A deodorant adsorbent for kitchen waste, its preparation method and application

Abstract

The present invention discloses an odor removal adsorbent for kitchen waste, its preparation method and application. In this method, waste fluid catalytic cracking (FCC) catalysts are crushed, washed with water and dried to obtain FCC particles, which are then impregnated in a nickel nitrate solution and in-situ reduced to prepare Ni / FCC particle catalysts. The Ni / FCC particle catalysts are placed in a formaldehyde reforming hydrogen production reactor to grow carbon nanotubes, and then Ni / FCC-CNTs are obtained. Ni in the Ni / FCC-CNTs catalyst with grown carbon nanotubes is removed by using a perchloric acid solution to obtain FCC-CNTs. Finally, the FCC-CNTs are placed in an atmosphere furnace and treated with water vapor to finally obtain the odor removal adsorbent. This adsorbent is environmentally friendly, has high mechanical strength, large adsorption capacity, and the odor can be easily desorbed, and the adsorbent can be reused. This product can be widely applied to the field of kitchen waste disposal.

Description

Technical Field

[0001] The present invention relates to a deodorant adsorbent for kitchen waste, a preparation method thereof and an application thereof, and particularly relates to the field of reuse of waste FCC catalysts and the field of kitchen waste odor adsorbents. Background Art

[0002] Since the 21st century, with the rapid development of the economy, the demand for oil has been continuously increasing. Currently, China has become the second largest oil-consuming country in the world. With the strengthening of environmental protection concepts, the demand for light oil is also increasing. Fluid catalytic cracking (FCC) catalysts are widely used in modern petroleum refining industries due to their excellent activity, heavy metal resistance, activity stability, residue cracking performance, gasoline selectivity and low cost. During the catalytic process of petroleum refining, FCC catalysts will be deactivated under the combined action of sintering, contamination by heavy metals such as Ni, V, Fe, pulverization and hydrothermal effects.

[0003] At present, the main utilization ways of waste FCC catalysts can be divided into three categories: one is to use them as adsorbents to adsorb harmful substances and metal ions in wastewater; the second is to use them as adsorbents and incorporate them into clay to refine lubricating oil base oil and FCC diesel; the third is to replace part of the clay and use it as an adsorbent to refine paraffin. Of course, since the waste FCC catalyst contains about 3-8% rare earth (mainly La2O3 and CeO2), which is almost the same as the rare earth content in some ores. Therefore, there are also treatment measures to extract rare earth elements from waste FCC catalysts for recycling, which can not only bring huge economic benefits, but also save the exploitation of primary rare earth mineral resources. The most common technology for extracting rare earth elements from waste FCC catalysts is acid extraction technology, that is, using strong acid to dissolve the metal elements in the catalyst, and then separating and purifying. This method is simple to operate and has a high recovery rate. For example, patents CN111378842B, CN112695213B, CN111690811A, etc. all adopt acid extraction technology, and the recovery rate of rare earth elements can reach more than 95%. However, the use of acid extraction technology to extract rare earth elements from waste FCC catalysts does not fully utilize the value of waste FCC catalysts. FCC catalysts are a type of Y-type molecular sieve. Molecular sieves are not only good catalyst materials, but also excellent adsorbent materials due to their porous and large specific surface area characteristics. During the use of FCC catalysts, they are deactivated due to the deposition of coke and heavy metals on the catalyst surface and the collapse of some pores, but the overall structure of the catalyst is not damaged, and there is still value as an adsorbent.

[0004] On the other hand, food waste is the most common waste generated in daily life and belongs to domestic waste. Its main components include organic matter such as starchy food, plant fiber, animal protein and fat. It has the characteristics of high water content, high oil and salt content, easy to rot and stink, and inconvenient transportation. Food waste generated in special areas such as tourist scenic spots is very easy to harm the environmental quality during transportation and transfer. At present, the treatment technologies of food waste mainly include landfill, incineration, feed processing, anaerobic fermentation and aerobic fermentation. Among them, anaerobic fermentation and aerobic fermentation are more promising, but these two methods have a long treatment cycle and are difficult to meet the requirements of daily production and daily cleaning of food waste. Although the environmentally friendly food waste continuous treatment device (ZL201920806617.0) can achieve efficient degradation of food waste, obtain organic fertilizer, and meet the emission standards of waste gas, the bacteria will decompose organic matter and produce odor during its treatment process. In order to avoid the spread of odor during the disposal process, the research on deodorizing adsorbents is particularly important. Summary of the invention

