Refining system for C3 to C6 hydrocarbons

Abstract

The invention provides a C3 to C6 hydrocarbon refining system which comprises an input port and an oil-water separator which are connected in sequence, an outlet of the oil-water separator is connected with a first valve bank, the first valve bank is connected with a backflow channel, a first adsorption tower and a second adsorption tower, the outlet end of the backflow channel is connected between the first valve bank and the oil-water separator, and the outlet end of the first adsorption tower is connected with the oil-water separator. A recovery module for cooling the fluid is arranged on the backflow channel; an outlet of the first adsorption tower is connected with a second valve group, the second valve group is connected with an outlet of the second adsorption tower, the second valve group is connected with a filter, a product outlet of the filter is respectively connected with a heating channel and an output port, an outlet end of the heating channel is connected with the second valve group, and a regeneration module for heating fluid is arranged on the heating channel; a reverse flow channel is connected between the first valve group and the second valve group, and an on-off valve is arranged on the reverse flow channel. Compared with the prior art, the invention has the advantages of low energy consumption, less pollutant emission and zero medium consumption.

Description

Technical Field

[0001] This invention relates to the technical field of petrochemicals, and in particular to a refining system for C3 to C6 hydrocarbons. Background Technology

[0002] Traditional refining systems commonly use nitrogen for regeneration. However, nitrogen, as an inert carrier gas, has a high heat capacity, requiring excessive sensible heat input during regeneration, resulting in high energy consumption. Furthermore, the emitted exhaust gas contains volatile organic compounds (VOCs), and even after treatment, current systems still emit trace amounts, ensuring persistent carrier gas pollution. Therefore, there is an urgent need to address these issues. Summary of the Invention

[0003] To address the aforementioned problems, the present invention achieves the above objectives through the following technical solution: a refining system for C3 to C6 hydrocarbons, comprising an input port and an oil-water separator connected in sequence, wherein the outlet of the oil-water separator is connected to a first valve group, the first valve group is respectively connected to a reflux channel, a first adsorption tower and a second adsorption tower, the outlet end of the reflux channel is connected between the first valve group and the oil-water separator, and the reflux channel is provided with a recovery module for cooling the fluid; The outlet of the first adsorption tower is connected to a second valve group, the second valve group is connected to the outlet of the second adsorption tower, the second valve group is connected to a filter, the product outlet of the filter is connected to a heating channel and an output port respectively, the outlet end of the heating channel is connected to the second valve group, and the heating channel is provided with a regeneration module for heating fluid. A counterflow channel is connected between the first valve group and the second valve group, and an on / off valve is provided on the counterflow channel.

[0004] Furthermore, the first valve group includes control valves A, B, C, D, E, F, and G. The inlet of control valve A is connected to the outlet of the oil-water separator, and the outlet of control valve A is connected to the inlet of the first adsorption tower. The inlet of the first adsorption tower is connected in series with control valves B and C, and the inlet of the second adsorption tower is connected in series with control valves D and E. The inlet of control valve F is connected to the outlets of control valves C and E, respectively, and the outlet of control valve F is connected to the inlet of the reflux channel. The inlet of control valve G is connected between the outlet of the oil-water separator and the inlet of control valve A, and the outlet of control valve G is connected between the inlet of control valve D and the outlet of control valve E.

[0005] Furthermore, the second valve group includes control valves H, I, J, K, L, M, and N. The outlet of the first adsorption tower is connected in series with control valves H and I, and the outlet of the second adsorption tower is connected in series with control valves J and K. The outlet of control valve L is connected to the inlet of control valve I and the inlet of control valve K, respectively, and the inlet of control valve L is connected to the outlet of the heating channel. The inlet of control valve M is connected to the inlet of the second adsorption tower, and the outlet of control valve M is connected to the inlet of the filter. The inlet of control valve N is connected between control valves H and I, and the outlet of control valve N is connected between the inlet of the filter and the outlet of control valve M.

[0006] Furthermore, the recycling module includes a cooler, a gas-liquid separator, and a delivery pump. The inlet of the cooler is connected to the outlet of the F control valve, the outlet of the cooler is connected to the inlet of the gas-liquid separator, the gas phase outlet of the gas-liquid separator is connected to a safety flare, the liquid phase outlet of the gas-liquid separator is connected to the inlet of the delivery pump, and the outlet of the delivery pump is connected between the outlet of the oil-water separator and the inlet of the A control valve.

[0007] Furthermore, the regeneration module includes a vaporizer, a flow control valve, and a heater connected in series. The inlet of the vaporizer is connected to the product outlet of the filter, and the outlet of the heater is connected to the inlet of the L control valve.

