Method for producing synthesis gas by non-catalytic partial oxidation in a corex melter gasifier

Abstract

The application provides a method for preparing synthesis gas by non-catalytic partial oxidation of a COREX smelting gasifier, and relates to the technical field of synthesis gas preparation. The method is to take the dome region of the COREX smelting gasifier as a reaction zone, take oxygen and natural gas as raw material gas, spray the raw material gas into the dome region by a burner on the dome of the COREX smelting gasifier, and perform non-catalytic partial oxidation reaction of methane to prepare synthesis gas mainly composed of hydrogen and carbon monoxide. The application adopts a technical scheme of non-catalytic partial oxidation of natural gas accompanied by reforming reaction of natural gas, water vapor and carbon dioxide, which does not exist in the prior art. By controlling the structure of the oxygen / natural gas burner and the circulating dust injection burner and the composition of the raw material gas, in combination with the high-temperature and high-pressure environment and high-speed airflow of the dome region, good kinetic conditions are provided for the non-catalytic partial oxidation reaction of natural gas, and the method is simple to operate, low in cost, high in efficiency, beneficial to industrial large-scale production and popularization and use.

Description

Technical Field

[0001] This invention relates to the technical field of syngas preparation, and more particularly to a method for preparing syngas using a COREX melt gasifier through non-catalytic partial oxidation. Background Technology

[0002] Natural gas is a clean energy source with promising applications, boasting the lowest carbon emissions per unit of calorific value among all fossil fuels. China's proven conventional natural gas reserves account for only 1.8% of the world's total, but its consumption is projected to maintain rapid growth for a long time. It is estimated that by 2030, natural gas will account for over 10% of primary energy consumption. Therefore, the efficient and rational utilization of natural gas resources will be a crucial breakthrough for reducing carbon emissions and mitigating the greenhouse effect in the coming decades.

[0003] Natural gas's main component is CH4. Currently, the main reactions for converting CH4 into syngas include steam reforming, carbon dioxide reforming, partial methane oxidation, and combinations thereof, accompanied by forward / reverse water-gas shift reactions. Steam reforming and carbon dioxide reforming are endothermic reactions, while partial methane oxidation is exothermic. Steam reforming and carbon dioxide reforming commonly use catalysts, which leads to the problem that carbon deposits generated during the reaction can easily deactivate the catalyst, requiring production interruption for catalyst replacement. The non-catalytic partial oxidation route, however, does not require a catalyst. The reaction can occur spontaneously under high temperature, high pressure, and specific feedstock ratios, effectively avoiding catalyst deactivation and reducing production costs while also offering advantages such as low energy consumption and high tolerance to feedstock impurities.

[0004] The drawback of non-catalytic partial oxidation is that the reaction process is at a high temperature, which places high demands on the high-temperature resistance of the reactor. It requires modification of the reactor structure, selection of reactor materials, and the use of a high-temperature heat recovery device to recover and utilize the sensible heat of the syngas.

[0005] Chinese patent CN113526465A discloses a method for producing syngas from natural gas through non-catalytic partial oxidation combined with carbon dioxide reforming. The method involves introducing a mixture of natural gas, oxygen, and carbon dioxide into a reaction channel via a perforated plate burner, where it is ignited at the burner. The reaction proceeds rapidly, and the product is stably output. The product flows out of the reactor outlet and is cooled and separated using water quenching to obtain syngas. This method clearly combines carbon dioxide reforming and methane partial oxidation. While it can synergistically convert carbon dioxide and methane, it suffers from low carbon dioxide conversion rates and requires structural modifications to the apparatus. The mixed gas has a very short residence time in the reaction zone, and the reactor space is limited, making it unsuitable for industrial production.

[0006] Chinese patent CN116621118A discloses a method for producing syngas through the non-catalytic partial oxidation of natural gas coupled with pulverized coal. This method requires an oxygen to methane volume ratio of 0.7-0.9:1, increasing the proportion of oxygen in the feed gas. It also requires adding pulverized coal via high-pressure inert gas and a precision burner designed and installed on the top of the furnace, resulting in high cost and low efficiency. The large amount of pulverized coal added necessitates precise control of the oxygen and carbon dioxide levels in the converter, which can trigger other side reactions, such as the adsorption reaction of methane by pulverized coal, leading to a low syngas conversion rate.

[0007] Chinese patent CN103896209A discloses a method for producing syngas from coal, natural gas and carbon dioxide through catalytic reforming. This technical solution requires improvements to the device structure and the participation of a catalyst. It suffers from technical defects in the traditional catalytic reforming process for producing syngas, including but not limited to catalyst deactivation and heat loss. Moreover, the coal raw material can introduce other impurities, affecting the syngas reforming process and composition, which is not conducive to the industrial utilization of syngas.

