Sulfur-containing natural gas purification tail gas treatment device

Abstract

The utility model provides a sulfur-containing natural gas purification tail gas treatment device. The sulfur-containing natural gas purification tail gas treatment device comprises a first heater, a reactor and a sulfur condenser which are connected in sequence, the inlet end of the first heater is connected with a tail gas source, and the upstream and / or downstream of the first heater is connected with an air input pipeline; the reactor is used for inputting mixed gas formed by tail gas and air; the sulfur condenser is provided with a second heat exchange pipeline and is used for cooling a product output by the reactor to separate elemental sulfur; the input end of the first heat exchange pipeline and the output end of the second heat exchange pipeline are connected with a high-temperature medium pipeline, and the output end of the first heat exchange pipeline and the input end of the second heat exchange pipeline are connected with a low-temperature medium pipeline. Based on the technical scheme of the utility model, tail gas and air are mixed for catalytic reaction, residual H2S in the tail gas can be converted into elemental sulfur, and heat required in the whole treatment process can be recycled, so that sulfur in the tail gas can be further recycled, and high efficiency and energy conservation can be realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to natural gas purification tail gas treatment technical field, especially a kind of sulfur-containing natural gas purification tail gas treatment device. BACKGROUND

[0002] In the field of small-scale high-sulfur natural gas purification (processing capacity ≤500,000 cubic meters / day, H2S content >2%), during the natural gas purification process, the desulfurizer can absorb H2S, CO2 and other acidic substances in the raw natural gas, and release H2S-containing acidic gas after regeneration. This part of the acidic gas contains a large amount of H2S, and sulfur recovery has great economic benefits.

[0003] The process technology of sulfur recovery currently usually adopts improved Claus (also known as conventional Claus) process to recover elemental sulfur from acidic gas. Compared with other sulfur recovery processes, the improved Claus process is the most efficient, least investment and most mature method for recovering elemental sulfur from acidic gas in the field of natural gas purification.

[0004] When recovering elemental sulfur from acidic gas using the improved Claus method, since the Claus reaction is reversible and limited by chemical equilibrium, even with a 4-stage converter, the total sulfur recovery rate can only reach 98%-99%, and 1%-2% of sulfides still need to be discharged into the atmosphere.

[0005] At the same time, when the Claus reaction converter exceeds 2 stages, the use cost increases significantly, so the Claus reaction is usually 2 stages. However, the sulfur recovery under the 2-stage Claus process is limited, with a recovery rate of about 95%, and the remaining Claus tail gas cannot be discharged up to standard. SUMMARY

[0006] To solve the problem of non-compliance of tail gas discharge caused by the limited recovery rate of the existing natural gas purification sulfur recovery process, the utility model provides a sulfur-containing natural gas purification tail gas treatment device.

[0007] The sulfur-containing natural gas purification tail gas treatment device provided by the utility model comprises:

[0008] A first heater, the inlet end of which is connected to a tail gas source and has an air input pipeline connected upstream and / or downstream thereof, and the first heater is provided with a first heat exchange pipeline for heating by medium heat exchange;

[0009] A reactor, the inlet end of which is connected to the outlet end of the first heater, for input of mixed gas formed by tail gas and air; and

[0010] a sulfur condenser, an inlet end of which is connected with an outlet end of the reactor, for cooling the product outputted from the reactor to separate elemental sulfur, the sulfur condenser being provided with a second heat exchange pipeline for realizing condensation through medium heat exchange;

[0011] wherein an input end of the first heat exchange pipeline is connected with an output end of the second heat exchange pipeline, and an output end of the first heat exchange pipeline is connected with an input end of the second heat exchange pipeline.

[0012] In one embodiment, the high-temperature medium pipeline is a high-temperature steam pipeline, and the low-temperature medium pipeline is a low-temperature liquid pipeline.

[0013] In one embodiment, further comprising a mixer provided between the first heater and the reactor, an outlet end of the first heater and the air input pipeline downstream of the first heater are both connected with the mixer, and an outlet end of the mixer is connected with an inlet end of the reactor.

[0014] In one embodiment, further comprising a second heater provided on the air input pipeline downstream of the first heater, the second heater being provided with a third heat exchange pipeline for realizing heating through medium heat exchange, an input end and an output end of the third heat exchange pipeline being connected with the high-temperature medium pipeline and the low-temperature medium pipeline respectively.

