CN115803417A - Method for gasifying carbonaceous feedstock and device for carrying out said method - Google Patents

Abstract

A method and gas generator for gasification of carbon-containing raw materials, which belong to the field of gasification of carbon-containing raw materials, can be used in chemical industry, petrochemical, coking, electric power and other related industries, and are mainly used for processing carbon-containing raw materials to produce energy gas and process gas , to produce synthesis gas by partial oxidation of carbon-containing streams. In the process of gasification of carbonaceous feedstocks comprising partial oxidation of carbonaceous feedstocks in an oxidation chamber in a mixture of oxygen-containing gas and water vapour, unlike known methods, the partial oxidation is installed coaxially in vertical oxidation chambers In the partial oxidation channel, the water vapor supply for partial oxidation of carbonaceous raw materials is carried out at the inlet and outlet of the vertical oxidation channel in the combustion chamber. The gas generator includes a body, a combustion device, a vertical oxidation chamber, a collector for carbonaceous raw materials, water vapor and oxygen-containing gas, a gasification product discharge pipe, and a slag removal chamber. The difference is the further introduction of a partial oxidation channel, which is coaxially arranged in the vertical oxidation chamber and attached to the upper interior of the housing where the burner device is integrated. The declared method and device can make the hydrogen content in the industrial gas high, so that the refinery can efficiently use the heavy oil residue and obtain high-quality engine fuel. The declared device can become the main basic device of the coal chemical industry. Such devices are equally important for the hydroprocessing of coal and for the production of synthesis gas from coal.

Description

Carbonaceous raw material gasification method and implementation device thereof

technical field

The invention relates to chemical industry, petrochemical, coking, electric power and other related industries, and can be preferentially used in the processing of carbon-containing raw materials to generate energy gas and process gas, especially the gasification of carbon-containing raw materials and the partial oxidation of carbon-containing streams to produce synthesis gas.

Background technique

The production of synthesis gas by partial oxidation is now well known in the art employed. Typically, streams containing carbon (hydrocarbons), such as coal, lignite, peat, wood, coke, soot or other forms of gaseous, liquid or solid fuels or mixtures thereof, are partially combusted in the gasification reactor, i.e. in the Partial combustion in the gasification reactor. Partial oxidation is carried out using an oxygen-containing gas, such as nearly pure oxygen or not necessarily oxygen-enriched air, etc., resulting in a product stream containing syngas (ie CO and _H2 ) and _CO2 .

Coal gasification technology is mainly divided into three types: fixed bed gasifier, such as the gasifier produced by Germany Lurgi AG. Frankfurt am Main) [1, pp. 161-167] Fluidized bed or fluidized bed gas generator with "U-Gas", "Winkler" (USA, Chicago Institute of Gas Technology) [1, pp. 167 - 173 pages] and "Shell" (joint production of Shell and UHDE, Buggenum installation in the Netherlands) [1, pp. 189-191] and "Texaco" (USA, Texaco GP, Cool Water and Polk installations) [1 , pp. 176-180] for parallel flow gas generators.

Fixed-bed gas generators have disadvantages such as low processing capacity of a single device, expensive synthesis gas and water treatment systems, and operational safety issues.

Fluidized bed gasifiers have low efficiency due to low carbon conversion rate, difficulty in discharging dry bottom ash, and high fly ash entrainment.

The above-mentioned disadvantages do not exist when the parallel flow gasification process is adopted. In a parallel flow gasification unit, almost all types of carbonaceous feedstocks can be partially oxidized to obtain industrial gases with defined properties. In addition, this gas generator has a small volume and can provide a higher gasification raw material yield.

Disadvantages of the parallel flow gasification process include:

1. The gasification of solid and liquid fuels of any type in parallel flow can only be effectively carried out with a fine atomization, typically less than 75 microns in particle size. In this case, a large fraction of feedstock particles can significantly reduce the efficiency of the process and the quality of the resulting gas.

2. In the gasification process of solid and liquid fuels, in order to obtain industrial gases (water gas, syngas and their mixtures) with the highest hydrogen yield, it is necessary to use water vapor or a mixture of steam and oxygen to oxidize the raw material, which will maintain the necessary Optimum process temperatures around 900-1100°C cause problems for ignition of the mixture [2, pp. 26-27, 31].

A schematic diagram of a gas generator operating with the "Koppers-Totzek" method is known [1, pp. 174-176], in which the gasification takes place at atmospheric pressure. According to the Koppers-Totzek process, specially prepared ground and dried fuel enters the fuel tank, from where it is fed by a metering screw into a mixing nozzle and then into an oval reaction chamber consisting of two to four combustion chambers facing each other. Mixing nozzle composition. In the combustion nozzle, the pulverized fuel is mixed with oxygen and water vapor, causing the water vapor to form a steam jacket outside the pulverized oxygen torch, thus protecting the refractory lining of the reaction chamber from slagging, erosion and high temperature inside the flame. The combustion temperature inside the torch is 1500-1700°C, and its temperature level is maintained according to the melting temperature of the ash. Ash in liquid form is removed from the bottom of the reaction chamber into a special device, where it is cooled and pelletized. Disadvantages of this gasifier include:

1. Increased oxygen consumption compared to other known steam-oxygen gas generators;

2. Reduced hydrogen production rate due to high temperature;

3. Low safety, since even small deviations from the nominal regime can lead to explosive concentrations of gaseous products in the reaction chamber.

