CN102776034A

CN102776034A - Method for treating high-concentration ammonia and nitrogen in coking gas

Info

Publication number: CN102776034A
Application number: CN2012102533213A
Authority: CN
Inventors: 雷春生; 张凤娥; 包铠
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2012-07-18
Filing date: 2012-07-18
Publication date: 2012-11-14
Anticipated expiration: 2032-07-18
Also published as: CN102776034B

Abstract

The invention relates to a method for treating high-concentration ammonia and nitrogen in coking gas and belongs to the field of wastewater treatment. Coking gas containing ammonia and nitrogen is desulfurized and absorbed by orthophosphate before being introduced into an ammonia still, and N2 is generated and emitted to air under the catalytic action of organic denitrifying agent and heavy metal oxide. The catalyst mainly comprises, by mass percent, 20%-25% of bismuth oxide, 15%-20% of lutetium oxide, 10-15% of yttrium oxide, beta-Fe3O4 and the like. The organic denitrifying agent comprises, by mass percent, 40%-60% of polypropylene cyanide, 40%-60% of ethylene cyanide, and 10%-20% of CH3(SiOH)3. The method for treating ammonia and nitrogen waste gas has the advantages that resource consumption is low, recycling rate of absorbent is high, secondary pollution is avoided and the like. After the waste gas with the ammonia-nitrogen concentration of 3000-4000mg/L from a coking gas plant is treated by the method, the ammonia-nitrogen concentration decreases to lower than 12mg/L, and removal rate reaches more than 99.96%.

Description

A kind of method of handling coke gas middle and high concentration ammonia nitrogen

Technical field

The invention discloses a kind of method of handling coke gas middle and high concentration ammonia nitrogen, belong to the off gas treatment field.

Background technology

Coke gas is meant with several kinds of bituminous coal and is made into coking coal, in pit kiln, through in the output tar products, obtaining inflammable gas behind the high temperature carbonization, produces a large amount of ammonias but in concrete production process, understand.The people can occur shedding tears after sucking a large amount of ammonias in a short time, pharyngalgia, hoarseness, cough, sputum streaked with blood silk, uncomfortable in chest, expiratory dyspnea; Can be with dizzy, headache, feel sick, vomiting, weak etc.; Wet lung, adult respiratory distress syndrome can take place in severe patient, simultaneously the respiratory tract symptom possibly take place.If the ammonia that sucks is too much, cause ammonia excessive concentration in the blood, will cause through the reflex action of trigeminal nerve tip heart stop fight and breath stopped threat to life.Long-term contact ammonia, symptoms such as skin pigment deposition or finger ulcer may appear in groups of people.

The method of handling ammonia at present mainly contains: physics, chemistry and biological method.Physical method mainly is to utilize the direct absorption of N H of absorption unit ₃For example: publication number is 102179135A, and name is called " a kind of ammonia absorption unit " said a kind of absorption unit of being made up of gas-liquid separation snubber, condensate vacuum unit, cooling and absorbing tower, condensing surface and water reservoir earlier NH ₃Be condensed into liquid state, soluble in water again.This method can effectively be removed airborne ammonia, makes it reach discharging standards, but not processing of the high density ammoniacal liquor that obtains can cause secondary pollution to environment, and the power consumption of this kind method is very high, uneconomical.Chemical process mainly is to utilize acidic substance and NH ₃Reaction, absorption of N H ₃For example: publication number is 1778707; Name is called " a kind of high-concentration ammonia nitrogenous wastewater treatment technology " the said waste residue that contains nitrite anions or waste liquid that produces in the Chemical Manufacture that utilize; Join in the waste water that contains ammonia nitrogen, the method that drips the pH value of sulphuric acid soln conditioned reaction solution is again removed ammonia nitrogen.This method has produced a large amount of NH when removing ammonia nitrogen ₄ ⁺, can cause body eutrophication, cause secondary pollution.Biological method mainly is a nitrification of utilizing mikrobe, removes ammonia.For example publication number is 101525179, and the effect that name is called the anaerobic ammonia oxidizing bacteria that " a kind of method of anaerobic ammonia oxidation treatment of low-concentration ammonia nitrogen wastewater " said utilization domestication obtains removes the ammonia nitrogen in anhydrating.This method power consumption is high, and needs the environment of alkalescence, and is impracticable.

