GB1603247A - Production of nitroguanidine from guanidine nitrate by the action of aqueous sulphuric acid - Google Patents
Production of nitroguanidine from guanidine nitrate by the action of aqueous sulphuric acid Download PDFInfo
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- GB1603247A GB1603247A GB19059/78A GB1905978A GB1603247A GB 1603247 A GB1603247 A GB 1603247A GB 19059/78 A GB19059/78 A GB 19059/78A GB 1905978 A GB1905978 A GB 1905978A GB 1603247 A GB1603247 A GB 1603247A
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- sulfuric acid
- acid
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- nitroguanidine
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- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 title claims abstract description 242
- IDCPFAYURAQKDZ-UHFFFAOYSA-N 1-nitroguanidine Chemical compound NC(=N)N[N+]([O-])=O IDCPFAYURAQKDZ-UHFFFAOYSA-N 0.000 title claims abstract description 56
- NDEMNVPZDAFUKN-UHFFFAOYSA-N guanidine;nitric acid Chemical compound NC(N)=N.O[N+]([O-])=O.O[N+]([O-])=O NDEMNVPZDAFUKN-UHFFFAOYSA-N 0.000 title claims abstract description 37
- 235000011149 sulphuric acid Nutrition 0.000 title abstract 7
- 239000001117 sulphuric acid Substances 0.000 title abstract 7
- 238000004519 manufacturing process Methods 0.000 title description 2
- 238000000034 method Methods 0.000 claims abstract description 76
- 239000002253 acid Substances 0.000 claims abstract description 40
- 238000006243 chemical reaction Methods 0.000 claims abstract description 19
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 9
- 230000018044 dehydration Effects 0.000 claims abstract description 3
- 238000006297 dehydration reaction Methods 0.000 claims abstract description 3
- 239000011541 reaction mixture Substances 0.000 claims description 36
- 239000007791 liquid phase Substances 0.000 claims description 30
- 238000001704 evaporation Methods 0.000 claims description 18
- 230000008020 evaporation Effects 0.000 claims description 14
- 239000007790 solid phase Substances 0.000 claims description 12
- 239000002699 waste material Substances 0.000 claims description 10
- 239000003085 diluting agent Substances 0.000 claims description 9
- 238000001816 cooling Methods 0.000 claims description 7
- 238000005406 washing Methods 0.000 claims description 7
- 238000007865 diluting Methods 0.000 claims description 6
- 238000000926 separation method Methods 0.000 claims description 6
- 238000010924 continuous production Methods 0.000 claims description 4
- 239000012535 impurity Substances 0.000 claims description 4
- 238000006396 nitration reaction Methods 0.000 claims description 4
- 230000001376 precipitating effect Effects 0.000 claims description 3
- -1 84% Chemical compound 0.000 claims description 2
- BIGPRXCJEDHCLP-UHFFFAOYSA-N ammonium bisulfate Chemical compound [NH4+].OS([O-])(=O)=O BIGPRXCJEDHCLP-UHFFFAOYSA-N 0.000 claims description 2
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 2
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 2
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 2
- 239000013505 freshwater Substances 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 239000012071 phase Substances 0.000 claims description 2
- 230000035484 reaction time Effects 0.000 claims description 2
- 239000011369 resultant mixture Substances 0.000 claims description 2
- 238000003756 stirring Methods 0.000 claims description 2
- 238000010923 batch production Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Nitroguanidine is prepared from guanidine nitrate by the action of aqueous sulphuric acid and, optionally, nitric acid. In this process the reconcentrated sulphuric acid obtained from the preceding step is used, the reaction being carried out using from 2.5 to 3.5 mol of sulphuric acid per mol of guanidine nitrate. The dehydration is carried out using from 82 to 85 % by weight strength sulphuric acid at a temperature of from 40 to 80 DEG C, preferably from 40 to 60 DEG C, for from 1 to 3 hours. The sulphuric acid is then diluted, by adding water or wash acid at 0 to 5 DEG C from a previous step, to from 25 to 35 % strength by weight. After the nitroguanidine which has precipitated has been separated off, the sulphuric acid diluted to from 25 to 35 % strength by weight is reconcentrated to be used again.
