A low-energy consumption prying type triethylene glycol dehydration tail gas zero discharge treatment device

Abstract

This invention discloses a low-energy skid-mounted zero-emission treatment device for triethylene glycol dehydration tail gas, comprising a tail gas cooling unit, a gas-liquid separation unit, and a tail gas recovery and utilization unit connected in sequence. The gas-liquid separation unit includes a gas-liquid separation tank with a gas output pipe. The tail gas recovery and utilization unit has a tail gas input pipe, which is connected to the tail gas input pipe. The tail gas input pipe is also connected to a dynamite natural gas output pipe. An ejector is installed at the connection between the dynamite natural gas output pipe and the tail gas input pipe to transport the tail gas along with natural gas to the downstream end of the main natural gas pipeline. The beneficial effects of this invention are that by mixing the regenerated tail gas after gas-liquid separation with pressurized dynamite natural gas under the action of the ejector, and then transporting the tail gas to the downstream end of the main natural gas pipeline, the tail gas can be recovered and reused, improving economic efficiency, achieving zero tail gas emissions, and preventing environmental pollution.

Description

Technical Field

[0001] This invention relates to a technology for treating triethylene glycol tail gas, and in particular to a low-energy skid-mounted zero-emission treatment device for triethylene glycol dehydration tail gas. Background Technology

[0002] Because natural gas contains components such as hydrogen sulfide and light hydrocarbons, during the natural gas dehydration process, natural gas comes into contact with a triethylene glycol solution. The hydrogen sulfide and light hydrocarbons in the natural gas dissolve in the triethylene glycol solution. The flash vapor and regeneration tail gas generated during the triethylene glycol dehydration process contain various heavy hydrocarbons and other pollutants. These gases cannot be directly discharged into the atmosphere and must be treated. Only after the treated gases meet the standards can they be directly discharged into the atmosphere.

[0003] Currently, the flash vapor and regeneration tail gas generated during the dehydration of triethylene glycol are mainly treated by the incineration method. The flash vapor and regeneration tail gas are incinerated in an incinerator. The incineration method causes significant environmental pollution, consumes a lot of fuel gas, and has high operating costs. Summary of the Invention

[0004] The purpose of this invention is to provide a low-energy-consumption skid-mounted zero-emission treatment device for triethylene glycol dehydration tail gas. The regenerated tail gas is injected into the main natural gas pipeline for recovery, replacing the combustion method for tail gas treatment, reducing treatment costs, improving economic efficiency, and achieving zero tail gas emissions. To achieve the above objective, this invention adopts the following technical solution.

[0005] A low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device includes a tail gas cooling unit, a gas-liquid separation unit, and a tail gas recovery and utilization unit connected in sequence. The gas-liquid separation unit includes a gas-liquid separation tank with a gas output pipe. The tail gas recovery and utilization unit has a tail gas input pipe. The gas output pipe is connected to the tail gas input pipe, and the tail gas input pipe is also connected to a dynamite natural gas output pipe. An ejector is installed at the connection between the dynamite natural gas output pipe and the tail gas input pipe to transport the tail gas together with natural gas to the downstream end of the main natural gas pipeline.

[0006] The present invention, employing the aforementioned technical solution, by setting up a tail gas cooling unit, a gas-liquid separation unit, and a tail gas recovery and utilization unit connected in sequence, facilitates the precipitation of condensate from the tail gas after condensation in the tail gas cooling unit, facilitates gas-liquid separation of liquid water in the gas-liquid separation unit, and sets up a gas-liquid separation tank in the gas-liquid separation unit. The gas-liquid separation tank further separates the tail gas containing a small amount of water mist after passing through the heat exchanger. The gas output pipe of the gas-liquid separation tank is connected to the tail gas input pipe of the tail gas recovery and utilization unit, and is also connected to the kinetic natural gas output pipe. This facilitates the mixing of the tail gas after gas-liquid separation with pressurized kinetic natural gas under the action of the ejector, and facilitates the transportation of the tail gas and natural gas together to the downstream end of the main natural gas pipeline for recycling. This replaces the combustion method for treating tail gas, reduces treatment costs, improves economic efficiency through tail gas recycling, achieves zero tail gas emissions, and prevents environmental pollution from combustion tail gas.