[0015] In one embodiment, the first heat exchange pipeline, the second heat exchange pipeline and the third heat exchange pipeline all comprise an input pipe section and an output pipe section, and control valves are respectively provided on the input pipe section and the output pipe section.

[0016] In one embodiment, outlet ends of the first heater and the second heater and the inside of the reactor are all provided with temperature detectors.

[0017] In one embodiment, the sulfur condenser is configured with a first outlet for outputting elemental sulfur and a second outlet for outputting other products, and an oxygen content detector is provided at the second outlet.

[0018] In one embodiment, the first outlet is connected with a sulfur seal, and the second outlet is connected with a sulfur trap.

[0019] In one embodiment, the sulfur condenser is provided with a liquid level meter and a pressure gauge.

[0020] In one embodiment, a flow meter is provided on the air input pipeline; or the air input pipeline upstream and downstream of the first heater is connected in parallel with an air input main pipeline, and a flow meter is provided on the air input main pipeline.

[0021] The above technical features can be combined in various suitable manners or replaced by equivalent technical features, as long as the purpose of the present application can be achieved.

[0022] Compared with the prior art, the sulfur-containing natural gas purification tail gas treatment device has at least the following beneficial effects:

[0023] The sulfur-containing natural gas purification tail gas treatment device can mix the tail gas with air to perform a catalytic reaction, so that the residual H2S in the tail gas can be converted into elemental sulfur, and the heat required in the entire treatment process can be recycled, which not only realizes further recovery of sulfur in the tail gas, but also is energy-efficient BRIEF DESCRIPTION OF DRAWINGS

[0024] In the following, the present application will be described in more detail based on embodiments and with reference to the drawings. In which:

[0025] Figure 1 shows a schematic view of a first embodiment of the tail gas treatment device of the present application;

[0026] Figure 2 shows a schematic view of a second embodiment of the tail gas treatment device of the present application;

[0027] Figure 3 shows a schematic view of a third embodiment of the tail gas treatment device of the present application.

[0028] In the drawings, identical parts are provided with the same reference signs. The drawings are not true to scale.

[0029] REFERENCE SIGNS

[0030] 1 - tail gas source, 2 - tail gas input pipe, 3 - flow meter, 4 - first air valve, 5 - first air input pipe, 6 - first heater, 7 - second control valve, 8 - first output pipe section, 9 - first control valve; 10 - first input pipe section;

[0031] 11 - first temperature detector, 12 - mixer, 13 - second air input pipe, 14 - third temperature detector, 15 - mixed output pipe, 16 - reactor, 17 - reaction output pipe, 18 - sulfur condenser, 19 - second input pipe section, 20 - third control valve;

[0032] 21 - sulfur seal, 22 - liquid level meter, 23 - fourth control valve, 24 - second output pipe section, 25 - pressure gauge, 26 - oxygen content detector, 27 - second outlet, 28 - sulfur trap, 29 - first outlet, 30 - second air valve;

[0033] 31 - first heating output pipe, 32 - second heating output pipe, 33 - second heater, 34 - sixth control valve, 35 - third output pipe section, 36 - fifth control valve, 37 - third input pipe section, 38 - second temperature detector. DETAILED DESCRIPTION

[0034] The utility model will be further described below with reference to the drawings.

[0035] The embodiment of the utility model provides a kind of sulfur-containing natural gas purification tail gas treatment device, including first heater 6, reactor 16 and sulfur condenser 18.The inlet end of first heater 6 is connected with tail gas source 1 and its upstream and / or downstream is connected with air input pipeline, and first heater 6 is provided with the first heat exchange pipeline for heating by medium heat exchange;The inlet end of reactor 16 is connected with the outlet end of first heater 6, to supply the mixed gas formed by tail gas and air input;The inlet end of sulfur condenser 18 is connected with the outlet end of reactor 16, for cooling the product output by reactor 16 to separate out elemental sulfur, and sulfur condenser 18 is provided with the second heat exchange pipeline for condensing by medium heat exchange.

[0036] Wherein, the input end of first heat exchange pipeline is connected with the output end of second heat exchange pipeline high-temperature medium pipeline, and the output end of first heat exchange pipeline is connected with the input end of second heat exchange pipeline low-temperature medium pipeline.

