Combined adsorbent adsorption system

Abstract

The utility model discloses a combined adsorbent adsorption system which comprises an adsorption tank I and an adsorption tank II, a bottom adsorbent, a middle adsorbent and an upper adsorbent are sequentially filled in the adsorption tank I and the adsorption tank II from bottom to top, and the top ends of the adsorption tank I and the adsorption tank II are respectively connected with an up-to-standard discharge pipe through discharge branch pipes. A valve I and a valve II are respectively mounted on the discharge branch pipes corresponding to the adsorption tank I and the adsorption tank II; the bottoms of the adsorption tank I and the adsorption tank II are respectively connected with the desorption system through communicating pipes. The adsorption tank I and the adsorption tank II are arranged to perform adsorption and desorption in turn, so that the working efficiency is improved, physical temperature rise caused by adsorption can be reduced, the safety risk of adsorption operation is reduced, the volume utilization rate of an adsorbent is improved, the service life of activated carbon in the adsorbent is prolonged, and the frequency of generating solid waste is reduced; the effect of ensuring safe operation of the VOCs recovery and adsorption process and ensuring that emission reaches the standard is achieved.

Description

Technical Field

[0001] This utility model relates to the field of VOCs recovery technology, specifically to a combined adsorbent adsorption system. Background Technology

[0002] Currently, the end-of-pipe process for VOCs (volatile organic compounds) recovery in the industry is the "adsorption" process, which is mostly a physical adsorption process. When treating high-boiling-point media with volatile heavy components such as tar, residual oil, and heavy oil, the adsorption process is exothermic, and components with higher melting and boiling points are more easily adsorbed. During adsorption, gas molecules move towards the solid surface, and their molecular motion speed decreases, releasing heat—this is the heat of adsorption. The heat of adsorption reduces the adsorption efficiency and poses a risk of burning the container during VOCs treatment (activated carbon is flammable). Media with high melting and boiling points adhering to the surface of activated carbon also reduce the adsorption effect of the micropores of the adsorbent. Substances with high melting and boiling points are also difficult to completely desorb in conventional vacuum desorption, thus reducing the adsorption volume of activated carbon and consequently reducing its service life.

[0003] To address the adsorption conditions of VOCs containing components with high melting and boiling points, and to ensure safe operation of the adsorption process while ensuring emissions meet standards, a combined adsorbent adsorption system was designed and proposed. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a combined adsorbent adsorption system to ensure the safe operation of the VOCs recovery and adsorption process and to ensure that emissions meet standards.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] A combined adsorbent adsorption system includes an adsorption tank 1 and an adsorption tank 2. The adsorption tank 1 and the adsorption tank 2 are filled with a bottom layer adsorbent, a middle layer adsorbent and an upper layer adsorbent from bottom to top. The tops of the adsorption tank 1 and the adsorption tank 2 are respectively connected to a compliant discharge pipe through discharge branch pipes. Valve 1 and valve 2 are respectively installed on the corresponding discharge branch pipes of the adsorption tank 1 and the adsorption tank 2.

[0007] The bottoms of adsorption tank 1 and adsorption tank 2 are respectively connected to the desorption system through connecting pipes, and valve 5 and valve 6 are respectively installed on the corresponding connecting pipes of adsorption tank 1 and adsorption tank 2. The corresponding connecting pipes of adsorption tank 1 and adsorption tank 2 are connected to each other through exhaust gas branch pipes, and the two ends of the exhaust gas branch pipes are respectively connected to the connecting pipes between adsorption tank 1 and valve 5 and between adsorption tank 2 and valve 6.

[0008] The exhaust gas branch pipe is equipped with valve three and valve four, and an exhaust gas pipeline located between valve three and valve four is connected to the exhaust gas branch pipe.

[0009] Preferably, the bottom layer adsorbent, the middle layer adsorbent, and the top layer adsorbent are hydrophobic silica gel adsorbent, coconut shell activated carbon adsorbent, and coal-based activated carbon adsorbent, respectively.

[0010] Preferably, the upper end of the connecting pipe extends into the interior of adsorption tank one and adsorption tank two and is connected to a horizontally arranged annular pipe. The surface of the annular pipe is uniformly provided with through holes and the end is sealed.

[0011] Preferably, both adsorption tank one and adsorption tank two are provided with a distributor located below the bottom adsorbent, and the distributor is provided with perforations.