[0008] Chinese patent CN105272796A discloses a method for preparing acetylene using the non-catalytic partial oxidation of natural gas. The method involves preheating natural gas and then introducing it into an acetylene reactor, followed by the introduction of auxiliary oxygen for ignition. After successful ignition, oxygen is added for reaction, and the temperature is controlled to reach 570-600℃. The resulting cracked gas exits the acetylene reactor and sequentially enters a gas-liquid separator, a purification device, and downstream equipment. However, this method does not produce syngas through the non-catalytic partial oxidation of natural gas; the volume ratio of oxygen to natural gas is 1.79-1.89, which obviously consumes a large amount of oxygen and results in high costs. The relationship between the temperature of the reaction gas and the dust content further complicates the operation. Summary of the Invention

[0009] The technical problem this invention aims to solve is that current non-catalytic partial oxidation methods for preparing syngas mainly involve carbon dioxide reforming, methane partial oxidation, or a combination of both. These methods require specially prepared heat-resistant reactors and high-temperature heat recovery devices. The residence time of the mixed gas in the reaction zone is very short, the reactor space is small, and the reaction cannot achieve the desired industrial effect, which is not conducive to industrial production practice. Furthermore, some methods consume a large amount of oxygen and require coal or pulverized coal to participate in the reaction, which increases production costs and the impurity content in the syngas. They also affect the reforming process of the syngas, are difficult to operate, and have complex temperature control requirements.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0011] A method for preparing syngas by non-catalytic partial oxidation in a COREX melt gasifier, wherein the method uses the dome area of ​​the COREX melt gasifier as the reaction zone, and oxygen and natural gas as feed gas, which are injected into the dome area by burners in the dome of the COREX melt gasifier to carry out a non-catalytic partial oxidation reaction of methane, thereby preparing syngas with hydrogen and carbon monoxide as the main components.

[0012] Preferably, the COREX melting gasifier is a reactor in the COREX system that completes the melting and separation of sponge iron into molten iron and the production of reducing gas required for the reducing shaft furnace.

[0013] Preferably, the dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier, and the burners are 6 oxygen burners and 4 circulating dust injection burners, with 1-6 of the 6 oxygen burners modified to be oxygen / natural gas coaxial mixed injection burners.

[0014] Preferably, the volume ratio of oxygen to natural gas in the raw material gas is 0.5-0.8.

[0015] Preferably, the oxygen and natural gas need to be pressurized and preheated before being injected into the dome area.

[0016] Preferably, the pressure is increased to 350-400 kPa, and the preheating temperature is 25-250°C.

[0017] Preferably, the flow rates of oxygen and natural gas, the raw materials, introduced into the dome are 4000-8000 Nm³, respectively. 3 / h and 8000-10000Nm 3 / h.

[0018] Preferably, the reaction time for non-catalytic partial oxidation is 0.004-0.008 s.

[0019] Preferably, the average temperature of the dome region of the molten gasification furnace is 1020-1090℃.

[0020] Preferably, the syngas is discharged through the dome gas outlet, and the temperature of the syngas at the time of discharge is 1100°C. It enters the hot gas cyclone dust collector through the pipeline to remove unburned particles and dust. The syngas after dust removal can be fed into the COREX pre-reduction shaft furnace or processed and output as gas.

[0021] Preferably, in the method, the methane conversion rate is 99.2-100%, the carbon monoxide yield is 83.2-89.8%, the hydrogen yield is 60.4-65.8%, and the acetylene yield is 0.04-1.20%; the ratio of carbon monoxide and hydrogen in the resulting syngas will reach 95-98%, of which carbon monoxide accounts for about 45% and hydrogen accounts for 55%.

[0022] The principle of this invention:

[0023] The COREX molten gasifier is one of the main reactors in the COREX molten reduction ironmaking process. Based on the different chemical reactions and functions, the molten gasifier can be divided into four zones from top to bottom: (i) the dome free space; (ii) the coal-filled bed; (iii) the tuyeres swirl zone; and (iv) the hearth zone. The dome zone of the COREX molten gasifier is a free space with high temperature, high pressure, and relatively intense turbulent kinetic energy.

[0024] This invention fully utilizes the dome area of ​​the COREX molten gasifier and couples it with non-catalytic partial oxidation technology to produce syngas. On the one hand, it can provide high-quality reducing gas to meet the needs of iron-containing raw material reduction in the COREX pre-reduction shaft furnace, further improving the metallization rate of ore in the shaft furnace; on the other hand, it produces a large amount of low-cost, high-quality syngas for the production of coal chemical products such as methanol and ethylene glycol.

[0025] To meet the reaction requirements of non-catalytic partial oxidation and leverage its advantages, this invention introduces non-catalytic partial oxidation into the COREX melt reduction process, using the dome region of the COREX melt gasifier as the reaction zone. There are two reasons for this: First, the flame temperature of non-catalytic partial oxidation can reach 1800℃, while the tuyeres and dome of the melt gasifier can withstand temperatures exceeding 2000℃, thus the high-temperature resistance of the melt gasifier dome meets the requirements of non-catalytic partial oxidation. Second, the high-pressure environment and high-speed gas flow at the dome of the COREX melt gasifier provide favorable kinetic conditions for the non-catalytic partial oxidation of natural gas. Specifically, the non-catalytic partial oxidation of natural gas is a gas-phase reaction (1-1). The higher pressure within the reactor favors the forward reaction, and the high-speed gas flow allows for rapid mixing and complete reaction of natural gas and oxygen.

