Method for reducing energy consumption of catalytic oxidation removal of CO and application thereof

Abstract

The application relates to the technical field of energy environment, and discloses a method for removing CO by catalytic oxidation and application thereof. The method is carried out in a catalytic oxidation system provided with a reaction unit, and comprises the following steps: under a first gas environment, introducing a tail gas to be treated, a noble metal honeycomb catalyst and methanol into the reaction unit to carry out a contact reaction, and obtaining treated gas with a CO content of less than or equal to 0.005 vol%; the first gas environment contains an oxygen-containing atmosphere, and optionally further contains a hydrogen-containing atmosphere. The catalytic oxidation system can remove CO tail gas generated under various working conditions, and has the advantages of simple operation, low energy consumption, no secondary pollution, high efficiency, good stability, being conducive to standard emission of CO and popularization of the CO removal technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy environment, in particular to a method for catalytic oxidation removal of CO and application thereof. BACKGROUND

[0002] At present, many processes in industrial production will produce gas rich in CO, such as coal gasification process, coke oven gas, blast furnace gas and converter gas in steel production process, etc. The CO concentration in these gases is relatively high (> 5 vol%), and direct emission will cause great resource waste and serious environmental pollution. For such gases, methods such as deep cooling separation, solvent recovery and solid adsorption separation are usually used for purification, separation and purification of CO. The CO content of the purified gas is very low and can be directly discharged up to standard.

[0003] However, there are some tail gases produced in the process with low CO concentration (< 5000 ppm), such as the resolved gas of low-temperature methanol washing device used in coal gasification device acid gas removal. For such tail gas, the recovery cost is high, in order to meet the emission requirements, adsorption, photocatalysis, low-temperature plasma conversion, combustion method and other ways are usually used to remove CO in the gas to meet the emission requirements. Catalytic oxidation method is introduced into high-efficiency catalyst on the basis of combustion method, which reduces the combustion process temperature, has the advantages of simple process and high removal efficiency, and thus attracts widespread attention.

[0004] However, the existing CO catalytic oxidation method still has great limitations in the use of CO tail gas removal method and device.

[0005] CN207478277U discloses a system for removing CO in flue gas, which sprays strong oxidizing agent into the flue by using a spraying device, and then the CO in the flue is oxidized into non-toxic and harmless CO2 and discharged from the flue. At the same time, the control unit controls the size of the regulating valve according to the concentration of CO in the flue, and then controls the input amount of the oxidizing agent, so as to ensure that the sprayed oxidizing agent can complete the conversion of CO in the flue into CO2 and discharge from the flue, so that the CO emission of the fluidized bed waste incinerator can meet the requirements of GB18485-2014 "Waste Incineration Pollution Control Standard", and the waste of oxidizing agent is also avoided, saving cost. However, this system is only suitable for the removal of CO in flue gas produced in the power system process. And the system has high energy consumption, and the treatment effect is general when the CO concentration in the flue gas is high.

[0006] CN107973271A discloses a reaction device for removing trace carbon monoxide from hydrogen-rich gas and a use method. By reasonably setting a material mixing tank, a raw material distribution port and a gas distribution pipe, the problem of uneven distribution of materials in the limited space of the reaction device for removing trace carbon monoxide from hydrogen-rich gas is solved, and the conversion utilization efficiency of the carbon monoxide removal catalyst is improved by avoiding hot spots. However, the method and device are mainly suitable for the removal of CO in hydrogen-rich gas (hydrogen content is 50-75 vol%).

[0007] Therefore, how to provide a CO catalytic oxidation technology capable of removing CO in tail gas generated in various working conditions, having low energy consumption, no secondary pollution, high efficiency and good stability is a core problem to be solved in the field at present. SUMMARY

[0008] The purpose of the present application is to overcome the problems of high energy consumption of the existing CO tail gas removal method and device, and the inability to meet the requirements of no secondary pollution and high removal rate while being applicable to tail gas generated in various working conditions.

