CN1076047C

CN1076047C - Desulfurizing method for systhetic ammonia carbonization system

Info

Publication number: CN1076047C
Application number: CN97108091A
Authority: CN
Inventors: 邓得顺
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-06-02
Filing date: 1997-06-02
Publication date: 2001-12-12
Anticipated expiration: 2017-06-02
Also published as: CN1172148A

Abstract

The present invention discloses a desulphurizing method for a carbonization system produced by synthetic ammonia. The method comprises the steps that zinc granules as desulphurizing agents are added into the carbonization system according to the dosage of 10 to 38 gZ n/Kg H2S; concentrated ammonia liquor containing zinc ions is produced at 0 to 65DEGC under the ammonia concentration of 50 tt to 200 tt; then, hydrogen sulphide is removed to less than 2 ppm in a carbonization tower at 25 50 DEGC and 0.5 to 0.8MPa. The present invention solves the problems of chemical corrosion of carbonization equipment, small ammonium hydrogen carbonate crystallization, gray black color, etc. and has the advantages of little investment, low operation cost, simple flow path, easy operation, etc., and therefore, the present invention is suitable for the desulphurization of the carbonization system produced by synthetic ammonia and is particularly suitable for ammonium hydrogen carbonate producers.

Description

A kind of sulfur method of systhetic ammonia carbonization system

The present invention relates to a kind of sulfur method of systhetic ammonia carbonization system, the sulfur method of the systhetic ammonia carbonization system that especially a kind of bicarbonate of ammonia is produced.

In the prior art, the syngas for synthetic ammonia that bicarbonate of ammonia is produced contains 28% the CO of having an appointment in the conversion gas after the transformationreation of once desulfurization and CO ₂And 0.1g/M ³～0.4g/M ³Sulfide enter carbonization system, make 9～10mol/ with the synthetic gas ammonia of sending here and rise CO in the strong aqua absorption conversion gas ₂With most of sulfide, the bicarbonate of ammonia of generation is as product.Leave CO in the gas of carbonization workshop section ₂Content should be less than 0.2% (volume), H ₂S content should be less than 0.01g/M ³Carbonization system is in purifying the hydrogen sulfide process, and the FeS that not only equipment and pipeline corrosion, and system generates attenuates the fertilizer crystallization, the water content height, and the fertilizer color is black.In order to satisfy the Ammonia Production needs, the hydrogen sulfide content of gas after the carbonization must be taken off to 2PPM.At present, extensively adopt and go here and there dry desulfurization after the carbonization, promptly use gac, zinc oxide, ferric oxide desulfurization, the hydrolysis sweetening agent is done the sorbent material desulfurization, and gac and ferric oxide Sulfur capacity are lower, thus consumption big, change frequent; Use zinc oxide desulfurization and hydrolysis desulfurization, though degree of purification height, complex process and cost height.Shanxi Province chemical research institute delivered in 1978 uses FeSO in carbonated aqueous ammonia ₄Doctor treatment utilizes FeSO ₄The Fe that ionization goes out ⁺And HS ^-Generate the less FeS precipitation of solubility product, be transferred to balanced thrust in the liquid phase to increase hydrogen sulfide in the gas phase, reach the purpose that improves the raw material gas purifying degree, have desulfidation preferably, but it is to equipment corrosion is serious and the crystallization of bicarbonate of ammonia product is little, moisture content is high and color is grey black.

The object of the present invention is to provide a kind of new sulfur method, promptly correspondingly provide a kind of new sweetening agent, with the H of conversion gas ₂S content is reduced to below the 2PPM, and prevents carbonization system equipment corrosion and the bicarbonate of ammonia product of producing good quality.

In order to achieve the above object, the present invention has adopted following technical scheme: promptly adopt zinc ammonia doctor treatment to remove H in the conversion gas ₂S, process comprises: (1) presses 10～38gZn/KgH to carbonization system ₂The cleaner of the amount self-priming ammonia system of S adds zinc granule, at 0～65 ℃, ammonia concentration is that 2.5～10mol/ rises and generates the strong aqua that contains zine ion under the condition, (2) deliver to carbonating tower then, in temperature is that 25～50 ℃, pressure are absorbing carbon dioxide under 0.5～0.8MPa condition, and hydrogen sulfide is taken off to 2PPM.