[0026]

[0027] The heat required for the non-catalytic partial oxidation reaction is partly provided by the heat carried by the rising gas in the lower semi-coke fixed bed of the COREX molten gasifier, and partly by the complete combustion reaction of a small portion of natural gas near the oxygen / natural gas coaxial mixed-injection burner area (1-2).

[0028]

[0029] During the non-catalytic partial oxidation of natural gas in the dome region, there are also reforming reactions of natural gas, water vapor and carbon dioxide (1-3)(1-4), with hydrogen and carbon monoxide as products.

[0030]

[0031]

[0032] The above technical solution has at least the following advantages compared with the existing technology:

[0033] The present invention proposes a method for producing syngas through non-catalytic partial oxidation in a COREX melt gasifier. This method can solve the technical problems in the prior art that are unfavorable to the non-catalytic partial oxidation of natural gas, such as reactor material and space, catalyst addition, and coal or pulverized coal addition, thereby improving the conversion rate of syngas.

[0034] This invention utilizes the dome region of a COREX molten gasifier to perform a non-catalytic partial oxidation reaction, which not only meets the high requirements of the reactor for heat resistance, but also allows for effective control of the reaction environment in the dome region. The control method is convenient and has the advantages of low cost and low pollution.

[0035] The dome area of ​​the COREX melting gasifier of this invention has a high-pressure environment and high-speed airflow. The reaction of the raw material gas is controlled by the oxygen / natural gas burners and the circulating dust injection burners to produce high-quality syngas and significantly improve the quality of the reducing gas produced by the COREX melting gasifier. This is beneficial to improving the reduction effect of the COREX pre-reduction vertical furnace and enhancing the quality of the pre-reduction product.

[0036] The synthesis gas prepared by the non-catalytic partial oxidation of the COREX melt gasifier of this invention has high industrial value and a wide range of applications. The synthesis gas has high yields of hydrogen and carbon monoxide and low heat energy consumption, making it suitable for industrial production practice.

[0037] In summary, compared with other traditional methods, the method of this invention adopts a reforming reaction technology solution for the non-catalytic partial oxidation of natural gas, which is not found in existing technologies, involving natural gas, water vapor, and carbon dioxide. By optimizing the structure of the oxygen / natural gas burner and the circulating dust injection burner, and controlling the composition of the feed gas, combined with the high-pressure environment and high-speed airflow in the dome area of ​​the COREX molten gasifier, it provides excellent kinetic conditions for the non-catalytic partial oxidation reaction of natural gas. The method is simple to operate, has low production costs, and high efficiency, making it suitable for large-scale industrial production and widespread use. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1This is a schematic diagram of the apparatus structure for a method of preparing syngas by non-catalytic partial oxidation in a COREX melt gasifier according to the present invention, wherein: 1 is the COREX melt gasifier, 2 is the hot coal gas cyclone dust collector, 31 is the natural gas pressure regulating valve, 32 is the oxygen pressure regulating valve, 41 is the natural gas preheater, 42 is the oxygen preheater, and 5 is the oxygen / natural gas coaxial mixed injection burner;

[0040] Figure 2 This is a schematic diagram of the burner distribution along the axial cross section of the furnace body in the apparatus structure of the non-catalytic partial oxidation method for preparing syngas in a COREX melt gasification furnace according to the present invention, after 1-6 of the 6 oxygen burners have been modified into oxygen / natural gas coaxial mixed injection burners. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] A method for preparing syngas by non-catalytic partial oxidation in a COREX melt gasifier, wherein the method uses the dome area of ​​the COREX melt gasifier as the reaction zone, and oxygen and natural gas as feed gas, which are injected into the dome area by burners in the dome of the COREX melt gasifier to carry out a non-catalytic partial oxidation reaction of methane, thereby preparing syngas with hydrogen and carbon monoxide as the main components.

[0043] Specifically, the COREX melting gasifier is a reactor in the COREX system that completes the melting and separation of sponge iron into molten iron and the production of reducing gas required for the reducing shaft furnace.

[0044] Specifically, the dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier, and the burners are 6 oxygen burners and 4 circulating dust injection burners. 1 to 6 of the 6 oxygen burners are modified to oxygen / natural gas coaxial mixed injection burners.

[0045] Specifically, the volume ratio of oxygen to natural gas in the feed gas is 0.5-0.8.

[0046] In particular, oxygen and natural gas need to be pressurized and preheated before being injected into the vault area.

[0047] Specifically, pressurize until the pressure reaches 350-400 kPa, and preheat the temperature to 25-250 °C.