[0008] Furthermore, the heater controls the fluid temperature at its outlet to be between 150°C and 250°C.

[0009] Furthermore, the flow control valve adjusts the flow rate through the heating channel to account for 2%-15% of the total outlet flow rate of the filter.

[0010] Furthermore, the inlet of the filter is connected between the H control valve and the I control valve, and the exhaust outlet of the filter is connected to the safety flare.

[0011] Furthermore, the inlet end of the counterflow channel is connected to the outlet of the L control valve, and the outlet end of the counterflow channel is connected to the inlet of the F control valve.

[0012] Furthermore, both the first adsorption tower and the second adsorption tower are equipped with a number of temperature sensors, which are spaced apart along the flow direction of the fluid.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: First, by setting a regeneration module on the heating channel, hydrocarbon products can be diverted, then vaporized and heated, thereby serving as a high-temperature regeneration medium. Under the on / off control of the first valve group and the second valve group, it can be reversed and fed into the first adsorption tower or the second adsorption tower, thereby achieving regeneration and utilization. This can significantly reduce the external heat load of the regeneration process, achieve system cascade energy self-sufficiency, and reduce energy consumption. Secondly, by setting up a recycling module in the return channel, the regenerated medium can be condensed and separated. Then, under the on / off control of the first valve group, it can flow through the system again for recycling and reuse, realizing a closed-loop cycle. This ensures that the regenerated medium is not consumed in the system. Only a very small amount of hydrocarbon products need to be diverted to maintain the regeneration needs. The raw material utilization rate can be close to 100%, maximizing resource utilization and reducing pollutant emissions. Thirdly, by setting up this system, there is no need to introduce additional nitrogen or other regeneration media, which can completely replace the problem of continuously replenishing high-purity nitrogen in traditional processes, eliminate nitrogen resource consumption, and the regeneration tail gas does not contain inert nitrogen media, making the tail gas composition simple, the volumetric flow rate extremely small, easy to treat and recover, avoiding the VOCs problem of hydrocarbon nitrogen emissions, with significant environmental advantages, thus solving the technical problems in the prior art; Overall, the present invention has the advantages of low energy consumption, low pollutant emissions and zero media consumption, effectively avoiding energy waste, maximizing resource utilization, and effectively reducing pollutant emissions. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the system connection of the present invention; Figure 2 This is an enlarged schematic diagram of the first valve assembly of the present invention; Figure 3 This is an enlarged schematic diagram of the second valve assembly of the present invention.

[0015] The reference numerals in the attached diagram are explained as follows: 1-Input port; 2-Oil-water separator; 3-First valve group; 301-A control valve; 302-B control valve; 303-C control valve; 304-D control valve; 305-E control valve; 306-F control valve; 307-G control valve; 4-Return channel; 5-First adsorption tower; 6-Second adsorption tower; 7-Second valve group; 701-H control valve; 702-I control valve; 703-J control valve; 704-K control valve; 705-L control valve; 706-M control valve; 707-N control valve; 8-Filter; 9-Heating channel; 10-Output port; 11-Reverse flow channel; 12-On / off valve; 13-Cooler; 14-Gas-liquid separator; 15-Transfer pump; 16-Safety flare; 17-Vaporizer; 18-Flow control valve; 19-Heater; 20-Temperature sensor. Detailed Implementation

[0016] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected to" another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "left," "right," "inner," "outer," and similar expressions used in this specification are for illustrative purposes only.

[0017] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0018] like Figures 1 to 3 As shown, the present invention provides a refining system for C3 to C6 hydrocarbons, including an input port 1 and an oil-water separator 2 connected in sequence. The outlet of the oil-water separator 2 is connected to a first valve group 3. The first valve group 3 is connected to a reflux channel 4, a first adsorption tower 5 and a second adsorption tower 6 respectively. The outlet end of the reflux channel 4 is connected between the first valve group 3 and the oil-water separator 2. The reflux channel 4 is provided with a recovery module for cooling the fluid. The outlet of the first adsorption tower 5 is connected to the second valve group 7, which is connected to the outlet of the second adsorption tower 6. The second valve group 7 is connected to the filter 8. The product outlet of the filter 8 is connected to the heating channel 9 and the output port 10 respectively. The outlet end of the heating channel 9 is connected to the second valve group 7. The heating channel 9 is equipped with a regeneration module for heating the fluid. A counterflow channel 11 is connected between the first valve group 3 and the second valve group 7, and an on / off valve 12 is provided on the counterflow channel 11.

