EP2784145A1

EP2784145A1 - Gasification reactor

Info

Publication number: EP2784145A1
Application number: EP12851812.3A
Authority: EP
Inventors: Larisa Jakovlevna SILANTYEVA
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-11-21
Filing date: 2012-11-16
Publication date: 2014-10-01
Also published as: RU2482164C1; WO2013077772A1

Abstract

The gasification reactor relates to the field of power engineering, more specifically to methods and devices for producing energy carriers in the form of hot water, steam and hot synthesis gas, producing electrical energy, heat and cold, and synthesizing liquid hydrocarbons. The technical result is that of increasing the calorific value of the synthesis gas produced without increasing the size of the apparatus, which is achieved by additionally equipping the reactor with: a lower agitating system having an upper vaned agitator situated in a heated truncated cone that is hermetically secured inside a housing; heat removing water rods, situated in a gas duct; an unsaturated hydrocarbon synthesis zone, situated below the housing of the heated truncated cone; and a methane synthesis zone, situated at the inlet to the gas duct of a water boiler; and also by virtue of positioning the nozzle of a burner inside the hermetic cavity between the walls of the heated cone and the housing thereof, as well as covering the gasification reactor on the outside with a heat-insulating material, and lining the inside surface of the primary gasification zone with heat-protective materials.

