Integrated system for coal gas water pretreatment and phenol ammonia recycling

Abstract

The utility model relates to coal gas water pretreatment technical field, concretely relates to a kind of coal gas water pretreatment and phenol ammonia recycling integrated system, the system includes deacidification tower, for the deacidification treatment of coal gas water;Acid gas treatment equipment, for the treatment of acid gas from deacidification tower;Deamination tower, for the deamination treatment of coal gas water after deacidification treatment by deacidification tower;Ammonia gas liquid separation equipment and ammonia recovery treatment equipment, for recycling ammonia;Extraction tower, for the dephenol treatment of coal gas water after deamination treatment by deamination tower;Phenol recovery tower and crude phenol purification equipment, for separating phenol and extractant in extractant from extraction tower, and extractant is sent back to the extractant tank, crude phenol purification;Water tower, for sending into subsequent biochemical treatment after separating extractant in coal gas water after dephenol, and the separated extractant is sent back to extractant tank. Using the system, the acid gas, ammonia and phenol in coal gas water can be effectively removed, and phenol ammonia recycling is realized.

Description

Technical Field

[0001] This utility model relates to the field of coal gas and water pretreatment technology, specifically to an integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization. Background Technology

[0002] After the coal gasification section's coal gas water undergoes tar and oil separation in the coal gas water separation section, it still contains many phenolic substances and other impurities, mainly ammonia, carbon dioxide, monophenols, polyphenols, fatty acids, and oils. These substances are all polar; ammonia, carbon dioxide, and hydrogen sulfide are volatile weak electrolytes in aqueous solutions. Acidic gases such as H2S and CO2 in the phenolic water can interfere with the treatment process and cause equipment corrosion and scaling. Furthermore, ammonia and phenols inhibit microorganisms, affecting subsequent biological treatment. Therefore, it is necessary to remove most of the contaminants from the phenolic water to reduce the load on the subsequent biological treatment section. However, existing coal gas water pretreatment devices cannot effectively remove impurities from the coal gas water, especially acidic gases, ammonia, and phenols.

[0003] Therefore, there is an urgent need for an integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization, so as to effectively remove acidic gases, ammonia and phenol from coal gas and water and realize the recovery and utilization of phenol and ammonia. Utility Model Content

[0004] The purpose of this invention is to solve the problem that existing gas-water pretreatment devices cannot effectively remove acidic gases, ammonia, and phenols from gas-water. This invention provides an integrated system for gas-water pretreatment and phenol / ammonia recovery and utilization, which can effectively remove acidic gases, ammonia, and phenols from gas-water and realize the recovery and utilization of phenols and ammonia.

[0005] To achieve the above objectives, this utility model provides an integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization, the integrated system comprising:

[0006] The deacidification tower has a cold material inlet at the top, through which one stream of coal gas and water is cooled and then introduced into the cold material inlet. A preheating material inlet is located in the middle and upper part, through which another stream of coal gas and water is preheated and then introduced into the preheating material inlet, for the purpose of deacidification treatment of coal gas and water.

[0007] An acid gas treatment device for treating acid gases from the top of the deacidification tower;

[0008] Ammonia removal tower, wherein one material inlet at the top is connected to the bottom of the acid removal tower, and another material inlet is connected to the alkali tank, is used to remove ammonia from the coal gas water after acid removal treatment by the acid removal tower;

[0009] An ammonia gas-liquid separation device is used to separate the ammonia gas-liquid mixture from the top of the ammonia removal tower to obtain crude ammonia gas.

[0010] An ammonia recovery and processing device is used to recover crude ammonia gas from the ammonia gas-liquid separation device into liquid ammonia.

[0011] An extraction tower, wherein the upper part is connected to the bottom of the deammoniation tower and the bottom is connected to the extractant tank, is used to perform phenol removal treatment on the coal gas water after deammoniation treatment by the deammoniation tower;

[0012] A phenol recovery tower, wherein the upper part is connected to the top of the extraction tower, for separating phenol and extractant from the extract from the extraction tower, and returning the extractant at the top to the extractant tank;

[0013] A crude phenol purification device, wherein the upper part is connected to the bottom of the phenol recovery tower, and is used to purify the crude phenol from the phenol recovery tower;

[0014] A water tower, the upper part of which is connected to the bottom of the extraction tower, is used to separate the extractant from the coal gas water after the phenol removal treatment in the extraction tower and send it to subsequent biochemical treatment, and to return the separated extractant to the extractant tank.

[0015] Preferably, a cooler is provided upstream of the cold material inlet of the deacidification tower to cool the coal gas water to a set cooling temperature; a preheater is provided upstream of the preheating material inlet of the deacidification tower to preheat the coal gas water to a set preheating temperature.

