A method for preparing carbon dioxide absorbent using spent hydrogenation catalyst

Abstract

This invention provides a method for preparing a carbon dioxide absorbent using spent hydrogenation catalyst. The method includes sequentially subjecting the original spent hydrogenation catalyst to calcination for decarburization and pore-expansion treatment, washing for demetallization treatment, alkaline earth metal oxide modification treatment, and alkali metal carbonate loading treatment. Furthermore, this invention also provides the application of the carbon dioxide absorbent obtained by the above method and its use in at least one of the processes of absorbing carbon dioxide, reducing carbon dioxide emissions, and achieving carbon neutrality. Through the above technical solutions, this invention solves the problem of recycling and treating spent hydrogenation catalysts and provides a low-cost, high-efficiency carbon dioxide absorption material.

Description

Technical Field

[0001] This invention relates to the field of materials, and more specifically, to a method for preparing a carbon dioxide absorbent using a waste hydrogenation catalyst, the carbon dioxide absorbent prepared by this method, and its applications. Background Technology

[0002] Carbon dioxide absorbent materials can adsorb and fix carbon dioxide generated in industrial production, thereby reducing carbon dioxide emissions. Therefore, they have important application value for achieving the goal of "carbon neutrality".

[0003] Solid adsorbents using alkali metal carbonates as the active component and porous materials as the carrier can serve as carbon dioxide absorption materials. The alkali metal carbonates can absorb carbon dioxide at 50–100°C in the presence of water vapor, generating bicarbonate. At 120–300°C, the solid material that has absorbed carbon dioxide decomposes, releasing carbon dioxide and thus achieving regeneration and recycling. A wide range of porous materials can be selected as the carrier, including activated carbon, alumina, molecular sieves, and silica aerogels. This solid adsorbent can be used in various scenarios, such as carbon dioxide capture in flue gas from wet desulfurization processes in coal-fired power plants and flue gas from natural gas power plants.

[0004] CN108295802A discloses a potassium-based CO2 absorbent particle, which includes an active component and a carrier; the active component is potassium carbonate, and the carrier is activated alumina, calcium aluminate cement, kaolin, or aluminum hydroxide; the potassium-based CO2 absorbent particle is a spherical particle, which can be used to remove CO2 from coal-fired flue gas.

[0005] However, the test results showed that the carbon dioxide absorption efficiency of existing carbon dioxide absorption materials still needs to be further improved. Summary of the Invention

[0006] The purpose of this invention is to further improve the carbon dioxide absorption efficiency of carbon dioxide absorption materials.

[0007] To achieve the above objectives, the present invention provides a method for preparing a carbon dioxide absorbent using a spent hydrogenation catalyst. The method includes: calcining and decarbonizing the original spent hydrogenation catalyst to obtain a calcined, decarbonized, and expanded-pore spent hydrogenation catalyst; the original spent hydrogenation catalyst includes an alumina support and a metal component, the metal component including a hydrogenation-active metal component supported on a fresh hydrogenation catalyst and metal impurities deposited on the alumina support during hydrogenation; washing and demetallizing the calcined, decarbonized, and expanded-pore spent hydrogenation catalyst to obtain a washed and demetallized spent hydrogenation catalyst; modifying the washed and demetallized spent hydrogenation catalyst with alkaline earth metal oxides to obtain an alkaline earth metal oxide-modified spent hydrogenation catalyst; and loading the alkaline earth metal oxide-modified spent hydrogenation catalyst with alkali metal carbonates to obtain an alkali metal carbonate-loaded spent hydrogenation catalyst.

[0008] On the other hand, the present invention also provides a carbon dioxide absorbent obtained by the method described above.

[0009] On the other hand, the present invention also provides the application of the carbon dioxide absorbent as described above in at least one of the processes of absorbing carbon dioxide, reducing carbon dioxide emissions, and achieving carbon neutrality.

[0010] Through the above technical solution, this invention utilizes the promoting effect of alkaline earth metal oxide modification and metal deposited on the spent hydrogenation catalyst during hydrogenation on CO2 adsorption. This avoids the blockage of the alumina support pore structure by excessive metal deposited on the spent hydrogenation catalyst during hydrogenation, thus helping to improve carbon dioxide absorption efficiency. It is particularly suitable as a support for the preparation of carbon dioxide absorbent materials with alkali metal carbonates as the active component. On the one hand, it solves the problem of recycling and treating spent hydrogenation catalysts; on the other hand, it provides a low-cost, high-efficiency carbon dioxide absorbent material. The carbon dioxide absorbent prepared by the method of this invention is simple to prepare, the support is derived from spent hydrogenation catalyst, the cost is low, it has significant environmental benefits, and has high application value.

