Absorption of high sulfur compounds in biodiesel distillates

Abstract

This utility model discloses an absorption device for high-sulfur compounds in biodiesel distillates: adsorption packing is provided on both sides of the baffle in the front and rear adsorption towers; the high-sulfur, low-component distillate pipeline of the distillation tower is divided into two paths, one connected to the top left side of the front adsorption tower and the other to the top right side of the rear adsorption tower after connecting to the feed valve and the cleaning liquid inlet valve; the top outlet pipelines of the front and rear adsorption towers are divided into two paths: a discharge pipeline with a desulfurized compound discharge valve and a cleaning liquid discharge pipeline with a cleaning liquid discharge valve. The discharge pipelines of the two adsorption towers merge into a desulfurized compound output main pipeline, and the cleaning liquid discharge pipelines of the two adsorption towers merge into a cleaning liquid discharge main pipeline; the bottom of the cones of both the front and rear adsorption towers are connected to a material discharge pipeline with a material venting valve, and the two merge into a material venting main pipeline. This utility model solves the problems of low biodiesel yield and difficulty in recovering by-products by distillation, which affect product quality and production costs in the prior art.

Description

Technical Field

[0001] This utility model relates to the technical field of biodiesel production equipment, specifically to an absorption device for high-sulfur compounds in biodiesel distillates. Background Technology

[0002] Biodiesel, as an environmentally friendly renewable energy source, is mainly produced from animal and vegetable oils or waste oils through esterification and transesterification reactions, and plays an important role in reducing carbon emissions and alleviating the energy crisis. However, biodiesel produced from waste animal and vegetable oils often contains oxygen- and nitrogen-containing organic sulfur compounds such as glucosinolates and isothiocyanates due to the decomposition of food residues in the raw materials, with sulfur content typically ranging from tens to over one hundred mg / kg.

[0003] Existing desulfurization technologies face numerous challenges. While traditional hydrodesulfurization technology is mature in the petrochemical diesel sector, its direct application to biodiesel is not only costly but also leads to the saturation of carbon-carbon double bonds in unsaturated fatty acid esters, disrupting their chemical structure. Furthermore, existing biodiesel desulfurization processes, such as distillation desulfurization and bio-oxidation-reduction desulfurization, while achieving some desulfurization effect, still have limitations. For example, distillation requires precise temperature and pressure control, resulting in high energy consumption; while bio-oxidation-reduction desulfurization has limited adaptability to feedstocks, and its processing efficiency is significantly affected by microbial activity. Based on existing biodiesel distillation processes, although sulfur-containing biodiesel compounds can meet standards as the main product, a small amount of byproducts are enriched with sulfur compounds at elevated concentrations, significantly reducing their economic value. This results in low yields of biodiesel as the main product, meeting quality standards, and difficulties in recovering byproducts through redistillation, impacting product quality and production costs. Summary of the Invention

[0004] The purpose of this invention is to provide an absorption device for high-sulfur compounds in biodiesel distillate that is highly selective, operates under mild conditions, consumes little energy, does not damage the quality of biodiesel, has a simple and compact structure, and is easy and efficient to operate. This device significantly reduces the content of low-component high-sulfur compounds in biodiesel distillate, and solves the problems of low biodiesel yield and difficulty in recovering by-products through redistillation that affect product quality and production costs in the existing technology.

[0005] To achieve the above objectives, the absorption device for high-sulfur compounds in biodiesel distillate of this invention includes a pre-adsorption tower 11 and a post-adsorption tower 12, with a partition plate inside each tower. The pre-adsorption tower 11 has a left pre-adsorption packing 13 and a right pre-adsorption packing 15 on either side of the partition plate, and the post-adsorption tower 12 has a left post-adsorption packing 16 and a right post-adsorption packing 14 on either side of the partition plate. The high-sulfur, low-component distillate pipeline of the distillation tower is divided into two paths: one path connects to the top left side of the pre-adsorption tower 11 after connecting the pre-adsorption tower feed valve 1 and the cleaning liquid pipeline with the pre-adsorption tower cleaning liquid inlet valve 3; the other path connects to the right side of the post-adsorption tower 12 after connecting the post-adsorption tower feed valve 2 and the cleaning liquid pipeline with the post-adsorption tower cleaning liquid inlet valve 4. At the top; the right top outlet pipe of the front adsorption tower 11 splits into two paths: a discharge pipe with a discharge valve 5 for the desulfurized compound from the front tower and a cleaning liquid discharge pipe with a discharge valve 7 for the front tower cleaning liquid. The left top outlet pipe of the rear adsorption tower 12 splits into two paths: a discharge pipe with a discharge valve 6 for the desulfurized compound from the rear tower and a cleaning liquid discharge pipe with a discharge valve 8 for the rear tower cleaning liquid. The discharge pipes of the two adsorption towers merge into a main outlet pipe for the desulfurized compound, and the cleaning liquid discharge pipes of the two adsorption towers merge into a main outlet pipe for the cleaning liquid. The conical bottom of the front adsorption tower 11 is connected to a material discharge pipe with a material discharge valve 9 for the front tower, and the rear adsorption tower 12 is connected to a material discharge pipe with a material discharge valve 10 for the rear tower. The two merge into a main material discharge pipe.