The present invention's technical scheme preferably can be: the add-on of sweetening agent zinc granule is 20～30g/KgH ₂S, this add-on effect is best, and the add-on of zinc granule is not too high or too low, and the add-on of zinc is if be lower than 10g/KgH ₂S, the weak effect of depriving hydrogen sulphide, and cause etching apparatus, and quality product also is subjected to very big influence, and it is greyish black that its crystallization is little, water content is high and color becomes.In addition, there is no need to add too much sweetening agent zinc granule.

The present invention's technical scheme preferably can also be: inhale ammonia comb exit or one of them place's adding sweetening agent zinc granule of mother liquor tank exit in the suction ammonia comb exit of once circulating, secondary circulation, promptly cleaner (5) can be filled to the exit that one of ammonia comb (4), secondary circulation suction ammonia comb (9) or mother liquor tank (1) are inhaled in once circulation as shown in Figure 1, in cleaner (5), add the zinc granule of metering, all can reach sweetening effectiveness preferably.But its process control condition is different, and promptly temperature is different with ammonia concentration, and concrete data are listed in table 1.

Three kinds of zincification positions of table 1 processing condition

The zincification position	Temperature of reaction (℃)	Ammonia concentration (mol/ liter)
The zincification position	Temperature of reaction (℃)	Ammonia concentration (mol/ liter)	Once the outlet of ammonia comb is inhaled in circulation	28-65	7.5-8.5
Secondary circulation is inhaled the outlet of ammonia comb	30-45	9-10	Once the outlet of ammonia comb is inhaled in circulation	28-65	7.5-8.5
Secondary circulation is inhaled the outlet of ammonia comb	30-45	9-10	The mother liquor tank outlet	0-50	2.5-5

Compared with prior art, the present invention has following tangible advantage:

1, the sweetening agent zinc of the present invention's use is lower than the electronegativity of iron, in ammoniacal liquor than the easier generation electrochemical reaction (electropotential-1.245V of Zn of iron, the electropotential of Fe-0.877V), zinc in ammoniacal liquor can and dissolved oxygen reacts and oxygen is eliminated, effectively suppress carbonizing apparatus and pipeline generation chemical corrosion.

2, deoxygenation resultant Zn (OH) ₂Be easy to generate the ammonia complex that is dissolved in the ammoniacal liquor, the Zn that zinc ammonia complex dissociates out ⁺⁺NH in energy and the ammoniacal liquor ₄The HS that HS ionization is come out ^-Reaction generates the ZnS precipitation littler than FeS solubility product, does not have HS in the ammoniacal liquor substantially ^-, greatly improved the ammoniacal liquor sweetening power, make after the carbonization sulfide content in the gas below 2PPM.

3, the sulfide that uses the zinc desulfurization to generate is white precipitate, has improved the visual appearance of product bicarbonate of ammonia.

4, flow process of the present invention is simple, and easy handling can be regulated the zincification amount arbitrarily according to the height of sulfide content in the conversion gas, guarantees that the sulfide degree of purification in the gas is not subjected to the influence that sulfide raises in the conversion gas after the carbonization.

5, enforcement less investment of the present invention, process cost is low.Throughput is 50,000 tons/year synthesis ammonia plant, guarantee that desulfurization reaches below the 2PPM, is about 10,000 yuan with zinc ammonia process of desulfurization investment, and adopts other method gross investment to reach about 1,500,000 yuan; This law ammonia desulfurization per ton expense is 0.15～0.20 yuan, and ammonia consumption zinc less than 30 grams promptly per ton are that other any sulfur method is incomparable.

Below accompanying drawing of the present invention is made an explanation.

Fig. 1 is a process flow diagram of the present invention, and shown zincification position is in the suction ammonia comb exit of once circulating.Among the figure, 1 in the square frame is mother liquor tank, the 2nd, once inhale ammonia pump, the 3rd, once high-order ammonia absorber, the 4th, once circulate and inhale ammonia comb, the 5th, cleaner, the 6th, circulation groove, the 7th, cyclic ammonia water pump, the 8th, the high-order ammonia absorber of secondary, the 9th, secondary circulation is inhaled ammonia comb, the 10th, strong aqua groove, the 11st, strong aqua pump, the 12nd, carbonization secondary tower, the 13rd, carbonization king-tower, the 14th, stiff device, the 15th, whizzer, the 16th, carbonization comprehensive tower.Its material trend is referring to numbering in the circle, and numbering 1 is to reclaim ammoniacal liquor from three gas in the circle, and the 2nd, low degree of carbonisation weak ammonia, 3, the 4th, mix mother liquor, the 5,6,7,8, the 9th, contain zinc ammoniacal liquor after the deoxygenation, the 10,11,12, the 13rd, the secondary circulation strong aqua, the 14th, give carbodiimide solution, the 15, the 16th, contain the carbodiimide solution of bicarbonate of ammonia, the 17th, mother liquor, the 18th, bicarbonate of ammonia, the 19th, conversion gas, the 20th, king-tower is worked off one's feeling vent one's spleen, and the 21st, secondary tower is worked off one's feeling vent one's spleen, the 22nd, unstripped gas after the carbonization, the 23, the 24th, the gas ammonia that synthetic ammonia is sent here.

