A device for producing food-grade carbon dioxide by using sweet potato fermentation tail gas

Abstract

This utility model relates to the field of gas purification technology, and in particular discloses a device for producing food-grade carbon dioxide using potato fermentation tail gas. The device includes a pretreatment module, a compression module, a purification module, a distillation module, a refrigeration module, and a storage module. These modules are connected sequentially via pipelines. The inlet and outlet ports of the refrigeration module are connected to the refrigeration ports of the distillation module. This utility model provides a cold source through the refrigeration module and employs a low-temperature distillation process, reducing power consumption to 150±5% kW / h, a reduction of more than 32% compared to traditional processes. It also improves product purity to 99.995% and enables the production of liquid carbon dioxide and dry ice, achieving the goal of switching between industrial-grade (99.8%) and high-purity (99.9994%) products.

Description

Technical Field

[0001] This utility model relates to the field of gas purification technology, and in particular to a device for producing food-grade carbon dioxide using the tail gas from potato fermentation. Background Technology

[0002] During the fermentation of potatoes to produce alcohol, a large amount of fermentation tail gas containing carbon dioxide is generated, with a carbon dioxide content of approximately 94% (v / v), as well as impurities such as nitrogen, oxygen, hydrogen, methane, alcohols, and sulfides. Traditional equipment for producing carbon dioxide from this tail gas mostly employs adsorption-catalysis, which has the following drawbacks: complex process operation, requiring regular replacement of adsorbents and catalysts, resulting in high operating costs; high power consumption; and poor stability, making it difficult to meet the needs of the high-end food industry.

[0003] Therefore, it is necessary to propose an improvement to overcome the shortcomings of the existing technology. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the prior art and provide a device for producing food-grade carbon dioxide using potato fermentation tail gas, thereby solving the problems of complex processes, high costs, and poor stability in traditional purification equipment.

[0005] The technical solution of this utility model is: An apparatus for producing food-grade carbon dioxide using potato fermentation tail gas includes a pretreatment module, a compression module, a purification module, a distillation module, a refrigeration module, and a storage module. The pretreatment module, compression module, purification module, distillation module, and storage module are connected in sequence via pipelines. The inlet and outlet ports of the refrigeration module are respectively connected to the refrigeration ports of the distillation module.

[0006] As a preferred technical solution, the pretreatment module includes a raw material gas holder, a first filter, a second filter, a precooler, and a gas-liquid separator. The discharge end of the raw material gas holder is connected to the inlet ends of the first filter and the second filter, respectively. The discharge ends of the first filter and the second filter are both connected to the inlet end of the precooler. The discharge end of the precooler is connected to the inlet end of the gas-liquid separator, and the discharge end of the gas-liquid separator is connected to the inlet end of the compression module.

[0007] As a preferred technical solution, the compression module is configured as a piston compressor, the feed end of the piston compressor is connected to the discharge end of the pretreatment module, and the discharge end of the piston compressor is connected to the feed end of the purification module.

[0008] As a preferred technical solution, the purification module includes a first desulfurization tower, a second desulfurization tower, a post-precooler, a first molecular sieve, and a second molecular sieve. The discharge end of the compression module is connected to the feed ends of the first and second desulfurization towers, respectively. The discharge ends of the first and second desulfurization towers are both connected to the feed end of the post-precooler. The discharge end of the post-precooler is connected to the feed ends of the first and second molecular sieves, respectively. The discharge ends of the first and second molecular sieves are both connected to the feed end of the distillation module.

[0009] As a preferred technical solution, both the first molecular sieve and the second molecular sieve are equipped with an electric heater and a Roots blower.

[0010] As a preferred technical solution, the distillation module includes a subcooler, a first distillation column, a liquefier, and a second distillation column. The discharge end of the purification module is connected to the feed end of the first distillation column, the discharge end of the first distillation column is connected to the feed end of the liquefier, the discharge end of the liquefier is connected to the feed end of the second distillation column, the discharge end of the second distillation column is connected to the feed end of the subcooler, and the liquid outlet end of the subcooler is connected to the storage module.

[0011] As a preferred technical solution, the first distillation column is connected to a second gas-liquid separator, and the second gas-liquid separator is connected to a residual liquid recovery tank.

[0012] As a preferred technical solution, the second distillation column is equipped with a non-condensable gas discharge port.