Description
(54) PRODUCTION OF NITROGUANIDINE FROM GUANIDINE
NITRATE BY THE ACTION OF AQUEOUS SULFURIC ACID
(71) We, INDUSTRIE CHEMIE
THOMA GMBH & CO. BETEILIGUNGS KG, of 2 Beuthener Strasse, D-8264 Waldkraiburg, Federal Republic of Germany, a German company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a process for producing ntiroguanidine from guanidine nitrate.
In a well Imown process for producing nitroguanidine from guanidine nitrate, the process is carried out with sulfuric acid having a strength in the range 75 to 85 w/w, for a period of 4 to 24 hours and at a temperature of 25 to 350C. The reaction mixture is thereafter diluted to a concentration of 25 to 30 O,o v/v of sulfuric acid.
The dilution is carried out with water or with wash-acid containing 2 to 5% v/v of sulfuric acid from another step. The nitroguanidine is precipitated in a temperature range of 18 to 25"C. The sulfuric acid is recovered and concentrated for reuse in the next batch. It is a disadvantage of said known process that when chosing a reaction temperature not exceeding 350C, the reaction period will amount to 4 to 24 hours if as much as 9800 w/w of nitroguanidine is to be recovered.
According to a first aspect of the present invention, there is provided a process for producing nitroguanidine from guanidine nitrate, comprising:
(a) reacting guanidine nitrate with sulfuric acid to give a reaction mixture containing nitroguanidine, said sulfuric acid having any strength in the range 82 to 85% w/w, and said reacting being carried out at any reaction temperature in the range 40 to 80"C; (b) diluting said reaction mixture of step (a) to give a diluted reaction mixture containing sulfuric acid having any strength in the range 25 to 35 % w/w, said diluting being carried out with aqueous diluent;
(c) precipitating nitroguanidine in said diluted reaction mixture of step (b) to give a solid phase comprising precipitated nitroguanidine, and a liquid phase comprising sulfuric acid; and
(d) separating said solid and liquid phases of step (c).
According to a second aspect of the present invention, there is provided nitroguanidine prepared by said process according to the first aspect of the present invention.
According to a third aspect of the present invention, there is provided sulfuric acid recovered in said process according to the first aspect of the present invention.
In carrying out step (a), sulfuric acid can be reacted with guanidine nitrate in any mole ratio in the range 2.5 to 3.5 moles of sulfuric acid to 1 mole of guanidine nitrate. Step (a) can be carried out using guanidine nitrate in an amount of 0.25 to 0.3 part by weight per part by weight of sulfuric acid. Guanidine nitrate used in the present invention can be substantially 95% w/w pure or substantially 98"j, w/wtpure, for convenience.
In step (a), said reaction temperature can be a temperature in the range 40 to 600C, e.g. substantially 50"C. Step (a) can be carried out for any time in the range 1 to 3 hours (contrast with the 4 to 24 hours in said well known process). In step (a), guanidine nitrate can be added to sulfuric acid. In step (a), the sulfuric acid used can comprise waste sulfuric acid and fresh sulfuric acid. In step (a), said waste sulfuric acid can comprise concentrated said liquid phase or step (d). In step (a), said waste sulfuric acid can have a strength in the range 75 to 82% w/w, or a strength in the range 80 to 820/ó w/w. In step (a), the sulfuric acid used can be such that an amount 10 to 25% v/v of said concentrated liquid phase of step (d) has been replaced by fresh sulfuric acid. In step (a), the sulfuric acid used can comprise 20 to 25 ó v/v of said fresh sulfuric acid. Said fresh sulfuric acid can have a strength in the range 96 to 98% w/w, or in the range 97 to 98% w/w. Said fresh sulfuric acid can comprise oleum. In step (a), nitric acid can be present.
In step (a), said sulfuric acid can contain 3 to 10% v/v of concentrated nitric acid.
Step (a) can reduce the strength of said sulfuric acid to a strength in the range 79 to 82% w/w.
In step (b), said aqueous diluent can have a temperature in the range 0 to 50C. In step (b), said aqueous diluent can comprise water. In step (b), said aqueous diluent can comprise wash-acid. The expression "wash-acid" refers to water used and/or partly reused for washing nitroguanidine in or after step (d). The wash-acid can contain 3 to 10% v/v of sulfuric acid. The wash-acid can be partly used in step (b) to give sulfuric acid having a strength in the range 25 to 35% w/w.
Step (c) can comprise cooling said solid and liquid phases. In step (c), said cooling can be to a temperature in the range 0 to 3"C.
