Low-energy-consumption skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device

Abstract

The invention discloses a low-energy-consumption skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device which comprises a tail gas cooling unit, a gas-liquid separation unit and a tail gas recycling unit which are connected in sequence, the gas-liquid separation unit comprises a gas-liquid separation tank, the gas-liquid separation tank is provided with a gas output pipe, and the gas output pipe is connected with the tail gas cooling unit. The tail gas recycling unit is provided with a tail gas input pipeline, the gas output pipe is communicated with the tail gas input pipeline, the tail gas input pipeline is further communicated with the power natural gas output pipeline, and an ejector is installed at the joint of the power natural gas output pipeline and the tail gas input pipeline. Tail gas and natural gas are conveyed to the rear end of the natural gas of the main pipeline. The system has the beneficial effects that regenerated tail gas after gas-liquid separation is mixed with power natural gas with pressure under the action of the ejector, and the tail gas is conveyed to the rear end of the natural gas of the main pipeline, so that the tail gas is recycled, the economic benefit is improved, zero emission of the tail gas is realized, and the environment is prevented from being polluted.

Description

Technical Field

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

[0002] Since natural gas contains components such as hydrogen sulfide and light hydrocarbons, during the natural gas dehydration process, natural gas and triethylene glycol solution come into contact, and components such as hydrogen sulfide and light hydrocarbons in natural gas are dissolved in the triethylene glycol solution. The flash gas and regenerated tail gas generated during the triethylene glycol dehydration process contain a variety of heavy hydrocarbons and other pollutants. This part of the gas cannot be discharged directly into the atmosphere and must be treated. Only after the treated gas is qualified can it be directly discharged into the air.

[0003] At present, the flash steam and regeneration tail gas generated in the dehydration process of triethylene glycol are mainly treated by the incineration method. The flash steam and regeneration tail gas are incinerated in an incineration furnace. The incineration method has a large environmental pollution, large fuel gas consumption and high operating cost. Summary of the invention

[0004] The purpose of the present invention is to provide a low-energy skid-mounted triethylene glycol dehydration tail gas zero emission treatment device, in which the regenerated tail gas is injected into the natural gas main pipeline for recovery, replacing the incineration method to treat the tail gas, reducing the treatment cost, improving the economic benefit, and achieving zero tail gas emission.

[0005] To achieve the above purpose, the present invention adopts the following technical solution.

[0006] A low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device comprises a tail gas cooling unit, a gas-liquid separation unit and a tail gas recovery unit connected in sequence, the gas-liquid separation unit comprises a gas-liquid separation tank, the gas-liquid separation tank has a gas output pipe, the tail gas recovery unit has a tail gas input pipeline, the gas output pipe is connected to the tail gas input pipeline, the tail gas input pipeline is also connected to the power natural gas output pipeline, and an ejector is installed at the connection between the power natural gas output pipeline and the tail gas input pipe to transport the tail gas together with the natural gas to the rear end of the main natural gas pipeline.

[0007] The present invention adopts the above-mentioned technical scheme, by setting up a tail gas cooling unit, a gas-liquid separation unit and a tail gas recovery unit connected in sequence, so that it is convenient to precipitate condensed water from the tail gas after condensation through the tail gas cooling unit, and to separate the liquid water into gas and liquid in the gas-liquid separation unit, and a gas-liquid separation tank is set in the gas-liquid separation unit, and the tail gas with a small amount of water mist after passing through the heat exchanger is further separated into gas and liquid through the gas-liquid separation tank, and the gas output pipe of the gas-liquid separation tank is connected with the tail gas input pipeline of the tail gas recovery unit, and the tail gas input pipeline is also connected with the power natural gas output pipeline, so that the tail gas after gas-liquid separation is mixed with the pressurized power natural gas under the action of the ejector, and the tail gas is transported together with the natural gas to the rear end of the main line natural gas for recycling again, instead of the incineration method to treat the tail gas, reduce the treatment cost, and improve the economic benefits by recycling the tail gas, and achieve zero emission of tail gas, and prevent the combustion of tail gas from polluting the environment.

[0008] Preferably, the tail gas cooling unit includes a heat exchanger, and the triethylene glycol flash gas output pipeline and the triethylene glycol distillation tail gas output pipeline are merged, so that the triethylene glycol flash gas and the triethylene glycol distillation tail gas form a mixed gas, and the mixed gas enters the cooling channel of the heat exchanger, condenses, and is output to the gas-liquid separation unit.