Summary of the invention

The present invention is high around prior art power consumption in handling the process of ammonia, needs alkaline environment and in treating processes, can produce secondary pollution problems, provide a kind of can be NH ₃Be converted into N ₂Method, this method is simply effective, has realized under lower cost, carrying out catalyzed conversion, making this method use in practice becomes possibility.

In order to achieve the above object, the technical scheme of the present invention's employing is following:

(1) coke gas generates DAP and primary ammonium phosphate mixing solutions through in the absorption tower, absorbing with ortho-phosphoric acid after the desulfurization;

(2) constantly circulate mixed solution with lift pump then, absorb ammonia repeatedly, until generating Secondary ammonium phosphate fully;

(3) be passed into the DAP that generates in the ammonia still with pipeline, add the organic denitrifier of 10～30ppm;

(4) Bi-Lu-Y-Re-Ir-Sr/ β-Fe is installed in the ammonia still ₃O ₄Catalyzer;

(5) in ammonia still, feed steam, Secondary ammonium phosphate resolves into primary ammonium phosphate and ammonia;

(6) ammonia is reduced into nitrogen under the effect of catalyzer, and Secondary ammonium phosphate is squeezed into the absorption cat head with recycle pump, reuptakes the ammonia in the piped gas.

Said organic denitrifier is by Vestolen PP 7052 cyanogen, ethene cyanogen, CH ₃(SiOH) ₃Form, its mass percent is Vestolen PP 7052 cyanogen 40%～60%, ethene cyanogen 40%～60%, CH ₃(SiOH) ₃10%～20%.

Heavy metal content is respectively bismuth oxide 20%～25%, lutecium oxide 15%～20%, yttrium oxide 10%～15% in oxide mass per-cent in the said catalyzer, rhenium oxide 20%～25%, iridium oxide 15%～20%, strontium oxide 13%～20%.

Compared with prior art, the significant advantage that has of the present invention:

(1) with phosphoric acid is absorption agent; Be utilized under the different pH conditions, phosphoric acid hydrogen radical ion and dihydrogen phosphate ions can transform mutually, thereby discharge the ammonia that absorbs; Absorption agent can be reuptaked ammonia again, and absorption agent constantly is being able to recycle in the absorption and desorption like this;

(2) need not to regulate the pH value, under acidic conditions, can transform with alkali;

(3) adding of introducing organic denitrifier makes desorb more completely;

(4) catalyzer is installed in ammonia still, is made the ammonia that desorbs be converted into nitrogen rapidly, avoided the secondary pollution that brings to air.

Specific embodiments

Elder generation's coke gas generates DAP and primary ammonium phosphate mixing solutions through in the absorption tower, absorbing with ortho-phosphoric acid after the desulfurization; Constantly circulate mixed solution with lift pump then, absorb ammonia repeatedly, until generating Secondary ammonium phosphate fully; Be passed into the DAP that generates in the ammonia still with pipeline again, add the organic denitrifier of 10～30ppm; Bi-Lu-Y/ β-Fe is installed in ammonia still ₃O ₄Catalyzer; Then in ammonia still, feed steam, Secondary ammonium phosphate resolves into primary ammonium phosphate and ammonia; Last ammonia is reduced into nitrogen under the effect of catalyzer, Secondary ammonium phosphate is squeezed into the absorption cat head with recycle pump, reuptakes the ammonia in the piped gas.

