CN105984888A - Process for preparing hydrogen cyanamide by utilizing urea - Google Patents
Process for preparing hydrogen cyanamide by utilizing urea Download PDFInfo
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- CN105984888A CN105984888A CN201510084237.7A CN201510084237A CN105984888A CN 105984888 A CN105984888 A CN 105984888A CN 201510084237 A CN201510084237 A CN 201510084237A CN 105984888 A CN105984888 A CN 105984888A
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Abstract
The invention discloses a process for preparing hydrogen cyanamide by utilizing urea. The process includes the following steps that 1, a manganese acetate solution and an HZSM-5 molecular sieve are used for preparing a catalyst by adopting an ion exchange method; 2, after urea particles are heated to reach 500-550 DEG C under the ammonia atmosphere, the urea particles and the catalyst preheated to reach 500-550 DEG C perform mixed reaction; 3, a product obtained in the step 2 is cooled to reach 40-45 DEG C, carbon dioxide and ammonia in the product are absorbed by using dilute sulfuric acid and a sodium hydroxide water solution, and then filtration is performed; 4, extraction is performed: ethyl acetate is utilized to extract filtrate obtained in the step 3, and then filtration, washing, re-crystallization and drying are performed to obtain hydrogen cyanamide. The process adopts the aluminum silicon catalyst to catalyze the urea and prepare the hydrogen cyanamide through dehydration, is not only simple, but also is low in energy consumption and small in pollution, generated by-products are greatly decreased, the selectivity of the hydrogen cyanamide is improved, and an application prospect is wide.
Description
Technical field
The present invention relates to chemical field, specifically a kind of technique utilizing urea to prepare cyanamide.
Background technology
Cyanamide is not only a kind of important industrial chemicals, organic chemical industry's intermediate, or a kind of very important medical material, can be used as noresidue, low toxicity, phosphoramidite chemical pesticide intermediate.In addition, cyanamide can be additionally used in the synthesis etc. of health product, the synthesis of feed addictive and fire retardant, purposes is widely.The industrial process of cyanamide is mainly lime nitrogen method, this method complex process, and equipment investment is big, seriously polluted, energy consumption is high, containing more free state calcium carbide in product.The raw material lime nitrogen that lime nitrogen method is used is prepared by calcium carbide high-temperature ammonolysis, and the therefore production of lime nitrogen is a high energy consumption, high pollution, the conventional industries of maximum discharge, is also the pollution source that deep processing produces.Meanwhile, produce lime nitrogen and not only can produce volume of smoke, and a large amount of available waste heat is with soot emissions, not only pollutes environment but also waste resource, and the control of process condition requires more strict.With the propelling of new industrialization and national resources comprehensively utilize, Environment Protection Policy regulation perfect, the extensive style of calcium carbide deep processed product is survived hard to carry on, will be replaced by new technology.
Content of the invention
It is an object of the invention to provide a kind of technique utilizing urea to prepare cyanamide, not only technique is simple, and energy consumption is low, it is little to pollute, and greatly reduces the generation of accessory substance (mainly a small amount of melamine), improves the selectivity of cyanamide.
For achieving the above object, the present invention provides following technical scheme:
A kind of technique utilizing urea to prepare cyanamide, concretely comprises the following steps:
(1) preparation of catalyst: use ion-exchange to prepare catalyst manganese acetate solution and HZSM-5 type molecular sieve；
(2) dehydration: under ammonia atmosphere, after urea granules is heated to 500-550 DEG C, mixes with the catalyst being preheating to 500-550 DEG C and reacts；
(3) cooling, filtration: the product that step (2) obtains is cooled to 40-45 DEG C, after using dilute sulfuric acid and sodium hydrate aqueous solution to absorb the carbon dioxide in product and ammonia, the filtrate being filtrated to get is cyanamide solution；
(4) extract: after utilizing ethyl acetate to extract the cyanamide solution that step (3) obtains, filter, washing, recrystallization, it is dried to obtain cyanamide.
As the further scheme of the present invention: described step (1) is divided into following little step:
1) the manganese acetate solution preparation of 0.2mol/L: manganese acetate four crystalline of the manganese acetate solid or 49.02g that first weigh 34.6g adds in reactor, the HZSM-5 type molecular sieve weighing 100g again adds in reactor, then in reactor, 1L distilled water is added so that it is mix；
2) heat: use water-bath mode that reactor is heated to 75-78 DEG C, be incubated 3-4h；
3) filter: the insulation of question response device terminates, use vavuum pump to carry out suction filtration to the solution in reactor, then wash with distilled water；
4) re-dissolved: weigh the manganese acetate solid of 34.6g or manganese acetate four crystalline of 49.02g, together joins in reactor together with the material after step 3) washing, then adds 1L distilled water in reactor so that it is mix；
5) reheat: use water-bath mode to heat reactor, be allowed to temperature and reach 75-78 DEG C, be incubated 3-4h；
6) refilter: the insulation of question response device terminates, use vavuum pump to carry out suction filtration to the solution in reactor, then wash with distilled water；
7) roasting: the material after washing step 6) is placed in the baking oven of 40-55 DEG C and is dried to moisture less than after 5%, it is ground into end, sesbania powder and water is added to be twisted into bead, place into and the baking oven of 95-110 DEG C is dried 8-20h, separating twice the sieve crossing 80-100 mesh, take the roasting 5-8h at 500-550 DEG C of the powder between 80-100 mesh, i.e. prepare required catalyst.