[0011] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0012] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0013] This invention provides a method for preparing a carbon dioxide absorbent using a spent hydrogenation catalyst. The method includes: calcining the original spent hydrogenation catalyst to decarbonize and expand its pores, obtaining a calcined, decarbonized, and expanded spent hydrogenation catalyst; the original spent hydrogenation catalyst includes an alumina support and a metal component, the metal component including a hydrogenation-active metal component supported on a fresh hydrogenation catalyst and metal impurities deposited on the alumina support during hydrogenation; washing and demetallizing the calcined, decarbonized, and expanded spent hydrogenation catalyst, obtaining a washed and demetallized spent hydrogenation catalyst; modifying the washed and demetallized spent hydrogenation catalyst with alkaline earth metal oxides, obtaining an alkaline earth metal oxide-modified spent hydrogenation catalyst; and loading the alkaline earth metal oxide-modified spent hydrogenation catalyst with alkali metal carbonates, obtaining an alkali metal carbonate-loaded spent hydrogenation catalyst.

[0014] Optionally, based on the total amount of the original waste hydrogenation catalyst, the content of metal impurities deposited on the alumina support during the hydrogenation process can be 20-80 wt%, preferably 25-60 wt%.

[0015] Optionally, the metallic impurities deposited on the alumina support during hydrogenation include at least one of nickel, vanadium, calcium, and iron. Typically, nickel, vanadium, calcium, and iron all deposit during hydrogenation; therefore, in most cases, the metallic impurities deposited on the alumina support during hydrogenation include nickel, vanadium, calcium, and iron.

[0016] Optionally, the pore volume of the original spent hydrogenation catalyst is 0.02-0.8 mL / g, and the specific surface area is 10-200 m². 2 / g, with the most probable pore diameter being 1-15nm.

[0017] Optionally, the original waste hydrogenation catalyst can refer to the waste hydrogenation catalyst discharged from the hydrogenation unit, and its source includes at least one of waste gasoline hydrogenation catalyst, waste diesel hydrogenation catalyst, waste coal tar hydrogenation catalyst, waste wax oil hydrogenation catalyst, and waste residue oil hydrogenation catalyst. Preferably, the source of the original waste hydrogenation catalyst includes waste residue oil hydrogenation catalyst, which contains more vanadium, making it more conducive to carbon dioxide absorption.

[0018] Optionally, the fresh hydrogenation catalyst corresponding to the original spent hydrogenation catalyst contains a hydrogenation-active metal component, which includes at least one Group VIB metal element and at least one Group VIII metal element; preferably, the Group VIB metal element is molybdenum and / or tungsten; preferably, the Group VIII metal element is nickel and / or cobalt. Based on the total amount of the fresh hydrogenation catalyst, the content of the Group VIB metal component, calculated as oxide, is 0.2-30% by weight, preferably 1-20% by weight; the content of the Group VIII metal element, calculated as oxide, is 0.1-10% by weight, preferably 0.3-8% by weight.

[0019] Optionally, based on the total amount of the original waste hydrogenation catalyst, the metal impurities deposited on the alumina support during the hydrogenation process include 5-40 wt% Ni, 5-50 wt% V, 1-12 wt% Fe, and 0.1-1 wt% Ca.

[0020] Optionally, the roasting, decarburization, and pore-expanding treatment includes: subjecting the original waste hydrogenation catalyst to a first heat treatment, a second heat treatment, and a third heat treatment in an oxygen-containing atmosphere; wherein the oxygen content in the oxygen-containing atmosphere is 8-30% by volume, preferably 10-25%.

[0021] Optionally, the conditions for the first heat treatment include: a temperature of 100-250℃ and a time of 1-5 hours; the conditions for the second heat treatment include: a temperature of 300-450℃ and a time of 1-5 hours; and the conditions for the third heat treatment include: a temperature of 500-800℃ and a time of 1-5 hours.

[0022] Preferably, the conditions for the first heat treatment include: treatment at a temperature of 150-200℃ for 1-3 hours; the conditions for the second heat treatment include: treatment at a temperature of 350-420℃ for 1-3 hours; and the conditions for the third heat treatment include: treatment at a temperature of 600-750℃ for 1-3 hours.

[0023] Optionally, the washing and demetallization process includes: contacting the calcined, decarburized, and pore-expanded waste hydrogenation catalyst with a washing solution for washing, followed by solid-liquid separation to obtain washing waste liquid and the washed and demetallized waste hydrogenation catalyst; the washing solution is an acid solution or an alkaline solution.

