CN111974340A - Desulfurization adsorbent, preparation method thereof and method for deeply desulfurizing hydrocarbon - Google Patents

Abstract

The invention provides a desulfurization adsorbent, a preparation method thereof, and a method for deep desulfurization of carbon tetraalkane. Based on the weight percentage of 100wt%, the desulfurization adsorbent comprises: 60wt%-85wt% of micro-mesoporous molecular sieve carrier, 2wt%-16wt% copper oxide, 1wt%-18wt% nickel oxide, 0.2wt%-5.0wt% wt% of barium oxide, 0.2wt% to 5.0wt% of calcium oxide. The desulfurization adsorbent of the invention has high adsorption desulfurization activity, strong selectivity and high sulfur capacity; when it is used for deep desulfurization of carbon tetraalkane, it has mild operating conditions, flexible adaptability to carbon tetraalkane raw materials, and desulfurization. efficient.

Description

Desulfurization adsorbent and preparation method thereof and method for deep desulfurization of carbon tetraalkane

technical field

The invention belongs to the technical field of desulfurization adsorbents, and in particular relates to a desulfurization adsorbent and a preparation method thereof and a method for deep desulfurization of carbon tetraalkane.

Background technique

As an important basic organic chemical raw material, isobutene is widely used and its demand is expanding. Isobutane dehydrogenation technology is one of the effective methods to increase the production of isobutene. As one of the raw materials for dehydrogenation, carbon tetraalkane has a complex composition. Due to different sources, production processes and transportation processes, carbon tetraalkanes often contain varying amounts of sulfur-containing compounds, oxygen-containing compounds and nitrogen-containing compounds. Sulfur-containing compounds in many impurities are highly polar, and by-produced isobutane contains impurities such as sulfur dioxide, which will poison and deactivate the downstream C4alkane dehydrogenation catalyst. Therefore, in order to make full and rational utilization of carbon tetraalkane, it must be deeply desulfurized, and the deep desulfurization of carbon tetraalkane has gradually become the key to further processing and utilization of carbon tetraalkane.

At present, there are three main methods for removing sulfides in carbon tetraalkanes: hydrogenation, alkali washing and adsorption. The hydrogenation method requires a proprietary catalyst. Since some sulfides are difficult to hydrogenate, in order to remove them by hydrogenation, deep hydrogenation is required, which results in high energy consumption and poor economy. The alkaline washing method mainly uses alkali as the absorbent. The alkaline washing method has high sulfide removal efficiency and is easy to operate and control. However, there is the problem of post-treatment of waste lye, and it is difficult to achieve the effect of deep sulfide removal by alkaline washing. The adsorption method has simple process, low energy consumption, no corrosion and no pollution, especially when the sulfide content is very low, the purification depth of adsorption is much higher than that of hydrogenation and alkali washing processes, so adsorption is more suitable for the deep removal of raw sulfides .

However, the existing desulfurization adsorbents have low desulfurization efficiency, poor desulfurization accuracy and low sulfur capacity, which cannot satisfy the deep desulfurization of carbon tetraalkanes.

SUMMARY OF THE INVENTION

Based on the problems existing in the prior art, the first object of the present invention is to provide a desulfurization adsorbent, the desulfurization adsorbent uses a stepped molecular sieve containing micropores and mesopores as a carrier, through the doping of barium, calcium and copper, The second object of the present invention is to provide a preparation method of the desulfurization adsorbent; the third object of the present invention is to provide a method for deep desulfurization of carbon tetraalkane by using the desulfurization adsorbent.

The object of the present invention is achieved through the following technical solutions:

In one aspect, the present invention provides a desulfurization adsorbent, calculated as 100 wt % by weight, the desulfurization adsorbent comprises:

In the desulfurization adsorbent of the present invention, by doping barium and calcium elements, the acidity of the carrier surface can be adjusted, thereby improving the dispersion and adhesion of active components copper and nickel on the carrier, inhibiting the loss of active components, and effectively solving the problem of It solves the problem of the decrease of the activity of the adsorbent due to the loss of active components.

In the above-mentioned desulfurization adsorbent, preferably, in a weight percentage of 100wt%, the desulfurization adsorbent comprises:

In the above desulfurization adsorbent, preferably, the micro-mesoporous molecular sieve carrier has a pore size distribution of 1 to 15 nm, a total pore volume of 0.3 to 0.5 ml/g, and a specific surface area of 500 to 550 m ² /g;

The micropore pore size distribution is 1-2nm, and the micropore pore volume accounts for 40%-80% of the total pore volume; the mesopore pore size distribution is 8-15nm, and the mesopore pore volume accounts for 20%-60% of the total pore volume.

The micro-mesoporous molecular sieve carrier of the present invention does not need to add reagents such as dispersant, chelating agent, etc., the preparation cost is greatly reduced, the added pore-enlarging agent is easy to obtain, and the preparation process is easy to popularize. Micro-mesoporous carriers have two advantages, one is that the specific surface area is higher, and the loading of metal active components is relatively uniform; the other is that the mass transfer resistance is small, the diffusion of sulfides during adsorption is faster, and the adsorption effect is better.