As the further scheme of the present invention: the Si/Al=30-50 of described HZSM-5 type molecular sieve.
Compared with prior art, the invention has the beneficial effects as follows: the present invention uses aluminium Si catalyst catalyzing urea dehydration to prepare cyanamide, not only technique is simple, and energy consumption is low, it is little to pollute, greatly reduce the generation of accessory substance (mainly a small amount of melamine), improve the selectivity of cyanamide, application prospect is extensive.
Detailed description of the invention
Below in conjunction with the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.Based on the embodiment in the present invention, every other embodiment that those of ordinary skill in the art are obtained under the premise of not making creative work, broadly fall into the scope of protection of the invention.
In the embodiment of the present invention, a kind of technique utilizing urea to prepare cyanamide, concretely comprise the following steps:
(1) preparation of catalyst: use ion-exchange to prepare catalyst in manganese acetate solution and HZSM-5 type molecular sieve, is specifically divided into following little step:
1) the manganese acetate solution preparation of 0.2mol/L: manganese acetate four crystalline of the manganese acetate solid or 49.02g that first weigh 34.6g adds in reactor, HZSM-5 type molecular sieve (Si/Al=30-50) weighing 100g again adds in reactor, then in reactor, 1L distilled water is added so that it is mix；
2) heat: use water-bath mode that reactor is heated to 75-78 DEG C, be incubated 3-4h；
3) filter: the insulation of question response device terminates, use vavuum pump to carry out suction filtration to the solution in reactor, then wash with distilled water；
4) re-dissolved: weigh the manganese acetate solid of 34.6g or manganese acetate four crystalline of 49.02g, together joins in reactor together with the material after step 3) washing, then adds 1L distilled water in reactor so that it is mix；
5) reheat: use water-bath mode to heat reactor, be allowed to temperature and reach 75-78 DEG C, be incubated 3-4h；
6) refilter: the insulation of question response device terminates, use vavuum pump to carry out suction filtration to the solution in reactor, then wash with distilled water；
7) roasting: the material after washing step 6) is placed in the baking oven of 40-55 DEG C and is dried to moisture less than after 5%, it is ground into end, sesbania powder and water is added to be twisted into bead, place into and the baking oven of 95-110 DEG C is dried 8-20h, separating twice the sieve crossing 80-100 mesh, take the roasting 5-8h at 500-550 DEG C of the powder between 80-100 mesh, i.e. prepare required catalyst；
(2) dehydration: under ammonia atmosphere, after urea granules is heated to 500-550 DEG C, mixes with the catalyst being preheating to 500-550 DEG C and reacts；
(3) cooling, filtration: the product that step (2) obtains is cooled to 40-45 DEG C, after using dilute sulfuric acid and sodium hydrate aqueous solution to absorb the carbon dioxide in product and ammonia, the filtrate being filtrated to get is cyanamide solution；
(4) extract: after utilizing ethyl acetate to extract the cyanamide solution that step (3) obtains, filter, washing, recrystallization, it is dried to obtain cyanamide.
The present invention uses aluminium Si catalyst catalyzing urea dehydration to prepare cyanamide, and not only technique is simple, and energy consumption is low, it is little to pollute, and greatly reduces the generation of accessory substance (mainly a small amount of melamine), improves the selectivity of cyanamide, and application prospect is extensive.
It is obvious to a person skilled in the art that the invention is not restricted to the details of above-mentioned one exemplary embodiment, and without departing from the spirit or essential characteristics of the present invention, the present invention can be realized in other specific forms.Therefore, no matter from the point of view of which point, embodiment all should be regarded as exemplary, and be nonrestrictive, the scope of the present invention is limited by claims rather than described above, it is intended that include all changes falling in the implication of equivalency and scope of claim in the present invention.
In addition, should be understood, although this specification is been described by according to embodiment, but not each embodiment only comprises an independent technical scheme, this narrating mode of specification is only for clarity sake, those skilled in the art should be using specification as an entirety, and the technical scheme in each embodiment also can form, through appropriately combined, other embodiments that it will be appreciated by those skilled in the art that.