Below the present invention is described in further detail by specific embodiment.

Embodiment 1 presses 13gZn/KgH with the sweetening agent zinc granule ₂The amount self purifire 5 of S adds, cleaner 5 is contained in once circulation and inhales ammonia comb 4 exits, from inhaling concentration that the ammonia comb comes out is that 150tt～170tt, temperature are after 30～60 ℃ strong aqua enters cleaner 5 and reacts, enter ammoniacal liquor circulation groove 6, send into high-order ammonia absorber 8 once more with cyclic ammonia water pump 7, continue to absorb the gas ammonia of sending here from the synthetic ammonia post, make the strong aqua of 180tt～200tt, after inhaling 9 coolings of ammonia comb, secondary circulation sends into strong aqua groove 10, to not contain dissolved oxygen with strong aqua pump 11, only contain (Zn (NH ₃) ₄) ⁺⁺And Zn ⁺⁺Strong aqua deliver in the carbonization secondary tower 12 that pressure is 0.5～0.8MPa, absorb carbonization king-tower 13 work off one's feeling vent one's spleen in carbonic acid gas and hydrogen sulfide, the carbodiimide solution that gives that goes out carbonization secondary tower 12 enters carbonization king-tower 13 and continues to absorb umformers In sulfurous gas and hydrogen sulfide, in carbonization king-tower 13, generate bicarbonate of ammonia, the carbodiimide solution that contains bicarbonate of ammonia enters stiff device 14 and leaves standstill for some time, will contain the bicarbonate of ammonia carbodiimide solution then and put into whizzer 15, isolates product carbon ammonium Mother liquor Enter in the mother liquor tank 1 and after the low degree of carbonisation weak ammonia of comprehensive tower 16 mixes, deliver to once the gas ammonia that high-order oxygen inhaler 3 absorptions are sent here from the synthetic ammonia post with a recycle pump 2

The strong aqua of making 150tt～170tt is cooled to 28～65 ℃ through Yi Repetition ring comb 4 and enters in the cleaner 5 circulation of a beginning new round.Gas flow process: by the carbonated 28% that the conversion post is sent here, hydrogen sulfide 0.1～0.4g/M ³Conversion gas enter carbonization king-tower 13, carry out decarbonization, desulfuration reaction, king-tower 13 is worked off one's feeling vent one's spleen and is entered secondary tower 12 usefulness strong aquas and continue to absorb wherein CO ₂And hydrogen sulfide, the gas that goes out secondary tower 12 enters weak ammonia that carbonization comprehensive tower 16 usefulness three gas retrieve and continues to absorb carbonic acid gas and hydrogen sulfide in the tail gas, go out that carbon dioxide content is lower than 0.2% in the unstripped gas of comprehensive tower 16, hydrogen sulfide content is lower than 2PPM and send back workshop section to purify and ammonia synthesis.

The technology controlling and process and the quality product of present embodiment see Table 2.

Embodiment 2～6: cleaner 5 is inhaled ammonia comb 4 exits with example 1 with being contained in once circulation, and working method is with example 1, and technology controlling and process and quality product see Table 2.

Embodiment 7～9: cleaner 5 is contained in secondary circulation and inhales 9 outlets of ammonia comb, and the elementary operation method is with example 1, and technology controlling and process and quality product see Table 2.

Embodiment 10～12: cleaner 5 is contained in mother liquor tank 1 outlet, and the elementary operation method is with example 1, and technology controlling and process and quality product see Table 2.