4. Due to the high process temperature, the construction of the gas generator has higher requirements for structural materials.

The 'Destec' coal gasification process is also known and aims to expand the fuel base by switching from natural gas to coal, originally developed by the Dow Chemical Company [1, pp. 180-183]. For coal gasification, a two-stage flow type liquid slagging coal gasifier has been developed. Fuel is fed into the reactor in the form of coal-water slurry (coal/water=60/40%) under high pressure generated by pumps. The gasification agent uses high-purity oxygen (95%) produced by a special device. The working pressure of the gasifier is 2.75MPa and the temperature is 1371°С. However, the process temperature depends on the type of fuel used and increases when more refractory ash is present due to liquid slagging. The coal-water slurry is transported to the bottom of the gas generator and mixed with oxygen at the same time. Coal is partially oxidized to provide heat for endothermic reactions in the gasification zone. The slag produced in the first stage is discharged into a water tank and then used in construction. The raw gas of the power generation unit enters the upper lining part of the reactor, and the coal water slurry is also introduced in this part. In this part, the new fuel reacts with the generator gas obtained in the first stage of the process. In the second stage, the combustion temperature of the generator gas increases, and the endothermic reaction cools it down to around 1038°C.

Disadvantages of this gas generator include:

1. There are technical problems in the use of coal water slurry;

2. High temperature and high pressure lead to a decrease in hydrogen yield;

3. The yield of carbon dioxide is improved, compared with other DC gasifiers (that is, the heat generated is lower than that of similar gases);

4. Due to the high process temperature, the construction of the gas generator has higher requirements for structural materials.

5. Use high-purity oxygen as gasification agent.

Tyssenkrupp AG's PRENFLO (Pressurised Entrained-Flow) steam generation process [1, pp. 183-186] is also known as "PRENFLO" (PRENFLO), which is used in any type of solid fuel (coal, petroleum coke, biomass ) on pressurized operation. The process is based on the "Koppers-Totzek" technique. In the gas generator, the prepared fuel is gasified at a pressure of about 4MPa.

At this time, the gasification temperature is higher than the ash melting point (1400-1600°C), and liquid slag discharge can be carried out. The advantage of this process is that the raw material fuel for gasification is supplied dry. Fine coal (80% less than 0.1 mm in volume) is supplied together with oxygen and steam through four burners located at the same level as the bottom of the gas generator. Disadvantages of this gas generator include:

1. Due to the high temperature and pressure, the hydrogen yield is reduced (in the chemical industry, it is only used in places where the hydrogen content in the process gas is not high);

2. The high temperature and pressure lead to higher requirements on the materials used in the construction of the gas generator, and the financial cost of manufacturing the gas generator is high.

Also known as carbon-containing raw material gasifier (Ru No. 2237079, МПКC10J3/20, this number was issued on September 27, 2004), it is a carbon-containing raw material gas generator, which can be used for processing in chemical, petrochemical, coke oven gas, electric power and other related industries Carbonaceous raw materials for the production of energy and process gases. The gasifier consists of a vertical gasification chamber, burners for delivery of carbon-containing feedstock and oxygen-containing gas, steam headers, nozzles for delivery of carbon-containing powdery feedstock, gasification product discharge tube (at the bottom of the gasification chamber), the slag removal chamber, and at the same time a special unit consisting of a burner placed in the center of the unit above the gasification chamber and nozzles around the burner located on the periphery of the unit above the gasification chamber , to create a steam curtain that protects the vaporizer lining from overheating. The gasification chamber is a cylindrical pipe terminated by a conical slagging chamber in which the gasification chamber is conditionally decomposed into an oxidized part and a reduced part. The process temperature in the oxidation zone is 1500-3000°C, and in the reduction zone, the temperature is reduced to 1000-1600°C by steam supply.

Disadvantages of this gas generator include:

1. Reduced hydrogen production rate due to high temperature;

2. When using a gasifier as a thermal energy source, the efficiency of the unit is reduced because the presence of free hydrogen and high levels of carbon monoxide indicate incomplete combustion.

3. The position of the exhaust pipe at the bottom of the gasification chamber determines that a large amount of slag and ash enter the flue and gas distribution system, which may cause rapid failure of the gasifier.

It is well known that the gasification method in the "Prenflo" PDQ gas generator of ThyssenKrupp AG is considered the closest approach [1, pp. 186-189], more advanced than its predecessor "Prenflo" PSG, later Or run according to the "Koppers-Totzek" process. The gas generator gasifies fine coal dust mixed with oxygen and water vapor in a vertical oxidation chamber at a temperature of 1400-1600 °C. The oxidation of coal actually takes place under adiabatic conditions, because the oxidation chamber is a channel coaxial with the outer wall of the gas generator, separated from the outer wall by an annular space washed by coal oxidation products, so that the temperature of the oxidation chamber is maintained at Between 1400-1600°C. Coal dust and a mixture of oxygen and water vapor are conveyed through 4 horizontal burners at the top of the oxidation chamber. The oxidation chamber enters the rapid water cooling chamber, and water is injected into the rapid water cooling chamber through the annular hole in the cooling chamber to cool the oxidation product to a temperature of 200-250°C.