[0048] Specifically, the flow rates of oxygen and natural gas, the raw materials, introduced into the dome are 4000-8000 Nm³, respectively. 3 / h and 8000-10000Nm 3 / h.

[0049] Specifically, the reaction time for non-catalytic partial oxidation is 0.004-0.008 s.

[0050] Specifically, the average temperature in the dome region of the molten gasifier is 1020-1090℃.

[0051] Specifically, the syngas is discharged through the dome gas outlet at a temperature of 1100°C. It then enters a hot gas cyclone dust collector through a pipeline to remove unburned particles and dust. The syngas after dust removal can be fed into the COREX pre-reduction shaft furnace or processed and output as gas.

[0052] Specifically, in the method, the methane conversion rate is 99.2-100%, the carbon monoxide yield is 83.2-89.8%, the hydrogen yield is 60.4-65.8%, and the acetylene yield is 0.04-1.20%; the ratio of carbon monoxide and hydrogen in the resulting syngas will reach 95-98%, of which carbon monoxide accounts for approximately 45% and hydrogen accounts for 55%.

[0053] Example 1

[0054] An apparatus for the non-catalytic partial oxidation of syngas using a COREX melt gasification furnace, comprising the main apparatus and components as follows: Figure 1 As shown, it includes a COREX molten gasification furnace 1, a hot gas cyclone dust collector 2, a natural gas pressure regulating valve 31, an oxygen pressure regulating valve 32, a natural gas preheater 41, an oxygen gas preheater 42, and an oxygen / natural gas coaxial mixed-injection burner 5. Figure 2 As shown, the dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier. The burners are 6 oxygen burners and 4 circulating dust injection burners. 6 of the 6 oxygen burners are modified into oxygen / natural gas coaxial mixed injection burners 5.

[0055] A method for producing syngas using a COREX melt gasifier through non-catalytic partial oxidation includes the following steps:

[0056] Step 1: Select natural gas and oxygen as raw materials, and introduce them into the natural gas pressure regulating valve 31 and oxygen pressure regulating valve 32 through the corresponding gas supply pipelines to increase the pressure to 350 kPa;

[0057] Step 2: The natural gas and oxygen after the pressure was increased in Step 1 are respectively introduced into the natural gas preheater 41 and the oxygen preheater 42 connected to the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32, and preheated to 180°C.

[0058] Step 3: The preheated natural gas and oxygen from Step 2 are transported to the COREX melting gasification furnace (part of the oxygen is used for blowing through the lower tuyeres of the furnace, such as...). Figure 1 (Illustrated), the oxygen / natural gas is mixed and injected into the dome area through the oxygen / natural gas coaxial mixing burner 5, wherein the volume ratio of oxygen to natural gas is 0.55, and the injection ratio of natural gas and oxygen can be effectively adjusted through the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32.

[0059] Step 4: In the dome area, oxygen and natural gas mix rapidly under the action of high-speed airflow. A small portion of the natural gas will undergo a complete combustion reaction with the oxygen, releasing a large amount of heat. The local ignition temperature can reach 1800-2300℃. At the same time, the rising furnace gas carries the heat generated by the combustion of coal in the lower semi-coke fixed bed into the dome area. Under the combined effect of the two, a high temperature of about 1020℃ will be generated in the dome area.

[0060] Step 5: The unreacted natural gas from Step 4 will continue to undergo a non-catalytic partial oxidation reaction with oxygen under high temperature and pressure to produce carbon monoxide and hydrogen syngas. After a period of reaction, carbon dioxide and water vapor in the gas phase will also undergo a reforming reaction with the natural gas in the dome, producing carbon monoxide and hydrogen. This will further increase the effective component ratio of the syngas.

[0061] Step Six: After the gas phase reaction in Step Five is complete, the high-temperature syngas at approximately 1100°C is discharged through the dome gas outlet and enters the hot gas cyclone dust collector through a pipeline to remove unburned particles and dust. The syngas after dust removal can be fed into the COREX pre-reduction vertical furnace or processed and output as gas.

[0062] In the method described in this embodiment, the methane conversion rate is 99.2-100%, the carbon monoxide yield is 83.2-89.8%, the hydrogen yield is 60.4-65.8%, the acetylene yield is 0.04-1.20%, and the synthesis gas contains approximately 45% carbon monoxide and approximately 55% hydrogen.

[0063] Example 2

[0064] An apparatus for the non-catalytic partial oxidation of syngas using a COREX melt gasification furnace, comprising the main apparatus and components as follows: Figure 1As shown, the system includes a COREX molten gasifier 1, a hot gas cyclone dust collector 2, a natural gas pressure regulating valve 31, an oxygen pressure regulating valve 32, a natural gas preheater 41, an oxygen gas preheater 42, and an oxygen / natural gas coaxial mixed-injection burner 5. The dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier. The burners consist of 6 oxygen burners and 4 circulating dust injection burners, with 5 of the 6 oxygen burners modified into oxygen / natural gas coaxial mixed-injection burners 5.

