CN115216325B - A high-sulfur petroleum coke high-efficiency desulfurization process - Google Patents

Abstract

The invention discloses a high-sulfur petroleum coke high-efficiency desulfurization process, which specifically involves photocatalytic collaboration with microorganisms to desulfurize petroleum coke, and belongs to the field of clean production of petroleum coke. The present invention includes two aspects: photocatalytic oxidation pretreatment of high-sulfur petroleum coke by using iron-doped titanium dioxide photocatalytic film and biological desulfurization of petroleum coke. The specific steps are as follows: (1) Under the irradiation of a mercury lamp, use a photocatalytic film to conduct photocatalytic oxidation pretreatment of petroleum coke water homogenate (liquid-to-solid ratio: 20-30 mL/g) for 8-12 hours; (2) Use desulfurization Bacteria perform biological desulfurization on the pretreated petroleum coke, add 0.5-1g petroleum coke to the desulfurization medium, and culture it at 30°C for 6-16 days; (3) Wash the petroleum coke sample after biological desulfurization with water, and filter it with suction After drying, synergistic desulfurization of petroleum coke is achieved. The invention makes full use of the characteristics of photocatalysis and microbial desulfurization, including mild conditions, low cost, and environmental friendliness. It can also realize the recycling of photocatalysts, and at the same time meets the needs for deep and efficient petroleum coke desulfurization, and has high practical application. value.

Description

A high-sulfur petroleum coke high-efficiency desulfurization process

Technical field

The invention belongs to the field of clean production of petroleum coke, and specifically discloses a high-sulfur petroleum coke high-efficiency desulfurization process.

Background technique

my country's electrolytic aluminum industry is embarking on a healthy development path, and the demand for petroleum coke has also maintained a steady increase. At present, high-quality low-sulfur petroleum coke is in short supply, so many companies have to turn their attention to the high-sulfur petroleum coke market. However, the sulfur in high-sulfur coke often harms the quality of products. The acid gas released during industrial production can also damage production equipment. In addition, the sulfur in petroleum coke is converted into sulfur dioxide and escapes into the air, causing air pollution. , causing natural disasters such as acid rain. Therefore, exploring technical methods for efficient and economical removal of sulfur from petroleum coke is of great significance for expanding the high-sulfur coke market and improving the utilization rate of high-sulfur petroleum coke.

The sulfur in petroleum coke is mainly organic sulfur, accounting for more than 99%. Among them, thiophenes and their derivatives are the most difficult to remove. Current research on petroleum coke desulfurization, especially the removal of thiophenes, mainly includes high-temperature calcination desulfurization, chemical oxidation desulfurization, alkali metal desulfurization and hydrodesulfurization. However, high-temperature desulfurization, alkali metal desulfurization and hydrodesulfurization often consume a lot of energy and require the use of expensive high-temperature-resistant materials, resulting in high desulfurization costs and major safety hazards; chemical oxidation desulfurization can easily destroy petroleum coke. The graphite crystal structure reduces the quality of petroleum coke, and also brings waste liquid that is difficult to handle, causing environmental pollution and equipment corrosion.

In summary, it is necessary to develop a new petroleum coke desulfurization technology that has mild conditions, is green and environmentally friendly, and is not prone to secondary pollution.

Contents of the invention

In order to solve the problems existing in the traditional petroleum coke desulfurization method, the present invention provides a high-sulfur petroleum coke high-efficiency desulfurization process, which utilizes the collaborative desulfurization capabilities of photocatalysis and microorganisms and combines their respective technical advantages in order to obtain efficient and deep desulfurization effects.

In order to achieve the above desulfurization purpose, the present invention provides a high-sulfur petroleum coke high-efficiency desulfurization process. The technical solution is as follows.

Nanoscale titanium dioxide films with an iron content of 1-4 wt% were prepared using the sol-gel method.

Take an appropriate amount of high-sulfur petroleum coke and crush it until the particle size is less than 200 mesh.

Weigh 0.5-1 g of petroleum coke and add it to a petri dish containing 14.5 mL of deionized water. Then add 0.5-1 mL of 30% hydrogen peroxide as an auxiliary oxidant. Stir evenly and add the iron-doped titanium dioxide film.

Place the culture dish flatly in the photocatalytic reactor and irradiate it with a 200-300 W high-pressure mercury lamp for 8-10 h.

After the photocatalytic reaction is completed, the petroleum coke homogenate is washed with water, filtered and dried.

