TWI464121B - Ammonia-containing fluid processing method and device thereof - Google Patents

Description

Ammonia-containing fluid treatment method and device thereof

The present invention relates to a fluid processing method and apparatus therefor, and more particularly to an ammonia containing fluid processing method and apparatus therefor.

In the petrochemical, semiconductor, and optoelectronic industries, many processes often use ammonia (NH ₃ ) for reactions, such as those used in etching, epitaxy, or cleaning, and doping at the back end of the process. In the middle, the exhaust gas cannot be directly discharged due to the ammonia content, so it is necessary to set up an exhaust gas treatment device to generate ammonia-containing wastewater by water absorption. After that, the ammonia-containing wastewater is treated, and after the ammonia is absorbed or decomposed, the wastewater is discharged in accordance with the discharge standard.

At present, among the above methods for treating ammonia-containing wastewater, the most widely used method is a sulfuric acid solution as an absorbent, which is added to ammonia-containing wastewater through sulfuric acid to absorb ammonia in the wastewater and react with it to produce ammonium sulfate. (NH ₄ ) ₂ SO ₄ ) reduces the ammonia content in the fluid. Thereafter, the ammonium sulfate is recycled.

However, the above treatment method additionally forms by-products (ammonium sulfate), which still needs to be separated from the wastewater. The source of this ammonium monosulfate is obtained from the treatment process of industrial wastewater or tail gas, so there is considerable doubt about whether it will cause harm to the human body in use, and it cannot be utilized, for example, as a nitrogen fertilizer, so ammonium sulfate itself will also be used. Causes problems in the subsequent disposal of hazardous waste and leads to an increase in the cost of industrial wastewater or tail gas treatment.

In addition, even if the ammonia in the wastewater is absorbed by the sulfuric acid solution, the ammonium sulfate is recovered, before Traces of ammonia remain in the wastewater, making this wastewater still not directly discharged.

In addition, some factories have a small amount of ammonia-containing tail gas emissions. If an exhaust gas treatment device is installed to absorb ammonia gas as water, the cost is too high for these plants.

Moreover, the tail gas treated by the exhaust gas treatment device still has a small amount of ammonia remaining, and the discharge standard cannot be met. Therefore, the foregoing exhaust gas still needs to pass into a reaction tank containing nitrous acid, and the ammonia is sufficiently reacted with nitrous acid to be decomposed into nitrogen and water, and the final exhaust gas can meet the discharge standard.

However, the high cost of nitrous acid makes the treatment cost of ammonia-containing tail gas or wastewater always high.

In view of the above problems, the present invention provides an ammonia-containing fluid treatment method and apparatus therefor, which solves the problem in the prior art that high-cost chemicals must be used to treat ammonia gas.

The invention discloses a method for treating an ammonia-containing fluid, comprising the steps of: providing a reaction tank with nitrous oxide chlorine; conveying an ammonia-containing fluid into the reaction tank; and irradiating the nitrous oxide chlorine in the reaction tank with a light source to form chlorine. Free radicals and nitric oxide; ammonia in the ammonia-containing fluid reacts with chlorine radicals to form ammonia and hydrogen chloride, and reacts ammonia with nitrogen monoxide to form nitrogen and water.

The invention also discloses an ammonia-containing fluid treatment device comprising a reaction tank and a light source. The reaction tank has an inlet and an outlet, and a solution is stored in the reaction tank, and the solution contains nitrous oxide chlorine. The light source is disposed in the reaction tank to illuminate a light toward the solution. Wherein, nitrous oxide chloride receives light and decomposes to form chlorine radicals and nitric oxide, and the ammonia-containing fluid enters the reaction tank from the inlet, and is contained in the ammonia-containing fluid. Ammonia reacts with chlorine radicals and nitric oxide to form nitrogen and water, and exits the reaction tank from the outlet.

The aforementioned ammonia-containing fluid may be an exhaust gas containing ammonia or a wastewater containing ammonia.

The aforementioned nitrosonium chloride is formed by the reaction of nitric acid and hydrochloric acid.

The effect of the invention is that the nitrous oxide chloride forms a chlorine radical and nitric oxide by irradiating a solution containing nitrous oxide chlorine in a reaction tank, so that ammonia in the ammonia-containing fluid can be combined with chlorine radicals. The action of nitrogen oxides, which in turn forms nitrogen and water, not only reduces the ammonia content in the treated ammonia-containing fluid, but also allows the treated ammonia-containing fluid to be directly discharged to the external environment. Nitrous citrate can be formed by mixing nitric acid and hydrochloric acid, and the main function of hydrochloric acid is catalyst. The main chemical consumed during the treatment is nitric acid. Compared to conventional chemicals for treating ammonia, the cost of nitric acid is relatively low, thereby saving subsequent processing costs.

The features, implementations, and utilities of the present invention are described in detail below with reference to the drawings.

The ammonia-containing fluid treatment method and device disclosed in the invention are suitable for the deamination process of ammonia-containing tail gas or ammonia-containing wastewater generated at the back end of the industrial process.