[0009] To achieve the above-mentioned purpose, the first aspect of the present application provides a method for catalytic oxidation removal of CO, which is carried out in a catalytic oxidation system provided with a reaction unit, comprising:

[0010] In a first gas environment, the following steps are carried out: introducing the tail gas to be treated, a noble metal honeycomb catalyst and methanol into the reaction unit to carry out a contact reaction at 100-350℃, to obtain treated gas with CO content ≤0.005 vol%; the first gas environment contains an oxygen-containing atmosphere, and optionally also contains a hydrogen-containing atmosphere;

[0011] The CO content in the tail gas to be treated is 0.05-10 vol%, and the total content of dust particulate matter is not more than 2000 μg / cm 3 ; the particle size of the dust particulate matter is 20-100 μm;

[0012] The noble metal honeycomb catalyst contains a first active metal component, and the first active metal component is platinum and / or palladium; the content of the first active metal component, calculated as a metal element, is 0.5-10 wt% based on the total weight of the noble metal honeycomb catalyst;

[0013] The amount of the oxygen-containing atmosphere introduced is controlled so that the volume concentration ratio of O2 to CO in the system of the contact reaction at the initial moment of the contact reaction is 5-15:1; and the hydrogen content in the hydrogen-containing atmosphere is 0-5 vol% based on the total volume of hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the introduced methanol;

[0014] The amount of the methanol introduced is controlled so that the content of the methanol in the total volume of the hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the introduced methanol in the system of the contact reaction at the initial moment of the contact reaction is 0.05-0.5 vol%.

[0015] The second aspect of the present application provides the application of the method for catalytically oxidizing and removing CO in the field of energy environmental technology.

[0016] The catalytic oxidation system adopted by the present application can remove CO tail gas generated in various working conditions, has low energy consumption, no secondary pollution, high efficiency and good stability, is conducive to the standard discharge of CO and the promotion of CO removal technology. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a flowchart of a preferred method for catalytically oxidizing and removing CO provided by the present application. DETAILED DESCRIPTION

[0018] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values should be interpreted as approximately between the stated values. These ranges and values are understood to encompass any range or value that is near one or both of the stated values even though such ranges and / or values are not expressly disclosed. For values which are less than one, one should understand the value to be greater than zero.

[0019] As described previously, the first aspect of the present application provides a method for catalytically oxidizing and removing CO, which is carried out in a catalytic oxidation system provided with a reaction unit, comprising:

[0020] The tail gas to be treated, the noble metal honeycomb catalyst and the methanol are introduced into the reaction unit to carry out a contact reaction at 100-350℃ under a first gas environment to obtain a treated gas with a CO content of ≤0.005 vol%; the first gas environment contains an oxygen-containing atmosphere and optionally also contains a hydrogen-containing atmosphere;

[0021] The CO content in the tail gas to be treated is 0.05-10 vol%, and the total content of dust particulate matters is not more than 2000 μg / cm 3 ; the particle size of the dust particulate matters is 20-100 μm;

[0022] The noble metal honeycomb catalyst contains a first active metal component, and the first active metal component is platinum and / or palladium; the content of the first active metal component, calculated as metal elements, is 0.5-10 wt% based on the total weight of the noble metal honeycomb catalyst;

[0023] The amount of the oxygen-containing atmosphere introduced is controlled so that the ratio of the volume concentration of O2 to CO in the system of the contact reaction at the initial moment of the contact reaction is 5-15:1, and the hydrogen content in the hydrogen-containing atmosphere is 0-5 vol% based on the total volume of the hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the methanol introduced.

[0024] The amount of the methanol introduced is controlled so that the methanol content is 0.05-0.5 vol% based on the total volume of the hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the methanol introduced in the system of the contact reaction at the initial moment of the contact reaction.

[0025] Preferably, the hydrogen content is 0-1 vol% based on the total volume of the hydrogen in the hydrogen-containing atmosphere and the tail gas to be treated.

[0026] Preferably, the content of sulfides in the tail gas to be treated is 0-0.005 vol%.

[0027] More preferably, the content of sulfides in the tail gas to be treated is 0-0.002 vol%.

[0028] It should be noted that in the present application, the sulfides are carbonyl sulfide and hydrogen sulfide.

[0029] Preferably, the tail gas to be treated does not contain sulfides, and the CO content in the tail gas to be treated is less than 2 vol%, and the amount of the methanol introduced is controlled so that the methanol content is 0.1-0.2 vol% based on the total volume of the hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the methanol introduced in the system of the contact reaction at the initial moment of the contact reaction.

[0030] Preferably, the content of sulfides in the tail gas to be treated is 0.001-0.002 vol%, and the CO content in the tail gas to be treated is less than 2 vol%, and the amount of the methanol introduced is controlled so that the methanol content is 0.21-0.4 vol% based on the total volume of the hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the methanol introduced in the system of the contact reaction at the initial moment of the contact reaction.

[0031] Preferably, the content of sulfides in the tail gas to be treated is 0.001-0.002 vol%, and the CO content in the tail gas to be treated is ≥2 vol%, and the amount of the methanol introduced is controlled so that the methanol content is 0.05-0.09 vol% based on the total volume of the hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the methanol introduced in the system of the contact reaction at the initial moment of the contact reaction.