[0037] Specifically, the tail gas treatment device provided by the utility model is mainly aimed at the technical problems mentioned in the background art, for the tail gas after sulfur-containing natural gas purification treatment, the sulfur recovery process (such as the Claus process recorded in the background art) currently adopted for sulfur-containing natural gas purification has a relatively obvious upper limit for recovery rate, so the tail gas generated after purification actually needs further tail gas treatment.

[0038] As shown in the drawings Figure 1 The tail gas treatment device of the utility model mainly includes first heater 6, reactor 16 and sulfur condenser 18, wherein first heater 6 and sulfur condenser 18 are both constructed as heat exchange type structure, that is, first heat exchange pipeline and second heat exchange pipeline are respectively constructed, and first heater 6 and sulfur condenser 18 are respectively in the flow path of first heat exchange pipeline and second heat exchange pipeline, so as to realize corresponding heating and condensing function by heat exchange mode.

[0039] The first heater 6 is connected with the tail gas source 1, in the embodiment, the tail gas source 1 can be a sulfur separator at the end of the Claus process, and the sulfur separator discharges the tail gas to the first heater 6 after separating sulfur. The air input pipe is connected upstream and / or downstream of the first heater 6, and is used to input air to cooperate with the tail gas to separate sulfur from the tail gas; according to the need. The air input pipe can be connected upstream of the first heater 6, so that the air can enter the first heater 6; the air input pipe can be connected downstream of the first heater 6, so that the air does not pass through the first heater 6. The reactor 16 is arranged downstream of the first heater 6, and if the air input pipe is connected downstream of the first heater 6, the reactor 16 is further arranged downstream of the air input pipe connection point. The reactor 16 is used to accept the mixed gas of air and tail gas to react under the corresponding catalysis to convert the sulfur in H2S in the tail gas into elemental sulfur. The reaction product (including elemental sulfur and other substances) of the reactor 16 enters the sulfur condenser 18, and under the condensation, the elemental sulfur is separated from the reaction product.

[0040] In the embodiment, as shown in Figure Figure 1 The first air input pipe 5 is connected only upstream of the first heater 6, and the corresponding tail gas treatment process is as follows: the tail gas of the tail gas source 1 enters the first heater 6 through the tail gas input pipe 2, the first air input pipe is connected to the tail gas input pipe 2, and the air enters the first heater 6 together with the tail gas; optionally, the air input pipe is provided with a flow meter 3 and a first air valve 4 for controlling the air flow. The first heat exchange pipe transfers high-temperature medium to the first heater 6, and heats the air and tail gas in the first heater 6 through heat exchange. The air and tail gas are heated and mixed in the first heater 6, and then output to the reactor 16 through the first heating output pipe 31. The mixed gas of air and tail gas is catalytically reacted in the reactor 16 to convert the sulfur in the H2S gas in the tail gas into elemental sulfur. The reaction product containing elemental sulfur enters the sulfur condenser 18 from the reactor 16 through the reaction output pipe 17. The second heat exchange pipe transfers low-temperature medium to the sulfur condenser 18, and cools the reaction product in the sulfur condenser 18 through heat exchange, so that the elemental sulfur is condensed and separated from the reaction product. The first heat exchange pipe and the second heat exchange pipe are connected to the high-temperature medium pipe and the low-temperature medium pipe, and for the medium, it is a heat release process in the first heat exchange pipe and a heat absorption process in the second heat exchange pipe, and then the heat exchange medium can circulate in the first heat exchange pipe and the second heat exchange pipe through the high-temperature medium pipe and the low-temperature medium pipe, to realize the recycling of heat.

[0041] The tail gas treatment device can mix the tail gas with air to perform catalytic reaction, so that the residual H2S in the tail gas can be converted into elemental sulfur, and the heat required in the whole treatment process can be recycled, which not only realizes the further recovery of sulfur in the tail gas, but also can be efficient and energy-saving.

[0042] Preferably, the high-temperature medium pipeline is a high-temperature steam pipeline, which can be a high-temperature water vapor pipeline; and the low-temperature medium pipeline is a low-temperature liquid pipeline, which can be a low-temperature water pipeline.

[0043] Preferably, the sulfur condenser 18 is provided with a liquid level meter 22 and a pressure gauge 25 for monitoring the liquid level and pressure of the sulfur condenser 18.

