CN101804329A - Adsorbent for gasoline desulfurization, preparation method thereof and method for gasoline desulfurization by using adsorbent - Google Patents

Abstract

The invention belongs to the technical field of fuel oil processing, and discloses an adsorbent for gasoline desulfurization, a preparation method thereof and a method for gasoline desulfurization by using the adsorbent. The adsorbent is cyclodextrin modified by copper element, and the gasoline desulfurization method is to contact the adsorbent with sulfur-containing fuel oil and realize desulfurization by an adsorption method. The adsorption operation can be carried out at normal temperature and normal pressure, the operation cost is low, and the adsorption effect is good.

Description

Adsorbent for gasoline desulfurization, preparation method thereof, and method for gasoline desulfurization using the adsorbent

technical field

The invention belongs to the technical field of fuel oil processing, and relates to an adsorbent for gasoline desulfurization, a preparation method thereof and a method for using the adsorbent to desulfurize gasoline.

Background technique

The rise of research on the low-sulfur treatment of fuel oil in the world is due to the increasingly popular concept of environmental protection, the important position of fuel oil in human life and the disadvantages it currently exposes, and various related issues Environmental regulations are also becoming increasingly stringent, leading to an increasing demand for low-sulfur clean oil products worldwide. The organic sulfur contained in fuel oil (gasoline, diesel and kerosene, etc.) is one of the main factors leading to environmental pollution. It will produce sulfur oxides during the combustion process, which will be discharged into the atmosphere to pollute the environment and also lead to the formation of acid rain. , corrosion of buildings, etc. At the same time, the rise of new energy represented by fuel cells also depends on the use of low-sulfur liquid fuel oil, so countries around the world have formulated strict fuel oil low-sulfur standards to improve the current situation.

The current desulfurization technology uses hydrodesulfurization technology as the main support technology. Although it has a good removal effect on most of the sulfides in fuel oil, it has a poor removal effect on thiophene sulfides. The standard value of sulfur content can only be reached by expanding the reactor by 5 to 10 times, which not only costs more, but also reduces the octane number of fuel oil. Adsorption desulfurization technology has the advantages of mild conditions (normal temperature and pressure), low investment and operating costs, and high desulfurization efficiency, which has attracted the attention of scientists from all over the world, and is committed to the research and development of this desulfurization technology. / A desulfurization technology with zero sulfur content.

Adsorbent is the core technology of adsorption desulfurization process, and the development of new and efficient adsorbent materials has attracted widespread attention. The literature [Ind.Eng.Chem.Res., 2006, 45:7892] reported that CuCl was loaded on SBA-15 as an adsorbent to remove thiophene from simulated fuel oil. The adsorption capacity has been greatly improved.

The literature [Chem.Eng.Sci., 2008, 63:356] reported that CuCl and PdCl ₂ were supported on MCM-41 and SBA-15 to remove sulfides in aviation kerosene, showing good adsorption performance.

The literature [Energy Fuels, 2008, 22:6] reported that the ion-exchange bimetallic adsorbent CuCeY has good performance in the removal of thiophene, benzothiophene, and 4,6-dimethyldibenzothiophene in simulated fuel oil. adsorption desulfurization performance.

Due to the high activity and low price of copper compounds, more active adsorption species are used. The preparation of the adsorbent is generally to introduce the copper compound onto the carrier such as silica, alumina, molecular sieve and activated carbon by loading method. However, compared with the loading method commonly used in the literature, so far, there has been no report on the use of cyclodextrin as a carrier to introduce copper elements through grafting to prepare adsorbents for the removal of thiophene sulfides.

Contents of the invention

The object of the present invention is to provide an adsorbent for removing thiophene sulfides in gasoline. The adsorbent adopts cyclodextrin doped with copper element, which can adsorb and remove sulfide in gasoline under mild conditions.

Another object of the present invention is to provide a method for preparing the above-mentioned adsorbent.

Another object of the present invention is to provide a method for desulfurizing gasoline using the above-mentioned adsorbent.

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

An adsorbent for gasoline desulfurization, the adsorbent is cyclodextrin doped with copper element.

