阅读说明：本技术 废甲醇脱氨回收系统及利用其进行废甲醇脱氨回收的方法 (Waste methanol deamination recovery system and method for performing waste methanol deamination recovery by using same ) 是由 李鹏辉 雷洁琼 褚易兴 于 2020-07-23 设计创作，主要内容包括：本发明公开的废甲醇脱氨回收系统,包括汽提塔,汽提塔的塔釜通过管道连通有第一出料冷却器,汽提塔的塔顶通过管道连通有冷凝结晶器,冷凝结晶器的底部通过管道连通至汽提塔塔顶,冷凝结晶器的顶部通过管道连通有脱氨罐,脱氨罐的底部通过管道连通有排氨塔,排氨塔的底部通过管道连通有第二出料冷却器,第二出料冷却器的另一端通过管道连通至汽提塔塔顶；本发明还公开了利用上述废甲醇脱氨回收系统进行废甲醇脱氨回收的方法。本发明的废甲醇脱氨回收系统,工艺路线简单,能耗低,运行成本低。(The invention discloses a waste methanol deamination recovery system which comprises a stripping tower, wherein a tower kettle of the stripping tower is communicated with a first discharge cooler through a pipeline, the tower top of the stripping tower is communicated with a condensation crystallizer through a pipeline, the bottom of the condensation crystallizer is communicated to the tower top of the stripping tower through a pipeline, the top of the condensation crystallizer is communicated with a deamination tank through a pipeline, the bottom of the deamination tank is communicated with an ammonia discharge tower through a pipeline, the bottom of the ammonia discharge tower is communicated with a second discharge cooler through a pipeline, and the other end of the second discharge cooler is communicated to the tower top of the stripping tower through a pipeline; the invention also discloses a method for recovering the waste methanol deamination by using the waste methanol deamination recovery system. The waste methanol deamination recovery system has the advantages of simple process route, low energy consumption and low operation cost.)

1. Waste methanol deamination recovery system, a serial communication port, including strip tower (1), the tower cauldron of strip tower (1) has first ejection of compact cooler (2) through the pipeline intercommunication, the top of the tower of strip tower (1) has condensing crystallizer (3) through the pipeline intercommunication, the bottom of condensing crystallizer (3) communicates to the top of the tower of strip tower (1) through the pipeline, there is deammoniation jar (4) at the top of condensing crystallizer (3) through the pipeline intercommunication, there is ammonia drainage tower (5) bottom of deammoniation jar (4) through the pipeline intercommunication, there is second ejection of compact cooler (6) bottom of ammonia drainage tower (5) through the pipeline intercommunication, the other end of second ejection of compact cooler (6) communicates to the top of strip tower (1) through the pipeline.

2. The waste methanol deamination recovery system as claimed in claim 1, wherein the top of the stripping tower (1) is connected with a first feed pump (7) through a pipeline, and a first discharge pump (8) is connected with a pipeline between the stripping tower (1) and the first discharge cooler (2).

3. The waste methanol deamination recovery system as claimed in claim 1, wherein a first low-pressure steam pipeline (9) is communicated with a tower kettle of the stripping tower (1), and a first temperature control valve (10) is arranged on the first low-pressure steam pipeline (9).

4. The waste methanol deamination recovery system as claimed in claim 1, wherein a reflux pump (11) is connected to a pipeline between the bottom of the condensing crystallizer (3) and the top of the stripping tower (1).

5. The waste methanol deamination recovery system according to claim 1, wherein the top of the deamination tank (4) is respectively communicated with a carbon dioxide vent gas pipeline (12), a desalted water pipeline (13) and an alcohol-containing gas pipeline (14), and a heat-taking coil (15) is arranged at the bottom in the deamination tank (4).

6. The waste methanol deamination recovery system according to claim 1, wherein a second feed pump (16) is communicated with a pipeline between the bottom of the deamination tank (4) and the ammonia discharge tower (5), and a second discharge pump (17) is communicated with a pipeline between the ammonia discharge tower (5) and the second discharge cooler (6).

7. The waste methanol deamination recovery system as claimed in claim 1, wherein a second low pressure steam pipeline (18) is connected to the bottom of the ammonia discharge tower (5), and a second temperature control valve (19) is arranged on the second low pressure steam pipeline (18).

8. The waste methanol deamination recovery system as claimed in claim 1, wherein the top of the ammonia discharge tower (5) is connected with an ammonia-containing gas pipeline (20).