[0016] Preferably, the preheater includes a primary heat exchanger, a secondary heat exchanger, and a tertiary heat exchanger connected in series with their heat exchange temperatures increasing sequentially.

[0017] Preferably, the acid gas treatment equipment includes a condenser for separating the liquid phase from the acid gas and sending it to a boiler for incineration.

[0018] Preferably, the ammonia gas-liquid separation equipment includes a primary condenser, a secondary condenser, and a tertiary condenser connected in series. The primary condenser, the secondary condenser, and the tertiary condenser sequentially cool and separate the ammonia gas-liquid mixture to obtain crude ammonia gas.

[0019] Preferably, it further includes an ammonia recovery and treatment device, the ammonia recovery and treatment device comprising:

[0020] Ammonia purification tower is used to purify incoming crude ammonia gas by washing it with dilute ammonia water.

[0021] An ammonia absorber is used to absorb ammonia gas purified by the ammonia purification tower into dilute ammonia water.

[0022] An ammonia distillation heat exchanger is used to treat the dilute ammonia water from the ammonia absorber.

[0023] The ammonia distillation column is used to distill the dilute ammonia water after heat exchange treatment by the ammonia distillation heat exchanger to obtain purified ammonia gas.

[0024] An ammonia distillation cooler is used to condense purified ammonia gas into liquid ammonia for use.

[0025] Preferably, the ammonia recovery and treatment equipment further includes an oil removal filter for removing oil from the crude ammonia gas before it is introduced into the ammonia purification tower;

[0026] The ammonia purification tower also includes a circulation pump, which is used to circulate and wash the crude ammonia gas with dilute ammonia water in the ammonia purification tower.

[0027] Preferably, the crude phenol purification equipment includes:

[0028] A crude phenol purification tower is used to purify crude phenol from the phenol recovery tower.

[0029] A phenol vapor condenser is used to condense the crude phenol vapor output from the top of the crude phenol purification tower;

[0030] Phenol storage tanks are used to store phenol products that have condensed into a liquid phase.

[0031] Preferably, a first heat exchanger is provided on the connecting pipeline between the bottom of the deammoniation tower and the upper middle part of the extraction tower, for exchanging heat between the coal gas and water after deammoniation treatment by the deammoniation tower and the first set temperature.

[0032] Preferably, a second heat exchanger is provided on the connecting pipeline between the top of the extraction tower and the upper middle part of the phenol recovery tower for exchanging heat to the extract to a second set temperature.

[0033] Preferably, a third heat exchanger is provided on the connecting pipe between the bottom of the extraction tower and the upper middle part of the water tower, for exchanging heat between the coal gas and water after phenol removal treatment by the extraction tower and the third set temperature.

[0034] Preferably, the extractant in the extractant tank is any one of benzene, heavy benzene, light oil, heavy solvent oil, isopropyl ether, tributyl phosphate, and methyl isobutyl ketone.

[0035] The advantages of this invention compared to existing technologies are as follows: by setting up a deacidification tower, acidic gases in the coal gas water can be effectively removed; by setting up an ammonia removal tower, ammonia in the coal gas water can be effectively removed; by setting up an extraction tower, phenol in the coal gas water can be effectively removed, thereby effectively removing acidic gases, ammonia, and phenol from the coal gas water; by setting up ammonia gas-liquid separation equipment, ammonia recovery and treatment equipment, and crude phenol purification equipment, phenol and ammonia can be recovered and reused; and by setting up a phenol recovery tower and a water tower, the extractant can be recovered and recycled. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of an integrated system for gas and water pretreatment and phenol and ammonia recovery and utilization.

[0037] Figure 2 This is a schematic diagram of the ammonia recovery treatment equipment in an integrated system of coal gas and water pretreatment and phenol and ammonia recovery and utilization.

[0038] Figure 3 This is a schematic diagram of the crude phenol purification equipment in an integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization.

[0039] Explanation of reference numerals in the attached figures

[0040] 1. Deacidification tower; 2. Deammoniation tower; 3. Extraction tower; 4. Water tower; 5. Phenol recovery tower; 6. Cooler; 7. Primary heat exchanger; 8. Secondary heat exchanger; 9. Tertiary heat exchanger; 10. Alkali tank; 11. Primary condenser; 12. Secondary condenser; 13. Tertiary condenser; 14. Condenser; 15. Extractant tank; 16. Ammonia purification tower; 17. Ammonia distillation tower; 18. Ammonia absorber; 19. Ammonia distillation heat exchanger; 20. Ammonia distillation cooler; 21. Crude phenol purification tower; 22. Phenol vapor condenser; 23. Phenol storage tank. Detailed Implementation

[0041] The following provides a detailed description of the specific embodiments of this utility model. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of this utility model.

