WO2020192221A1

WO2020192221A1 - Supercritical gasification device and method

Info

Publication number: WO2020192221A1
Application number: PCT/CN2019/129801
Authority: WO
Inventors: 楼龙春
Original assignee: 楼龙春
Priority date: 2019-03-27
Filing date: 2019-12-30
Publication date: 2020-10-01
Also published as: CN109810728B; CN109810728A

Abstract

A supercritical gasification device and method. The device comprises a supercritical gasification furnace (1.1), which comprises a heat exchange device (2.2) and a hearth (2.1) for gasification reaction of a material. The heat exchange device (2.2) is connected to the hearth (2.1). The heat exchange device (2.2) is provided with a material inlet (2.15) for the input of the material before gasification and a material outlet (2.16) for the outflow of the material after the gasification. The material inlet (2.15) of the heat exchange device (2.2) is connected to the material outlet (2.16) by means of the hearth (2.1), and the material inlet (2.15) and the material outlet (2.16) are exposed out of the supercritical gasification furnace (1.1). The hearth (2.1) is provided with an oxygen nozzle (2.11) for oxidant input and a gas nozzle (2.12) for combustible gas input. A lighter device for ignition is provided between the ports of the oxygen and gas nozzles in the hearth (2.1). Integrating a preheating system, a supercritical water medium heating system, and a gasification system facilitates taking effective heat insulation measures, thereby achieving a more energy-saving effect, and easily achieving the most sufficient implementation conditions required for supercritical gasification.

Description

Supercritical gasification device and method

Technical field

The invention relates to a gasification device and method, in particular to a supercritical gasification device and method.

Background technique

Material gasification is an important method involving people's life and production worldwide, especially in the energy field. Due to the large population growth and rapid economic development, the energy industry based on coal and oil has brought immeasurable negative effects on the global environment. , Which is mainly manifested in that carbon is difficult to obtain a virtuous cycle, which leads to global warming, which leads to frequent natural disasters. At the same time, the pollution of the natural environment on which people depend is worsening. Therefore, the clean use of coal and the acquisition of clean energy to replace petroleum are A major issue that humanity needs to solve urgently. There are many methods for gasification of coal and agricultural and forestry wastes in industrial production, but the method of gasification in supercritical water environment is rare. The present invention is to provide a solution that can completely solve the problem in the field of energy and environmental protection. Ways to perplex all mankind’s problems.

Supercritical water refers to water when the water is in a high temperature and high pressure state at its critical point (374.3°C, 22.05MPa), and the density of water expanded due to high temperature is exactly the same as the density of water vapor compressed due to high pressure. At this time, there is no difference between the liquid and gas of water, and they completely blend together to present a new high-temperature and high-pressure liquid, called Supercritical Water (SCW). Under this condition, water has many unique properties. : It has good mass and heat transfer properties. These characteristics make supercritical water an excellent reaction medium. Non-polar organics such as hydrocarbons and polar organics are completely miscible with supercritical water. Oxygen, nitrogen, carbon monoxide, carbon dioxide and other gases can also be in any proportion. Soluble in supercritical water, it can form a single-phase reaction. Usually within a few seconds of reaction time, a destruction rate of over 99.9% can be achieved. It can be used to treat difficult-to-decompose organic chlorides, sludge, dioxins in fly ash, and other dangerous organic substances. Inorganic substances, especially salts, have very low solubility in supercritical water, and can be separated almost insoluble, and become a general fluid aqueous solution after returning to normal temperature and pressure, so there is no concern about secondary pollution.

Supercritical Water Oxidation (Supercritical Water Oxidation for short SCWO) method is a technology with extremely clean treatment efficiency and does not require post-treatment equipment. In addition, when the organic content exceeds 2%, the SCWO process can form self-heating without additional heat supply. These characteristics make SCWO have its unique advantages compared with traditional wastewater treatment technologies such as biochemical treatment, Wet Air Oxidation (WAO), and combustion. For wastewater systems that are difficult to treat by traditional methods, SCWO has become A new environmental protection technology with great potential advantages. The supercritical water oxidation method was first proposed by American scholar Modell and others in the mid-1980s and has been unable to enter the market for more than 30 years. The main reason is that the previous SCWO technology reaction system includes: feed system, pump, preheater , Reactor, cooler (or heat recovery system), separator, etc. The connection between the material preheating system, the supercritical water medium heating system, the oxidant preheating system and the reactor is too complicated, and the equipment material requirements are very high. Not only the equipment construction and production and operation costs are high, but also the entire The system is very unreliable.

Therefore, there is an urgent need for a new gasification principle that can easily achieve the most sufficient realization conditions required by the SCWO method (temperature>374.3℃; pressure>22.05MPa) and at the same time meet the new gasification principle of coal and other materials to complete heat absorption and reduction to hydrogen production in supercritical water Technical methods and devices.

Summary of the invention

The first technical problem to be solved by the present invention is to provide a supercritical gasification device with a simple and reasonable structure, convenient to achieve a supercritical state, high conversion efficiency and reasonable operating cost in view of the above-mentioned current state of the art.

The second technical problem to be solved by the present invention is to provide a supercritical gasification method with reasonable and practical technology, high efficiency and energy saving, which can effectively reduce operating costs.

The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a supercritical gasification device including a supercritical gasification furnace. It is characterized in that: the supercritical gasification furnace includes a heat exchange device and a furnace chamber for supplying materials for gasification reaction, the heat exchange device is connected with the furnace chamber, and the heat exchange device is provided with materials for the input of materials before gasification The material inlet of the heat exchange device is connected to the material outlet through the furnace, and the material inlet and the material outlet are both exposed outside the supercritical gasification furnace. The furnace is provided with an oxygen nozzle for the input of oxidant and a gas nozzle for the input of combustible gas, and an ignition device for ignition is arranged between the oxygen nozzle and the gas nozzle in the furnace.

In order to achieve the required residence time for the gasification reaction in a supercritical state, part of the feed heat exchange tube group of the heat exchange device is in the furnace, so that the furnace and the heat exchange device are integrated into one. In this way, the production process of material gasification from non-supercritical to supercritical state and then from supercritical to non-supercritical state is completed in the supercritical gasifier.