Step (d) can comprise centrifuging said solid and liquid phases to separate those phases. In step (d), said separated solid phase can be washed (cf. said wash-acid) to remove impurities from nitroguanidine. In step (d), said separated liquid phase can contain some nitroguanidine.
The process according to said first aspect of the invention can comprise the further step of (e) concentrating said separated liquid phase of step (d). In step (e), said concentrating can comprise partly evaporating said separated liquid phase of step (d). In step (e), said partial evaporation can be carried out under reduced pressure. In step (e), said partial evaporation can be carried out at an evaporation temperature not exceeding substantially 1400C, e.g. said evaporation temperature can be a temperature in the range 100 to 1400C. In step (e), said partial evaporation can be carried out in rotary evaporator means, e.g. a plurality of rotary evaporators connected in series, for instance three said rotary evaporators connected in series. In step (e), the residence time of said evaporating liquid phase in the last rotary evaporator in said series e.g. does not exceed a time in the range 5 to 10 minutes and the evaporation temperature is e.g. in the range 100 to 1400C. In step (e), said concentrated, separated liquid phase can provide sulfuric acid having any strength in the range 80 to 85% w/w, or in the range 82 to 85% w/w, or in the range 80 to 82% w/w.
The process according to said first aspect of the present invention can comprise the further step (f) of using as at least a portion - of said sulfuric acid of step (a) said concentrated, separated liquid phase of step (e).
Said waste acid can be provided by said concentrated, separated liquid phase of step (e).
Said steps of the process according to the first aspect of the present invention can be operated at least partly continuously or discontinuously.
In one embodiment of the present invention, there is provided a process for the continuous production of nitroguanidine from guanidine nitrate by the action of aqueous sulfuric acid possibly with nitric acid, comprising reusing concentrated sulfuric acid recovered from a previous step, wherein the conversion is carried out using 2.5 to 3.5 moles of sulfuric acid per mole of guanidine nitrate, characterised by that dehydration is carried out using 82 to 85% w/w strength sulfuric acid at a temperature of 40 to 80or, preferably 40 to 600C, in a period of 1 to 3 hours and subsequently the sulfuric acid is diluted to 25 to 35% v/v by adding water or wash acid at a temperature of O to 5"C from a previous operation and the 25 to 35% v/v sulfuric acid recovered after separation of precipitated nitroguanidine is concentrated for reuse. The concentration of the recovered 25 to 35% v/v sulfuric acid can be performed up to e.g. 80 to 82% w/w strength, and 10 to 25% v/v of this concentrated acid can be replaced by 97 to 9896 w/w strength sulfuric acid or oleum, and the sulfuric acid can be reused in a concentration of 82 to 85% w/w strength.
The concentration of the 25 to 35% v/v sulfuric acid up to 80 to 82% w/w strength can be carried out in a plurality of rotary evaporators connected in series, under reduced pressure and a maximum temperature of 1400C and that in the last, preferably in the third of three rotary evaporators in series, the residence time of the acid which is at a temperature of 100 to 140"C does not exceed 10 minutes, e.g. that residence time does not exceed 5 minutes.
The present invention will now be illustrated by the following Examples.
Example 1 (Batch Production).
0.25 to 0.30 part by weight of guanidine nitrate of 980ó w/w purity is added to one part by weight of sulfuric acid of 82 to 85% w/w strength. This acid consists of 75 to 90%, v/v of 75 to 82% w/w strength concentrated waste sulfuric acid and 10 to 25eco v/v of fresh sulfuric acid of 96 to 98 w/w strength (or oleum), possibly containing 3 to 10% v/v of concentrated nitric acid. The addition of the guanidine nitrate is within a period of one hour beginning at room temperature. Cooling is provided but the temperature of the reaction mixture is allowed to rise to 500C. The guanidine nitrate dissolves in the reaction mixture, and is available for conversion into nitroguanidine.
The reaction reduces the sulfuric acid concentration by about 3% v/v to 79 to 82or, v/v.
After the one hour period, the reaction will be completed in a further one or two hours. The reaction mixture is then mixed with wash-acid containing 3 to 10% v/v of sulfuric acid at a temperature in the range 0 to 5"C. Sulfuric acid of strength 25 to 35 Xw w/w is thereby produced in the reaction mixture, and precipitated nitroguanidine is suspended in that acid. The reaction mixture is then cooled to 0 to 3 C, and the nitroguanidine is separated by means of a centrifuge. Subsequently, washings are made with wash-acid, and finally with fresh water until the nitroguanidine is free of sulfuric acid.
