CN110465267B

CN110465267B - Method for preparing nitrogen-sulfur-rich porous adsorbent material from oil sand asphaltene and application

Info

Publication number: CN110465267B
Application number: CN201910607889.2A
Authority: CN
Inventors: 何林; 孔顺利; 李鑫钢; 隋红
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2019-07-08
Filing date: 2019-07-08
Publication date: 2022-08-19
Anticipated expiration: 2039-07-08
Also published as: CN110465267A

Abstract

The invention provides a method for preparing a porous adsorbent material rich in nitrogen and sulfur by using oil sand asphaltene as a raw material and application thereof. Mixing the prepared adsorbent with the dye waste liquid, adsorbing the dye, and purifying the waste water. The adsorbent has good adsorption capacity due to the abundant pores and the high content of nitrogen and sulfur atoms, and meanwhile, the treatment process has the characteristics of high speed, high capacity and the like. The porous adsorbent material provided by the invention has rich microporous structures, has the advantages of high adsorption rate, good adsorption capacity, capability of promoting adsorption of nitrogen and sulfur functional groups, reusability and the like, and is simple in preparation process.

Description

Method for preparing nitrogen-sulfur-rich porous adsorbent material from oil sand asphaltene and application

Technical Field

The invention belongs to the technical field of material preparation, relates to an extraction and application technology of oil sand asphaltene, and particularly relates to a method for preparing a porous adsorbent material rich in nitrogen and sulfur by using the oil sand asphaltene as a raw material and application of the porous adsorbent material.

Background

Oil sand is an unconventional petroleum resource, and because the oil sand is abundant in reserves, the oil sand accounts for about 30% of the world petroleum resources, and thus the oil sand is concerned by researchers as an alternative and supplementary energy source. Oil sands, also known as heavy oil sands, bituminous sands, or tar sands, are composed of a mixture of inorganic matter (gravel, clay, minerals, 70% -90%), heavy bitumen oil (4% -20%), and water (1% -6%). Unconventional resources such as oil sands lack particularly strict definitions, but have similar characteristics, namely compactness, viscosity, chemical complexity and high carbon to hydrogen ratio. Of the existing reserves, which have been identified primarily in north america, eastern europe, latin america, etc., the reserves exceed 6 trillion barrels of recoverable oil, accounting for about 70% of the world's oil reserves, with 1.7 trillion barrels of heavy bitumen oil in canadian oil sands alone. The non-conventional fossil resources which become the main part of the liquid fossil resources can become the future energy guarantee.

However, in the actual utilization process, because the oil sand asphalt belongs to heavy oil and has high asphaltene content, the problems of precipitation, blockage and the like can be caused in transportation and production in the petroleum industry. Asphaltenes are a complex mixture of aromatic molecules, widely found in crude oil, petroleum residues, coal processing, and are generally defined by solubility characteristics rather than chemical structure. Asphaltenes refer to fractions that are insoluble in low carbon n-alkanes (n-hexane, n-heptane or n-pentane) but soluble in light aromatics (toluene and benzene). In general, asphaltenes can be obtained from crude oil or petroleum-based bitumen, oil sand bitumen by means of solvent extraction, wherein the content of asphaltenes also accounts for 6-20% of the total amount of bitumen, and the utilization value is remarkable.

Due to the prominent position of oil sands, research on oil sand separation and resource utilization is a subject of controversial research in recent years, and separation of different oil sands has characteristics of the oil sands. The hot alkali water washing separation technology is mainly used for oil sand with water wettability, water is mixed with the oil sand, and air blowing is carried out to increase the contact area so as to peel off asphalt to realize separation and utilization. The water washing separation technology is the earliest and most mature technology. For oil-wet oil sand, the washing effect is poor, and the pyrolysis and dry distillation technology and the solvent extraction technology have greater advantages. The pyrolysis and dry distillation technology refers to a process of carrying out high-temperature cracking on oil sand in an inert atmosphere to obtain gaseous (non-condensable gas), liquid (pyrolysis oil) and solid products (residual coke), and is high in energy consumption, so that certain raw materials can be broken into short-chain structures to influence development and application of the short-chain structures, but the pyrolysis and dry distillation technology is an effective treatment means for heavy oils. The solvent extraction separation technology mixes an organic solvent with oil sand, utilizes the organic solvent to dissolve and separate the oil sand asphalt with strong solubility, recovers the solvent by means of distillation and the like, greatly eliminates gravel in the oil sand asphalt, improves the quality of asphalt heavy oil, and reduces the utilization and processing difficulty. However, in the use of solvent-extracted asphalts, the presence of asphaltenes can create many potential hazards, and therefore, the asphaltenes are selectively removed and further used.

