CN112678847B - Urea coupling hydrolyzer and urea coupling hydrolysis method thereof - Google Patents
Urea coupling hydrolyzer and urea coupling hydrolysis method thereof Download PDFInfo
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- CN112678847B CN112678847B CN202011630140.9A CN202011630140A CN112678847B CN 112678847 B CN112678847 B CN 112678847B CN 202011630140 A CN202011630140 A CN 202011630140A CN 112678847 B CN112678847 B CN 112678847B
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
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Abstract
The invention relates to a urea coupling hydrolyzer, comprising: the urea coupling hydrolyzer comprises a heat exchanger tube bundle horizontally arranged at the inner bottom end of a urea coupling hydrolyzer main body, an outlet pipeline vertically arranged at the tail of the urea coupling hydrolyzer main body, a product outlet arranged at the top end of the outlet pipeline, a gas-liquid separator arranged in the outlet pipeline, a gas-liquid separation tube vertically arranged at the lower side of the gas-liquid separator, a coupling catalyst horizontally arranged at the upper side of the gas-liquid separator and a urea solution/desalted water inlet arranged on the upper side of the middle part of the side wall of the urea coupling hydrolyzer main body. According to the urea coupling hydrolyzer, on the premise of not increasing pressure and temperature, the gas-liquid separator and the coupling catalyst are additionally arranged at the gas outlet position of the product to improve the conversion rate and conversion efficiency of ammonia production from urea, intermediate products are reduced, energy is saved, and meanwhile, the operation cost is reduced for vast users.
Description
Technical Field
The invention relates to the technical field of ammonia production by SCR denitration urea, in particular to a urea coupling hydrolyzer and a urea coupling hydrolysis method thereof.
Background
The reducing agent for SCR flue gas denitration generally comprises three types of liquid ammonia, ammonia water and urea. Since liquid ammonia is a hazardous chemical, there are many severe restrictions on its transportation, storage and use. In addition, in recent years, the frequent occurrence of ammonia explosion or leakage accidents is caused, important hazard sources in the liquid ammonia tank areas are required to be treated, and the progress of urea replacement, upgrading and reconstruction is promoted.
The urea replacement upgrading and reforming technology mainly comprises two types, namely urea pyrolysis and urea hydrolysis, wherein the urea hydrolysis technology is limited by technology, pressure and temperature, intermediate products are easy to corrode and block subsequent equipment when urea is used for preparing ammonia, and the conversion efficiency is relatively low.
Accordingly, a new process is needed to solve the above problems.
Disclosure of Invention
The invention aims at overcoming the defects in the prior art and provides a urea coupling hydrolyzer and a urea coupling hydrolysis method thereof.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a first aspect of the invention provides a urea coupling hydrolyzer comprising: the urea coupling hydrolyzer comprises a heat exchanger tube bundle horizontally arranged at the inner bottom end of a urea coupling hydrolyzer main body, an outlet pipeline vertically arranged at the tail of the urea coupling hydrolyzer main body, a product outlet arranged at the top end of the outlet pipeline, a gas-liquid separator arranged in the outlet pipeline, a gas-liquid separation tube vertically arranged at the lower side of the gas-liquid separator, a coupling catalyst horizontally arranged at the upper side of the gas-liquid separator and a urea solution/desalted water inlet arranged on the upper side of the middle part of the side wall of the urea coupling hydrolyzer main body;
the head of the heat exchanger tube bundle extends out of the urea coupling hydrolyzer main body, and the extending section and the urea coupling hydrolyzer main body are sealed; the upper side of the head part of the heat exchanger tube bundle is provided with a steam inlet, and the lower side of the head part of the heat exchanger tube bundle is provided with a steam outlet; the lower end of the gas-liquid separation pipe is inserted below the liquid level, the middle of the gas-liquid separation pipe is horizontally provided with a tangential inlet for gas to enter, and the upper end of the gas-liquid separation pipe is connected with the gas-liquid separator through a flange; the coupling catalyst is fixed on the upper side of the gas-liquid separator through a grid.
Preferably, the method further comprises: manhole, several blow-down holes, several liquid level measuring holes and several temperature measuring holes;
the manhole and the liquid level measuring hole are formed in the top end of the urea coupling hydrolyzer main body; the sewage draining hole is arranged at the middle part or/and the bottom end of the side wall of the urea coupling hydrolyzer main body; the temperature measuring hole is formed in the middle of the side wall of the urea coupling hydrolyzer main body and is downward.
Preferably, the steam inlet is also provided with an inlet steam regulating valve.