[0007] Preferably, the exhaust gas cooling unit includes a heat exchanger, a triethylene glycol flash vapor output pipe and a triethylene glycol distillation exhaust gas output pipe that are combined to form a mixed gas of triethylene glycol flash vapor and triethylene glycol distillation exhaust gas. The mixed gas enters the cooling channel of the heat exchanger, condenses, and is then output to the gas-liquid separation unit.

[0008] In this way, by merging the triethylene glycol flash vapor output pipe and the triethylene glycol distillation tail gas output pipe, the triethylene glycol flash vapor and triethylene glycol distillation tail gas are mixed into a gas mixture. The mixed gas is then cooled in the cooling channel of the heat exchanger, and condensate is released after the mixed gas condenses, thus achieving the first gas-liquid separation. The liquid and gas are then output to the gas-liquid separation unit.

[0009] Preferably, a flow meter and a check valve are installed on both the triethylene glycol flash vapor output pipe and the triethylene glycol distillation tail gas output pipe, and a flow meter is installed on the tail gas input pipe.

[0010] This makes it easy to detect the amount of exhaust gas generated and the exhaust gas output flow rate through a flow meter, and to install a one-way valve to prevent the gas from flowing back after condensation.

[0011] Preferably, the outlet of the heat exchanger is inclined downwards.

[0012] This design, with the heat exchanger outlet tilted downwards, facilitates the smooth flow of liquid water into the gas-liquid separation unit.

[0013] Preferably, the heat exchanger is connected to the circulating water pipeline via a pipe.

[0014] In this way, by connecting the heat exchanger to the circulating water pipe, it is convenient to condense the exhaust gas through the cold water in the circulating water pipe.

[0015] Preferably, the gas-liquid separation unit further includes a separator, the inlet of which is connected to a separator input pipe and the outlet of which is connected to a separator output pipe. The separator input pipe is connected to the output pipe of the heat exchanger, and the separator output pipe is connected to the sewage discharge network.

[0016] In this way, by setting up a separator and connecting the separator's inlet pipe to the heat exchanger's outlet pipe, and connecting the separator's outlet pipe to the wastewater network, the condensate flowing out of the heat exchanger's outlet pipe can enter the separator for treatment and then be discharged to the wastewater network through the separator's outlet pipe.

[0017] Preferably, the gas-liquid separator and the liquid separator are connected in parallel, and a one-way valve is connected to both the liquid separator inlet pipe and the liquid separator outlet pipe. The gas-liquid separator has a separator inlet pipe at its inlet, which is connected to the heat exchanger outlet pipe, and a one-way valve is installed on the separator inlet pipe.

[0018] In this way, the gas-liquid separator and the liquid separator are connected in parallel to achieve automatic switching. One-way valves are connected to both the inlet and outlet pipes of the liquid separator. When the liquid separator is draining, the one-way valves can close the inlet pipes of both the gas-liquid separator and the liquid separator to prevent negative pressure from forming in the liquid separator and causing backflow of alcohol.

[0019] Preferably, the gas-liquid separator has two outlets, each connected to a liquid output pipe and a gas output pipe respectively. The liquid output pipe is connected to the sewage discharge network, and the gas output pipe is connected to the exhaust gas input pipe.

[0020] In this way, two outlets will be set in the gas-liquid separator. The inlet pipe of the separator is connected to the outlet pipe of the heat exchanger, and the liquid outlet pipe is connected to the sewage network. This makes it easy for the separated liquid to be discharged to the sewage network through the liquid outlet pipe under the action of the gas-liquid separator, and the separated gas to be transported to the tail gas inlet pipe through the gas outlet pipe for the next process.

[0021] Preferably, a branch pipe is formed on the gas output pipe, and the branch pipe is connected to the outlet of the separator.

[0022] By creating a branch pipe on the gas output pipe that connects to the outlet of the separator, it is convenient for the separated liquid to be processed through the separator.

[0023] Preferably, a one-way valve is connected to one end of the exhaust gas input pipe near the gas-liquid separation unit, and a safety valve is connected to one end near the power natural gas output pipe. The one-way valve and the safety valve divide the exhaust gas input pipe into a low-pressure zone and a high-pressure zone. A flow meter is installed at the end of the safety valve near the diverter.

[0024] In this way, by connecting a check valve to one end of the exhaust gas inlet pipe near the gas-liquid separation unit and a safety valve to the other end near the power natural gas outlet pipe, the check valve and safety valve can easily divide the exhaust gas inlet pipe into a low-pressure zone and a high-pressure zone, and prevent natural gas from the high-pressure zone from entering the exhaust gas treatment unit in the low-pressure zone, thus ensuring the safety of the device during use.

