CN115803417A

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

Info

Publication number: CN115803417A
Application number: CN202180039952.2A
Authority: CN
Inventors: 尤里·弗拉基米洛维奇·费先科
Original assignee: You LiFulajimiluoweiqiFeixianke
Current assignee: You LiFulajimiluoweiqiFeixianke
Priority date: 2020-06-05
Filing date: 2021-05-31
Publication date: 2023-03-14
Also published as: WO2021246904A1; US20230203389A1; RU2744602C1; EP4163352A1

Abstract

A method for gasifying carbon-containing raw materials and a gas generator belong to the field of gasification of carbon-containing raw materials, can be used in related industries such as chemical industry, petrifaction, coking, electric power and the like, are mainly used for processing the carbon-containing raw materials to generate energy gas and process gas, and prepare synthesis gas through partial oxidation of carbon-containing flow. In a process for gasifying a carbonaceous feedstock comprising partial oxidation of the carbonaceous feedstock in an oxidation chamber in a mixture of oxygen-containing gas and steam, the partial oxidation is carried out in a partial oxidation channel coaxially mounted in a vertical oxidation chamber, and steam supply for partial oxidation of the carbonaceous feedstock is carried out at the inlet and outlet of the vertical oxidation channel of a combustion chamber, in contrast to known processes. The gas generator comprises a body, a combustion device, a vertical oxidation chamber, a collector for carbon-containing raw materials, water vapor and oxygen-containing gas, a gasification product discharge pipe and a deslagging chamber. The difference is that a partial oxidation channel is further introduced, which is coaxially arranged in the vertical oxidation chamber and attached inside the upper part of the housing in which the burner device is integrated. The method and the device can ensure that the hydrogen content in the industrial gas is high, so that an oil refinery can efficiently utilize the heavy oil residue to obtain high-quality engine fuel, and the device can become a main basic device in the coal chemical industry. Such a plant is also important for the hydroprocessing of coal and the production of synthesis gas from coal.

Description

Method for gasifying carbonaceous material and apparatus for carrying out the method

Technical Field

The invention relates to the related industries of chemical industry, petrifaction, coking, electric power and the like, and can be preferentially used for processing carbon-containing raw materials to generate energy gas and process gas, particularly for gasifying the carbon-containing raw materials and preparing synthesis gas by partially oxidizing carbon-containing flow.

Background

The production of synthesis gas by partial oxidation is currently well known in the art applied. Typically, a carbon (hydrocarbon) containing stream, such as coal, lignite, peat, wood, coke, soot or other forms of gaseous, liquid or solid fuels or mixtures thereof, is partially combusted in the gasification reactor, i.e. in the gasification reactor. Partial oxidation is carried out using an oxygen-containing gas, such as nearly pure oxygen or air that is not necessarily oxygen-rich, to obtain a syngas (i.e., CO and H) ₂ ) Product stream and CO ₂ 。

The coal gasification technology is mainly divided into three types: fixed bed gas generators, such as those produced by Lurgi, germany. Frankfurt [1, pages 161-167 ] fluidized bed or fluidized bed gasifier in the meidue river, using parallel flow gasifiers of "U-Gas", "Winkler" (american, chicago Gas technology institute) [1, pages 167-173 ] and "shell" (shell and UHDE co-production, dutch Buggenum unit) [1, pages 189-191 ] and "german guy" (american, german guy GP, cool Water and Polk unit) [1, pages 176-180 ].

The fixed bed gasifier has the disadvantages of low processing capacity of a single device, expensive synthesis gas and water processing systems and the like, and also has the problem of operation safety.

The fluidized bed gas producer has low efficiency due to low carbon conversion rate, difficult discharge of dry bottom ash, high fly ash entrainment and the like.

The above disadvantages are not present when a parallel flow gasification process is employed. In parallel flow gasification plants, almost all types of carbonaceous feedstocks can be partially oxidized to give industrial gases with defined properties. In addition, the gasifier is small and provides a high gasification feedstock yield.

Disadvantages of the parallel flow gasification process include:

1. gasification of any type of solid and liquid fuel in parallel streams can only be effected with fine atomization, typically with particle sizes less than 75 microns. In this case, the large fraction of the feed particles can significantly reduce the process efficiency and the quality of the resulting gas.

2. In the gasification of solid and liquid fuels, in order to obtain industrial gases (water vapor, synthesis gas and mixtures thereof) with the highest hydrogen yields, it is necessary to oxidize the feedstock with steam or steam-oxygen mixtures, which causes problems in the ignition of the mixture while maintaining the necessary optimum process temperature around 900-1100 ℃ [2, pages 26-27, page 31 ].