[0012] Preferably, the perforation density near the edge of the distributor is less than the perforation density near the center.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] This invention, by setting up adsorption tank one and adsorption tank two to perform adsorption and desorption alternately, not only improves working efficiency but also reduces the physical temperature rise caused by adsorption, lowers the safety risks of adsorption operation, improves the volume utilization rate of the adsorbent, extends the service life of the activated carbon in the adsorbent, and reduces the frequency of solid waste generation. It achieves the effect of ensuring safe operation of the VOCs recovery adsorption process while ensuring that emissions meet standards. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the internal structure of adsorption tank 1 and adsorption tank 2 of this utility model;

[0017] Figure 3 This is a top view of the annular tube of this utility model;

[0018] Figure 4 This is a top view of the distributor of this utility model.

[0019] In the diagram: 1. Bottom layer adsorbent; 2. Middle layer adsorbent; 3. Top layer adsorbent; 4. Adsorption tank one; 5. Adsorption tank two; 6. Desorption system; 7. Valve three; 8. Valve four; 9. Valve one; 10. Valve two; 11. Valve five; 12. Valve six; 13. Discharge branch pipe; 14. Compliant discharge pipe; 15. Connecting pipe; 16. Exhaust gas pipeline; 17. Ring pipe; 18. Through hole; 19. Distributor; 20. Perforation; 21. Exhaust gas branch pipe. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] like Figure 1-4 As shown, this utility model provides a technical solution: a combined adsorbent adsorption system, including an adsorption tank 1 4 and an adsorption tank 2 5. The adsorption tank 1 4 and the adsorption tank 2 5 are filled with a bottom layer adsorbent 1, a middle layer adsorbent 2 and an upper layer adsorbent 3 from bottom to top. The bottom layer adsorbent 1, the middle layer adsorbent 2 and the upper layer adsorbent 3 are respectively a hydrophobic silica gel adsorbent, a coconut shell activated carbon adsorbent and a coal-based activated carbon adsorbent.

[0022] The bottom adsorbent 1 can be replaced by an adsorbent with a low calorific value and a high proportion of mesopores in the pore size distribution. The middle adsorbent 2 can be replaced by zeolite or an adsorbent with a relatively uniform pore size distribution, depending on the adsorption medium. The top adsorbent 3 can be replaced by an adsorbent with a micropore ratio of more than 95%.

[0023] The bottom adsorbent 1 uses hydrophobic silica gel adsorbent, which is less flammable, has low heat of adsorption, high mechanical properties, and stable chemical properties compared to activated carbon. It is suitable for adsorbing components with high melting and boiling points. The pore size of silica gel is mainly 2~10nm. This layer mainly reduces the heat of adsorption and improves the utilization rate of the adsorbent micropores.

[0024] The middle layer adsorbent 2 uses coconut shell activated carbon adsorbent to further adsorb VOCs and also serves as an intermediate buffer layer, while the light components in VOCs enter the upper layer for adsorption.

[0025] The upper adsorbent 3 uses coal-based activated carbon adsorbent, which generally has a larger specific surface area than coconut shell activated carbon and a higher proportion of micropores. It can better adsorb light hydrocarbons in VOCs and better assist in meeting emission standards under strict emission requirements.

[0026] The thickness of different adsorption layers in the adsorption bed is calculated based on the adsorption capacity of different adsorbents and the content of each component of VOCs to be treated. The loading capacity of a single adsorbent can be estimated using the following empirical formula:

[0027] ;

[0028] in:

[0029] Q—Adsorbent loading amount (kg);

[0030] C—The volume of waste gas to be treated (m³ / h);

[0031] —Volume percentage of the components to be processed;

[0032] —The average molecular weight of the component to be treated (g / mol);

[0033] h — Designed adsorbent time per tank;

[0034] —Gas molar volume (L / mol) under adsorption conditions;

[0035] —The adsorption capacity of the adsorbent for this component (g / g);

[0036] The adsorbent loading amount estimated by the above formula is the theoretical minimum loading amount. It needs to be comprehensively designed in combination with the adsorption tank design, desorption effect and desorption of mixed components in the adsorbent.

[0037] The tops of adsorption tank 4 and adsorption tank 5 are respectively connected to the compliant discharge pipe 14 through discharge branch pipe 13, and valve 9 and valve 10 are respectively installed on the discharge branch pipe 13 corresponding to adsorption tank 4 and adsorption tank 5.

[0038] The bottoms of adsorption tank 4 and adsorption tank 5 are connected to desorption system 6 via connecting pipe 15. Desorption system 6 can be a vacuum desorption system, high temperature desorption system, etc.