[0024] Optionally, the pore volume of the washed and demetallized spent hydrogenation catalyst is 0.2-1.0 mL / g, preferably 0.3-0.8 mL / g, and the specific surface area is 50-300 m² / g. 2 / g, preferably 100-200m 2 / g, with a most probable pore size of 5-15nm, preferably 8-12nm, and a carbon content of less than 3% by weight, preferably less than 1% by weight.

[0025] Optionally, the content of the metal impurities in the original waste hydrogenation catalyst is 1.5-5 times, preferably 2-3 times, the content of the metal impurities in the waste catalyst after washing and demetallization treatment.

[0026] Optionally, the concentration of acid in the acid solution is 10-98 wt%; and the concentration of alkali in the alkaline solution is 10-60 wt%.

[0027] Optionally, the amount of the washing solution used is 200-1000 parts by weight relative to 100 parts by weight of the calcined, decarburized, and pore-expanded waste hydrogenation catalyst.

[0028] Optionally, the acid is at least one selected from sulfuric acid, nitric acid, hydrochloric acid, oxalic acid, citric acid, and tartaric acid.

[0029] Optionally, the alkali is at least one selected from ammonia monohydrate, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate. The term "alkali" generally refers to substances whose aqueous solutions are alkaline.

[0030] Optionally, the washing conditions include a temperature of 1-100℃ and a time of 0.5-10 hours. Preferably, to achieve better carbon dioxide adsorption, the washing time is preferably 1-5 hours. Under this preferred condition, excessive residual metal impurities can be avoided, which is detrimental to the carbon dioxide adsorption effect. Furthermore, excessive loss of alumina carrier and metal impurities can also be avoided, which would impair the carbon dioxide adsorption effect.

[0031] Optionally, the content of the metal impurities in the waste hydrogenation catalyst after washing and demetallization is 2-30 wt%, preferably 6-25 wt%.

[0032] Optionally, the method further includes: extracting metals from the washing waste liquid; specifically, the operation of extracting metals from the washing waste liquid may include: stepwise precipitation, filtration, washing, pH adjustment, ion exchange, solvent extraction, etc.

[0033] Optionally, the alkaline earth metal oxide modification process includes: first impregnating the washed and demetallized waste hydrogenation catalyst with a first impregnation solution containing alkaline earth metal elements and performing solid-liquid separation to obtain the first impregnated waste hydrogenation catalyst; and first drying and first calcining the first impregnated waste hydrogenation catalyst to obtain the alkaline earth metal oxide modified waste hydrogenation catalyst.

[0034] Optionally, the amount of alkaline earth metal element, calculated as oxide, is 0.5-10 parts by weight relative to 100 parts by weight of the washed and demetallized waste hydrogenation catalyst, preferably 1-8 parts by weight.

[0035] Optionally, the first impregnation can be an equal-volume saturated impregnation, an unsaturated impregnation, or a supersaturated impregnation.

[0036] Optionally, the conditions for the first drying include: a temperature of 80-150°C and a time of 2-8 hours.

[0037] Optionally, the conditions for the first calcination include: a temperature of 200-600℃ and a time of 2-8 hours.

[0038] Optionally, the first impregnation solution contains at least one of magnesium nitrate, beryllium nitrate, calcium nitrate, strontium nitrate, and barium nitrate.

[0039] Optionally, the alkali metal carbonate loading treatment includes: using the waste hydrogenation catalyst modified with alkaline earth metal oxide as a support and subjecting it to a second impregnation with a second impregnation solution containing active components, followed by solid-liquid separation to obtain a second impregnated support, wherein the active components are alkali metal carbonates and / or alkali metal bicarbonates; subjecting the second impregnated support to a second drying and a second calcination to obtain a second calcined material.

[0040] Optionally, the amount of the active ingredient is 10-40 parts by weight, preferably 20-30 parts by weight, relative to 100 parts by weight of the carrier.

[0041] Optionally, each of the second impregnations can be an equal-volume saturated impregnation, an unsaturated impregnation, or a supersaturated impregnation.

[0042] Optionally, the conditions for the second drying include: a temperature of 80-120°C and a time of 2-8 hours.

[0043] Optionally, the conditions for the second calcination include: a temperature of 120-200℃ and a time of 2-8 hours.

[0044] The present invention also provides a carbon dioxide absorbent obtained by the method described above.

[0045] The present invention also provides the application of the carbon dioxide absorbent as described above in at least one of the processes of absorbing carbon dioxide, reducing carbon dioxide emissions, and achieving carbon neutrality.