[0005] The purpose of the present invention is to provide a deodorizing adsorbent for kitchen waste in view of the problems that the current disposal of kitchen waste produces odor and the recycling method of waste FCC catalyst is single and has low economic benefits; another purpose of the present invention is to provide a preparation method of the deodorizing adsorbent for kitchen waste.

[0006] The technical solution of the present invention is: although the waste FCC catalyst is deactivated due to heavy metals and carbon deposition, most of its pore structure is still intact, so it has excellent gas adsorption capacity; research has found that the carbon deposition on the surface of the waste FCC catalyst is usually multi-walled carbon nanotubes with high specific surface area, and carbon nanotubes also have excellent gas adsorption capacity, but the carbon deposition content is relatively low, so FCC particles are loaded with Ni to form Ni / FCC catalyst particles, so that they have formaldehyde reforming hydrogen production performance, and formaldehyde reforming hydrogen production process will produce by-products, that is, on the catalyst surface and in the microscopic pores Multi-walled carbon nanotubes are grown on the surface of the waste FCC catalyst, thereby further enhancing the adsorption capacity of the waste FCC catalyst. Because nickel is also a type of metal that is harmful to the human body, in order to avoid the presence of nickel in food waste, the nickel is removed by pickling with a perchloric acid solution after the Ni / FCC-CNTs are prepared. Finally, the number of hydroxyl groups on the surface of FCC-CNTs is increased through a high-temperature reaction with water vapor, so that the FCC-CNTs adsorbent has the advantages of high specific surface area and rich hydroxyl groups. The ability of hydroxyl groups to form hydrogen bonds with odor is used to increase the strength of odor adsorption, and the high specific surface area is used to increase the adsorption capacity of the adsorbent. In addition, when the adsorbent is saturated with odor adsorption, the adsorbent can be exposed to the sun to remove the adsorbed odor, thereby achieving the effect of recycling.

[0007] A preparation method of a deodorant adsorbent for kitchen waste, and the steps of the preparation method are as follows:

[0008] (1) Pretreatment of waste FCC catalyst

[0009] Ball-mill and crush the waste FCC catalyst, screen out waste FCC catalyst particles with a mesh size of 20 - 40, wash and then dry for standby;

[0010] (2) Preparation of Ni / FCC catalyst

[0011] Immerse the FCC particles pretreated in step (1) in a nickel nitrate solution, then dry and place them in a sodium borohydride solution for reduction to obtain Ni / FCC catalyst particles;

[0012] (3) Preparation of Ni / FCC-CNTs

[0013] Place the Ni / FCC catalyst particles obtained in step (2) in a formaldehyde reforming hydrogen production reactor, and grow carbon nanotubes at 500 - 600 °C by the formaldehyde reforming hydrogen production reaction to obtain Ni / FCC-CNTs particles with carbon nanotubes grown on them;

[0014] (4) Preparation of FCC-CNTs deodorant:

[0015] Place the Ni / FCC-CNTs particles obtained in step (3) in a perchloric acid solution to remove Ni to obtain FCC-CNTs particles, and then place the taken-out FCC-CNTs particles in an atmosphere furnace for heating, and introduce a mixed gas of steam and nitrogen, and finally obtain the FCC-CNTs deodorant.

[0016] In the above method: the mass fraction of the nickel nitrate solution described in step (2) is 10 - 20%, and the mass fraction of the sodium borohydride solution is 5 - 10%;

[0017] In step (2), the mass ratio of the pretreated FCC particles, nickel nitrate solution and sodium borohydride solution is 1:(5 - 8):(10 - 20).