[0009] In this way, by merging the triethylene glycol flash gas output pipeline and the triethylene glycol distillation tail gas output pipeline, the triethylene glycol flash gas and the triethylene glycol distillation tail gas form a mixed gas, and the mixed gas enters the cooling channel of the heat exchanger for cooling, so that the mixed gas precipitates condensed water after condensation, realizes the first gas-liquid separation, and outputs the liquid and gas to the gas-liquid separation unit.

[0010] Preferably, the triethylene glycol flash gas output pipeline and the triethylene glycol distillation tail gas output pipeline are respectively installed with a flow meter and a one-way valve, and the tail gas input pipeline is installed with a flow meter.

[0011] In this way, it is convenient to detect the exhaust gas generation amount and exhaust gas output flow rate through the flow meter, and a one-way valve is set to prevent the gas from flowing back after condensation.

[0012] Preferably, the outlet of the heat exchanger is arranged to be inclined downward.

[0013] In this way, the outlet of the heat exchanger is tilted downward to facilitate the liquid water to flow out smoothly into the gas-liquid separation unit.

[0014] Preferably, the heat exchanger is connected to the circulating water pipeline through a pipeline.

[0015] In this way, by connecting the heat exchanger to the circulating water pipeline through the pipeline, it is convenient to condense the exhaust gas through the cold water in the circulating water pipeline.

[0016] Preferably, the gas-liquid separation unit also includes a liquid separator tank, the inlet of the liquid separator tank is connected to a liquid separator tank input pipe, the outlet is connected to a liquid separator tank output pipe, the liquid separator tank input pipe is connected to an output pipe of a heat exchanger, and the liquid separator tank output pipe is connected to a sewage pipe network.

[0017] In this way, by setting up a separatory tank and connecting the separatory tank input pipe of the separatory tank with the output pipe of the heat exchanger, and connecting the separatory tank output pipe with the sewage network, it is convenient for the condensed water flowing out of the output pipe of the heat exchanger to enter the separatory tank for treatment, and then be discharged to the sewage network through the separatory tank output pipe.

[0018] Preferably, the gas-liquid separation tank and the liquid separator tank are connected in parallel, and a one-way valve is connected to both the liquid separator tank input pipe and the liquid separator tank output pipe. The inlet of the gas-liquid separation tank has a separation tank input pipe, and the separation tank input pipe is connected to the output pipe of the heat exchanger, and a one-way valve is installed on the separation tank input pipe.

[0019] In this way, the gas-liquid separation tank and the liquid separator tank are connected in parallel to realize automatic switching, and a one-way valve is connected to the input pipe and the output pipe of the liquid separator tank. When the liquid separator tank is drained, the input pipe of the gas-liquid separation tank and the input pipe of the liquid separator tank are closed through the one-way valve to prevent negative pressure from being generated in the liquid separator tank and causing alcohol reflux.

[0020] Preferably, the gas-liquid separation tank is provided with two outlets, and the two outlets are respectively connected to a liquid output pipe and a gas output pipe, the liquid output pipe is connected to a sewage pipe network, and the gas output pipe is connected to the tail gas input pipe.

[0021] In this way, two outlets of the gas-liquid separation tank are set, the separation tank input pipe is connected to the output pipe of the heat exchanger, and the liquid output pipe is connected to the sewage network, so that the separated liquid can be discharged to the sewage network through the liquid output pipe under the action of the gas-liquid separation tank, and the separated gas can be transported to the exhaust gas input pipe through the gas output pipe for the next process.

[0022] Preferably, a branch pipe is formed on the gas output pipe, and the branch pipe is connected to the inlet of the liquid separation tank.

[0023] In this way, a branch pipe is formed on the gas output pipe and connected to the inlet of the liquid separator, so that the separated part of the liquid can be processed through the liquid separator.

[0024] Preferably, the end of the exhaust gas input pipeline close to the gas-liquid separation unit is connected to a one-way valve, and the end close to the power natural gas output pipe is connected to a safety valve, and the exhaust gas input pipeline is divided into a low-pressure area and a high-pressure area by the one-way valve and the safety valve; the end of the safety valve close to the diverter is installed with a flow meter.

[0025] In this way, by connecting a one-way valve to the end of the exhaust gas input pipeline close to the gas-liquid separation unit and a safety valve to the end close to the power natural gas output pipe, the one-way valve and the safety valve can divide the exhaust gas input pipeline into a low-pressure area and a high-pressure area, and prevent the natural gas in the high-pressure area from entering the exhaust gas treatment unit in the low-pressure area, thereby ensuring the safety of the device during use.