[0013] As a preferred technical solution, the refrigeration module includes an ice room and a liquid nitrogen storage tank. The outlet end of the ice room is connected to the inlet end of the liquid nitrogen storage tank. The refrigeration outlet end of the distillation module is connected to the inlet end of the ice room, and the outlet end of the liquid nitrogen storage tank is connected to the refrigeration inlet end of the distillation module.

[0014] As a preferred technical solution, the storage module includes a carbon dioxide storage tank, which is connected to a gas cylinder filling station, a filling line and a dry ice machine, and the filling line is connected to a tank truck filling station.

[0015] Compared with the prior art, the beneficial effects of this utility model are: This invention relates to a device for producing food-grade carbon dioxide using potato fermentation tail gas. The device includes a pretreatment module, a compression module, a purification module, a distillation module, a refrigeration module, and a storage module. The refrigeration module provides a cold source, employing a low-temperature distillation process, reducing power consumption to 150±5% kW / h, a reduction of over 32% compared to traditional processes. It also improves product purity to 99.995%, enabling the production of both liquid carbon dioxide and dry ice, thus achieving the goal of switching between industrial-grade (99.8%) and high-purity (99.9994%) products. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the connection structure of the device for producing food-grade carbon dioxide using potato fermentation tail gas according to this utility model.

[0017] The system comprises: 1. Pretreatment module; 11. Raw material gas holder; 12. First filter; 13. Second filter; 14. Pre-cooler; 15. First gas-liquid separator; 2. Compression module; 3. Purification module; 31. Electric heater; 32. First molecular sieve; 33. Second molecular sieve; 34. First desulfurization tower; 35. Second desulfurization tower; 36. Post-cooler; 37. Roots blower; 4. Distillation module; 41. Subcooler; 42. Second distillation tower; 43. Liquefaction unit; 44. First distillation tower; 45. Refrigeration ice machine; 5. Refrigeration module; 6. Storage module; 61. Carbon dioxide storage tank; 62. Gas cylinder filling station; 63. Filling outlet; 64. Dry ice machine; 65. Tank truck filling station; 7. Non-condensable gas emission port; 8. Second gas-liquid separator; 9. Residual liquid recovery tank. Detailed Implementation

[0018] To make the technical means, technical features, utility model purpose and technical effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations.

[0019] like Figure 1 The diagram shown is a schematic diagram of the connection structure of the device for producing food-grade carbon dioxide using potato fermentation tail gas according to this utility model.

[0020] The device for producing food-grade carbon dioxide using potato fermentation tail gas in this embodiment includes a pretreatment module 1, a compression module 2, a purification module 3, a distillation module 4, a refrigeration module 5, and a storage module 6. The pretreatment module 1, compression module 2, purification module 3, distillation module 4, and storage module 6 are connected in sequence via pipelines. The refrigeration module 5 provides cooling capacity to the entire device and is connected to the inlet and outlet ends of the cold source of the entire device.

[0021] The pretreatment module includes a raw material gas holder 11, a first filter 12, a second filter 13, a precooler 14, and a first gas-liquid separator 15. The outlet of the raw material gas holder 11 is connected to the inlet of the first filter 12 and the inlet of the second filter 13. The outlets of the first filter 12 and the second filter 13 are both connected to the inlet of the precooler 14. The outlet of the precooler 14 is connected to the inlet of the first gas-liquid separator 15. The outlet of the first gas-liquid separator 15 is connected to the compression module 2. The pretreatment module 1 is used to remove grease, some aldehydes and alcohols, and moisture from the raw material gas. Both the first filter 12 and the second filter 13 are filled with activated carbon. After the raw material gas is filtered by activated carbon adsorption, it enters the precooler 14 to be cooled to 10°C, and then passes through the first gas-liquid separator 15 to separate liquid water, thereby improving the efficiency of the subsequent compressor.

[0022] Compression module 2 adopts a three-stage piston compressor. The feed end of the piston compressor is connected to the discharge end of the first gas-liquid separator 15, and the discharge end of the piston compressor is connected to the purification module 3. The piston compressor compresses the raw material gas in three stages to 2.5-3.0 MPa. The matching buffer reduces pressure fluctuations and provides the required pressure for subsequent purification and distillation.