Claims (3)
1. one kind utilizes the technique that cyanamide prepared by urea, it is characterised in that concretely comprise the following steps:
(1) preparation of catalyst: use ion-exchange to prepare catalyst manganese acetate solution and HZSM-5 type molecular sieve；
(2) dehydration: under ammonia atmosphere, after urea granules is heated to 500-550 DEG C, mixes with the catalyst being preheating to 500-550 DEG C and reacts；
(3) cooling, filtration: the product that step (2) obtains is cooled to 40-45 DEG C, after using dilute sulfuric acid and sodium hydrate aqueous solution to absorb the carbon dioxide in product and ammonia, the filtrate being filtrated to get is cyanamide solution；
(4) extract: after utilizing ethyl acetate to extract the cyanamide solution that step (3) obtains, filter, washing, recrystallization, it is dried to obtain cyanamide.
2. the technique utilizing urea to prepare cyanamide according to claim 1, it is characterised in that described step (1) is divided into following little step:
1) the manganese acetate solution preparation of 0.2mol/L: manganese acetate four crystalline of the manganese acetate solid or 49.02g that first weigh 34.6g adds in reactor, the HZSM-5 type molecular sieve weighing 100g again adds in reactor, then in reactor, 1L distilled water is added so that it is mix；
2) heat: use water-bath mode that reactor is heated to 75-78 DEG C, be incubated 3-4h；
3) filter: the insulation of question response device terminates, use vavuum pump to carry out suction filtration to the solution in reactor, then wash with distilled water；
4) re-dissolved: weigh the manganese acetate solid of 34.6g or manganese acetate four crystalline of 49.02g, together joins in reactor together with the material after step 3) washing, then adds 1L distilled water in reactor so that it is mix；
5) reheat: use water-bath mode to heat reactor, be allowed to temperature and reach 75-78 DEG C, be incubated 3-4h；
6) refilter: the insulation of question response device terminates, use vavuum pump to carry out suction filtration to the solution in reactor, then wash with distilled water；
7) roasting: the material after washing step 6) is placed in the baking oven of 40-55 DEG C and is dried to moisture less than after 5%, it is ground into end, sesbania powder and water is added to be twisted into bead, place into and the baking oven of 95-110 DEG C is dried 8-20h, separating twice the sieve crossing 80-100 mesh, take the roasting 5-8h at 500-550 DEG C of the powder between 80-100 mesh, i.e. prepare required catalyst.
3. the technique utilizing urea to prepare cyanamide according to claim 2, it is characterised in that the Si/Al=30-50 of described HZSM-5 type molecular sieve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201510084237.7A CN105984888A (en) | 2015-02-16 | 2015-02-16 | Process for preparing hydrogen cyanamide by utilizing urea |
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| CN201510084237.7A CN105984888A (en) | 2015-02-16 | 2015-02-16 | Process for preparing hydrogen cyanamide by utilizing urea |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107840811A (en) * | 2017-12-15 | 2018-03-27 | 黄河三角洲京博化工研究院有限公司 | A kind of preparation method of dicyandiamide |
| CN110304638A (en) * | 2019-08-02 | 2019-10-08 | 山东益丰生化环保股份有限公司 | A method of cyanamide is prepared using urea |
| CN110775988A (en) * | 2019-11-26 | 2020-02-11 | 山东益丰生化环保股份有限公司 | Preparation method of cyanamide |
| CN113651728A (en) * | 2021-08-13 | 2021-11-16 | 四川金象赛瑞化工股份有限公司 | Method for transferring heat of polymerization reactor during dicyandiamide preparation |
-
2015
- 2015-02-16 CN CN201510084237.7A patent/CN105984888A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107840811A (en) * | 2017-12-15 | 2018-03-27 | 黄河三角洲京博化工研究院有限公司 | A kind of preparation method of dicyandiamide |
| CN110304638A (en) * | 2019-08-02 | 2019-10-08 | 山东益丰生化环保股份有限公司 | A method of cyanamide is prepared using urea |
| CN110304638B (en) * | 2019-08-02 | 2022-06-21 | 山东益丰生化环保股份有限公司 | Method for preparing cyanamide by using urea |
| CN110775988A (en) * | 2019-11-26 | 2020-02-11 | 山东益丰生化环保股份有限公司 | Preparation method of cyanamide |
| CN110775988B (en) * | 2019-11-26 | 2023-05-02 | 益丰新材料股份有限公司 | Preparation method of cyanamide |
| CN113651728A (en) * | 2021-08-13 | 2021-11-16 | 四川金象赛瑞化工股份有限公司 | Method for transferring heat of polymerization reactor during dicyandiamide preparation |
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Application publication date: 20161005 |