CN102776034B

CN102776034B - Method for treating high-concentration ammonia and nitrogen in coking gas

Info

Publication number: CN102776034B
Application number: CN201210253321.3A
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: 2014-01-15
Anticipated expiration: 2032-07-18
Also published as: CN102776034A

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 polypropylene cyanide, ethylene cyanide and 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 processing coke gas middle and high concentration ammonia nitrogen

Technical field

The invention discloses a kind of method of processing coke gas middle and high concentration ammonia nitrogen, belong to exhaust-gas treatment field.

Background technology

Coke gas refers to several bituminous coal and is made into coal for coking, in coke oven, after high-temperature retorting, in output tar product, obtains fuel gas, but can produce a large amount of ammonias in concrete production process.People can occur shedding tears after sucking in a short time a large amount of ammonias, pharyngalgia, hoarseness, cough, sputum streaked with blood silk, uncomfortable in chest, expiratory dyspnea, can be with dizzy, headache, feel sick, vomiting, weak etc., can there is pulmonary edema, ARDS in severe patient, respiratory tract symptom may occur simultaneously.If the ammonia sucking is too much, cause ammonia excessive concentration in blood, will cause by the reflex of trigeminal neuralgia tip heart stop fight and breath stopped, threat to life.Long Term Contact ammonia, may there is the symptoms such as Skin pigmentation or finger ulcer in groups of people.

The method of processing at present ammonia mainly contains: physics, chemical and biological method.Physical method is mainly to utilize absorption plant directly to absorb NH ₃.For example: publication number is 102179135A, name is called " a kind of ammonia absorption device " described a kind of absorption plant being comprised of gas-liquid separation buffer, condensate vacuum unit, cooling and absorbing tower, condenser and cistern first NH ₃be condensed into liquid condition, more soluble in water.This method can effectively be removed airborne ammonia, makes it reach discharging standards, but not processing of the high concentration ammoniacal liquor obtaining can cause secondary pollution to environment, and this kind of method power consumption is very high, uneconomical.Chemical method is mainly to utilize acidic materials and NH ₃reaction, absorbs NH ₃.For example: publication number is 1778707, name is called " a kind of high-concentration ammonia nitrogenous wastewater treatment technology " described waste residue or waste liquid containing nitrite anions producing in Chemical Manufacture that utilize, join containing in the waste water of ammonia nitrogen, then drip sulfuric acid solution and regulate the method for the pH value of reaction solution to remove 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 is mainly the nitrification of utilizing microorganism, removes ammonia.For example publication number is 101525179, and name is called the effect of the anaerobic ammonia oxidizing bacteria that " a kind of method of anaerobic ammonia oxidation treatment of low-concentration ammonia nitrogen wastewater " described utilization domestication obtains except the ammonia nitrogen in anhydrating.This method power consumption is high, and needs alkaline environment, impracticable.

Summary of the invention

The present invention is consumed energy high in processing the process of ammonia around prior art, need alkaline environment and can produce secondary pollution problems in processing procedure, provide a kind of can be NH ₃be converted into N ₂method, this method is simply effective, has realized and under lower cost, has carried out catalyzed conversion, this method is used in practice becomes possibility.

In order to achieve the above object, the technical solution used in the present invention is as follows:

(1) coke gas absorbs with orthophosphoric acid in desulfurization Hou absorption tower, generates diammonium hydrogen phosphate and ammonium dihydrogen phosphate (ADP) mixed solution;

(2) then with elevator pump, mixed liquor is constantly circulated, repeatedly absorb ammonia, until generate diammonium hydrogen phosphate completely;

(3) diammonium hydrogen phosphate generating is passed in ammonia still with pipeline, adds the organic denitrifier of 10～30ppm; Described organic denitrifier is by polyacrylonitrile, ethene cyanogen, CH ₃(SiOH) ₃form, its mass percent is polyacrylonitrile 40%～60%, ethene cyanogen 40%～60%, CH ₃(SiOH) ₃10%～20%, above-mentioned its mass percent sum of three kinds of components is 100%;

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

(5) in ammonia still, pass into steam, diammonium hydrogen phosphate resolves into ammonium dihydrogen phosphate (ADP) and ammonia;

(6) ammonia is reduced into nitrogen under the effect of catalyst, and ammonium dihydrogen phosphate (ADP) is squeezed into absorption tower top with circulating pump, reuptakes the ammonia in piped gas.

In described catalyst, content of beary metal, in oxide mass percentage, is respectively bismuth oxide 20%～25%, luteium oxide 15%～20%, yittrium oxide 10%～15%, rheium oxide 20%～25%, yttrium oxide 15%～20%, strontium oxide strontia 13%～20%.