[0026] The beneficial effect of the present invention is that, by setting up a tail gas cooling unit, a gas-liquid separation unit and a tail gas recovery unit connected in sequence, it is convenient to precipitate condensed water from the tail gas after condensation through the tail gas cooling unit, and it is convenient to perform preliminary gas-liquid separation of liquid water in the gas-liquid separation unit, and a gas-liquid separation tank is set in the gas-liquid separation unit, and the tail gas with a small amount of water mist after passing through the heat exchanger is further separated into gas and liquid through the gas-liquid separation tank, and a liquid separator is set to treat the separated and condensed liquid, and then discharge it to the pollutant pipe network, and the gas output pipe of the gas-liquid separation tank is connected to the tail gas input pipeline of the tail gas recovery unit, and the tail gas input pipeline is also connected to the power natural gas output pipeline, so that the tail gas after gas-liquid separation is mixed with the pressurized power natural gas under the action of the ejector, and the tail gas is transported to the rear end of the main line natural gas together with the natural gas, instead of the incineration method to treat the tail gas, reduce the treatment cost, and improve the economic benefit by recycling the tail gas, and achieve zero tail gas emission to prevent environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the present invention;

[0028] Figure 2 is a schematic diagram of the tail gas cooling unit of the present invention;

[0029] Figure 3 is a schematic diagram of a gas-liquid separation unit of the present invention;

[0030] Figure 4 It is a schematic diagram of the tail gas recovery and utilization unit of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the described embodiments.

[0032] The figure marks in the drawings of the specification include: exhaust gas cooling unit 1, flow meter 101, heat exchanger 102, gas-liquid separation unit 2, liquid separator 201, gas-liquid separation tank 202, exhaust gas recovery unit 3, safety valve 301, one-way valve 302, ejector 303.

[0033] Example 1, see Figures 1 to 4A low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device comprises a tail gas cooling unit 1, a gas-liquid separation unit 2 and a tail gas recovery unit 3 which are connected in sequence, wherein the gas-liquid separation unit 2 comprises a gas-liquid separation tank 202, wherein the gas-liquid separation tank 202 has a gas output pipe, and the tail gas recovery unit 3 has a tail gas input pipeline, wherein the gas output pipe is communicated with the tail gas input pipeline, and the tail gas input pipeline is also communicated with the power natural gas output pipeline, and an ejector 303 is installed at the connection between the power natural gas output pipeline and the tail gas input pipeline to transport the tail gas together with the natural gas to the rear end of the main natural gas pipeline.

[0034] See also Figure 1 and Figure 2 The tail gas cooling unit 1 includes a heat exchanger 102, and the triethylene glycol flash gas output pipeline and the triethylene glycol distillation tail gas output pipeline are merged, so that the triethylene glycol flash gas and the triethylene glycol distillation tail gas form a mixed gas, and the mixed gas enters the cooling channel of the heat exchanger 102 for condensation and is output to the gas-liquid separation unit 2. In this way, the triethylene glycol flash gas and the triethylene glycol distillation tail gas form a mixed gas, and the mixed gas enters the cooling channel of the heat exchanger 102 for cooling, so that the mixed gas precipitates condensed water after condensation, realizes gas-liquid separation, and outputs the liquid and gas to the gas-liquid separation unit 2. The heat exchanger 102 in the present invention is preferably a horizontal swept tube heat exchanger 102, and the regenerated tail gas in the tube is cooled by forced air cooling or forced water cooling.

[0035] See also Figure 1 , the triethylene glycol flash gas output pipeline and the triethylene glycol distillation tail gas output pipeline are respectively installed with a flow meter 101 and a one-way valve 302. The safety valve 301 is installed with a flow meter 101 at one end close to the flow guide. The three flow meters 101 are arranged to facilitate the detection of the amount of regenerated tail gas generated and the flow of the regenerated tail gas after cooling and separation. Figure 2 The outlet of the heat exchanger 102 is tilted downward to facilitate the liquid water to flow out smoothly into the gas-liquid separation unit 2.

[0036] join Figure 2 , the heat exchanger 102 is connected to the circulating water pipeline through a pipeline.

[0037] See also Figure 1 and Figure 3 The gas-liquid separation unit 2 further comprises a liquid separator 201, the inlet of the liquid separator 201 is connected to an input pipe of the liquid separator 201, the outlet is connected to an output pipe of the liquid separator 201, the input pipe of the liquid separator 201 is connected to the output pipe of the heat exchanger 102, and the output pipe of the liquid separator 201 is connected to the sewage pipe network. It is best to use a horizontal liquid separator 201, set a liquid collection bag at the bottom of the liquid separator 201, and use a centrifugal pump to regularly recover.