[0065] A method for producing syngas using a COREX melt gasifier through non-catalytic partial oxidation includes the following steps:

[0066] Step 1: Select natural gas and oxygen as raw materials, and introduce them into the natural gas pressure regulating valve 31 and oxygen pressure regulating valve 32 through the corresponding gas supply pipelines to increase the pressure to 360 kPa;

[0067] Step 2: The natural gas and oxygen after the pressure was increased in Step 1 are respectively introduced into the natural gas preheater 41 and the oxygen preheater 42 connected to the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32, and preheated to a temperature of 190℃.

[0068] Step 3: The preheated natural gas and oxygen from Step 2 are transported to the COREX melting gasification furnace (part of the oxygen is used for blowing through the lower tuyeres of the furnace, such as...). Figure 1 (Illustrated), the oxygen / natural gas is mixed and injected into the dome area through the oxygen / natural gas coaxial mixing burner 5, wherein the volume ratio of oxygen to natural gas is 0.60, and the injection ratio of natural gas and oxygen can be effectively adjusted through the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32;

[0069] Step 4: In the dome area, oxygen and natural gas mix rapidly under the action of high-speed airflow. A small portion of the natural gas will undergo a complete combustion reaction with the oxygen, releasing a large amount of heat. The local ignition temperature can reach 1800-2300℃. At the same time, the rising furnace gas carries the heat generated by the combustion of coal in the lower semi-coke fixed bed into the dome area. Under the combined effect of the two, a high temperature of about 1040℃ will be generated in the dome area.

[0070] Step 5: The unreacted natural gas from Step 4 will continue to undergo a non-catalytic partial oxidation reaction with oxygen under high temperature and pressure to produce carbon monoxide and hydrogen syngas. After a period of reaction, carbon dioxide and water vapor in the gas phase will also undergo a reforming reaction with the natural gas in the dome, producing carbon monoxide and hydrogen. This will further increase the effective component ratio of the syngas.

[0071] Step Six: After the gas phase reaction in Step Five is complete, the high-temperature syngas at approximately 1100°C is discharged through the dome gas outlet and enters the hot gas cyclone dust collector through a pipeline to remove unburned particles and dust. The syngas after dust removal can be fed into the COREX pre-reduction vertical furnace or processed and output as gas.

[0072] In the method described in this embodiment, the methane conversion rate is 99.2-100%, the carbon monoxide yield is 84.3-89.8%, the hydrogen yield is 61.3-65.8%, the acetylene yield is 0.23-1.20%, and the synthesis gas contains approximately 45% carbon monoxide and approximately 55% hydrogen.

[0073] Example 3

[0074] An apparatus for the non-catalytic partial oxidation of syngas using a COREX melt gasification furnace, comprising the main apparatus and components as follows: Figure 1 As shown, the system includes a COREX molten gasifier 1, a hot gas cyclone dust collector 2, a natural gas pressure regulating valve 31, an oxygen pressure regulating valve 32, a natural gas preheater 41, an oxygen gas preheater 42, and an oxygen / natural gas coaxial mixed-injection burner 5. The dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier. The burners consist of 6 oxygen burners and 4 circulating dust injection burners, with 4 of the 6 oxygen burners modified into oxygen / natural gas coaxial mixed-injection burners 5.

[0075] A method for producing syngas using a COREX melt gasifier through non-catalytic partial oxidation includes the following steps:

[0076] Step 1: Select natural gas and oxygen as raw materials, and introduce them into the natural gas pressure regulating valve 31 and oxygen pressure regulating valve 32 through the corresponding gas supply pipelines to increase the pressure to 370 kPa;

[0077] Step 2: The natural gas and oxygen after the pressure was increased in Step 1 are respectively introduced into the natural gas preheater 41 and the oxygen preheater 42 connected to the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32, and preheated to 200℃.

[0078] Step 3: The preheated natural gas and oxygen from Step 2 are transported to the COREX melting gasification furnace (part of the oxygen is used for blowing through the lower tuyeres of the furnace, such as...). Figure 1 (Illustrated), the oxygen / natural gas is mixed and injected into the dome area through the oxygen / natural gas coaxial mixing burner 5, wherein the volume ratio of oxygen to natural gas is 0.65, and the injection ratio of natural gas and oxygen can be effectively adjusted by the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32.

[0079] Step 4: In the dome area, oxygen and natural gas mix rapidly under the action of high-speed airflow. A small portion of the natural gas will undergo a complete combustion reaction with the oxygen, releasing a large amount of heat. The local ignition temperature can reach 1800-2300℃. At the same time, the rising furnace gas carries the heat generated by the combustion of coal in the lower semi-coke fixed bed into the dome area. Under the combined effect of the two, a high temperature of about 1060℃ will be generated in the dome area.