There are many ways of recycling asphaltenes, including pyrolysis, hydro-gasification, and carbon material synthesis, which have higher added value. In the pyrolysis process, C-C bonds in alkyl chains are broken at high temperature in a nitrogen atmosphere, and polycyclic aromatic hydrocarbon/aromatic compound is subjected to dealkylation side chains and condensation to generate larger molecules, so that the interlayer spacing is reduced, and part of the polycyclic aromatic hydrocarbon/aromatic compound is focused to form coke. Wherein the released short-chain alkanes and compounds form gaseous, liquid pyrolysis products. The process converts the asphaltene into short-chain compounds, which is beneficial to further improving the utilization value of the asphaltene. The hydro-gasification is to further improve the value of the product by utilizing the reaction of a hydrogen donor and the asphaltene under the action of a catalyst on the basis of high temperature. However, the catalyst and the hydrogen donor are expensive, and the catalyst is easy to deactivate due to the existence of the heteroatom, so that the total cost is high. The synthesized carbon material is mainly based on carbon elements in raw materials, and meanwhile, the degree of graphitization of the asphaltene is easily improved, so that the synthesized carbon material is considered to be a promising molecular precursor of the functional carbon material. The porous carbon material, carbon foam, carbon nanosheet, carbon fiber, multifunctional composite or doped carbon material and the like prepared by the method are widely applied to the occasions of electrodes, water purification, gas adsorption and the like, and particularly have made a breakthrough in the treatment direction of VOCs which are noticed in recent years. However, since some short-chain molecules are difficult to utilize and cause resource waste when the carbon material is directly prepared from asphaltenes, it is the best choice to perform pyrolysis first, recover high value-added substances such as pyrolysis oil and pyrolysis gas generated by gasification, and further prepare the carbon material from solid residues as raw materials.

Disclosure of Invention

The invention provides a method for preparing a porous adsorbent material rich in nitrogen and sulfur by using oil sand asphaltene as a raw material and application of the porous adsorbent material. The preparation process is simple, the product is rich in nitrogen and sulfur elements, the adsorption capacity of the product is kept at a high level, the resource utilization rate of the method is high, and three wastes are not generated.

In order to realize the purpose, the invention adopts the technical scheme that:

a method for preparing a porous adsorbent material by using oil sand asphaltene as a raw material,

(1) crushing a solid product formed after the pyrolysis treatment of the asphaltene into powder, uniformly mixing the powder with an activating agent and a binder, and carrying out extrusion forming;

(2) then the molding material is treated at high temperature, and the adsorbent is obtained after washing and drying after cooling;

the obtained adsorbent material is rich in elements such as nitrogen, sulfur, oxygen and the like.

The asphaltene is extracted from unconventional petroleum natural asphalt such as oil sand. The oil sands are derived from one or more regions in indonesia, china, canada.

The pyrolysis treatment is carried out at the temperature of 400-800 ℃ in the inert gas atmosphere, and the constant temperature treatment time is 10-100min after the final temperature is reached.

The activating agent is one or a mixture of more than two of potassium hydroxide, calcium hydroxide, sodium hydroxide, zinc chloride, phosphoric acid and nitric acid, and the adding amount of the activating agent is 50-600% of the mass of the pyrolysis solid product.

The binder is one or a mixture of more than two of coal tar, sodium carboxymethyl cellulose, phenolic resin, asphalt oil and sodium silicate, and the mass ratio of the pyrolysis solid product to the binder is 10: 1-30: 1.

The high-temperature treatment is carried out in an inert gas atmosphere at the temperature of 400-1000 ℃, and the constant-temperature treatment time is 10-100min after the final temperature is reached.

The washing is to wash for 1 to 20 hours by adopting 0.1 to 1mol/L acid solution and then wash the solution to be neutral by using water; the acid solution is one or a mixture of more than two of hydrochloric acid solution, sulfuric acid solution and phosphoric acid solution.