[0042] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The term "comprising" and any variations thereof mean a non-exclusive inclusion, the possibility of the presence or addition of one or more other features, units, components, and / or combinations thereof.

[0043] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] This utility model provides an integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization, such as Figure 1 As shown, the integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization includes:

[0045] The deacidification tower 1 has a cold material inlet at the top, through which one stream of coal gas and water is cooled and then introduced into the cold material inlet. The upper middle part has a preheating material inlet, through which another stream of coal gas and water is preheated and then introduced into the preheating material inlet, for the purpose of deacidification treatment of coal gas and water.

[0046] An acid gas treatment device for treating acid gas from the top of the deacidification tower 1;

[0047] Ammonia removal tower 2, wherein one material inlet at the top is connected to the bottom of the acid removal tower 1, and the other material inlet is connected to the alkali tank 10, is used to remove ammonia from the coal gas water after acid removal treatment by the acid removal tower 1;

[0048] An ammonia gas-liquid separation device is used to separate the ammonia gas-liquid mixture from the top of the ammonia removal tower 2 to obtain crude ammonia gas.

[0049] An ammonia recovery and processing device is used to recover crude ammonia gas from the ammonia gas-liquid separation device into liquid ammonia.

[0050] Extraction tower 3, the upper part of which is connected to the bottom of the deammoniation tower 2 and the bottom of which is connected to the extractant tank 15, is used to remove phenol from the coal gas water after it has been deammonised by the deammoniation tower 2;

[0051] The phenol recovery tower 5, whose upper part is connected to the top of the extraction tower 3, is used to separate phenol and extractant from the extract from the extraction tower 3 and to return the extractant at the top to the extractant tank 15.

[0052] A crude phenol purification device, wherein the upper part is connected to the bottom of the phenol recovery tower 5, and is used to purify the crude phenol from the phenol recovery tower 5.

[0053] Water tower 4, the upper part of which is connected to the bottom of the extraction tower 3, is used to separate the extractant from the coal gas water after the phenol removal treatment of the extraction tower 3 and send it to the subsequent biochemical treatment, and to return the separated extractant to the extractant tank 15.

[0054] According to the above technical solution, based on this integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization, acidic gases, ammonia and phenols in coal gas and water can be effectively removed in practical applications, thereby meeting the needs of the next step of biochemical treatment and realizing the recovery and utilization of phenol and ammonia.

[0055] In the integrated system for coal gas-water pretreatment and phenol-ammonia recovery and utilization described in this utility model, preferably, a cooler 6 is installed upstream of the cold feed inlet of the deacidification tower 1 to cool the coal gas-water to a set cooling temperature; a preheater is installed upstream of the preheating feed inlet of the deacidification tower 1 to preheat the coal gas-water to a set preheating temperature. Specifically, the set cooling temperature is 30-40℃, and the set preheating temperature is 130-135℃. By cooling the coal gas-water entering the cold feed inlet to 30-40℃ and preheating the coal gas-water entering the preheating feed inlet to 130-135℃, the deacidification tower 1 can effectively remove acidic gases from the coal gas-water in practical applications.

[0056] More preferably, the preheater includes a primary heat exchanger 7, a secondary heat exchanger 8, and a tertiary heat exchanger 9 connected in series with their heat exchange temperatures increasing sequentially, thereby better preheating the gas and water to the set preheating temperature based on gradient heat exchange.

[0057] In the integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization described in this utility model, preferably, a first heat exchanger is provided on the connecting pipeline between the bottom of the deammoniation tower 2 and the upper middle part of the extraction tower 3, which is used to exchange heat with the coal gas and water after deammoniation treatment by the deammoniation tower 2 to a first set temperature, specifically the first set temperature is 40-65℃, thereby improving the extraction effect.

[0058] In another preferred embodiment, a second heat exchanger is provided on the connecting pipeline between the top of the extraction tower 3 and the upper middle part of the phenol recovery tower 5, for exchanging heat to the extract to a second set temperature, specifically 95-105℃, thereby improving the separation effect of phenol and extractant in the extract.

[0059] In another preferred embodiment, a third heat exchanger is provided on the connecting pipe between the bottom of the extraction tower 3 and the upper middle part of the water tower 4, for exchanging heat between the coal gas and water after phenol removal treatment by the extraction tower 3 and a third set temperature, specifically the third set temperature is 70-80℃, thereby improving the separation effect of the extractant.

[0060] In another preferred embodiment, the extractant in the extractant tank 15 is any one of benzene, heavy benzene, light oil, heavy solvent oil, isopropyl ether, tributyl phosphate and methyl isobutyl ketone, preferably methyl isobutyl ketone.