A schematic diagram of a gas generator operated by the "Koppers-Totzek" method is known [1, pages 174 to 176 ], in which the gasification is carried out at atmospheric pressure. According to the Koppers-Totzek process, the ground and dried fuel, which is specially prepared, enters a fuel silo, from where it is fed with a metering screw into a mixing nozzle and then into an oval reaction chamber consisting of two to four mutually opposed combustion mixing nozzles. In the combustion nozzle, the pulverized fuel is mixed with oxygen and water vapor, which forms a steam jacket outside the pulverized oxygen torch, thereby protecting the reaction chamber refractory lining from slagging, erosion, and high temperatures inside the flame. The combustion temperature inside the torch was 1500-1700 ℃, the temperature level being maintained according to the melting temperature of the ash. The ash in liquid form is removed from the bottom of the reaction chamber to a special device where it is cooled and granulated. The disadvantages of this gasifier include:

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

2. a reduction in hydrogen yield due to high temperature;

3. safety is low, 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 requirements of the gas generator construction on structural materials are increased.

The "Destec" coal gasification process is also well known, with the aim of expanding the fuel base by shifting from natural gas to coal, originally developed by the dow chemical company [1, pages 180-183 ]. Aiming at coal gasification, a two-stage flow type liquid slag-discharging gas producer is developed. The fuel is fed to the reactor in the form of a coal-water slurry (coal/water = 60/40%) under high pressure generated by a pump. The gasifying agent uses high-purity oxygen (95%) produced by a special device. The working pressure of the gasification furnace is 2.75MPa, and the temperature is 1371 ℃. However, the process temperature depends on the type of fuel used, and when more refractory ash is present, the process temperature increases due to slagging. The coal-water slurry is fed to the bottom of the gasifier while being mixed with oxygen. The coal is partially oxidized to provide a thermal endothermic reaction in the gasification zone. The slag produced in the first stage is discharged to a water tank and then used for construction. The gas of the crude generator set enters the lining part at the upper part of the reactor, and the coal water slurry is also introduced into the lining 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 is raised and the endothermic reaction cools it to around 1038 ℃.

The disadvantages of this gas generator include:

1. the coal water slurry has process problems in the using process;

2. high temperature and pressure results in a decrease in hydrogen yield;

3. the yield of the carbon dioxide is improved, and compared with other direct current gasification furnaces (namely, the generated heat is lower than that of the same gas);

5. High-purity oxygen is used as a gasifying agent.

The presnflo (pressurized exhausted-Flow) steam generation process from Tyssenkrupp AG, also known as "presnflo" (presnflo), operates under pressure on any type of solid fuel (coal, petroleum coke, biomass). The procedure is based on the "Koppers-Totzek" technique. In the gas generator, the prepared fuel is gasified under a pressure of about 4 MPa.

The gasification temperature is higher than ash melting point (1400-1600 deg.C), and slag tapping can be performed. The advantage of this process is the dry supply of the gasified feedstock fuel. Fine coal (80% by volume less than 0.1 mm) is supplied together with oxygen and steam through four burners located at the same level at the bottom of the gasifier. The disadvantages of this gas generator include:

1. due to the high temperature and pressure, the hydrogen yield is reduced (in the chemical industry, only where the requirements on the hydrogen content of the process gas are not high);

2. the high temperature and pressure result in higher demands on the materials used in the construction of the gas generator and high financial costs for manufacturing the gas generator.

The utility model is also called a carbon-containing feed gasifier (Ru No. 2237079, ipc 10J3/20, 2004, 9/27), which belongs to a carbon-containing raw material gas generator and can be used for processing carbon-containing raw materials in chemical industry, petrochemical industry, coke oven gas, electric power and other related industries to produce energy source gas and process gas. The gasification furnace comprises a vertical gasification chamber, a burner for conveying carbonaceous raw materials and oxygen-containing gas, a water vapor manifold, a nozzle for conveying carbonaceous powdery raw materials, a gasification product discharge pipe (at the bottom of the gasification chamber), and a deslagging chamber, and is also provided with a special unit which consists of the burner arranged at the center of the unit above the gasification chamber and the nozzle arranged around the burner at the periphery of the unit above the gasification chamber so as to generate a steam curtain and protect the lining of the gasification chamber from overheating. The gasification chamber is a cylindrical pipe ending in a conical deslagging chamber, wherein the gasification chamber is conditionally decomposed into an oxidizing part and a reducing part. The process temperature in the oxidation zone is 1500-3000 deg.C, and in the reduction zone, the temperature is reduced to 1000-1600 deg.C by supplying steam.

The disadvantages of this gas generator include:

1.a decrease in hydrogen yield due to high temperature;

2. when using a gasifier as a thermal energy source, the plant efficiency decreases, since the presence of free hydrogen and high content of carbon monoxide indicates incomplete combustion.

3. The location of the bottom exhaust pipe of the gasifier determines the amount of slag and ash entering the flue and gas distribution system, which can lead to rapid failure of the gasifier.