[0039] The upper end of the connecting pipe 15 extends into the interior of adsorption tank 4 and adsorption tank 5 and is connected to the horizontally arranged annular pipe 17. The surface of the annular pipe 17 is uniformly provided with through holes 18 and the end is sealed. Inside both adsorption tank 4 and adsorption tank 5, there is a distributor 19 located below the bottom adsorbent 1. The distributor 19 is provided with perforations 20. The density of the perforations 20 near the edge of the distributor 19 is less than that near the center, which reduces the amount of liquid droplets in the exhaust gas entering the adsorbent with the airflow, reduces the adsorption volume of the adsorbent, and ensures uniform distribution of exhaust gas. Since the density of the multi-layer adsorbent is different, uneven density may occur during the filling process, which prevents the exhaust gas from passing directly through the low pressure resistance channel without sufficient adsorption.

[0040] Valve 11 and valve 12 are respectively installed on the connecting pipe 15 corresponding to adsorption tank 4 and adsorption tank 5. The connecting pipe 15 corresponding to adsorption tank 4 and adsorption tank 25 are connected by exhaust gas branch pipe 21, and the two ends of exhaust gas branch pipe 21 are respectively connected to the connecting pipe 15 between adsorption tank 4 and valve 11 and between adsorption tank 25 and valve 12.

[0041] The exhaust branch pipe 21 is equipped with valve 3 7 and valve 4 8, and the exhaust branch pipe 21 is connected to the exhaust pipe 16 located between valve 3 7 and valve 4 8.

[0042] Working principle:

[0043] After pretreatment, VOCs waste gas is adsorbed in adsorption tank 4, while desorption occurs in adsorption tank 5. Valves 7, 9, and 12 are opened, while valves 8, 10, and 11 are closed. Similarly, when adsorption tank 5 is used for adsorption, adsorption tank 4 is used for desorption. Valves 8, 10, and 11 are opened, while valves 7, 9, and 12 are closed. VOCs waste gas enters from the bottom of adsorption tanks 4 and 5, is dispersed through the through-holes in the annular pipe 17 and the perforations in the distributor, and is adsorbed sequentially by the bottom, middle, and top adsorbent layers. The alternating adsorption and desorption processes of adsorption tanks 4 and 5 not only improve efficiency but also reduce the physical temperature rise caused by adsorption, thus lowering the safety risks associated with adsorption operation.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A combined adsorbent adsorption system, characterized in that: It includes an adsorption tank 1 (4) and an adsorption tank 2 (5). The adsorption tank 1 (4) and the adsorption tank 2 (5) are filled with bottom adsorbent (1), middle adsorbent (2) and top adsorbent (3) from bottom to top. The top of the adsorption tank 1 (4) and the adsorption tank 2 (5) are respectively connected to the compliant discharge pipe (14) through the discharge branch pipe (13). The corresponding discharge branch pipe (13) of the adsorption tank 1 (4) and the adsorption tank 2 (5) are respectively equipped with valve 1 (9) and valve 2 (10). The bottoms of the adsorption tank 1 (4) and the adsorption tank 2 (5) are connected to the desorption system (6) through connecting pipes (15), and valves 5 (11) and 6 (12) are installed on the connecting pipes (15) corresponding to the adsorption tank 1 (4) and the adsorption tank 2 (5), respectively. The connecting pipes (15) corresponding to the adsorption tank 1 (4) and the adsorption tank 2 (5) are connected to each other through exhaust gas branch pipes (21), and the two ends of the exhaust gas branch pipes (21) are connected to the connecting pipes (15) between the adsorption tank 1 (4) and valves 5 (11) and between the adsorption tank 2 (5) and valves 6 (12), respectively. The exhaust gas branch pipe (21) is equipped with valve three (7) and valve four (8), and the exhaust gas branch pipe (21) is connected to an exhaust gas pipe (16) located between valve three (7) and valve four (8).

2. The combined adsorbent adsorption system according to claim 1, characterized in that: The bottom layer adsorbent (1), the middle layer adsorbent (2), and the top layer adsorbent (3) are respectively hydrophobic silica gel adsorbent, coconut shell activated carbon adsorbent, and coal-based activated carbon adsorbent.

3. The combined adsorbent adsorption system according to claim 1, characterized in that: The upper end of the connecting pipe (15) extends into the interior of the first adsorption tank (4) and the second adsorption tank (5) and is connected to the horizontally arranged annular pipe (17). The surface of the annular pipe (17) is uniformly provided with through holes (18) and the end is sealed.

4. The combined adsorbent adsorption system according to claim 1, characterized in that: Both the first adsorption tank (4) and the second adsorption tank (5) are equipped with a distributor (19) located below the bottom adsorbent (1), and the distributor (19) is provided with perforations (20).

5. The combined adsorbent adsorption system according to claim 4, characterized in that: The density of perforations (20) near the edge of the distributor (19) is less than the density of perforations (20) near the center.

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