Combined transportation system and method of tail gas oxidation absorption process and wastewater double-alkali softening process

Abstract

The invention relates to the technical field of petrochemical engineering processes, and particularly discloses a combined transportation system and method of a tail gas oxidation absorption process and a wastewater double-alkali softening process, and the combined transportation system comprises a wastewater treatment device and a tail gas treatment device connected with the wastewater treatment device; the tail gas treatment device comprises a tail gas treatment tower for generating acidic wastewater and a liquid discharge pipeline connected with the tail gas treatment tower; and a control valve and a filter are sequentially arranged on the liquid discharge pipeline along the flowing direction of the acid wastewater. The acid wastewater is used as the neutralization acid liquor for wastewater treatment, so that wastewater recycling is realized, and compared with the prior art, the consumption of acid and alkali liquor is reduced; the acid wastewater is filtered by the filter through the pressure in the liquid discharge pipeline and then conveyed to the intermediate tank, so that compared with the prior art, the investment of super stainless steel equipment such as a tail gas neutralization storage tank and a tail gas and wastewater pump skid and matched pipelines is reduced, and the cost is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of petrochemical process technology, and more specifically, to a combined system and method for tail gas oxidation absorption and wastewater dual-alkali softening processes. Background Technology

[0002] Natural gas, as a low-carbon and environmentally friendly clean energy source, is being vigorously developed in my country, and natural gas purification technology is widely used. However, due to factors such as process flow and parameter control, the tail gas treatment unit generates a large amount of highly acidic wastewater during operation. This highly acidic wastewater is neutralized and then enters the wastewater treatment unit for further treatment. The wastewater treatment unit uses processes such as dual alkali treatment, flocculation, ultrafiltration, resin treatment, and reverse osmosis to treat and reuse the wastewater, achieving zero wastewater discharge. Currently, the tail gas and wastewater processes are designed as independent sections, without integrated design. This results in long process flows, high investment in equipment and facilities, high initial construction costs and daily operation and maintenance costs, and the generation of a large amount of hazardous waste, becoming a long-standing problem plaguing the industry.

[0003] The existing process discharges highly acidic wastewater from the tail gas into a neutralization storage tank. After adding alkali to neutralize and adjust the pH to 7-8, it is pumped to a wastewater equalization tank before entering the wastewater treatment unit for further treatment. The wastewater treatment unit employs processes such as dual alkali treatment, flocculation, ultrafiltration, resin treatment, and reverse osmosis for wastewater treatment and reuse. Figure 2 Among them, the neutralization tank, wastewater lift pump skid, and supporting pipelines of the exhaust gas treatment device are made of corrosion-resistant super stainless steel, resulting in high construction investment and operation and maintenance costs. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a combined system and method for tail gas oxidation absorption and wastewater dual-alkali softening processes; using acidic wastewater as a neutralizing acid for wastewater treatment realizes wastewater resource utilization and reduces the consumption of acid and alkali solutions compared to existing technologies; relying on the pressure in the discharge pipeline to filter the acidic wastewater through a filter and then transport it to the intermediate tank, which reduces the investment in super stainless steel equipment such as tail gas neutralization storage tanks, tail gas and wastewater pump skids and supporting pipelines compared to existing technologies, and greatly reduces costs;

[0005] The solution adopted by this invention to solve the technical problem is:

[0006] A combined system for tail gas oxidation absorption and wastewater dual alkali softening processes includes a wastewater treatment device and a tail gas treatment device connected to the wastewater treatment device.

[0007] The exhaust gas treatment device includes an exhaust gas treatment tower that generates acidic wastewater, and a discharge pipeline connected to the exhaust gas treatment tower.

[0008] A control valve and a filter are sequentially installed on the drain line along the flow direction of the acidic wastewater.

[0009] In some possible implementations, a level regulating valve is also provided on the drain line, and the level regulating valve is located between the control valve and the output port of the tail gas treatment tower.

[0010] In some possible implementations, the wastewater treatment device includes a reaction tank with an alkali injection port, an intermediate tank connected to the reaction tank, and a filter tank connected to the intermediate tank; the intermediate tank is connected to the output end of a drain line.