[0018] In the above method: the formaldehyde solution in the formaldehyde reforming hydrogen production reactor described in step (3) is mixed with nitrogen through a flow pump and a flow meter and enters a tubular furnace, and the Ni / FCC catalyst is placed in the middle of the tubular furnace to form a formaldehyde reforming hydrogen production reaction.

[0019] In the above method: the mass fraction of the formaldehyde solution in the formaldehyde reforming hydrogen production reaction described in step (3) is 20 - 25%, the flow rate of the formaldehyde solution entering the tubular furnace of the reactor is (4 - 6) mL / h, and the flow rate of nitrogen entering the tubular furnace of the reactor is (50 - 90) mL / min.

[0020] In the above method: the time for growing carbon nanotubes in step (3) is 12 to 24 h.

[0021] In the above method: the mass fraction of the perchloric acid solution in step (4) is 30 to 50%, and the mass ratio of the Ni / FCC-CNTs particles to the perchloric acid solution is 1:(4 to 6).

[0022] In the above method: the heating temperature in step (4) is 160 to 180 °C, and the heating time is 4 to 6 h; the volume ratio of water vapor to nitrogen is (1 to 2):(8 to 9), and the flow rate of the mixed gas of water vapor and nitrogen introduced is (60 to 80) mL / min.

[0023] An odor removal adsorbent for kitchen waste, which is prepared by the above method.

[0024] In the technical solution of the present invention, the application of the adsorbent in the odor removal of kitchen waste.

[0025] In the above preparation method: the formaldehyde reforming hydrogen production reactor in step (3) is composed of a formaldehyde solution, a flow pump, a tubular furnace, a nitrogen cylinder and a flow meter. The formaldehyde solution and nitrogen are mixed and enter the tubular furnace through the flow meter via the flow pump. The Ni / FCC catalyst is placed in the middle of the tubular furnace to form a formaldehyde reforming hydrogen production reaction.

[0026] The odor removal adsorption experiment and results of the present invention: Take 2 g of the odor removal adsorbent and load it into a quartz tube with an inner diameter of 10 mm, and introduce a mixed gas of H2S (volume concentration of 100 ppm), O2 (volume concentration of 20%) and N2 into the quartz tube. The introduction rate of the mixed gas is 50 mL / min. Detect the concentration of H2S in the tail gas at room temperature of 25 °C, and record the time when the H2S concentration is higher than 10 ppm (abbreviated as t 90 ). At room temperature of 25 °C, the t 90 of this odor removal adsorbent is higher than 20 h.

[0027] Beneficial effects: The present invention can not only eliminate the odor in the process of kitchen waste disposal, but also solve the problem of resource utilization of waste FCC catalysts. The adsorbent is environmentally friendly, has high mechanical strength, large adsorption capacity, and the odor can be easily desorbed. The adsorbent can be reused, and has strong application promotion value and broad market prospects. Specific embodiments

[0028] The following further illustrates the present invention in conjunction with embodiments, but the protection scope of the present invention is not limited thereto:

[0029] The waste FCC catalyst is a ultra-stable Y zeolite (USY) catalyst used for catalytic cracking of heavy oil for three years. The impurities it contains are heavy metal ions and coke deposits, which reduce the catalytic cracking activity to 40%, thus unable to meet the design requirements.

[0030] Example 1

[0031] (1) Pretreatment of waste FCC catalyst

[0032] The waste FCC catalyst is ball-milled and crushed, and the waste FCC catalyst particles with a mesh size of 20 - 40 are screened out. Then, 100 g of the waste FCC catalyst particles are immersed in 1000 g of deionized water at a temperature of 40°C for 30 min, taken out and then immersed in 1000 g of deionized water at a temperature of 40°C for 30 min, taken out and then immersed in 1000 g of deionized water at a temperature of 40°C for 30 min. Finally, it is taken out and dried in an oven at 60°C for 24 h to obtain FCC particles;

[0033] (2) Preparation of Ni / FCC catalyst

[0034] 50 g of the FCC particles obtained in step (1) are impregnated in 250 g of a nickel nitrate solution with a mass fraction of 10% for 30 min, then placed in an oven at 80°C for 12 h and then placed in 500 g of a sodium borohydride solution with a mass fraction of 5% to reduce the adsorbed nickel nitrate to obtain Ni / FCC catalyst particles;