On the other hand, the present invention also provides the preparation method of the above-mentioned desulfurization adsorbent, which comprises the following steps:

The soluble barium salt and the soluble calcium salt are mixed and added with water to prepare a first dipping solution, the micro-mesoporous molecular sieve carrier is dipped in the first dipping solution, and after dipping, the carrier is dried and roasted to obtain a barium-calcium modified carrier;

The soluble copper salt and the soluble nickel salt are mixed and added with water to prepare a second impregnating liquid, the carrier modified by barium and calcium is impregnated in the second impregnating liquid, and the desulfurization adsorbent is obtained by drying and roasting after impregnation.

In the preparation method of the present invention, the amounts of soluble barium salt, soluble calcium salt, soluble copper salt, soluble nickel salt, micro-mesoporous molecular sieve carrier and water are appropriately adjusted according to actual operations, so as to meet the requirements of micro-mesopores in the desulfurization adsorbent obtained by final roasting. The contents of molecular sieve carrier, copper oxide, nickel oxide, barium oxide and calcium oxide satisfy the above ratio range.

In the above preparation method, preferably, the soluble barium salt includes barium nitrate and/or barium chloride, etc.; the soluble calcium salt includes calcium nitrate and/or calcium chloride, etc.; the soluble copper salt includes copper nitrate and /or copper chloride, etc.; the soluble nickel salt includes nickel nitrate and/or nickel chloride, etc.

In the above preparation method, preferably, the soluble barium salt, the soluble calcium salt, the soluble copper salt and the soluble nickel salt are all nitrates thereof.

In the above-mentioned preparation method, preferably, the temperature of dipping in the first dipping solution is normal temperature, and the dipping time is 12-20 h; the drying temperature after dipping is 90-140° C., and the drying time is 4-10 h; The calcination temperature is 350～550℃, and the calcination time is 4～9h.

In the above-mentioned preparation method, preferably, the temperature of dipping in the second dipping solution is normal temperature, and the dipping time is 12-20 h; the drying temperature after dipping is 90-140° C., and the drying time is 4-10 h; The calcination temperature is 350～550℃, and the calcination time is 4～9h.

In the above-mentioned preparation method, preferably, the preparation method of the micro-mesoporous molecular sieve carrier comprises:

adding the organic acid and/or inorganic acid to the aluminum sol to obtain an acid solution of the aluminum sol, and then dissolving the pore-enlarging agent in the acidic solution of the aluminum sol to obtain an acid solution of the aluminum sol containing the pore-enlarging agent;

The molecular sieve powder and carboxymethyl cellulose are added to the kneader and mixed uniformly, and then the aluminum sol acid solution containing the pore expander is added to continue to knead uniformly;

After extrusion, molding, drying and roasting, a molecular sieve carrier with a micro-mesoporous structure is obtained.

In the above preparation method, preferably, the mass ratio of the pore-enlarging agent to the aluminum sol is 1:(4-20); in the aluminum sol, the mass content of alumina is 20wt%-25wt%.

In the above preparation method, preferably, the pore-enlarging agent may include polyvinyl alcohol and the like.

The present invention uses polyvinyl alcohol as a pore-enlarging agent, which has good solubility and stability, can make the molecular sieve carrier easier to generate micropore and mesopore structure, and can obtain a micro-mesoporous structure with adjustable pore size distribution, and the pore size distribution range 1 to 15 nm.

In the above preparation method, preferably, the organic acid includes oxalic acid and/or citric acid, etc.; the inorganic acid includes nitric acid and/or hydrochloric acid, etc.

In the above preparation method, preferably, the molecular sieve powder includes one or more of NaY molecular sieve original powder, NaX molecular sieve original powder, ZSM-5 molecular sieve original powder and MCM-41 molecular sieve original powder.

In the above preparation method, preferably, the amount of the organic acid and/or the inorganic acid is 2wt% to 35wt% of the pore expanding agent.

In the above preparation method, preferably, the mass ratio of the molecular sieve powder to the carboxymethyl cellulose is (10-30):1.

In the above preparation method, preferably, the mass ratio of the pore-enlarging agent to the molecular sieve powder is 1:(10-50).

In the above preparation method, preferably, the drying temperature is 90-140°C after extrusion molding, and the drying time is 4-10h; the roasting temperature after drying is 350-550°C, and the roasting time is 4-9h.

In another aspect, the present invention also provides a method for deep desulfurization of carbon tetraalkane, which comprises the following steps:

A fixed-bed reactor is used, and the above-mentioned desulfurization adsorbent is filled in the fixed-bed reactor;

The carbon tetraalkane is passed into the fixed bed reactor for desulfurization treatment to obtain the desulfurized carbon tetraalkane.

In the above-mentioned deep desulfurization method, preferably, in the desulfurization process, the reaction temperature is 0-80° C., the reaction pressure is 0.4-2.5 MPa, and the volume liquid space velocity of carbontetraalkane is 0.2-5.0 h ⁻¹ .

In the above-mentioned deep desulfurization method, preferably, in the desulfurization process, the reaction temperature is 10-70° C., the reaction pressure is 0.6-2.0 MPa, and the volume liquid space velocity of the carbon tetraalkane is 0.5-4.0 h ⁻¹ .