Preferably, the heat exchanger tube bundle is made of 316L stainless steel with a tube bundle diameter of 18-32 mm.
Preferably, the urea coupling hydrolyzer body is a horizontal pressure vessel.
Preferably, the gas-liquid separator is an S-shaped blade made of 316L stainless steel, and the blade spacing is 10-40 mm.
Preferably, the coupling catalyst is in a solid spherical shape or a honeycomb shape, and comprises the following components in percentage by mass:
TiO 2 70～90％；
Al 2 O 3 v (V) 2 O 5 10～30％。
The pipe diameter of the steam inlet can be calculated and determined according to the amount of the hydrolysate; the diameter of the urea coupling hydrolyzer main body can be calculated and determined according to the ammonia amount; the pipe diameter of the urea solution/desalted water inlet can be calculated and determined according to the amount of the hydrolysis product.
In a second aspect, the present invention provides a urea coupling hydrolysis method using a urea coupling hydrolyzer as described above, comprising the steps of:
s1, adding desalted water into the urea coupling hydrolyzer main body through the urea solution/desalted water inlet, and at least reaching 25% of the volume of the urea coupling hydrolyzer main body;
s2, dissolving dry urea into urea solution with the mass concentration of 50%, and adding the urea solution into the urea coupling hydrolyzer main body through the urea solution/desalted water inlet, wherein the urea coupling hydrolyzer main body is at least 25% of the urea coupling hydrolyzer main body; adding desalted water and urea solution into the urea coupling hydrolyzer main body in a time-sharing manner;
s3, introducing steam into the heat exchanger tube bundle through the steam inlet for heating, wherein the inlet steam regulating valve controls the heating temperature to be 140-190 ℃ and the pressure to be 0.35-0.39MPa so as to realize urea decomposition;
s4, sequentially passing the product gas through the gas-liquid separation tube, the gas-liquid separator and the coupling catalyst to completely remove liquid components therein and catalyze intermediate products therein to generate NH 3 ；
S5, the ammonia-containing mixed gas obtained in the step S4 after complete dewatering and conversion enters a conveying pipeline from the product outlet to be supplied to a subsequent denitration device.
Compared with the prior art, the invention has the following technical effects:
1) The gas-liquid separation pipe and the gas-liquid separator which are added at the product outlet can reduce the water content in the product gas by 99 percent, thereby greatly reducing the corrosiveness of the product gas and the corrosion accidents of Du Juehou continuous valve instruments and the like;
2) The coupling catalyst specially arranged at the product outlet can catalyze byproducts HNCO, cyanuric acid, biuret, ammonium carbamate and the like in the product gas into NH 3 Thereby greatly reducing the faults of corrosion, blockage and the like of subsequent equipment;
3) The reaction conversion rate is improved, and the operation cost is reduced.
In summary, the urea coupling hydrolyzer provided by the invention has higher superiority.
Drawings
FIG. 1 is a schematic diagram of a urea coupling hydrolyzer according to the invention;
wherein, the reference numerals include: a steam inlet 1, a steam outlet 2, a heat exchanger tube bundle 3, a urea coupling hydrolyzer main body 4, a product outlet 5, a gas-liquid separator 6, a gas-liquid separation tube 7, a coupling catalyst 8, a urea solution/desalted water inlet 9, a manhole 10, a sewage draining hole 11, a liquid level measuring hole 12 and a temperature measuring hole 13.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.
The invention is further described below with reference to the drawings and specific examples, which are not intended to be limiting.
Example 1
As shown in fig. 1, this embodiment provides a urea coupling hydrolyzer, including: the urea coupling hydrolyzer comprises a heat exchanger tube bundle 3 horizontally arranged at the inner bottom end of a urea coupling hydrolyzer main body 4, an outlet pipeline vertically arranged at the tail of the urea coupling hydrolyzer main body 4, a product outlet 5 arranged at the top end of the outlet pipeline, a gas-liquid separator 6 arranged in the outlet pipeline, a gas-liquid separation tube 7 vertically arranged at the lower side of the gas-liquid separator 6, a coupling catalyst 8 horizontally arranged at the upper side of the gas-liquid separator 6 and a urea solution/desalted water inlet 9 arranged at the upper side of the middle part of the side wall of the urea coupling hydrolyzer main body 4;
the head of the heat exchanger tube bundle 3 extends out of the urea coupling hydrolyzer main body 4, and the extending section is sealed with the urea coupling hydrolyzer main body 4; the upper side of the head of the heat exchanger tube bundle 3 is provided with a steam inlet 1, and the lower side is provided with a steam outlet 2; the lower end of the gas-liquid separation pipe 7 is inserted below the liquid level, the middle is horizontally provided with a tangential inlet for gas to enter, and the upper end of the gas-liquid separation pipe is connected with the gas-liquid separator 6 through a flange; the coupling catalyst 8 is fixed to the upper side of the gas-liquid separator 6 through a grid.