[0023] The purification module 3 includes a first desulfurization tower 34, a second desulfurization tower 35, a first molecular sieve 32, a second molecular sieve 33, and a post-precooler 36. The discharge end of the piston compressor is connected to the inlet ends of the first desulfurization tower 34 and the second desulfurization tower 35, respectively. The discharge ends of both the first and second desulfurization towers 34 and 35 are connected to the inlet end of the post-precooler 36, and the discharge end of the post-precooler 36 is connected to the inlet ends of the first molecular sieve 32 and the second molecular sieve 33, respectively. The discharge ends of both the first and second molecular sieves 32 and 33 are connected to the inlet end of the distillation module 4. The compressed gas first passes through the desulfurization towers to remove sulfides, then passes through the post-precooler 36 to cool to 5°C, and finally passes through the molecular sieve towers for deep dehydration to avoid freezing and blockage during subsequent low-temperature processes.

[0024] Both the first molecular sieve 32 and the second molecular sieve 33 are equipped with electric heaters 31, and the electrolyzer 31 is equipped with a Roots blower 37 for heating the molecular sieves, thereby accelerating the dehydration efficiency of the gas in the molecular sieves.

[0025] The distillation module 4 adopts a skid-mounted cold box structure. The distillation module 4 includes a subcooler 41, a first distillation column 44, a liquefier 43, and the first distillation column 44. The outlets of the first molecular sieve 32 and the second molecular sieve 33 are both connected to the inlet of the first distillation column 44. The outlet of the first distillation column 44 is connected to the inlet of the liquefier 43, and the outlet of the liquefier 43 is connected to the inlet of the second distillation column 42. The outlet of the second distillation column 42 is connected to the inlet of the subcooler 41, and the liquid outlet of the subcooler 41 is connected to the storage module 6. The first distillation column 44 is connected to a second gas-liquid separator 8, and a residual liquid recovery tank 9 is connected to the second gas-liquid separator 8. The bottom of the second distillation column 42 is equipped with a liquid outlet, which can output liquid carbon dioxide with a purity ≥99.995%. The second distillation column 42 is equipped with a non-condensable gas discharge port 7 for discharging non-condensable gases from the second distillation column. The first distillation column 44 removes high-boiling-point impurities (water and alcohols), and the bottom liquid (containing 10% alcohol) is recovered to the wastewater workshop; the second distillation column 42 further purifies the product to produce food-grade liquid carbon dioxide with a purity of ≥99.995%, which is then subcooled to -24℃ after three-stage condensation.

[0026] Refrigeration module 5 consists of an ice room and a liquid nitrogen storage tank. The outlet of the ice room is connected to the inlet of the liquid nitrogen storage tank. The refrigeration outlet of distillation module 4 is connected to the inlet of the ice room, and the outlet of the liquid nitrogen storage tank is connected to the refrigeration inlet of distillation module 4. Both the pre-cooler 14 and the post-cooler 36 are connected to the piping of refrigeration module 5 to provide cooling for the pre-coolers and distillation column. Liquid ammonia is recycled and replenished periodically.

[0027] The storage module 6 includes a carbon dioxide storage tank 61, which is connected to a gas cylinder filling station 62, a filling line 63 and a dry ice machine 64 via pipelines. The filling line 63 is connected to a tank truck filling station 65. Liquid carbon dioxide can be directly filled for external sale, or dry ice (125×105×(10-60)mm) or granular (Φ3mm) dry ice can be produced by the dry ice machine unit.

[0028] This device also includes an automatic controller, which contains a PLC automatic control system. All electrical components of this device are connected to the automatic controller for the automatic control and operation of the overall equipment.

[0029] Working principle: Raw material gas treatment: The tail gas from potato fermentation (CO2 94%, temperature 30℃, pressure 0.12MPa) is buffered by the raw material gas tank 11, and then enters the first filter 12 and the second filter 13 to adsorb oil and aldehyde alcohol impurities. It is then cooled to 10℃ by the precooler 14, and the first gas-liquid separator 15 separates the water before entering the compressor. Compression: The gas is compressed to 2.5-3.0 MPa by a piston compressor, and the pressure is stabilized by a buffer during the process; Purification: The compressed gas first passes through the first desulfurization tower 34 and the second desulfurization tower 35 to remove hydrogen sulfide, and then passes through the post-precooler 36 to cool down to 5°C. The first molecular sieve 32 and the second molecular sieve 33 perform deep dehydration (water content ≤20μL / L). Distillation: After purification, the gas enters the distillation module 4, the first distillation column 44 removes heavy components, and the second distillation column 42 distills to obtain liquid CO2 with a purity ≥99.995%, which is then subcooled to -24℃ and enters the storage module 6. Product output: Liquid CO2 is stored in carbon dioxide storage tank 61, and part of it is made into dry ice by dry ice unit. The storage time is ≤24h, and it is transported as soon as it is produced.