The wash acid can be from previous batch operation of the process of the present invention.
The first centrifuged separated sulfuric acid of 25 to 35two w/w strength contains about 0.5 to 2.09o w/w of nitroguanidine, and 1 to 4% w/w of ammonium sulfate and ammonium bisulfate, and other impurities in dissolved form. The separated acid is partly evaporated in three rotary evaporators connected in series, whereby that acid is distilled under reduced pressure and to an end temperature up to a maximum of 140"C.
The residence time in the three rotary evaporators, particularly in the last one, is only a few minutes in each case. The partial evaporation gives 82 to 85% w/w strength sulfuric acid as water-clear product. 10 to 25 ó v/v of this acid is removed after each nitration cycle and replaced by the same quantity of concentrated fresh sulfuric acid or oleum. By this method, sulfuric acid returned to the nitration cycle can suitable in composition, and for this reason the product nitroguanidine can always have the same desired consistency. Thus, sulfuric acid can be permanently circulated without necessity to remove it as a whole.
The product nitroguanidine can have a purity of at least 98.5% weight. The yield of product nitroguanidine can be about 97 to 98% weight of the theoretical yield calculated on the basis of the total weight of guanidine nitrate used.
Example 2 (At Least Semi-Continuous Production).
In this Example, three reactors in series are used, each of 4,000 litres capacity. In a period of one hour, 1,250 kgs of guanidine nitrate at a temperature of 40 to 50"C are pumped into the first reactor. In the same period, 4,200 kgs of 82 to 85% w/w strength sulfuric acid (e.g. 84%, w/w strength) at a temperature of 10 to 30"C are pumped into the first reactor. The reaction mixture produced in the first reactor is kept to 40 to 60go, by stirring and cooling.
At intervals of one hour, the total reaction mixture in the first reactor is pumped into the second reactor. Also, at intervals of one hour, the total reaction mixture in the second reactor is pumped into the third reactor.
Thus, a total reaction time of 3 hours for the conversion to nitroguanidine can be achieved. When reaction mixture is pumped from the third reactor, the first reactor can be refilled. Reaction mixture can thereby be pumped from the third reactor with the volume of the contents in the first reactor maintained practically constant. All three reactors can be filled to 60 to 90% of their volume capacities.
The reaction mixture obtained from the third reactor contains sulfuric acid of 25 to 35% w/w strength. 75 to 90% v/v of this acid is concentrated to a strength of 82 to 85 ó w/w. This concentrated acid is then mixed with 10 to 25% v/v of fresh sulfuric acid of 96 to 98% w/w strength (or oleum), possibly containing 3 to 10% v/v of concentrated nitric acid. The resultant mixture can be used as the sulfuric acid in the first reactor. The 25 to 35% w/w strength sulfuric acid from the third reactor is separated from the precipitated nitroguanidine, and the separated sulfuric acid is concentrated as mentioned above. For that separation, the reaction mixture from the third reactor is cooled to 0 to 50C and then subjected to separation in a centrifuge. The separated nitroguanidine is washed free of sulfuric acid, thereby providing wash-acid. Wash-acid from previous washings can be used in washing the nitroguanidine, followed by water.
WHAT WE CLAIM IS:- 1. A process for producing nitroguanidine from guanidine nitrate, comprising:
(a) reacting guanidine nitrate with sulfuric acid to give a reaction mixture containing nitroguanidine, said sulfuric acid having any strength in the range 82 to 85 /ó w/w, and said reacting being carried out at any reaction temperature in the range 40 to 800C; (b) diluting said reaction mixture of step (a) to give a diluted reaction mixture containing sulfuric acid having any strength in the range 25 to 35% w/w, said diluting being carried out with aqueous diluent;
(c) precipitating nitroguanidine in said diluted reaction mixture of step (b) to give a solid phase comprising precipitated nitroguanidine, and a liquid phase comprising sulfuric acid; and
(d) separating said solid and liquid phases of step (c).