It is known that the gasification process in the "Prenflo" PDQ gas generator from Thisen Krupp corporation is considered the closest process [1, pages 186-189 ], more advanced than its predecessor "Prenflo" PSG, which operates as the "Koppers-Totzek" process. The gas generator gasifies fine coal dust mixed by oxygen and water vapor in a vertical oxidation chamber at the temperature of 1400-1600 ℃. The oxidation of the coal takes place in practice under adiabatic conditions, since the oxidation chamber is a channel coaxial with the outer wall of the gasifier, separated from the outer wall by an annular space washed by the oxidation products of the coal, keeping the temperature of the oxidation chamber between 1400 and 1600 ℃. The mixture of coal dust and oxygen with water vapor was fed through 4 horizontal burners at the top of the oxidation chamber. The oxidation chamber enters a rapid water cooling chamber, water is injected into the rapid water cooling chamber through an annular hole in the cooling chamber, and the oxidation product is cooled to the temperature of 200-250 ℃.

The closest to the reporting device is the gasifier [1], which implements the prototype method, comprising a main pipe for supplying steam and oxygen to the burners, a main pipe for supplying the gas-coal mixture to the burners, an oxidation chamber entering a rapid water cooling chamber, which is a cylindrical tube placed coaxially inside the gasifier housing, ending in a conical deslagging chamber. An annular gap is arranged between the deslagging chamber and the central pipe of the quick cooling chamber, and the oxidized gas generator and the water vapor leave the cooling chamber through the annular gap, then rise along the gap between the cooling chamber pipe and the wall of the shell of the gas generator, leave the gas generator and enter a gasification product discharge pipe for further treatment.

The rapid cooling chamber has a sharp change in gas flow, so that the gas moves downward after passing through a gap between a cooling chamber pipe and a slag removal chamber to move upward, thereby enabling a large amount of slag and ash to be separated and enter the conical slag removal chamber. The deslagging chamber is connected with a deslagging system.

The slag of the gasification furnace can be used as a building material.

The disadvantages of this gas generator include:

1. the hydrogen yield is reduced due to the high temperature and pressure (in the chemical industry, these gas generators are only used where the hydrogen content of the process gas is not highly required). The total amount of hydrogen does not exceed 22-32% (same as all direct current gasifiers, based on the Koppers-Totzek technology (shell-copper process), whereas for the Lurgi stratified gasifiers the hydrogen content in the dry gas is 36-40%, and for the Winkler fluidized bed gasifier [1, pages 169-170 ], the hydrogen content is between 35-45% (page 4, page 30).

3. Increase in oxygen consumption per ton of gasified coal, all Koppers-Totzek (540-650 meters) ³ ) Whereas for a stratified gas generator, lurgi is 220-300 meters ³ And 350m for a winkler fluidized bed gas generator ³ [4, pages 30 to 33 ]]。

4. In order to ensure stable ignition and to maintain stable combustion of the mixture, in addition to increasing oxygen consumption, the oxidation chamber also employs a horizontal burner arrangement, which does not allow to reduce the process temperature to 900-1100 ℃ (the optimum temperature for syngas production), since at such temperatures (900-1100 ℃), most of the ash of the coal is in the solid phase, which means that the ash may accumulate on the combustion chamber walls, leading to slagging and further failure of the gas generator.

5. Cooling the gas to a temperature of 200-250 c too rapidly does not allow additional hydrogen to be generated by the reaction

CO+H ₂ O＝CO ₂ +H ₂ +10300 kilocalorie (1)

Since the water vapour decomposition has been reduced by an order of magnitude from 1000 ℃ at a temperature of 800 ℃, the conversion of water vapour at 800 ℃ will be only 0.5% of the conversion at 1000 ℃ within 1 second for the same residence time and contact time [2, page 29 ]. This means that at lower temperatures there is no reaction at all, as evidenced by the equilibrium constant (1) for this reaction increasing at 500 ℃ by a factor of 100 over 1000 [3, page 102 ].

Disclosure of Invention

The main task of the present invention is to provide an efficient process for gasification in parallel flows of carbonaceous feedstocks, such as coal, lignite, peat, wood, coke, carbon black or other forms of gaseous, liquid or solid fuels, or mixtures thereof, a process for the partial oxidation of hydrocarbon feedstocks in a mixture of oxygen-containing gases and water vapor and an apparatus for carrying out the process, in order to obtain a hydrogen yield as high as possible in the gasification of carbonaceous feedstocks.

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

The claimed technical result is achieved by: in a known process for gasifying a carbonaceous feedstock, the carbonaceous feedstock is partially oxidized in an oxidation chamber in a mixture of an oxygen-containing gas and steam, the partial oxidation being carried out in a partial oxidation channel coaxially mounted in the oxidation chamber, and the steam supply for the partial oxidation of the carbonaceous feedstock being carried out at the inlet and outlet of the partial oxidation channel of the combustion chamber.

The partial oxidation is optimally carried out in a mixed flow of oxygen and water vapour in the partial oxidation channels of the oxidation at a temperature of 900-1100 ℃, provided by a variation of the steam quantity at the inlet of the partial oxidation channels.

The temperature of the outlet of the partial oxidation channel of the oxidation chamber is feasible to be controlled within the range of 800-1000 ℃, and is provided by the change of the steam quantity at the outlet of the partial oxidation channel.