The desulfurization adsorbent of the invention has high adsorption desulfurization activity, strong selectivity and high sulfur capacity; it is used for deep desulfurization of carbon tetraalkane, and has mild operating conditions, flexible adaptability to carbon tetraalkane raw materials, and desulfurization. efficient.

Description of drawings

Fig. 1 is a pore size distribution diagram of the micro-mesoporous molecular sieve carrier prepared in Example 1 of the present invention.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solutions of the present invention are now described in detail below, but should not be construed as limiting the scope of implementation of the present invention.

In the following examples, the isobutane raw material is derived from the isobutane raw material obtained by the separation of the sulfuric acid alkylation unit, and the components are shown in Table 1:

Table 1:

component Content/w% propane 0.58 Isobutane 89.16 n-butane 9.63 C⁵⁺ 0.58

The analytical method uses ultraviolet fluorescence sulfur analyzer to measure the sulfur content of the isobutane raw material obtained by the alkylation unit before and after desulfurization, and the sulfur dioxide content in the isobutane raw material before desulfurization is 280 mg/kg.

Example 1:

The present embodiment provides a preparation method of a desulfurization adsorbent, which comprises the following steps:

Weigh 240g of aluminum sol containing 25% alumina in a beaker, add 5.0g of oxalic acid to it and mix it well, then add it to the aluminum sol to obtain an aluminum sol oxalic acid solution; weigh 15.0g of polyvinyl alcohol pore expander and add into the prepared aluminum sol oxalic acid solution, stirring evenly, to obtain an aluminum sol oxalic acid solution containing a pore-enlarging agent.

300g of NaY molecular sieve original powder and 13g of carboxymethyl cellulose were weighed into the kneader and mixed uniformly, and then the aluminum sol oxalic acid solution containing pore expander was added to continue kneading uniformly.

It was kneaded and extruded into a cylindrical shape, then dried at 110°C for 8 hours and calcined at 550°C for 4 hours to obtain a micro-mesoporous molecular sieve carrier M-1, whose specific surface area and pore size distribution are shown in Table 2. Fig. 1 is a pore size distribution diagram of the micro-mesoporous molecular sieve carrier M-1.

It can be seen from Figure 1 that the micro-mesoporous molecular sieve carrier M-1 prepared in this example has a relatively concentrated pore size distribution between 2 nm and 6-14 nm pore size, indicating that the prepared micro-mesoporous molecular sieve carrier M-1 has a composite ladder. Pore structure.

Weigh 12.63g of barium nitrate and 31.24g of calcium nitrate tetrahydrate and add them to 100ml of distilled water to prepare an auxiliary impregnation solution, then impregnate 360g of micro-mesoporous molecular sieve carrier M-1, soak at room temperature for 20 hours, and dry at 110°C after impregnation. 8h, calcined at 530°C for 3h to obtain 374.8g of barium-calcium modified molecular sieve carrier.

Then weigh 89.98g of copper nitrate trihydrate and 100.91g of nickel nitrate hexahydrate into 200ml of distilled water to form an impregnation solution, then impregnate the above-mentioned barium-calcium modified molecular sieve carrier, impregnate it at room temperature for 20 hours, and then impregnate it at 110°C. After drying for 10h and calcining at 530°C for 3h, 430.37g of desulfurization adsorbent 1 was obtained.

The main composition of the desulfurization adsorbent 1 is: copper oxide 6.88wt%, nickel oxide 6.02wt%, barium oxide 1.72wt%, calcium oxide 1.72wt%, and the micro-mesoporous molecular sieve carrier M-1 is 83.66wt%.

The present embodiment also provides a method for deep desulfurization of carbon tetraalkane, which comprises the following steps:

A 30ml fixed bed reactor is used, and the desulfurization adsorbent 1 is filled in the fixed bed reactor;

Pass the isobutane raw material into the reactor from the bottom of the fixed bed reactor and pass it into the fixed bed reactor for desulfurization treatment, the reactor temperature is 25 ° C, the reaction pressure is 1.0 MPa, and the volume liquid space velocity of the isobutane raw material is 2.0 h ^-1 , analyze the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor, when the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor reaches 1 mg/kg, it is considered that the desulfurization adsorbent penetrates and the experiment is stopped. The breakthrough time of the desulfurization sorbent from the initial reaction time of the desulfurization sorbent to the time when the sulfur mass fraction of the outlet sample is higher than 1 mg/kg. During the breakthrough time, the mass fraction of sulfur element adsorbed on the desulfurization adsorbent is the breakthrough sulfur capacity of the adsorbent. The breakthrough time was 44 hours, and the reaction performance of the desulfurization adsorbent 1 is shown in Table 3.

Example 2:

The present embodiment provides a preparation method of a desulfurization adsorbent, which comprises the following steps:

Weigh 220g of aluminum sol containing 25% alumina in a beaker, add 16.0g of nitric acid with a concentration of 68% to the aluminum sol to obtain an aluminum sol nitric acid solution; weigh 20.0g of polyvinyl alcohol pore expander and add it to the prepared in the aluminum sol nitric acid solution obtained by stirring uniformly to obtain an aluminum sol nitric acid solution containing a pore expanding agent.