[0044] In one embodiment, the tail gas treatment device further comprises a mixer 12, which is arranged between the first heater 6 and the reactor 16, and the outlet end of the first heater 6 and the air input pipeline downstream of the first heater 6 are connected to the mixer 12, and the outlet end of the mixer 12 is connected to the inlet end of the reactor 16.

[0045] Specifically, as shown in the accompanying drawings, Figure 2 In this embodiment, only the second air input pipeline 13 is arranged downstream of the first heater 6; and optionally, the second air input pipeline 13 is provided with a flow meter 3 and a second air valve 30. The difference from the foregoing embodiment is that, in this embodiment, the air input through the second air input pipeline 13 does not pass through the first heater 6, but enters the mixer 12 together with the heated tail gas, is mixed in the mixer 12, is heated when mixed with the tail gas, and then the mixer 12 enters the reactor 16 through the mixing output pipeline 15. The purpose of this design is to realize the mixing of air and tail gas through the mixer 12, which can improve the mixing effect.

[0046] In one embodiment, the tail gas treatment device further comprises a second heater 33, which is arranged on the air input pipeline downstream of the first heater 6, and the second heater 33 is provided with a third heat exchange pipeline for heating through medium heat exchange, and the input end and the output end of the third heat exchange pipeline are connected to the high-temperature medium pipeline and the low-temperature medium pipeline, respectively.

[0047] Specifically, as shown in the accompanying drawings, Figure 3As shown, in the embodiment, a first air input pipe and a second air input pipe are arranged upstream and downstream of the first heater 6 respectively, a first air valve 4 and a second air valve 30 are arranged on the two air input pipes respectively, the second air input pipe is connected with the second heater 33, the second heater 33 is connected with the mixer 12 through a second heating output pipe 32, and the second heater 33 is also configured as a heat exchange type structure and heats through medium heat exchange of a third heat exchange pipe. Meanwhile, the input ends of the first air input pipe and the second air input pipe are connected in parallel to an air input main pipe, and a flow meter 3 is arranged on the air input main pipe. Based on the structure of the embodiment, part of the air can enter the tail gas input pipe 2, mix with the tail gas, and then be heated in the first heater 6, and the other part of the air can be heated in the second heater 33 and then enter the mixer 12 to further mix with the premixed mixed gas, so that the mixing effect and the heating effect can be considered. Of course, the first air valve 4 and the second air valve 30 can be controlled to open and close, so that all the air can enter the tail gas input pipe 2 or all the air can directly enter the second heater 33.

[0048] Preferably, as shown in the drawings Figure 3 As shown, the outlet ends of the first heater 6 and the second heater 33 and the inside of the reactor 16 are all provided with temperature detectors, i.e. a first temperature detector 11, a second temperature detector 38 and a third temperature detector 14, which are mainly used for detecting the heating temperature and the reaction temperature, so as to provide a basis for temperature control and ensure that the temperature meets the reaction requirements.

[0049] In one embodiment, the first heat exchange pipe, the second heat exchange pipe and the third heat exchange pipe each include an input pipe section and an output pipe section, and control valves are arranged on the input pipe section and the output pipe section respectively.

[0050] Specifically, as shown in the drawings Figures 1 to 3 As shown, the first heat exchange pipe includes a first input pipe section 10 and a first output pipe section 8, and a first control valve 9 and a second control valve 7 are arranged on the two pipe sections respectively. The second heat exchange pipe includes a second input pipe section 19 and a second output pipe section 24, and a third control valve 20 and a fourth control valve 23 are arranged on the two pipe sections respectively. The third heat exchange pipe includes a third input pipe section 37 and a third output pipe section 35, and a fifth control valve 36 and a sixth control valve 34 are arranged on the two pipe sections respectively. Among them, the first input pipe section 10 and the third input pipe section 37 are used for inputting high-temperature steam, and the first output pipe section 8 and the third output pipe section 35 are used for outputting low-temperature liquid; and the second input pipe section 19 is used for inputting low-temperature liquid, and the second output pipe section 24 is used for outputting high-temperature steam.