Preferably, the method further comprises: manhole 10, several blow-down holes 11, several liquid level measuring holes 12 and several temperature measuring holes 13;
wherein the manhole 10 and the liquid level measuring hole 12 are arranged at the top end of the urea coupling hydrolyzer main body 4; the sewage draining hole 11 is arranged at the middle part or/and the bottom end of the side wall of the urea coupling hydrolyzer main body 4; the temperature measuring hole is formed in the middle of the side wall of the urea coupling hydrolyzer main body 4.
Preferably, an inlet steam regulating valve is further arranged at the steam inlet 1.
Preferably, the heat exchanger tube bundle 3 is made of 316L stainless steel with a tube bundle diameter of 18-32 mm.
Preferably, the urea coupling hydrolyzer body 4 is a horizontal pressure vessel.
Preferably, the gas-liquid separator 6 is an S-shaped blade made of 316L stainless steel, and the blade pitch is 10-40 mm.
Preferably, the coupling catalyst 8 is in a solid spherical or honeycomb shape, and comprises the following components in percentage by mass:
TiO 2 70～90％；
Al 2 O 3 v (V) 2 O 5 10～30％。
Example 2
This example provides a urea coupling hydrolysis process using the urea coupling hydrolyzer of example 1, comprising the steps of:
s1, adding desalted water into the urea coupling hydrolyzer main body 4 through the urea solution/desalted water inlet 9, and at least reaching 25% of the volume of the urea coupling hydrolyzer main body 4;
s2, dissolving dry urea into urea solution with the mass concentration of 50%, and adding the urea solution into the urea coupling hydrolyzer main body 4 through the urea solution/desalted water inlet 9, wherein the urea coupling hydrolyzer main body 4 is at least 25% of the volume of the urea coupling hydrolyzer main body 4;
s3, introducing steam into the heat exchanger tube bundle 3 through the steam inlet 1 for heating, and controlling the heating temperature to be 140-190 ℃ and the pressure to be 0.35-0.39MPa by the inlet steam regulating valve so as to realize urea decomposition;
s4, sequentially passing the product gas through the gas-liquid separation pipe 7, the gas-liquid separator 6 and the coupling catalyst 8 to completely remove liquid components therein and catalyze intermediate products therein to generate NH 3 ；
S5, the ammonia-containing mixed gas obtained in the step S4 after complete dewatering and conversion enters a conveying pipeline from the product outlet 5 to be supplied to a subsequent denitration device.
According to the urea coupling hydrolyzer, on the premise of not increasing pressure and temperature, the gas-liquid separator and the coupling catalyst are additionally arranged at the gas outlet position of the product to improve the conversion rate and conversion efficiency of ammonia production from urea, intermediate products are reduced, energy is saved, and meanwhile, the operation cost is reduced for vast users.
The foregoing description is only illustrative of the preferred embodiments of the present invention and is not to be construed as limiting the scope of the invention, and it will be appreciated by those skilled in the art that equivalent substitutions and obvious variations may be made using the description and illustrations of the present invention, and are intended to be included within the scope of the present invention.