It is possible to ignite and maintain a stable combustion of the carbonaceous feedstock and the steam-oxygen mixture by feeding combustion products to the inlet of the partial oxidation channel through combustion means mounted along the axis of the partial oxidation channel.

The residence time of the combustion products in the oxidation channel is preferably selected to be 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 ),

wherein

L-partial oxidation channel length;

d-diameter of partial oxidation channel;

g-a large amount of oxidation products enter a partial oxidation channel;

T _b -the combustion temperature of the largest particles of carbonaceous feedstock;

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

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

Solid fuels such as coal, lignite, peat, wood, coke, soot, etc., or gaseous and liquid fuels, or mixtures thereof, may be used as the carbonaceous feedstock.

The technical result is also that a gas generator for gasifying carbonaceous starting materials is known, comprising a housing, a combustion device, a vertical oxidation chamber, a carbonaceous starting material, a collector for water vapour and oxygen-containing gas, a discharge pipe for the gasification products, a deslagging chamber, and a partial oxidation channel which is arranged coaxially in the vertical oxidation chamber and is fixed on the upper inner side of the housing, the partial oxidation channel integrating the 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 gasifier shell, which is closer to the top of the gasifier.

The gasification furnace for gasifying the carbonaceous material is optimally designed, the furnace comprises an upper steam main pipe and a lower steam main pipe, the upper steam main pipe and the lower steam main pipe adopt a hollow annular design and are connected by a descending pipe, the axis of the descending pipe is parallel to the axis of a shell, the upper steam main pipe is arranged outside a gas generator cover, the descending pipe is arranged outside a partial oxidation channel, the lower steam main pipe is arranged at an outlet of the oxidation channel and is provided with a hole for discharging steam into a partial oxidation product flow.

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

The inner wall of the oxidation chamber is reasonably designed into a coil, the upper end of the coil is connected with an upper-end steam main pipe through a hot steam distribution assembly, and the lower end of the coil is connected with an external water steam generator.

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

The partial oxidation tunnel may be performed with external thermal insulation.

The so-called process and the plant for the gasification of carbonaceous feedstocks, such as coal, lignite, peat, wood, coke, soot or other forms of gaseous, liquid or solid hydrocarbon fuels or mixtures thereof, are not known from the prior art, and therefore the so-called solution complies with the patentability conditions of the Novizn invention.

An analysis of the state of the art as to whether the declared solution meets the "invention level" invention patentability conditions is shown below.

In the proposed process for gasification of carbonaceous materials, such as coal, lignite, peat, wood, coke, soot or other forms of gas, the partial oxidation of liquid or solid propellants or mixtures thereof in a mixture of oxygen-containing gas and steam is carried out to maximize the production of hydrogen by means of a partial oxidation process, which, unlike known plants, is in fact divided into two stages: first, under adiabatic conditions, at an optimum temperature of 900-1100 deg.C, under adiabatic conditions, under adiabatic conditions, the partial oxidation is carried out in a mixed flow of oxygen and water vapour under adiabatic conditions, and the resulting gas is then oxidized separately with water vapour at the outlet of the partial oxidation channels, maintaining the temperature of this zone within the optimum temperature range of 800-1000 ℃. In the proposed apparatus, all processes are carried out under conditions which prevent a sharp increase in the pressure in the reaction space, unlike analogous apparatuses, in order to carry out the oxidation process. Furthermore, the claimed method allows stable ignition and combustion in the two-phase flow obtained in the particle surface and gas phase by a stable input of additional thermal energy from the combustion products of an in-built combustion device burning liquid or gaseous fuel. The combustion products of the combustion apparatus enter the partial oxidation channel along the channel axis and mix with the carbonaceous feedstock and the steam-oxygen mixture.

In this case, the combustion device maintains the stability of ignition and the maintenance of the necessary temperature in the oxidation channels by the thermal energy input built in from the upper portion of the gasifier shell when any fuel is burned, regardless of whether or not carbon feedstock enters the gasifier for oxidation. For example, unlike prototypes and other known means, oxygen in air is maintained stable by high oxygen consumption to burn partially oxidizable carbonaceous feedstock, where high temperatures of 1400-1600 ℃ are generated at pressures of 27-40atm, and thus hydrogen yield is reduced. Running the process at optimum gasification conditions and temperatures allows the use of low cost materials in the design of the gasifier, while the burner in the prototype is mounted on the vertical axis of the gasifier (high temperatures result when the combustion product streams collide). Thus, the claimed group of inventions meets the "invention level" condition.

Drawings

The method and apparatus for gasifying a carbonaceous feedstock are illustrated in the accompanying drawings, in which

FIG. 1 shows an overall scheme of a gasifier for gasification of a carbonaceous feedstock;

FIG. 2 illustrates a cross-sectional view of the gas generator;

FIG. 3 illustrates a schematic diagram of a gas producer combustion arrangement;

FIG. 4 shows a schematic of a coil gasifier for steam preheating and shell wall cooling;

figure 5 shows a schematic diagram of a set of ring-shaped containers for heating steam and cooling the walls of the gas generator.