In the adsorbent, the content of copper element is 4.4%-19.4% of the total mass of the adsorbent.

In the adsorbent, the copper element is monovalent copper, and the copper element is connected with the cyclodextrin in a bonded form.

Said adsorbent, wherein the cyclodextrin is α-cyclodextrin, β-cyclodextrin or γ-cyclodextrin.

The preparation method of described adsorbent, the method comprises the following steps:

Add cuprous tert-butoxide and cyclodextrin to an organic solvent, and stir for 0.5-1.5 hours under the protection of an inert atmosphere (Ar, He or N ₂ ) to react, then add an organic solvent to wash until the washing liquid is clear; wash the sample Vacuum dry at 60°C for 2-3 hours to obtain the adsorbent.

The method, wherein the amount of cuprous tert-butoxide is 0.1087-0.2028 parts by weight, the amount of cyclodextrin is 0.1328-0.7102 parts by weight; the organic solvent is benzene or toluene. (Benzene is used as a solvent on the one hand, and as a detergent on the other hand. In the process of cyclodextrin and cuprous tert-butoxide reaction to prepare the adsorbent, tert-butanol will be generated while the adsorbent is obtained, and washing with benzene is to wash away the tert-butanol Butanol. Based on the above considerations, some organic solvents with similar properties such as toluene can also replace benzene.)

The invention relates to a gasoline adsorption desulfurization method, which uses the above-mentioned adsorbent to contact with sulfur-containing gasoline, and uses the adsorption method to realize the desulfurization of gasoline.

In the gasoline adsorption desulfurization method, the conditions for contacting the gasoline with the adsorbent are as follows: the temperature is room temperature to 50°C, preferably room temperature, and the pressure is normal pressure to 0.5 MPa, preferably normal pressure.

In the gasoline adsorption desulfurization method, the temperature is room temperature and the pressure is normal pressure.

The gasoline adsorption desulfurization method, wherein the sulfur-containing gasoline is gasoline containing thiophene sulfides.

The adsorbent does not need to be activated and can be directly used for adsorption after synthesis.

Beneficial effects of the present invention:

The novel desulfurization adsorbent provided by the present invention adopts the cyclodextrin doped with copper element as the adsorbent, and the desulfurization effect is comparatively ideal, and adopts dynamic adsorption to investigate that it has better adsorption effect to simulated gasoline (to thiophene sulfides in gasoline effective adsorption and removal); the adsorption operation can be carried out under mild conditions (such as normal temperature and pressure), and the operating cost is reduced. The innovation of the present invention is mainly reflected in two aspects: one is the innovation on the carrier, that is, cyclodextrin is used as the carrier. The second is the innovation in the preparation method of the adsorbent. The literature generally introduces copper compounds through the "loading" method, and the dispersion degree of copper elements is not high; while the present invention introduces copper compounds through the "grafting" method, which can achieve a high degree of dispersion of copper elements . The "grafting" of copper element on cyclodextrin is a structural expression, and it is a microscopic change in the preparation process, which can be reflected by the method of preparing the adsorbent, that is, the adsorbent prepared by the method of the present invention, the copper element is in the form of A bonded form (covalent bond) is attached to the cyclodextrin, as evidenced by the characterization of the adsorbent. The present application also adopts the loading method (grinding method) to prepare adsorbents CuCl/CD and CuO ^t Bu/CD (Example 4, 5), and uses the grinding method to load CuCl and CuO ^t Bu on β-cyclodextrin. The investigation of adsorption and removal shows that the adsorption effect of the adsorbent prepared by the grafting method is better than that prepared by the typical loading method through the comparison of the adsorption capacity.

The examples describe the desulfurization effects of adsorbents on thiophene sulfides. Because benzothiophene and 4,6-dimethyldibenzothiophene are macromolecular organic sulfides that are difficult to remove, they are more difficult to remove than thiophene. Therefore, although they are all diluted to prepare simulated gasoline with a sulfur content of 500ppm, there is still some gap in desulfurization effect compared with thiophene.

Detailed ways

The following examples will further illustrate the present invention, but the content of the present invention is not limited thereto at all.