The closest to the declared installation is the gas generator [1], which implements the prototype method, including the mains for supplying water vapor and oxygen to the burner, the mains for supplying the gas-coal mixture to the burner, the access to the rapid water cooling chamber The oxidation chamber, rapid water cooling chamber is a cylindrical tube placed coaxially inside the gas generator housing, ending with a conical slag removal chamber. An annular gap is set between the slag removal chamber and the central pipe of the fast cooling chamber, and the oxidized raw gas and water vapor leave the cooling chamber through the annular gap, and then rise along the wall gap between the cooling chamber pipe and the gas generator shell to leave the gas generator. The furnace enters the gasification product discharge pipe for further processing.

The sharp change of gas flow in the rapid cooling chamber makes the downward movement of the gas change to upward movement after passing through the gap between the cooling chamber pipe and the slag removal chamber, so that a large amount of slag and ash can be separated into the conical slag removal chamber. The slag removal chamber is connected with the slag removal system.

The slag from the gasifier can be used as a construction material.

Disadvantages of this gas generator include:

1. Reduced hydrogen yield due to high temperature and pressure (in the chemical industry, these gas generators are only used where the hydrogen content in the process gas is not required). The total amount of hydrogen does not exceed 22-32% (same as all once-through gas generators, based on Koppers-Totzek technology (Shell-copper-copper process), while for Lurgi stratified gas generators, the hydrogen content in the dry gas is 36-40 %, for Winkler fluidized bed gas generators [1, pp. 169-170], the hydrogen content is between 35-45% [4, p. 30].

2. The high temperature and pressure lead to higher requirements on the materials used in the construction of the gas generator, and the financial cost of manufacturing the gas generator is high.

3. Increased specific oxygen consumption per ton of gasified coal, all Koppers-Totzek (540-650 ^m3 ), and for stratified gas generators, Lurgi 220-300 ^m3 and for Winkler fluidized bed gas Generator - 350m ³ [4, pp. 30-33].

4. In order to ensure stable ignition and maintain stable combustion of the mixed gas, in addition to increasing oxygen consumption, the oxidation chamber also adopts a horizontal burner arrangement, which does not allow the process temperature to be lowered to 900-1100°C (the optimum temperature for syngas production ), because at such temperatures (900-1100°C) the ash content of the vast majority of coal is in solid phase, which means that ash may accumulate on the combustion chamber walls, leading to slagging and further failure of the gas generator.

5. The cooling of the gas to 200-250°C is too rapid to allow additional hydrogen to be generated through the reaction

CO+H ₂ O=CO ₂ +H ₂ +10300 kcal, (1)

Because already at 800°C water vapor decomposition is within an order of magnitude less than at 1000°C, with the same residence time and contact time of 1 second, the conversion of water vapor at 800°C will be only 0.5% of the conversion at 1000°C [2, p. 29]. This means that at lower temperatures, there is no reaction at all, as evidenced by the increase in the equilibrium constant (1) for this reaction at 500°C, which is 100 times greater than at 1000°C [3, p. 102].

Contents of the invention

The main task of the present invention is to provide an efficient process for the gasification in parallel flow of carbonaceous raw materials such as coal, lignite, peat, wood, coke, carbon black or other forms of gaseous, liquid or solid fuels, or mixtures thereof , using a method of partial oxidation of hydrocarbon feedstock in a mixture of oxygen-containing gas and water vapor and its implementation device, in order to obtain as high a hydrogen yield as possible during the gasification of carbon-containing feedstock.

The technical result of the claimed invention is to obtain a generator gas with increased hydrogen content. In this case, ignition stability is achieved and the necessary partial oxidation temperature is maintained.

The declared technical result is achieved by the partial oxidation of carbonaceous feedstock in an oxidation chamber in a mixture of oxygen-containing gas and water vapor in the known gasification process of carbonaceous feedstock, the partial oxidation being carried out at the same time The shaft installation is carried out in the partial oxidation channel in the oxidation chamber, and the water vapor supply for partial oxidation of carbonaceous feedstock is carried out at the inlet and outlet of the partial oxidation channel in the combustion chamber.

At a temperature of 900-1100°C, the partial oxidation is optimally carried out in the mixed flow of oxygen and water vapor in the partial oxidation channel of the oxidation chamber, provided by the change of the steam volume at the inlet of the partial oxidation channel.

It is feasible to control the outlet temperature of the partial oxidation channel in the oxidation chamber within the range of 800-1000°C, which is provided by the change of the steam volume at the outlet of the partial oxidation channel.

It is feasible to ignite the carbon-containing raw material and the gas-oxygen mixture and maintain its stable combustion by supplying combustion products to the inlet of the partial oxidation channel through a combustion device installed along the axis of the partial oxidation channel.

Preferably the residence time of the combustion products in the oxidation channels is greater than the combustion time of the largest feedstock particles.

