Device for removing heavy components in food-grade carbon dioxide production
By combining a two-step liquefaction process with a molecular sieve deweighting unit, the problems of high energy consumption and unstable product quality in the removal of heavy components in food-grade carbon dioxide production have been solved, thus achieving the production of high-purity carbon dioxide.
Patent Information
- Application Number
- CN202520131601.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-01-20
AI Technical Summary
In existing technologies, heavy component removal equipment in the production of food-grade carbon dioxide consumes a lot of energy, requires a large amount of adsorbent, and requires frequent regeneration, resulting in unstable product quality.
A two-step liquefaction process is adopted, using two condensers and a gas-liquid separator, combined with a molecular sieve deweighting unit, to reduce the amount of adsorbent and the number of regeneration times. The carbon dioxide temperature is lowered to below the dew point through the second condenser, further separating the heavy components.
Without increasing operating costs, the purity and quality of carbon dioxide products were improved, energy consumption and adsorbent usage were reduced, and deep removal of heavy components was ensured.
Smart Images
Figure CN223774322U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to gas purification technical field, concretely relates to a kind of removal device of heavy component in food-grade carbon dioxide production. BACKGROUND
[0002] Carbon dioxide is a gaseous compound at room temperature, and it is the most important greenhouse gas. It is the gas referred to in carbon emissions. However, carbon dioxide also has important practical applications. It is widely used in the chemical industry, food industry, mechanical processing, oil exploration and many other fields. Depending on the source and use, the production and processing techniques of carbon dioxide and the quality requirements for the product vary greatly. Carbon dioxide used for food has very high quality requirements, and most of the raw materials come from industrial waste gas.
[0003] The main process flow of the heavy component removal equipment in current carbon dioxide production is: gas compression, desulfurization, dehydrocarbon, heavy component removal, pressurized liquefaction, light component removal, and finally liquid carbon dioxide product is obtained. In this step, the heavy component removal, molecular sieve and other types of adsorbent (catalyst) are often used, and the adsorbent dosage is large, the regeneration is frequent, the energy consumption is high, the heavy component separation efficiency is relatively low, and some heavy component removal is complex, which requires multiple catalysts and multiple removal equipment for removal, often leading to unstable product quality.
[0004] Based on the above problems, the utility model provides a kind of removal device of heavy component in food-grade carbon dioxide production. UTILITY MODEL CONTENT
[0005] The utility model aims to provide a kind of removal device of heavy component in food-grade carbon dioxide production, in order to realize the above-mentioned purpose, the technical scheme that the utility model adopts is:
[0006] A kind of removal device of heavy component in food-grade carbon dioxide production, comprising:
[0007] Raw material gas inlet;
[0008] Molecular sieve heavy component removal unit, connected with raw material gas inlet;
[0009] First condenser, connected with molecular sieve heavy component removal unit;
[0010] First gas-liquid separator, connected with first condenser, and light component discharge port is provided on the first gas-liquid separator;
[0011] Distillation column, connected with first gas-liquid separator.
[0012] Further, the second condenser and the second gas-liquid separator are arranged between the molecular sieve heavy component removal unit and the first condenser, one end of the second condenser is connected with the molecular sieve heavy component removal unit, the other end of the second condenser is connected with the second gas-liquid separator, the second gas-liquid separator is connected with the first condenser, and a heavy component discharge port is arranged on the second gas-liquid separator.
[0013] Further, the outlet temperature of the second condenser is 2-10 DEG C lower than the dew point of the inlet raw gas.
[0014] Further, the buffer tank is arranged between the molecular sieve heavy component removal unit and the second condenser.
[0015] Further, the buffer tank is arranged between the molecular sieve heavy component removal unit and the second condenser.
[0016] Further, the water separator is arranged between the compressor and the molecular sieve heavy component removal unit.
[0017] Further, the water separator is arranged between the compressor and the molecular sieve heavy component removal unit.
[0018] Further, the water separator is arranged between the compressor and the molecular sieve heavy component removal unit.
[0019] Further, the water separator is arranged between the compressor and the molecular sieve heavy component removal unit.
[0020] The device has the following advantages:
[0021] The device has the following advantages: BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 The device has the following advantages:
[0023] The device has the following advantages: DETAILED DESCRIPTION
[0024] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so as to better understand the purpose, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are only for illustrating the essential spirit of the technical solution of the present invention.