2. A process as claimed in claim 1, wherein
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (54)
1. A process for producing nitroguanidine from guanidine nitrate, comprising:
(a) reacting guanidine nitrate with sulfuric acid to give a reaction mixture containing nitroguanidine, said sulfuric acid having any strength in the range 82 to 85 /ó w/w, and said reacting being carried out at any reaction temperature in the range 40 to 800C; (b) diluting said reaction mixture of step (a) to give a diluted reaction mixture containing sulfuric acid having any strength in the range 25 to 35% w/w, said diluting being carried out with aqueous diluent;
(c) precipitating nitroguanidine in said diluted reaction mixture of step (b) to give a solid phase comprising precipitated nitroguanidine, and a liquid phase comprising sulfuric acid; and
(d) separating said solid and liquid phases of step (c).
2. A process as claimed in claim 1, wherein
in step (a) sulfuric acid is reacted with guanidine nitrate in any mole ratio in the range 2.5 to 3.5 moles of sulfuric acid to 1 mole of guanidine nitrate.
3. A process as claimed in claim 1 or 2, wherein step (a) is carried out using guanidine nitrate in an amount of 0.25 to 0.3 part by weight per part by weight of sulfuric acid.
4. A process as claimed in any one of claims 1 to 3, wherein said guanidine nitrate is substantially 95% w/w pure.
5. A process as claimed in any one of claims 1 to 3, wherein said guanidine nitrate is substantially 98% w/w pure.
6. A process as claimed in any one of claims 1 to 5, wherein in step (a) said reaction temperature is a temperature in the range 40 to 600C.
7. A process as claimed in claim 6, wherein in step (a) said reaction temperature is substantially 50"C.
8. A process as claimed in any one of claims 1 to 7, wherein step (a) is carried out for any time in the range 1 to 3 hours.
9. A process as claimed in any one of claims 1 to 8, wherein in step (a) said guanidine nitrate is added to said sulfuric acid.
10. A process as claimed in any one of claims 1 to 9, wherein in step (a) the sulfuric acid used comprises waste sulfuric acid and fresh sulfuric acid.
11. A process as claimed in claim 10, wherein in step (a) said waste sulfuric acid comprises concentrated said liquid phase of step (d).
12. A process as claimed in claim 10 or 11, wherein in step (a) said waste sulfuric acid has a strength in the range 75 to 82% w/w.
13. A process as claimed in claim 10 or 11, wherein in step (a) said waste sulfuric acid has a strength in the range 80 to 82% w/w.
14. A process as claimed in any one of claims 11 to 13, wherein in step (a) in the sulfuric acid used an amount 10 to 25% v/v of said concentrated liquid phase of step (d) has been replaced by fresh sulfuric acid.
15. A process as claimed in any one of claims 11 to 14, wherein in step (a) the sulfuric acid used comprises 20 to 25% v/v of said fresh sulfuric acid.
16. A process as claimed in any one of claims 10 to 15, wherein in step (a) said fresh sulfuric acid has a strength in the range 96 to 98 ó w/w.
17. A process as claimed in any one of claims 10 to 15, wherein in step (a) said fresh sulfuric acid has any strength in the range 97 to 98% w/w.
18. A process as claimed in any one of claims 10 to 17, wherein in step (a) said fresh sulfuric acid comprises oleum.
19. A process as claimed in any one of claims 10 to 18, wherein in step (a) nitric acid is present.
20. A process as claimed in claim 19, where
in in step (a) said sulfuric acid contains 3 to 10% v/v of concentrated nitric acid.
21. A process as claimed in any one of claims 1 to 20, wherein step (a) reduces the strength of said sulfuric acid to a strength in the range 79 to 82% w/w.
22. A process as claimed in any one of claims 1 to 21, wherein in step (b) said aqueous diluent has a temperature in the range 0 to 5 C.
23. A process as claimed in any one of claims 1 to 22, wherein in step (b) said aqueous diluent is water.
24. A process as claimed in any one of claims 1 to 22, wherein in step (b) said aqueous diluent comprises wash-acid.
25. A process as claimed in claim 24, wherein in step (b) said wash-acid contains 3 to 10% v/v of sulfuric acid.
26. A process as claimed in any one of claims 1 to 25, wherein step (c) comprises cooling said solid and liquid phases.
27. A process as claimed in claim 26, wherein in step (c) said cooling is to a temperature in the range 0 to 30C.
28. A process as claimed in any one of claims 1 to 27, wherein step (d) comprises centrifuging said solid and liquid phases to separate those phases.
29. A process as claimed in any one of claims 1 to 28, wherein in step (d) said separated solid phase is washed to remove impurities from nitroguanidine.