[0019] Preferably, the oil-water filter 1 adopts a multi-stage series configuration. The first stage removes most of the free water and larger mechanical impurities, while the second stage has a filtration accuracy of no less than 0.5μm, ensuring that the raw material entering the adsorption tower meets the requirements. An online moisture analyzer and a particulate matter monitoring sensor are installed between the oil-water filter 1 and the first valve group 3 to monitor the pretreatment effect in real time and communicate with the intelligent control module to provide early warnings of filter replacement needs (e.g., a replacement reminder will be given when the moisture content exceeds 10ppm).

[0020] Preferably, the adsorbents in the first adsorption tower 5 and the second adsorption tower 6 are 3A molecular sieves or modified silica gel, and the regeneration zone of the adsorption tower adopts a radial flow design to improve desorption efficiency and reduce regeneration gas consumption. Both the first adsorption tower 5 and the second adsorption tower 6 are equipped with several temperature sensors 20, which are spaced apart along the fluid flow direction. Temperature sensors 20 are installed at least at the outlet and inlet of the adsorption tower to monitor the adsorption front and regeneration temperature rise in real time, and then feed back to the intelligent control module to intelligently open or close the corresponding valves in the first valve group 3 and the second valve group 7. The intelligent control module preferably adopts a PLC, which is electrically connected to each valve and each sensor, thereby intelligently controlling the on / off state of each valve to intelligently switch the circuit.

[0021] The first valve group 3 includes control valve A 301, control valve B 302, control valve C 303, control valve D 304, control valve E 305, control valve F 306, and control valve G 307. The inlet of control valve A 301 is connected to the outlet of oil-water separator 2, and the outlet of control valve A 301 is connected to the inlet of the first adsorption tower 5. The inlet of the first adsorption tower 5 is connected in series with control valve B 302 and control valve C 303, and the inlet of the second adsorption tower 6 is connected in series with control valve D 304 and control valve E 305. The inlet of control valve F 306 is connected to the outlet of control valve C 303 and the outlet of control valve E 305, and the outlet of control valve F 306 is connected to the inlet of the reflux channel 4. The inlet of control valve G 307 is connected between the outlet of oil-water separator 2 and the inlet of control valve A 301, and the outlet of control valve G 307 is connected between the inlet of control valve D 304 and the outlet of control valve E 305.

[0022] The second valve group 7 includes control valves H 701, I 702, J 703, K 704, L 705, M 706, and N 707. The outlet of the first adsorption tower 5 is connected in series with control valves H 701 and I 702, and the outlet of the second adsorption tower 6 is connected in series with control valves J 703 and K 704. The outlet of control valve L 705 is connected to the inlet of control valve I 702 and the inlet of control valve K 704, respectively, and the inlet of control valve L 705 is connected to the outlet of heating channel 9. The inlet of control valve M 706 is connected to the inlet of the second adsorption tower 6, and the outlet of control valve M 706 is connected to the inlet of filter 8. The inlet of control valve N 707 is connected between control valves H 701 and I 702, and the outlet of control valve N 707 is connected between the inlet of filter 8 and the outlet of control valve M 706.

[0023] The recovery module includes a cooler 13, a gas-liquid separator 14, and a transfer pump 15. The inlet of the cooler 13 is connected to the outlet of control valve F 306, and the outlet of the cooler 13 is connected to the inlet of the gas-liquid separator 14. The gas phase outlet of the gas-liquid separator 14 is connected to a safety flare 16, and the liquid phase outlet of the gas-liquid separator 14 is connected to the inlet of the transfer pump 15. The outlet of the transfer pump 15 is connected between the outlet of the oil-water separator 2 and the inlet of control valve A 301. Preferably, the cooler 13 uses a high-efficiency plate-fin or shell-and-tube heat exchanger; the gas-liquid separator 14 has built-in combined separation components, including a cyclone baffle and a high-efficiency wire mesh demister, to achieve efficient gas-liquid separation, with the amount of liquid droplets carried in the gas phase hydrocarbons after separation being less than 10 mg / Nm³. The transfer pump 15 is an anti-cavitation centrifugal pump, and the inlet of the transfer pump 15 is equipped with a liquid level interlock device, which automatically adjusts the pumping flow rate in response to changes in the liquid level of the gas-liquid separator 14 to maintain a stable liquid level and prevent pump cavitation.

[0024] The regeneration module includes a vaporizer 17, a flow control valve 18, and a heater 19 connected in series. The inlet of the vaporizer 17 is connected to the product outlet of the filter 8, and the outlet of the heater 19 is connected to the inlet of the L control valve 705. The heater 19 controls the fluid temperature at its outlet between 150℃ and 250℃. The flow control valve 18 regulates the flow rate through the heating channel 9 to account for 2% to 15% of the total outlet flow rate of the filter 8.