The geometry of the partial oxidation channel should be optimally selected according to the following relationship:

L≥(4*G*T _b )/(π*ρ(t _O )*D ² ),

in

L - partial oxidation channel length;

D - the diameter of the partial oxidation channel;

G——A large number of oxidation products enter the partial oxidation channel;

_Tb - combustion temperature of the largest particle of carbonaceous raw material;

t _O - the calculated temperature of the oxidation product in the partial oxidation channel;

ρ(t _O )—the calculated density of oxidation products in the partial oxidation channel.

Coal, lignite, peat, wood, coke, soot and other solid fuels or gaseous fuels and liquid fuels or their mixtures can be used as carbonaceous raw materials.

The technical achievement also lies in the known gas generator for the gasification of carbonaceous feedstock, comprising a housing, a combustion device, a vertical oxidation chamber, collectors for carbonaceous feedstock, water vapor and oxygen-containing gas, gasification product discharge pipes . The slag removal chamber also includes a partial oxidation channel, the partial oxidation channel is coaxially arranged in the vertical oxidation chamber and fixed on the upper inner side of the casing, and the partial oxidation channel is integrated with a combustion device.

The upper part of the housing is preferably designed as a removable cover, in which the combustion device is integrated.

The gasification product discharge pipe may be installed at a side of the gas generator housing that is closer to the top of the gas generator.

The best design gasification furnace for gasification of carbonaceous raw materials. The furnace contains upper and lower steam main pipes, which adopt a hollow ring design and are connected by a downcomer whose axis is parallel to the axis of the shell. The upper main pipe is installed on the outside of the gas generator cover, and the downcomer is installed On the outside of the partial oxidation channels, a lower steam header is installed at the outlet of the oxidation channels and is provided with holes for discharging steam into the partial oxidation product stream.

The combustion device is preferably designed in the form of a diffusion burner provided with an annular channel arranged coaxially in the direction of the diffusion burner and designed to feed oxygen-containing gas, hydrocarbon feedstock and water vapor into the annular channel.

The inner wall of the oxidation chamber is reasonably designed as a coil. The upper end of the coil is connected to the upper steam main pipe through the hot steam distribution component, and the lower end is connected to the external water steam generator.

The inner wall of the oxidation chamber may be configured as a coaxial annular container allowing the supply of water vapor from the bottom of the oxidation chamber to the cover of the gas generator.

Partial oxidation channels can be done with external thermal insulation.

The so-called gasification method of carbonaceous raw materials such as coal, lignite, peat, wood, coke, soot or other forms of gaseous, liquid or solid hydrocarbon fuels or mixtures thereof and its implementing devices are unknown from the prior art The, therefore, alleged solution meets the patentability conditions for Novizn's invention.

An analysis of whether the declared solution meets the technical level of the "invention level" condition for the patentability of an invention is shown below.

In the proposed method for the gasification of carbonaceous feedstocks, such as coal, lignite, peat, wood, coke, soot or other forms of gas, a liquid or solid is propelled by partial oxidation in a mixture of oxygen-containing gas and water vapour. Partial oxidation of the reagents or their mixtures to maximize the production of hydrogen, unlike known devices, the oxidation process is actually divided into two stages: first under adiabatic conditions, at 900-1100 ° C Optimum temperature for adiabatic conditions for adiabatic conditions for adiabatic conditions , under adiabatic conditions, under adiabatic conditions, the partial oxidation is carried out under adiabatic conditions in a mixed flow of oxygen and water vapor, and then at the outlet of the partial oxidation channel, the gas produced is oxidized separately with water vapor, maintaining the temperature in this area In the optimum temperature range of 800-1000°C. In the proposed device, in order to realize the oxidation method described, all processes are carried out under conditions that prevent a sharp increase in the pressure of the reaction space, unlike similar devices. In addition, the stated method allows stable ignition and combustion in a two-phase flow obtained on the surface of particles and in the gas phase through the stable input of additional thermal energy from the combustion products of built-in combustion devices burning liquid or gaseous fuels. The combustion product of the combustion device enters the partial oxidation channel along the channel axis, and mixes with the carbon-containing raw material and the gas-oxygen mixture.

In this case, when the combustion device burns any fuel, it maintains the stability of the ignition and the maintenance of the necessary temperature in the oxidation channel through the thermal energy input from the upper part of the gas generator shell, regardless of whether there is carbon raw material entering the gas generator. The device is oxidized. For example, unlike the prototype and other known means, the oxygen in the air is stabilized by high oxygen consumption to burn partially oxidizable carbonaceous feedstock, in which high temperatures of 1400-1600 °C are generated at a pressure of 27 -40atm, so the hydrogen yield is reduced. Carrying out the process at optimum gasification conditions and temperatures allowed the use of low-cost materials in the design of the gas generator, while the burner in the prototype was mounted on the vertical axis of the gas generator (causing high temperatures when the combustion product streams collide) . Therefore, the declared invention group satisfies the condition of "invention level".

Description of drawings

The method and apparatus for gasifying carbonaceous feedstocks are illustrated in the accompanying drawings, wherein

Figure 1 shows the overall scheme of the gas generator for the gasification of carbonaceous raw materials;

Figure 2 presents a cross-sectional view of the gas generator;

Fig. 3 has introduced the schematic diagram of gasifier combustion device;

Figure 4 shows a schematic diagram of a coil gas generator for steam preheating and shell wall cooling;

Figure 5 shows a schematic diagram of a gas generator with a set of annular vessels for heating steam and cooling the walls of the gas generator.