[0025] The beneficial effects of this invention are that by setting up a tail gas cooling unit, a gas-liquid separation unit, and a tail gas recovery and utilization unit connected in sequence, it is convenient to condense water from the tail gas after condensation in the tail gas cooling unit, facilitate preliminary gas-liquid separation of liquid water in the gas-liquid separation unit, and set up a gas-liquid separation tank in the gas-liquid separation unit to further separate the tail gas with a small amount of water mist after passing through the heat exchanger. A liquid separator is set up to treat the separated and condensed liquid before it is discharged to the pollutant pipeline network. The gas output pipe of the gas-liquid separation tank is connected to the tail gas input pipe of the tail gas recovery and utilization unit, and the tail gas input pipe is also connected to the power natural gas output pipe. This facilitates the mixing of the tail gas after gas-liquid separation with pressurized power natural gas under the action of the ejector, and facilitates the transportation of tail gas and natural gas together to the downstream end of the main natural gas pipeline. This replaces the combustion method for tail gas treatment, reduces treatment costs, improves economic efficiency by recycling tail gas, and achieves zero tail gas emissions to prevent environmental pollution. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the present invention;

[0027] Figure 2 This is a schematic diagram of the exhaust gas cooling unit of the present invention;

[0028] Figure 3 This is a schematic diagram of the gas-liquid separation unit of the present invention;

[0029] Figure 4 This is a schematic diagram of the exhaust gas recovery and utilization unit of the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings, but this does not limit the invention to the scope of the embodiments described.

[0031] The reference numerals in the accompanying drawings include: exhaust gas cooling unit 1, flow meter 101, heat exchanger 102, gas-liquid separation unit 2, liquid separator 201, gas-liquid separator 202, exhaust gas recovery and utilization unit 3, safety valve 301, one-way valve 302, and ejector 303.

[0032] Example 1, see Figures 1 to 4A low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device includes a tail gas cooling unit 1, a gas-liquid separation unit 2, and a tail gas recovery and utilization unit 3 connected in sequence. The gas-liquid separation unit 2 includes a gas-liquid separation tank 202 with a gas output pipe. The tail gas recovery and utilization unit 3 has a tail gas input pipe. The gas output pipe is connected to the tail gas input pipe. The tail gas input pipe is also connected to a dynamite natural gas output pipe. An ejector 303 is installed at the connection between the dynamite natural gas output pipe and the tail gas input pipe to transport the tail gas together with the natural gas to the downstream end of the main pipeline natural gas.

[0033] See Figure 1 and Figure 2 The exhaust gas cooling unit 1 includes a heat exchanger 102, a triethylene glycol flash vapor output pipe, and a triethylene glycol distillation exhaust gas output pipe that converge to form a mixed gas mixture of triethylene glycol flash vapor and triethylene glycol distillation exhaust gas. This mixed gas enters the cooling channel of the heat exchanger 102, condenses, and is then output to the gas-liquid separation unit 2. In this way, the triethylene glycol flash vapor and triethylene glycol distillation exhaust gas are mixed, and the mixed gas is cooled in the cooling channel of the heat exchanger 102, causing condensate to precipitate and achieving gas-liquid separation. The liquid and gas are then output to the gas-liquid separation unit 2. Preferably, the heat exchanger 102 in this invention is a swept-back tube heat exchanger 102, employing forced air cooling or forced water cooling to cool the regenerated exhaust gas within the tubes.

[0034] See Figure 1 Flow meters 101 and check valves 302 are respectively installed on the triethylene glycol flash vapor output pipeline and the triethylene glycol distillation tail gas output pipeline. A flow meter 101 is installed on the end of the safety valve 301 near the inlet. The three flow meters 101 facilitate the detection of the regeneration tail gas generation and the flow rate of the regeneration tail gas after cooling and separation. See also... Figure 2 The outlet of the heat exchanger 102 is inclined downwards to facilitate the smooth flow of liquid water into the gas-liquid separation unit 2.

[0035] join Figure 2 The heat exchanger 102 is connected to the circulating water pipeline via a pipe.

[0036] See Figure 1 and Figure 3 The gas-liquid separation unit 2 further includes a liquid separator 201. The inlet of the liquid separator 201 is connected to an input pipe, and the outlet is connected to an output pipe. The input pipe is connected to the output pipe of the heat exchanger 102, and the output pipe is connected to the wastewater network. Preferably, a horizontal liquid separator 201 is used, with a collection bag at the bottom for periodic recovery using a centrifugal pump.

