CN106698344A - Energy saving technical process for ammonia removal of ammonia oxidation synthesis gas - Google Patents

Abstract

The present invention provides an energy saving technical process for ammonia removal of ammonia oxidation synthesis gas, and the process is characterized in that: a combination ammonia removal technical process comprises phosphoric acid or ammonium dihydrogen phosphate primary ammonia removal and sulfuric acid or ammonium hydrogen sulfate fine ammonia removal; the primary ammonia removal of the ammonia oxidation synthesis uses the phosphoric acid or the ammonium dihydrogen phosphate as a carrier, free ammonia in the synthesis gas is absorbed by a primary ammonia removal tower, the phosphoric acid or the ammonium dihydrogen phosphate is converted into diammonium hydrogen phosphate, the free ammonia is desorbed from the diammonium hydrogen phosphate in a desorption column, the diammonium hydrogen phosphate is converted into the ammonium dihydrogen phosphate, and by the repeated circulation, the primary ammonia removal and ammonia recover of the ammonia oxidation synthesis gas can be realized; after the primary ammonia removal, the ammonia oxidation synthesis gas enters a fine ammonia removal tower, the sulfuric acid or the ammonium hydrogen sulfate is used as an absorbent in the fine ammonia removal, residual ammonia in the ammonia oxidation synthesis gas after the primary ammonia removal can be absorbed by the fine ammonia removal tower, the sulfuric acid or the ammonium hydrogen sulfate is converted into ammonium sulfate by-products to achieve the fine ammonia removal of the ammonia oxidation synthesis gas. By combination ammonia removal of the ammonia oxidation synthesis gas, the free ammonia of the ammonia oxidation synthesis gas can be recycled, resources are saved, a true environmentally-friendly ammonia removal process can be achieved, and the energy saving technical process has very good economic and social benefits.

Description

A kind of ammoxidation synthesis gas is except the energy-saving process method of ammonia

Technical field

It is a kind of to be related to ammoxidation synthesis gas except the energy-saving process method of ammonia, refer to be carried out by ammonia source of ammonia Reaction gas of the ammoxidation after its synthesis in free ammonia removal technological process for purifying, fully take into account The recycling of ammonia and the feature of environmental protection of technical process, belong to environment-friendly clean process technical method.

Background technology

Ammoxidation reaction is well known process, and it is in the presence of ammoxidation catalyst, with ammonia and oxygen By can be with the organic matter pyrolytic conversion of ammoxidation as cyanide.The technological value application ratio of ammoxidation reaction If any：By propylene acrylonitrile production, by toluene benzonitrile, by ortho position or paraxylene O-phthalic Nitrile or para-Phthalonitrile, by 3- picolines nicotinonitrile and by methane for hydrogen cyanide and methyl alcohol Hydrogen manufacturing cyanic acid etc.；In the technical process of these technologies, in the forming gas after ammoxidation reaction usually Have considerable amount of free ammonia, these free ammonias need separate or remove after can just carry out product purification or The reaction of lower step operation.In existing industrial production, the removal of the free ammonia in reaction mixture gas is big Many to be removed using sulfuric acid neutralisation, removing works well.But due to being neutralized except ammonia can be produced using sulfuric acid Substantial amounts of ammonium sulfate byproduct, ammonium sulfate is cheap and except ammonia needs to consume substantial amounts of sulfuric acid, ammonia Also it is consumed, it is ineffective；Also many kind and upright men envision using other except ammonia in industry Method, tries hard to utilize recovery ammonia：Such as using phosphoric acid as absorbent, phosphoric acid absorbs free ammonia Change into diammonium hydrogen phosphate, diammonium hydrogen phosphate and ammonium dihydrogen phosphate release ammonia is obtained by parsing again, so that Reach the recycling of ammonia.It is this synthesis gas is realized as carrier using phosphoric acid or ammonium dihydrogen phosphate in dissociate The method of the removal with recycling of ammonia, can to a certain extent obtain advantageous effects, but due to The stability of diammonium hydrogen phosphate is limited；Therefore, synthesis gas is absorbed using phosphoric acid or ammonium dihydrogen phosphate Middle free ammonia its removal completeness can't solve very well, also remain one in the synthesis gas after treatment Determine the free ammonia of content；Especially the temperature of synthesis gas system after treatment is in the case of higher, The content of residual free ammonia can be higher in synthesis gas, is extremely difficult to processing requirement；If treatment temperature control System is than relatively low, then a certain amount of other materials can be dissolved in treatment fluid system, gives parsing pre-treatment And resolving brings other unfavorable factors；Therefore in actual production being greatly limited property, it is impossible to Promote very well.

The content of the invention

For the deficiency of ammoxidation synthesis gas ammonia-removal process technology as described above, ammonia is removed using one kind joint Process, both can be very good to realize the recycling of ammonia, again can be by the free ammonia in synthesis gas Process very thorough, realize the sufficient feature of environmental protection of technical process.