Example 1

Mix 0.0955 g of cuprous tert-butoxide and 0.7102 g of β-cyclodextrin in 10 mL of benzene solution, stir for about 1 h under Ar atmosphere at room temperature and normal pressure, and then add benzene to wash until the washing liquid is clear. The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. Adopt HG/T 2960-2000 method to measure (following examples all adopt this method to measure), the monovalent copper element content is 4.7% of adsorbent gross mass in the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3078g adsorbent in the adsorption column, model gasoline enters from the bottom, and pass through the adsorption column at a flow rate of 3mL/h, and use Varian 3800 gas chromatography to measure the sulfur content of the liquid phase product, and the desulfurization amount is 60μmol sulfur/g adsorbent (The desulfurization amount expressed in this application is the adsorption amount when the adsorbent is saturated and adsorbed, the same below).

Example 2

Mix 0.1290 g of cuprous tert-butoxide and 0.4802 g of β-cyclodextrin in 10 mL of benzene solution, stir for about 1 h under Ar atmosphere at room temperature and normal pressure, then add benzene to wash until the washing solution is clear. The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 8.0% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3088g adsorbent to the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 76μmol sulfur/g adsorption agent.

Example 3

Mix 0.1321 g of cuprous tert-butoxide and 0.3274 g of β-cyclodextrin in 10 mL of benzene solution, stir for about 1 h under Ar atmosphere at room temperature and normal pressure, and then add benzene to wash until the washing liquid is clear. The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 13.3% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3064g adsorbent in the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 89μmol sulfur/g adsorption agent.

Example 4

0.0762g of cuprous chloride and 0.3003g of β-cyclodextrin were mixed and fully ground for 15 minutes, and monovalent copper was doped on the cyclodextrin in a supported manner to obtain an adsorbent sample. The content of the synthesized monovalent copper element is 13.1% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3369g adsorbent into the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 34μmol sulfur/g adsorption agent.

Example 5

Mix 0.09 g of cuprous tert-butoxide and 0.3055 g of β-cyclodextrin and grind them thoroughly for 15 minutes, and dope monovalent copper on the cyclodextrin in a supported manner to obtain an adsorbent sample. The content of the synthesized monovalent copper element is 10.6% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.2574g adsorbent to the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 36μmol sulfur/g adsorption agent.

Example 6

Mix 0.1626g of cuprous tert-butoxide and 0.3009g of β-cyclodextrin in 10mL of benzene solution, stir for about 1h under Ar atmosphere at room temperature and normal pressure, then add benzene to wash until the washing solution is clear. The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 14.4% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.2875g adsorbent to the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 76μmol sulfur/g adsorption agent.

Example 7

Mix 0.1433g of cuprous tert-butoxide and 0.1328g of β-cyclodextrin in 10mL of benzene solution, stir for about 1h under Ar atmosphere at room temperature and normal pressure, then add benzene to wash until the washing liquid is clear. The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 19.4% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.2436g adsorbent to the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 70μmol sulfur/g adsorption agent.

Example 8

Mix 0.1319g of cuprous tert-butoxide and 0.3273g of β-cyclodextrin in 10mL of benzene solution, stir for about 1h under _N2 atmosphere at room temperature and normal pressure, then add benzene to wash until the washing liquid is clear . The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 13.3% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3061g adsorbent into the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 87μmol sulfur/g adsorption agent.

Example 9

Mix 0.1317g of cuprous tert-butoxide and 0.3270g of β-cyclodextrin in 10mL of benzene solution, stir for about 1h under He atmosphere at room temperature and normal pressure, then add benzene to wash until the washing liquid is clear. The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 13.3% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3064g adsorbent into the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 88μmol sulfur/g adsorption agent.

Example 10

Mix 0.1320 g of cuprous tert-butoxide and 0.3272 g of α-cyclodextrin in 10 mL of benzene solution, stir for about 1 h under Ar atmosphere at room temperature and normal pressure, then add benzene to wash until the washing liquid is clear. Dry the washed sample in a vacuum oven at 60°C for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 13.3% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3064g adsorbent in the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 80μmol sulfur/g adsorption agent.