[0035] (3) Preparation of Ni / FCC-CNTs

[0036] 10 g of the Ni / FCC catalyst particles obtained in step (2) are placed in the middle of a formaldehyde reforming hydrogen production reactor. The reactor temperature is raised to 500°C, and a formaldehyde solution with a mass fraction of 20% and a protective gas nitrogen are introduced to carry out the formaldehyde reforming hydrogen production reaction for 12 h. The flow rate of the formaldehyde solution entering the tubular furnace is 4 mL / h, and the flow rate of nitrogen entering the tubular furnace is 50 mL / min to obtain Ni / FCC-CNTs particles grown with carbon nanotubes;

[0037] (4) Preparation of FCC-CNTs deodorant

[0038] Weigh 5 g of the Ni / FCC-CNTs particles obtained in step (3) and place them in 20 g of a perchloric acid solution with a mass fraction of 30%. Soak for 1 h to remove Ni and obtain FCC-CNTs particles. Then, place the taken-out FCC-CNTs particles in an atmosphere furnace for heating, and introduce a mixed gas of steam and nitrogen. The heating temperature is 160 °C, and the heating time is 4 h. Finally, an FCC-CNTs deodorant is obtained, where the volume ratio of steam to nitrogen is 0.1:0.9, and the flow rate of the introduced mixed gas of steam and nitrogen is 60 mL / min;

[0039] (5) Adsorption performance test

[0040] Take 2 g of the deodorant adsorbent and load it into a quartz tube with an inner diameter of 10 mm. Then, introduce a mixed gas of H2S (volume concentration of 100 ppm), O2 (volume concentration of 20%), and N2 into the quartz tube. The introduction rate of the mixed gas is 50 mL / min. At room temperature of 25 °C, detect the concentration of H2S in the tail gas and record the time when the H2S concentration is higher than 10 ppm (abbreviated as t 90 ). At room temperature of 25 °C, the t 90 of this deodorant adsorbent is 22.5 h.

[0041] Example 2

[0042] (1) Pretreatment of waste FCC catalyst

[0043] Ball-mill and crush the waste FCC catalyst, and screen out waste FCC catalyst particles with a mesh size of 20 - 40. Then, weigh 100 g of the waste FCC catalyst particles and soak them in 2000 g of deionized water at a temperature of 60 °C. After soaking for 30 min, take them out and place them in 2000 g of deionized water at a temperature of 60 °C again. After soaking for 30 min, take them out and place them in 2000 g of deionized water at a temperature of 60 °C again. Soak for 30 min, and finally take them out and dry them in an oven at 80 °C for 12 h to obtain FCC particles;

[0044] (2) Preparation of Ni / FCC catalyst

[0045] Weigh 50 g of the FCC particles obtained in step (1) and impregnate them in 400 g of a nickel nitrate solution with a mass fraction of 20%. After impregnating for 30 min, place them in an oven at 60 °C for drying for 24 h, and then place them in 1000 g of a sodium borohydride solution with a mass fraction of 10% to reduce the adsorbed nickel nitrate to obtain Ni / FCC catalyst particles;

[0046] (3) Preparation of Ni / FCC-CNTs

[0047] Weigh 10 g of the Ni / FCC catalyst particles obtained in step (2) and place them in the middle of the formaldehyde reforming hydrogen production reactor. Raise the reactor temperature to 600 °C, and introduce a formaldehyde solution with a mass fraction of 25% and a protective gas nitrogen to carry out the formaldehyde reforming hydrogen production reaction for 24 h. The flow rate of the formaldehyde solution into the tubular furnace is 6 mL / h, and the flow rate of nitrogen into the tubular furnace is 90 mL / min to obtain Ni / FCC-CNTs particles grown with carbon nanotubes;