[0006] The absorption device for high-sulfur compounds in biodiesel distillate of this invention has the following technical features and

[0007] Beneficial effects:

[0008] 1. The dual-tower, one-tower-operated-and-the-other-tower-as-standby co-adsorption method ensures continuous and stable desulfurization; the packing material is regenerated through alkaline cleaning solution, eliminating the need to stop the machine to replace the packing material, greatly reducing operating and maintenance costs and extending the service life of the equipment; the intermediate partition optimizes the material flow channel, which can significantly improve the adsorption efficiency.

[0009] 2. The operation is simple, convenient and efficient, greatly avoiding operational errors.

[0010] 3. It has a simple and compact structure, low manufacturing and maintenance costs, and reliable operation. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the absorption device for high-sulfur compounds in biodiesel distillate according to this utility model.

[0012] Figure reference numerals: 1. Front tower feed valve; 2. Rear tower feed valve; 3. Front tower cleaning liquid inlet valve; 4. Rear tower cleaning liquid inlet valve; 5. Front tower desulfurized compound discharge valve; 6. Front tower cleaning liquid discharge valve; 7. Rear tower cleaning liquid discharge valve; 8. Front tower material vent valve; 9. Rear tower material vent valve; 10. Front adsorption tower; 11. Rear adsorption tower; 12. Front tower left adsorption packing; 13. Front tower right adsorption packing; 15. Rear tower left adsorption packing; 16. Rear tower right adsorption packing; 14. Detailed Implementation

[0013] The specific implementation of the absorption device for high-sulfur compounds in biodiesel distillate of this utility model will be further described in detail below with reference to the accompanying drawings.

[0014] Figure 1 As shown, the absorption device for high-sulfur compounds in biodiesel distillate of this utility model includes a front adsorption tower 11 and a rear adsorption tower 12, with a middle partition plate inside the tower; the front adsorption tower 11 has a front tower left adsorption packing 13 and a front tower right adsorption packing 15 on both sides of the partition plate, and the rear adsorption tower 12 has a rear tower left adsorption packing 16 and a rear tower right adsorption packing 14 on both sides of the partition plate; the high-sulfur, low-component distillate pipeline of the distillation tower is divided into two paths, one path is connected to the top left side of the front adsorption tower 11 after connecting the front tower feed valve 1 and the cleaning liquid pipeline with the front tower cleaning liquid inlet valve 3, and the other path is connected to the top right side of the rear adsorption tower 12 after connecting the rear tower feed valve 2 and the cleaning liquid pipeline with the rear tower cleaning liquid inlet valve 4. The top outlet pipe on the right side of the front adsorption tower 11 splits into two branches: a discharge pipe with a discharge valve 5 for the desulfurized compound from the front tower and a cleaning liquid discharge pipe with a discharge valve 7 for the front tower cleaning liquid. The top outlet pipe on the left side of the rear adsorption tower 12 splits into two branches: a discharge pipe with a discharge valve 6 for the desulfurized compound from the rear tower and a cleaning liquid discharge pipe with a discharge valve 8 for the rear tower cleaning liquid. The discharge pipes of the two adsorption towers merge into a main discharge pipe for the desulfurized compound, and the cleaning liquid discharge pipes of the two adsorption towers merge into a main discharge pipe for the cleaning liquid. The conical bottom of the front adsorption tower 11 is connected to a material discharge pipe with a material discharge valve 9 for the front tower, and the rear adsorption tower 12 is connected to a material discharge pipe with a material discharge valve 10 for the rear tower. The two merge into a main material discharge pipe.