[0080] Step 5: The unreacted natural gas from Step 4 will continue to undergo a non-catalytic partial oxidation reaction with oxygen under high temperature and pressure to produce carbon monoxide and hydrogen syngas. After a period of reaction, carbon dioxide and water vapor in the gas phase will also undergo a reforming reaction with the natural gas in the dome, producing carbon monoxide and hydrogen. This will further increase the effective component ratio of the syngas.

[0081] Step Six: After the gas phase reaction in Step Five is complete, the high-temperature syngas at approximately 1100°C is discharged through the dome gas outlet and enters the hot gas cyclone dust collector through a pipeline to remove unburned particles and dust. The syngas after dust removal can be fed into the COREX pre-reduction vertical furnace or processed and output as gas.

[0082] In the method described in this embodiment, the methane conversion rate is 99.2-100%, the carbon monoxide yield is 85.4-89.8%, the hydrogen yield is 62.2-65.8%, the acetylene yield is 0.426-1.20%, and the synthesis gas contains approximately 45% carbon monoxide and approximately 55% hydrogen.

[0083] Example 4

[0084] An apparatus for the non-catalytic partial oxidation of syngas using a COREX melt gasification furnace, comprising the main apparatus and components as follows: Figure 1 As shown, the system includes a COREX molten gasifier 1, a hot gas cyclone dust collector 2, a natural gas pressure regulating valve 31, an oxygen pressure regulating valve 32, a natural gas preheater 41, an oxygen gas preheater 42, and an oxygen / natural gas coaxial mixed-injection burner 5. The dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier. The burners consist of 6 oxygen burners and 4 circulating dust injection burners, with 3 of the 6 oxygen burners modified into oxygen / natural gas coaxial mixed-injection burners 5.

[0085] A method for producing syngas using a COREX melt gasifier through non-catalytic partial oxidation includes the following steps:

[0086] Step 1: Select natural gas and oxygen as raw materials, and introduce them into the natural gas pressure regulating valve 31 and oxygen pressure regulating valve 32 through the corresponding gas supply pipelines to increase the pressure to 380 kPa;

[0087] Step 2: The natural gas and oxygen after the pressure was increased in Step 1 are respectively introduced into the natural gas preheater 41 and the oxygen preheater 42 connected to the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32, and preheated to a temperature of 210℃.

[0088] Step 3: The preheated natural gas and oxygen from Step 2 are transported to the COREX melting gasification furnace (part of the oxygen is used for blowing through the lower tuyeres of the furnace, such as...). Figure 1 (Illustrated), the oxygen / natural gas is mixed and injected into the dome area through the oxygen / natural gas coaxial mixing burner 5, wherein the volume ratio of oxygen to natural gas is 0.7, and the injection ratio of natural gas and oxygen can be effectively adjusted through the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32.

[0089] Step 4: In the dome area, oxygen and natural gas mix rapidly under the action of high-speed airflow. A small portion of the natural gas will undergo a complete combustion reaction with the oxygen, releasing a large amount of heat. The local ignition temperature can reach 1800-2300℃. At the same time, the rising furnace gas carries the heat generated by the combustion of coal in the lower semi-coke fixed bed into the dome area. Under the combined effect of the two, a high temperature of about 1070℃ will be generated in the dome area.

[0090] Step 5: The unreacted natural gas from Step 4 will continue to undergo a non-catalytic partial oxidation reaction with oxygen under high temperature and pressure to produce carbon monoxide and hydrogen syngas. After a period of reaction, carbon dioxide and water vapor in the gas phase will also undergo a reforming reaction with the natural gas in the dome, producing carbon monoxide and hydrogen. This will further increase the effective component ratio of the syngas.

[0091] Step Six: After the gas phase reaction in Step Five is complete, the high-temperature syngas at approximately 1100°C is discharged through the dome gas outlet and enters the hot gas cyclone dust collector through a pipeline to remove unburned particles and dust. The syngas after dust removal can be fed into the COREX pre-reduction vertical furnace or processed and output as gas.

[0092] In the method described in this embodiment, the methane conversion rate is 99.2-100%, the carbon monoxide yield is 86.5-89.8%, the hydrogen yield is 63.1-65.8%, the acetylene yield is 0.62-1.20%, and the syngas contains approximately 45% carbon monoxide and approximately 55% hydrogen.

[0093] Example 5

[0094] An apparatus for the non-catalytic partial oxidation of syngas using a COREX melt gasification furnace, comprising the main apparatus and components as follows: Figure 1As shown, the system includes a COREX molten gasifier 1, a hot gas cyclone dust collector 2, a natural gas pressure regulating valve 31, an oxygen pressure regulating valve 32, a natural gas preheater 41, an oxygen gas preheater 42, and an oxygen / natural gas coaxial mixed-injection burner 5. The dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier. The burners consist of 6 oxygen burners and 4 circulating dust injection burners, with 2 of the 6 oxygen burners modified into oxygen / natural gas coaxial mixed-injection burners 5.