9. The method for recovering the waste methanol deamination by using the waste methanol deamination recovery system of claim 1, comprising the steps of:

step 1: ammonia-containing methanol is sent to a stripping tower (1) through a first feeding pump (7), low-pressure steam is introduced into the stripping tower (1) through a first low-pressure steam pipeline (9) for stripping, the temperature of the tower bottom of the stripping tower (1) is controlled to be 76-82 ℃ through a first temperature control valve (10), and purified methanol aqueous solution is cooled to 35-45 ℃ through a first discharging cooler (2) and then is sent out through a first discharging pump (8);

step 2: the stripping gas phase at the top of the stripping tower (1) is sent to a condensing crystallizer (3) for condensation, the condensation temperature is controlled to be 35-45 ℃, and the obtained methanol aqueous solution is sent back to the top of the stripping tower (1) through a reflux pump (11);

and step 3: the noncondensable gas in the condensation crystallizer (3) is sent to a de-ammoniation tank (4), excessive carbon dioxide vent gas and de-saline water are introduced into the de-ammoniation tank (4) through a carbon dioxide vent gas pipeline (12) and a de-saline water pipeline (13), the temperature of the de-ammoniation tank (4) is controlled to be 35-45 ℃ through a heat taking coil pipe (15), and the alcohol-containing noncondensable gas on the top of the de-ammoniation tank (4) is sent to a low-temperature methanol washing device through an alcohol-containing gas pipeline (14);

and 4, step 4: the aqueous solution at the bottom of the ammonia removal tank (4) is sent to an ammonia removal tower (5) through a second feeding pump (16), low-pressure steam is introduced into the ammonia removal tower (5) through a second low-pressure steam pipeline (18), the temperature of the bottom of the ammonia removal tower (5) is controlled to be 105-112 ℃ through a second temperature control valve (19), the aqueous solution containing ammonium salt is heated and decomposed, the ammonia-containing gas at the top of the ammonia removal tower (5) is sent to a sewage stripping device through an ammonia-containing gas pipeline (20), and the aqueous solution at the bottom of the ammonia removal tower (5) is cooled to 35-45 ℃ through a second discharging cooler (6) and then is sent back to the top of the stripping tower (1) through a second discharging pump (17).

Technical Field

The invention belongs to the technical field of ammonia-containing waste methanol recovery processing technology generated by a low-temperature methanol washing technology, and particularly relates to a waste methanol deamination recovery system.

Background

The low-temperature methanol washing is a gas purification process jointly developed by Linde company and Lurgi company in Germany in the beginning of 50 years. The process takes cold methanol as an absorption solvent, and removes the acid gas in the raw material gas by utilizing the excellent characteristic that the methanol has extremely high solubility to the acid gas at low temperature. The process gas has high purification degree and good selectivity, and the desulfurization and the decarburization of the gas can be selectively carried out in a same tower in a sectional manner. Compared with other processes, the low-temperature methanol washing has the characteristics of high purification degree, low operation cost and the like, so that the low-temperature methanol washing is widely applied to gas purification devices for synthesizing ammonia, synthesizing methanol and other oxo-synthesis, city gas and the like at home and abroad. The gasified shift gas contains a trace amount of NH₃And H in low-temperature methanol absorption change gas in the system₂S、CO₂、NH₃After HCN, the poor methanol is changed into rich methanol and enters a regeneration system. Removing most of CO by flash evaporation and gas stripping₂Removal of H by thermal regeneration₂S, HCN and residual CO₂And the regeneration of the methanol is realized. However, ammonia adsorbed by methanol cannot be removed by the above means, and the ammonia content in the system must be maintained at a low level by discharging ammonia-containing methanol while supplementing fresh methanol at the time of production. When the ammonia content exceeds the standard, the ammonia content is compared with the H in the system₂S binding to form (NH)₄)₂S, increasing the regeneration difficulty, increasing the steam consumption and influencing the system operation.

Disclosure of Invention

The invention aims to provide a waste methanol deamination recovery system which is simple in process route, low in energy consumption and low in operation cost.

The invention also aims to provide a method for recovering the waste methanol deamination by using the waste methanol deamination recovery system.

The first technical scheme adopted by the invention is as follows: waste methyl alcohol deamination recovery system, including the strip tower, the tower cauldron of strip tower has first ejection of compact cooler through the pipeline intercommunication, the top of the tower of strip tower has the condensation crystallizer through the pipeline intercommunication, the bottom of condensation crystallizer communicates to the top of the strip tower through the pipeline, there is the deamination jar at the top of condensation crystallizer through the pipeline intercommunication, there is the ammonia drainage tower bottom of deamination jar through the pipeline intercommunication, there is second ejection of compact cooler bottom of ammonia drainage tower through the pipeline intercommunication, the other end of second ejection of compact cooler communicates to the top of the strip tower through the pipeline.