[0011] In some possible implementations, the reaction tank includes a dual-alkali reaction tank, a PAC reaction tank, a PAM reaction tank, and an inclined tube settling tank connected in sequence; the inclined tube settling tank is connected to an intermediate tank; the alkali inlet is located on the dual-alkali reaction tank, and the alkali inlet and outlet are in two sets, including a sodium carbonate inlet and a sodium hydroxide inlet.

[0012] In some possible implementations, the filter tank includes a multi-media filter tank connected to an intermediate tank and an ultrafiltration tank connected to the multi-media filter tank.

[0013] In some possible implementations, the exhaust gas treatment tower is a Venturi tower; the drain line is made of UPVC material; and the filter is a Y-type filter.

[0014] A method for co-operating a system combining a tail gas oxidation absorption process and a wastewater dual-alkali softening process as described above specifically includes the following steps:

[0015] After being treated by the wastewater treatment device, the wastewater is converted into alkaline wastewater and stored in an intermediate tank.

[0016] The exhaust gas treatment tower transports acidic wastewater to the intermediate tank through the discharge pipeline;

[0017] In the intermediate tank, alkaline wastewater and highly acidic wastewater are neutralized to obtain a mixed solution after the reaction.

[0018] The filter tank will filter the mixture.

[0019] In some possible implementations, the tail gas treatment tower transports acidic wastewater to an intermediate tank via a discharge pipeline, specifically:

[0020] The acidic wastewater in the Venturi tower is regulated by level regulating valves and control valves to maintain a stable liquid level in the Venturi tower. The discharged acidic wastewater is filtered through a Y-type filter and then transported to the intermediate tank.

[0021] In some possible implementations, the wastewater is treated by a wastewater treatment device to generate alkaline wastewater, which is then stored in an intermediate tank. Specifically, this means:

[0022] After the wastewater enters the dual-alkali reaction tank, alkali solution is added to the tank to reduce the hardness of the wastewater; then it enters the PAC reaction tank and PAM reaction tank for treatment in sequence.

[0023] The treated wastewater enters the inclined tube settling tank, and then enters the intermediate tank.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] This invention uses acidic wastewater as a neutralizing acid solution, realizing the resource utilization of wastewater; it reduces the investment in super stainless steel equipment and supporting pipelines such as tail gas neutralization storage tanks, tail gas wastewater pump skids, etc., thereby reducing the initial construction investment and daily operating costs.

[0026] This invention eliminates the need for acidic wastewater to enter the dual-alkali reaction tank, instead using it as the acid solution for the wastewater, thus realizing wastewater resource utilization and reducing the consumption of acid and alkali solutions.

[0027] This invention relies on the pressure inside the drainage pipeline to filter acidic wastewater through a Y-type filter and then transport it to the intermediate tank, which reduces the investment in the construction of super stainless steel equipment and supporting pipelines such as tail gas neutralization storage tanks, tail gas and wastewater pump skids. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the connection relationship in this invention;

[0029] Figure 2 This is a schematic diagram illustrating the connection relationships in existing technologies;

[0030] The components include: 1. Liquid level regulating valve; 2. Control valve; 3. Filter; 4. Drainage pipeline; 100. Wastewater treatment device; 10. Double alkali reaction tank; 20. PAC reaction tank; 30. PAM reaction tank; 40. Inclined tube sedimentation tank; 50. Intermediate tank; 60. Filter tank; 200. Tail gas treatment device. Detailed Implementation

[0031] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] The present invention will now be described in detail.

[0033] like Figure 1 As shown, a combined system of tail gas oxidation absorption process and wastewater dual alkali softening process includes a wastewater treatment device 100 and a tail gas treatment device 200 connected to the wastewater treatment device 100.

[0034] The exhaust gas treatment device 200 includes an exhaust gas treatment tower that generates acidic wastewater and a drain pipeline 4 connected to the exhaust gas treatment tower for discharging the acidic wastewater.

[0035] A control valve 2 and a filter 3 are sequentially installed on the drain line 4 along the flow direction of the acidic wastewater;

[0036] The exhaust gas treatment tower is a Venturi tower; the drain line 4 is made of UPVC material; and the filter 3 is a Y-type filter 3.