[0061] In another preferred embodiment, the alkaline solution in the alkaline solution tank 10 is a NaOH solution.

[0062] In the integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization described in this utility model, preferably, the acid gas treatment equipment includes a condenser 14, which is used to separate the liquid phase in the acid gas and send it to the boiler for incineration, thereby fundamentally and effectively removing the acid gas in the coal gas and water.

[0063] In the integrated system for coal gas-water pretreatment and phenol-ammonia recovery and utilization described in this utility model, preferably, the ammonia gas-liquid separation equipment includes a primary condenser 11, a secondary condenser 12, and a tertiary condenser 13 connected in series. The primary condenser 11, the secondary condenser 12, and the tertiary condenser 13 sequentially cool and separate the ammonia gas-liquid mixture to obtain crude ammonia gas, thereby completely separating crude ammonia gas from the ammonia gas-liquid mixture. Preferably, the heat exchange temperature of the primary condenser 11 is 118-124℃ and the pressure is 0.28-0.30 MPa; the heat exchange temperature of the secondary condenser 12 is 85-95℃ and the pressure is 0.26-0.30 MPa; and the heat exchange temperature of the tertiary condenser 13 is 40-45℃ and the pressure is 0.24-0.26 MPa.

[0064] Further preferred, such as Figure 2 As shown, the integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization also includes an ammonia recovery and treatment device, which includes:

[0065] Ammonia purification tower 16 is used to purify incoming crude ammonia gas by washing it with dilute ammonia water.

[0066] Ammonia absorber 18 is used to absorb ammonia gas purified by the ammonia purification tower 16 into dilute ammonia water.

[0067] Ammonia distillation heat exchanger 19 is used to perform heat exchange treatment on dilute ammonia water from the ammonia absorber 18.

[0068] Ammonia distillation column 17 is used to distill dilute ammonia water after heat exchange treatment by the ammonia distillation heat exchanger 19 to obtain purified ammonia gas.

[0069] The ammonia distillation cooler 20 is used to condense the purified ammonia gas into liquid ammonia for use.

[0070] In this embodiment of the invention, by further configuring ammonia recovery and processing equipment, the separated ammonia gas can be effectively utilized in practical applications, thereby improving economic efficiency.

[0071] In the ammonia recovery and treatment equipment, more preferably, the ammonia recovery and treatment equipment further includes an oil removal filter, which is used to remove oil from the crude ammonia gas before it is introduced into the ammonia purification tower 16, thereby improving the purification effect of the subsequent ammonia purification tower.

[0072] In the ammonia purification tower, more preferably, the ammonia purification tower 16 further includes a circulation pump for circulating and washing the crude ammonia gas with dilute ammonia water in the ammonia purification tower 16, thereby improving the purification effect based on circulation and washing.

[0073] In the integrated gas-water pretreatment and phenol-ammonia recovery system described in this utility model, such as Figure 3 As shown, preferably, the crude phenol purification equipment includes:

[0074] Crude phenol purification tower 21 is used to purify crude phenol from the phenol recovery tower 5.

[0075] Phenol vapor condenser 22 is used to condense crude phenol vapor output from the top of the crude phenol purification tower 21;

[0076] Phenol storage tank 23 is used to store phenol products that have condensed into a liquid phase.

[0077] In this embodiment of the invention, by further purifying the crude phenol using a crude phenol purification tower 21 and a phenol vapor condenser 22, the final purity of the crude phenol can reach more than 83%, thereby enabling better recycling of the crude phenol.

[0078] In this utility model, the external dimensions of the deacidification tower 1 are as follows: The equipment weighs approximately 86 tons; it has 28 anti-clogging trays and a 4500mm x 2 random packing layer on top. The main material is 304+Q345R composite plate. Operating pressure: 0.28-0.3MPa, operating temperature: 40-138℃, design pressure: 0.72MPa, design temperature: 190℃.

[0079] Specifically, the main process operating parameters for deacidification tower 1 are as follows: cold feed temperature is 30-40℃, hot feed temperature is 130-135℃, cold-hot feed ratio is 0.25, tower top pressure is 0.26-0.30MPa, tower top temperature is 40-100℃, acid gas exhaust temperature is 40-60℃, tower bottom pressure is 0.28-0.32MPa, and tower bottom temperature is 135-138℃.

[0080] The ammonia removal tower 2 has a shell diameter of φ4600mm, a cylinder height of approximately 40300mm, and a total weight of approximately 130t. It has 46 anti-clogging trays, primarily made of 304+Q345R composite plate. Operating pressure: 0.3-0.32MPa, operating temperature: 136-146℃, design pressure: 0.72MPa, design temperature: 190℃.