30. A process as claimed in any one of claims 1 to 29, wherein in step (d) said separated liquid phase contains some nitroguanidine.
31. A process as claimed in any one of claims 1 to 30, comprising (e) concentrating said separated liquid phase of step (d).
32. A process as claimed in claim 31, wherein in step (e) said concentrating comprises partly evaporating said separated liquid phase of step (d).
33. A process as claimed in claim 32, wherein in step (e) said partial evaporation is carried out under reduced pressure.
34. A process as claimed in claim 32 or 33, wherein in step (e) said partial evaporation is carried out at an evaporation temperature not exceeding substantially 140"C.
35. A process as claimed in claim 34, wherein in step (e) said evaporation temperature is a temperature in the range 100 to 1400C.
36. A process as claimed in any one of claims 32 to 35, wherein in step (e) said partial evaporation is carried out in rotary evaporator means.
37. A process as claimed in claim 36, wherein in step (e) said rotary evaporator means comprises a plurality of rotary evaporators connected in series.
38. A process as claimed in claim 37, wherein in step (e) there are three said said rotary evaporators connected in series.
39. A process as claimed in claim 37 or 38, wherein in step (e) the residence time of said evaporating liquid phase in the last rotary evaporator in said series does not exceed a time in the range 5 to 10 minutes and the evaporation temperature is in the range 100 to 1400C.
40. A process as claimed in any one of claims 31 to 39, wherein in step (e) said concentrated, separated liquid phase provides sulfuric acid having any strength in the range 80 to 85% w/w.
41. A process as claimed in any one of claims 31 to 39, wherein in step (e) said concentrated, separated liquid phase provides sulfuric acid having a strength in the range 82 to 85% w/w.
42. A process as claimed in any one of claims 31, to 39, wherein in step (e) said concentrated, separated liquid phase provides sulfuric acid having strength in the range 80 to 82% sr/w
43. A process as claimed in any one of claims 31 to 39, comprising (f) using as at least a portion of said sulfuric acid of step (a) said concentrated, separated liquid phase of step (e).
44. A process as claimed in claim 43, when according to any one of claims 10 to 20, wherein said waste acid is provided by said concentrated, separated liquid phase of step (e).
45. A process as claimed in any one of claims 1 to 44, wherein said steps are operated at least partly continuously.
46. A process as claimed in any one of claims 1 to 44, wherein said steps are operated discontinuously.
47. A process for producing nitroguanidine from guanidine nitrate, said process being substantially as described in Example 1.
48. A process for producing nitroguanidine from guanidine nitrate, said process being substantially as described in Example 2.
49. Nitroguanidine prepared by a process as claimed in any one of claims 1 to 53.
50. Sulfuric acid recovered in a process as claimed in any one of claims 1 to 48.
51. A process for the continuous production of nitroguanidine from guanidine nitrate by the action of aqueous sulfuric acid possibly with nitric acid, comprising reusing concentrated sulfuric acid recovered from a previous step wherein the conversion is carried out using 2.5 to 3.5 moles of sulfuric acid per mole of guanidine nitrate, characterised by that dehydration is carried out using 82 to 85 % w/w strength sulfuric acid at a temperature of 40 to 80 , preferably 40 to 600C, in a period of 1 to 3 hours and subsequently the -sulfuric acid is diluted to 25 to 35% v/v by adding water or wash-acid at a temperature of 0 to 5 C from a previous operation and the 25 to 35% v/v sulfuric acid recovered after separation of precipitated nitroguanidine is concentrated for reuse.
52. A process according to claim 51, characterised by that the concentration of the recovered 25 to 35% v/v sulfuric acid is performed up to 80 to 82% w/w strength, and 10 to 25% v/v of this concentrated acid is replaced by 97 to 98% w/w strength fresh sulfuric acid or oleum, and the sulfuric acid is reused in a concentration of 82 to 85 % w/w strength.
53. A process according to claim 52, characterised by that the concentration of the 25 to 35% v/v sulfuric acid up to 80 to 82% w/w strength is carried out in a plurality of rotary evaporators connected in series, under reduced pressure and a maximum temperature of 140"C and that in the last, preferably in the third of three rotary evaporators in series, the residence time of the acid which is at a temperature of 100 to 1400C does not exceed 10 minutes.