Description

Gasification reactor belongs to the field of power engineering, namely to methods and devices for the production of energy in the form of hot water, steam and fuel synthesis gas to produce electric power, heat, cold, synthesis of liquid hydrocarbons.
A known "Gas generator" design under the patent RU no. 2303050 dated 29.06.2006 , published on 20.07.2007, IPC C10J3/20, F23B99/00, includes a combustion chamber with a zone for drying and pyrogenic decomposition, zones of tar combustion, producer gas regeneration and purification, gas ducts of water boiler, steam generation chamber, air supply and heating chamber, wherein the gas generator is further provided with an exhausting separator, gas cooler stabilizer, and a chamber for producer gas heating, which are connected consecutively between the producer gas extraction zone and the combustion chamber, steam generation chamber is connected to the outlet of producer gas purification zone, with the inlet of regeneration zone and through the air heating chamber to the combustion chamber.
But this device does not provide gas calorific value higher than 1560 kcal.
The closest engineering solution is a gasification reactor of the patent RU no. 2360949 "Method of synthesis gas production and gasification reactor for its implementation" dated 04.08.2008, published: 10.07.2009, IPC C10J3/32, C10J3/40, C10J3/68.
Gasification reactor contains a boiler with two casings, inner and outer, concentrically arranged one inside the other made in the form of annular heat exchange jackets with gas duct between them, with a paddle agitator for raw materials and truncated cone, primary gasification and gas regeneration zone, burner, fire grate, injection lances for supplying steam to the regeneration zone, lid and reverse drive installed on it and connected to a suction tube with pipe spreader, with a paddle agitator for raw material installed under it and injection lances mounted on the free end of the pipe for supplying water steam from the water steam accumulation zone to the zone of primary gasification of raw materials.
But this design provides two-stage gas production with calorific value not exceeding 1560 kcal, because reducing caloric gas contributes to combustion of surplus synthesis gas in the combustion zone of primary gasification, since the synthesis gas already has plenty of nitrogen, and its combustion in this area causes an increase in the amount of nitrogen, at first in the primary gasification zone and then in the synthetic gas at the output. Moreover, burning of synthesis gas in the primary zone supports combustion temperature of 1500°C in order to increase the temperature in the regeneration zone to the maximum possible synthesis temperature, and at the same time, this temperature contributes to formation of NOx in the synthesized gas, and when using the produced gas in gas reciprocating power plants or burners of heating systems, where the burning temperature exceeds 1500°C, additional NOx is produced, resulting in pollution of the environment.
The purpose of the proposed solution is to improve the calorific value of synthetic gas produced, without increasing the dimensions of the installation.
The problem is solved by addition of a gasification reactor containing a boiler with two casings, inner and outer, concentrically arranged one inside the other made in the form of annular heat exchange jackets with gas duct between them, with a paddle agitator for raw materials and truncated cone, primary gasification and gas regeneration zone, and a burner; beyond that the reactor is additionally provided with: bottom agitating and ash disposal system with a top paddle agitator located in the heated truncated cone, fastened in the housing and hermetically sealed; heat-sinking water terminals located in the duct; zone for synthesis of unsaturated hydrocarbons located under the housing of the truncated cone, and a zone for synthesis of methane, located at the inlet of the gas duct to the water boiler; burner nozzle is installed in a sealed enclosure between the wall of the cone and its housing; the reactor is additionally provided with an air intake pipe with gas meter and controlled valve with electric actuator.
Provision of the gasification reactor with an additional lower-agitating system and upper blade agitator installed in a heated truncated cone, fastened in the housing, location of the burner nozzle in an enclosure between the wall of the cone and its housing provides for additional uniform heating of reagent in the cone, increasing efficiency of combustible gas production.
Installation of heat-sinking water terminals inside the duct allows to efficiently use the inner space of the water boiler and increasing the area of heat removal, without increasing the dimensions of the gasification reactor.
Provision of the gasification reactor with an additional zone for synthesis of unsaturated hydrocarbons installed under the housing of the heated truncated cone, and a zone for methane synthesis, located at the entrance of the duct, as well as a water boiler allows to use combustible gas produced in the regeneration zone and composed mostly of CO, CO2 and H2 to synthesize unsaturated hydrocarbons and methane, increasing the calorific value of synthesis gas to 1.5 ÷ 2.5 times.