[0032] Preferably, the precious metal honeycomb catalyst further comprises a support and a carrier; the support is a monolithic honeycomb ceramic with cordierite material, and the carrier is at least one selected from alumina, silica, and zirconia; and

[0033] The content of the support is 44-95wt% based on the total weight of the precious metal honeycomb catalyst, and the content of the carrier is 5-30wt%.

[0034] Preferably, the precious metal honeycomb catalyst further comprises a second active metal component; the second active metal component is at least one selected from iron, cobalt, and nickel; and

[0035] The content of the second active metal component is 1-10wt% based on the total weight of the precious metal honeycomb catalyst in terms of metal elements.

[0036] It should be noted that the source of the preparation of the precious metal honeycomb catalyst is not particularly required in the present application, and it can be prepared by using conventional technical means in the art, or it can be obtained by commercial purchase, as long as the content of the support, carrier, first active metal component, and second active metal component meets the requirements.

[0037] According to a preferred embodiment, the oxygen-containing atmosphere is air.

[0038] It should be noted that the inventors have found that in the present application, when the content of hydrogen in the contact reaction system is not more than 1vol%, the scheme of the present application can still be realized.

[0039] According to a preferred embodiment, the content of hydrocarbon substances in the tail gas to be treated is 0-0.2vol%.

[0040] It should be noted that in the present application, the hydrocarbon substances are C 1-4 hydrocarbons.

[0041] Preferably, the relationship between the volume concentration of CO in the tail gas to be treated and the amount of the first active metal component in the precious metal honeycomb catalyst is 1-10:1, the volume concentration of CO is in mg / m 3 , and the amount of the first active metal component is in mg.

[0042] Preferably, the catalytic oxidation system further comprises a pretreatment unit, and the method further comprises: before the contact reaction of the tail gas to be treated, the tail gas to be treated is sequentially subjected to liquid removal and dust removal in the pretreatment unit to obtain pretreated gas I, and then the pretreated gas I is subjected to the contact reaction.

[0043] The conditions of the liquid removal and the dust removal are controlled so that the total content of the dust particles in the pretreated gas I is 0-20 μg / cm 3 .

[0044] Preferably, the pretreatment unit comprises a tail gas buffer tank and a tail gas filter connected in sequence, and the liquid removal and the dust removal are performed in the tail gas buffer tank and the tail gas filter respectively. The inventors have found that in this preferred case, the removal rate of the catalytic oxidation removal of CO is higher.

[0045] According to a preferred embodiment, at least one filter core is arranged in the tail gas filter.

[0046] According to a preferred embodiment, a liquid level meter is arranged on the side of the tail gas buffer tank, a drain valve is arranged on the bottom of the tail gas buffer tank, and a safety valve is arranged on the top of the tail gas buffer tank; wherein the liquid level meter is used to observe the liquid level in the tail gas buffer tank, when the liquid level in the buffer tank reaches more than 2 / 3, the liquid is removed through the drain valve; when the pressure in the buffer tank reaches more than 0.2 MPa, at least part of the tail gas to be treated is discharged between the outer cylinder and the inner cylinder of the inlet and outlet heat exchanger.

[0047] Preferably, a gas mixing unit is further arranged in the catalytic oxidation system, and the method further comprises: before the pretreated gas I and the oxygen-containing atmosphere are subjected to the contact reaction, the pretreated gas I and the oxygen-containing atmosphere are first introduced into the gas mixing unit to be mixed to obtain a mixed gas I, and then the mixed gas I is subjected to the contact reaction with the noble metal honeycomb catalyst and methanol.

[0048] Preferably, an inlet and outlet reaction heat exchanger is arranged in the gas mixing unit, and the inlet and outlet reaction heat exchanger comprises an inner cylinder and an outer cylinder; and

[0049] The mixing operation comprises: introducing the pretreated gas I and the oxygen-containing atmosphere into the inner cylinder of the inlet and outlet reaction heat exchanger to be mixed.

[0050] According to a preferred embodiment, the output range of the oxygen-containing atmosphere blower is 0-1000 m 3 / h, and a mass controller and an adjusting valve are arranged on the oxygen-containing atmosphere blower, which are used to adjust the output flow of the oxygen-containing atmosphere blower according to the CO content in the tail gas to be treated, so that in the system of the contact reaction at the initial moment of the contact reaction, the ratio of the concentration of O2 to the volume concentration of CO is 5-15:1. The inventors have found that in this preferred case, the removal effect of CO is the best, which can ensure that the CO concentration after the contact reaction is ≤0.005 vol%.