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

(1) take phosphoric acid as absorbent, utilization is under different pH conditions, and phosphoric acid hydrogen radical ion and dihydrogen phosphate ions can transform mutually, thereby the ammonia absorbing is discharged, absorbent can be reuptaked ammonia again, and absorbent is constantly being recycled in absorption and desorption like this;

(2) without regulating pH value with alkali, under acid condition, can transform;

(3) introduce adding of organic denitrifier, make desorb more fully and completely;

(4) catalyst is installed in ammonia still, is made the ammonia desorbing be converted into rapidly nitrogen, avoided the secondary pollution bringing to air.

Specific embodiments

First coke gas absorbs with orthophosphoric acid in desulfurization Hou absorption tower, generates diammonium hydrogen phosphate and ammonium dihydrogen phosphate (ADP) mixed solution; Then with elevator pump, mixed liquor is constantly circulated, repeatedly absorb ammonia, until generate diammonium hydrogen phosphate completely; Again the diammonium hydrogen phosphate generating is passed in ammonia still with pipeline, adds the organic denitrifier of 10～30ppm; Bi-Lu-Y/ β-Fe is installed in ammonia still ₃o ₄catalyst; Then in ammonia still, pass into steam, diammonium hydrogen phosphate resolves into ammonium dihydrogen phosphate (ADP) and ammonia; Last ammonia is reduced into nitrogen under the effect of catalyst, and ammonium dihydrogen phosphate (ADP) is squeezed into absorption tower top with circulating pump, reuptakes the ammonia in piped gas.

Example 1

First coke gas absorbs with orthophosphoric acid in desulfurization Hou absorption tower, generates diammonium hydrogen phosphate and ammonium dihydrogen phosphate (ADP) mixed solution; Then with elevator pump, mixed liquor is constantly circulated, repeatedly absorb ammonia, until generate diammonium hydrogen phosphate completely; Again the diammonium hydrogen phosphate generating is passed in ammonia still with pipeline, adds the organic denitrifier of 10ppm; Bi-Lu-Y/ β-Fe is installed in ammonia still ₃o ₄catalyst; Then in ammonia still, pass into steam, diammonium hydrogen phosphate resolves into ammonium dihydrogen phosphate (ADP) and ammonia; Last ammonia is reduced into nitrogen under the effect of catalyst, and ammonium dihydrogen phosphate (ADP) is squeezed into absorption tower top with circulating pump, reuptakes the ammonia in piped gas.

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

Example 2

First coke gas absorbs with orthophosphoric acid in desulfurization Hou absorption tower, generates diammonium hydrogen phosphate and ammonium dihydrogen phosphate (ADP) mixed solution; Then with elevator pump, mixed liquor is constantly circulated, repeatedly absorb ammonia, until generate diammonium hydrogen phosphate completely; Again the diammonium hydrogen phosphate generating is passed in ammonia still with pipeline, adds the organic denitrifier of 30ppm; Bi-Lu-Y/ β-Fe is installed in ammonia still ₃o ₄catalyst; Then in ammonia still, pass into steam, diammonium hydrogen phosphate resolves into ammonium dihydrogen phosphate (ADP) and ammonia; Last ammonia is reduced into nitrogen under the effect of catalyst, and ammonium dihydrogen phosphate (ADP) is squeezed into absorption tower top with circulating pump, reuptakes the ammonia in piped gas.

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

Example 3

First coke gas absorbs with orthophosphoric acid in desulfurization Hou absorption tower, generates diammonium hydrogen phosphate and ammonium dihydrogen phosphate (ADP) mixed solution; Then with elevator pump, mixed liquor is constantly circulated, repeatedly absorb ammonia, until generate diammonium hydrogen phosphate completely; Again the diammonium hydrogen phosphate generating is passed in ammonia still with pipeline, adds the organic denitrifier of 20ppm; Bi-Lu-Y/ β-Fe is installed in ammonia still ₃o ₄catalyst; Then in ammonia still, pass into steam, diammonium hydrogen phosphate resolves into ammonium dihydrogen phosphate (ADP) and ammonia; Last ammonia is reduced into nitrogen under the effect of catalyst, and ammonium dihydrogen phosphate (ADP) is squeezed into absorption tower top with circulating pump, reuptakes the ammonia in piped gas.

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

Claims

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

(4) Bi-Lu-Y-Re-Ir-Sr/ β-Fe is installed in ammonia still ₃o ₄catalyst, in catalyst, content of beary metal, in oxide mass percentage, is respectively bismuth oxide 20%～25%, luteium oxide 15%～20%, yittrium oxide 10%～15%, rheium oxide 20%～25%, yttrium oxide 15%～20%, strontium oxide strontia 13%～20%;