Instance 1

Elder generation's coke gas generates DAP and primary ammonium phosphate mixing solutions through in the absorption tower, absorbing with ortho-phosphoric acid after the desulfurization; Constantly circulate mixed solution with lift pump then, absorb ammonia repeatedly, until generating Secondary ammonium phosphate fully; Be passed into the DAP that generates in the ammonia still with pipeline again, add the organic denitrifier of 10ppm; Bi-Lu-Y/ β-Fe is installed in ammonia still ₃O ₄Catalyzer; Then in ammonia still, feed steam, Secondary ammonium phosphate resolves into primary ammonium phosphate and ammonia; Last ammonia is reduced into nitrogen under the effect of catalyzer, Secondary ammonium phosphate is squeezed into the absorption cat head with recycle pump, reuptakes the ammonia in the piped gas.

Handle certain the ammonia nitrogen concentration 3000mg/L of coke gas factory waste gas with the inventive method, the nitrogen nitrogen concentration drops to 12mg/L from 3000mg/L, and clearance is up to 99.96%.

Instance 2

Elder generation's coke gas generates DAP and primary ammonium phosphate mixing solutions through in the absorption tower, absorbing with ortho-phosphoric acid after the desulfurization; Constantly circulate mixed solution with lift pump then, absorb ammonia repeatedly, until generating Secondary ammonium phosphate fully; Be passed into the DAP that generates in the ammonia still with pipeline again, add the organic denitrifier of 30ppm; Bi-Lu-Y/ β-Fe is installed in ammonia still ₃O ₄Catalyzer; Then in ammonia still, feed steam, Secondary ammonium phosphate resolves into primary ammonium phosphate and ammonia; Last ammonia is reduced into nitrogen under the effect of catalyzer, Secondary ammonium phosphate is squeezed into the absorption cat head with recycle pump, reuptakes the ammonia in the piped gas.

Handle certain the ammonia nitrogen concentration 3000mg/L of coke gas factory waste gas with the inventive method, ammonia nitrogen concentration drops to 40mg/L from 4000mg/L, and clearance is up to 99.9%.

Instance 3

Elder generation's coke gas generates DAP and primary ammonium phosphate mixing solutions through in the absorption tower, absorbing with ortho-phosphoric acid after the desulfurization; Constantly circulate mixed solution with lift pump then, absorb ammonia repeatedly, until generating Secondary ammonium phosphate fully; Be passed into the DAP that generates in the ammonia still with pipeline again, add the organic denitrifier of 20ppm; Bi-Lu-Y/ β-Fe is installed in ammonia still ₃O ₄Catalyzer; Then in ammonia still, feed steam, Secondary ammonium phosphate resolves into primary ammonium phosphate and ammonia; Last ammonia is reduced into nitrogen under the effect of catalyzer, Secondary ammonium phosphate is squeezed into the absorption cat head with recycle pump, reuptakes the ammonia in the piped gas.

Handle certain the ammonia nitrogen concentration 5000mg/L of coke gas factory waste gas with the inventive method, ammonia nitrogen concentration drops to 10mg/L from 5000mg/L, and clearance is up to 99.98%.

Claims

1. method of handling coke gas middle and high concentration ammonia nitrogen is characterized in that:

2. according to the said a kind of method of handling coke gas middle and high concentration ammonia nitrogen of claim 1, it is characterized in that: said organic denitrifier is by Vestolen PP 7052 cyanogen, ethene cyanogen, CH ₃(SiOH) ₃Form, its mass percent is a Vestolen PP 7052 cyanogen 40%～60%, ethene cyanogen 40%～60%, CH ₃(SiOH) ₃10%～20%.

3. according to the said a kind of method of handling coke gas middle and high concentration ammonia nitrogen of claim 1; It is characterized in that: heavy metal content is in oxide mass per-cent in the said catalyzer; Be respectively bismuth oxide 20%～25%, lutecium oxide 15%～20%, yttrium oxide 10%～15%, rhenium oxide 20%～25%, iridium oxide 15%～20%, strontium oxide 13%～20%.