The adsorbent contains 2-10 wt% of nitrogen element, 3-10 wt% of sulfur element and 3-6 wt% of oxygen element.

The invention protects the application of the porous adsorbent material mainly comprising micropores in the adsorption of dye wastewater. The dye comprises: acid dyes, cationic dyes, direct dyes, disperse dyes, azo dyes, reactive dyes, sulfur dyes, vat dyes, paints, and the like.

The oil sand asphaltene is used as a raw material to prepare the porous adsorbent material, and gaseous and liquid products obtained by pyrolysis can be separated and utilized in the process of pyrolyzing the asphaltene, so that the actual value is improved. Meanwhile, the prepared porous material has large specific surface area and pore volume, and good pore volume and adsorption performance, and is currently applied to a plurality of fields including electromagnetism, capacitance, atmosphere treatment, wastewater treatment and the like.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention uses oil sand asphaltene to prepare the porous adsorbent material rich in nitrogen and sulfur, is mainly used for adsorbing dye wastewater, and has higher adsorption effect.

2. The preparation method is simple and clear, the process preparation is simple, and the adsorbent can be repeatedly used, so that the method has a good application prospect.

3. The preparation method of the invention has high utilization rate of the asphaltene and high utilization value, and does not waste resources and generate three wastes in the whole process.

4. The porous adsorbent material prepared by the invention mainly takes micropores, can quickly realize the adsorption process of dye wastewater, and has better practical value.

Drawings

FIG. 1 is a diagram illustrating the pore size distribution of a porous adsorbent material prepared from asphaltenes provided in example 1 of the present invention;

FIG. 2 is a graph showing the results of adsorption treatment of 0.1g of the porous material prepared in example 1 of the present invention on 200ml of methylene blue solutions (100, 200, 300, 400, 500mg/L) having different initial concentrations;

FIG. 3 is a graph showing the elemental content of a porous adsorbent material prepared from the starting material asphaltenes according to example 1 of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to specific embodiments and drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

The invention provides a method for preparing a porous adsorbent by using oil sand asphaltene as a raw material through pyrolysis. Wherein the pyrolysis process of the asphaltene is converted into gas-liquid-solid products at high temperature in an inert atmosphere. Separating and utilizing gas and liquid products; fully mixing the solid product coke with a powdery activating agent, reacting at high temperature, and forming a hole; and washing and drying the product after the reaction by using a washing solution to prepare the porous material. The adsorbent has the advantages of high adsorption capacity, high adsorption rate and reusability.

The method for preparing the porous adsorbent material by using the oil sand asphaltene as the raw material comprises the following steps of:

(1) removing gravel and three components (saturated component, aromatic component and colloid) from oil sand by a solvent method, and extracting asphaltene to be used as pretreatment;

(2) pyrolyzing the asphaltene, and respectively utilizing gas, liquid and solid products;

(3) crushing and sieving the solid residue, uniformly mixing the solid residue with the powdered activating agent, the powdered binder and water, and performing extrusion forming under certain pressure;

(4) treating the formed material at a certain high temperature, reacting, cooling, washing by using a solution, and drying to obtain the adsorbent.

As an alternative embodiment of the present invention, the oil sands are derived from, but not limited to, indonesia;

as an alternative embodiment of the invention, the pyrolysis treatment is carried out at a temperature of typically but not exclusively 500 ℃ and after reaching the final temperature, the isothermal treatment is carried out for a time of typically but not exclusively 60 min.

As an alternative embodiment of the invention, the type of activator is typically, but not limited to: the mass ratio of the added amount of the potassium hydroxide and the activating agent to the pyrolysis solid product is typically but not limited to 1:1, 2:1, 3:1, 4: 1.

As an alternative embodiment of the invention, the forming process requires the action of a binder. The binder is typically, but not limited to, bitumen oil, and the pyrolysis solid product to binder mass ratio is typically, but not limited to, 30: 1.

As an alternative embodiment of the invention, the high-temperature treatment adopted in the activation process of the porous material is typically but not limited to 700, 800 and 900 ℃, and after the final temperature is reached, the constant-temperature treatment time is typically but not limited to 30 min.

As an alternative embodiment of the invention, the washing acid solution is typically but not limited to hydrochloric acid solution, the concentration is typically but not limited to 1mol/L, and the mass ratio of the acid solution to the prepared sample is typically but not limited to 100: 1. The washing time is typically, but not limited to, 12 h.