Example 11

Mix 0.1322g of cuprous tert-butoxide and 0.3271g of γ-cyclodextrin in 10mL of benzene solution, stir for about 1h under Ar atmosphere at room temperature and normal pressure, then add benzene to wash until the washing solution is clear. The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 13.3% of the total mass of the adsorbent.

Dissolve 5mL of thiophene in 45mL of isooctane, and dilute to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3064g adsorbent in the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 82μmol sulfur/g adsorption agent.

Example 12

Mix 0.2028 g of cuprous tert-butoxide and 0.5060 g of β-cyclodextrin in 10 mL of benzene solution, stir for about 1 h under Ar atmosphere at room temperature and normal pressure, and then add benzene to wash until the washing liquid is clear. Dry the washed sample in a vacuum oven at 60°C for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 13.3% of the total mass of the adsorbent.

Dissolve 0.1603g of benzothiophene in 100mL of isooctane to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.2597g of adsorbent to the adsorption column, model gasoline enters from the bottom, passes through the entire adsorption column at a flow rate of 3mL/h, and uses Varian 3800 gas chromatography to measure the sulfur content of the liquid phase product, and the desulfurization amount is 28μmol sulfur/g adsorption agent.

Example 13

Mix 0.2028 g of cuprous tert-butoxide and 0.5060 g of β-cyclodextrin in 10 mL of benzene solution, stir for about 1 h under Ar atmosphere at room temperature and normal pressure, and then add benzene to wash until the washing liquid is clear. The sample obtained by washing was vacuum-dried at 60° C. for 2.5 hours to obtain the adsorbent sample. The content of the synthesized monovalent copper element is 13.3% of the total mass of the adsorbent.

Dissolve 0.2303g of 4,6-dimethyldibenzothiophene in 100mL of isooctane to prepare simulated gasoline with a sulfur content of 500ppm. Add 0.3088g adsorbent into the adsorption column, model gasoline enters from the bottom, and passes through the entire adsorption column at a flow rate of 3mL/h, and the sulfur content of the liquid phase product is determined by Varian 3800 gas chromatography, and the desulfurization amount is 20μmol sulfur/g adsorption agent.

Claims (10)

1. A sorbent for gasoline desulfurization, characterized in that the sorbent is copper-doped cyclodextrin. 2. The adsorbent according to claim 1, characterized in that the content of the copper element is 4.4% to 19.4% of the total mass of the adsorbent. 3. The adsorbent according to claim 1 or 2, characterized in that the copper element is monovalent copper, and the copper element is connected with the cyclodextrin in a bonded form. 4. The adsorbent according to claim 1, wherein the cyclodextrin is α-cyclodextrin, β-cyclodextrin or γ-cyclodextrin. 5. the preparation method of adsorbent described in claim 1 is characterized in that the method comprises the following steps: Add cuprous tert-butoxide and cyclodextrin to an organic solvent, stir for 0.5-1.5 hours under the protection of an inert atmosphere to react, then add an organic solvent to wash until the washing liquid is clear; dry the washed sample at 60°C for 2-3 hours in vacuum , that is, the adsorbent is obtained. 6. The method according to claim 5, characterized in that the consumption of cuprous tert-butoxide is 0.1087-0.2028 parts by weight, the consumption of cyclodextrin is 0.1328-0.7102 parts by weight; the organic solvent is benzene or toluene. 7. A gasoline adsorption desulfurization method, characterized in that the method adopts the adsorbent as claimed in claim 1 in contact with sulfur-containing gasoline, and utilizes the adsorption method to realize the desulfurization of gasoline. 8. The method according to claim 7, characterized in that the conditions for contacting the gasoline with the adsorbent are: the temperature is from room temperature to 50° C., and the pressure is from normal pressure to 0.5 MPa. 9. The gasoline desulfurization method according to claim 8, characterized in that the temperature is room temperature and the pressure is normal pressure. 10. The gasoline desulfurization method according to claim 7, characterized in that the sulfur-containing gasoline is gasoline containing thiophene sulfides.