[0048] (4) Preparation of FCC-CNTs deodorant

[0049] Weigh 5 g of the Ni / FCC-CNTs particles obtained in step (3) and place them in 30 g of a perchloric acid solution with a mass fraction of 50%. Soak for 1 h to remove Ni to obtain FCC-CNTs particles. Then, place the taken-out FCC-CNTs particles in an atmosphere furnace for heating, and introduce a mixed gas of water vapor and nitrogen. The heating temperature is 180 °C, and the heating time is 6 h to finally obtain the FCC-CNTs deodorant. The volume ratio of water vapor to nitrogen is 0.2:0.8, and the flow rate of the mixed gas of water vapor and nitrogen introduced is 80 mL / min;

[0050] (5) Adsorption performance test

[0051] Take 2 g of the deodorant adsorbent and load it into a quartz tube with an inner diameter of 10 mm. Introduce a mixed gas of H2S (volume concentration of 100 ppm), O2 (volume concentration of 20%), and N2 into the quartz tube. The introduction rate of the mixed gas is 50 mL / min. Detect the concentration of H2S in the tail gas at room temperature of 25 °C, and record the time when the H2S concentration is higher than 10 ppm (abbreviated as t 90 ). At room temperature of 25 °C, the t 90 of this deodorant adsorbent is 26 h.

[0052] Example 3

[0053] (1) Pretreatment of waste FCC catalyst

[0054] Ball mill and crush the waste FCC catalyst, and screen out waste FCC catalyst particles with a mesh size of 20 - 40. Then, weigh 100 g of the waste FCC catalyst particles and soak them in 2000 g of deionized water at a temperature of 40 °C for 30 min. Take them out and then place them in 2000 g of deionized water at a temperature of 60 °C for 30 min. Take them out and then place them in 2000 g of deionized water at a temperature of 40 °C for 30 min. Finally, take them out and dry them in an oven at 80 °C for 24 h to obtain FCC particles;

[0055] (2) Preparation of Ni / FCC catalyst

[0056] Weigh 50 g of the FCC particles obtained in step (1) and immerse them in 400 g of a nickel nitrate solution with a mass fraction of 15%. After immersion for 30 min, place them in an oven and dry at 60 °C for 24 h, then place them in 1000 g of a sodium borohydride solution with a mass fraction of 7% to reduce the adsorbed nickel nitrate to obtain Ni / FCC catalyst particles;

[0057] (3) Preparation of Ni / FCC-CNTs

[0058] Weigh 10 g of the Ni / FCC catalyst particles obtained in step (2) and place them in the middle of a formaldehyde reforming hydrogen production reactor. Raise the reactor temperature to 600 °C, and introduce a formaldehyde solution with a mass fraction of 23% and a protective gas nitrogen to carry out the formaldehyde reforming hydrogen production reaction for 18 h. The flow rate of the formaldehyde solution entering the tubular furnace is 6 mL / h, and the flow rate of nitrogen entering the tubular furnace is 80 mL / min to obtain Ni / FCC-CNTs particles grown with carbon nanotubes;

[0059] (4) Preparation of FCC-CNTs deodorant

[0060] Weigh 5 g of the Ni / FCC-CNTs particles obtained in step (3) and place them in 30 g of a perchloric acid solution with a mass fraction of 40%. Soak for 1 h to remove Ni to obtain FCC-CNTs particles. Then, place the taken-out FCC-CNTs particles in an atmosphere furnace and heat, and introduce a mixed gas of water vapor and nitrogen. The heating temperature is 170 °C, and the heating time is 6 h to finally obtain FCC-CNTs deodorant, where the volume ratio of water vapor to nitrogen is 0.2:0.8, and the flow rate of the introduced mixed gas of water vapor and nitrogen is 80 mL / min;

[0061] (5) Adsorption performance test

[0062] Take 2 g of the deodorant adsorbent and load it into a quartz tube with an inner diameter of 10 mm, and introduce a mixed gas of H2S (volume concentration of 100 ppm), O2 (volume concentration of 20%) and N2 into the quartz tube. The introduction rate of the mixed gas is 50 mL / min. Detect the concentration of H2S in the tail gas at room temperature of 25 °C, and record the time when the H2S concentration is higher than 10 ppm (abbreviated as t 90 ). At room temperature of 25 °C, the t 90 of this deodorant adsorbent is 23.5 h.