[0051] Preferably, the reaction unit is provided with an electric heater and a reaction furnace, and the method further comprises: before the mixed gas I is subjected to the contact reaction, the mixed gas I and the methanol are heated to 60-280℃ in the electric heater, and then introduced into the reaction furnace to be subjected to the contact reaction with the noble metal honeycomb catalyst and the methanol.

[0052] According to a preferred embodiment, the top of the reaction furnace is provided with a gas distributor.

[0053] Preferably, the measurement of the instantaneous temperature of the contact reaction is realized by arranging thermocouples at the upper, middle and lower parts of one side of the reaction furnace, and the thermocouples are inserted into the noble metal honeycomb catalyst through sleeves.

[0054] Preferably, the reaction furnace is provided with a temperature interlock, which is started when the temperature in the reaction furnace exceeds 450℃, to stop the introduction of the pretreated gas I and the oxygen-containing atmosphere into the reaction furnace.

[0055] Preferably, the temperature of the contact reaction is 240-310℃.

[0056] Preferably, the pressure of the contact reaction is 0.05-0.2 MPa.

[0057] Preferably, the method further comprises: heat exchange between at least part of the treated gas and the mixed gas I between the outer cylinder and the inner cylinder of the inlet-outlet reaction heat exchanger.

[0058] The inventors have found that in this preferred case, the heat utilization efficiency of the system can be improved, the energy consumption can be reduced, and the economy of the system can be improved.

[0059] According to a preferred embodiment, the method of the present application further comprises: flue gas analysis of the treated gas using a flue gas analyzer.

[0060] Preferably, when the CO concentration in the treated gas is lower than 0.005 vol%, the treated gas is subjected to high-point emission.

[0061] Preferably, before the tail gas to be treated is introduced into the tail gas buffer tank, it is passed through a pressure reducing valve to reduce the pressure to 0.05-0.2 MPa.

[0062] It should be noted that the protection level of the field instruments used in the selection of the instruments of the present application is at least IP65, and there is no requirement for the specific selection of various instruments, which can be defined according to the actual type.

[0063] The preferred specific embodiments of the method for catalytic oxidation removal of CO according to the present application will be described below. Figure 1 The preferred specific embodiments of the method for catalytic oxidation removal of CO according to the present application will be described below.

[0064] The method is performed in a catalytic oxidation system provided with a reaction unit;

[0065] (1) The tail gas to be treated is sequentially subjected to liquid removal and dust removal in a tail gas buffer tank and a tail gas filter respectively to obtain pretreated gas I;

[0066] (2) The pretreated gas I and the oxygen-containing atmosphere are introduced into the inner cylinder of the inlet-outlet reaction heat exchanger from a tail gas blower and an oxygen-containing atmosphere blower respectively to be mixed to obtain mixed gas I;

[0067] (3) Methanol is introduced into an electric heater from a methanol feeding system, heated to 60-280℃, and then introduced into a reaction furnace, and the mixed gas I is heated to 60-280℃ in the electric heater and then introduced into the reaction furnace through a gas distributor in the reaction furnace to contact with the noble metal honeycomb catalyst and the introduced methanol to obtain treated gas;

[0068] (4) The treated gas is subjected to CO concentration analysis using a flue gas analyzer, and when the CO concentration in the treated gas is lower than 0.005 vol%, the treated gas is subjected to heat exchange with the mixed gas I between the outer cylinder and the inner cylinder of the inlet-outlet reaction heat exchanger, and then the heat-exchanged treated gas is discharged at a high point.

[0069] Preferably, the reaction furnace is externally provided with a heat preservation device.

[0070] As described above, the second aspect of the present application provides an application of the method for catalytic oxidation removal of CO according to the first aspect in the field of energy environmental technology.

[0071] The present application will be described in detail below by way of examples, but the present application is not limited by any of the examples.

[0072] In the following examples, the chemical reagents used are all products of National Pharmaceutical Group Chemical Reagent Co., Ltd. unless otherwise specified.