Detailed Description

The gas generator claimed for gasifying carbonaceous feedstock comprises a housing 1, an oxidation chamber 2, a housing cover 3 (fig. 1), a combustion device 4 (fig. 4), supply branches 6 with diffusion burners 7, a mixture of oxygen and water vapor with the carbonaceous feedstock, tubes 8 for discharging the generator gas, partial oxidation channels 9 with a thermal insulation 10, a main pipe 12 at the outlet of the oxidation channels 9 for feeding steam to the space, and a downcomer 13 (fig. 2), feeding steam from an upper steam main pipe 14 to the steam main pipe 12. The lower part of the shell is provided with a deslagging chamber 11.

Fig. 2 providesbase:Sub>A cross-sectional viewbase:Sub>A-base:Sub>A (fig. 1) of the gas generator showing the arrangement of the steam supply ports 15 in the steam supply main 12. Fig. 3 shows a schematic view of a combustion device 4 with a built-in diffusion burner 7, an air supply channel 16, a fuel supply channel 17 (e.g. fuel oil or gaseous fuel), an ignition electrode 18, a mixing diffuser 19, an oxygen supply channel 20 and a steam supply channel 21. Figure 4 provides a schematic illustration of the gasifier of figure 1 with the addition of steam preheating and heat insulating cooling coils 22 to the gasifier shell 1, with steam being introduced into the coils 22, steam distribution assembly 24 being introduced into the steam mixing assembly and header 14 of the carbonaceous feedstock 25, and coal being introduced into the mixing assembly 26. Fig. 5 provides a schematic illustration of the gasifier of fig. 1, with the addition of an annular steam preheating vessel 27 and a heat-insulated cooling vessel 27 of the gasifier shell 1, a short pipe 23 for introducing steam into the coil 22, a distribution assembly 24 for introducing steam into the carbonaceous feedstock mixing assembly 25 and the manifold 14, a coal supply short pipe 26 and a fitting 28 connecting the annular vessels 27 together.

The method and the gas generator stated operate as follows.

The raw steam enters the coil 22 via a short pipe 23 (fig. 4) and is preheated in the coil 22 by the generator exhaust gas discharge pipe 8. The pair of steam 22 enters the steam distribution assembly 24 through the serpentine tubes where it is split into two streams. Part of the steam enters a mixing assembly 25 in which assembly 25 the steam passes carbonaceous fines, such as coal dust, entering through a pipe spool 26 and the resulting steam-coal mixture passes through a pipe spool 6, such as an eductor or a sluice (not shown), to a combustion device. The combustion device is a combi-burner 4 (fig. 3) centrally provided with a diffusion burner 7 for burning liquid or gaseous fuel in air. The combustion products of the 1500-2000 c temperature diffusion burner produce a core of air flow twisted by the mixing diffuser 19 of burner 7, mixing the oxygen flow entering channel 20 through branch 5 and the steam coal mixture entering channel 21 through branch 6.

An important and indispensable problem in obtaining as much hydrogen as possible in a parallel flow hydrocarbon particle gasification process is solving several conflicting problems, namely obtaining the product gas by an endothermic chemical reaction.

C+H ₂ O＝C+H ₂ -31700 kcal (2)

While combusting part of the carbonaceous particles in the oxygen (in the combined stream of steam and oxygen-containing gas) and maintaining the temperature of the process in the range of 900-1100 c, the heat energy loss is large.

To achieve the desired result, the process must first be run at low pressure (e.g., near atmospheric pressure) and then moved to the right according to the process of (2) in accordance with Le Chatellier's principle. Pricip Le Chatellier states that in the case of a balancing system subject to external influences, when the factors determining the position of the balance change, the direction of the process in the system attenuating such influences is intensified. 2mol of gas (CO and H) are produced as a result of reaction (2) ₂ Instead of 1mol of H ₂ O), as the gas volume increases, decreasing the pressure in the reactor will allow the system to return to equilibrium, thereby accelerating the production of CO and H by reaction (2) ₂ A gas. On the contrary, when the pressure in the reaction furnace increases, the pressure in the apparatus decreases due to the slowing of the reaction (2). Technically, this means that when the oxidation process is carried out, a pressure increase has to be prevented, i.e. has to be prevented. The aerodynamic resistance to gas flow must be prevented from increasing. Thus, the design of the oxidation product moving path should not be so sharply constricted that combustion of the carbonaceous particles preferably occurs during flow rather than in a closed chamber.