Example 1

A method for preparing a porous adsorbent material by using oil sand asphaltene as a raw material comprises the following steps:

10g of oil sand and 100g of toluene are added into a beaker, stirred uniformly and centrifuged to remove gravel. And (3) carrying out rotary evaporation to obtain asphalt oil, adding n-heptane according to the mass ratio of 1:20, and separating to obtain asphaltene. Taking 3g of asphaltene, crushing the asphaltene into fine particles by a mortar, taking a proper amount of asphaltene, putting the asphaltene at the bottom of a porcelain ark, and slowly flattening. Nitrogen gas is introduced at a flow rate of 100ml/min for more than 30min to displace the air inside and ensure the inertia of the atmosphere. Controlling the temperature to rise at 5 ℃/min, and keeping the temperature for 60min after reaching 500 ℃. And respectively collecting the gas-phase product and the liquid-phase product, and performing later separation and utilization. And (3) respectively grinding the pyrolyzed asphaltene coke and the activating agent potassium hydroxide in a mortar, sieving by using a 100-mesh sieve (the particle size is less than 0.15mm), and respectively storing for later use, wherein the operation and storage environment needs to be dried to prevent potassium hydroxide from absorbing water, increasing weight and caking. 1g of coke powder and 3g of activator powder are respectively taken according to the requirements, fully mixed (stirred for more than 30 min), and 0.033g of binder (Indonesia oil sand asphalt oil) is added. And (3) sampling the mixed powder for multiple times, putting the sampled mixed powder into a mould, carrying out extrusion forming under 15MPa, and uniformly placing the formed sample at the bottom of the ark. Slowly placing the ark in the middle of the tube furnace, opening nitrogen to purge for more than 30min, heating to 800 ℃ according to the heating rate of 5 ℃/min, and keeping the constant temperature for 30 min. A1 mol/L hydrochloric acid solution was prepared using a volumetric flask, and after taking out a sample, the sample was mixed with 200ml of the hydrochloric acid solution and stirred magnetically for 12 hours. Standing for 1h, performing suction filtration and neutral water washing until the pH value of the washing water is 7, and putting the washing water into an oven for drying to obtain the porous adsorbent material. Fig. 1 shows the prepared porous adsorption material, and it can be confirmed that the material is a micro-mesoporous material with micropores. FIG. 2 is a graph showing the results of adsorption treatment of 0.1g of the porous material prepared in inventive example 1 on 200ml of methylene blue solutions (100, 200, 300, 400, 500mg/L) having different initial concentrations, and it can be confirmed that the material has the characteristics of high speed and high adsorption capacity. Fig. 3 is an elemental analysis chart of the prepared porous material, and it can be confirmed that the material is rich in nitrogen and sulfur elements, thereby forming adsorption sites and promoting the adsorption process.

Example 2

10g of oil sand and 100g of toluene were added to a beaker, stirred well and centrifuged to remove grit. Rotationally evaporating to obtain asphalt oil, wherein the mass ratio of asphalt oil to asphalt oil is 1:20 adding n-heptane and separating to obtain asphaltene. Taking 3g of asphaltene, crushing the asphaltene into fine particles by a mortar, taking a proper amount of asphaltene, putting the asphaltene at the bottom of a porcelain ark, and slowly flattening. Nitrogen gas is introduced at a flow rate of 100ml/min for more than 30min to displace the air inside and ensure the inertia of the atmosphere. Controlling the temperature to rise at 5 ℃/min, and keeping the temperature for 60min after reaching 500 ℃. And respectively collecting the gas-phase product and the liquid-phase product, and performing later separation and utilization. And (3) respectively grinding the pyrolyzed asphaltene coke and the activating agent potassium hydroxide in a mortar, sieving by using a 100-mesh sieve (the particle size is less than 0.15mm), and respectively storing for later use, wherein the operation and storage environment needs to be dried to prevent potassium hydroxide from absorbing water, increasing weight and caking. 1g of coke powder and 4g of activator powder are respectively taken according to the requirement, fully mixed (stirred for more than 30 min), and 0.033g of binder (Indonesia oil sand asphalt oil) is added. And (3) sampling the mixed powder for multiple times, putting the sampled mixed powder into a mould, carrying out extrusion forming under 15MPa, and uniformly placing the formed sample at the bottom of the ark. Slowly placing the ark in the middle of the tube furnace, opening nitrogen to purge for more than 30min, heating to 850 ℃ according to the heating rate of 5 ℃/min, and keeping the constant temperature for 30 min. A1 mol/L hydrochloric acid solution is prepared by using a volumetric flask, and after taking out a sample, the sample is mixed with 200ml of hydrochloric acid solution and stirred for 12 hours under magnetic force. Standing for 1h, performing suction filtration, washing with neutral water until the pH of the washing water is 7, and drying in an oven to obtain the porous adsorbent material. The porous material is a micro-mesoporous material taking micropores as raw materials, and has the nitrogen content of 5.2%, the sulfur content of 7.5% and the oxygen content of 4%.