[0073] In the following examples, the process flow shown in the following figure is used unless otherwise specified. Figure 1

[0074] Instrument selection: the protection level of the field instrument is IP65;

[0075] Thermocouple: armored Pt100 platinum thermistor in accordance with IEC751 standard, with a precision not lower than A level, spring compression type with reinforcing tube, 3-wire thermistor, fixed external thread connection; the on-site temperature indicating instrument selects a Ø100mm universal shockproof bimetallic thermometer with an external protective sleeve, with a precision level of 1.5;

[0076] ​Pressure instrument: remote pressure / differential pressure measurement selects intelligent pressure / differential pressure transmitter, the transmitter with digital meter, pressure transmitter with stainless steel two valve group, differential pressure transmitter with stainless steel three valve group, transmitter accuracy level ≤ ± 0.075%; on-site pressure instrument selects shockproof stainless steel spring tube pressure gauge with a dial diameter of 100mm, the accuracy is 1.5 level;

[0077] Quality controller: differential pressure transmitter for throttling device;

[0078] Liquid level meter: magnetic flip liquid level meter;

[0079] Regulating valve: the valve body is made of carbon steel, the valve core is made of stainless steel, and the valve pressure grade is not lower than the process pipeline pressure grade;

[0080] Flue gas analyzer: model Testo350, purchased from German instrument international trade (Shanghai) Co., Ltd.

[0081] Example 1

[0082] This example is used to illustrate the method for catalytic oxidation removal of CO provided by the application, which is carried out in a catalytic oxidation system provided with a reaction unit according to the parameters in table 2, and the first gas environment does not contain a hydrogen-containing atmosphere, specifically;

[0083] (1) the treated tail gas is passed through a pressure reducing valve to reduce the pressure to 0.1 MPa, and then sequentially passes through a tail gas buffer tank and a tail gas filter provided with a filter core for liquid removal and dust removal, respectively, to obtain a pretreated gas I with a total content of dust particles of 20 μg / cm 3 ;

[0084] The composition of the treated tail gas is shown in table 1, and by observing the liquid level meter on the side of the buffer tank, when the buffer tank liquid level reaches 2 / 3, the liquid is removed through the emptying valve at the bottom of the buffer tank; when the pressure of the buffer tank reaches 0.2 MPa, a part of the treated tail gas is discharged between the outer cylinder and the inner cylinder of the inlet and outlet heat exchanger;

[0085] (2) the pretreated gas I and the oxygen-containing atmosphere (air) are introduced into the inner cylinder of the inlet and outlet reaction heat exchanger from the tail gas blower and the oxygen-containing atmosphere blower, respectively, to obtain a mixed gas I;

[0086] The mass controller and the regulating valve provided on the oxygen-containing atmosphere blower are used to control the introduction amount of the oxygen-containing atmosphere, so that the volume concentration ratio of O2 to CO in the system of the contact reaction at the initial moment of the contact reaction is 5:1;

[0087] (3) the methanol is introduced into the electric heater by the methanol feeding system, heated to 180℃, and then introduced into the reaction furnace, and the mixed gas I is heated to 180℃ in the electric heater and then introduced into the reaction furnace through the gas distributor in the reaction furnace; wherein the amount of methanol introduced is controlled so that the content of methanol in the system of the contact reaction at the initial moment of the contact reaction is 0.15 vol% based on the total volume of the tail gas to be treated and the introduced methanol, and the contact reaction is carried out in the reaction furnace under the conditions of 240℃ and 0.1 MPa with the noble metal honeycomb catalyst and the introduced methanol, to obtain treated gas, the CO concentration of the treated gas is analyzed by using a flue gas analyzer, the CO content is 0.002 vol%, which meets the enterprise standard of less than 0.01 vol%, the treated gas is heat exchanged with the mixed gas I between the outer cylinder and the inner cylinder of the inlet and outlet reaction heat exchanger, and then the heat-exchanged treated gas is discharged at a high point;

[0088] Wherein, the measurement of the instantaneous temperature of the contact reaction is realized by arranging thermocouples at the upper, middle and lower parts of one side of the reaction furnace, and the thermocouples are inserted into the noble metal honeycomb catalyst through sleeves; when the temperature in the reaction furnace exceeds 450℃, the temperature interlock on the reaction furnace is started, and the introduction of the pretreated gas I and the oxygen-containing atmosphere into the reaction furnace is stopped;

[0089] The noble metal honeycomb catalyst is a platinum-alumina catalyst, wherein the support body is a monolithic honeycomb ceramic with cordierite material, the carrier is alumina, the second active metal component is iron, and the first active metal component is platinum; and based on the total weight of the noble metal honeycomb catalyst, the content of the support body is 70 wt%, the content of the carrier is 25 wt%, the content of the second active metal component is 2 wt% in terms of metal elements, and the content of the first active metal component is 1 wt%;

[0090] The relationship between the volume concentration of CO in the tail gas to be treated and the amount of the first active metal component in the noble metal honeycomb catalyst is 1:1;

[0091] The CO content in the finally obtained treated gas is 0.002 vol%, which meets the enterprise standard of less than 0.01 vol%.