300g of NaY molecular sieve original powder and 15g of carboxymethyl cellulose were weighed into the kneader and mixed evenly, and then the aluminum sol nitric acid solution containing the pore expander was added to continue kneading evenly.

It was kneaded and extruded into a cylindrical shape, then dried at 120°C for 8 hours and calcined at 600°C for 4 hours to obtain a micro-mesoporous molecular sieve carrier M-2, whose specific surface area and pore size distribution are shown in Table 2.

Weigh 7.00g of barium nitrate and 31.48g of calcium nitrate tetrahydrate into 100ml of distilled water to prepare an auxiliary impregnation solution, then impregnate 355.00g of micro-mesoporous molecular sieve carrier M-2 for 15 hours at room temperature, and then immerse at 110°C after impregnation. After drying for 10h and calcining at 550℃ for 4h, 366.57g of barium-calcium modified molecular sieve carrier was obtained.

Then weigh 84.99g of copper nitrate trihydrate and 130.71g of nickel nitrate hexahydrate into 200ml of distilled water to form an impregnation solution, then impregnate the above-mentioned barium-calcium modified molecular sieve carrier, impregnate it at room temperature for 20 hours, and then impregnate it at 130°C. After drying for 5 hours and calcining at 500°C for 5 hours, 428.13 g of desulfurization adsorbent 2 were obtained.

The main composition of the desulfurization adsorbent 2 is: copper oxide 6.54wt%, nickel oxide 7.84wt%, barium oxide 0.96wt%, calcium oxide 1.74wt%, and the micro-mesoporous molecular sieve carrier M-2 is 82.92wt%.

The present embodiment also provides a method for deep desulfurization of carbon tetraalkane, which comprises the following steps:

A 30ml fixed-bed reactor is used, and the desulfurization adsorbent 2 is filled in the fixed-bed reactor;

Pass the isobutane raw material into the reactor from the bottom of the fixed bed reactor and pass it into the fixed bed reactor for desulfurization treatment, the reactor temperature is 25 ° C, the reaction pressure is 1.0 MPa, and the volume liquid space velocity of the isobutane raw material is 2.0 h ^-1 , analyze the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor, when the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor reaches 1 mg/kg, it is considered that the desulfurization adsorbent penetrates and the experiment is stopped. The breakthrough time of the desulfurization sorbent from the initial reaction time of the desulfurization sorbent to the time when the sulfur mass fraction of the outlet sample is higher than 1 mg/kg. During the breakthrough time, the mass fraction of sulfur element adsorbed on the desulfurization adsorbent is the breakthrough sulfur capacity of the adsorbent. The breakthrough time is 44 hours, and the reaction performance of desulfurization adsorbent 2 is shown in Table 3.

Example 3:

The present embodiment provides a preparation method of a desulfurization adsorbent, which comprises the following steps:

Weigh 200g of aluminum sol containing 20% alumina in a beaker, add 11.0g of acetic acid to the aluminum sol to obtain an aluminum sol acetic acid solution; weigh 14.0g of polyvinyl alcohol pore expander and add it to the prepared aluminum sol acetic acid solution , stirring uniformly to obtain an aluminum sol acetic acid solution containing a pore-expanding agent.

300g of molecular sieve original powder and 13g of carboxymethyl cellulose were weighed into the kneader and mixed evenly, and then the aluminum sol nitric acid solution containing the pore expander was added to continue kneading evenly.

It was kneaded and extruded into a cylindrical shape, then dried at 120°C for 10 hours, and calcined at 500°C for 4 hours to obtain a micro-mesoporous molecular sieve carrier M-3. Its specific surface area and pore size distribution are shown in Table 2.

Weigh 9.71g of barium nitrate and 64.07g of calcium nitrate tetrahydrate and add them to 150ml of distilled water to prepare an auxiliary impregnation solution, and then impregnate 340.00g of micro-mesoporous molecular sieve carrier M-3 for 18 hours at room temperature. After drying for 6h and calcining at 400°C for 6h, 360.89g of barium-calcium modified molecular sieve carrier was obtained.

Then weigh 109.57g of copper nitrate trihydrate and 88.69g of nickel nitrate hexahydrate into 200ml of distilled water to form an impregnation solution, then impregnate the above-mentioned barium-calcium modified molecular sieve carrier, impregnate it at room temperature for 15h, and then dry it at 130°C. 5h, calcination at 380°C for 9h to obtain 419.75g of desulfurization adsorbent 3.

The desulfurization adsorbent 3 is mainly composed of copper oxide 8.59wt%, nickel oxide 5.43wt%, barium oxide 1.36wt%, calcium oxide 3.62wt%, and the micro-mesoporous molecular sieve carrier M-3 is 81wt%.