[0081] Specifically, the main process operating parameters for ammonia removal in ammonia removal tower 2 are as follows: tower top pressure is 0.28-0.32 MPa, tower top temperature is 135-139℃, tower bottom pressure is 0.30-0.34 MPa, tower bottom temperature is 145-147℃, and the external ammonia vapor recovery rate of the ammonia removal tower is 11-13%.

[0082] The external dimensions of the extraction tower 3 are as follows: The equipment weighs approximately 68 tons. Internally, it contains 3000mm x 2 and 4500mm x 4 grid-structured packing material, primarily constructed from 304+Q345R composite plates. Operating pressure: atmospheric pressure to 0.24MPa; operating temperature: 40-70℃; design pressure: 0.60MPa; design temperature: 120℃.

[0083] Specifically, the coal gas-water treated by the deammoniation tower 2 enters the extraction tower from the top, while the extractant in the extractant tank 15 enters from the bottom of the extraction tower, where they come into countercurrent contact inside, thus achieving better removal of phenols. The principle of phenol removal through extraction is based on the characteristic that the solubility of phenol in the extractant is greater than its solubility in water, causing phenolic substances in the phenolic water to transfer to the extractant, thereby achieving phenol removal. The extraction tower 3 can be a single stage or a multi-stage system connected in series, preferably two stages connected in series.

[0084] More specifically, the main process operating parameters for extraction in extraction tower 3 are: pressure: atmospheric pressure; ratio (volume ratio of extractant to phenol water): 1:4.5-1:6; extraction temperature: 50-75℃; extraction pH: 5.5-6.5.

[0085] Water tower 4, also known as a solvent stripping tower, contains both dissolved and entrained solvents in the phenol water after extraction and phenol removal. The preheated phenol water is sent to the water tower to remove both dissolved and entrained solvents. The purified water, after solvent removal, is cooled to below 40°C via a heat exchanger and cooler before being sent to the biochemical section. Specifically, the main process operating parameters for solvent stripping in water tower 4 are: water tower pressure: atmospheric pressure; water tower top temperature: 95-98°C; water tower bottom temperature: 105-110°C.

[0086] The extract from extraction tower 3 is preheated to 95-105℃ via a heat exchanger and then sent to phenol recovery tower 5 for distillation separation. The extraction solvent, as the light component, is collected from the top of the tower, condensed, and then enters the extractant tank 15, while the crude phenol, as the heavy component, is collected from the bottom of the tower. Specifically, the main process operating parameters for solvent recovery in phenol recovery tower 5 are: phenol tower pressure: atmospheric pressure; phenol tower top temperature: ~113℃; phenol tower bottom temperature: 200-215℃; reflux ratio: 0.25.

[0087] The function of the crude phenol purification tower is to refine and purify the crude phenol from the phenol recovery tower through distillation. The tower is filled with packing material. The shell diameter is φ1600mm, the height is approximately 22000mm, and the total weight is approximately 22t. It has three sections of packing material, primarily 304+Q345R composite plate. Operating pressure: -0.088~-0.086MPa, operating temperature: 120-180℃, design pressure: 0.35MPa, design temperature: 220℃. Specifically, the crude phenol from the phenol recovery tower is pumped to the crude phenol purification tower. Midstream oil is collected from the bottom of the purification tower and pumped to the tank farm. Crude phenol vapor at the top of the purification tower 21 is condensed by the phenol vapor condenser 22 and flows by gravity into the phenol storage tank 23. Part of the condensed liquid phenol product can be returned to the purification tower as top reflux, and part can be sent to the phenol storage tank 23.

[0088] More specifically, the main process operating parameters for the crude phenol purification tower are as follows: feed temperature: 140-200℃; crude phenol purification tower pressure: -0.085~-0.07MPa; crude phenol purification tower top temperature: 110-145℃; crude phenol purification tower bottom temperature: 165-205℃; reflux ratio: 0.6-1.0.

[0089] Crude ammonia gas from the ammonia gas-liquid separation unit enters the ammonia purification tower 16 from the bottom. It then undergoes countercurrent washing with dilute ammonia water in the tower. Phenol, hydrogen sulfide, carbon dioxide, and small amounts of water and ammonia in the ammonia gas are absorbed into the dilute ammonia water. The purified crude ammonia gas is then collected from the top of the ammonia purification tower. Specifically, the main process operating parameters for washing in the ammonia purification tower 16 are: top temperature ≤ 58℃, bottom pressure ≥ 0.15MPa. The main process operating parameters for distillation in the ammonia distillation tower 17 are: distillation pressure: 1.6MPa; top temperature: 40-70℃; bottom temperature: 205℃; reflux ratio: 0.9-1.0.