The first technical solution of the present invention is also characterized in that,

the top of the stripping tower is communicated with a first feeding pump through a pipeline, and a pipeline between the stripping tower and the first discharging cooler is communicated with a first discharging pump.

The tower kettle of the stripping tower is communicated with a first low-pressure steam pipeline, and a first temperature control valve is arranged on the first low-pressure steam pipeline.

A reflux pump is communicated on a pipeline between the bottom of the condensing crystallizer and the top of the stripping tower.

The top of the deamination tank is respectively communicated with a carbon dioxide emptying gas pipeline, a desalted water pipeline and an alcohol-containing gas pipeline, and the bottom in the deamination tank is provided with a heat taking coil pipe.

A second feeding pump is communicated on a pipeline between the bottom of the ammonia removal tank and the ammonia discharge tower, and a second discharging pump is communicated on a pipeline between the ammonia discharge tower and the second discharging cooler.

And a tower kettle of the ammonia discharging tower is communicated with a second low-pressure steam pipeline, and a second temperature control valve is arranged on the second low-pressure steam pipeline.

The top of the ammonia discharging tower is communicated with an ammonia-containing gas pipeline.

The second technical scheme adopted by the invention is as follows:

the method for recovering the waste methanol deamination by using the waste methanol deamination recovery system comprises the following steps:

step 1: pumping ammonia-containing methanol to a stripping tower through a first feeding pump, introducing low-pressure steam to the stripping tower through a first low-pressure steam pipeline for stripping, controlling the temperature of a tower kettle of the stripping tower to be 76-82 ℃ through a first temperature control valve, cooling a purified methanol aqueous solution to 35-45 ℃ through a first discharging cooler, and then pumping out through a first discharging pump;

step 2: feeding the steam stripping gas phase at the top of the stripping tower to a condensing crystallizer for condensation, controlling the condensation temperature to be 35-45 ℃, and feeding the obtained methanol aqueous solution back to the top of the stripping tower through a reflux pump;

and step 3: the noncondensable gas in the condensation crystallizer is sent to a deamination tank, excessive carbon dioxide vent gas and desalted water are introduced into the deamination tank through a carbon dioxide vent gas pipeline and a desalted water pipeline, the temperature of the deamination tank is controlled to be 35-45 ℃ through a heat taking coil pipe, and the alcohol-containing noncondensable gas at the top of the deamination tank is sent to a low-temperature methanol washing device through an alcohol-containing gas pipeline;

and 4, step 4: and the aqueous solution at the bottom of the ammonia removal tower is conveyed to an ammonia discharge tower through a second feeding pump, low-pressure steam is introduced into the ammonia discharge tower through a second low-pressure steam pipeline, the temperature of the tower bottom of the ammonia discharge tower is controlled at 105-112 ℃ through a second temperature control valve, the aqueous solution containing ammonium salt is heated to be decomposed, the ammonia-containing gas at the tower top of the ammonia discharge tower is conveyed to a sewage stripping device through an ammonia-containing gas pipeline, and the aqueous solution at the tower bottom of the ammonia discharge tower is cooled to 35-45 ℃ through a second discharging cooler and then is conveyed back to the tower top of the stripping tower through a second discharging.

The invention has the beneficial effects that: according to the waste methanol deamination recovery system, ammonia in the waste methanol is removed by directly stripping with low-pressure steam, so that a set of reboiler is saved, water is taken into the tower, the temperature of a medium is raised, and the removal of ammonia is facilitated. The methanol aqueous solution after ammonia removal can utilize the original methanol rectification device to recover methanol, and is simple and convenient. For the removed ammonia-containing gas, NH is generated by utilizing the vent gas of a factory low-temperature methanol washing device in a water washing state₄CO₃The ammonia is recovered. When the waste liquid is recovered, no new medium is introduced, and other waste gases are utilized.

Drawings

FIG. 1 is a schematic structural diagram of a waste methanol deamination recovery system according to the present invention.