[0095] A method for producing syngas using a COREX melt gasifier through non-catalytic partial oxidation includes the following steps:

[0096] Step 1: Select natural gas and oxygen as raw materials, and introduce them into the natural gas pressure regulating valve 31 and oxygen pressure regulating valve 32 through the corresponding gas supply pipelines to increase the pressure to 390 kPa;

[0097] Step 2: The natural gas and oxygen after the pressure was increased in Step 1 are respectively introduced into the natural gas preheater 41 and the oxygen preheater 42 connected to the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32, and preheated to a temperature of 230℃.

[0098] Step 3: The preheated natural gas and oxygen from Step 2 are transported to the COREX melting gasification furnace (part of the oxygen is used for blowing through the lower tuyeres of the furnace, such as...). Figure 1 (Illustrated), the oxygen / natural gas is mixed and injected into the dome area through the oxygen / natural gas coaxial mixing burner 5, wherein the volume ratio of oxygen to natural gas is 0.75, and the injection ratio of natural gas and oxygen can be effectively adjusted through the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32.

[0099] Step 4: In the dome area, oxygen and natural gas mix rapidly under the action of high-speed airflow. A small portion of the natural gas will undergo a complete combustion reaction with the oxygen, releasing a large amount of heat. The local ignition temperature can reach 1800-2300℃. At the same time, the rising furnace gas carries the heat generated by the combustion of coal in the lower semi-coke fixed bed into the dome area. Under the combined effect of the two, a high temperature of about 1080℃ will be generated in the dome area.

[0100] Step 5: The unreacted natural gas from Step 4 will continue to undergo a non-catalytic partial oxidation reaction with oxygen under high temperature and pressure to produce carbon monoxide and hydrogen syngas. After a period of reaction, carbon dioxide and water vapor in the gas phase will also undergo a reforming reaction with the natural gas in the dome, producing carbon monoxide and hydrogen. This will further increase the effective component ratio of the syngas.

[0101] Step Six: After the gas phase reaction in Step Five is complete, the high-temperature syngas at approximately 1100°C is discharged through the dome gas outlet and enters the hot gas cyclone dust collector through a pipeline to remove unburned particles and dust. The syngas after dust removal can be fed into the COREX pre-reduction vertical furnace or processed and output as gas.

[0102] In the method described in this embodiment, the methane conversion rate is 99.2-100%, the carbon monoxide yield is 87.6-89.8%, the hydrogen yield is 64.0-65.8%, the acetylene yield is 0.81-1.20%, and the syngas contains approximately 45% carbon monoxide and 55% hydrogen.

[0103] Example 6

[0104] An apparatus for the non-catalytic partial oxidation of syngas using a COREX melt gasification furnace, comprising the main apparatus and components as follows: Figure 1 As shown, the system includes a COREX molten gasifier 1, a hot gas cyclone dust collector 2, a natural gas pressure regulating valve 31, an oxygen pressure regulating valve 32, a natural gas preheater 41, an oxygen gas preheater 42, and an oxygen / natural gas coaxial mixed-injection burner 5. The dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier. The burners consist of 6 oxygen burners and 4 circulating dust injection burners, with one of the 6 oxygen burners modified into an oxygen / natural gas coaxial mixed-injection burner 5.

[0105] A method for producing syngas using a COREX melt gasifier through non-catalytic partial oxidation includes the following steps:

[0106] Step 1: Select natural gas and oxygen as raw materials, and introduce them into the natural gas pressure regulating valve 31 and oxygen pressure regulating valve 32 through the corresponding gas supply pipelines to increase the pressure to 400 kPa;

[0107] Step 2: The natural gas and oxygen after the pressure was increased in Step 1 are respectively introduced into the natural gas preheater 41 and the oxygen preheater 42 connected to the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32, and preheated to a temperature of 250℃.

[0108] Step 3: The preheated natural gas and oxygen from Step 2 are transported to the COREX melting gasification furnace (part of the oxygen is used for blowing through the lower tuyeres of the furnace, such as...). Figure 1 (Illustrated), the oxygen / natural gas is mixed and injected into the dome area through the oxygen / natural gas coaxial mixing burner 5, wherein the volume ratio of oxygen to natural gas is 0.8, and the injection ratio of natural gas and oxygen can be effectively adjusted through the natural gas pressure regulating valve 31 and the oxygen pressure regulating valve 32.

[0109] Step 4: In the dome area, oxygen and natural gas mix rapidly under the action of high-speed airflow. A small portion of the natural gas will undergo a complete combustion reaction with the oxygen, releasing a large amount of heat. The local ignition temperature can reach 1800-2300℃. At the same time, the rising furnace gas carries the heat generated by the combustion of coal in the lower semi-coke fixed bed into the dome area. Under the combined effect of the two, a high temperature of about 1090℃ will be generated in the dome area.