The present embodiment also provides a method for deep desulfurization of carbon tetraalkane, which comprises the following steps:

A 30ml fixed-bed reactor is used, and the desulfurization adsorbent 3 is filled in the fixed-bed reactor;

Pass the isobutane raw material into the reactor from the bottom of the fixed bed reactor and pass it into the fixed bed reactor for desulfurization treatment, the reactor temperature is 25 ° C, the reaction pressure is 1.0 MPa, and the volume liquid space velocity of the isobutane raw material is 2.0 h ^-1 , analyze the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor, when the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor reaches 1 mg/kg, the desulfurization adsorbent is considered to have penetrated and the experiment is stopped. The breakthrough time of the desulfurization sorbent from the initial reaction time of the desulfurization sorbent to the time when the sulfur mass fraction of the outlet sample is higher than 1 mg/kg. During the breakthrough time, the mass fraction of sulfur element adsorbed on the desulfurization adsorbent is the breakthrough sulfur capacity of the adsorbent. The breakthrough time is 42 hours, and the reaction performance of desulfurization adsorbent 3 is shown in Table 3.

Example 4:

The present embodiment provides a preparation method of a desulfurization adsorbent, which comprises the following steps:

Weigh 200g of aluminum sol containing 20% alumina in a beaker, add 16.0g of nitric acid with a concentration of 68% to the aluminum sol to obtain an aluminum sol nitric acid solution; weigh 20.0g of polyvinyl alcohol pore expander and add it to the prepared in the aluminum sol nitric acid solution obtained by stirring uniformly to obtain an aluminum sol nitric acid solution containing a pore expanding agent.

300g of molecular sieve original powder and 15g of carboxymethyl cellulose were weighed into the kneader and mixed uniformly, and then the aluminum sol nitric acid solution containing pore expanding agent was added to continue kneading uniformly.

It was kneaded and extruded into a cylindrical shape, then dried at 120°C for 8 hours and calcined at 550°C for 4 hours to obtain a micro-mesoporous molecular sieve carrier M-4. Its specific surface area and pore size distribution are shown in Table 2.

Weigh 16.19g of barium nitrate and 24.03g of calcium nitrate tetrahydrate into 100ml of distilled water to prepare an auxiliary impregnation solution, then impregnate 340g of micro-mesoporous molecular sieve carrier M-4, soak at room temperature for 15 hours, and dry at 110 °C after impregnation. 10h, calcination at 3500℃ for 9h, 355.19g of barium-calcium modified molecular sieve carrier was obtained.

Then weigh 138.40g of copper nitrate trihydrate and 73.91g of nickel nitrate hexahydrate into 200ml of distilled water to form an impregnation solution, then impregnate the above-mentioned barium-calcium modified molecular sieve carrier, impregnate it at room temperature for 16h, and then impregnate it at 110°C. After drying for 5 hours and calcining at 380°C for 3 hours, 419.75 g of desulfurization adsorbent 4 was obtained.

The desulfurization adsorbent 4 is mainly composed of: copper oxide 10.86wt%, nickel oxide 4.52wt%, barium oxide 2.26wt%, calcium oxide 1.36wt%, and the micro-mesoporous molecular sieve carrier M-4 is 81wt%.

The present embodiment also provides a method for deep desulfurization of carbon tetraalkane, which comprises the following steps:

A 30ml fixed bed reactor is used, and the desulfurization adsorbent 4 is filled in the fixed bed reactor;

Pass the isobutane raw material into the reactor from the bottom of the fixed bed reactor and pass it into the fixed bed reactor for desulfurization treatment, the reactor temperature is 25 ° C, the reaction pressure is 1.0 MPa, and the volume liquid space velocity of the isobutane raw material is 2.0 h ^-1 , analyze the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor, when the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor reaches 1 mg/kg, it is considered that the desulfurization adsorbent penetrates and the experiment is stopped. The breakthrough time of the desulfurization sorbent from the initial reaction time of the desulfurization sorbent to the time when the sulfur mass fraction of the outlet sample is higher than 1 mg/kg. During the breakthrough time, the mass fraction of sulfur element adsorbed on the desulfurization adsorbent is the breakthrough sulfur capacity of the adsorbent. The breakthrough time was 49 hours, and the reaction performance of the desulfurization adsorbent 4 is shown in Table 3.

Example 5:

The present embodiment provides a preparation method of a desulfurization adsorbent, which comprises the following steps:

Weigh 200g of aluminum sol containing 20% alumina with a beaker, add 8.0g of nitric acid with a concentration of 68% to the aluminum sol to obtain an aluminum sol nitric acid solution; weigh 25.0g of polyvinyl alcohol pore expander and add it to the prepared in the aluminum sol nitric acid solution obtained by stirring uniformly to obtain an aluminum sol nitric acid solution containing a pore expanding agent.

300g of molecular sieve original powder and 15g of carboxymethyl cellulose were weighed into the kneader and mixed uniformly, and then the aluminum sol nitric acid solution containing pore expanding agent was added to continue kneading uniformly.

It was kneaded and extruded into a cylindrical shape, then dried at 120°C for 8 hours and calcined at 550°C for 4 hours to obtain a micro-mesoporous molecular sieve carrier M-5, whose specific surface area and pore size distribution are shown in Table 2.

Weigh 6.73g of barium nitrate and 16.65g of calcium nitrate tetrahydrate and add them to 120ml of distilled water to prepare an auxiliary impregnation solution, then impregnate 340.00g of micro-mesoporous molecular sieve carrier M-5 for 15h at room temperature, and then immerse at 110°C after impregnation. After drying for 8h and calcining at 380°C for 8h, 347.89g of barium-calcium modified molecular sieve carrier was obtained.