Detailed ways

The claimed gas generator for the gasification of carbonaceous feedstock comprises a housing 1, an oxidation chamber 2, a housing cover 3 (Fig. 1), a combustion device 4 (Fig. 4), with a diffusion burner 7, oxygen and water Supply branch pipe 6 for steam and carbonaceous raw material mixture, pipe 8 for discharging generator gas, partial oxidation channel 9 with thermal insulation layer 10, main pipe 12 with steam delivery to space at the outlet of oxidation channel 9, And the downcomer 13 ( FIG. 2 ), which supplies steam from the upper steam main 14 to the steam main 12 . A slag removal chamber 11 is provided at the lower part of the shell.

FIG. 2 provides a sectional view A-A ( FIG. 1 ) of the gas generator, which shows the layout of the steam supply port 15 in the steam supply main pipe 12 . Figure 3 shows a schematic diagram of a combustion device 4 with a built-in diffusion burner 7, an air supply channel 16, a fuel supply channel 17 (such as oil or gaseous fuel), an ignition electrode 18, a mixing diffuser 19, an oxygen supply Channel 20 and steam supply channel 21. Fig. 4 provides the schematic diagram of the gas generator of Fig. 1, add the steam preheating of the gas generator shell 1 and the insulation cooling coil 22, introduce the steam into the coil 22, and introduce the steam distribution assembly 24 into the steam of the carbonaceous raw material 25 The mixing assembly and header 14 introduces the coal into the mixing assembly 26 . Fig. 5 provides the schematic diagram of the gas generator of Fig. 1, increases the annular steam preheating container 27 and the insulation cooling container 27 of gas generator shell 1, introduces steam into short pipe 23 of coil 22, introduces steam into carbonaceous raw material Mixing assembly 25 and distribution assembly 24 of header 14, coal supply stub 26 and joint 28 connecting annular vessel 27 together.

The stated method and the working of the gas generator are as follows.

The original steam enters the serpentine pipe 22 through the short pipe 23 ( FIG. 4 ), and is preheated in the serpentine pipe 22 through the exhaust gas discharge pipe 8 of the generator. 22 Pairs of steam enter the steam distribution assembly 24 via coils where they are split into two streams. Part of the steam enters the mixing assembly 25, and in this assembly 25, the steam will enter the carbon-containing fine raw material through the short pipe 26, such as coal dust, and the obtained steam-coal mixture passes through the short pipe 6, such as an ejector or a gate (not shown in the figure). shown) into the combustion device. The combustion device is a combined burner 4 (Fig. 3) with a diffusion burner 7 for burning liquid or gaseous fuel in the air at its center. The combustion products of the diffusion burner at a temperature of 1500-2000°C are produced by the mixture of the burner 7 The diffuser 19 twists the gas flow core to mix the oxygen flow entering the channel 20 through the branch pipe 5 and the gas-coal mixture entering the channel 21 through the branch pipe 6 .

An important and essential issue in obtaining as much hydrogen as possible in parallel-flow hydrocarbon particle gasification is to resolve several conflicting issues of obtaining the resulting gas through endothermic chemical reactions.

C+H ₂ O＝C+H ₂ –31700 kcal(2)

Simultaneously burning part of the carbonaceous particles in oxygen (in the total flow of steam and oxygen-containing gas) and keeping the temperature of the process in the range of 900-1100°C, the loss of thermal energy is large.

To obtain the desired result, the process first has to be carried out at low pressure (eg close to atmospheric pressure), then the process according to (2) is shifted to the right, according to Le Chatellier's principle. Pricip Le Chatellier argues that in the case of a balanced system subject to external influences, when the factors determining the position of the equilibrium change, the direction of processes in the system that weaken this influence is strengthened. Since reaction (2) produces 2 mol of gas (CO and H ₂ , instead of 1 mol of H ₂ O), the pressure increases as the gas volume increases, reducing the pressure in the reactor can bring the system back to equilibrium, thereby accelerating the reaction (2) to produce CO and _H2 gases. Conversely, when the pressure in the reaction furnace increases, the pressure in the device decreases due to the slowdown of the reaction (2). Technically, this means that while the oxidation process is taking place, pressure build-up must be prevented, i.e. pressure build-up must be prevented. Increased aerodynamic resistance to gas flow must be prevented. Therefore, the design of the oxidation product movement channel should not have a sharp constriction, and the combustion of carbonaceous particles is best carried out in a flow process rather than in a closed chamber.