In order to maintain the necessary high temperature, it is advisable to burn part of the carbon in oxygen, depending on the reaction

C+O ₂ ＝CO ₂ +94300 kilocalorie (3)

Almost instantaneous flow at 1000 ℃ and its velocity drops sharply when the temperature decreases [1, page 24 ]]. However, it is reasonable to divide the heat input of reaction (3) into 2 portions, in which a first portion of steam enters through the combustion device and a second portion of steam entering the partial oxidation of the feedstock enters the partial oxidation product stream at the outlet of the oxidation channel and, after the carbonaceous feedstock particles are burned out, enters the space between the vertical wall of the gasifier shell and the wall of the oxidation channel, what carries away the heat power, and a considerable amount of steam is required to sustain reaction (2). Furthermore, the separation of the steam supply allows the CO + H to be carried out at the outlet of the oxidation channel ₂ O＝CO ₂ +H ₂ +10300 kcal, as shown in formula (1)

With an increase in hydrogen in the generator gas. Since reaction (1) is exothermic, according to Le Chatellier's principle, equilibrium will shift to the left (i.e. towards the original product) when the temperature increases, but the boundary temperature of the reaction is 1000 ℃ (as can be seen from kinetics of equilibrium constants [3, page 102 ] and experimental data [2, page 30 ]). And fifthly. The supply of steam at the outlet of the oxidation channels will allow the reaction (1) to proceed and reduce the gas temperature to 700-800 c without allowing it to rise above 900-1000 c. Therefore, it is preferable to maintain the outlet temperature of the oxidation channel between 800 and 1000 ℃.

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 combustion particles in the channel is not less than its burnout time (which greatly increases the efficiency of the process), which depends to a large extent on the size of the combustion particles. For example, anthracite coal particles with a diameter of 100 microns burn in oxygen for 7.1 seconds, and anthracite coal particles with a diameter of 50 microns burn in oxygen for 0.413 seconds [3, p 210 ]. Knowing the particle size of the gasification feedstock and its hourly flow rate, it is easy to calculate the geometric dimensions of the oxidation channels.

The most important condition for the stable operation of a gasifier where particles are gasified in a stream is the stable ignition and combustion in the resulting two-phase flow, where combustion takes place both on the particle surface and in the gas phase. For process stabilization, the flame propagation velocity must be higher than the two-phase flow velocity, otherwise the flame will stall and the oxidation process will stop. In known flowing water gasification gasifiers, including the recent analogue "Prenflo" PDQ, this problem is to increase the combustion rate of the coal particles by increasing the oxygen supply and burning more coal in the reaction, thereby increasing the pressure and temperature of the process (3). Furthermore, they increase the residence time of the particles in the reactor due to the arrangement of the burners perpendicular to the flow. It is important in the prototype design that the pressure in the oxidation chamber is achieved by a constriction at the exit of the oxidation chamber in the form of a rocket nozzle, which a priori requires liquid deslagging and therefore high temperatures, since otherwise the narrowing channel would quickly become fouled.

In the claimed apparatus, this problem is solved by the subject-matter that, 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, whose center is integrated along the axis with the actual diffusion burner for burning gaseous or liquid fuel, which diffusion burner consists of an annular channel, which is arranged coaxially around the annular channel and which is designed to feed oxygen-containing gas, hydrocarbons and water vapor to these annular channels. And fifthly. In the proposed method, the additional heat source for igniting the mixture and maintaining a stable oxidation process is derived from the heat of the combustion products of the liquid or gaseous fuel, which combustion products are derived from the flow of the reactive steam-oxygen mixture and the carbonaceous feedstock. Such a combustion process scheme can achieve a stable ignition of the two-phase flow, maintaining its combustion to a stable heat of reaction (3), compensating for heat losses from the reaction of carbon and carbon monoxide with water vapor. Thermodynamic calculations for this process scheme indicate that the power of this integrated burner is 10-25% of the power of the reaction (3) carbon, sufficient to obtain a stable process with a temperature in the stream not higher than 1100 ℃.

Thus, the claimed method enables stable ignition and combustion in a two-phase flow of particle surface and gas phase by stably providing additional thermal energy from the combustion products provided from an in-built combustion device combusting liquid or gaseous fuel. The combustion products of the combustion apparatus enter the partial oxidation channel along the channel axis and mix with the carbonaceous feedstock and the steam-oxygen mixture.

The temperature was set to 900-1100 c by adjusting the flow of steam, coal and oxygen in the oxidation channel 9 (fig. 4), followed by a thermal sensor (not shown). A second portion of the steam from the distribution assembly 25 enters the steam supply header 12 through conduit 13 and enters the outlet space of the oxidation tunnel 9 through opening 15 where the carbon monoxide is re-oxidized to carbon dioxide and hydrogen is produced. The amount of steam is calculated so that the total amount of steam is cooled to a temperature of not more than 900-1000 ℃. The reverse reaction is prevented according to equation (1). The generated generator gas is passed via a generator gas discharge pipe 8 to cooling, cleaning and further processing (for example, organic synthesis or membrane separators, the generated hydrogen being further supplied to the hydrogenation of the coal). Most of the slag and ash produced by the combustion of the coal enters the slagging chamber 11 from which it is recovered by a slagging system.