[0037] See Figure 3 The gas-liquid separator 202 and the liquid separator 201 are connected in parallel (meaning their input and output pipes are connected in parallel). A one-way valve 302 is connected to both the input and output pipes of the liquid separator 201. The gas-liquid separator 202 has an inlet pipe and two outlets, connected to a liquid outlet pipe and a gas outlet pipe respectively. The inlet pipe connects to the output pipe of the heat exchanger 102, the liquid outlet pipe connects to the wastewater network, and the gas outlet pipe connects to the exhaust gas inlet pipe. The liquid separator 201 can employ high-efficiency internal components (inlet vortex deflector, inclined rectifier separation plate assembly, agglomerated packing, etc.) to increase the throughput of the unit and reduce the overall size of the equipment.

[0038] See Figure 1 and Figure 3 A branch pipe is formed on the gas output pipe, and the branch pipe is connected to the outlet of the liquid separator 201.

[0039] See Figure 1 and Figure 4 The exhaust gas input pipe is connected to a one-way valve 302 at one end near the gas-liquid separation unit 2 and a safety valve 301 at the other end near the power natural gas output pipe. The one-way valve 302 and the safety valve 301 divide the exhaust gas input pipe into a low-pressure zone and a high-pressure zone.

[0040] This invention adopts a skid-mounted design. Through optimized arrangement, the skid structure is compact, which facilitates operation and transportation. At the same time, the components are optimized to reduce the overall weight of the equipment.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device, comprising a tail gas cooling unit (1), a gas-liquid separation unit (2) and a tail gas recovery and utilization unit (3) connected in sequence, wherein the gas-liquid separation unit (2) includes a gas-liquid separation tank (202) having a gas output pipe, the tail gas recovery and utilization unit (3) having a tail gas input pipe, the gas output pipe being connected to the tail gas input pipe, the tail gas input pipe also being connected to a dynamite natural gas output pipe, and an ejector (303) being installed at the connection between the dynamite natural gas output pipe and the tail gas input pipe to transport the tail gas together with natural gas to the downstream end of the main pipeline natural gas; The gas-liquid separation unit (2) further includes a liquid separator (201), the inlet of which is connected to a liquid separator (201) input pipe and the outlet of which is connected to a liquid separator (201) output pipe. The liquid separator (201) input pipe is connected to the output pipe of the heat exchanger (102), and the liquid separator (201) output pipe is connected to the sewage pipe network. The gas-liquid separator (202) and the liquid separator (201) are connected in parallel. The gas-liquid separator (202) has a separator input pipe at its inlet, which is connected to the output pipe of the heat exchanger (102). The gas-liquid separator (202) has two outlets, which are respectively connected to a liquid output pipe and a gas output pipe. The liquid output pipe is connected to the sewage pipe network, and the gas output pipe is connected to the tail gas input pipe. A branch pipe is formed on the gas output pipe, and the branch pipe is connected to the outlet of the separator (201).

2. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 1, characterized in that, The tail gas cooling unit (1) includes a heat exchanger (102), a triethylene glycol flash vapor output pipe and a triethylene glycol distillation tail gas output pipe that are combined to form a mixed gas of triethylene glycol flash vapor and triethylene glycol distillation tail gas. The mixed gas enters the cooling channel of the heat exchanger (102), condenses, and is then output to the gas-liquid separation unit (2).

3. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 2, characterized in that, A flow meter (101) and a one-way valve (302) are respectively installed on the triethylene glycol flash vapor output pipe and the triethylene glycol distillation tail gas output pipe, and a flow meter (101) is installed on the tail gas input pipe.

4. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 2, characterized in that, The outlet of the heat exchanger (102) is inclined downward.

5. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 2, characterized in that, The heat exchanger (102) is connected to the circulating water pipeline via a pipe.

6. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 1, characterized in that, One-way valves (302) are connected to both the inlet pipe and the outlet pipe of the separator (201), and a one-way valve (302) is installed on the inlet pipe of the separator.

7. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 1, characterized in that, The exhaust gas input pipe is connected to a one-way valve (302) at one end near the gas-liquid separation unit (2), and a safety valve (301) at the other end near the power natural gas output pipe. The one-way valve (302) and the safety valve (301) divide the exhaust gas input pipe into a low-pressure zone and a high-pressure zone.

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