In order to maintain the necessary high temperature, it is reasonable to burn part of the carbon in oxygen according to the reaction

C+O ₂ =CO ₂ +94300 kcal, (3)

It flows almost instantaneously at 1000 °C and its velocity drops sharply when the temperature is lowered [1, p. 24]. However, maintaining reaction (2) requires a considerable amount of water vapor, what takes away the thermodynamic force, and the heat input of reaction (3) occurs gradually with the combustion of the particles, therefore, it is reasonable to divide the water vapor into 2 parts, Among them, the first part of steam enters through the combustion device, and the second part enters the partially oxidized steam of the raw material into the partial oxidation product flow at the outlet of the oxidation channel. After the carbon-containing raw material particles are burned out, it enters the vertical wall of the gas generator shell and the oxidation channel. the space between the walls. In addition, the separation of the water vapor supply allows a controllable reaction of CO+ _H2O = _CO2 + _H2 +10300 kcal at the outlet of the oxidation channel as follows (1)

With the increase of hydrogen in the generator gas. Since reaction (1) is exothermic, according to Le Chatellier's principle, as the temperature increases, the equilibrium will shift to the left (i.e., toward the original product), but the boundary temperature of this reaction is 1000°C (from the kinetics of the equilibrium constant [3, p. 102] and experimental data [2, p. 30] can be seen). five. Supplying water vapor at the outlet of the oxidation channel will allow the reaction to proceed (1) and reduce the temperature of the gas to 700-800°C and not allow it to rise above 900-1000°C. Therefore, it is best to keep the outlet temperature of the oxidation channel between 800-1000°C.

In order to complete the redox reaction (2) in the partial oxidation channel, its geometry (diameter and length) should ensure that the residence time of the burning particles in the channel is not less than its burnout time (this greatly improves the process efficiency), which in many Much depends on the size of the burning particles. For example, an anthracite particle with a diameter of 100 μm burns in oxygen for 7.1 seconds, and an anthracite particle with a diameter of 50 μm burns in oxygen for 0.413 seconds [3, p. 210]. Knowing the particle size of the gasification raw material and its hourly flow rate, it is easy to calculate the geometric size of the oxidation channel.

The most important condition for the stable operation of gas generators in which particles are gasified in the flow is stable ignition and combustion in the resulting two-phase flow, in which combustion takes place both on the surface of the particles and in the gas phase. For the stability of the process, the propagation speed of the flame must be higher than the speed of the two-phase flow, otherwise the flame will stall and the oxidation process will stop. In known flowing water gasification gas generators, including the recent analog "Prenflo" PDQ, the problem is to increase the combustion rate of coal particles by increasing the oxygen supply and burning more coal in the reaction, thus increasing the process efficiency Pressure and temperature (3). Furthermore, due to the arrangement of the burners perpendicular to the flow, they increase the residence time of the particles in the reactor. It is important in prototyping that the pressure in the oxidation chamber is achieved by constriction at the outlet of the oxidation chamber in the form of a rocket nozzle, which a priori requires liquid deslagging and therefore high temperatures, because otherwise, the narrowed Channels will quickly slag.

In the declared equipment, this problem is solved by the following subject, in order to obtain a constant ignition source and a stable partial oxidation process, the combustion device, preferably integrated in the gas generator cover, is a combined diffusion burner, the center of which Integrated along the axis is the actual diffusion burner for the combustion of gaseous or liquid fuels, consisting of annular channels around which are arranged coaxially, designed to deliver to these annular channels oxygen-containing gases, carbon Hydrogen compounds and water vapour. five. In the proposed method, an additional source of heat for igniting the mixture and maintaining a stable oxidation process comes from the heat of the combustion products of liquid or gaseous fuels from the flow of reactive gas-oxygen mixtures and carbonaceous feedstocks. Such a combustion process scheme can achieve a stable ignition of the two-phase flow, maintain its combustion to a stable reaction heat generation (3), and compensate for the heat loss of the reaction of carbon and carbon monoxide with water vapor. Thermodynamic calculations of this process scheme show that the power of this integrated burner is 10-25% of the carbon power of reaction (3), which is sufficient to obtain a stable process with a temperature in the stream not higher than 1100°C.

Thus, the claimed method enables stable ignition and combustion in a two-phase flow of the particle surface and the gaseous phase through the stable supply of additional thermal energy from the combustion products provided by built-in combustion devices burning liquid or gaseous fuels. The combustion product of the combustion device enters the partial oxidation channel along the channel axis, and mixes with the carbon-containing raw material and the gas-oxygen mixture.

By adjusting the flow of steam, coal and oxygen in the oxidation channel 9 (Fig. 4), the temperature is set at 900-1100°C, tracked by a thermal sensor (not shown in the figure). A second portion of steam from distribution assembly 25 enters steam supply header 12 through line 13 and through opening 15 into the outlet space of oxidation channel 9 where carbon monoxide is reoxidized to carbon dioxide and hydrogen is produced. Calculating the amount of steam should allow the total amount of steam to be cooled to a temperature not higher than 900-1000°C. The reverse reaction is prevented according to formula (1). The generated generator gas is passed through the generator gas discharge pipe 8 for cooling, purification and further processing (eg organic synthesis or membrane separators, further supply of the generated hydrogen for the hydrogenation of coal). Most of the slag and ash produced by coal combustion enter the slag removal chamber 11, from which it is recovered by the slag removal system.

Specific execution example

For the hydrogen production of the coal hydrogenation unit, a prototype of the coal partial oxidation gas generator in Figure 5 was built. Raw coal indicators were determined: ash content on average 12%; humidity 8%; carbon content of the organic part of the coal (WMD) - 77%; hydrogen content WMD 5%. The raw coal is crushed, dried by a drum dryer, and finely ground by a pulverizer. The particle size is less than 100 μm (80% of which is less than 50 μm). The consumption of dry coal is 1 ton per hour.