Rhodococcus sp. DQ-07 (deposited in the "China General Microbial Culture Collection and Management Center", deposit number: CGMCC 1.60022) was inoculated into 50 mL BSM medium and cultured in a shaking incubator at 30°C for 2 days.

The BSM culture medium used in the present invention: 10 g of glucose, 2 g of ammonium chloride, 2.44 g of potassium dihydrogen phosphate, 14.02 g of disodium hydrogen phosphate dodecahydrate, 0.2 g of magnesium chloride hexahydrate, 0.04 g of anhydrous calcium chloride, Copper chloride hydrate 0.01 g, zinc chloride 0.002 g, cobalt chloride hexahydrate 0.004 g, aluminum chloride hexahydrate 0.001 g, boric acid 0.001 g, ferric chloride hexahydrate 0.04 g, sodium molybdate dihydrate 0.001 g, tetrahydrate Hydrated manganese chloride 0.008 g, sterilized at 121°C for 20 minutes.

Add 0.5 g of pretreated petroleum coke to the desulfurization medium and culture it at 30-35°C for 6-10 d. After the culture, the culture solution containing petroleum coke is filtered, washed and dried, and its sulfur content is measured.

Technical advantages of the present invention.

1. Both photocatalytic oxidative desulfurization and biological desulfurization technologies are carried out at normal temperature and pressure, and have the advantages of mild reaction conditions and safe and controllable reaction processes.

2. Nano-titanium dioxide has an antibacterial effect. When the photocatalyst is solidified into a glass film, it can reduce the loss rate of the photocatalyst and will not affect subsequent biological desulfurization.

3. Photocatalytic oxidation simplifies the "4S pathway" of traditional biological desulfurization into two steps. At the same time, it uses its strong oxidizing properties to destroy the external structure of petroleum coke and improve the hydrophilicity of the petroleum coke surface, which can maximize the effectiveness of desulfurization bacteria. Desulfurization characteristics greatly shorten the desulfurization cycle.

Description of the drawings

Figure 1 Scanning electron microscope image of iron-doped titanium dioxide (70K×).

Figure 2 Comparison of contact angles before (a) and after (b) pretreatment of petroleum coke.

Figure 3 Collaborative desulfurization effect diagram.

Detailed ways

The following first prepares a photocatalyst film, and then explains the technical features of the present invention in conjunction with specific implementation cases of biological desulfurization. It should be noted that the specific cases are only used to explain the present invention and do not limit the scope of use of the present invention.

Example 1: A high-sulfur petroleum coke high-efficiency desulfurization process is as follows.

Ethanol, tetrabutyl titanate, iron nitrate aqueous solution and glacial acetic acid were added in sequence at a volume ratio of 50:10:8:15, and the hydrolysis reaction was carried out under magnetic stirring and ultrasonic vibration to obtain titanium dioxide with an iron-doped amount of 4 wt%. Sol, aged at room temperature for 24 hours.

The iron-doped titanium dioxide sol was fixed on the glass slide by coating using the dipping and pulling method, and then heat-treated at 450°C for 2 h.

Take 0.5 g of petroleum coke with a particle size less than 200 mesh and add it to a petri dish containing 14.5 mL of deionized water. Then add 0.5 mL of 30% hydrogen peroxide as an auxiliary oxidant. After stirring evenly, add 2 iron-doped titanium dioxide films.

In the photocatalytic reactor, a 200 W mercury lamp was used for irradiation for 8 h.

The petroleum coke homogenate after photocatalytic oxidation is filtered, washed and dried.

Rhodococcus sp. DQ-07 was inoculated into 50 mL BSM medium and cultured in a shaker at 30°C for 2 days.

Weigh 0.5 g of the petroleum coke sample after photocatalytic pretreatment, add it to the culture medium of Rhodococcus sp .

After the culture, the culture solution containing petroleum coke was filtered, washed and dried, and its sulfur content was measured. The highest desulfurization rate was 51.92%.

Example 2: A high-sulfur petroleum coke high-efficiency desulfurization process is as follows.

Ethanol, tetrabutyl titanate, iron nitrate aqueous solution and glacial acetic acid were added in sequence at a volume ratio of 50:10:8:15, and the hydrolysis reaction was carried out under magnetic stirring and ultrasonic vibration to obtain titanium dioxide with an iron-doped amount of 4 wt%. Sol, aged at room temperature for 24 hours;

The iron-doped titanium dioxide sol was fixed on the glass slide by coating using the dipping and pulling method, and then heat-treated at 450°C for 2 h.