[0110] Step 5: The unreacted natural gas from Step 4 will continue to undergo a non-catalytic partial oxidation reaction with oxygen under high temperature and pressure to produce carbon monoxide and hydrogen syngas. After a period of reaction, carbon dioxide and water vapor in the gas phase will also undergo a reforming reaction with the natural gas in the dome, producing carbon monoxide and hydrogen. This will further increase the effective component ratio of the syngas.

[0111] Step Six: After the gas phase reaction in Step Five is complete, the high-temperature syngas at approximately 1100°C is discharged through the dome gas outlet and enters the hot gas cyclone dust collector through a pipeline to remove unburned particles and dust. The syngas after dust removal can be fed into the COREX pre-reduction vertical furnace or processed and output as gas.

[0112] In the method described in this embodiment, the methane conversion rate is 99.2-100%, the carbon monoxide yield is 88.7-89.8%, the hydrogen yield is 64.9-65.8%, the acetylene yield is 1-1.20%, and the syngas contains approximately 45% carbon monoxide and 55% hydrogen.

[0113] The present invention proposes a method for producing syngas through non-catalytic partial oxidation in a COREX melt gasifier. This method can solve the technical problems in the prior art that are unfavorable to the non-catalytic partial oxidation of natural gas, such as reactor material and space, catalyst addition, and coal or pulverized coal addition, thereby improving the conversion rate of syngas.

[0114] This invention utilizes the dome region of a COREX molten gasifier to perform a non-catalytic partial oxidation reaction, which not only meets the high requirements of the reactor for heat resistance, but also allows for effective control of the reaction environment in the dome region. The control method is convenient and has the advantages of low cost and low pollution.

[0115] The dome area of ​​the COREX melting gasifier of this invention has a high-pressure environment and high-speed airflow. The reaction of the raw material gas is controlled by the oxygen / natural gas burners and the circulating dust injection burners to produce high-quality syngas and significantly improve the quality of the reducing gas produced by the COREX melting gasifier. This is beneficial to improving the reduction effect of the COREX pre-reduction vertical furnace and enhancing the quality of the pre-reduction product.

[0116] The synthesis gas prepared by the non-catalytic partial oxidation of the COREX melt gasifier of this invention has high industrial value and a wide range of applications. The synthesis gas has high yields of hydrogen and carbon monoxide and low heat energy consumption, making it suitable for industrial production practice.

[0117] In summary, compared with other traditional methods, the method of this invention adopts a reforming reaction technology solution for the non-catalytic partial oxidation of natural gas, which is not found in existing technologies, involving natural gas, water vapor, and carbon dioxide. By optimizing the structure of the oxygen / natural gas burner and the circulating dust injection burner, and controlling the composition of the feed gas, combined with the high-pressure environment and high-speed airflow in the dome area of ​​the COREX molten gasifier, it provides excellent kinetic conditions for the non-catalytic partial oxidation reaction of natural gas. The method is simple to operate, has low production costs, and high efficiency, making it suitable for large-scale industrial production and widespread use.

[0118] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing syngas using a non-catalytic partial oxidation process in a COREX melt gasification furnace, characterized in that, The method uses the dome area of ​​the COREX melt gasifier as the reaction zone, and oxygen and natural gas as raw materials. The gas is injected into the dome area through burners in the dome of the COREX melt gasifier to carry out a non-catalytic partial oxidation reaction of methane. The average temperature of the dome area of ​​the melt gasifier is 1020-1090℃, and syngas with hydrogen and carbon monoxide as the main components is prepared. The dome area of ​​the COREX molten gasifier is the cavity above the semi-coke fixed bed in the molten gasifier. The burners are 6 oxygen burners and 4 circulating dust injection burners. 1-6 of the 6 oxygen burners are modified to oxygen / natural gas coaxial mixed injection burners. The volume ratio of oxygen to natural gas in the feed gas is 0.5-0.8; the flow rates of oxygen and natural gas introduced into the dome are 4000-8000 Nm³, respectively. 3 / h and 8000-10000Nm 3 / h; Oxygen and natural gas need to be pressurized and preheated before being injected into the vault area; Pressurize until the pressure reaches 350-400 kPa, and preheat the temperature to 25-250℃; The methane conversion rate is 99.2-100%, the carbon monoxide yield is 83.2-89.8%, the hydrogen yield is 60.4-65.8%, and the acetylene yield is 0.04-1.20%. The ratio of carbon monoxide and hydrogen in the resulting syngas will reach 95-98%, with carbon monoxide accounting for 45% and hydrogen accounting for 55%.

2. The method for preparing syngas using a non-catalytic partial oxidation process in a COREX melt gasification furnace according to claim 1, characterized in that, The COREX melting gasifier is a reactor in the COREX system that completes the melting and separation of sponge iron into molten iron and the production of reducing gas required for the reducing shaft furnace.

3. The method for preparing syngas using a non-catalytic partial oxidation process in a COREX melt gasification furnace according to claim 1, characterized in that, The reaction time for non-catalytic partial oxidation is 0.004-0.008 s.

Images