Then weigh 191.8g of copper nitrate trihydrate and 92.19g of nickel nitrate hexahydrate into 200ml of distilled water to form an impregnation solution, then impregnate the above-mentioned barium-calcium modified molecular sieve carrier, impregnate it at room temperature for 18h, and then impregnate it at 130°C. After drying for 5 hours and calcining at 480°C for 6 hours, 434.74 g of desulfurization adsorbent 5 were obtained.

The desulfurization adsorbent 5 is mainly composed of copper oxide 14.53wt%, nickel oxide 5.45wt%, barium oxide 0.91wt%, calcium oxide 0.91wt%, and the micro-mesoporous molecular sieve carrier M-5 is 78.2wt%.

The present embodiment also provides a method for deep desulfurization of carbon tetraalkane, which comprises the following steps:

A 30ml fixed-bed reactor is used, and the desulfurization adsorbent 5 is filled in the fixed-bed reactor;

Pass the isobutane raw material into the reactor from the bottom of the fixed bed reactor and pass it into the fixed bed reactor for desulfurization treatment, the reactor temperature is 25 ° C, the reaction pressure is 1.0 MPa, and the volume liquid space velocity of the isobutane raw material is 2.0 h ^-1 , analyze the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor, when the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor reaches 1 mg/kg, it is considered that the desulfurization adsorbent penetrates and the experiment is stopped. The breakthrough time of the desulfurization sorbent from the initial reaction time of the desulfurization sorbent to the time when the sulfur mass fraction of the outlet sample is higher than 1 mg/kg. During the breakthrough time, the mass fraction of sulfur element adsorbed on the desulfurization adsorbent is the breakthrough sulfur capacity of the adsorbent. The breakthrough time is 43 hours, and the reaction performance of the desulfurization adsorbent 5 is shown in Table 3.

Example 6:

The present embodiment provides a preparation method of a desulfurization adsorbent, which comprises the following steps:

Weigh 200g of aluminum sol containing 20% alumina in a beaker, add 12.0g of nitric acid with a concentration of 68% to the aluminum sol to obtain an aluminum sol nitric acid solution; weigh 20.0g of polyvinyl alcohol pore expander and add it to the prepared In the aluminum sol nitric acid solution obtained by stirring uniformly, the aluminum sol nitric acid solution containing the pore expanding agent is obtained.

300g of molecular sieve original powder and 15g of carboxymethyl cellulose were weighed into the kneader and mixed uniformly, and then the aluminum sol nitric acid solution containing pore expanding agent was added to continue kneading uniformly.

It was kneaded and extruded into a cylindrical shape, then dried at 120°C for 8 hours and calcined at 500°C for 4 hours to obtain a micro-mesoporous molecular sieve carrier M-6, whose specific surface area and pore size distribution are shown in Table 2.

Weigh 6.48g of barium nitrate and 64.07g of calcium nitrate tetrahydrate and add them to 150ml of distilled water to prepare an auxiliary impregnation solution, and then impregnate 340.00g of micro-mesoporous molecular sieve carrier M-6 for 16 hours at room temperature. After drying for 10h and calcining at 480°C for 9h, 358.99g of barium-calcium modified molecular sieve carrier was obtained.

Then weigh 46.13g of copper nitrate trihydrate and 177.37g of nickel nitrate hexahydrate into 200ml of distilled water to form an impregnation solution, and then impregnate the above-mentioned barium-calcium modified molecular sieve carrier for 20 hours at room temperature. After drying for 8 hours and calcining at 480°C for 7 hours, 419.75 g of desulfurization adsorbent 6 was obtained.

The desulfurization adsorbent 6 is mainly composed of: copper oxide 3.62wt%, nickel oxide 10.86wt%, barium oxide 0.90wt%, calcium oxide 3.62wt%, and the micro-mesoporous molecular sieve carrier M-6 is 81wt%.

The present embodiment also provides a method for deep desulfurization of carbon tetraalkane, which comprises the following steps:

A 30ml fixed-bed reactor is used, and the desulfurization adsorbent 6 is filled in the fixed-bed reactor;

Pass the isobutane raw material into the reactor from the bottom of the fixed bed reactor and pass it into the fixed bed reactor for desulfurization treatment, the reactor temperature is 25 ° C, the reaction pressure is 1.0 MPa, and the volume liquid space velocity of the isobutane raw material is 2.0 h ^-1 , analyze the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor, when the sulfur content in the isobutane raw material at the outlet of the fixed bed reactor reaches 1 mg/kg, the desulfurization adsorbent is considered to have penetrated and the experiment is stopped. The breakthrough time of the desulfurization sorbent from the initial reaction time of the desulfurization sorbent to the time when the sulfur mass fraction of the outlet sample is higher than 1 mg/kg. During the breakthrough time, the mass fraction of sulfur element adsorbed on the desulfurization adsorbent is the breakthrough sulfur capacity of the adsorbent. The breakthrough time is 46 hours, and the reaction performance of the desulfurization adsorbent 6 is shown in Table 3.

