Desulfurization system for acidic tail gas

Abstract

The utility model discloses an acidic tail gas desulfurization system, which solves the problems of high operation cost, environmental pollution and the like in the prior art and comprises a heat exchange device, a primary desulfurization tower, a secondary desulfurization tower and an induced draft fan, a boiler combustion fan is arranged at an inlet of the heat exchange device, a first outlet of the heat exchange device is communicated with an inlet of the primary desulfurization tower, and a second outlet of the heat exchange device is communicated with an outlet of the secondary desulfurization tower. A first outlet of the first-stage desulfurization tower is communicated with a first inlet of the second-stage desulfurization tower, and treated tail gas is discharged through an induced draft fan; a second outlet of the primary desulfurization tower is communicated with a neutralizing tank, an outlet of the neutralizing tank is communicated with an inlet of an oxidizer, an outlet of the oxidizer is communicated with an inlet of an evaporator, and an outlet of the evaporator is communicated with a second inlet of the secondary desulfurization tower. According to the utility model, the removal efficiency of SO2 in the tail gas is effectively improved, the sulfur content in the discharged tail gas is ensured to be far lower than the environmental protection standard, and the environmental pollution is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to sulfur-containing tail gas treatment technical field especially relates to a kind of desulfurization system of acidic tail gas. BACKGROUND

[0002] In natural gas purification treatment process, MDEA solution (methyl diethanolamine solution, also known as "amine solution") is widely used to remove CO2 and sulfide in natural gas. The amine solution after absorption is regenerated by low pressure and high temperature, and in this process, hydrogen sulfide, SO2 and other sulfides are released together with CO2. Since these released tail gas contains sulfides, according to relevant environmental protection standards, the sulfur-containing waste gas needs to be strictly controlled in concentration when discharged on site. However, the commonly used tail gas treatment process, such as using complex iron, iron sulfide, activated carbon and other substances to remove sulfides in tail gas, generally has the disadvantages of high operating cost, high energy consumption and environmental pollution. Therefore, it is particularly important to develop a treatment process that can effectively reduce the sulfur content in tail gas and realize low-energy consumption recovery and utilization of sulfides. SUMMARY

[0003] The utility model provides a kind of desulfurization system of acidic tail gas to solve the technical problems of high operating cost, environmental pollution and other disadvantages of prior art.

[0004] To achieve the above purpose, the utility model provides the following technical scheme:

[0005] The desulfurization system of acidic tail gas provided by the application comprises a heat exchange device, a primary desulfurization tower, a secondary desulfurization tower, and a draft fan. A boiler combustion-supporting fan is arranged at the inlet of the heat exchange device. The first outlet of the heat exchange device is in communication with the inlet of the primary desulfurization tower. The first outlet of the primary desulfurization tower is in communication with the first inlet of the secondary desulfurization tower. The treated tail gas is discharged by the draft fan. The second outlet of the primary desulfurization tower is in communication with a neutralization tank. The outlet of the neutralization tank is in communication with the inlet of an oxidizer. The outlet of the oxidizer is in communication with the inlet of an evaporator. The outlet of the evaporator is in communication with the second inlet of the secondary desulfurization tower.

[0006] Further, the primary desulfurization tower is connected with a primary circulating pump, which circulates the absorption liquid in the primary desulfurization tower to absorb sulfur dioxide. The secondary desulfurization tower is connected with a secondary circulating pump, which circulates the absorption liquid in the secondary desulfurization tower to absorb sulfur dioxide.

[0007] Further, the second outlet of the heat exchange device is in communication with a gas-fired boiler. The outlet of the gas-fired boiler is in communication with the inlet of the heat exchange device. The flue gas is recycled by the gas-fired boiler.

[0008] Further, the secondary desulfurization tower is connected with the primary desulfurization tower through a pipeline, and the excess absorption liquid in the secondary desulfurization tower enters the primary desulfurization tower through the pipeline for utilization.

[0009] The utility model discloses the beneficial effect that realizes:

[0010] The desulfurization system of acid tail gas provided by the utility model, in the desulfurization process, the Na2SO3 and Na2SO4 solution formed are further treated, can be converted into sodium sulfate particles, realizes the sulfide resource recycling, reduces waste discharge, and creates economic benefits again;Through the introduction heat exchange device and gas boiler, realize the recycling of flue gas, improve the heat efficiency of system whole. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 The process flow chart of the utility model embodiment;

[0012] The drawings are only for example description, and can not be understood as the limitation of the patent;In order to better illustrate the embodiment, some components of the drawings can be omitted, enlarged or reduced, and do not represent the size of actual product;For those skilled in the art, it is understandable that some well-known structures and their description in the drawings can be omitted;Same or similar signs correspond to same or similar components;The use of language describing position relation in the drawings is only for example description, and can not be understood as the limitation of the patent. DETAILED DESCRIPTION

[0013] The technical scheme in the utility model embodiment will be described clearly and completely in combination with the drawings in the utility model embodiment, and obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model. In addition, the technical scheme of each embodiment can be combined with each other, but it must be based on that the ordinary skilled in the art can realize, when the combination of technical scheme appears contradictory or unachievable, it should be considered that the combination of technical scheme does not exist, also not in the protection scope required by the utility model.

[0014] The technical scheme of the utility model will be introduced and described in detail in combination with specific drawings.