[0090] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0091] Example 1

[0092] Adopting such Figure 1-2The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization shown is implemented for the pretreatment of gas and water. Specifically, the integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization includes:

[0093] The deacidification tower 1 has a cold material inlet at the top, through which one stream of coal gas and water is cooled and then introduced into the cold material inlet. The upper middle part has a preheating material inlet, through which another stream of coal gas and water is preheated and then introduced into the preheating material inlet, for the purpose of deacidification treatment of coal gas and water.

[0094] An acid gas treatment device for treating acid gas from the top of the deacidification tower 1;

[0095] Ammonia removal tower 2, wherein one material inlet at the top is connected to the bottom of the acid removal tower 1, and the other material inlet is connected to the alkali tank 10, is used to remove ammonia from the coal gas water after acid removal treatment by the acid removal tower 1;

[0096] An ammonia gas-liquid separation device is used to separate the ammonia gas-liquid mixture from the top of the ammonia removal tower 2 to obtain crude ammonia gas.

[0097] An ammonia recovery and processing device is used to recover crude ammonia gas from the ammonia gas-liquid separation device into liquid ammonia.

[0098] Extraction tower 3, the upper part of which is connected to the bottom of the deammoniation tower 2 and the bottom of which is connected to the extractant tank 15, is used to remove phenol from the coal gas water after it has been deammonised by the deammoniation tower 2;

[0099] The phenol recovery tower 5, whose upper part is connected to the top of the extraction tower 3, is used to separate phenol and extractant from the extract from the extraction tower 3 and to return the extractant at the top to the extractant tank 15.

[0100] A crude phenol purification device, wherein the upper part is connected to the bottom of the phenol recovery tower 5, and is used to purify the crude phenol from the phenol recovery tower 5.

[0101] Water tower 4, the upper part of which is connected to the bottom of the extraction tower 3, is used to separate the extractant from the coal gas water after the phenol removal treatment of the extraction tower 3 and send it to the subsequent biochemical treatment, and to return the separated extractant to the extractant tank 15.

[0102] Specifically, a cooler 6 is installed upstream of the cold feed inlet of the deacidification tower 1 to cool the coal gas-water mixture to a set cooling temperature; a preheater is installed upstream of the preheating feed inlet of the deacidification tower 1 to preheat the coal gas-water mixture to a set preheating temperature; the preheater includes a primary heat exchanger 7, a secondary heat exchanger 8, and a tertiary heat exchanger 9 connected in series with progressively increasing heat exchange temperatures; the acid gas treatment equipment includes a condenser 14 to separate the liquid phase from the acid gas and send it to the boiler for incineration; the ammonia gas-liquid separation equipment includes a primary condenser 11, a secondary condenser 12, and a tertiary condenser 13 connected in series, wherein the primary condenser 11, the secondary condenser 12, and the tertiary condenser 13 sequentially treat the ammonia gas-liquid mixture. The phases are cooled and separated to obtain crude ammonia. A first heat exchanger is installed on the connecting pipe between the bottom of the deammoniation tower 2 and the upper middle part of the extraction tower 3 to exchange heat with the coal gas water after deammoniation treatment in the deammoniation tower 2 to a first set temperature. A second heat exchanger is installed on the connecting pipe between the top of the extraction tower 3 and the upper middle part of the phenol recovery tower 5 to exchange heat with the extract to a second set temperature. A third heat exchanger is installed on the connecting pipe between the bottom of the extraction tower 3 and the upper middle part of the water tower 4 to exchange heat with the coal gas water after phenol removal treatment in the extraction tower 3 to a third set temperature. The extractant in the extractant tank 15 is methyl isobutyl ketone, and the alkaline solution in the alkali tank 10 is NaOH solution.

[0103] In practical applications, one stream of the coal gas-water mixture is cooled to 35°C by cooler 6 and then enters deacidification tower 1 through the cold feed inlet. Simultaneously, another stream is preheated to 132°C through primary heat exchanger 7, secondary heat exchanger 8, and tertiary heat exchanger 9 before entering deacidification tower 1 through the preheated feed inlet. The acidic gas separated by stripping then escapes from the top of deacidification tower 1 and, under the action of condenser 14, is separated into a liquid phase and sent to the boiler for combustion. The coal gas-water mixture treated by deacidification tower 1 is pumped from its bottom into the middle of deammoniation tower 2. At the same time, the NaOH solution in alkali tank 10 is pumped into the upper part of deammoniation tower 2. Then, the ammonia-liquid mixture enters the ammonia-liquid separation device from the top of deammoniation tower 2. Under the action of the condenser in the ammonia-liquid separation device, crude ammonia gas with a completely separated liquid phase is obtained. The crude ammonia gas is then processed by the ammonia recovery equipment. The gas is recovered as liquid ammonia. After being deamed by the deaming tower 2, the gas-water mixture is pumped out from the bottom and heated to 45°C by the first heat exchanger before being fed into the top of the extraction tower 3. At the same time, the extractant in the extractant tank 15 is pumped into the bottom of the extraction tower 3. Then, the extract from the top of the extraction tower 3 is heated to 100°C by the second heat exchanger before being fed into the phenol recovery tower 5. The gas-water mixture after phenol removal from the bottom is heated to 75°C by the third heat exchanger before being fed into the water tower 4. The phenol recovery tower 5 separates the phenol and extractant from the extract and returns the extractant from the top to the extractant tank 15 for recycling. The crude phenol discharged from the bottom is purified by the crude phenol purification equipment. The water tower 4 separates the extractant from the gas-water mixture after phenol removal from the extraction tower 3 and sends it to subsequent biochemical treatment. The separated extractant is returned to the extractant tank 15 for recycling.