[0025] The main process flow for heavy component removal equipment in traditional carbon dioxide production is as follows: gas compression, desulfurization, dehydrocarbonization, heavy component removal, pressurized liquefaction, and light component removal. The final product is liquid carbon dioxide. The heavy component removal step often uses adsorbents (catalysts) such as molecular sieves. This step involves large adsorbent usage, frequent regeneration, high energy consumption, and relatively low separation efficiency for heavy components. Some heavy component removal is complex, requiring multiple catalysts and removal equipment, often leading to unstable product quality.
[0026] This invention proposes a device for removing heavy components in the production of food-grade carbon dioxide. It divides the liquefaction process into two steps, reducing the amount of adsorbent used, the number of regeneration cycles, and energy consumption in the molecular sieve deweighting section without increasing operating costs, while ensuring deep removal of heavy components. Specifically... Figure 1 As shown, the system includes a raw material gas inlet 1, a molecular sieve deweighting unit 2, a first condenser 3, a first gas-liquid separator 4, and a distillation column 5. The molecular sieve deweighting unit 2 is connected to the raw material gas inlet 1; the first condenser 3 is connected to the molecular sieve deweighting unit 2; the first gas-liquid separator 4 is connected to the first condenser 3, and the first gas-liquid separator 4 is equipped with a light component discharge outlet; the distillation column 5 is connected to the first gas-liquid separator 4. The raw material contains light components, carbon dioxide, and a small amount of heavy components. The first gas-liquid separator separates the light components at the top and a small amount of heavy components and carbon dioxide at the bottom. Using only one condenser and one gas-liquid separator will result in a small amount of heavy components not being separated, and the carbon dioxide purity will be low.
[0027] To achieve higher purity of the separated carbon dioxide, one embodiment further includes a second condenser 6 and a second gas-liquid separator 7. The second condenser 6 and the second gas-liquid separator 7 are positioned between the molecular sieve deweighting unit 2 and the first condenser 3. One end of the second condenser 6 is connected to the molecular sieve deweighting unit 2, and the other end is connected to the second gas-liquid separator 7. The second gas-liquid separator 7 is connected to the first condenser 3, and a heavy component discharge port is provided on the second gas-liquid separator 7. In this embodiment, the top of the second gas-liquid separator 7 separates light components and carbon dioxide, while the bottom separates a small amount of heavy components. Thus, the first gas-liquid separator outputs light components at the top and carbon dioxide at the bottom, resulting in higher purity.
[0028] In one embodiment, the outlet temperature of the second condenser 6 is 2°C to 10°C lower than the dew point of the inlet raw material gas (i.e., carbon dioxide mixture).
[0029] In the above embodiment, the liquefaction process is divided into two steps, implemented using two condensers. The second condenser lowers the temperature of the carbon dioxide mixture after the removal of heavy components to approximately 2°C–10°C below the dew point of the carbon dioxide mixture. A large amount of carbon dioxide, still gaseous, enters the first condenser and is completely liquefied, while the heavy components (water, methanol, tar, etc.) liquefy and separate from the second condenser, further removing the heavy components. This achieves a dual effect of cooling and heavy component removal, resulting in higher purity carbon dioxide. In contrast, traditional methods fail to separate the heavy components, which then enter the product, reducing product quality.
[0030] In this embodiment, an additional condenser is added, but the composition, mass, and temperature of the substance to be condensed remain unchanged, and the required heat load remains the same. Therefore, the sum of the heat loads of the two condensers does not increase compared to the traditional method. Moreover, the two condensers have high heat transfer efficiency and require a small heat exchange area, thus their weight is also small. Therefore, the total area and weight of the condensers are smaller than those of a single condenser in the traditional method.
[0031] In one embodiment, a buffer tank 8 is also included, one end of which is connected to the raw material gas inlet 1 and the other end is connected to the molecular sieve deweighting unit 2.
[0032] In one embodiment, a compressor 9 is provided between the buffer tank 8 and the molecular sieve deweighting unit 2.
[0033] In one embodiment, a water separator 10 is provided between the compressor 9 and the molecular sieve deweighting unit 2.
[0034] In one embodiment, an adsorption dryer 11 is provided between the water separator 10 and the molecular sieve deweighting unit 2.