[0063] Example 4

[0064] (1) Pretreatment of waste FCC catalyst

[0065] The waste FCC catalyst was ball-milled and crushed, and the waste FCC catalyst particles with a mesh size of 20 - 40 were screened out. Then, 100 g of the waste FCC catalyst particles were weighed and immersed in 2000 g of deionized water at a temperature of 40°C for 30 min. After that, they were taken out and placed in 2000 g of deionized water at a temperature of 60°C for 30 min. Then, they were taken out again and placed in 2000 g of deionized water at a temperature of 40°C for 30 min. Finally, they were taken out and dried in an oven at 80°C for 24 h to obtain FCC particles;

[0066] (2) Preparation of Ni / FCC catalyst

[0067] 50 g of the FCC particles obtained in step (1) were weighed and impregnated in 400 g of a nickel nitrate solution with a mass fraction of 15%. After impregnation for 30 min, they were placed in an oven and dried at 60°C for 24 h, and then placed in 1000 g of a sodium borohydride solution with a mass fraction of 7% to reduce the adsorbed nickel nitrate to obtain Ni / FCC catalyst particles;

[0068] (3) Preparation of Ni / FCC-CNTs

[0069] 10 g of the Ni / FCC catalyst particles obtained in step (2) were placed in the middle of a formaldehyde reforming hydrogen production reactor. The reactor temperature was raised to 550°C, and a formaldehyde solution with a mass fraction of 23% and a protective gas nitrogen were introduced to carry out the formaldehyde reforming hydrogen production reaction for 18 h. The flow rate of the formaldehyde solution entering the tubular furnace was 6 mL / h, and the flow rate of nitrogen entering the tubular furnace was 80 mL / min to obtain Ni / FCC-CNTs particles grown with carbon nanotubes;

[0070] (4) Preparation of FCC-CNTs deodorant

[0071] 5 g of the Ni / FCC-CNTs particles obtained in step (3) were placed in 30 g of a perchloric acid solution with a mass fraction of 40% and soaked for 1 h to remove Ni to obtain FCC-CNTs particles. Then, the taken-out FCC-CNTs particles were placed in an atmosphere furnace and heated, and a mixed gas of steam and nitrogen was introduced. The heating temperature was 170°C, and the heating time was 6 h. Finally, FCC-CNTs deodorant was obtained, where the volume ratio of steam to nitrogen was 0.2:0.8, and the flow rate of the mixed gas of steam and nitrogen introduced was 80 mL / min;

[0072] (5) Adsorption performance test

[0073] Take 2 g of the deodorant adsorbent and place it in a quartz tube with an inner diameter of 10 mm. Then, introduce a mixed gas of H2S (volume concentration of 100 ppm), O2 (volume concentration of 20%), and N2 into the quartz tube at a flow rate of 50 mL / min. Measure the concentration of H2S in the tail gas at room temperature of 25°C and record the time (abbreviated as t 90 ) when the H2S concentration is higher than 10 ppm. At room temperature of 25°C, the t 90 of this deodorant adsorbent is 24 h.

[0074] Example 5

[0075] (1) Pretreatment of waste FCC catalyst

[0076] Ball-mill and crush the waste FCC catalyst, and screen out waste FCC catalyst particles with a mesh size of 20 - 40. Then, weigh 100 g of the waste FCC catalyst particles and soak them in 2000 g of deionized water at a temperature of 40°C for 30 min. After taking them out, place them in 2000 g of deionized water at a temperature of 60°C for 30 min. Then, take them out and place them in 2000 g of deionized water at a temperature of 40°C for 30 min. Finally, take them out and dry them in an oven at 80°C for 24 h to obtain FCC particles;

[0077] (2) Preparation of Ni / FCC catalyst

[0078] Weigh 50 g of the FCC particles obtained in step (1) and immerse them in 400 g of a nickel nitrate solution with a mass fraction of 12%. After impregnation for 30 min, place them in an oven at 60°C and dry for 24 h. Then, place them in 1000 g of a sodium borohydride solution with a mass fraction of 7% to reduce the adsorbed nickel nitrate to obtain Ni / FCC catalyst particles;