In order to facilitate the supply of oxygen and combustible gas into the furnace and enable the combustion reaction in the furnace, the material inlet and the material outlet are located on the same side of the heat exchange device, and the oxygen inlet and fuel gas inlet are located on the side away from the material inlet , And adjacent to the oxygen inlet is provided with an oxygen nozzle to facilitate the introduction of oxygen into the furnace, and adjacent to the fuel gas inlet is provided with a gas nozzle to facilitate the introduction of combustible gas into the furnace, and The fire device is arranged between the oxygen nozzle and the gas nozzle, so that it is convenient to realize the ignition in the furnace. Therefore, the existing external heating method is changed to directly spray combustible gas and pure oxygen into the furnace to start heating, and continue to input appropriate amount of oxygen during operation to maintain the temperature of the entire system. At the same time, the tube shape is adopted to better integrate heat preservation Measures to achieve better energy-saving effects; in addition, prepare for the follow-up furnace to reach and maintain a supercritical state.

In order to make the working pressure in the supercritical gasification device meet the supercritical requirements, the supercritical gasification furnace includes a first shell, and the furnace core composed of the hearth and the heat exchange device is located in the first shell. The shell is provided with a nitrogen inlet for nitrogen input and a nitrogen outlet for nitrogen outflow, and both the material inlet and the material outlet are exposed outside the first shell. The first shell usually adopts a high-pressure-resistant protective shell structure to better meet the pressure requirements of the supercritical gasification reaction. At the same time, the materials, motors and gearboxes in the supercritical gasification furnace are all in In a nearly equal pressure environment with dry pure nitrogen, it is like working under normal pressure, which solves the safety sealing problem caused by the huge pressure difference of the equipment made of multiple parts.

Further, a pressure sensor is provided in the first housing, a signal output end of the pressure sensor is connected to a pressure signal input end of an automated control system, and a signal output end of the automated control system is connected to a nitrogen supply system.

The furnace is provided with a pressure sensor for testing its internal pressure and a temperature sensor for testing its internal temperature. The signal output terminals of the temperature sensor and the pressure sensor are connected to the corresponding signal input terminals of the automation control system. The signal output terminal of the automation control system is connected with the oxidant supply system, and the signal output terminal of the automation control system is also connected with the nitrogen supply system. In this way, the signal is transmitted to the automatic control system through the pressure sensor during operation, and the automatic control system controls the nitrogen supply system to input dry pure nitrogen into the supercritical gasification furnace, so that the nitrogen pressure in the supercritical gasification furnace is consistent with the supercritical gas The pressure in the furnace is kept equal, and the error is less than 0.5MPa; in addition, the signal of the temperature sensor is connected to the automatic control system, and the automatic control system controls the oxygen supply system to spray an appropriate amount of oxygen into the furnace to maintain the furnace temperature. The temperature sensor signal of the material outlet is output to the automatic control system, and the automatic control system instructs the material feeding system to control the feed flow rate to control the temperature difference between the material inlet and outlet.

Further, a second shell is provided in the first shell as an insulation layer shell of the furnace and the heat exchange device to form the furnace core, the heat exchange device is partially located in the second shell, and the heat exchange device includes The feed tube group with the material inlet and the discharge tube group with the material outlet, the feed tube group and the discharge tube group are composed of heat exchange tubes with built-in spiral blades, the first shell and the second The space between the shells is provided with a motor for driving the spiral blades to rotate. The power output end of the motor is transformed into a plurality of drive shafts through a variable speed gear box, and the drive shafts are connected with the spiral shafts of the corresponding spiral blades. The spiral blade is driven by the motor and the variable speed gear box to slowly rotate around its own spiral axis (for example, one rotation per minute) to clean the inner wall of the heat exchange tube, so that the material will not affect the heat exchange device during the reaction process. It causes blockage and at the same time, the material advances spirally in the heat exchange tube, which can not only make the particles have the effect of scouring and descaling on the heat exchange tube wall, but also has a better heat exchange effect.

In order to achieve high-efficiency heat exchange between adjacent feed heat exchange tubes and discharge heat exchange tubes, the heat exchange tubes in the feed heat exchange tube group are feed heat exchange tubes, and the heat exchange tubes in the discharge heat exchange tube group The heat exchange tube is a discharging heat exchange tube, the feeding heat exchange tube and the discharging heat exchange tube are arranged side by side at intervals, and a heat conducting layer is arranged between the adjacent feeding heat exchange tube and the discharging heat exchange tube , The arrangement of the heat conduction layer enables efficient heat exchange between adjacent feed heat exchange tubes and discharge heat exchange tubes.

The composition of the thermally conductive layer has various forms. Preferably, the thermally conductive layer includes at least one of silicon carbide, aluminum oxide, silicon dioxide, and at least one of pure metal copper, iron, and nickel. Thermally conductive medium.

In addition, the furnace core composed of the second shell and the furnace chamber and the heat exchange device is filled with insulation materials.

In order to realize the pressurization treatment of atmospheric materials while keeping the pressure of the subsequent materials entering the supercritical gasification furnace constant, the supercritical gasification device also includes a material feeding system useful for supplying materials into the supercritical gasification furnace. The material feeding system includes a buffer constant pressure material tank, a first material tank and a second material tank. The lower part of the first material tank can be communicated with the lower part of the second material tank through a pump. And the second material tank are provided with a first connection port communicating with the buffer constant pressure material tank and a second connection port for the input of normal pressure materials at positions adjacent to the upper part of the second material tank. The material output valve is connected to the material inlet, and the buffer constant pressure material tank is also provided with a gas constant pressure valve for maintaining a constant pressure of the material subsequently entering the furnace.

In order to realize that the first material tank and the second material tank supply 25MPa material into the buffer constant pressure material tank, the first material tank and the second material tank are respectively provided with a first sliding partition and a second Sliding partitions, the materials and clean water in the first material tank and the second material tank are separated by respective sliding partitions and arranged up and down.