54. A process according to claim 53, characterised by that said residence time does not exceed 5 minutes.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19772745783 DE2745783C3 (en) | 1977-10-12 | 1977-10-12 | Production of nitroguanidine from guanidine nitrate under the action of aqueous sulphuric acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1603247A true GB1603247A (en) | 1981-11-18 |
Family
ID=6021217
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB19059/78A Expired GB1603247A (en) | 1977-10-12 | 1978-05-11 | Production of nitroguanidine from guanidine nitrate by the action of aqueous sulphuric acid |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS5849538B2 (en) |
| AT (1) | AT359081B (en) |
| BE (1) | BE867685A (en) |
| CA (1) | CA1105489A (en) |
| CH (1) | CH634827A5 (en) |
| DE (1) | DE2745783C3 (en) |
| FR (1) | FR2405929A1 (en) |
| GB (1) | GB1603247A (en) |
| IN (1) | IN148716B (en) |
| IT (1) | IT1096260B (en) |
| NL (1) | NL7803712A (en) |
| ZA (1) | ZA781967B (en) |
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| CN105152984A (en) * | 2015-09-02 | 2015-12-16 | 南通天泽化工有限公司 | Continuous synthetic method of nitroguanidine |
| CN111675634A (en) * | 2020-07-17 | 2020-09-18 | 宁夏东吴农化股份有限公司 | Preparation method of nitroguanidine |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE964411C (en) * | 1939-03-23 | 1957-05-23 | Bayerische Stickstoff Werke Ge | Process for the production of nitroguanidine from guanidine nitrate |
| GB572931A (en) * | 1941-06-26 | 1945-10-30 | American Cyanamid Co | Improvements in or relating to the preparation of nitro-guanidine |
| DE1234204B (en) * | 1963-01-09 | 1967-02-16 | M Thoma | Process for the production of nitroguanidine from guanidine nitrate |
-
1977
- 1977-10-12 DE DE19772745783 patent/DE2745783C3/en not_active Expired
-
1978
- 1978-04-06 ZA ZA00781967A patent/ZA781967B/en unknown
- 1978-04-07 CH CH378878A patent/CH634827A5/en not_active IP Right Cessation
- 1978-04-07 NL NL7803712A patent/NL7803712A/en not_active Application Discontinuation
- 1978-04-11 CA CA300,926A patent/CA1105489A/en not_active Expired
- 1978-04-26 AT AT299978A patent/AT359081B/en active
- 1978-05-03 IT IT22979/78A patent/IT1096260B/en active
- 1978-05-04 IN IN488/CAL/78A patent/IN148716B/en unknown
- 1978-05-11 GB GB19059/78A patent/GB1603247A/en not_active Expired
- 1978-05-11 FR FR7814995A patent/FR2405929A1/en active Granted
- 1978-05-31 BE BE188220A patent/BE867685A/en not_active IP Right Cessation
- 1978-10-06 JP JP12406978A patent/JPS5849538B2/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112920091A (en) * | 2020-12-31 | 2021-06-08 | 宁夏天泽新材料科技有限公司 | Preparation process of nitroguanidine |
| CN115160188A (en) * | 2022-07-06 | 2022-10-11 | 贝利特化学股份有限公司 | Method for preparing nitroguanidine in micro-channel |
| CN115160188B (en) * | 2022-07-06 | 2024-01-16 | 贝利特化学股份有限公司 | Method for preparing nitroguanidine in micro-channel |
Also Published As
| Publication number | Publication date |
|---|---|
| NL7803712A (en) | 1979-04-18 |
| FR2405929B1 (en) | 1983-12-23 |
| BE867685A (en) | 1978-09-18 |
| CA1105489A (en) | 1981-07-21 |
| DE2745783B2 (en) | 1981-01-22 |
| IT1096260B (en) | 1985-08-26 |
| ZA781967B (en) | 1979-06-27 |
| ATA299978A (en) | 1980-03-15 |
| JPS5849538B2 (en) | 1983-11-05 |
| AT359081B (en) | 1980-10-27 |
| IT7822979A0 (en) | 1978-05-03 |
| DE2745783A1 (en) | 1979-04-19 |
| JPS5461122A (en) | 1979-05-17 |
| CH634827A5 (en) | 1983-02-28 |
| DE2745783C3 (en) | 1987-09-10 |
| IN148716B (en) | 1981-05-23 |
| FR2405929A1 (en) | 1979-05-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19940511 |