[0079] (3) Preparation of Ni / FCC-CNTs

[0080] Weigh 10 g of the Ni / FCC catalyst particles obtained in step (2) and place them in the middle of a formaldehyde reforming hydrogen production reactor. Raise the reactor temperature to 580°C, and introduce a formaldehyde solution with a mass fraction of 23% and a protective gas of nitrogen to carry out the formaldehyde reforming hydrogen production reaction for 18 h. The flow rate of the formaldehyde solution into the tubular furnace is 6 mL / h, and the flow rate of nitrogen into the tubular furnace is 80 mL / min to obtain Ni / FCC-CNTs particles with carbon nanotubes grown on them;

[0081] (4) Preparation of FCC-CNTs deodorant

[0082] Weigh 5 g of the Ni / FCC-CNTs particles obtained in step (3) and place them in 30 g of a perchloric acid solution with a mass fraction of 40%. Soak for 1 h to remove Ni and obtain FCC-CNTs particles. Then, place the taken-out FCC-CNTs particles in an atmosphere furnace for heating, and introduce a mixed gas of steam and nitrogen. The heating temperature is 170 °C, and the heating time is 6 h. Finally, obtain the FCC-CNTs deodorant, where the volume ratio of steam to nitrogen is 0.2:0.8, and the flow rate of the introduced mixed gas of steam and nitrogen is 80 mL / min;

[0083] (5) Adsorption performance test

[0084] Take 2 g of the deodorant adsorbent and load it into a quartz tube with an inner diameter of 10 mm. Then, introduce a mixed gas of H2S (volume concentration of 100 ppm), O2 (volume concentration of 20%), and N2 into the quartz tube. The introduction rate of the mixed gas is 50 mL / min. At room temperature of 25 °C, detect the concentration of H2S in the tail gas, and record the time when the H2S concentration is higher than 10 ppm (abbreviated as t 90 ). At room temperature of 25 °C, the t 90 of this deodorant adsorbent is 22 h 20 min.

[0085] Comparative example 1

[0086] (1) Preparation of the deodorant adsorbent

[0087] Except that in step (4) during the preparation of the deodorant adsorbent, the FCC-CNTs particles are not placed in the atmosphere furnace for heating, and other conditions are the same as in Example 1;

[0088] (2) Adsorption performance test

[0089] Take 2 g of the deodorant adsorbent and load it into a quartz tube with an inner diameter of 10 mm. Then, introduce a mixed gas of H2S (volume concentration of 100 ppm), O2 (volume concentration of 20%), and N2 into the quartz tube. The introduction rate of the mixed gas is 50 mL / min. At room temperature of 25 °C, detect the concentration of H2S in the tail gas, and record the time when the H2S concentration is higher than 10 ppm (abbreviated as t 90 )。At room temperature of 25 °C, the t 90 of this deodorant adsorbent is 13.5 h;

[0090] (3) Comparative effect

[0091] Compared with Example 1, in step (4) during the preparation of the deodorant adsorbent, the FCC-CNTs particles are not placed in the atmosphere furnace for heating, and the deodorant adsorbent does not react with steam at 160 °C to increase the hydroxyl concentration on the adsorbent surface. The hydroxyl concentration on the adsorbent surface that can form hydrogen bonds with H2S is not high. Therefore, the adsorption performance decreases significantly.

[0092] Comparative Example 2

[0093] (1) Preparation of deodorant adsorbent

[0094] Except that in step (3) of the preparation of the deodorant adsorbent, the Ni / FCC catalyst particles are not placed in the formaldehyde reforming hydrogen production reactor to grow carbon nanotubes, other conditions are the same as in Example 2;

[0095] (2) Adsorption performance test

[0096] Take 2 g of the deodorant adsorbent and load it into a quartz tube with an inner diameter of 10 mm. Then, a mixed gas of H2S (volume concentration of 100 ppm), O2 (volume concentration of 20%), and N2 is introduced into the quartz tube at a flow rate of 50 mL / min. At room temperature of 25°C, the concentration of H2S in the tail gas is detected, and the time when the H2S concentration is higher than 10 ppm is recorded (abbreviated as t 90 ). At room temperature of 25°C, the t 90 of this deodorant adsorbent is 0.2 h;

[0097] (3) Comparative effect

[0098] Compared with Example 2, in step (3) of the preparation of the deodorant adsorbent, the Ni / FCC catalyst particles are not placed in the formaldehyde reforming hydrogen production reactor to grow carbon nanotubes, and carbon nanotubes with a large specific surface area and a rich pore structure cannot be generated in the deodorant adsorbent, resulting in a sharp decline in its adsorption performance.