[0046] For example, carbon dioxide absorbent can be used in flue gas treatment devices to absorb carbon dioxide in flue gas. After carbon dioxide absorption saturation, carbon dioxide can be released through heating to regenerate the carbon dioxide absorbent. The regenerated carbon dioxide absorbent can then be used again to absorb carbon dioxide in flue gas.

[0047] The present invention will be further described in detail below through embodiments. Unless otherwise specified, the raw materials used in the embodiments are all commercially available.

[0048] Example 1

[0049] Weigh 100g of waste oil hydrogenation catalyst (the amount of Fe, Ca, Ni, V and other metals deposited on the alumina support during the hydrogenation process is 43.9wt%, the pore volume is 0.11mL / g, and the specific surface area is 44m²). 2 The raw spent hydrogenation catalyst (with a pore size of 6 nm and a corresponding active metal component of 8 wt% MoO3 and 2 wt% NiO) was used as the initial spent hydrogenation catalyst. It was calcined in air using a programmed temperature rise process: from room temperature to 150 °C, held for 2 hours, then to 350 °C, held for 2 hours, and finally to 600 °C, held for 3 hours, yielding the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. A 20 wt% citric acid aqueous solution was used as the washing solution to impregnate the calcined, decarburized, and pore-expanded spent hydrogenation catalyst at room temperature for 2 hours. The amount of washing solution used was 500 parts by weight per 100 parts by weight of the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. The filtered residue was dried at 120 °C to obtain the washed and demetallized spent hydrogenation catalyst (pore volume 0.46 mL / g, specific surface area 131 m²). 2 / g (with a maximum pore size of 10nm), the filtrate after filtration is used as washing waste liquid, from which metal can be extracted. 50g of the washed and demetallized waste hydrogenation catalyst is weighed, impregnated with a solution containing 3.8g of magnesium nitrate for 1 hour, dried at 120℃ for 3 hours, and then calcined at 300℃ for 3 hours to obtain magnesium oxide-modified waste hydrogenation catalyst. 50g of the magnesium oxide-modified waste hydrogenation catalyst is weighed, impregnated with an aqueous solution containing 12.5g of potassium carbonate for 1 hour, dried at 120℃ for 3 hours, and then calcined at 200℃ for 3 hours to obtain carbon dioxide solid absorbent X-1.

[0050] Example 2

[0051] Weigh 100g of waste oil hydrogenation catalyst (the amount of Fe, Ca, Ni, V and other metals deposited on the alumina support during the hydrogenation process is 28.3wt%, the pore volume is 0.14mL / g, and the specific surface area is 60m²). 2The raw spent hydrogenation catalyst (with a pore size of 8 nm and a corresponding active metal component of 10 wt% MoO3 and 1 wt% NiO) was used as the initial spent hydrogenation catalyst. It was calcined in air using a programmed temperature rise process: from room temperature to 200 °C, held for 2 hours, then to 400 °C, held for 2 hours, and finally to 650 °C, held for 3 hours, yielding the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. An oxalic acid aqueous solution (10 wt%) was used as the washing solution to impregnate the calcined, decarburized, and pore-expanded spent hydrogenation catalyst at room temperature for 3 hours. The amount of washing solution used was 400 parts by weight per 100 parts by weight of the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. The filtered residue was dried at 120 °C to obtain the washed and demetallized spent hydrogenation catalyst (pore volume 0.60 mL / g, specific surface area 162 m²). 2 / g, with a maximum pore size of 11nm), the filtrate after filtration is used as washing waste liquid, from which metal can be extracted. 50g of the washed and demetallized waste hydrogenation catalyst is weighed, impregnated with a solution containing 13.8g of magnesium nitrate for 1 hour, dried at 120℃ for 3 hours, and calcined at 300℃ for 3 hours to obtain magnesium oxide-modified waste hydrogenation catalyst. 50g of the magnesium oxide-modified waste hydrogenation catalyst is weighed, impregnated with an aqueous solution containing 8.8g of potassium carbonate for 1 hour, dried at 120℃ for 3 hours, and calcined at 200℃ for 3 hours to obtain carbon dioxide solid absorbent X-2.