[0037] Filter 3 filters the highly acidic wastewater from the tail gas treatment tower and then transports it to the tail gas treatment device 200, where it is neutralized with the wastewater treated in the wastewater treatment device 100. The neutralized mixture is then filtered by the wastewater treatment device 100 and discharged.

[0038] The drainage pipeline 4 is made of UPVC material, which is low in cost, corrosion resistant, safe and reliable in operation, and convenient for later maintenance.

[0039] In some possible implementations, a liquid level regulating valve 1 is also provided on the drain line 4, and the liquid level regulating valve 1 is located between the control valve 2 and the output port of the tail gas treatment tower.

[0040] The level regulating valve 1 is an automatic regulating valve that maintains a stable level in the Venturi tower by regulating the discharge of highly acidic wastewater.

[0041] In some possible implementations, in order to effectively treat wastewater, the wastewater is converted into alkaline wastewater; the wastewater treatment device 100 includes a reaction tank with an alkaline injection port, an intermediate tank 50 connected to the reaction tank, and a filter tank 60 connected to the intermediate tank 50; the intermediate tank 50 is connected to the output end of the drain line 4.

[0042] The reaction tank is set up to convert wastewater into alkaline wastewater and neutralize it;

[0043] Intermediate tank 50 is used for the neutralization of alkaline and acidic wastewater;

[0044] The filter tank 60 is used to filter the mixture formed after the neutralization reaction in the intermediate tank 50.

[0045] In some possible implementations, in order to effectively treat wastewater, the reaction tank includes a dual alkali reaction tank 10, a PAC reaction tank 20, a PAM reaction tank 30, and an inclined tube sedimentation tank 40 connected in sequence; the inclined tube sedimentation tank 40 is connected to an intermediate tank 50; and the alkali injection port is located on the dual alkali reaction tank 10.

[0046] After the wastewater enters the dual alkali reaction tank 10, alkali solution is added through the alkali solution injection port to convert it into alkaline wastewater. After passing through the PAC reaction tank 20 and the PAM reaction tank 30, it enters the inclined tube settling tank 40 and then enters the intermediate tank 50 through the inclined tube settling tank 40.

[0047] In some possible implementations, the filter tank 60 includes a multi-media filter tank connected to the intermediate tank 50 and an ultrafiltration tank connected to the multi-media filter tank.

[0048] Because highly acidic wastewater has low hardness and high salinity, there is no need for flocculation and sedimentation to reduce hardness or remove suspended solids. Using highly acidic wastewater as a neutralizing acid reduces acid consumption. The elimination of neutralization treatment for highly acidic wastewater reduces alkali consumption. Highly acidic wastewater does not enter the reaction tanks (dual alkali reaction tank 10, PAC reaction tank 20, PAM reaction tank 30, inclined tube sedimentation tank 40) of the wastewater treatment device 100, thus reducing the ion concentration in the wastewater, extending the service life and effectiveness of the reaction tanks, and improving the production efficiency and safety of the equipment. The reduced ion concentration in the concentrated water produced by the wastewater treatment device 100 decreases the amount of hazardous waste generated by the evaporation and crystallization device, achieving efficient, safe, and environmentally friendly production.

[0049] A method for co-operating a system combining a tail gas oxidation absorption process and a wastewater dual-alkali softening process as described above specifically includes the following steps:

[0050] After being treated by the wastewater treatment device 100, the wastewater is converted into alkaline wastewater and stored in the intermediate tank 50.

[0051] After the wastewater enters the dual-alkali reaction tank 10 in the wastewater treatment device 100, alkali solution is added to the dual-alkali reaction tank 10 to reduce the hardness of the wastewater. The alkali solution here is sodium carbonate and sodium hydroxide. Then it enters the PAC reaction tank 20 and PAM reaction tank 30 in sequence for treatment. The treated wastewater enters the inclined tube settling tank 40 and then enters the intermediate tank 50.

[0052] The exhaust gas treatment tower transports the acidic wastewater to the intermediate tank 50 through the drain pipeline 4;

[0053] The acidic wastewater in the Venturi tower is regulated by level regulating valve 1 and control valve 2 to maintain a stable liquid level in the Venturi tower. The discharged acidic wastewater is filtered by Y-type filter 3 and then transported to intermediate tank 50.