Claims

1. A preparation method of a deodorant adsorbent for kitchen waste, characterized in that: The preparation method is as follows: (1) Pretreatment of waste FCC catalyst The waste FCC catalyst is ball-milled and crushed, and waste FCC catalyst particles with a mesh size of 20 - 40 are screened out, washed and then dried for standby; (2) Preparation of Ni / FCC catalyst The FCC particles pretreated in step (1) are impregnated in a nickel nitrate solution, then dried and placed in a sodium borohydride solution for reduction to obtain Ni / FCC catalyst particles; (3) Preparation of Ni / FCC-CNTs The Ni / FCC catalyst particles obtained in step (2) are placed in a formaldehyde reforming hydrogen production reactor, and carbon nanotubes are grown at 500 - 600 °C by the formaldehyde reforming hydrogen production reaction to obtain Ni / FCC-CNTs particles with carbon nanotubes grown on them; (4) Preparation of FCC-CNTs deodorant: The Ni / FCC-CNTs particles obtained in step (3) are placed in a perchloric acid solution to remove Ni to obtain FCC-CNTs particles, and then the taken-out FCC-CNTs particles are heated in an atmosphere furnace, and a mixed gas of water vapor and nitrogen is introduced to finally obtain the FCC-CNTs deodorant.

2. The preparation method of the deodorant adsorbent for kitchen waste according to claim 1, characterized in that: In step (2), the mass fraction of the nickel nitrate solution is 10 - 20%, and the mass fraction of the sodium borohydride solution is 5 - 10%; In step (2), the mass ratio of the pretreated FCC particles, nickel nitrate solution and sodium borohydride solution is 1:(5 - 8):(10 - 20).

3. The preparation method of the deodorant adsorbent for kitchen waste according to claim 1, characterized in that: In step (3), the formaldehyde solution and nitrogen in the formaldehyde reforming hydrogen production reactor are mixed and enter the tubular furnace, and the Ni / FCC catalyst is placed in the middle of the tubular furnace to form a formaldehyde reforming hydrogen production reaction.

4. The preparation method of the deodorant adsorbent for kitchen waste according to claim 3, characterized in that: In step (3), the mass fraction of the formaldehyde solution in the formaldehyde reforming hydrogen production reaction is 20 - 25%, the flow rate of the formaldehyde solution entering the tubular furnace of the reactor is (4 - 6) mL / h, and the flow rate of nitrogen entering the tubular furnace of the reactor is (50 - 90) mL / min.

5. The preparation method of the deodorant adsorbent for kitchen waste according to claim 1, characterized in that: In step (3), the time for growing carbon nanotubes is 12 - 24 h.

6. The preparation method of the deodorant adsorbent for kitchen waste according to claim 1, characterized in that: In step (4), the mass fraction of the perchloric acid solution is 30 - 50%, and the mass ratio of the Ni / FCC-CNTs particles to the perchloric acid solution is 1:(4 - 6).

7. The preparation method of the deodorant adsorbent for kitchen waste according to claim 1, wherein: In step (4), the heating temperature is 160 - 180 °C, the heating time is 4 - 6 h; the volume ratio of water vapor to nitrogen is (1 - 2):(8 - 9), and the flow rate of the mixed gas of water vapor and nitrogen introduced is (60 - 80) mL / min.

8. A deodorizing adsorbent for kitchen waste, characterized in that: This adsorbent is prepared by any one of the methods of claims 1 - 7.

9. Application of the adsorbent according to claim 8 in deodorizing kitchen waste.