Comparative Example 1:

This comparative example provides a kind of preparation method of desulfurization adsorbent, and it comprises the following steps:

240 g of aluminum sol containing 25% alumina was weighed in a beaker, 14.0 g of oxalic acid was added to the aluminum sol and mixed uniformly, and then added to the aluminum sol to obtain an aluminum sol oxalic acid solution.

300g of NaY molecular sieve original powder and 15g of carboxymethyl cellulose were weighed into the kneader and mixed uniformly, and then the aluminum sol oxalic acid solution was added to continue kneading uniformly.

After kneading and extruding, it is formed into a cylindrical shape. Then, it was dried at 150° C. for 6 hours, and calcined at 600° C. for 5 hours to obtain molecular sieve carrier N-1, whose specific surface area and pore size distribution are shown in Table 2.

Weigh 12.63g of barium nitrate and 31.24g of calcium nitrate tetrahydrate and add them to 100ml of distilled water to prepare an auxiliary impregnation solution, then impregnate 360g of microporous molecular sieve carrier N-1, impregnate at room temperature for 20h, and dry at 110℃ for 8h after impregnation , and calcined at 530°C for 3h to obtain 374.81g of barium-calcium modified molecular sieve carrier.

Then weigh 89.98g of copper nitrate trihydrate and 100.91g of nickel nitrate hexahydrate into 200ml of distilled water to form an impregnation solution, and then impregnate the above-mentioned barium-calcium modified molecular sieve carrier for 20 hours at room temperature. It was dried for 10 hours and calcined at 530°C for 3 hours to obtain desulfurization adsorbent D-1.

The main composition of the desulfurization adsorbent D-1 is: copper oxide 6.88wt%, nickel oxide 6.02wt%, barium oxide 1.72wt%, calcium oxide 1.72wt%, molecular sieve carrier N-1 is 83.66wt%.

The desulfurization experiment of the desulfurization adsorbent D-1 is the same as that of Example 1.

Comparative Example 2:

This comparative example provides a kind of preparation method of desulfurization adsorbent, and it comprises the following steps:

The preparation process of the micro-mesoporous molecular sieve carrier M-1 is the same as that in Example 1.

Weigh 12.63g of barium nitrate and 31.24g of calcium nitrate tetrahydrate and add them to 100ml of distilled water to prepare an auxiliary impregnation solution, then impregnate 360g of micro-mesoporous molecular sieve carrier M-1, soak at room temperature for 20 hours, and dry at 110°C after impregnation. 8h, calcined at 530°C for 3h to obtain 374.81g of barium-calcium modified molecular sieve carrier.

Then weigh 89.98g of copper nitrate trihydrate and add it to 120ml of distilled water to form an impregnation solution, and then impregnate the above-mentioned barium-calcium modified molecular sieve carrier for 20h at room temperature. After calcination for 3h, 404.47g of desulfurization adsorbent D-2 was obtained.

The main composition of the desulfurization adsorbent D-2 is: copper oxide 7.32wt%, barium oxide 1.83wt%, calcium oxide 1.83wt%, and the micro-mesoporous molecular sieve carrier M-1 is 89.02wt%.

The desulfurization experiment of the desulfurization adsorbent D-2 is the same as that of Example 1.

Comparative Example 3:

This comparative example provides a kind of preparation method of desulfurization adsorbent, and it comprises the following steps:

The preparation process of the micro-mesoporous molecular sieve carrier M-1 is the same as that in Example 1.

Weigh 12.63g of barium nitrate and 31.24g of calcium nitrate tetrahydrate and add them to 100ml of distilled water to prepare an auxiliary impregnation solution, then impregnate 360g of micro-mesoporous molecular sieve carrier M-1, soak at room temperature for 20 hours, and dry at 110°C after impregnation. 8h, calcined at 530°C for 3h to obtain 374.81g of barium-calcium modified molecular sieve carrier.

Then weigh 100.91g of nickel nitrate hexahydrate and add it to 200ml of distilled water to form an impregnation solution, then impregnate the above-mentioned barium-calcium modified molecular sieve carrier, impregnate it at room temperature for 20h, and then dry it at 110°C for 10h after impregnation and at 530°C. After calcination for 3h, 400.74g of desulfurization adsorbent D-3 was obtained.

The desulfurization adsorbent D-3 is mainly composed of: nickel oxide 6.47wt%, calcium oxide 1.85wt%, barium oxide 1.85wt%, and the micro-mesoporous molecular sieve carrier M-1 is 89.83wt%.

The desulfurization experiment of the desulfurization adsorbent D-3 is the same as that of Example 1.

The following Table 2 is the specific surface area and pore size distribution of the micro-mesoporous molecular sieve carrier, and Table 3 is the performance evaluation result table of the desulfurization adsorbent.

Table 2:

table 3:

From the characterization data in Table 2, it can be seen that the total pore volume of the adsorbent with the pore-forming agent is significantly increased, and the average pore size of the mesopores is also significantly higher than that of the adsorbent without the pore-forming agent, indicating that the addition of the pore-forming agent can significantly reduce the medium. Pores are introduced into the adsorbent system.

From the experimental data in Table 3, it can be seen that the desulfurization sorbent adding copper, nickel, barium and calcium has a significantly higher desulfurization performance than the desulfurizing sorbent adding three or two metals. The penetration time is longer and the sulfur capacity is higher, and the penetration sulfur capacity of the desulfurization adsorbent can reach more than 4.7%.