[0052] Example 3

[0053] Weigh 100g of waste oil hydrogenation catalyst (the amount of Fe, Ca, Ni, V and other metals deposited on the alumina support during the hydrogenation process is 51.4wt%, the pore volume is 0.08mL / g, and the specific surface area is 30m²). 2 The most probable pore size is 4 nm, and the corresponding fresh catalyst contains 8 wt% MoO3 and 0.6 wt% NiO as the original spent hydrogenation catalyst. It was calcined in air using a programmed temperature rise process: from room temperature to 200°C, held for 2 hours, then to 400°C, held for 2 hours, and finally to 750°C, held for 3 hours, to obtain the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. A 15 wt% sodium hydroxide aqueous solution was used as the washing solution to impregnate and wash the calcined, decarburized, and pore-expanded spent hydrogenation catalyst at room temperature for 2 hours. The amount of washing solution used was 300 parts by weight per 100 parts by weight of the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. The filtered residue was dried at 120°C to obtain the washed and demetallized spent hydrogenation catalyst (pore volume 0.43 mL / g, specific surface area 108 m²). 2 / g (with a maximum pore size of 10nm), the filtrate after filtration is used as washing waste liquid, from which metal can be extracted. 50g of the washed and demetallized waste hydrogenation catalyst is weighed, impregnated with a solution containing 9.7g of magnesium nitrate for 1 hour, dried at 120℃ for 3 hours, and then calcined at 300℃ for 3 hours to obtain magnesium oxide-modified waste hydrogenation catalyst. 50g of the magnesium oxide-modified waste hydrogenation catalyst is weighed, impregnated with an aqueous solution containing 16.7g of potassium carbonate for 1 hour, dried at 120℃ for 3 hours, and then calcined at 200℃ for 3 hours to obtain carbon dioxide solid absorbent X-3.

[0054] Example 4

[0055] Weigh 100g of waste oil hydrogenation catalyst (the amount of Fe, Ca, Ni, V and other metals deposited on the alumina support during the hydrogenation process is 43.9wt%, the pore volume is 0.11mL / g, and the specific surface area is 44m²). 2 The raw spent hydrogenation catalyst (with a pore size of 6 nm and a corresponding active metal component of 8 wt% MoO3 and 2 wt% NiO) was used as the initial spent hydrogenation catalyst. It was calcined in air using a programmed temperature increase: from room temperature to 150 °C, held for 2 hours, then to 350 °C, held for 2 hours, and finally to 600 °C, held for 3 hours, yielding the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. A 20 wt% citric acid aqueous solution was used as the washing solution to impregnate and wash the calcined, decarburized, and pore-expanded spent hydrogenation catalyst at room temperature for 6 hours. The washing solution was used in a volume of 500 parts by weight per 100 parts by weight of the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. The filtered residue was dried at 120 °C to obtain the washed and demetallized spent hydrogenation catalyst (pore volume 0.68 mL / g, specific surface area 210 m²). 2 / g (most probable pore size 12nm), the filtrate after filtration is used as washing waste liquid, from which metal can be extracted. 50g of the washed and demetallized waste hydrogenation catalyst is weighed, impregnated with a solution containing 3.8g magnesium nitrate for 1 hour, dried at 120℃ for 3 hours, and then calcined at 300℃ for 3 hours to obtain magnesium oxide-modified waste hydrogenation catalyst. 50g of the magnesium oxide-modified waste hydrogenation catalyst is weighed, impregnated with an aqueous solution containing 12.5g potassium carbonate for 1 hour, dried at 120℃ for 3 hours, and then calcined at 200℃ for 3 hours to obtain carbon dioxide solid absorbent X-4.

[0056] Comparative Example 1

[0057] Weigh 100g of waste oil hydrogenation catalyst (the amount of Fe, Ca, Ni, V and other metals deposited on the alumina support during the hydrogenation process is 43.9wt%, the pore volume is 0.11mL / g, and the specific surface area is 44m²). 2The raw spent hydrogenation catalyst (with a pore size of 6 nm and a corresponding active metal component of 8 wt% MoO3 and 2 wt% NiO) was used as the initial spent hydrogenation catalyst. It was calcined in air using a programmed temperature rise process: from room temperature to 150 °C, held for 2 hours, then to 350 °C, held for 2 hours, and finally to 600 °C, held for 3 hours, yielding the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. A 20 wt% citric acid aqueous solution was used as the washing solution to impregnate the calcined, decarburized, and pore-expanded spent hydrogenation catalyst at room temperature for 2 hours. The amount of washing solution used was 500 parts by weight per 100 parts by weight of the calcined, decarburized, and pore-expanded spent hydrogenation catalyst. The filtered residue was dried at 120 °C to obtain the washed and demetallized spent hydrogenation catalyst (pore volume 0.46 mL / g, specific surface area 131 m²). 2 / g, with a maximum pore size of 10nm), the filtrate after filtration is used as washing waste liquid, from which metal can be extracted. Weigh 50g of the waste hydrogenation catalyst after washing and demetallization, soak it in an aqueous solution containing 12.5g of potassium carbonate for 1 hour, dry it at 120℃ for 3 hours, and calcine it at 200℃ for 3 hours to obtain carbon dioxide solid absorbent DX-1.