[0104] Testing has shown that the integrated gas-water pretreatment and phenol-ammonia recovery system described in this invention can effectively remove acidic gases, ammonia, and phenol from gas-water, and realize the recovery and utilization of phenol and ammonia as well as the recycling of the extractant.

[0105] Example 2

[0106] Referring to Embodiment 1, the difference is that it also includes an ammonia recovery and treatment device, which includes:

[0107] Ammonia purification tower 16 is used to purify incoming crude ammonia gas by washing it with dilute ammonia water.

[0108] Ammonia absorber 18 is used to absorb ammonia gas purified by the ammonia purification tower 16 into dilute ammonia water.

[0109] Ammonia distillation heat exchanger 19 is used to perform heat exchange treatment on dilute ammonia water from the ammonia absorber 18.

[0110] Ammonia distillation column 17 is used to distill dilute ammonia water after heat exchange treatment by the ammonia distillation heat exchanger 19 to obtain purified ammonia gas.

[0111] Ammonia distillation cooler 20 is used to condense purified ammonia gas into liquid ammonia for use.

[0112] The ammonia recovery and treatment equipment also includes an oil removal filter, which is used to remove oil from the crude ammonia gas before it is introduced into the ammonia purification tower 16.

[0113] The ammonia purification tower 16 also includes a circulation pump for circulating and washing the crude ammonia gas with dilute ammonia water inside the ammonia purification tower 16.

[0114] Testing revealed that the integrated gas-water pretreatment and phenol-ammonia recovery system described in this invention, compared to the scheme in Example 1, can better recover and utilize the separated ammonia as liquid ammonia, thereby effectively improving economic benefits.

[0115] Example 3

[0116] Referring to Example 2, the difference is that the crude phenol purification equipment includes:

[0117] Crude phenol purification tower 21 is used to purify crude phenol from the phenol recovery tower 5.

[0118] Phenol vapor condenser 22 is used to condense crude phenol vapor output from the top of the crude phenol purification tower 21;

[0119] Phenol storage tank 23 is used to store phenol products that have condensed into a liquid phase.

[0120] Testing revealed that the integrated gas-water pretreatment and phenol-ammonia recovery system described in this invention, compared to the scheme in Example 2, can increase the purity of crude phenol to over 83%, thereby effectively improving economic benefits.

[0121] This utility model provides an integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization. By setting up an acid removal tower, acidic gases in the coal gas and water can be effectively removed. Furthermore, by setting up an ammonia removal tower, ammonia in the coal gas and water can be effectively removed. Furthermore, by setting up an extraction tower, phenol in the coal gas and water can be effectively removed, thereby effectively removing acidic gases, ammonia, and phenol from the coal gas and water. Furthermore, by setting up an ammonia gas-liquid separation device, an ammonia recovery and treatment device, and a crude phenol purification device, phenol and ammonia can be recovered and utilized. Furthermore, by setting up a phenol recovery tower and a water tower, the extractant can be recovered and recycled.

[0122] The preferred embodiments of this utility model have been described in detail above; however, this utility model is not limited thereto. Within the scope of the technical concept of this utility model, various simple modifications can be made to the technical solution of this utility model. To avoid unnecessary repetition, this utility model will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed by this utility model and all fall within the protection scope of this utility model.

