a biomassel selection unit — a tar separator 10, and a droplet collector 11. The module is equipped with a feed device 3 and coal unloading device 16. The chambers are separated by pincers 17, which are a truncated cone. In the lower part of the installation in the zone of pyrolysis of wood biomass and calcining coal, a combustion chamber 14 is installed, equipped with chimneys 12 with control flaps 21 for supplying flue gases to the drying chamber 9.

In the upper part, the module is equipped with an additional circulation circuit in the form of gas ducts 4 with control flaps 21 and gas blowers 6 for recycling part of the spent drying agent, as well as a chimney 1 to discharge its excess into the atmosphere.

The module works as follows. From the raw material bin 2, through the loading device 3, which ensures the tightness of the installation during the loading period, the raw material enters the module, where the drying chamber 9, the pyrolysis and calcining chamber of coal 13 pass sequentially. The calcined coal is partially cooled in the cooling zone 5 and through the unloading device 16 derived from the module.

The unloading device 16 is made in the form of a screw drive with external cooling and a sealed device for unloading coal.

During operation of the module, the resulting pyrolysis vapor gas is removed from the active decomposition zone of the raw material from the clamps 17 through the nozzle 19 and centrifugal resin separators 10, the bio-oil droplet collectors 11 and the burners 22 are fed into the combustion chamber 14. There, air blowers are also injected with blowers 15 to burn the resin-free steam and gas . The combustion gases generated during combustion first heat the walls of the pyrolysis chamber 13, then they are sent to the mixing chamber 18 to form the drying coolant and through the shutters 8 the coolant in the transverse direction contacts the raw material. Biomasses are selected from the drop catchers 11.

Inside the module, three circuits of combined-cycle flows are used, the mass flow of which is regulated by specified operating factors for pressure and temperature: the first according to the scheme "pyrolysis chamber - centrifugal resin separator - droplet collector - furnace", the second according to the scheme "flue gases - recirculation steam - waste drying agent ”, 3rd according to the scheme“ drying agent - drying chamber - drying agent reverse - drying agent ”. This allows you to adjust the volume of gas flows by the set pressure mode in the module zones and thereby maintain the required temperature regime.

Separation of bio-oils from concentrated vapor-gases of exopyrolysis of the module with external additional heating is necessary in order to reduce heat production, i.e. the temperature of the flue gases should be no higher than 900-950 ° C, since the combustion temperature of non-tarred combined-cycle gases can reach 1300-1450 ° C, and this would greatly complicate the operation of the module and would require the use of expensive materials in the furnace unit.

After warming up the module and entering the operating mode, the amount of heat obtained from burning tarless combined-cycle gases is sufficient to provide a closed heat balance for drying and exopyrolysis of raw materials with a wood chip moisture of even freshly cut wood up to 55 rel.%.

The location of the combustion chamber in the lower part of the module and the sequential promotion of flue gases at first to heat the walls of the pyrolysis chamber with the subsequent formation of a heat transfer fluid reduces the gas flows of the module and the cost of electricity for their circulation. The resulting flue gases from the combustion chamber 14 enter a zone with a high temperature - a pyrolysis and calcination chamber of coal 13, where the combined combustion of gas and vapor occurs.

The high temperature of the flue gases supplied to the drying and pyrolysis sharply (4-6 times) accelerates the processing of wood biomass in the form of wood chips and increases the specific productivity of the module, which allows us to develop a portable unit up to 1 t / h in a.s. raw materials, and also contributes to the production of highly calcined coal with improved consumer properties. Since the tarred pyrolysis combined cycle gases completely burn out, their emission into the atmosphere is excluded, which does not violate the ecology of the area. The exclusion of a typical coal cooling zone in the module case drastically reduces its dimensions and simplifies the operation of the module.

The proposed inventions will find application in the production of bio-oils with an energy consumption of up to 29 MJ / kg and charcoal from wood waste in the form of wood chips.

Claims (4)

1. A method of processing wood biomass in the form of wood chips to produce bio-oils and charcoal, including drying, pyrolysis of wood biomass, calcining charcoal, selecting bio-oils from pyrolysis steam and coal in one module, discharging the resulting vapor-gas mixture of volatile pyrolysis products, while forming pyrolysis gas-vapor with a minimum temperature is removed from the zone of active thermal decomposition with the selection of bio-oils and sent to the combustion chamber simultaneously with the incoming air necessary for burning the tarless rogazov, the flue gases formed during combustion degummed steam and gas initially give off their heat to the calcination charcoal, raw pyrolysis process and then sent to the mixing and forming raw coolant drying. 2. A drying-retort module for processing wood biomass in the form of wood chips to produce bio-oils and charcoal, comprising a vertically mounted housing separated by clamps on a drying chamber, a wood biomass pyrolysis chamber mounted in the upper and lower parts of the device for loading raw materials and unloading coal, a combustion chamber, a biomassel sampling unit, and a first gas circuit in the form of a gas duct with a gas blower for supplying steam and gas from the pyrolysis chamber of wood biomass and calcining coal into a combustion chamber located in zone the biomass of wood biomass and calcination of coal, while the module is additionally equipped with a mixing chamber for forming a drying coolant connected through a gas circuit to the combustion chamber, and a second gas circuit in the form of a gas duct with a control valve for supplying flue gases from the combustion chamber to the lower part of the biomass drying zone tree. 3. The module according to claim 2, characterized in that it is additionally equipped with a third gas circuit in the form of a gas duct with a control damper and a gas blower for recirculating flue gases from the upper part of the drying zone to its lower part for a reverse-counter-flow-through process of preparing raw materials with the goal of producing biomass and coal from wood biomass. 4. The module according to claim 2 or 3, characterized in that the unloading device for unloading coal is made in the form of a screw drive with external cooling and a sealed device for unloading the resulting coal.

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