[0030] In this utility model, the device for producing food-grade carbon dioxide from potato fermentation tail gas is based on existing technology for all its components. The patented technology is a gas purification device composed of the connection structure of the components.

[0031] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. All equivalent changes and modifications made in accordance with the scope of the claims of this utility model should fall within the technical scope of this utility model.

Claims

1. A device for producing food-grade carbon dioxide using potato fermentation tail gas, characterized in that, It includes a pretreatment module (1), a compression module (2), a purification module (3), a distillation module (4), a refrigeration module (5), and a storage module (6). The pretreatment module (1), compression module (2), purification module (3), distillation module (4), and storage module (6) are connected in sequence through pipes. The inlet and outlet ports of the refrigeration module (5) are connected to the refrigeration ports of the distillation module (4).

2. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 1, characterized in that, The pretreatment module (1) includes a raw material gas tank (11), a first filter (12), a second filter (13), a precooler (14), and a gas-liquid separator (15). The discharge end of the raw material gas tank (11) is connected to the inlet end of the first filter (12) and the second filter (13), respectively. The discharge ends of the first filter (12) and the second filter (13) are both connected to the inlet end of the precooler (14). The discharge end of the precooler (14) is connected to the inlet end of the gas-liquid separator (15). The discharge end of the gas-liquid separator (15) is connected to the inlet end of the compression module (2).

3. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 1, characterized in that, The compression module (2) is configured as a piston compressor. The feed end of the piston compressor is connected to the discharge end of the pretreatment module (1), and the discharge end of the piston compressor is connected to the feed end of the purification module (3).

4. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 1, characterized in that, The purification module (3) includes a first desulfurization tower (34), a second desulfurization tower (35), a post-precooler (36), a first molecular sieve (32), and a second molecular sieve (33). The discharge end of the compression module (2) is connected to the feed ends of the first desulfurization tower (34) and the second desulfurization tower (35), respectively. The discharge ends of the first desulfurization tower (34) and the second desulfurization tower (35) are both connected to the feed end of the post-precooler (36). The discharge end of the post-precooler (36) is connected to the feed ends of the first molecular sieve (32) and the second molecular sieve (33), respectively. The discharge ends of the first molecular sieve (32) and the second molecular sieve (33) are both connected to the feed end of the distillation module (4).

5. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 4, characterized in that, Both the first molecular sieve (32) and the second molecular sieve (33) are equipped with an electric heater (31) and a Roots blower (37).

6. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 1, characterized in that, The distillation module (4) includes a subcooler (41), a first distillation column (44), a liquefier (43), and a second distillation column (42). The discharge end of the purification module (3) is connected to the feed end of the first distillation column (44). The discharge end of the first distillation column (44) is connected to the feed end of the liquefier (43). The discharge end of the liquefier (43) is connected to the feed end of the second distillation column (42). The discharge end of the second distillation column (42) is connected to the feed end of the subcooler (41). The liquid outlet end of the subcooler (41) is connected to the storage module (6).

7. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 6, characterized in that, The first distillation column (44) is connected to a second gas-liquid separator (8), and the second gas-liquid separator (8) is connected to a residual liquid recovery tank (9).

8. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 6, characterized in that, The second distillation column (42) is equipped with a non-condensable gas discharge port (7).

9. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 1, characterized in that, The refrigeration module (5) includes an ice machine room and a liquid nitrogen storage tank. The outlet end of the ice machine room is connected to the inlet end of the liquid nitrogen storage tank. The refrigeration outlet end of the distillation module (4) is connected to the inlet end of the ice machine room, and the outlet end of the liquid nitrogen storage tank is connected to the refrigeration inlet end of the distillation module (4).

10. The apparatus for producing food-grade carbon dioxide from potato fermentation tail gas according to claim 1, characterized in that, The storage module (6) includes a carbon dioxide storage tank (61), which is connected to a gas cylinder filling station (62), a filling line (63) and a dry ice machine (64), respectively. The filling line (63) is connected to a tank truck filling station (65).

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