[0038] See also Figure 3 , the gas-liquid separation tank 202 and the liquid separator 201 are connected in parallel (meaning that the input pipe and output pipe of the gas-liquid separation tank 202 and the liquid separator 201 form a parallel connection relationship), and the input pipe of the liquid separator 201 and the output pipe of the liquid separator 201 are both connected with a one-way valve 302. The inlet of the gas-liquid separation tank 202 has a separation tank input pipe, and the gas-liquid separation tank 202 is provided with two outlets, and the two outlets are respectively connected with a liquid output pipe and a gas output pipe, the separation tank input pipe is connected to the output pipe of the heat exchanger 102, the liquid output pipe is connected to the sewage pipe network, and the gas output pipe is connected to the tail gas input pipe. The liquid separator 201 can use efficient separation internals (inlet rotator, inclined rectifier separation plate group, aggregation filler, etc.) to increase the processing capacity of the unit volume of the equipment and reduce the volume of the equipment.

[0039] See also Figure 1 and Figure 3 A branch pipe is formed on the gas output pipe, and the branch pipe is connected to the inlet of the liquid separation tank 201.

[0040] See also Figure 1 and Figure 4 The end of the tail gas input pipeline close to the gas-liquid separation unit 2 is connected to a one-way valve 302, and the end close to the power natural gas output pipe is connected to a safety valve 301. The one-way valve 302 and the safety valve 301 divide the tail gas input pipeline into a low-pressure area and a high-pressure area.

[0041] The present invention adopts a skid design, and through optimized layout, the skid structure is compact, easy to operate and transport, while accessories are optimized to reduce the total weight of the equipment.

[0042] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A low-energy skid-mounted triethylene glycol dehydration tail gas zero emission treatment device, characterized in that: The invention comprises an exhaust gas cooling unit (1), a gas-liquid separation unit (2) and an exhaust gas recovery unit (3) which are connected in sequence, wherein the gas-liquid separation unit (2) comprises a gas-liquid separation tank (202), the gas-liquid separation tank (202) has a gas output pipe, and the exhaust gas recovery unit (3) has an exhaust gas input pipeline, the gas output pipe is connected to the exhaust gas input pipeline, the exhaust gas input pipeline is also connected to the power natural gas output pipeline, and an ejector (303) is installed at the connection between the power natural gas output pipeline and the exhaust gas input pipeline to transport the exhaust gas together with the natural gas to the natural gas rear end of the main pipeline.

2. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 1 is characterized in that: The tail gas cooling unit (1) comprises a heat exchanger (102), a triethylene glycol flash gas output pipeline and a triethylene glycol distillation tail gas output pipeline are merged, so that the triethylene glycol flash gas and the triethylene glycol distillation tail gas form a mixed gas, and the mixed gas enters the cooling channel of the heat exchanger (102) to be condensed and 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 is characterized in that: The triethylene glycol flash gas output pipeline and the triethylene glycol distillation tail gas output pipeline are respectively installed with a flow meter (101) and a one-way valve (302), and the tail gas input pipeline is installed with a flow meter (101).

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

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

6. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 1 is characterized in that: The gas-liquid separation unit (2) further comprises a liquid separation tank (201), the inlet of the liquid separation tank (201) being connected to an input pipe of the liquid separation tank (201), and the outlet being connected to an output pipe of the liquid separation tank (201), the input pipe of the liquid separation tank (201) being connected to an output pipe of the heat exchanger (102), and the output pipe of the liquid separation tank (201) being connected to a sewage pipe network.

7. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 6 is characterized in that: The gas-liquid separation tank (202) and the liquid separator tank (201) are connected in parallel, and a one-way valve (302) is connected to both the liquid separator tank (201) input pipe and the liquid separator tank (201) output pipe. The inlet of the gas-liquid separation tank (202) has a separation tank input pipe, and the separation tank input pipe is connected to the output pipe of the heat exchanger (102). The separation tank input pipe is installed with a one-way valve (302).

8. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 1 is characterized in that: The gas-liquid separation tank (202) is provided with two outlets, and the two outlets 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 pipeline.

9. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 8, characterized in that: A branch pipe is formed on the gas output pipe, and the branch pipe is connected to the inlet of the liquid separation tank (201).

10. The low-energy skid-mounted triethylene glycol dehydration tail gas zero-emission treatment device according to claim 1 is characterized in that: One end of the tail gas input pipeline close to the gas-liquid separation unit (2) is connected to a one-way valve (302), and one end close to the power natural gas output pipe is connected to a safety valve (301), and the tail gas input pipeline is divided into a low-pressure area and a high-pressure area by the one-way valve (302) and the safety valve (301).

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