Claims (6)
1. A urea-coupled hydrolyzer, comprising: the urea coupling hydrolyzer comprises a heat exchanger tube bundle (3) horizontally arranged at the inner bottom end of a urea coupling hydrolyzer main body (4), an outlet pipeline vertically arranged at the tail of the urea coupling hydrolyzer main body (4), a product outlet (5) arranged at the top end of the outlet pipeline, a gas-liquid separator (6) arranged in the outlet pipeline, a gas-liquid separation tube (7) vertically arranged at the lower side of the gas-liquid separator (6), a coupling catalyst (8) horizontally arranged at the upper side of the gas-liquid separator (6) and a urea solution/desalted water inlet (9) arranged on the middle part of the side wall of the urea coupling hydrolyzer main body (4);
the head of the heat exchanger tube bundle (3) extends out of the urea coupling hydrolyzer main body (4), and the extending section is sealed with the urea coupling hydrolyzer main body (4); the upper side of the head of the heat exchanger tube bundle (3) is provided with a steam inlet (1), and the lower side is provided with a steam outlet (2); the lower end of the gas-liquid separation pipe (7) is inserted below the liquid level, the middle is horizontally provided with a tangential inlet for gas to enter, and the upper end of the gas-liquid separation pipe is connected with the gas-liquid separator (6) through a flange; the coupling catalyst (8) is fixed on the upper side of the gas-liquid separator (6) through a grid;
the coupling catalyst (8) is solid spherical or honeycomb, and comprises the following components in percentage by mass:
TiO 2 70～90％；
Al 2 O 3 v (V) 2 O 5 10～30％；
Further comprises: a manhole (10), a plurality of blow-down holes (11), a plurality of liquid level measuring holes (12) and a plurality of temperature measuring holes (13);
wherein the manhole (10) and the liquid level measuring hole (12) are arranged at the top end of the urea coupling hydrolyzer main body (4); the sewage draining hole (11) is arranged at the middle part or/and the bottom end of the side wall of the urea coupling hydrolyzer main body (4); the temperature measuring hole is formed in the middle of the side wall of the urea coupling hydrolyzer main body (4) and is downward.
2. Urea coupling hydrolyzer according to claim 1, in which the steam inlet (1) is also provided with an inlet steam regulating valve.
3. Urea coupling hydrolyzer according to claim 1, in which the heat exchanger tube bundle (3) is made of 316L stainless steel with a tube bundle diameter of 18-32 mm.
4. Urea coupling hydrolyzer according to claim 1, in which the urea coupling hydrolyzer body (4) is a horizontal pressure vessel.
5. Urea coupling hydrolyzer according to claim 1, in which the gas-liquid separator (6) is S-shaped blades made of 316L stainless steel with a blade pitch of 10-40 mm.
6. A urea coupling hydrolysis process employing a urea coupling hydrolyzer according to any of claims 1-5, comprising the steps of:
s1, adding desalted water into the urea coupling hydrolyzer main body (4) through the urea solution/desalted water inlet (9) and at least reaching 25% of the volume of the urea coupling hydrolyzer main body (4);
s2, dissolving dry urea into a urea solution with the mass concentration of 50%, and adding the urea solution into the urea coupling hydrolyzer main body (4) through the urea solution/desalted water inlet (9), wherein the urea coupling hydrolyzer main body (4) is at least 25% of the volume of the urea coupling hydrolyzer main body (4);
s3, introducing steam into the heat exchanger tube bundle (3) through the steam inlet (1) for heating, and controlling the heating temperature to be 140-190 ℃ and the pressure to be 0.35-0.39MPa by the inlet steam regulating valve so as to realize urea decomposition;
s4, sequentially passing the product gas through the gas-liquid separation pipe (7), the gas-liquid separator (6) and the coupling catalyst (8) to completely remove liquid components and catalyze intermediate products therein into NH 3 ；
S5, the ammonia-containing mixed gas obtained in the step S4 after complete dewatering and conversion enters a conveying pipeline from the product outlet (5) to be supplied to a subsequent denitration device.
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| CN114505044B (en) * | 2022-02-23 | 2023-10-20 | 西安热工研究院有限公司 | Filling urea catalytic hydrolysis system and method |
| CN115430391A (en) * | 2022-10-13 | 2022-12-06 | 江苏峰业环境科技集团股份有限公司 | Urea catalytic hydrolysis reactor with shock mounting |
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| GB0709137D0 (en) * | 2007-05-11 | 2007-06-20 | Norgren Ltd C A | Method and apparatus for controlling gaseous hydrolysis production |
| CN202430017U (en) * | 2012-02-02 | 2012-09-12 | 成都融科能源环境工程有限公司 | Urea hydrolyzer applied to flue gas denitrification |
| CN203922753U (en) * | 2014-06-06 | 2014-11-05 | 四川晨光工程设计院 | A kind of urea hydrolyser for the production of ammonia |
| CN204583109U (en) * | 2014-12-22 | 2015-08-26 | 上海洁昊环保股份有限公司 | For the high accuracy urea liquid dilution metering system of SNCR denitration system |
| CN204827613U (en) * | 2015-07-13 | 2015-12-02 | 大连大学 | Automobile -used SCR urea hydrolysis reactor |
| CN209554803U (en) * | 2018-12-19 | 2019-10-29 | 江苏中立环保科技有限公司 | Urea seeding hydrolysis device |
| CN210278545U (en) * | 2019-07-09 | 2020-04-10 | 希柯中立工业技术江阴有限公司 | Anti-blocking gas collector for urea catalytic hydrolysis |
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