[0058] Comparative Example 2

[0059] 50g of fresh industrial alumina carrier (free from metals deposited during hydrogenation and hydrogenation-active metal components) was weighed and impregnated in a solution containing 3.8g of magnesium nitrate for 1 hour. After drying at 120℃ for 3 hours, it was calcined at 300℃ for 3 hours to obtain magnesium oxide-modified alumina carrier. Another 50g of magnesium oxide-modified alumina carrier was weighed and impregnated in an aqueous solution containing 12.5g of potassium carbonate for 1 hour. After drying at 120℃ for 3 hours, it was calcined at 200℃ for 3 hours to obtain carbon dioxide solid absorbent DX-2.

[0060] Comparative Example 3

[0061] 50g of fresh residue hydrotreating catalyst (containing only the active hydrogenation metal components, including 8wt% MoO3 and 2wt% NiO, excluding metals deposited during hydrotreating) was weighed and impregnated in a solution containing 3.8g of magnesium nitrate for 1 hour. After drying at 120℃ for 3 hours, it was calcined at 300℃ for 3 hours to obtain a magnesium oxide-modified residue hydrotreating catalyst. Another 50g of the magnesium oxide-modified residue hydrotreating catalyst was weighed and impregnated in an aqueous solution containing 12.5g of potassium carbonate for 1 hour. After drying at 120℃ for 3 hours, it was calcined at 200℃ for 3 hours to obtain carbon dioxide solid absorbent DX-3.

[0062] Comparative Example 4

[0063] Weigh 50g of alumina carrier (which does not contain metal deposited during hydrogenation or hydrogenation active metal components), immerse it in an aqueous solution containing 12.5g of potassium carbonate for 1 hour, dry it at 120℃ for 3 hours, and calcine it at 200℃ for 3 hours to obtain carbon dioxide solid absorbent DX-4.

[0064] Comparative Example 5

[0065] Weigh 50g of fresh residue oil hydrogenation catalyst (containing no metal deposited during hydrogenation, but only the active metal components for hydrogenation, including 8wt% MoO3 and 2wt% NiO), impregnate it in an aqueous solution containing 12.5g potassium carbonate for 1 hour, dry it at 120℃ for 3 hours, and calcine it at 200℃ for 3 hours to obtain carbon dioxide solid absorbent DX-5.

[0066] Comparative Example 6

[0067] Weigh 100g of waste oil hydrogenation catalyst (the amount of Fe, Ca, Ni, V and other metals deposited on the alumina support during the hydrogenation process is 43.9wt%, the pore volume is 0.11mL / g, and the specific surface area is 44m²). 2 The waste hydrogenation catalyst (with a pore volume of 0.10 mL / g and a pore size of 6 nm, corresponding to a hydrogenation active metal component of 8 wt% MoO3 and 2 wt% NiO) was used as the raw waste hydrogenation catalyst. It was calcined in air using a programmed temperature rise process: from room temperature to 150 °C, held for 2 hours, then further increased to 350 °C, held for 2 hours, and finally increased to 600 °C, held for 3 hours. This yielded the calcined, decarburized, and pore-expanded waste hydrogenation catalyst (pore volume 0.10 mL / g, specific surface area 22 m²). 2 / g, with a maximum pore size of 8nm). Take 50g of the calcined, decarburized, and pore-expanded waste hydrogenation catalyst, impregnate it in a solution containing 3.8g of magnesium nitrate for 1 hour, dry it at 120℃ for 3 hours, and then calcine it at 300℃ for 3 hours to obtain magnesium oxide-modified waste hydrogenation catalyst. Weigh 50g of the magnesium oxide-modified waste hydrogenation catalyst, impregnate it in an aqueous solution containing 12.5g of potassium carbonate for 1 hour, dry it at 120℃ for 3 hours, and then calcine it at 200℃ for 3 hours to obtain carbon dioxide solid absorbent DX-6.