2. Select an air oxygen generator with a production capacity of 300 meters as the oxygen source 3 per hour or 390 kg per hour.

3. The amount of water for coal oxidation and the distribution ratio of the steam passing through the burner and collector at the outlet of the oxidation channel are selected from the thermodynamic calculation of the heat balance of the oxidation and reduction chemical reactions. The built-in diffusion burner of the combustion device adopts a fuel oil burner with a thermal power of 200kW, and burns 20kg of fuel oil per hour in 20x10.8=216m ³ /hour of air or 276.5kg/hour of air.

4. Send 150 kg of steam per hour to the inlet of the partial oxidation channel through the combustion device. The calculated temperature of the combustion products at the outlet of the partial oxidation channel is 952 °C, which is in line with the optimum temperature limit of 900-1100 °C.

6. The delivery of steam from the manifold (No. 12, Figure 5) is carried out through three rows of holes, the atomization angle between these holes is 120°, and the amount of steam passing through the main pipe (No. 12 in Figure 5) per hour 250-300 kg.

According to the data of 3 temperature sensors installed in front of the outlet of the oxidation channel and the data (3 pieces) of the temperature sensor installed in the annular gap 20 cm higher than the outlet of the oxidation channel between the oxidation channel and the gas generator housing to adjust the passage The amount of steam entering the burner and header.

The selection of the geometry of the partial oxidation channel (No. 9, Figure 6) is determined by the residence time of the combustion products in the oxidation channel. This value is preferably greater than the burn time of the largest feedstock particle. The coal dust particle size in the gas generator is less than 50 microns - 80%, less than 80-90 microns - 20%. The burn time is 0.41 seconds for 50 micron particles and 7 seconds for 100 micron particles. Under complete reaction conditions, coal is obtained in a stream of steam oxygen at a temperature of 1000 °C. That's about 826 liters of gas per second. When the diameter of the partial oxidation channel is 0.85 meters and the length of the oxidation chamber is 6 meters, the residence time of the particles in the oxidation chamber is 7.9 seconds, which exceeds the theoretical combustion time of the largest coal particles.

The average gas (dry) composition under the condition of maximum hydrogen production rate is volume %:

_Н2 – 52.3%

_N2 – 10.0%,

CO – 12.4%,

_CO2 - 25.3%.

The oxygen consumption per ton of dry coal is 300m ³ per hour, and the steam consumption of 1 ton of dry coal is 370-430 kg.

Based on the sources of Shell Copper's technical disclosure prototype installations [4, p. 31], the following average figures can be derived:

_H2 – 25.6%

CO – 65.6%

_CO2 – 0.8%

СН ₄ – 8.0%

The oxygen consumption is 644m ³ per ton of dry coal, and the steam consumption is only about 100 kg per ton of dry coal. Apparently, the proposed method and device have 2 times higher hydrogen production rate, 2 times less oxygen consumption and 1100 °C lower process temperature than the prototype. Compared to the prototype, the process is carried out at a temperature of 1400-1600°C. In the claimed setup, the consumption of water vapor is almost 4 times higher than that of water vapor, but the increase in hydrogen production rate is precisely determined by the decomposition of water.

The given declaration method and specific implementation examples of the declared device show that the hydrogen yield rate of the declared gas generator device is significantly higher than the hydrogen yield index of the prototype machine. At the same time, the total consumption of water vapor for partial oxidation of coal is 370-430 kg per ton of coal. The oxygen consumption is 300 ^m3 per ton of coal. Total hydrogen production is about 65kg per hour, compared to about 32kg per hour for the prototype.

The claimed invention can be widely applied to the gasification of carbonaceous feedstocks, realized in the parallel flow of carbonaceous feedstocks such as coal, lignite, peat, wood, coke, carbon black or other forms of gaseous, liquid or solid fuels or mixtures thereof Efficient gasification to obtain a generator gas with the highest possible hydrogen content. In this case, the required gas parameters can be easily adjusted by changing the consumption of oxygen, steam, gasification feedstock and the power of the built-in burner.

The gas generator can be used in chemical industry, coal chemical industry, petrochemical industry (ammonia, methanol, synthetic fuel, etc.), coke oven gas, electric power and other related industries to process carbon-containing raw materials and produce energy gas and process gas. The high hydrogen content in the industrial gas produced by the declared device will enable refineries to efficiently utilize heavy oil residues and obtain high-quality engine fuel. The declared device can become the main basic device for coal chemical processing in the coal chemical industry. Such devices are equally important for the hydroprocessing of coal and for the production of synthesis gas from coal.

references:

1. Aleshina A.S., Sergeev V.V. Solid Fuel Gasification: Study. allowance. St. Petersburg: Polytechnic Institute Press. year 2010. -202c.

2.Rambush N.E. (translated from English) "Gas Generator"-M.-L.: Gonti, 1939. -413c.

3. Pomerantsev V.V., Arefiev K.V., etc.: "Theoretical Basis of Practical Combustion": Teaching Aids for Higher Schools - L.:

Energoatomizdat, 1986. -312c.