[0092] Example 2

[0093] This example was carried out by using the similar method of Example 1, except that the composition of the tail gas to be treated was changed, and the noble metal honeycomb catalyst was a palladium-alumina catalyst, wherein the support was a monolithic honeycomb ceramic with the material of cordierite, the carrier was alumina, the second active metal component was iron, and the first active metal component was palladium; and based on the total weight of the noble metal honeycomb catalyst, the content of the support was 68 wt%, the content of the carrier was 25 wt%, the content of the second active metal component was 2 wt% in terms of metal elements, and the content of the first active metal component was 1 wt%;

[0094] The amount of methanol introduced was controlled so that the content of methanol in the system of the contact reaction at the initial moment of the contact reaction was 0.3 vol% based on the total volume of the tail gas to be treated and the introduced methanol.

[0095] And the methanol was introduced into the electric heater by the methanol feeding system and heated to 240°C, then introduced into the reaction furnace, and the mixed gas I was heated to 240°C in the electric heater and then introduced into the reaction furnace through the gas distributor in the reaction furnace, and the contact reaction was at 300°C, and the specific parameters were shown in Table 2; finally, the CO content in the treated gas was 0.002 vol%, which met the enterprise standard of less than 0.01 vol%.

[0096] Example 3

[0097] This example was carried out by using the similar method of Example 1, except that the composition of the tail gas to be treated was changed, and the noble metal honeycomb catalyst was a platinum-alumina catalyst, wherein the support was a monolithic honeycomb ceramic with the material of cordierite, the carrier was alumina, the second active metal component was cobalt, and the first active metal component was platinum; and based on the total weight of the noble metal honeycomb catalyst, the content of the support was 65 wt%, the content of the carrier was 25 wt%, the content of the second active metal component was 2 wt% in terms of metal elements, and the content of the first active metal component was 5 wt%;

[0098] The amount of methanol introduced was controlled so that the content of methanol in the system of the contact reaction at the initial moment of the contact reaction was 0.07 vol% based on the total volume of the tail gas to be treated and the introduced methanol.

[0099] And the methanol was introduced into the electric heater by the methanol feeding system and heated to 220°C, then introduced into the reaction furnace, and the mixed gas I was heated to 220°C in the electric heater and then introduced into the reaction furnace through the gas distributor in the reaction furnace, and the contact reaction was at 280°C, and the specific parameters were shown in Table 2; finally, the CO content in the treated gas was 0.002 vol%, which met the enterprise standard of less than 0.01 vol%.

[0100] Example 4

[0101] This example was carried out by using the similar method of example 1, except that the composition of the tail gas to be treated was changed, and the parameters of the contact reaction conditions were different, see table 2 for the specific parameters;

[0102] The amount of methanol introduced was controlled so that the content of methanol in the system of the contact reaction at the initial moment was 0.4 vol% based on the total volume of the tail gas to be treated and the introduced methanol;

[0103] Wherein, the methanol was introduced into the electric heater heated to 240℃ by the methanol feeding system, then introduced into the reaction furnace, and the mixed gas I was heated to 240℃ in the electric heater, then introduced into the reaction furnace through the gas distributor in the reaction furnace, the contact reaction was 310℃, and finally the CO content in the treated gas was 0.004 vol%, which met the enterprise standard of less than 0.01 vol%.

[0104] Example 5

[0105] This example was carried out by using the similar method of example 1, except that the amount of the first active metal component in the noble metal honeycomb catalyst was different, and it met the relationship that the volume concentration of CO in the tail gas to be treated was 12 times the amount of the first active metal component in the noble metal honeycomb catalyst; finally the CO content in the treated gas was 0.009 vol%, which met the enterprise standard of less than 0.01 vol%.

[0106] Comparative example 1

[0107] This comparative example was carried out by using the similar method of example 1, except that the noble metal honeycomb catalyst was a silver-alumina catalyst, wherein the support was a monolithic honeycomb ceramic with cordierite material, the carrier was alumina, the second active metal component was iron, and the first active metal component was silver; and based on the total weight of the noble metal honeycomb catalyst, the content of the support was 70 wt%, the content of the carrier was 25 wt%, the content of the second active metal component was 2 wt% in terms of metal elements, and the content of the first active metal component was 1 wt%; finally the CO content in the treated gas was 0.1 vol%, which did not meet the enterprise standard of less than 0.01 vol%.