[0068] Test Example 1

[0069] The method described in the reference (Energy Fuels 2011, 25, 5528-5537) was modified. CO2 adsorption was measured using a chemisorption analyzer. The solid adsorbent was saturated with water vapor at room temperature (more than 24 h). Then, 0.2 g of the solid adsorbent was weighed into a U-shaped quartz tube, installed in a heating furnace, and pretreated under an Ar atmosphere. Then, a CO2 / Ar mixed gas was introduced at 50 °C to allow the solid adsorbent to adsorb CO2 until saturation. Then, the atmosphere was switched to Ar to purge for 20 min. Then, the temperature was programmed to increase from 50 °C to 500 °C at a rate of 10 °C / min. At the same time, the desorbed CO2 signal was collected by mass spectrometry. Following the above method, the weak CO2 adsorption capacity, strong CO2 adsorption capacity, and total CO2 adsorption capacity of the carbon dioxide solid absorbents of Examples 1-3 and Comparative Examples 1-5 were determined. The amount of CO2 desorbed at 100-250℃ (KHCO3 decomposition temperature) was defined as the weak CO2 adsorption capacity, and the amount of CO2 desorbed at 250-350℃ (KAlCO3(OH)2 decomposition temperature) was defined as the strong CO2 adsorption capacity. The sum of these two values ​​was the total CO2 adsorption capacity. The results are shown in Table 1.

[0070] As can be seen from the results in Table 1, when the content of active ingredient K2CO3 is the same, the CO2 adsorption capacity (especially the strong CO2 adsorption capacity) of the CO2 absorbing material provided by the present invention is significantly higher than that of the comparative example.

[0071] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0072] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0073] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

[0074] Table 1

[0075]

Claims

1. A method for preparing a carbon dioxide absorbent using spent hydrogenation catalyst, characterized in that, The method includes: The original waste hydrogenation catalyst is subjected to calcination, decarburization and pore-expansion treatment to obtain the calcined, decarburized and pore-expansion waste hydrogenation catalyst; the original waste hydrogenation catalyst includes an alumina support and a metal component, the metal component includes a hydrogenation active metal component supported on a fresh hydrogenation catalyst and metal impurities deposited on the alumina support during hydrogenation. The calcined, decarburized, and pore-expanded waste hydrogenation catalyst was washed and demetallized to obtain the washed and demetallized waste hydrogenation catalyst. The waste hydrogenation catalyst after washing and demetallization is modified with alkaline earth metal oxides to obtain the waste hydrogenation catalyst modified with alkaline earth metal oxides. The waste hydrogenation catalyst modified with alkaline earth metal oxides was subjected to alkali metal carbonate loading treatment to obtain alkali metal carbonate-loaded waste hydrogenation catalyst.

2. The method according to claim 1, wherein, Based on the total amount of the original waste hydrogenation catalyst, the content of metal impurities deposited on the alumina support during the hydrogenation process is 20-80 wt%. The metallic impurities deposited on the alumina support during the hydrogenation process include at least one of nickel, vanadium, calcium, and iron. The original spent hydrogenation catalyst has a pore volume of 0.02-0.8 mL / g and a specific surface area of ​​10-200 m². 2 / g, with most probable pore sizes of 1-15nm; The sources of the original waste hydrogenation catalyst include at least one of waste gasoline hydrogenation catalyst, waste diesel hydrogenation catalyst, waste coal tar hydrogenation catalyst, waste wax oil hydrogenation catalyst, and waste residue oil hydrogenation catalyst.

3. The method according to claim 2, wherein, Based on the total amount of the original waste hydrogenation catalyst, the content of metal impurities deposited on the alumina support during the hydrogenation process is 25-60 wt%. The sources of the original waste hydrogenation catalyst include waste residue oil hydrogenation catalyst.

4. The method according to claim 1 or 2, wherein, The roasting, decarburization, and pore-expanding treatment includes: subjecting the original waste hydrogenation catalyst to a first heat treatment, a second heat treatment, and a third heat treatment in an oxygen-containing atmosphere; wherein the oxygen content in the oxygen-containing atmosphere is 8-30% by volume. The conditions for the first heat treatment include: a temperature of 100-250℃ and a time of 1-5 hours; The conditions for the second heat treatment include: a temperature of 300-450℃ and a time of 1-5 hours; The conditions for the third heat treatment include: a temperature of 500-800℃ and a time of 1-5 hours.

5. The method according to claim 4, wherein, In the oxygen-containing atmosphere, the volume content of oxygen is 10-25%; The conditions for the first heat treatment include: treatment at a temperature of 150-200℃ for 1-3 hours; The conditions for the second heat treatment include: treatment at a temperature of 350-420°C for 1-3 hours; The conditions for the third heat treatment include: treatment at a temperature of 600-750℃ for 1-3 hours.