The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a method for realizing supercritical gasification in the above-mentioned supercritical gasification device, which is characterized by including the following steps:

1) Start-up phase: by passing combustible gas and oxygen into the supercritical gasifier and igniting it, the combustible gas and oxygen are burned in the furnace to increase the temperature and the pressure at the same time, so that the furnace of the supercritical gasifier reaches Supercritical state

2) The atmospheric materials to be gasified are pressurized and then enter the heat exchange device in the supercritical gasifier for preheating, and the preheated materials enter the furnace of the supercritical gasifier for gasification reaction;

3) The gasified material in step 2) enters the gas-liquid separator through the material outlet of the supercritical gasifier for separation.

Specifically, in step 2), the normal pressure material is pressurized by the material feeding system and then buffered and constant pressure is performed by the buffer constant pressure material tank, and then enters the heat exchange device in the supercritical gasifier in step 1) for preheating .

In order to obtain the required material, in step 3), there are two gas-liquid separators, namely the first-stage gas-liquid separator and the second-stage gas-liquid separator. The gasified material enters the first stage through the material outlet. In the first-stage gas-liquid separator, the combustible gas separated by the first-stage gas-liquid separator is collected in a combustible gas storage tank for use; and the separated mixture of carbon dioxide, ash and water is decompressed or After the hydraulic turbine is decompressed, it enters the second-stage gas-liquid separator, the carbon dioxide gas separated by the second-stage gas-liquid separator is compressed to form liquid carbon dioxide, and the remaining mixed liquid separated by the second-stage gas-liquid separator is precipitated Afterwards, it is directly discharged or reused. In this way, it is easier to obtain the required fuel gas, liquid carbon dioxide, ash and clean water containing inorganic salts through various levels of gas-liquid separators.

In order to keep the pressure between the first shell and the second shell in the supercritical gasifier and the pressure in the furnace chamber at equal pressure, in step 1), the combustible gas and oxygen are burned in the furnace to increase the temperature and increase the pressure at the same time. It is necessary to input dry pure nitrogen into the supercritical gasification furnace, so that the nitrogen pressure between the first shell and the second shell in the critical gasification furnace is always equal to the pressure in the furnace, and the pressure error is less than 0.5MPa until When the temperature in the furnace reaches 600℃～1000℃ and the pressure reaches 23MPa～27MPa, the supercritical gasifier enters the normal operating state. The material stays in the furnace for 10 seconds to 300 seconds. The material before gasification is in the supercritical gas The difference T between the temperature at the material inlet of the chemical furnace and the temperature of the gasified material at the material outlet of the supercritical gasifier is 10°C-50°C.

Further, the material is a material slurry with a mass ratio of solid to liquid material of more than 40%.

In order to better carry out the supercritical gasification reaction, it is preferred in step 2): the temperature in the furnace is 800°C, the temperature in the furnace is maintained by controlling the amount of oxygen injected into the furnace, the furnace of the supercritical gasification furnace The internal operating pressure is 25MPa, the residence time of the material in the furnace is 60 seconds, and the temperature difference T before and after gasification of the material is 30°C.

Further preferably, the material contains 0-30% coal powder, 0-15% combustible waste powder or fine fragments, 50%-95% sewage and an appropriate amount of calcium carbonate powder to form a slurry.

Compared with the prior art, the present invention has the following advantages: 1. There is a heat exchange device and a hearth in the supercritical gasification furnace, so that the preheating system, supercritical water medium heating system and gasification in the supercritical gasification furnace The system can be integrated to take effective heat preservation measures and be more energy-saving. Its conversion efficiency is high, and the operation cost is reasonable, and it is easy to achieve the most sufficient realization conditions required for supercritical gasification (temperature>400℃; pressure>22.1MPa ); 2. The heat exchange tube with built-in spiral blades is used in the heat exchange device to achieve more efficient heat exchange and effectively solve the problem of fouling and blockage in the heat exchange tube.

In addition, the integration of the device of the present invention greatly simplifies the process route, greatly reduces the construction and operating costs of the supercritical gasification device, greatly improves the production efficiency, and the operation of the entire system becomes extremely stable and reliable, because of the material feeding of the present invention. The system can crush coal, agricultural and forestry wastes, domestic garbage and even floating organic wastes in rivers, lakes and seas into particles or small fragments and mix them with organic toxic waste water to form a slurry, which can easily enter the supercritical heat exchange device for gasification , So as to realize the energy conversion and the efficient production process of harmless thermal decomposition of organic toxic substances.

Description of the drawings

Figure 1 is a schematic diagram of a supercritical gasification device and method according to an embodiment of the present invention;

Figure 2 is a schematic diagram of the structure of the supercritical gasifier in Figure 1;

Fig. 3 is a schematic diagram of the structure of the material feeding system in Fig. 1.

detailed description

The present invention will be further described in detail below in conjunction with the embodiments of the drawings.

As shown in Figure 1, the supercritical gasification device includes supercritical gasification furnace 1.1, material feeding system 1.2, oxidant supply system 1.3, nitrogen supply system 1.4, gas-liquid separator, carbon dioxide liquefaction system 1.64, ash and slag water precipitation Separation tank 1.63 and automatic control system 1.7.

The material feed system 1.2 is connected to the supercritical gasification furnace 1.1 through the constant pressure material output valve 1.21, and the oxidant supply system 1.3 is connected to the supercritical gasification furnace 1.1 through the buffer constant pressure oxygen tank output valve 1.31; in addition, gas-liquid separation There are two devices, namely the first-stage gas-liquid separator 1.5 and the second-stage gas-liquid separator 1.6; the supercritical gasifier 1.1 is connected to the nitrogen supply system 1.4 through the nitrogen output control valve 1.41, and the supercritical gas The chemical furnace 1.1 is connected to the first-stage gas-liquid separator 1.5. One end of the first-stage gas-liquid separator 1.5 is connected to the combustible gas storage tank 1.54 through the combustible gas output control valve 1.51. The other end of the first-stage gas-liquid separator 1.5 One end is connected to the second stage gas-liquid separator 1.6 through the first discharge control valve 1.52 (or through the hydraulic turbine 1.53), and one port of the second stage gas-liquid separator 1.6 is connected to the carbon dioxide liquefaction system 1.64 through the carbon dioxide emission control valve 1.61 The other port of the second stage gas-liquid separator 1.6 is connected to the ash slag water sedimentation separation tank 1.63 through the second discharge control valve 1.62.