Example 3

20g of oil sand and 200g of toluene were added to a beaker, stirred well and centrifuged to remove grit. And (3) rotationally evaporating to obtain asphalt oil, wherein the mass ratio of the asphalt oil to the water is 1:20 adding n-heptane and separating to obtain asphaltene. Taking 3g of asphaltene, crushing the asphaltene into fine particles by a mortar, taking a proper amount of asphaltene, putting the asphaltene at the bottom of a porcelain ark, and slowly flattening. Nitrogen gas is introduced at a flow rate of 100ml/min for more than 30min to displace the air inside and ensure the inertia of the atmosphere. Controlling the temperature to rise at 5 ℃/min, and keeping the temperature for 60min after the temperature reaches 600 ℃. And respectively collecting the gas-phase product and the liquid-phase product, and performing later separation and utilization. Grinding the pyrolyzed asphaltene coke and the activating agent potassium hydroxide in a mortar respectively, sieving with a 100-mesh sieve (the particle size is less than 0.15mm), and storing respectively for later use, wherein the operation and the storage environment are required to be dried to prevent potassium hydroxide from absorbing water, increasing weight and caking. 1g of coke powder and 2g of activator powder are respectively taken according to the requirement, fully mixed (stirred for more than 30 min), and 0.033g of binder (Indonesia oil sand asphalt oil) is added. And (3) sampling the mixed powder for multiple times, putting the sampled mixed powder into a mould, carrying out extrusion forming under 15MPa, and uniformly placing the formed sample at the bottom of the ark. Slowly placing the ark in the middle of the tube furnace, opening nitrogen to purge for more than 30min, heating to 800 ℃ according to the heating rate of 5 ℃/min, and keeping the constant temperature for 30 min. A1 mol/L hydrochloric acid solution is prepared by using a volumetric flask, and after taking out a sample, the sample is mixed with 200ml of hydrochloric acid solution and stirred for 12 hours under magnetic force. Standing for 1h, performing suction filtration and neutral water washing until the pH value of the washing water is 7, and putting the washing water into an oven for drying to obtain the porous adsorbent material. The porous material is a micro-mesoporous material with micropores, wherein the nitrogen content is 9.3%, the sulfur content is 9%, and the oxygen content is 5.7%.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A porous adsorbent material rich in nitrogen and sulfur prepared from oil sand asphaltene and used for adsorbing dye wastewater and organic salt solution is characterized in that:

the mass percentage of nitrogen element, sulfur element and oxygen element in the adsorbent material is 2-10%, 3-10% and 3-6%;

the adsorption material is a micro-mesoporous material with micropores as main materials;

the preparation method of the adsorbing material comprises the following steps:

the asphaltene is extracted from the oil sand bitumen;

the pyrolysis treatment is carried out at the temperature of 500 ℃ in the inert gas atmosphere, and the constant temperature treatment time is 60min after the final temperature is reached;

(2) then the molding material is processed at high temperature, washed and dried after being cooled to obtain the adsorbent;

the high-temperature treatment is carried out in an inert gas atmosphere at the temperature of 700-900 ℃, and the constant-temperature treatment time is 30min after the final temperature is reached;

the activating agent is potassium hydroxide, and the mass ratio of the adding amount of the activating agent to the pyrolysis solid product is 1:1 or 2:1 or 3:1 or 4: 1;

the binder is asphalt oil, and the mass ratio of the pyrolysis solid product to the binder is 30: 1;