6. The method according to claim 1, wherein, The washing and demetallization process includes: contacting the calcined, decarburized, and pore-expanded waste hydrogenation catalyst with a washing solution for washing, followed by solid-liquid separation to obtain washing waste liquid and the washed and demetallized waste hydrogenation catalyst; the washing solution is an acid solution or an alkaline solution. The content of the metal impurities in the original waste hydrogenation catalyst is 1.5-5 times that in the waste catalyst after washing and demetallization treatment; The concentration of acid in the acid solution is 10-98 wt%; the concentration of alkali in the alkaline solution is 10-60 wt%. The amount of the washing solution used is 200-1000 parts by weight relative to 100 parts by weight of the spent hydrogenation catalyst after calcination, decarburization and pore expansion. The acid is at least one of sulfuric acid, nitric acid, hydrochloric acid, oxalic acid, citric acid, and tartaric acid; The alkali is at least one selected from ammonia monohydrate, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; The washing conditions include: a temperature of 1-100℃ and a time of 0.5-10 hours; The pore volume of the washed and demetallized spent hydrogenation catalyst is 0.2-1.0 mL / g, and the specific surface area is 50-300 m² / g. 2 / g, with a most probable pore size of 5-15nm and a carbon content of less than 3% by weight.

7. The method according to claim 6, wherein, The content of the metal impurities in the original waste hydrogenation catalyst is 2-3 times that in the waste catalyst after washing and demetallization treatment; The washing conditions include: a temperature of 1-100℃ and a time of 1-5 hours; The pore volume of the washed and demetallized spent hydrogenation catalyst is 0.3-0.8 mL / g, and the specific surface area is 100-200 m² / g. 2 / g, with a most probable pore size of 8-12nm and a carbon content of less than 1% by weight.

8. The method according to claim 7, wherein, The content of the metal impurities in the spent hydrogenation catalyst after washing and demetallization is 2-30 wt%.

9. The method according to claim 8, wherein, The content of the metal impurities in the spent hydrogenation catalyst after washing and demetallization is 6-25 wt%.

10. The method according to any one of claims 6-9, wherein, The method also includes: extracting metals from the washing waste liquid.

11. The method according to claim 1, wherein, The alkaline earth metal oxide modification process includes: first impregnating the washed and demetallized waste hydrogenation catalyst with a first impregnation solution containing alkaline earth metal elements and then performing solid-liquid separation to obtain the first impregnated waste hydrogenation catalyst. The first impregnated waste hydrogenation catalyst is subjected to a first drying and a first calcination to obtain a waste hydrogenation catalyst modified with alkaline earth metal oxides. The amount of the alkaline earth metal element, calculated as oxide, is 0.5-10 parts by weight relative to 100 parts by weight of the spent hydrogenation catalyst after washing and demetallization. The first impregnation is an equal-volume saturated impregnation, an unsaturated impregnation, or a supersaturated impregnation; The conditions for the first drying include: a temperature of 80-150℃ and a time of 2-8 hours; The conditions for the first roasting include: a temperature of 200-600℃ and a time of 2-8 hours; The first impregnation solution contains at least one of magnesium nitrate, beryllium nitrate, calcium nitrate, strontium nitrate, and barium nitrate.

12. The method according to claim 11, wherein, The amount of the alkaline earth metal element, calculated as oxide, is 1-8 parts by weight relative to 100 parts by weight of the spent hydrogenation catalyst after washing and demetallization.

13. The method according to claim 1, wherein, The operation of the alkali metal carbonate loading treatment includes: using the waste hydrogenation catalyst modified by the alkaline earth metal oxide as a support and subjecting it to a second impregnation with a second impregnation liquid containing active ingredients, followed by solid-liquid separation to obtain the second impregnated support, wherein the active ingredients are alkali metal carbonates and / or alkali metal bicarbonates. The second impregnated carrier is subjected to a second drying and a second calcination to obtain the second calcined material; The amount of the active ingredient is 10-40 parts by weight relative to every 100 parts by weight of the carrier; Each of the second impregnations is independently an equal-volume saturated impregnation, an unsaturated impregnation, or a supersaturated impregnation; The conditions for the second drying include: a temperature of 80-120°C and a time of 2-8 hours; The conditions for the second roasting include: a temperature of 120-200℃ and a time of 2-8 hours.

14. The method according to claim 13, wherein, The amount of the active ingredient is 20-30 parts by weight relative to every 100 parts by weight of the carrier.

15. The carbon dioxide absorbent obtained by the method of any one of claims 6-14.

16. The use of the carbon dioxide absorbent according to any one of claims 1-5 and 15 in absorbing carbon dioxide and / or reducing carbon dioxide emissions.

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