As shown in FIG. 1 and FIG. 2, the ammonia-containing fluid treatment method and apparatus disclosed in the first embodiment of the present invention can directly treat the ammonia-containing tail gas or waste water generated at the rear end of the industrial process, or be attached to the exhaust gas. After the treatment device, the ammonia-containing wastewater discharged from the tail gas treatment device is further processed.

The ammonia-containing fluid processing apparatus 100 includes a reaction tank 110 and a light source 120 disposed in the reaction tank 110. The light source 120 may be, but not limited to, ultraviolet light.

The inside of the reaction tank 110 has an acidic environment, for example, a dilute sulfuric acid solution (PH<<7) and a relatively high hydrogen ion (H ⁺ ). Nitric acid (HNO ₃ ) and hydrochloric acid (HCl) are supplied in the reaction tank 110 in advance, and nitric acid and hydrochloric acid are reacted in the reaction tank 110 to form nitrosyl chloride (NOCl), so that the reaction tank 110 easily forms a sub-containing A solution of nitronium chloride.

The reaction formula of the above nitric acid and hydrochloric acid is: HNO ₃ + 3HCl → NOCl + Cl ₂ + 2H ₂ O.

The acid-biased environment can bias the chemical equilibrium of the above reaction formula to the right side of the reaction formula.

In the treatment of the ammonia-containing fluid, mainly, a reaction tank 110 having nitrous oxide chlorine (S101) is supplied, and the ammonia-containing fluid is supplied into the reaction tank 110 through the inlet 111 of the reaction tank 110 (S102).

The light source (S103) disposed in the reaction tank 110 is turned on, and the light source is irradiated with light to the nitrous oxide-containing chlorine solution, so that the nitrous oxide chlorine undergoes photodissociation after receiving light, and decomposes to form chlorine radicals and a Nitric oxide (S104), this photolysis has a relatively good effect when irradiated with ultraviolet light, but does not exclude irradiation with other light.

The reaction formula of the above photodecomposition is: NOCl + hv → NO +. Cl

Next, the formed chlorine radical (chlorine atom) reacts with ammonia in the ammonia-containing fluid to form ammonia gas (NH ₂ ) and hydrogen chloride (HCl) (S105). Its reaction formula is: NH ₃ +. Cl→NH ₂ +HCl.

Ammonia reacts with nitric oxide to form an intermediate product, nitrosamide (H ₂ NNO), and then forms nitrogen and water (S106). The reaction formula is: NH ₂ +NO→[H ₂ NNO]→H ₂ O+N ₂ .

Therefore, after the end of the entire treatment process, the ammonia in the ammonia-containing fluid will eventually be converted into nitrogen and water, thus not only effectively reducing the ammonia concentration in the ammonia-containing fluid, but also producing products: nitrogen and water. It is directly discharged from the outlet 112 of the reaction tank 110 to the external environment.

Further, in the above treatment, after the chlorine radical reacts with ammonia in the ammonia-containing fluid to form ammonia (NH ₂ ) and hydrogen chloride (HCl). Therefore, in the reaction tank, hydrogen chloride acts as a catalyst and is not consumed by the reaction of decomposing ammonia. Therefore, nitric acid is added to the reaction tank to maintain the supply of nitrous oxide chlorine. The cost of nitric acid is relatively low compared to conventional chemicals that treat ammonia.

The ammonia-containing fluid processing method and device of the present invention can be directly disposed at the tail end of the industrial process to directly receive and process the ammonia-containing wastewater or tail gas generated in the industrial process, and can be added to the conventional deamination reaction with sulfuric acid. After the treatment, the concentration of ammonia is further reduced to a standard that can be discharged.

As shown in FIG. 3 and FIG. 4, the second embodiment of the present invention is substantially the same as the first embodiment, and the difference between the two is that the ammonia-containing fluid processing apparatus 100 disclosed in the second embodiment of the present invention. An additional waste liquid tank 200 of another apparatus may be coupled to receive and process the ammonium sulfate-containing fluid in the waste liquid tank 200.

Moreover, in the treatment method, the ammonium sulfate-containing fluid (S201) is mainly provided first, and the ammonium sulfate is decomposed by heating or other means, and the reaction formula is: (NH ₄ ) ₂ SO ₄ → 2NH ₃ + 2H ₂ O + SO ₂ To form an ammonia-containing fluid (S202).

Then, the ammonia-containing fluid is again transported into the reaction tank 110 of the ammonia-containing fluid processing apparatus 100 (S203), and the light source 120 is turned on (S204) to cause nitrous oxide chlorine in the reaction tank 110. The photodecomposition generates chlorine radicals and nitric oxide (S205). Next, ammonia in the ammonia-containing fluid is reacted with chlorine radicals to generate ammonia gas (S206), and ammonia gas is reacted with nitrogen monoxide to generate nitrogen gas and water (S207).