4. Schilling G.-D., Bonne B., Kraus W. Coal Gasification - M.: Nedra, 1986. -175c.

List of Reference Symbols

1. Hull

2. Oxidation chamber

3. Gas generator cover

4. Combustion device

5. Oxygen short tube

6. Water vapor and carbon-containing raw material mixture gas supply short pipe

7. Built-in diffusion burner

8. Generator exhaust pipe

9. Partial Oxidation Channels

10. Oxidation channel heat insulation

11. Deslagging room

12. Lower the steam main.

13. Downpipe

14. Upper steam main

15. Main pipe steam supply hole

16 inlet

17. Fuel supply channel.

18. Ignition electrode

19. Hybrid diffuser

20. Oxygen supply channel

21. Steam supply channel

22. Steam heating coil

23. Inlet coil steam short pipe

24. Steam distribution station

25. Carbon-containing steam mixing device 26. Coal supply branch pipe of coal blending unit.

27. Annular steam heating vessel 28. Circuit breaker for connecting toroidal vessel.

Claims (15)

1. Carbonaceous raw material gasification method, comprises the oxidation chamber partial oxidation of carbonaceous raw material in oxygen-containing gas and steam mixture, it is characterized in that, partial oxidation is carried out in the partial oxidation channel that coaxially arranges in the vertical oxidation chamber, uses The supply of water vapor for the partial oxidation of the carbonaceous feedstock takes place at the inlet and outlet of the partial oxidation channels of the oxidation chamber. 2. The method according to claim 1, characterized in that the partial oxidation is carried out in the mixed flow of oxygen and water vapor in the partial oxidation passage of the oxidation chamber at a temperature of 900-1100°C, provided by the change of the steam volume at the entrance of the partial oxidation passage . 3. The method according to claim 1, characterized in that, at the outlet of the partial oxidation channel, the oxidation chamber is maintained at a temperature between 800-1000°C, provided by the variation of the amount of steam at the outlet of the partial oxidation channel. 4. The method as claimed in claim 1, characterized in that, ignite the carbon-containing raw material mixture and the gas-oxygen mixture and maintain its stable combustion by providing the combustion product to the inlet of the partial oxidation passage from a combustion device installed on the axis of the partial oxidation passage . 5. The method according to claim 1, characterized in that the residence time of the combustion products in the oxidation channels is selected to be greater than the combustion time of the largest raw material particles. 6. The method of claim 1, wherein the geometry of the partial oxidation channel is selected according to the relationship: L≥(4*G*T _b )/(π*ρ(t ₀ )*D ² ), in L - the length of the partial oxidation channel; D - the diameter of the partial oxidation channel; G——A large number of oxidation products enter the partial oxidation channel; _Tb - combustion temperature of the largest particle of carbonaceous raw material; _t0 - the calculated temperature of the oxidation product in the partial oxidation channel; ρ(t ₀ )—the calculated density of oxidation products in the partial oxidation channel. 7. The method according to claim 1, characterized in that solid fuels in the form of coal, lignite, peat, wood, coke, carbon black or gaseous fuels and liquid fuels or mixtures thereof are used as carbonaceous raw materials. 8. A gas generator for gasifying carbonaceous raw materials according to the method of claim 1, comprising a shell, a combustion device, the vertical oxidation chamber, a collector for supplying carbonaceous raw materials, water vapor and oxygen-containing gas, The gasification product discharge pipe and the slag removal chamber are characterized in that it also introduces a partial oxidation channel, which is coaxially arranged in the vertical oxidation chamber and fixed on the part where the combustion device is integrated in the housing upper interior. 9. The gas generator according to claim 8, wherein the upper part of the casing is configured as a detachable cover, and the cover is integrated with a combustion device. 10. The gas generator according to claim 8, wherein the gasification product discharge pipe is installed on a side of the gas generator casing, which is closer to the top of the gas generator. 11. The gas generator as claimed in claim 8, characterized in that it includes upper and lower steam collectors, which adopt a hollow ring design, connected by a downcomer whose axis is parallel to the axis of the shell, and the upper main pipe is installed on the outside of the gas generator cover , the downcomer is installed on the outside of the partial oxidation channel, and the lower steam main pipe is installed at the outlet of the oxidation channel, and is provided with holes for discharging steam into the partial oxidation product stream. 12. The gas generator according to claim 8, wherein the combustion device is configured as a diffusion burner, the diffusion burner has an annular channel, the annular channel is located around the diffusion burner, and the annular channel is surrounded by configured to provide oxygen-containing gas, hydrocarbon feedstock, and water vapor to the annular passage. 13. The gas generator according to claim 8, wherein the inner wall of the oxidation chamber is a coil, the upper lead is connected to the upper steam main pipe through the hot steam distribution assembly, and the lower lead is connected to the external steam generator. 14. The gas generator according to claim 8, characterized in that, the inner wall of the oxidation chamber is configured as a coaxially arranged annular container, and the annular container is configured to be able to move from the bottom of the oxidation chamber to the The cover of the gas generator is supplied with water vapor. 15. The gas generator of claim 8, wherein the partial oxidation passage employs an external thermal insulation.

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