[0015] As Figure 1As shown, a desulfurization system of an acid tail gas comprises a heat exchange device, a first-stage desulfurization tower, a second-stage desulfurization tower, and an induced draft fan. A boiler combustion-supporting fan is arranged at an inlet of the heat exchange device. A first outlet of the heat exchange device is in communication with an inlet of the first-stage desulfurization tower. A first outlet of the first-stage desulfurization tower is in communication with a first inlet of the second-stage desulfurization tower. The treated tail gas is discharged through the induced draft fan. A second outlet of the first-stage desulfurization tower is in communication with a neutralization tank. An outlet of the neutralization tank is in communication with an inlet of an oxidizer. An outlet of the oxidizer is in communication with an inlet of an evaporator. An outlet of the evaporator is in communication with a second inlet of the second-stage desulfurization tower. The first-stage desulfurization tower is connected with a first-stage circulating pump. The first-stage circulating pump is used to make the absorption liquid circulate in the first-stage desulfurization tower to absorb sulfur dioxide. The second-stage desulfurization tower is connected with a second-stage circulating pump. The second-stage circulating pump is used to make the absorption liquid circulate in the second-stage desulfurization tower to absorb sulfur dioxide. A second outlet of the heat exchange device is in communication with a gas-fired boiler. An outlet of the gas-fired boiler is in communication with an inlet of the heat exchange device. The gas-fired boiler is used to realize the recycling of the flue gas. The second-stage desulfurization tower is connected with the first-stage desulfurization tower through a pipeline. The excess absorption liquid in the second-stage desulfurization tower is introduced into the first-stage desulfurization tower through the pipeline.

[0016] The above-described desulfurization system of an acid tail gas is described in detail as follows.

[0017] (1) When the MDEA decarbonization liquid is regenerated, the sulfur-containing tail gas is released. The tail gas is first introduced into the gas-fired boiler. The high temperature in the furnace is used to oxidize all the sulfides in the tail gas into SO2.

[0018] (2) The induced draft fan is used to generate suction. The tail gas containing SO2 is introduced into the first-stage desulfurization tower and the second-stage desulfurization tower. NaOH solution is added into the first-stage desulfurization tower and the second-stage desulfurization tower. Under the action of the first-stage circulating pump and the second-stage circulating pump, SO2 is fully contacted with the NaOH solution. SO2 is absorbed to form Na2SO3. The tail gas is safely discharged after desulfurization.

[0019] (3) The saturated absorption liquid formed in the first-stage desulfurization tower is introduced into the neutralization tank. NaOH solution is added into the neutralization tank to neutralize the saturated absorption liquid.

[0020] (4) The neutralized solution is introduced into the oxidizer to be oxidized. The Na2SO3 is converted into Na2SO4.

[0021] (5) The formed Na2SO3 solution is subjected to superoxygen nanometer microbubble oxidation process to convert it into Na2SO4, the alkali liquor absorbs sulfide, at the same time, the concentration of Na2SO4 solution is continuously increased, at the same time, the alkali liquor is subjected to evaporation to continuously increase the concentration, and finally, condensation is formed to form crystallization, after drying and dehydration, the final product, sodium sulfate particles, is generated; specifically, the solution in the oxidizer is pumped into the evaporator, steam is continuously added into the evaporator, the alkali liquor absorbs sulfide, at the same time, the concentration of Na2SO4 solution is continuously increased, the alkali liquor is subjected to evaporation, three-effect evaporation gas is used to continuously increase the concentration of the material, and finally, condensation is formed to form crystallization, centrifugation is performed, after drying and dehydration, the final product, sodium sulfate particles, is generated;

[0022] (6) The condensate generated by the evaporator is introduced into the secondary desulfurization tower to cool the treated tail gas.

[0023] The above-mentioned sequence numbers of the embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments. The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A system for desulphurization of an acid tail gas, characterized in that, The application relates to a flue gas desulfurization device, which comprises a heat exchange device, a first-stage desulfurization tower, a second-stage desulfurization tower and an induced draft fan, a boiler combustion-supporting fan is arranged at the inlet of the heat exchange device, the first outlet of the heat exchange device is communicated with the inlet of the first-stage desulfurization tower, the first outlet of the first-stage desulfurization tower is communicated with the first inlet of the second-stage desulfurization tower, and the treated tail gas is discharged through the induced draft fan; the second outlet of the first-stage desulfurization tower is communicated with a neutralizing tank, the outlet of the neutralizing tank is communicated with the inlet of an oxidizer, the outlet of the oxidizer is communicated with the inlet of an evaporator, and the outlet of the evaporator is communicated with the second inlet of the second-stage desulfurization tower.

2. The system for desulphurization of an acid tail gas according to claim 1, characterized in that, The first-stage desulfurization tower is connected with a first-stage circulating pump, the absorption liquid is circulated in the first-stage desulfurization tower to absorb sulfur dioxide through the first-stage circulating pump; and the second-stage desulfurization tower is connected with a second-stage circulating pump, the absorption liquid is circulated in the second-stage desulfurization tower to absorb sulfur dioxide through the second-stage circulating pump.

3. The system for desulphurization of acid tail gas according to claim 1, wherein, The second outlet of the heat exchange device is communicated with a gas boiler, the outlet of the gas boiler is communicated with the inlet of the heat exchange device, and the flue gas is recycled through the gas boiler.

4. The system for desulphurization of acid tail gas according to claim 1, wherein, The second-stage desulfurization tower is connected with the first-stage desulfurization tower through a pipeline, and the excess absorption liquid in the second-stage desulfurization tower is introduced into the first-stage desulfurization tower through the pipeline for utilization.

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