Claims

1. An integrated system for coal gas and water pretreatment and phenol and ammonia recovery and utilization, characterized in that, The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization includes: A deacidification tower (1) is provided at the top with a cold material inlet. One stream of coal gas water is cooled and then fed into the cold material inlet. A preheating material inlet is provided in the middle and upper part. Another stream of coal gas water is preheated and then fed into the preheating material inlet, which is used to deacidify the coal gas water. An acid gas treatment device for treating acid gases from the top of the deacidification tower (1); Ammonia removal tower (2), wherein one material inlet at the top is connected to the bottom of the acid removal tower (1), and the other material inlet is connected to the alkali tank (10), for removing ammonia from the coal gas water after acid removal treatment by the acid removal tower (1); Ammonia gas-liquid separation equipment is used to separate the ammonia gas-liquid mixture from the top of the ammonia removal tower (2) to obtain crude ammonia gas; An ammonia recovery and processing device is used to recover crude ammonia gas from the ammonia gas-liquid separation device into liquid ammonia. An extraction tower (3) is connected at the top to the bottom of the deammoniation tower (2) and at the bottom to the extractant tank (15), and is used to remove phenol from the coal gas water after it has been deammonised by the deammoniation tower (2); A phenol recovery tower (5), the upper part of which is connected to the top of the extraction tower (3), is used to separate phenol and extractant from the extract from the extraction tower (3) and to return the extractant at the top to the extractant tank (15). A crude phenol purification device, wherein the upper part is connected to the bottom of the phenol recovery tower (5) for purifying crude phenol from the phenol recovery tower (5); Water tower (4), the upper part of which is connected to the bottom of the extraction tower (3), is used to separate the extractant from the coal gas water after the phenol removal treatment of the extraction tower (3) and send it to the subsequent biochemical treatment, and to return the separated extractant to the extractant tank (15).

2. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to claim 1, characterized in that, A cooler (6) is provided upstream of the cold material inlet of the deacidification tower (1) to cool the coal gas water to a set cooling temperature; a preheater is provided upstream of the preheating material inlet of the deacidification tower (1) to preheat the coal gas water to a set preheating temperature.

3. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to claim 2, characterized in that, The preheater includes a primary heat exchanger (7), a secondary heat exchanger (8), and a tertiary heat exchanger (9) connected in series with their heat exchange temperatures increasing sequentially.

4. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to claim 1, characterized in that, The acid gas treatment equipment includes a condenser (14) for separating the liquid phase in the acid gas and sending it to a boiler for incineration.

5. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to claim 1, characterized in that, The ammonia gas-liquid separation equipment includes a primary condenser (11), a secondary condenser (12), and a tertiary condenser (13) connected in series. The primary condenser (11), the secondary condenser (12), and the tertiary condenser (13) sequentially cool and separate the ammonia gas-liquid mixture to obtain crude ammonia gas.

6. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to any one of claims 1-5, characterized in that, The ammonia recovery and treatment equipment includes: Ammonia purification tower (16) is used to purify incoming crude ammonia gas by washing it with dilute ammonia water. Ammonia absorber (18) is used to absorb ammonia gas purified by the ammonia purification tower (16) into dilute ammonia water; Ammonia distillation heat exchanger (19) is used to perform heat exchange treatment on dilute ammonia water from the ammonia absorber (18); The ammonia distillation column (17) is used to distill the dilute ammonia water after heat exchange treatment by the ammonia distillation heat exchanger (19) to obtain purified ammonia gas. Ammonia distillation cooler (20) is used to condense purified ammonia gas into liquid ammonia for use.

7. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to claim 6, characterized in that, The ammonia recovery and treatment equipment also includes an oil removal filter, which is used to remove oil from the crude ammonia gas before the crude ammonia gas is introduced into the ammonia purification tower (16); The ammonia purification tower (16) also includes a circulation pump for circulating and washing the crude ammonia gas with dilute ammonia water in the ammonia purification tower (16).

8. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to claim 1, characterized in that, The crude phenol purification equipment includes: Crude phenol purification tower (21) is used to purify crude phenol from the phenol recovery tower (5); A phenol vapor condenser (22) is used to condense the crude phenol vapor output from the top of the crude phenol purification tower (21); Phenol storage tank (23) is used to store phenol products that have condensed into a liquid phase.

9. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to claim 1, characterized in that, A first heat exchanger is provided on the connecting pipe between the bottom of the deammoniation tower (2) and the upper middle part of the extraction tower (3) to exchange heat with the coal gas water after deammoniation treatment by the deammoniation tower (2) to a first set temperature; a second heat exchanger is provided on the connecting pipe between the top of the extraction tower (3) and the upper middle part of the phenol recovery tower (5) to exchange heat with the extract to a second set temperature; a third heat exchanger is provided on the connecting pipe between the bottom of the extraction tower (3) and the upper middle part of the water tower (4) to exchange heat with the coal gas water after dephenolization treatment by the extraction tower (3) to a third set temperature.

10. The integrated system for gas-water pretreatment and phenol-ammonia recovery and utilization according to claim 1, characterized in that, The extractant in the extractant tank (15) is any one of benzene, heavy benzene, light oil, heavy solvent oil, isopropyl ether, tributyl phosphate and methyl isobutyl ketone.

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