[0035] In one embodiment, an ethylene adsorber 12 is provided between the adsorption dryer 11 and the molecular sieve deweighting unit 2.
[0036] In one embodiment, an activated carbon adsorber 13 is provided between the ethylene adsorber 12 and the molecular sieve deweighting unit 2.
[0037] like Figure 1As shown, the raw material gas (i.e., carbon dioxide gas) enters the buffer tank of the device through the external pipeline network, is compressed by the compressor unit, cooled by the post-water cooler, and then enters the water separator to separate water. After entering the adsorption dryer, it further removes trace amounts of moisture. The carbon dioxide gas after removal passes through the ethylene adsorber to make the ethylene content in the raw material gas ≤5ppm. Then it enters the activated carbon adsorber to remove odors, and then passes through the molecular sieve deweighting unit for deweighting. Then it enters the second condenser to lower the temperature of the carbon dioxide mixture after the heavy components are removed to about 2℃-10℃ below the dew point of the carbon dioxide mixture. A large amount of carbon dioxide is still gaseous and enters the first condenser to be completely liquefied, while the heavy components (water, methanol, tar, etc.) are liquefied and separated from the second condenser for further removal of heavy components. The light components are output from the top of the first gas-liquid separator, and carbon dioxide is output from the bottom. The separated carbon dioxide enters the distillation tower for further separation to obtain food-grade liquid carbon dioxide product. Food-grade liquid carbon dioxide products can be subcooled by a product subcooler and then stored in a liquid carbon dioxide storage tank. The liquid carbon dioxide can be transported to the user's mobile tanker by a carbon dioxide transfer pump, or it can be vaporized by a carbon dioxide bottling pump and then transported to the bottling room.
Claims
1. A device for removing heavy components in the production of food-grade carbon dioxide, characterized in that, include: Raw gas inlet (1); The molecular sieve deweighting unit (2) is connected to the raw material gas inlet (1); The first condenser (3) is connected to the molecular sieve deweighting unit (2); The first gas-liquid separator (4) is connected to the first condenser (3), and the first gas-liquid separator (4) is provided with a light component discharge port; The distillation column (5) is connected to the first gas-liquid separator (4).
2. The device for removing heavy components in the production of food-grade carbon dioxide according to claim 1, characterized in that, It also includes a second condenser (6) and a second gas-liquid separator (7). The second condenser (6) and the second gas-liquid separator (7) are disposed between the molecular sieve deweighting unit (2) and the first condenser (3). One end of the second condenser (6) is connected to the molecular sieve deweighting unit (2), and the other end of the second condenser (6) is connected to the second gas-liquid separator (7). The second gas-liquid separator (7) is connected to the first condenser (3). The second gas-liquid separator (7) is provided with a heavy component discharge outlet.
3. The device for removing heavy components in the production of food-grade carbon dioxide according to claim 2, characterized in that, The outlet temperature of the second condenser (6) is 2°C to 10°C lower than the dew point of the inlet raw material gas.
4. A device for removing heavy components in the production of food-grade carbon dioxide according to claim 1 or 2, characterized in that, It also includes a buffer tank (8), one end of which is connected to the raw material gas inlet (1), and the other end is connected to the molecular sieve deweighting unit (2).
5. The apparatus for removing heavy components in the production of food-grade carbon dioxide according to claim 4, characterized in that, A compressor (9) is provided between the buffer tank (8) and the molecular sieve deweighting unit (2).
6. The apparatus for removing heavy components in the production of food-grade carbon dioxide according to claim 5, characterized in that, A water separator (10) is provided between the compressor (9) and the molecular sieve deweighting unit (2).
7. The apparatus for removing heavy components in the production of food-grade carbon dioxide according to claim 6, characterized in that, An adsorption dryer (11) is provided between the water separator (10) and the molecular sieve deweighting unit (2).
8. The apparatus for removing heavy components in the production of food-grade carbon dioxide according to claim 7, characterized in that, An ethylene adsorber (12) is provided between the adsorption dryer (11) and the molecular sieve deweighting unit (2).
9. The apparatus for removing heavy components in the production of food-grade carbon dioxide according to claim 8, characterized in that, An activated carbon adsorber (13) is provided between the ethylene adsorber (12) and the molecular sieve deweighting unit (2).