Table 2 zinc sulfur removal technology control table look-up

Embodiment	Molten zinc temperature ℃	Molten zinc ammonia concn mol/ liter	Advance tower ammoniacal liquor and contain (HS ^-〕％	Advance tower ammonia concn mol/ liter	Advance tower ammoniacal liquor (Zn ⁺⁺) gramion/liter * 10 ^-2	H in the conversion gas ₂S g/M ³	Ammonia per ton is brought H into ₂S g/T	(HS in the carbonating tower ^-) gramion/liter * 10 ^-5	H in the unstripped gas ₂S PPM	Carbon ammonium color	Carbon ammonium moisture content %	Iron rot amount %	Zinc consumption g/KgH ₂S
Embodiment	Molten zinc temperature ℃	Molten zinc ammonia concn mol/ liter	Advance tower ammoniacal liquor and contain (HS ^-〕％	Advance tower ammonia concn mol/ liter		H in the conversion gas ₂S g/M ³	Ammonia per ton is brought H into ₂S g/T	(HS in the carbonating tower ^-) gramion/liter * 10 ^-5	H in the unstripped gas ₂S PPM	Carbon ammonium color	Carbon ammonium moisture content %	Iron rot amount %	Zinc consumption g/KgH ₂S	1	29	8.5	Little	10	0.045	0.07	315	0.053	1.2	Little ash	2.50	Trace	13
2	38	7.95	Do not have	9.85	0.38	0.16	720	0.121	1.1	In vain	2.60	Do not have	36	1	29	8.5	Little	10	0.045	0.07	315	0.053	1.2	Little ash	2.50	Trace	13
2	38	7.95	Do not have	9.85	0.38	0.16	720	0.121	1.1	In vain	2.60	Do not have	36	3	45	7.85	Do not have	9.75	0.35	0.20	900	0.151	1.2	In vain	2.70	Do not have	27.4
4	46	7.5	Do not have	9.9	0.30	0.22	990	0.167	1.2	In vain	2.73	Do not have	23	3	45	7.85	Do not have	9.75	0.35	0.20	900	0.151	1.2	In vain	2.70	Do not have	27.4
4	46	7.5	Do not have	9.9	0.30	0.22	990	0.167	1.2	In vain	2.73	Do not have	23	5	57	8.45	Little	10	0.15	0.26	1170	0.197	1.3	Little ash	2.80	Trace	10.5
6	64	7.9	Do not have	9.7	0.38	0.30	1350	0.227	1.3	In vain	2.80	Do not have	21	5	57	8.45	Little	10	0.15	0.26	1170	0.197	1.3	Little ash	2.80	Trace	10.5
6	64	7.9	Do not have	9.7	0.38	0.30	1350	0.227	1.3	In vain	2.80	Do not have	21	7	30	9.5	Do not have	9.8	0.22	0.15	675	0.114	1	In vain	2.80	Do not have	25
8	35	9.9	Do not have	10	0.33	0.20	900	0.154	1	In vain	2.70	Do not have	27	7	30	9.5	Do not have	9.8	0.22	0.15	675	0.114	1	In vain	2.80	Do not have	25
8	35	9.9	Do not have	10	0.33	0.20	900	0.154	1	In vain	2.70	Do not have	27	9	43	10	Do not have	10	0.53	0.30	1350	0.231	1	In vain	2.80	Do not have	30
10	5	2.65	Little	9.9	0.04	0.08	360	0.062	5	Little ash	3.20	Trace	11	9	43	10	Do not have	10	0.53	0.30	1350	0.231	1	In vain	2.80	Do not have	30
10	5	2.65	Little	9.9	0.04	0.08	360	0.062	5	Little ash	3.20	Trace	11	11	35	3.75	Little	9.85	0.08	0.12	540	0.091	4	Little ash	3.00	Trace	13
12	48	4.9	Little	10	0.12	0.25	1125	0.193	8	Little ash	2.90	Trace	15	11	35	3.75	Little	9.85	0.08	0.12	540	0.091	4	Little ash	3.00	Trace	13

Claims

1, a kind of sulfur method of Ammonia Production carbonization system adds an amount of sweetening agent in carbonization system, desulfurization under certain temperature and ammonia concentration conditions the invention is characterized in and adopts zinc ammonia doctor treatment, and process comprises:

(1) presses 10～38gZn/KgH to carbonization system ₂The cleaner of the amount self-priming ammonia system of S adds zinc granule, is that 2.5～10mol/ rises and generates the strong aqua that contains zine ion under the condition at 0～65 ℃, ammonia concentration, then

(2) delivering to carbonating tower, is that 25～50 ℃, pressure are absorbing carbon dioxide under 0.5～0.8MPa condition in temperature, and sloughing hydrogen sulfide to content is below the 2PPM.

2, sulfur method according to claim 1, the add-on that it is characterized in that the sweetening agent zinc granule is 20～30g/KgH ₂S.

3, sulfur method according to claim 1 and 2 is characterized in that: one of them place of inhaling ammonia comb exit, secondary circulation suction ammonia comb exit or mother liquor tank exit adds sweetening agent zinc granule once circulating.