As shown in Figure 3, the aforementioned material feeding system 1.2 includes a first material tank 3.2a, a second material tank 3.2b, a pump 3.1, a clean water tank 3.3, and a buffer constant pressure material tank 3.5. among them:

The lower part of the first material tank 3.2a can be communicated with the lower part of the second material tank 3.2b through the pump 3.1. The first material tank 3.2a and the second material tank 3.2b are equipped with a buffer constant pressure material tank adjacent to the upper part. 3.5 The connected first connection port and the second connection port for the input of normal pressure materials, the buffer constant pressure material tank 3.5 is provided with a gas constant pressure valve 3.51 that is useful to keep the material entering the furnace 2.1 at a constant pressure. Constant pressure valve 3.51 is mainly a constant pressure valve that maintains a constant pressure of materials through combustible gas. Specifically, the buffer constant pressure material tank 3.5 communicates with the first material tank 3.2a through the first pressure limiting check valve 3.24, and the buffer constant pressure material tank 3.5 communicates with the second material tank 3.2b through the second pressure limiting check valve 3.25. When the first pressure limiting check valve 3.24 is opened, the material in the first material tank 3.2a can be input into the buffer constant pressure material tank 3.5. When the second pressure limiting check valve 3.25 is opened, the second The materials in the material tank 3.2b can be input into the buffer constant pressure material tank 3.5.

The first material tank 3.2a is provided with a first sliding partition 3.21a to separate clean water and materials; the second material tank 3.2b is filled with materials, and the second material tank 3.2b is also provided with a separate partition for clean water and materials The second sliding partition 3.21b; the first sliding partition 3.21a and the second sliding partition 3.21b can both move up and down, and the materials and clean water in the first material tank 3.2a and the second material tank 3.2b pass through each The sliding partitions are separated and arranged up and down.

Normal pressure materials are connected to the first material tank 3.2a through the first one-way valve 3.22, and normal pressure materials are connected to the second material tank 3.2b through the second one-way valve 3.23, that is, the first one-way Valve 3.22, normal pressure materials can be input into the first material tank 3.2a, open the second one-way valve 3.23, normal pressure materials can be input into the second material tank 3.2b.

The inlet of the clean water tank 3.3 is connected with a water inlet valve 3.32, and the lower outlet of the clean water tank 3.3 is communicated with the lower part of the second material tank 3.2b through a water supplement valve 3.31. The inlet of the pump 3.1 can be connected to the second material tank 3.2b through the fourth valve 3.14 and the clean water tank 3.3 through the make-up valve 3.31, and the output port of the pump 3.1 can be connected to the first material tank 3.2a through the second valve 3.12 The inlet of the pump 3.1 can be connected to the first material tank 3.2a through the third valve 3.13, and the output of the pump 3.1 is connected to the second material tank 3.2b through the first valve 3.11; specifically, the clean water tank 3.3 To make up water, connect the water make-up valve 3.31 through the lower outlet through the fourth valve 3.14 to the pump 3.1 and then the second valve 3.12 to the first material tank 3.2a.

The specific working process of the pump is as follows:

The pump 3.1 closes the fourth valve 3.14 and the second valve 3.12, opens the third valve 3.13 and the first valve 3.11, and presses the clean water in the first material tank 3.2a into the second material tank 3.2b; the pump 3.1 closes The first valve 3.11 and the third valve 3.13, the fourth valve 3.14 and the second valve 3.12 are opened, and the clean water in the second material tank 3.2b is pressed into the first material tank 3.2a.

The working process of the material feeding system is as follows:

When working, open the third valve 3.13, the first valve 3.11 and the pump 3.1. At this time, the material of about 0.2MPa enters the first material tank 3.2a through the first one-way valve 3.22, and the clean water part in the first material tank 3.2a The material in the second material tank 3.2b is pressed under the second sliding partition 3.21b of the second material tank 3.2b. Under the action of the clear water pressure under the second sliding partition 3.21b, the material in the second material tank 3.2b quickly reaches 25MPa. The second pressure limiting check valve 3.25 automatically opens, and the second material tank 3.21b inputs 25MPa material to the buffer constant pressure material tank 3.5.

When the second material tank 3.2b is almost filled with clean water and the first material tank 3.2a is almost filled with about 0.2MPa material, close the third valve 3.13 and the first valve 3.11, and then open the fourth valve 3.14 and the second Valve 3.12, at this time, the normal pressure material of about 0.2MPa enters the second material tank 3.2b through the second one-way valve 3.23, and the clean water is pressed into the first material tank 3.2a from the second material tank 3.2b via the pump 3.1 Below the first sliding partition 3.21a, the material in the first material tank 3.2a is pressed by the clear water under the sliding partition 3.21a, and the pressure quickly reaches 25MPa, and the first pressure limiting check valve 3.24 opens automatically. The material in the first material tank 3.2a is fed with 25MPa material to the buffer constant pressure material tank 3.5, so that the circulating operation can continuously input the 25MPa material into the supercritical gasifier through the buffer constant pressure material tank 3.5.

As shown in Figure 2, the above-mentioned supercritical gasification furnace 1.1 (that is, an integrated gasification and heat exchange reactor) includes a first shell 2.10, a second shell 2.7 located in the first shell 2.10, and part of it The heat exchange device 2.2 in the second shell 2.7, most of the heat exchange device 2.2 is located in the second shell 2.7, the above-mentioned first shell 2.10 is a high-pressure resistant shell, and the second shell 2.7 serves as the furnace 2.1 and heat exchange The insulation layer shell of the furnace core constituted by device 2.2, the supercritical gasification furnace 1.1 includes a heat exchange device 2.2 and a furnace 2.1 for material gasification reaction. The furnace 2.1 is connected with the heat exchange device 2.2, and the heat exchange device 2.2 is the feed material The heat exchange tube group 2.3 may be partly located in the furnace 2.1 to integrate the furnace 2.1 and the heat exchange device 2.2. Specifically, the heat exchange device 2.2 has a material inlet 2.15 for material input before gasification and a material after gasification. The outflowing material outlet 2.16, the material inlet 2.15 is connected to the material outlet 2.16 through the furnace 2.1, the material inlet 2.15 is connected with the material output valve 3.52 of the buffer constant pressure material tank 3.5, and the material outlet 2.16 is connected to the first stage gas-liquid separator 1.5 connection.