[0015] During operation, the high-sulfur, low-component distillate from the distillation tower enters the pre-adsorption tower 11 through the pre-tower feed valve 1. After passing through the left adsorption packing 13, it flows through the right adsorption packing 15. The desulfurized compound discharge valve 5 of the pre-tower is opened to discharge the desulfurized compound. During this period, the pre-tower cleaning liquid inlet valve 3, the pre-tower cleaning liquid outlet valve 7, and the pre-tower material vent valve 9 are closed. At the same time, the pre-tower material vent valve 9 is opened at fixed time intervals during operation to discharge glycerol and impurities accumulated at the bottom of the pre-adsorption tower 11 cone. Similarly, the high-sulfur, low-component distillate from the distillation tower enters the post-adsorption tower 12 through the post-tower feed valve 2. It first passes through the right adsorption packing 14 and then flows through the left adsorption packing 16. The desulfurized compound discharge valve 6 of the post-tower is opened to discharge the desulfurized compound. During this period, the post-tower cleaning liquid inlet valve 4, the post-tower cleaning liquid outlet valve 8, and the post-tower material vent valve 10 are closed. At the same time, the post-tower material vent valve 10 is opened at fixed time intervals during operation to discharge glycerol and impurities accumulated at the bottom of the post-adsorption tower 12 cone. The pre-adsorption tower 11 and post-adsorption tower 12, equipped with a middle partition, are normally in a standby state. When the sulfur adsorption effect of the pre-adsorption tower 11 deteriorates, the post-adsorption tower feed valve 2 is opened, allowing the high-sulfur, low-component effluent from the distillation tower to enter the post-pre-adsorption tower 12. Simultaneously, the post-adsorption tower desulfurized compound discharge valve 6 is opened to obtain the desulfurized compound, and the pre-adsorption tower feed valve 1 and the post-adsorption tower desulfurized compound discharge valve 5 of the pre-adsorption tower 11 are closed to complete the tower switching operation, and vice versa. When the pre-adsorption tower 11 is shut down, the material in the pre-adsorption tower 11 is discharged through the pre-adsorption tower material vent valve 9 and then closed. The pre-adsorption tower cleaning liquid inlet valve 3 is opened to allow the alkaline cleaning liquid to flow into the pre-adsorption tower 11. After passing through the left adsorption packing 13, the liquid flows through the right adsorption packing 15. The discharge is controlled by the pre-adsorption tower cleaning liquid discharge valve 7 to clean the sulfur off the adsorption packing. After cleaning is completed, the pre-adsorption tower cleaning liquid inlet valve 3 is closed and the pre-adsorption tower material vent valve 9 is opened to drain the contents of the pre-adsorption tower 11. After draining the alkaline cleaning solution, close the front tower material vent valve 9, then open the front tower feed valve 1 and the front tower desulfurized compound discharge valve 5 to introduce the high-sulfur, low-component material from the tower into the front adsorption tower 11. When there is discharge from the front tower desulfurized compound discharge valve 5, simultaneously close the front tower feed valve 1 and the front tower desulfurized compound discharge valve 5. After standing for 1 hour, open the front tower material vent valve 9 to drain the material from the front adsorption tower 11, completing the replacement of the front adsorption tower 11, and put the tower into standby mode. Similarly, when the rear adsorption tower 12 is used and the sulfur adsorption effect deteriorates, switch to the front adsorption tower 11. The cleaning and replacement of the rear adsorption tower 12 is similar to that of the front adsorption tower 11.

[0016] The absorption device for high-sulfur compounds in biodiesel distillates with the above-described structure has the following characteristics and effects:

[0017] 1. High-efficiency desulfurization: Utilizing a dual-tower system and its internal structure, the high-sulfur and low-carbon components in the tower discharge are effectively desulfurized, thereby accurately separating sulfides, improving material purity, and meeting the raw material quality requirements of subsequent production.

[0018] 2. Flexible cleaning: The alkaline cleaning solution can be controlled by valves to periodically clean the packing structure inside the tower, maintain the cleanliness of the equipment, ensure mass transfer and reaction efficiency, and extend the service life of the equipment.

[0019] 3. Continuous operation guarantee: The dual towers, valves, and outlets work together so that the other tower is running while one tower is cleaning. This allows for switching between material handling and equipment maintenance, ensuring continuous production, reducing downtime losses, and improving overall production efficiency.

Claims

1. An absorption device for high-sulfur compounds in biodiesel distillate, characterized in that: It includes a front adsorption tower (11) and a rear adsorption tower (12), with a middle partition inside the tower; the front adsorption tower (11) has a front tower left adsorption packing (13) and a front tower right adsorption packing (15) on both sides of the partition, and the rear adsorption tower (12) has a rear tower left adsorption packing (16) and a rear tower right adsorption packing (14) on both sides of the partition; the high sulfur low component distillate pipeline of the distillation tower is divided into two paths, one path is connected to the top left side of the front adsorption tower (11) after the front tower feed valve (1) and the cleaning liquid pipeline with the front tower cleaning liquid inlet valve (3), and the other path is connected to the top right side of the rear adsorption tower (12) after the rear tower feed valve (2) and the cleaning liquid pipeline with the rear tower cleaning liquid inlet valve (4); the front adsorption tower (11) The top outlet pipe on the right is divided into two paths: a discharge pipe with a discharge valve (5) for the desulfurized compound from the front tower and a discharge pipe with a discharge valve (7) for the cleaning liquid from the front tower. The top outlet pipe on the left side of the rear adsorption tower (12) is divided into two paths: a discharge pipe with a discharge valve (6) for the desulfurized compound from the rear tower and a discharge pipe with a discharge valve (8) for the cleaning liquid from the rear tower. The discharge pipes of the two adsorption towers merge into a main outlet pipe for the desulfurized compound, and the discharge pipes of the two adsorption towers merge into a main outlet pipe for the cleaning liquid. The cone bottom of the front adsorption tower (11) is connected to a material discharge pipe with a material discharge valve (9) for the front tower, and the rear adsorption tower (12) is connected to a material discharge pipe with a material discharge valve (10) for the rear tower. The two merge into a main outlet pipe for the material.

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