[0054] In the intermediate tank 50, alkaline wastewater and highly acidic wastewater are neutralized to obtain a mixed liquid after reaction.

[0055] The filter tank 60 will filter the mixture.

[0056] This invention directly directs acidic wastewater to the wastewater treatment device 100 for use as a neutralizing acid solution, thus realizing the resource utilization of wastewater. By using the intermediate water storage tank of the wastewater treatment device as an intermediate pool 50, the investment in super stainless steel equipment and supporting pipelines such as tail gas neutralization storage tanks, tail gas wastewater pump skids, etc. is reduced, thereby reducing the initial construction investment and daily operation and maintenance costs.

[0057] The invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A combined system for tail gas oxidation absorption and wastewater dual-alkali softening processes, characterized in that, This includes wastewater treatment equipment and exhaust gas treatment equipment connected to the wastewater treatment equipment; The exhaust gas treatment device includes an exhaust gas treatment tower that generates acidic wastewater, and a discharge pipeline connected to the exhaust gas treatment tower. A control valve and a filter are sequentially installed on the drain line along the flow direction of the acidic wastewater.

2. The combined operation system of tail gas oxidation absorption process and wastewater dual-alkali softening process according to claim 1, characterized in that, A liquid level regulating valve is also installed on the drain pipeline, and the liquid level regulating valve is located between the control valve and the output port of the tail gas treatment tower.

3. The combined operation system of tail gas oxidation absorption process and wastewater dual-alkali softening process according to claim 1, characterized in that, The wastewater treatment device includes a reaction tank with an alkali injection port, an intermediate tank connected to the reaction tank, and a filter tank connected to the intermediate tank; the intermediate tank is connected to the output end of the drainage pipeline.

4. The combined operation system of tail gas oxidation absorption process and wastewater dual alkali softening process according to claim 3, characterized in that, The reaction tank includes a dual-alkali reaction tank, a PAC reaction tank, a PAM reaction tank, and an inclined tube settling tank connected in sequence; the inclined tube settling tank is connected to an intermediate tank; the alkali injection port is located on the dual-alkali reaction tank, and the alkali inlet and outlet are in two sets, including a sodium carbonate injection port and a sodium hydroxide injection port.

5. The combined operation system of tail gas oxidation absorption process and wastewater dual-alkali softening process according to claim 3, characterized in that, The filter tank includes a multi-media filter tank connected to the intermediate tank and an ultrafiltration tank connected to the multi-media filter tank.

6. A combined system for tail gas oxidation absorption and wastewater dual-alkali softening processes according to any one of claims 1-5, characterized in that, The exhaust gas treatment tower is a Venturi tower; the drain pipeline is made of UPVC material; and the filter is a Y-type filter.

7. A method for co-transporting a tail gas oxidation absorption process and a wastewater dual-alkali softening process according to any one of claims 1-6, characterized in that, Specifically, the following steps are included: After being treated by the wastewater treatment device, the wastewater is converted into alkaline wastewater and stored in an intermediate tank. The exhaust gas treatment tower transports acidic wastewater to the intermediate tank through the discharge pipeline; In the intermediate tank, alkaline wastewater and highly acidic wastewater are neutralized to obtain a mixed solution after the reaction. The filter tank will filter the mixture.

8. The method for co-operating a tail gas oxidation absorption process and a wastewater dual-alkali softening process according to claim 7, characterized in that, The aforementioned tail gas treatment tower transports acidic wastewater to the intermediate tank via a discharge pipeline, specifically referring to: The acidic wastewater in the Venturi tower is regulated by level regulating valves and control valves to maintain a stable liquid level in the Venturi tower. The discharged acidic wastewater is filtered through a Y-type filter and then transported to the intermediate tank.

9. The method for co-operating a tail gas oxidation absorption process and a wastewater dual-alkali softening process according to claim 7, characterized in that, The wastewater, after being treated by the wastewater treatment device, is converted into alkaline wastewater and stored in an intermediate tank. Specifically, this means: After the wastewater enters the dual-alkali reaction tank, alkali solution is added to the tank to reduce the hardness of the wastewater; then it enters the PAC reaction tank and PAM reaction tank for treatment in sequence. The treated wastewater enters the inclined tube settling tank, and then enters the intermediate tank.

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