Therefore, the ammonia-containing fluid treatment method and apparatus thereof of the present invention can be further applied to a conventional deamination treatment procedure in addition to the deamination treatment of an ammonia-containing fluid, thereby decomposing the sulfuric acid produced during the treatment. Ammonium to reduce the generation of unwanted by-products, and to allow the treated fluid to be directly discharged to the external environment in compliance with emission standards.

The above-mentioned ammonia-containing fluid treatment method and apparatus of the present invention are photodegraded by nitrous oxide chlorine in a reaction tank to obtain chlorine radicals and nitric oxide, and then by chlorine radicals and ammonia-containing fluids. The ammonia reaction produces ammonia gas and the gas reacts with nitric oxide to form nitrogen and water. Nitrous oxide is obtained by reacting nitric acid with hydrochloric acid, and mainly consumes nitric acid in the process, and hydrochloric acid acts only as a catalyst.

The chlorine radicals and nitric oxide obtained by nitrous oxide can decompose ammonia in the ammonia-containing fluid, so that the treated ammonia-containing fluid meets emission standards and no longer produces by-products that cannot be discharged. Therefore, the treatment efficiency of the ammonia-containing fluid is effectively improved and the treatment cost is saved. In addition, the ammonia-containing fluid treatment method and apparatus thereof of the present invention can directly treat the ammonia-containing tail gas or waste water generated by the back end of the industrial process (if the amount of emissions is small), or be added to the exhaust gas treatment device, and further treat the tail gas treatment. The ammonia-containing wastewater discharged from the device is therefore of considerable practical value.

Although the embodiments of the present invention are disclosed above, it is not intended to limit the present invention, and those skilled in the art, regardless of the spirit and scope of the present invention, the shapes, structures, and features described in the scope of the present application. And the amount can be done a little The scope of patent protection of the present invention is defined by the scope of the patent application attached to the specification.

100‧‧‧Ammonia-containing fluid treatment unit

110‧‧‧Reaction tank

111‧‧‧ Entrance

112‧‧‧Export

120‧‧‧Light source

200‧‧‧ Waste tank

Fig. 1 is a flow chart showing a method of treating an ammonia-containing fluid according to a first embodiment of the present invention.

Fig. 2 is a plan view showing the ammonia-containing fluid processing apparatus of the first embodiment of the present invention.

Figure 3 is a plan view showing an ammonia-containing fluid processing apparatus according to a second embodiment of the present invention.

Figure 4 is a flow chart showing a method of treating an ammonia-containing fluid according to a second embodiment of the present invention.

100‧‧‧Ammonia-containing fluid treatment unit

110‧‧‧Reaction tank

111‧‧‧ Entrance

112‧‧‧Export

120‧‧‧Light source

Claims (10)

An ammonia-containing fluid treatment method comprising the steps of: providing a reaction tank having nitrous oxide chlorine; conveying an ammonia-containing fluid into the reaction tank; opening a light source in the reaction tank; and irradiating the reaction tank by the light source The nitrous oxide chlorine forms a chlorine radical and nitric oxide; the ammonia in the ammonia-containing fluid reacts with the chlorine radical to form ammonia gas and hydrogen chloride; and the ammonia gas reacts with the nitric oxide to form nitrogen gas and water. The method for treating an ammonia-containing fluid according to claim 1, wherein the step of decomposing the nitrous oxide chlorine in the reaction tank by the light source is irradiating the nitrosyl chloride with ultraviolet light. The ammonia-containing fluid treatment method according to claim 1, further comprising the steps of: supplying nitric acid into the reaction tank; and supplying hydrochloric acid into the reaction tank, and reacting with the nitric acid to form the nitrous oxide chlorine. The method for treating an ammonia-containing fluid according to claim 3, wherein the reacting the ammonia with the chlorine radical to form the ammonia gas and the hydrogen chloride further comprises: reacting the hydrogen chloride with the nitric acid to form another nitrous oxide chlorine. The method of treating an ammonia-containing fluid according to claim 1, wherein the reaction vessel is maintained in an acidic environment. The method for treating an ammonia-containing fluid according to claim 1, further comprising the steps of: providing a fluid containing ammonium sulfate; The ammonium sulfate is decomposed by heating to form an ammonia-containing fluid. The method of treating an ammonia-containing fluid according to claim 1, wherein the ammonia-containing fluid is ammonia-containing wastewater or tail gas. An ammonia-containing fluid processing apparatus comprising: a reaction tank having an inlet and an outlet, a solution stored in the reaction tank, and nitrous oxide chlorine formed in the solution; and a light source disposed in the reaction tank And irradiating a light to the solution; wherein the nitrous oxide chlorine receives the light, and decomposes to form a chlorine radical and nitrogen monoxide, the ammonia-containing fluid enters the reaction tank from the inlet, and the ammonia in the ammonia-containing fluid Nitrogen and water are formed by the action of the chlorine radical and the nitric oxide, and are discharged from the outlet outside the reaction vessel. The ammonia-containing fluid processing apparatus of claim 8, wherein the light source is ultraviolet light. The ammonia-containing fluid processing apparatus according to claim 8, wherein the nitrous oxide chlorine is formed by reacting nitric acid and hydrochloric acid.