Concrete examples of execution

A model gas producer model machine of the coal partial oxidation shown in figure 5 is set up for producing hydrogen by a coal hydrogenation device. The raw coal indexes are determined: the ash content is 12% on average; humidity is 8%; carbon content of the organic portion of coal (weapons of mass destruction) -77%; the hydrogen content of a weapons mass destruction is 5%. The raw coal is crushed, dried by a drum dryer and finely ground by a grinder, and the particle size is less than 100 mu m (80% of the particle size is less than 50 mu m). The consumption of dry coal was 1 ton per hour.

2. An air oxygen plant with a capacity of 300 meters was selected as the oxygen source for 3 kg per hour or 390 kg per hour.

3. The amount of water for the oxidation of coal and the distribution ratio of steam at the outlet of the oxidation tunnel through the burner and collector are selected from thermodynamic calculations of the heat balance of the oxidation and reduction chemical reactions. The diffusion burner in the combustion device adopts a fuel oil burner with the thermal power of 200kW, and the thermal power is 20x10.8=216m ³ Air/hr or 276.5 kg/hr20kg of fuel oil were burned in the air per hour.

4. 150 kg/hour of steam was fed to the inlet of the partial oxidation channel via a burner. The calculated temperature of the combustion products at the outlet of the partial oxidation channel is 952 ℃, which corresponds to the optimal temperature limit of 900-1100 ℃.

6. The delivery of steam from the manifold (position No. 12, fig. 5) was through three rows of holes with an atomization angle of 120 ° between the holes and a steam mass of 250-300 kg per hour through the header (position No. 12, fig. 5).

The amount of steam entering through the burner and the manifold is regulated on the basis of the data of 3 temperature sensors installed before the outlet of the oxidation tunnel and the data of the temperature sensor (3) installed in the annular gap between the oxidation tunnel and the gas generator housing 20 cm above the outlet of the oxidation tunnel.

The choice of the geometry of the partial oxidation channel (position 9, fig. 6) is determined by the residence time of the combustion products in the oxidation channel. This value is preferably greater than the combustion time of the largest raw material particles. The grain diameter of coal dust in the gas generator is less than 50-80 percent and less than 80-90-20 percent. The burning time for 50 micron particles was 0.41 seconds and for 100 micron particles was 7 seconds. Under the conditions of complete reaction, coal was obtained in a stream of steam oxygen at a temperature of 1000 ℃. Approximately 826 liters of gas per second. When the diameter of the partial oxidation channel is selected to be 0.85 meter and the length of the oxidation chamber is selected to be 6 meters, the residence time of the particles in the oxidation chamber is 7.9 seconds, which exceeds the theoretical combustion time of the coal particles with the maximum particle size.

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

Н ₂ –52.3％

N ₂ –10.0％，

CO–12.4％，

CO ₂ –25.3％。

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

From the data source [4, page 31 ] of the technical disclosure prototype device of copper shell company, the following average numbers can be derived:

H ₂ –25.6％

CO–65.6％

CO ₂ –0.8％

СН ₄ –8.0％

the oxygen consumption is 644m ³ The steam consumption of each ton of dry coal is only about 100 kg. It is clear that the hydrogen yield of the proposed method and apparatus is 2 times higher than the prototype, the oxygen consumption is 2 times lower and the process temperature is 1100 deg.c lower. Compared to the prototype, the process was carried out at a temperature of 1400-1600 ℃. In the claimed device, the water vapor consumption is almost 4 times the water vapor consumption, but the increase in hydrogen yield is determined by the decomposition of water.

The specific examples of implementation of the proposed reporting method and device show that the hydrogen yield results of the reported gas generator device are significantly higher than the prototype hydrogen yield index. Meanwhile, the total consumption of steam for the partial oxidation of the coal is 370-430 kg per ton of coal. Oxygen consumption of 300m ³ Per ton of coal. The total hydrogen production was about 65 kg per hour, while the prototype was about 32 kg per hour.

The claimed invention can be widely applied to the gasification of carbonaceous feedstocks, achieving an efficient gasification in parallel flows of carbonaceous feedstocks such as coal, lignite, peat, wood, coke, carbon black or other forms of gaseous, liquid or solid fuels or mixtures thereof, to obtain a generator gas with as high a hydrogen content as possible. In this case, the required gas parameters can be easily adjusted by varying the oxygen, steam, consumption of gasification raw materials and the power of the internal burner.

The gas generator can be used in the related industries of chemical industry, coal chemical industry, petrochemical industry (ammonia, methanol, synthetic fuel and the like), coke oven gas, electric power and the like, and can be used for processing carbon-containing raw materials and producing energy source gas and process gas. The hydrogen content in the industrial gas generated by the declaration device is high, so that an oil refinery can efficiently utilize heavy oil residues to obtain high-quality engine fuel, and the declaration device can be used as a main basic device for coal chemical processing in the coal chemical industry. Such a plant is also important for the hydroprocessing of coal and for the production of synthesis gas from coal.