The first shell 2.10 is provided with a nitrogen inlet 2.17 for nitrogen input and a nitrogen outlet 2.18 for nitrogen outflow. Both the material inlet 2.15 and the material outlet 2.16 are exposed outside the first shell 2.10, and obviously also exposed in the furnace 2.1 and replacement The heating device 2.2 jointly constitutes outside the furnace core. A pressure sensor is arranged in the first housing 2.10, the signal output end of the pressure sensor is connected to the pressure signal input end of the automation control system 1.7, and the signal output end of the automation control system 1.7 is connected to the nitrogen supply system 1.4. The furnace 2.1 is equipped with a pressure sensor for testing its internal pressure and a temperature sensor for testing its internal temperature. The signal output terminals of the pressure sensor and temperature sensor in the furnace are connected to the corresponding signal input terminals of the automation control system 1.7, automation The signal output end of the control system 1.7 is connected to the oxidant supply system 1.3, and the signal output end of the automation control system 1.7 is connected to the nitrogen supply system 1.4.

A motor 2.9 and a transmission gear box 2.8 are arranged in the space between the inner peripheral wall of the first housing 2.10 and the outer peripheral wall of the second housing 2.7. The first housing 2.10 is a high-pressure resistant protective housing, and the second housing 2.7 An insulation layer 2.6 is set between the inner peripheral wall of the furnace 2.1 and most of the outer peripheral wall of the heat exchange device 2.2; the material inlet 2.15 and the material outlet 2.16 are located on the same side of the heat exchange device 2.2, on the other side of the furnace 2.1 away from the material inlet 2.15 An oxygen inlet 2.13 for oxidant input and a gas inlet 2.14 for flammable gas input are provided on the side. An oxygen nozzle 2.11 is provided adjacent to the oxygen inlet 2.13 to facilitate oxygen input into the furnace 2.1, and an adjacent gas inlet 2.14 is provided for convenient The combustible gas is input into the gas nozzle 2.12 in the furnace 2.1, and a ignition device for ignition is provided in the furnace. In this embodiment, the oxygen nozzle 2.11 and the gas nozzle 2.12 are provided between the ports in the furnace for ignition Lighter.

The heat exchange device 2.2 includes a feed heat exchange tube group 2.3 with a material inlet 2.15 and a discharge heat exchange tube group 2.4 with a material outlet 2.16. Both the feed heat exchange tube group and the discharge heat exchange tube group include a built-in spiral The blades are composed of heat exchange tubes. The space between the first shell 2.10 and the second shell 2.7 is provided with a motor 2.9 for driving the rotation of the spiral blade. The power output end of the motor 2.9 is changed into multiple drives through a variable speed gear box 2.8 The drive shaft is connected with the screw shaft of the corresponding screw blade. Specifically, the heat exchange tubes in the feed heat exchange tube group 2.3 are feed heat exchange tubes, the feed heat exchange tube group 2.3 includes a feed connection pipe 2.31 with a material inlet 2.15, and the feed heat exchange tube group 2.3 has The inlet end connected by the feeding connecting pipe 2.31; the heat exchange tube in the discharging heat exchange tube group 2.4 is the discharging heat exchange tube, and the discharging heat exchange tube group 2.4 includes the discharging connecting pipe 2.41 with the material outlet 2.16, The heat exchange tube group 2.4 has an outlet end connected to the discharge connecting pipe 2.41.

When there are multiple heat exchange tubes in the feed heat exchange tube group 2.3 and the discharge heat exchange tube group 2.4, the heat exchange tubes of the feed heat exchange tube group 2.3 and the discharge heat exchange tube 2.4 should be arranged side by side at intervals. Each feed heat exchange tube 2.3 has an inlet end connected to the feed connection pipe 2.31, the feed connection pipe 2.31 is connected to the material inlet 2.15, and the outlet end of each feed heat exchange tube 2.3 extends into the furnace 2.1 Inside and adjacent to the ports of the oxygen nozzle 2.11 and the gas nozzle 2.12. The material inlet 2.15 of the above-mentioned feeding heat exchange tube group and the material outlet 2.16 of the discharging heat exchange tube group are both located on the same side of the heat exchange device 2.2. In this embodiment, the discharging heat exchange tube and the feeding heat exchange tube are both There are two, but in practical applications, the number of the discharge heat exchange tube and the feed heat exchange tube is not limited to two.

In addition, the heat exchange tubes in the above-mentioned feed heat exchange tube group 2.3 and the discharge heat exchange tube group 2.4 are composed of heat exchange tubes with built-in spiral blades, and the spiral blades in each heat exchange tube pass through their respective spiral shafts. Connected to the power output of the motor 2.9. Specifically, the motor 2.9 is transformed into multiple drive shafts through the transmission gearbox 2.8, and the multiple drive shafts are respectively connected to the spiral shafts in the heat exchange tubes. The spiral blades in each heat exchange tube rotate around their respective spiral shafts under the drive of the motor 2.9. Thereby cleaning the inner tube wall of the heat exchange tube. The spiral leaf is made of pure nickel or pure iron, and the material is added with a proper amount of alkaline material (preferably calcium carbonate powder) to make it alkalescent, and when the material contains agricultural and forestry waste as the main feed into the system, it will naturally appear alkalescent , Pure metallic nickel and pure metallic iron have good corrosion resistance in alkaline state and reducing atmosphere, while pure metallic nickel has excellent oxidation and corrosion resistance, and pure metallic nickel is preferred.