Claims (10)

1. A desulfurization adsorbent, in a weight percentage of 100 wt%, the desulfurization adsorbent comprises:

2. The desulfurization adsorbent according to claim 1, wherein, in a weight percentage of 100 wt%, the desulfurization adsorbent comprises:

3. The desulfurization adsorbent according to claim 1 or 2, wherein the micro-mesoporous molecular sieve carrier has a pore size distribution of 1 to 15 nm, a total pore volume of 0.3 to 0.5 ml/g, and a specific surface area of 500 to 550 m ² /g; Among them, the pore size distribution of micropores is 1-2nm, and the pore volume of micropores accounts for 40%-80% of the total pore volume; the pore size distribution of mesopores is 8-15nm, and the pore volume of mesopores accounts for 20%-60% of the total pore volume. 4. the preparation method of the desulfurization adsorbent described in any one of claim 1～3, it comprises the steps: The soluble barium salt and the soluble calcium salt are mixed and added with water to prepare a first dipping solution, the micro-mesoporous molecular sieve carrier is dipped in the first dipping solution, and after dipping, the carrier is dried and roasted to obtain a barium-calcium modified carrier; The soluble copper salt and the soluble nickel salt are mixed and added with water to prepare a second impregnating liquid, the carrier modified by barium and calcium is impregnated in the second impregnating liquid, and the desulfurization adsorbent is obtained by drying and roasting after impregnation. 5. The preparation method according to claim 4, wherein the soluble barium salt comprises barium nitrate and/or barium chloride; the soluble calcium salt comprises calcium nitrate and/or calcium chloride; the soluble copper salt comprises copper nitrate and/or copper chloride; the soluble nickel salt includes nickel nitrate and/or nickel chloride; Preferably, the soluble barium salt, the soluble calcium salt, the soluble copper salt and the soluble nickel salt are all nitrates thereof. 6 . The preparation method according to claim 4 , wherein the temperature of dipping in the first dipping solution is normal temperature, and the dipping time is 12-20 h; the drying temperature after dipping is 90-140° C., and the drying time is 4 h. 7 . ~10h; the roasting temperature after drying is 350 ~ 550 ℃, and the roasting time is 4 ~ 9h; Preferably, the temperature of dipping in the second dipping solution is normal temperature, and the dipping time is 12-20 h; the drying temperature after dipping is 90-140° C., and the drying time is 4-10 h; the roasting temperature after drying is 350-10 h. 550 ℃, calcination time is 4～9h. 7. The preparation method according to claim 4, wherein the preparation method of the micro-mesoporous molecular sieve carrier comprises: adding the organic acid and/or inorganic acid to the aluminum sol to obtain an acid solution of the aluminum sol, and then dissolving the pore-enlarging agent in the acidic solution of the aluminum sol to obtain an acid solution of the aluminum sol containing the pore-enlarging agent; The molecular sieve powder and carboxymethyl cellulose are added to the kneader and mixed uniformly, and then the aluminum sol acid solution containing the pore expander is added to continue to knead uniformly; After extrusion, molding, drying and roasting, a molecular sieve carrier with a micro-mesoporous structure is obtained. 8 . The preparation method according to claim 7 , wherein the mass ratio of the pore-enlarging agent to the aluminum sol is 1:(4-20); in the aluminum sol, the mass content of alumina is 20wt%～20. 25wt%; Preferably, the pore-enlarging agent comprises polyvinyl alcohol; Preferably, the organic acid includes oxalic acid and/or citric acid; the inorganic acid includes nitric acid and/or hydrochloric acid; Preferably, the molecular sieve powder comprises one or more of NaY molecular sieve original powder, NaX molecular sieve original powder, ZSM-5 molecular sieve original powder and MCM-41 molecular sieve original powder; Preferably, the amount of the organic acid and/or inorganic acid is 2wt% to 35wt% of the pore expanding agent; Preferably, the mass ratio of the pore-enlarging agent to the molecular sieve powder is 1: (10-50); Preferably, the mass ratio of the molecular sieve powder to the carboxymethyl cellulose is (10-30): 1; Preferably, the drying temperature after extrusion molding is 90-140°C, and the drying time is 4-10h; the roasting temperature after drying is 350-550°C, and the roasting time is 4-9h. 9. A method for deep desulfurization of carbon tetraalkane, comprising the following steps: A fixed-bed reactor is used, and the fixed-bed reactor is filled with the desulfurization adsorbent according to any one of claims 1 to 3; The carbon tetraalkane is passed into the fixed bed reactor for desulfurization treatment to obtain the desulfurized carbon tetraalkane. 10. The method according to claim 9, wherein, in the desulfurization process, the reaction temperature is 0～80° C., the reaction pressure is 0.4～2.5MPa, and the volume liquid space velocity of carbon tetraalkane is 0.2～5.0h ⁻¹ ; Preferably, in the desulfurization process, the reaction temperature is 10-70° C., the reaction pressure is 0.6-2.0 MPa, and the volume liquid space velocity of the carbontetraalkane is 0.5-4.0 h ⁻¹ .

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