Reference:

aleshina a.s., sergeev v.v. solid fuel gasification: and (5) learning. Jin Tie. St. Peterberg: institute of technology publishers. In 2010. 202c.

Rambus n.e. (translated from english) "gas generator" -m. -l.: gonti, 1939. -413c.

Pomerantsev V.V., arefev K.V., etc.: practical combustion theory basis: teaching aid in higher schools-L.:

energotomizdat, 1986. -312c.

Schilling g. -d., bonne b., kraus w. "coal gasification" -m.: nedra, 1986. 175c.

List of reference symbols

1. Boat hull

2. Oxidation chamber

3. Gas generator cover

4. Combustion apparatus

5. Oxygen supply short pipe

6. Short supply pipe for mixed gas of steam and carbon-containing raw material

7. Built-in diffusion burner

8. Generator exhaust gas discharge pipe

9. Partial oxidation channel

10. Oxidation tunnel insulation

11. Slag removal chamber

12. A lower steam main.

13. Down pipe

14. Upper steam main pipe

15. Main pipe steam supply hole

16 air inlet channel

17. A fuel supply passage.

18. Ignition electrode

19. Mixing diffuser

20. Oxygen supply channel

21. Steam supply channel

22. Steam heating coil

23. Steam short pipe of coil inlet pipe

24. Steam supply distribution station

25. A carbonaceous steam mixing device 26, a coal supply branch pipe of the coal blending unit.

27. And the annular steam heating container 28 is used for connecting a circuit breaker of the annular container.

Claims

1. Process for the gasification of a carbonaceous feedstock comprising partial oxidation of the carbonaceous feedstock in a mixture of oxygen-containing gas and water vapour, characterized in that the partial oxidation is carried out in a partial oxidation channel arranged coaxially in a vertical oxidation chamber, and that the supply of water vapour for the partial oxidation of the carbonaceous feedstock is carried out at the inlet and outlet of the partial oxidation channel of the oxidation chamber.

2. The method of claim 1 wherein the partial oxidation is carried out in a mixed flow of oxygen and water vapor in an oxidation partial oxidation pass at a temperature of 900 to 1100 ℃, provided by a change in the amount of steam at the inlet of the partial oxidation pass.

3. The method of claim 1 wherein the oxidation chamber is maintained at a temperature of between 800 ℃ and 1000 ℃ at the outlet of the partial oxidation tunnel, provided by a variation in the amount of steam at the outlet of the partial oxidation tunnel.

4. The method of claim 1 wherein the mixture of carbonaceous feedstock and the mixture of steam and oxygen is ignited and maintained in stable combustion by supplying combustion products from a combustion device mounted on the axis of the partial oxidation tunnel to the inlet of the partial oxidation tunnel.

5. The method of claim 1, wherein the residence time of the combustion products in the oxidation channel is selected to be greater than the combustion time of the largest feedstock 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 ),

wherein

L-partial oxidation channel length;

d-diameter of partial oxidation channel;

g, enabling a large amount of oxidation products to enter a partial oxidation channel;

t ₀ -a calculated temperature of the oxidation products in the partial oxidation channel;

ρ(t ₀ ) -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 the carbonaceous feedstock.

8. Gasifier for the gasification of carbonaceous feedstocks according to the process of claim 1, comprising a shell, a combustion device, said vertical oxidation chamber, a collector for the supply of carbonaceous feedstock, water vapour and oxygen-containing gas, a discharge conduit for the gasification products and a deslagging chamber, characterized in that it also incorporates a partial oxidation channel, which is arranged coaxially in said vertical oxidation chamber and is fixed inside the upper part of said shell integrated in said combustion device.

9. The gas generator as claimed in claim 8, wherein the upper part of the housing is configured as a detachable cover, which integrates a combustion device.

10. The gas generator of claim 8 wherein the gasification product discharge tube is mounted on a side of the gas generator housing that is closer to the top of the gas generator.

11. The gas generator of claim 8, comprising upper and lower steam collectors of hollow annular design connected by a downcomer having an axis parallel to the axis of the housing, the upper header being mounted outside the gas generator cover, the downcomer being mounted outside the partial oxidation path, and the lower steam header being mounted at the outlet of the oxidation path and being provided with holes for discharging steam into the partial oxidation product stream.

12. The gas generator of claim 8, wherein the combustion device is configured as a diffusion burner having an annular channel positioned about the diffusion burner, the annular channel being configured to provide an oxygen-containing gas, a hydrocarbon feedstock, and steam to the annular channel.

13. The gas generator of claim 8 wherein the inner walls of the oxidation chamber are coiled tubes with upper leads connected to the upper steam manifold through the hot steam distribution assembly and lower leads connected to the external water vapor generator.

14. The gas generator of claim 8, wherein the inner wall of the oxidation chamber is configured as a coaxially arranged annular container configured to be able to supply water vapor from the bottom of the oxidation chamber to the cover of the gas generator.

15. The gas generator of claim 8 wherein the partial oxidation channel employs an external thermal insulation layer.