[0025] The inlet of filter 8 is connected between control valve H 701 and control valve I 702, and the exhaust outlet of filter 8 is connected to safety flare 16.

[0026] The inlet end of the counterflow channel 11 is connected to the outlet of the L control valve 705, and the outlet end of the counterflow channel 11 is connected to the inlet of the F control valve 306.

[0027] The specific working principle of this invention is as follows: In the initial stage, C3 to C6 hydrocarbon raw materials are introduced from the input port 1, passing through the oil-water separator 2 and the first valve group 3. At this time, the A control valve 301, G control valve 307 and D control valve 304 in the first valve group 3 are kept open, the H control valve 701, M control valve 706 and N control valve 707 in the second valve group 7 are kept open, and the remaining valves are kept closed. The raw materials pass through the first adsorption tower 5 and the second adsorption tower 6 respectively, and then through the corresponding valves of the second valve group 7, so that the fluids are all introduced from the inlet of the filter 8. After separation by the filter 8, the gas phase will flow to the safety flare 16, while the liquid phase will flow out from the output port, which is the final product. At this time, it is the state of dual tower adsorption. In the medium term, as time progresses, one of the first adsorption tower 5 and the second adsorption tower 6 will reach saturation first. By comparing the temperature difference value of the temperature sensor 20 in the same adsorption tower, it can be determined whether it is saturated (when saturated, water will condense into water droplets, and the temperature is low). Taking the second adsorption tower 6 reaching saturation first as an example, at this time, the A control valve 301, D control valve 304 and E control valve 305 in the first valve group 3 remain open, the H control valve 701, L control valve 705 and N control valve 707 in the second valve group 7 remain open, and the remaining valves remain closed. The on / off valve 12 on the counterflow channel 11 remains open. At this time, a part of the fluid passes through the heating channel 9, and this part of the fluid passes through the vaporizer 17, the flow control valve 18 and the heater 19, and then flows through the corresponding valves and into the second adsorption tower 6 for regeneration. This continues until the temperature difference value reflected by the temperature sensor 20 indicates that the second adsorption tower 6 has been regenerated (the temperature after regeneration is relatively high). At this time, the first adsorption tower 5 remains in the adsorption state, and the second adsorption tower 6 remains in the regeneration state. Later, in the first valve group 3, control valves A 301 and F 306 remain open, control valves H 701, J 703, K 704 and N 707 in the second valve group 7 remain open, and the remaining valves remain closed. The on / off valve 12 on the counterflow channel 11 remains open, so that some of the regenerated hydrocarbon hot gas passes through the return channel 4 and is cooled to the set temperature by the cooler 13. Then, it passes through the gas-liquid separator 14, allowing the gas phase to flow to the safety flare 16, and the liquid phase to be pumped to the outlet of the oil-water separator 2 by the transfer pump 15, and re-enter the system for recycling. After the hydrocarbon hot gas recovery is completed, the intelligent control module will switch each valve back to the previous state.

[0028] Similarly, when the first adsorption tower 5 reaches saturation in the middle stage, control valves B 302, C 303, D 304, and G 307 in the first valve group 3 remain open, control valves L 705 and M 706 in the second valve group 7 remain open, and the remaining valves remain closed. The on / off valve 12 on the counterflow channel 11 remains open. At this time, a portion of the fluid passes through the heating channel 9, allowing this portion of the fluid to pass through the vaporizer 17, flow control valve 18, and heater 19, and then through the corresponding valves to enter the first adsorption tower 5. At this time, the second adsorption tower 6 remains in the adsorption state, and the first adsorption tower 5 remains in the regeneration state. After the first adsorption tower 5 completes regeneration, it enters the later stage, and the first valve group... In valve 3, control valves D 304, F 306, and G 307 remain open. In valve group 7, control valves H 701, I 702, and M 706 remain open, while the remaining valves remain closed. The on / off valve 12 on the counterflow channel 11 remains open, allowing some of the regenerated hydrocarbon hot gas to pass through the return channel 4 and be cooled to the set temperature by the cooler 13. Then, it passes through the gas-liquid separator 14, allowing the gas phase to flow to the safety flare 16, while the liquid phase is pumped to the outlet of the oil-water separator 2 by the transfer pump 15, and re-enters the system for recycling. After the hydrocarbon hot gas recovery is completed, the intelligent control module will switch each valve back to its previous state.