It is an object of the invention to provide a kind of ammoxidation synthesis gas except the energy-saving process method of ammonia, using one Joint is planted except the technology method of ammonia, is to remove ammonia and sulfuric acid or sulphur by phosphoric acid or ammonium dihydrogen phosphate are primary Sour hydrogen ammonium is finely except ammonia is constituted；The primary of ammoxidation synthesis gas removes ammonia, using phosphoric acid or ammonium dihydrogen phosphate Used as carrier, the free ammonia in absorbing synthesis gas in primary ammonia removal column, phosphoric acid or ammonium dihydrogen phosphate turn Diammonium hydrogen phosphate is turned to, diammonium hydrogen phosphate parses free ammonia in Analytic Tower, di(2-ethylhexyl)phosphate is converted into again Hydrogen ammonium, such iterative cycles realize the primary of synthesis gas except ammonia and the recovery of ammonia；Ammoxidation synthesis gas Fine ammonia removal column is entered back into after primary is except ammonia, finely except ammonia is using sulfuric acid or ammonium hydrogen sulfate conduct Absorbent, absorbs the residual ammonia in the primary synthesis gas except after ammonia, sulfuric acid or sulphur in fine ammonia removal column Sour hydrogen ammonium is converted to ammonium sulfate byproduct, and that realizes ammoxidation synthesis gas finely removes ammonia.

In addition to objects, features and advantages described above, also other purposes of the invention, Feature and advantage.Below with reference to figure, the present invention is further detailed explanation.

Brief description of the drawings

The accompanying drawing for constituting the part of the application is used for providing a further understanding of the present invention, the present invention Schematic description and description be used for explain the present invention, do not constitute inappropriate limitation of the present invention.

Fig. 1 is schematic flow sheet of the invention.

Specific embodiment

In order to make the purpose , technical scheme and advantage of the present invention be clearer, below in conjunction with accompanying drawing And embodiment, the present invention will be described in further detail.It should be appreciated that described herein specific Embodiment is only used to explain the present invention, is not intended to limit the present invention.

A kind of ammoxidation synthesis gas removes the technique skill of ammonia using a kind of joint except the energy-saving process method of ammonia Art method, ammonia is removed with sulfuric acid or ammonium hydrogen sulfate finely except ammonia is constituted by phosphoric acid or ammonium dihydrogen phosphate are primary； The primary of ammoxidation synthesis gas removes ammonia, using phosphoric acid or ammonium dihydrogen phosphate as carrier, ammonia is removed in primary The free ammonia in synthesis gas is absorbed in tower, phosphoric acid or ammonium dihydrogen phosphate are converted into diammonium hydrogen phosphate, phosphoric acid The ammonium of hydrogen two parses free ammonia in Analytic Tower, and ammonium dihydrogen phosphate, such iterative cycles reality are converted into again The primary of synthesis gas is showed except ammonia and the recovery of ammonia；Ammoxidation synthesis gas is entered back into after primary is except ammonia Fine ammonia removal column, finely except ammonia is as absorbent, in fine ammonia removal column using sulfuric acid or ammonium hydrogen sulfate The middle residual ammonia absorbed in the primary synthesis gas except after ammonia, sulfuric acid or ammonium hydrogen sulfate are converted to ammonium sulfate pair Product, realize ammoxidation synthesis gas finely removes ammonia.

Presently preferred embodiments of the present invention is the foregoing is only, is not intended to limit the invention, it is all in this hair Within bright spirit and principle, any modification, equivalent substitution and improvements made etc. should be included in Within protection scope of the present invention.

Claims (2)

1. a kind of ammoxidation synthesis gas is except the energy-saving process method of ammonia, it is characterized in that being combined using one kind It is to remove ammonia and sulfuric acid or ammonium hydrogen sulfate by phosphoric acid or ammonium dihydrogen phosphate are primary except the technology method of ammonia Finely except ammonia composition；The primary of ammoxidation synthesis gas removes ammonia, using phosphoric acid or ammonium dihydrogen phosphate as load Body, the free ammonia in absorbing synthesis gas in primary ammonia removal column, phosphoric acid or ammonium dihydrogen phosphate are converted into phosphorus The ammonium of sour hydrogen two, diammonium hydrogen phosphate parses free ammonia in Analytic Tower, ammonium dihydrogen phosphate is converted into again, So iterative cycles realize the primary of synthesis gas except ammonia and the recovery of ammonia；Ammoxidation synthesis gas is by just Level enters back into fine ammonia removal column after removing ammonia, finely except ammonia is to use sulfuric acid or ammonium hydrogen sulfate as absorbent, The residual ammonia in the primary synthesis gas except after ammonia is absorbed in fine ammonia removal column, sulfuric acid or ammonium hydrogen sulfate turn Ammonium sulfate byproduct is changed to, that realizes ammoxidation synthesis gas finely removes ammonia.

2. a kind of ammoxidation synthesis gas described in claim 1 is except the energy-saving process method of ammonia, its feature Apply to related to ammoxidation reaction synthesis gas except ammonia process, such as by propylene acrylonitrile production, by Toluene benzonitrile, examined by ortho position or paraxylene phthalonitrile or para-Phthalonitrile, by 3- skins Quinoline nicotinonitrile and the ammonia such as hydrogen cyanide and methanol ammonoxidation hydrogen manufacturing cyanic acid is prepared by methane ammoxidation Oxidation reaction synthesis gas except ammonia process.