Gasification reactor is depicted in the flow chart, where the following parts are numbered: fuel supply valve (1), upper cover of the reactor (2), upper level sensors (3), bottom level sensors (4), upper agitating system (5), gear-motor drive (6), injection lances (7), fuel chamber (8), zone of primary gasification (9), regeneration zone (10), heated truncated cone (11), burner nozzle (12), lower agitating and ash removal system (13), upper paddle agitator (14), grate (15), zone for synthesis of unsaturated hydrocarbons (16), zone for methane synthesis (17), paddles for ash residue removal (18), gear-motor drive (19), ash collector (20), ash removal device (21), steam boiler (22), water boiler (23), heat-sinking water terminals (24), steam chamber (25), air heating and air-steam mixing chamber (26), steam injection lances (27), air intake pipe (28), gas meter (29), valve with electric actuator (30), hot water level sensors (31), body of the cone (32), insulation material Korund (33), flow of synthesis gas (34) to the consumer, gas duct (35), flow of hot water (36) to the consumer, hollow tube (37) of the upper agitating system.
Gasification reactor is designed as follows.
The reactor contains water boiler (23) having two casings, inner and outer, concentrically arranged one inside the other made in the form of annular heat exchange jackets with gas duct (35) between them, with a paddle agitator for raw materials (5) and truncated cone (11), primary gasification (9) and gas regeneration zones (10), and a burner (12).
Gasification reactor is equipped with a top cover (2) with the fuel supply valve (1) installed in it and gear-motor drive (6) of the upper agitating system (5) located under the top cover (2) of the fuel chamber (8).
On the top cover, there are two redundant top fuel level sensors (3) of different lengths and two redundant bottom fuel level sensors (4), also of different lengths.
In the gasification reactor under the fuel chamber (8) there are zones of combustion and primary gasification (9), regeneration zone (10) inside the cone heated by flue gases (11) coming from the burner nozzle (12).
Injection lances (7) are located along the perimeter of the zone of primary gasification (9) and on the hollow tube (37) of the upper agitating system (5).
The reactor is equipped with bottom agitating and ash removal system (13), containing upper paddle agitator (14) in a truncated cone (11) fastened in its housing and hermetically sealed (32), under which there is a grate (15) with gear-motor drive (19) and paddles for removal of ash residue (18), ash collector (20), ash removal device (21).
Zone for synthesis of unsaturated hydrocarbons (16) connects to the beginning of the gas duct (35) to the zone for methane synthesis (17), and further to the consumer in the form of synthesis gas (34).
In a sealed enclosure formed between the walls of the heated cone (11) and its housing (32), the nozzle of the burner (12) is installed for heating of the cone (11) by burning gas-air mixture (11).
Water boiler (23) with two casings, inner and outer, concentrically arranged one inside the other made in the form of annular heat exchange jackets with gas duct (35) between them, is equipped with: air intake pipe (28) with gas meter (29) and automatically controlled valve (30) with electric actuator; steam supply chamber (25), chamber for air heating and its mixing with steam (26), providing stream injection through steam lances (7) to the zone of primary gasification (9); steam injection lances (27) to the zone for synthesis of unsaturated hydrocarbons (16) and zone for synthesis of methane (31).
Water boiler (23) has extra heat-sinking water terminals (24) installed in the gas duct (35), and hot water level sensors (31).
For the purpose of thermal insulation of external surfaces, the gasification reactor is covered by insulating material Korund (33) in an one anticorrosion insulation layer, a second traditional insulating layer, where each 1 mm of the layer thickness substitutes for 50 mm of a traditional thermal insulation material. The inner surface of the zone of primary gasification is lined with thermal protection materials, providing heat resistance up to 1800°C.
Gasification reactor operates as follows.
Fuel for gasification is supplied using valve (1) into the fuel chamber and fills it up until the top fuel level sensor would trigger (3).
Gear-motor drive (6) operates by the given algorithm is powering the upper agitating system (6), which moves fuel with its paddles from the valve (1) of the top cover (2) through the fuel combustion chamber (8), with the speed matching the fuel burning speed.
When the fuel level drops to the bottom fuel level sensor (4), it would trigger, initiating filling in the fuel chamber, until the top-level fuel sensor (3) will trigger. The fuel passes through the drying and preheating zones to the zone of primary gasification (9), where a water-steam mixture is supplied through injection lances (7).
In turn, the air required for the process of gasification is supplied through the air intake pipe (28) and hollow tube (37) of the upper agitating system. The amount of air is regulated by the gas meter (29), controlling the automatic valve with electric actuator (30).
Through the air intake pipe (28), air enters the air heating chamber (26) and is mixed with steam from the steam chamber (25). In turn, the steam produced in the steam boiler (22) through steam injection lances (27) is supplied to steam chamber (25). Steam in the steam boiler (22) is formed from hot water generated in the water boiler (23) and regulated by hot water level sensor (31).
Fuel is supplied into the zone of primary gasification (9), or otherwise the zone of primary combustion, where the steam-air mixture is used as oxidizing agent supplied from injection lances (7), and due to lack of oxygen, i.e. underoxidation of carbon fuel, an auto-thermal oxidation reaction between hydrogen, carbon, and sulfur proceeds at a temperature of not more than 1450°C allowing to reduce formation of nitrogen oxides, this chemical reaction is as follows:

C + 02 = CO2 +N2 + C↓; H2 +0.5 02 = H2O +N2; S + 02 = SO2 +N2.
Due to the fact that the reaction takes place with lack of oxygen, not oxidized carbon resides as a carbon fuel in the regeneration zone (10) inside the heated cone (11).
Regeneration zone (10) is located inside the heated cone (11) in order to provide additional heating of carbon residing from the fuel, heated by flue gases formed during the combustion of gas-air mixture obtained from surplus produced from excess of synthesis gas and combusted in the burner (12), installed in the enclosure between the wall of the housing (32) and the wall of the heated cone (11).
Lower agitating and ash handling system (13), with gear-motor drive (19) and upper paddle agitator (14) agitates fuel carbon residing in the heated cone (11) in the regeneration zone (10), moving it to the heated walls of the cone (11) and at the same time contributing to removal of the produced ash through the grate (15) falling to the bottom of the steam boiler (20), where the paddles (18) remove it to the ash collector (20) and the ash removal device (21).
Non-combustible gases produced in the primary gasification zone (9) are exhausted away and drafted through non-oxidized layer of carbon fuels in the regeneration zone (10), where they are recovered to the condition of combustible gases, CO, H2, trace amounts of CH4. In the regeneration zone (10) reaction takes place with heat absorption, causing the gas abruptly cooled to a temperature of 350 ÷ 500°C, instantly rushing past temperature of recovery of toxins.
Further, the gases leaving the regeneration zone (10) are supplied to the zone of synthesis of unsaturated hydrocarbons (16), characterized by technological parameters, such as temperature of the gas at this section, gas speed, additional steam blast pressure where gas is abruptly losing speed decreasing to speed of colloidal movement of particles smaller than 50 micron as it gets in the zone of expansion. With the loss of speed the temperature of the gas is also falling, reaching a temperature of synthesis of unsaturated hydrocarbons. Lack of hydrogen required for the synthesis is supplied through steam lances (27) from the steam boiler (22) in the form of steam.
From there the gas passes through the zone of methane synthesis (17), where its temperature reaches the temperature of methane and water steam formed in zone of synthesis of unsaturated hydrocarbons (16), in turn, contributing to supply of hydrogen for the reaction, while the gas cleared from mechanical impurities.
Heat released in the methane synthesis reaction is extracted to the steam boiler (22), in which a part of the water heated to 90° from the water boiler (23) is supplied.
Synthetic fuel gas (34) (hereafter "synthesis gas"), formed in a four-stage chemical reaction consists of a mixture of gases, such as CH4, CnHm, with small amounts of CO, CO2 and N2, where content of N2 does not exceed 41%, and the main component is methane; the synthesis gas has a calorific value of 2000 to 4000 kcal/Nm³.
The resulting synthesis gas (34) is supplied out through the duct (35), giving the heat to the annular heat exchange jackets (23) and heat-sinking water terminals (24) to dramatically increase the surface area of heat transfer and, due to being inside a duct (35), reduce the dimensions of the gasification reactor. In the gas duct (35) the gas is cooled to a temperature at which condensation of tar and later served for purification of condensed tar water.
Hot water obtained from annular heat exchange jackets of the water boiler (23) and heat-sinking water terminals (24) is distributed as follows: a part is supplied into the steam boiler, where is additionally heated to 114.7°C, and the most part is supplied to the consumer.
The technical effect is to improve the calorific value of synthetic gas produced, without increasing the dimensions of the installation but by equipping the reactor with the following additions: bottom agitating system upper blade agitator installed in a truncated cone, fastened in the housing and hermetically sealed; heat-sinking water terminals located in the duct; zone for synthesis of unsaturated hydrocarbons located under the body of heated truncated cone and the zone for methane synthesis, located at the inlet of the gas duct of the water boiler, and installation of the burner nozzle in the sealed enclosure between the walls of a heated cone and its housing;

Claims

The gasification reactor contains a water boiler with top cover with two casings concentrically arranged one inside the other made in the form of annular heat exchange jackets with gas duct between them, with the paddle agitator for raw materials and heated truncated cone, zones of primary gasification and regeneration, and a gas burner, characterized that the reactor is additionally provided with: bottom agitating system upper blade agitator installed in a heated truncated cone, fastened in the housing and hermetically sealed; heat-sinking water terminals located in the duct; a zone of synthesis of unsaturated hydrocarbons located under the housing of heated truncated cone, and a zone of methane synthesis, located at the inlet to the water boiler; the burner nozzle is installed in a sealed enclosure between the walls of heated cone and its housing; the outside of gasification reactor is covered with insulating material, the inner surface of the primary zone of gasification is lined with thermal protection materials.
The gasification reactor is similar to p.l but differs in that it is additionally provided with an air intake pipe with gas meter and controlled valve with electric actuator.