In the figure, 1, a stripping tower, 2, a first discharge cooler, 3, a condensing crystallizer, 4, an ammonia removal tank, 5, an ammonia discharge tower, 6, a second discharge cooler, 7, a first feeding pump, 8, a first discharge pump, 9, a first low-pressure steam pipeline, 10, a first temperature control valve, 11, a reflux pump, 12, a carbon dioxide vent gas pipeline, 13, a desalting water pipeline, 14, an alcohol-containing gas pipeline, 15, a heat taking coil, 16, a second feeding pump, 17, a second discharge pump, 18, a second low-pressure steam pipeline, 19, a second temperature control valve and 20, an ammonia-containing gas pipeline.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention provides a waste methanol deamination recovery system, which comprises a stripping tower 1, wherein the top of the stripping tower 1 is communicated with a first feeding pump 7 through a pipeline, the bottom of the stripping tower 1 is communicated with a first low-pressure steam pipeline 9, a first temperature control valve 10 is arranged on the first low-pressure steam pipeline 9, the bottom of the stripping tower 1 is communicated with a first discharging cooler 2 through a pipeline, a first discharging pump 8 is communicated with a pipeline between the stripping tower 1 and the first discharging cooler 2, the top of the stripping tower 1 is communicated with a condensing crystallizer 3 through a pipeline, the bottom of the condensing crystallizer 3 is communicated with the top of the stripping tower 1 through a pipeline, a reflux pump 11 is communicated with a pipeline between the bottom of the condensing crystallizer 3 and the top of the stripping tower 1, the top of the condensing crystallizer 3 is communicated with a deamination tank 4 through a pipeline, and the top of the deamination tank 4 is respectively communicated with a carbon dioxide vent gas pipeline 12, Desalting water pipeline 13 and alcohol-containing gas pipeline 14, the bottom is provided with gets hot coil pipe 15 in the deammoniation jar 4, the bottom of deammoniation jar 4 has ammonia extraction tower 5 through the pipeline intercommunication, the intercommunication has second charge pump 16 on the pipeline between the bottom of deammoniation jar 4 and the ammonia extraction tower 5, the top of the tower intercommunication of ammonia extraction tower 5 has ammonia-containing gas pipeline 20, the tower cauldron intercommunication of ammonia extraction tower 5 has second low pressure steam pipe 18, be provided with second temperature control valve 19 on the second low pressure steam pipe 18, the bottom of ammonia extraction tower 5 has second ejection of compact cooler 6 through the pipeline intercommunication, the intercommunication has second ejection of compact pump 17 on the pipeline between ammonia extraction tower 5 and second ejection of compact cooler 6, the other end of second ejection of compact cooler 6 communicates to the top of stripping tower 1 through the pipeline.

The invention also provides a method for recovering the waste methanol deamination by using the waste methanol deamination recovery system, which comprises the following steps:

step 1: ammonia-containing methanol is sent to a stripping tower 1 through a first feeding pump 7, low-pressure steam is fed into the stripping tower 1 through a first low-pressure steam pipeline 9 for stripping, the temperature of a tower kettle of the stripping tower 1 is controlled to be 76-82 ℃ through a first temperature control valve 10, and purified methanol aqueous solution is cooled to 35-45 ℃ through a first discharging cooler 2 and then is sent out through a first discharging pump 8;

step 2: feeding the steam stripping gas phase at the top of the steam stripping tower 1 to a condensing crystallizer 3 for condensation, controlling the condensation temperature to be 35-45 ℃, and feeding the obtained methanol aqueous solution back to the top of the steam stripping tower 1 through a reflux pump 11;

and step 3: the noncondensable gas in the condensation crystallizer 3 is sent to a deamination tank 4, excessive carbon dioxide vent gas and desalted water are introduced into the deamination tank 4 through a carbon dioxide vent gas pipeline 12 and a desalted water pipeline 13, the temperature of the deamination tank 4 is controlled to be 35-45 ℃ through a heat-taking coil 15, and the alcohol-containing noncondensable gas at the top of the deamination tank 4 is sent to a low-temperature methanol washing device through an alcohol-containing gas pipeline 14;

and 4, step 4: the aqueous solution at the bottom of the ammonia removal tank 4 is sent to an ammonia discharge tower 5 through a second feeding pump 16, low-pressure steam is introduced into the ammonia discharge tower 5 through a second low-pressure steam pipeline 18, the temperature of the bottom of the ammonia discharge tower 5 is controlled at 105-112 ℃ through a second temperature control valve 19, the aqueous solution containing ammonium salt is heated and decomposed, the ammonia-containing gas at the top of the ammonia discharge tower 5 is sent to a sewage stripping device through an ammonia-containing gas pipeline 20, and the aqueous solution at the bottom of the ammonia discharge tower 5 is cooled to 35-45 ℃ through a second discharge cooler 6 and then sent back to the top of the stripping tower 1 through a second discharge pump 17.

Through the mode, according to the waste methanol deamination recovery system, ammonia in the waste methanol is removed through direct steam stripping of low-pressure steam, a set of reboiler is saved, water is also taken into the tower, the temperature level of a medium is increased, and ammonia removal is facilitated. The methanol aqueous solution after ammonia removal can utilize the original methanol rectification device to recover methanol, and is simple and convenient. For the removed ammonia-containing gas, NH is generated by utilizing the vent gas of a factory low-temperature methanol washing device in a water washing state₄CO₃The ammonia is recovered. When the waste liquid is recovered, no new medium is introduced, and other waste gases are utilized.