[0108] Comparative example 2

[0109] The comparative example is carried out by using the similar method of Example 1, except that the noble metal honeycomb catalyst is a platinum-alumina catalyst, wherein the support is a monolithic honeycomb ceramic with the material of cordierite, the carrier is alumina, the second active metal component is cobalt, and the first active metal component is platinum; and based on the total weight of the noble metal honeycomb catalyst, the content of the support is 72 wt%, the content of the carrier is 25 wt%, the content of the second active metal component is 2 wt% in terms of metal element, and the content of the first active metal component is 0.2 wt%; the CO content in the finally obtained treated gas is 0.2 vol%, which does not meet the enterprise standard of less than 0.01 vol%.

[0110] Comparative Example 3

[0111] The comparative example is carried out by using the similar method of Example 1, except that the volume concentration ratio of O2 to CO in the system of the contact reaction at the initial moment of the contact reaction is 4:1; the CO content in the finally obtained treated gas is 0.15 vol%, which does not meet the enterprise standard of less than 0.01 vol%.

[0112] Comparative Example 4

[0113] The comparative example is carried out by using the similar method of Example 1, except that in step (3), no methanol is introduced, that is, the mixed gas I is directly contacted with the noble metal honeycomb catalyst for the contact reaction, and the contact reaction temperature is 180°C; the CO content in the finally obtained treated gas is 0.009 vol%, which can meet the enterprise standard of less than 0.01 vol%.

[0114] Comparative Example 5

[0115] The comparative example is carried out by using the similar method of Example 1, except that the methanol is introduced into the electric heater to be heated to 240°C by the methanol feeding system, and then introduced into the reaction furnace, and the mixed gas I is heated to 240°C in the electric heater, and then introduced into the reaction furnace through the gas distributor in the reaction furnace for the contact reaction, and the contact reaction temperature is 240°C.

[0116] The finally obtained treated gas has the same CO content as that in Example 1, wherein the CO content is 0.002 vol%, which can meet the enterprise standard of less than 0.01 vol%, but the energy consumption is higher.

[0117] Comparative Example 6

[0118] The comparative example is carried out by using the similar method of Example 1, except that in step (3), the introduction amount of methanol is controlled, so that the content of methanol in the system of the contact reaction at the initial moment of the contact reaction is 0.6 vol% based on the total volume of the tail gas to be treated and the methanol;

[0119] Finally, the device has a problem of temperature rising, so that the temperature interlock of the device is started, and the device cannot normally remove CO gas.

[0120] Table 1

[0121]

[0122] Note: the sulfide is carbonyl sulfur and hydrogen sulfide;

[0123] The hydrocarbon is C 1-4 hydrocarbon;

[0124] The particle size of the dust particle is 20-100 mu m.

[0125] Table 2

[0126]

[0127] Note: the relationship between the amount of CO and the active metal is: the ratio of the volume concentration (mg / m 3 ) of CO to the amount of the first active metal component in the noble metal honeycomb catalyst (mg).

[0128] From the above results, it can be seen that the catalytic oxidation system can remove CO tail gas under various working conditions, especially can effectively remove CO from tail gas under non-hydrogen-rich working conditions. The method has good treatment effect, simple process and convenient operation, especially can reduce energy consumption, can reduce the external heat provided in the process of catalytic oxidation removal of CO, specifically, under the premise of the same treatment effect, the temperature of the methanol and mixed gas I heated by the electric heater can be reduced by at least 60 DEG C, and there is no secondary pollution, and has good application prospect.

[0129] The above describes the preferred embodiments of the present application, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all belong to the protection scope of the present application.

Claims

1. A method for catalytic oxidative removal of CO, characterized by, The method is carried out in a catalytic oxidation system provided with a reaction unit, comprising: under a first gas environment, introducing the tail gas to be treated, a noble metal honeycomb catalyst and methanol into the reaction unit to carry out a contact reaction at 100-350 DEG C, to obtain a treated gas with CO content ≤0.005 vol%; the first gas environment contains an oxygen-containing atmosphere, and optionally also contains a hydrogen-containing atmosphere; The CO content in the exhaust gas to be treated is 0.05-10 vol%, the total content of dust particles is not more than 2000 μg / cm 3 ; the particle size of the dust particles is 20-100 μm; the noble metal honeycomb catalyst contains a first active metal component, which is platinum and / or palladium; the content of the first active metal component is 0.5-10 wt% based on the total weight of the noble metal honeycomb catalyst; controlling the introduction amount of the oxygen-containing atmosphere, so that in the system of the contact reaction at the initial moment of the contact reaction, the volume concentration ratio of O2 to CO is 5-15:1; and based on the total volume of hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the introduced methanol, the hydrogen content is 0-5 vol%; controlling the introduction amount of the methanol, so that in the system of the contact reaction at the initial moment of the contact reaction, based on the total volume of hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the introduced methanol, the methanol content is 0.05-0.5 vol%.