In this embodiment, in order to achieve high-efficiency heat exchange between the adjacent feed heat exchange tube group 2.3 and the discharge heat exchange tube group 2.4, a heat transfer layer 2.5 is cast between adjacent heat exchange tubes. In addition, in the heat exchange device A thermally conductive layer 2.5 is also casted between the inner peripheral wall of the inner wall and the adjacent feed heat exchange tube or the adjacent discharge heat exchange tube. The medium of the above-mentioned thermal conductive layer 2.5 includes at least one of silicon carbide, aluminum oxide, silicon dioxide, and at least one of high-temperature-resistant pure metals such as copper, iron, nickel, etc. In an embodiment, the heat-conducting medium of the heat-conducting layer is preferably silicon carbide and pure metallic copper cast into a composite material with high thermal conductivity.

In this embodiment, the above-mentioned material is a slurry containing solids and liquid substances with a mass ratio of up to 40% or more. For example, the material contains a mass ratio of 0-30% coal powder and 0-15% combustible waste. The powder is mixed with 50%-95% sewage and an appropriate amount of calcium carbonate powder to form a slurry. The waste material powder can be agricultural and forestry waste material powder or fine fragments of organic waste such as domestic garbage. The material in this embodiment is made by mixing 30% coal powder, 10% agricultural and forestry waste powder, 60% sewage and appropriate amount of calcium carbonate powder. Slurry.

The working process of the above supercritical gasifier is as follows:

After the material passes through the constant pressure material output valve 1.21 in the high pressure feeding system (the constant pressure material output valve 1.21 is also the material output valve 3.52 in the material feeding system), it is input from the material inlet 2.15 through the feeding heat exchange tube group 2.3 To the furnace 2.1, and then from the furnace 2.1 to the first-stage gas-liquid separator 1.5 through the discharge heat exchange tube group 2.4 and the material outlet 2.16.

The working principle of the oxidant supply system only needs to be input from the liquid oxygen storage tank through the low temperature and high pressure liquid pump to the liquid oxygen expander. The automatic control system 1.7 can provide 25MPa oxygen to the furnace of the supercritical gasifier.

The working principle of the nitrogen supply system is similar to that of the oxidant (oxygen) supply system.

The supercritical gasification method is as follows:

Preparation procedure before starting: As shown in Figure 1, open the constant pressure material output valve 1.21, the first discharge control valve 1.52 and the second discharge control valve 1.62, and the material feeding system 1.2 will pass through the constant pressure material output valve 1.21 to start The supercritical gasification device inputs clean water (tap water), and the flow process of the clean water is: supercritical gasifier 1.1→first stage gas-liquid separator 1.5→first discharge control valve 1.52→water turbine 1.53→second stage gas-liquid Separator 1.6 → second discharge control valve 1.62. Among them, when the second discharge control valve 1.62 has clear water flowing out, the supercritical gasification device is full of clear water at this time, close the constant pressure material output valve 1.21; then open the gas through the gas inlet 2.14 from the gas nozzle 2.12 to the furnace 2.1 Enter the combustible gas (the combustible gas is a carbon monoxide hydrogen mixture or methane gas), and after the second emission control valve 1.62 has combustible gas flow out, the second emission control valve 1.62 is closed.

Step 1) The start-up procedure is also the start-up stage: first start the ignition device of the supercritical gasifier 1.1, so that the oxygen nozzle 2.11 and the gas nozzle 2.12 in the furnace continuously have high-voltage electric sparks between the ports in the furnace. Then open the buffer constant pressure oxygen tank output valve 1.31 and input pure oxygen from the oxygen nozzle 2.11 to the furnace 2.1 through the oxygen inlet 2.13. The furnace 2.1 is ignited, and the combustible gas and pure oxygen are continuously input. The pressure sensor, temperature sensor and automation The control system 1.7 controls the nitrogen input to make the entire supercritical gasification device slowly and synchronously heat up and increase the pressure, so that the supercritical gasification furnace reaches the supercritical state.

Step 2) Normal operation procedure: As shown in Figure 1, turn on the material feeding system 1.2, adjust it to reach the normal operating flow, and combine the materials (such as: 30% coal powder, 10% agricultural and forestry waste powder, 60% sewage and appropriate amount Calcium carbonate powder is mixed to form a slurry) After being pressurized, it is introduced into the heat exchange device 2.2 of the supercritical gasifier 1.1 for preheating. There are many ways to achieve pressurization. In this embodiment, the buffer constant pressure material tank 3.5 After being pressurized, it is introduced into the heat exchange device 2.2 of the supercritical gasifier 1.1 for preheating. The preheated material enters the furnace 2.1 of the supercritical gasifier 1.1; the gas constant pressure valve 3.51 is opened to ensure that it enters the furnace 2.1 To stabilize the material flow and pressure, adjust the oxidant supply system 1.3 so that oxygen enters the furnace 2.1 through the buffer constant pressure oxygen tank output valve 1.31 to the oxygen nozzle 2.11 to a proper flow rate, and then the furnace 2.1 maintains a working temperature of 800 through the automatic control system 1.7 ℃, the pressure is 25MPa, the carbon monoxide, hydrogen and a small amount of methane gas produced by the gasification reaction and a small amount of nitrogen generated by the reaction (it is gaseous under the environment of temperature <374.3℃ and pressure of 25MPa, and supercritical gasification The carbon dioxide produced by the furnace and a small amount of hydrogen sulfide may be mixed with water in a liquefied state) in the first stage gas-liquid separator 1.5 through the combustible gas output control valve 1.51 into the combustible gas storage tank 1.54 for later use, and The separated mixture of ash, water and liquid carbon dioxide passes through the first discharge control valve 1.52 to drive the turbine 1.53 and then enters the second stage gas-liquid separator 1.6. The carbon dioxide gas enters the carbon dioxide liquefaction system 1.64 through the carbon dioxide discharge control valve 1.61 to make liquid. Carbon dioxide, ash and slag water and a small amount of hydrogen sulfide (dissolved in ash and slag water) are discharged to the ash and slag water precipitation separation tank 1.63 through the second discharge control valve 1.62. In addition, the solid matter in the material can account for more than 40% by mass, which solves the problem that the existing high-pressure plunger sewage pump can only input the particle size ≤ 300 microns and the weight ratio of the particulate matter to water ≤ 3%.