[0029] In summary, the technical solution of this invention can fully and effectively achieve the above-mentioned objectives. Furthermore, the structure and functional principles of this invention have been fully verified in the embodiments, achieving the expected effects and objectives. Without departing from the principles and essence of this invention, various changes or modifications can be made to the embodiments. Therefore, this invention includes all substitutions within the scope mentioned in the patent application claims, and any equivalent changes made within the scope of this patent application are within the scope of the patent application.

Claims

1. A refining system of C3 to C6 hydrocarbons comprising an input port and an oil-water separator connected in sequence, the outlet of the oil-water separator being connected with a first valve group, characterized in that: The first valve group is respectively connected with a reflux channel, a first adsorption tower and a second adsorption tower, an outlet end of the reflux channel is connected between the first valve group and the oil-water separator, and a recovery module for cooling fluid is arranged on the reflux channel; An outlet of the first adsorption tower is connected with a second valve group, the second valve group is connected with an outlet of the second adsorption tower, the second valve group is connected with a filter, a product outlet of the filter is respectively connected with a heating channel and an output port, an outlet end of the heating channel is connected with the second valve group, and a regeneration module for heating fluid is arranged on the heating channel; A counterflow channel is connected between the first valve group and the second valve group, and an on-off valve is arranged on the counterflow channel.

2. The C3 to C6 refining system of claim 1, wherein: The first valve group comprises an A control valve, a B control valve, a C control valve, a D control valve, an E control valve, an F control valve and a G control valve, an inlet of the A control valve is connected with an outlet of the oil-water separator, and an outlet of the A control valve is connected with an inlet of the first adsorption tower; the inlet of the first adsorption tower is sequentially connected with the B control valve and the C control valve, an inlet of the second adsorption tower is sequentially connected with the D control valve and the E control valve; an inlet of the F control valve is respectively connected with an outlet of the C control valve and an outlet of the E control valve, and an outlet of the F control valve is connected with an inlet end of the reflux channel; an inlet of the G control valve is connected between the outlet of the oil-water separator and the inlet of the A control valve, and an outlet of the G control valve is connected between the inlet of the D control valve and the outlet of the E control valve.

3. The C3 to C6 refining system of claim 2, wherein: The second valve group comprises an H control valve, an I control valve, a J control valve, a K control valve, an L control valve, an M control valve and an N control valve, an outlet of the first adsorption tower is sequentially connected with the H control valve and the I control valve, and an outlet of the second adsorption tower is sequentially connected with the J control valve and the K control valve; an outlet of the L control valve is respectively connected with an inlet of the I control valve and an inlet of the K control valve, and an inlet of the L control valve is connected with an outlet end of the heating channel; an inlet of the M control valve is connected with an inlet of the second adsorption tower, and an outlet of the M control valve is connected with an inlet of the filter; an inlet of the N control valve is connected between the H control valve and the I control valve, and an outlet of the N control valve is connected between the inlet of the filter and the outlet of the M control valve.

4. The system for refining C3 to C6 as claimed in claim 3, wherein: The recovery module comprises a cooler, a gas-liquid separation tank and a delivery pump, an inlet of the cooler is connected with an outlet of the F control valve, an outlet of the cooler is connected with an inlet of the gas-liquid separation tank, a gas phase outlet of the gas-liquid separation tank is connected with a safety flare, a liquid phase outlet of the gas-liquid separation tank is connected with an inlet of the delivery pump, and an outlet of the delivery pump is connected between an outlet of the oil-water separator and the inlet of the A control valve.

5. The C3 to C6 refining system of claim 4, wherein: The regeneration module comprises a vaporizer, a flow control valve and a heater which are sequentially connected, an inlet of the vaporizer is connected with a product outlet of the filter, and an outlet of the heater is connected with an inlet of the L control valve.

6. The C3 to C6 refining system of claim 5, wherein: The heater controls the temperature of fluid at the outlet to be 150-250 DEG C.

7. The system for refining C3 to C6 as claimed in claim 5 wherein: The flow control valve regulates the flow rate through the heating channel to be 2%-15% of the total outlet flow rate of the filter.

8. The C3 to C6 refining system of claim 4, wherein: The filter inlet is connected between the H control valve and the I control valve, and the filter exhaust outlet is connected to the safety flare.

9. The system for refining C3 to C6 as claimed in claim 3, wherein: The inlet end of the counterflow channel is connected to the outlet of the L control valve, and the outlet end of the counterflow channel is connected to the inlet of the F control valve.

10. The C3 to C6 refining system of claim 1, wherein: Both the first adsorption tower and the second adsorption tower are equipped with a number of temperature sensors, which are spaced apart along the flow direction of the fluid.

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