2. The method of claim 1, wherein, based on the total volume of hydrogen in the hydrogen-containing atmosphere and the tail gas to be treated, the hydrogen content is 0-1 vol%.

3. The method of claim 1 or 2, wherein, the content of sulfide in the tail gas to be treated is 0-0.005 vol%.

4. The method of claim 1 or 2, wherein, the content of sulfide in the tail gas to be treated is 0-0.002 vol%.

5. The method of claim 3, wherein, the tail gas to be treated does not contain sulfide, and the CO content in the tail gas to be treated is less than 2 vol%, and the introduction amount of the methanol is controlled, so that in the system of the contact reaction at the initial moment of the contact reaction, based on the total volume of hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the introduced methanol, the methanol content is 0.1-0.2 vol%.

6. The method of claim 3, wherein, the content of sulfide in the tail gas to be treated is 0.001-0.002 vol%, and the CO content in the tail gas to be treated is less than 2 vol%, and the introduction amount of the methanol is controlled, so that in the system of the contact reaction at the initial moment of the contact reaction, based on the total volume of hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the introduced methanol, the methanol content is 0.21-0.4 vol%.

7. The method of claim 3, wherein, the content of sulfide in the tail gas to be treated is 0.001-0.002 vol%, and the CO content in the tail gas to be treated is ≥2 vol%, and the introduction amount of the methanol is controlled, so that in the system of the contact reaction at the initial moment of the contact reaction, based on the total volume of hydrogen in the hydrogen-containing atmosphere, the tail gas to be treated and the introduced methanol, the methanol content is 0.05-0.09 vol%.

8. The method of claim 1 or 2, wherein, The volume concentration of CO in the exhaust gas to be treated is in the range of 1-10:1 relative to the amount of the first active metal component in the precious metal honeycomb catalyst, the volume concentration of CO being measured in mg / m 3 and the amount of the first active metal component being measured in mg.

9. The method of claim 1 or 2, wherein, The catalytic oxidation system further comprises a pretreatment unit, and the method further comprises: sequentially performing liquid removal and dust removal on the tail gas to be treated in the pretreatment unit to obtain pretreated gas I before the tail gas to be treated is subjected to the contact reaction; and subjecting the pretreated gas I to the contact reaction. wherein the conditions of the liquid removal and dust removal are controlled so that the total content of the dust particulate matters in the pretreated gas I is 0 to 20 μg / cm 3 .

10. The method of claim 9, wherein, The pretreatment unit comprises a tail gas buffer tank and a tail gas filter connected in sequence, and the liquid removal and the dust removal are performed in the tail gas buffer tank and the tail gas filter, respectively.

11. The method of claim 10, wherein, The catalytic oxidation system further comprises a gas mixing unit, and the method further comprises: mixing the pretreated gas I and the oxygen-containing atmosphere in the gas mixing unit to obtain mixed gas I before the pretreated gas I and the oxygen-containing atmosphere are subjected to the contact reaction; and subjecting the mixed gas I to the contact reaction with the noble metal honeycomb catalyst and methanol.

12. The method of claim 11, wherein, The gas mixing unit is provided with an in-out reaction heat exchanger, and the in-out reaction heat exchanger comprises an inner cylinder and an outer cylinder. The operation of mixing comprises: introducing the pretreated gas I and the oxygen-containing atmosphere into the inner cylinder of the in-out reaction heat exchanger from a tail gas blower and an oxygen-containing atmosphere blower, respectively, to perform the mixing. The reaction unit is provided with an electric heater and a reaction furnace, and the method further comprises: heating the mixed gas I and the methanol in the electric heater to 60-280℃ before the mixed gas I is subjected to the contact reaction; and introducing the mixed gas I and the methanol into the reaction furnace to perform the contact reaction with the noble metal honeycomb catalyst and methanol.

13. The method of claim 11, wherein, The temperature of the contact reaction is 240-310℃; and / or 14. The method of claim 13, wherein, The pressure of the contact reaction is 0.05-0.2 MPa. The method further comprises: performing heat exchange between the outer cylinder and the inner cylinder of the in-out reaction heat exchanger with at least part of the treated gas, the tail gas to be treated and the oxygen-containing atmosphere.

15. The method of claim 12, wherein, 16. Use of the method for removing CO by catalytic oxidation according to any one of claims 1-15 in the field of energy and environmental technology. ​

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