In other words, the above gasified materials enter the first-stage gas-liquid separator 1.5 through the material outlet 2.16, and the combustible gas separated by the first-stage gas-liquid separator 1.5 is collected into the combustible gas storage tank 1.54 for use. , And the separated mixture of carbon dioxide, ash and water is decompressed or decompressed by a hydraulic turbine 1.53 (recovered pressure potential energy), and then enters the second-stage gas-liquid separator 1.6, and passes through the second-stage gas-liquid separator The separated carbon dioxide gas is compressed to form liquid carbon dioxide, and the inorganic salt-containing clean water after precipitation of the ash and water mixture separated by the second-stage gas-liquid separator can be directly discharged or reused. In this way, it is easier to obtain the required fuel gas, liquid carbon dioxide, ash and clean water containing inorganic salts through various levels of gas-liquid separators.

In the above, in the process of inputting combustible gas and oxygen to increase temperature and pressure, it is necessary to input dry pure nitrogen into the supercritical gasifier 1.1, so that the nitrogen pressure in the supercritical gasifier 1.1 is always the same as that in the furnace 2.1 The pressure is kept equal, and the pressure error is less than 0.5MPa, until the temperature in the furnace 2.1 reaches 600℃～1000℃ and the pressure reaches 23MPa～27MPa, the supercritical gasification furnace 1.1 enters the normal operation state, and the material stays in the furnace 2.1 for a time 10 seconds to 300 seconds, the difference between the temperature of the material before gasification at the material inlet 2.15 of the supercritical gasifier 1.1 and the temperature of the material after gasification at the material outlet 2.16 of the supercritical gasifier 1.1 The value T is 10°C to 50°C.

When the above-mentioned material feeding system 1.2 is turned on and adjusted to the normal operating flow rate, while the materials need to be input proportionally, the amount of oxygen entering the furnace 2.1 needs to be adjusted to reach the operating temperature and pressure parameters of the set operating state.

Recommended parameters in its running state:

Operating temperature in the furnace of the supercritical gasifier 1.1: 800℃;

Operating pressure in the furnace of the supercritical gasifier 1.1: 25MPa;

The residence time of the material in the furnace of the supercritical gasifier 1.1: 60 seconds;

The temperature difference T before and after the material gasification is 30°C.

When entering the normal operating state, the gasification furnace temperature is controlled by controlling the amount of oxygen injected into the furnace of the supercritical gasification furnace.

Finally, close the procedure: as shown in Figure 1, the running material feed system 1.2 is changed from material feed to clean water, and at the same time, the oxidant supply system 1.3 is closed for the oxygen flow into the supercritical gasifier, and the system quickly cools down. When the temperature of the supercritical gasifier 1.1 drops below 200°C, the material feeding system 1.2 is closed. During the whole process, the automatic control system 1.7 cooperates to control the nitrogen pressure for equalizing pressure reduction, so that the temperature and pressure of the entire system are reduced. Under pressure, all valves and equipment power supplies can be closed.

The above steps are precisely coordinated and implemented by the automated control system 1.7.

Claims

A supercritical gasification device, comprising a supercritical gasification furnace (1.1), characterized in that: the supercritical gasification furnace (1.1) includes a heat exchange device (2.2) and a furnace with materials for gasification reaction ( 2.1), the heat exchange device (2.2) is connected to the furnace (2.1), and the heat exchange device (2.2) has a material inlet (2.15) for the input of materials before gasification and a material outlet ( 2.16), the material inlet (2.15) of the heat exchange device (2.2) is connected to the material outlet (2.16) after passing through the furnace (2.1), and the material inlet (2.15) and the material outlet (2.16) are exposed to the outside In addition to the supercritical gasification furnace (1.1), the furnace (2.1) has an oxygen nozzle (2.11) for the input of oxidant and a gas nozzle (2.12) for the input of combustible gas, and inside the furnace (2.1) Set up a lighter to ignite.
The supercritical gasification device according to claim 1, characterized in that: the feed heat exchange tube group (2.3) of the heat exchange device (2.2) is partially in the hearth (2.1), so that the hearth (2.1) and The heat exchange device (2.2) is integrated.
The supercritical gasification device according to claim 1, characterized in that: the material inlet (2.15) and the material outlet (2.16) are located on the same side of the heat exchange device (2.2), and the oxygen inlet (2.13) and The gas inlets (2.14) are all located on the other side away from the material inlet (2.15), and an oxygen nozzle (2.11) is arranged adjacent to the oxygen inlet (2.13) to facilitate oxygen input into the furnace (2.1), A gas nozzle (2.12) is arranged adjacent to the gas inlet (2.14) to facilitate the input of combustible gas into the furnace (2.1), and an oxygen nozzle (2.11) in which the ignition device is arranged in the furnace (2.1) And the gas nozzle (2.12) between the ports in the furnace.
The supercritical gasification device according to any one of claims 1 to 3, characterized in that: the supercritical gasification furnace (1.1) comprises a first shell (2.10), and the furnace (2.1) The furnace core formed with the heat exchange device (2.2) is located in the first shell (2.10), and the first shell (2.10) is provided with a nitrogen inlet (2.17) for nitrogen input and a nitrogen outlet ( 2.18), both the material inlet (2.15) and the material outlet (2.16) are exposed outside the first shell (2.10).
The supercritical gasification device according to claim 4, characterized in that: the first housing (2.10) is provided with a pressure sensor, and the signal output end of the pressure sensor is connected with the pressure signal of the automatic control system (1.7) The input end is connected, the signal output end of the automatic control system (1.7) is connected to the nitrogen supply system (1.4); the furnace (2.1) is provided with a pressure sensor for testing its internal pressure and for testing its internal temperature The signal output terminal of the temperature sensor and the pressure sensor is connected to the corresponding signal input terminal of the automation control system (1.7), and the signal output terminal of the automation control system (1.7) is connected to the oxidant supply system (1.3) , The signal output end of the automatic control system (1.7) is also connected with the nitrogen supply system (1.4).
The supercritical gasification device according to claim 4, characterized in that: the first shell (2.10) is provided with a second shell (2.7) as a furnace (2.1) and a heat exchange device (2.2) to form a furnace The thermal insulation layer shell of the core, the heat exchange device (2.2) is partially located in the second shell (2.7), and the heat exchange device (2.2) includes a feed heat exchange tube group with a material inlet (2.15) and A discharge heat exchange tube group with a material outlet (2.16), the feed heat exchange tube group (2.3) and the discharge heat exchange tube group (2.4) are both composed of heat exchange tubes with built-in spiral blades, the A motor (2.9) is provided in the space between the first housing (2.10) and the second housing (2.7) to drive the rotation of the helical blades, and the power output end of the motor (2.9) passes through a variable speed gear box (2.8) It becomes a plurality of drive shafts, and the drive shafts are connected with the spiral shafts of the corresponding spiral blades.
The supercritical gasification device according to claim 6, characterized in that: the heat exchange tubes in the feed heat exchange tube group (2.3) are feed heat exchange tubes, and the discharge heat exchange tube group (2.4 The heat exchange tube in) is a discharging heat exchange tube, and the feeding heat exchange tube and the discharging heat exchange tube are arranged side by side at intervals, and are arranged between the adjacent feeding heat exchange tubes and the discharging heat exchange tubes Thermally conductive layer (2.5).
The supercritical gasification device according to claim 7, characterized in that: the thermally conductive layer (2.5) comprises at least one of silicon carbide, aluminum oxide, silicon dioxide, and pure metal copper, iron, and nickel. At least one heat transfer medium made by casting.
The supercritical gasification device according to claim 1, characterized in that it further comprises a material feeding system (1.2) for supplying materials to the supercritical gasification furnace (1.1), the material feeding system (1.2) ) Includes a buffer constant pressure material tank (3.5), a first material tank (3.2a) and a second material tank (3.2b). The lower part of the first material tank (3.2a) can communicate with the second material tank (3.2a) through a pump (3.1) The lower part of the material tank (3.2b) is connected, and the first material tank (3.2a) and the second material tank (3.2b) have a second material tank (3.5) connected to the buffer constant pressure material tank (3.5) at positions adjacent to the upper part. A connection port and a second connection port for the input of atmospheric materials, the buffer constant pressure material tank (3.5) has a material output valve (3.52) connected to the material inlet (2.15), and the buffer constant The pressure material tank (3.5) is also provided with a gas constant pressure valve (3.51) for maintaining a constant pressure of the material subsequently entering the furnace (2.1).
The supercritical gasification device according to claim 9, characterized in that: the first material tank (3.2a) and the second material tank (3.2b) are respectively provided with a first sliding partition ( 3.21a) and the second sliding partition (3.21b), the materials and water in the first material tank (3.2a) and the second material tank (3.2b) are separated by respective sliding partitions and arranged up and down .
A supercritical gasification method for a supercritical gasification device according to any one of claims 1 to 10, characterized by comprising the following steps:

1) Start-up stage: by passing combustible gas and oxygen into the supercritical gasifier (1.1) and igniting it, the combustible gas and oxygen are burned in the furnace to increase the temperature and pressure at the same time, so that the supercritical gasifier ( 1.1) A supercritical state is reached in the furnace (2.1);

2) The atmospheric materials that need to be gasified are pressurized and then enter the heat exchange device (2.2) in the supercritical gasifier (1.1) for preheating, and the preheated materials enter the supercritical gasifier (1.1) Gasification reaction in the furnace (2.1);

3) The gasified material in step 2) enters the gas-liquid separator through the material outlet of the supercritical gasifier for separation.
The supercritical gasification method according to claim 11, characterized in that: in step 2), the normal pressure material is pressurized by the material feeding system (1.2) and then buffered by the constant pressure material tank (3.5) for buffer constant pressure After step 1), it enters the heat exchange device (2.2) in the supercritical gasifier for preheating.
The supercritical gasification method according to claim 11, characterized in that: in step 2), there are two gas-liquid separators, namely the first-stage gas-liquid separator (1.5) and the second-stage gas-liquid separator The gasified material enters the first-stage gas-liquid separator (1.5) through the material outlet (2.16), and collects the combustible gas separated by the first-stage gas-liquid separator (1.5) into combustible gas In the storage tank (1.54) for use, the separated mixture of carbon dioxide, ash and water is decompressed or decompressed by a hydraulic turbine (1.53) and then enters the second stage gas-liquid separator (1.6). The carbon dioxide gas separated by the second-stage gas-liquid separator (1.6) is compressed to form liquid carbon dioxide, and the remaining ash and water mixture separated by the second-stage gas-liquid separator (1.6) is directly discharged or recycled after precipitation separation. use.
The supercritical gasification method according to claim 11, characterized in that: in step 2), during the process of combustible gas and oxygen burning in the furnace, heating up, and increasing the pressure, it is necessary to send to the supercritical gasification furnace (1.1) Input dry pure nitrogen to keep the nitrogen pressure in the supercritical gasification furnace (1.1) always equal to the pressure in the furnace (2.1), and the pressure error is less than 0.5MPa, until the temperature in the furnace (2.1) reaches 600℃ ～1000℃, the pressure inside the supercritical gasifier (1.1) reaches 23MPa～27MPa, and the supercritical gasifier (1.1) enters the normal operating state. The material stays in the furnace (2.1) for 10 seconds to 300 seconds. The difference between the temperature of the raw material at the material inlet (2.15) of the supercritical gasifier (1.1) and the temperature of the gasified material at the material outlet (2.16) of the supercritical gasifier (1.1) The value T is 10°C to 50°C.
The method of supercritical gasification according to claim 11, characterized in that: the material is a material slurry containing solids and liquid materials with a mass ratio of up to 40%.
The supercritical gasification method according to claim 14, characterized in that: in step 2), the temperature in the furnace (2.1) is 800°C, and the temperature in the furnace (2.1) is controlled by oxygen injection into the furnace (2.1) The internal volume is maintained. The operating pressure in the furnace of the supercritical gasifier (1.1) is 25MPa, the residence time of the material in the furnace (2.1) is 60 seconds, and the temperature difference T before and after the material gasification is 30°C.
The supercritical gasification method according to claim 15, characterized in that: the material contains a mass ratio of 0-30% coal powder, 0-15% combustible waste powder or fine fragments and 50%-95% % Sewage and an appropriate amount of calcium carbonate powder are mixed to form a slurry.