[0051] In one embodiment, the sulfur condenser 18 is configured with a first outlet 29 for outputting elemental sulfur and a second outlet 27 for outputting other products, the second outlet 27 is provided with an oxygen content detector 26, the first outlet 29 is connected with a sulfur seal 21, and the second outlet 27 is connected with a sulfur trap 28.

[0052] Specifically, as shown in the drawings Figures 1 to 3 The sulfur seal 21 is used to collect elemental sulfur, and the sulfur trap 28 is used to trap residual elemental sulfur in the reaction products, which can be trapped in the form of filtration. At the same time, the second outlet 27 is provided with an oxygen content detector 26, which can reflect the oxygen content in the processing process and guide the adjustment of the flow of air to ensure the conversion effect of the reaction.

[0053] In the description of the present application, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "back", "inner", "outer", "left", "right" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0054] Although the present application is described herein with reference to particular embodiments, it should be understood that these examples are merely illustrative of the principles and applications of the present application. It should therefore be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed, without departing from the spirit and scope of the present application as defined in the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways other than those described by the original claims. It should also be understood that features described in connection with individual embodiments can be used in other described embodiments.

Claims

1. A sulfur-containing natural gas purification tail gas treatment apparatus characterized by comprising: The application relates to a sulfur condenser and a sulfur condensing method. The application comprises: a first heater, the inlet end of which is connected to a tail gas source, and the upstream and / or downstream of which is connected to an air input pipeline, the first heater being provided with a first heat exchange pipeline for heat exchange by a medium to realize heating; a reactor, the inlet end of which is connected to the outlet end of the first heater to input a mixed gas formed by tail gas and air; and a sulfur condenser, the inlet end of which is connected to the outlet end of the reactor to cool the product output by the reactor to separate elemental sulfur, the sulfur condenser being provided with a second heat exchange pipeline for heat exchange by a medium to realize condensing; 2. The sulfur-containing natural gas purification tail gas treatment apparatus according to claim 1, characterized by, wherein the input end of the first heat exchange pipeline is connected to a high-temperature medium pipeline, and the output end of the first heat exchange pipeline is connected to a low-temperature medium pipeline.

3. The sulfur-containing natural gas purge tail gas treatment apparatus according to claim 1, characterized by, The high-temperature medium pipeline is a high-temperature steam pipeline, and the low-temperature medium pipeline is a low-temperature liquid pipeline. The application further comprises:

4. The sulfur-containing natural gas purification tail gas treatment apparatus according to claim 1, characterized by a mixer arranged between the first heater and the reactor, the outlet end of the first heater and the air input pipeline downstream of the first heater being connected to the mixer, and the outlet end of the mixer being connected to the inlet end of the reactor. The application further comprises:

5. The sulfur-containing natural gas purge tail gas treatment apparatus as claimed in claim 4, characterized by a second heater arranged on the air input pipeline downstream of the first heater, the second heater being provided with a third heat exchange pipeline for heat exchange by a medium to realize heating, the input end and the output end of the third heat exchange pipeline being connected to the high-temperature medium pipeline and the low-temperature medium pipeline respectively.

6. The sulfur-containing natural gas purification tail gas treatment apparatus according to claim 4, characterized by The first heat exchange pipeline, the second heat exchange pipeline and the third heat exchange pipeline each comprise an input pipe section and an output pipe section, and control valves are arranged on the input pipe section and the output pipe section respectively.

7. The sulfur-containing natural gas purification tail gas treatment apparatus according to claim 1, characterized by Temperature detectors are arranged at the outlet ends of the first heater and the second heater and in the interior of the reactor.

8. The sulfur-containing natural gas purification tail gas treatment apparatus according to claim 7, characterized by The sulfur condenser is configured with a first outlet for outputting elemental sulfur and a second outlet for outputting other products, and an oxygen content detector is arranged at the second outlet.

9. The sulfur-containing natural gas purge tail gas treatment apparatus according to claim 1 or 7, characterized by, The first outlet is connected to a sulfur seal, and the second outlet is connected to a sulfur trap.

10. The sulfur-containing natural gas purification tail gas treatment apparatus according to claim 1, characterized by, The sulfur condenser is provided with a liquid level meter and a pressure gauge. A flow meter is arranged on the air input pipeline upstream and downstream of the first heater; or The air input pipelines upstream and downstream of the first heater are connected in parallel to an air input main pipeline, and a flow meter is arranged on the air input main pipeline.

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