Take 0.5 g of petroleum coke with a particle size less than 200 mesh and add it to a petri dish containing 14.5 mL of deionized water. Then add 0.5 mL of 30% hydrogen peroxide as an auxiliary oxidant. After stirring evenly, add 2 iron-doped titanium dioxide films.

In the photocatalytic reactor, a 200 W mercury lamp was used for irradiation for 8 h.

The petroleum coke homogenate after photocatalytic oxidation is filtered, washed and dried.

Gordonia was inoculated into 50 mL BSM medium and cultured in a shaker at 30°C for 2 days.

Weigh 0.5 g of the petroleum coke sample after photocatalytic pretreatment, wrap it in sterilized nylon cloth, put it into Gordonella's culture medium, and continue to culture it in a shaker at 30°C for 8 d.

After the culture, the culture solution containing petroleum coke was filtered, washed and dried, and its sulfur content was measured. The highest desulfurization rate was 29.42%.

Example 3: A high-sulfur petroleum coke high-efficiency desulfurization process is as follows.

Ethanol, tetrabutyl titanate, aqueous iron nitrate solution and glacial acetic acid were added in sequence at a volume ratio of 10:50:8:15, and the hydrolysis reaction was carried out under magnetic stirring and ultrasonic vibration to obtain titanium dioxide with an iron-doped amount of 4 wt%. Sol, aged at room temperature for 24 hours.

The iron-doped titanium dioxide sol was fixed on the glass slide by coating using the dipping and pulling method, and then heat-treated at 450°C for 2 h.

Take 0.5 g of petroleum coke with a particle size less than 200 mesh and add it to a petri dish containing 14.5 mL of deionized water. Then add 0.5 mL of 30% hydrogen peroxide as an auxiliary oxidant. After stirring evenly, add 2 iron-doped titanium dioxide films.

In the photocatalytic reactor, a 200 W mercury lamp was used for irradiation for 8 h.

The petroleum coke homogenate after photocatalytic oxidation is filtered, washed and dried.

HPJ bacteria were inoculated into 50 mL BSM medium and cultured in a shaker at 30°C for 2 days.

Weigh 0.5 g of the petroleum coke sample after photocatalytic pretreatment, add it to the culture medium of HPJ bacteria, and continue to culture it in a shaker at 30°C for 8 d.

After the culture, the culture solution containing petroleum coke was filtered, washed and dried, and its sulfur content was measured. The highest desulfurization rate was 34.47%.

Claims (7)

1. The efficient desulfurizing process for high sulfur petroleum coke features the photocatalytic pre-treatment of iron doped titania film to petroleum coke and biological desulfurizing, and the process includes the following steps:

under the irradiation of a mercury lamp, carrying out photocatalytic oxidation pretreatment on petroleum coke water homogenate by utilizing a photocatalytic film;

biological desulfurization is carried out on the pretreated petroleum coke by utilizing the desulfurization bacteria, and the pretreated petroleum coke is added into a desulfurization culture medium for biological desulfurization;

washing the petroleum coke sample after biological desulfurization with water, filtering and drying to obtain the desulfurized petroleum coke.

2. The high-efficiency desulfurization process of high-sulfur petroleum coke according to claim 1, wherein the iron-doped titanium dioxide film is prepared by a sol-gel method, and the iron-doped amount is 1-4 wt%.

3. The high-efficiency desulfurization process of high-sulfur petroleum coke according to claim 1, wherein the liquid-solid ratio of the photocatalytic pretreatment petroleum coke is 10-30 mL/g, and the photocatalytic oxidation pretreatment time is 8-12 h.

4. The efficient desulfurization process for high-sulfur petroleum coke according to claim 3, wherein hydrogen peroxide is added as an auxiliary oxidant in the process of photo-catalytic pretreatment of petroleum coke.

5. The high-efficiency desulfurization process of high-sulfur petroleum coke according to claim 1, wherein desulfurization bacteria are inoculated into a desulfurization medium and cultured for 2-3 d.

6. The efficient desulfurization process for high-sulfur petroleum coke according to claim 5, wherein the pretreated petroleum coke sample is added into desulfurization medium and cultured at 30-35 ℃ for 6-16 d.

7. The high-efficiency desulfurization process for high-sulfur petroleum coke according to claim 6, wherein the liquid-solid ratio of petroleum coke to desulfurization medium is 50-100 mL/g.