Apparatus and method for determining the ammonium carbonate content in ammonium bicarbonate

Abstract

This invention relates to a measuring device and method. The invention discloses a device for determining the ammonium carbonate content in ammonium bicarbonate, comprising a reaction vessel, a gas collecting bottle, a water receiving bottle, and an automatic lifting interlocking system. The invention also provides a method for determining the ammonium carbonate content in ammonium bicarbonate using the aforementioned measuring device. The device and method for determining the ammonium carbonate content in ammonium bicarbonate of this invention are suitable for detection and control during the manufacturing and use of ammonium bicarbonate, and are simple, rapid, low-cost, and highly applicable. Besides ammonium bicarbonate, it can also be used for products such as sodium carbonate, potassium carbonate, and calcium carbonate.

Description

Technical Field

[0001] The invention relates to a measuring device and a method, in particular to a measuring device and a method for determining the content of ammonium carbonate in ammonium bicarbonate. Background Art

[0002] The preparation method of ammonium bicarbonate generally uses a certain concentration of ammonia water as a raw material, and uses carbon dioxide to perform a carbonation reaction to prepare ammonium bicarbonate, and then obtains the ammonium bicarbonate product by centrifugal solid-liquid separation. Therefore, in the carbonation process, it is necessary to control the carbonization degree in the reaction system to determine the end point. If the carbonization degree is insufficient, the ammonium carbonate content in the produced ammonium bicarbonate is high, which will affect the subsequent performance; if in order to ensure the carbonization degree, the time of passing carbon dioxide can only be extended, but this will also cause waste of carbon dioxide and cause environmental pollution.

[0003] In addition, during the use of ammonium bicarbonate, such as in the production of potassium bicarbonate by ion exchange, if the ammonium carbonate in the ammonium bicarbonate solution is too high, the ion exchange will not produce pure potassium bicarbonate, but a mixture of potassium bicarbonate and potassium carbonate, which will affect the evaporation and crystallization of potassium bicarbonate and product quality.

[0004] There is currently no simple and feasible method to determine the ammonium carbonate content in ammonium bicarbonate; this is because ammonium bicarbonate and ammonium carbonate cannot be detected by the acid-base titration step-by-step method, because ammonium bicarbonate and ammonium carbonate react with hydrochloric acid or sulfuric acid in an equimolar ratio when neutralized, and the ammonium chloride or ammonium sulfate formed after the reaction is also a buffer salt, making the reaction end point unclear.

[0005] Literature reports that potassium carbonate in potassium bicarbonate can be removed by first precipitating carbonate ions with barium chloride, and then titrated with hydrochloric acid or sulfuric acid standard solution to calculate the content of potassium carbonate and potassium bicarbonate. However, the ammonium carbonate content in ammonium bicarbonate cannot be analyzed by precipitation method, because ammonium bicarbonate itself is unstable. After ammonium carbonate is precipitated with barium chloride, ammonium bicarbonate decomposes to form part of ammonium carbonate, and a certain balance will always be formed, which makes the precipitation method inapplicable.

[0006] Literature reports that sodium carbonate in sodium bicarbonate, or potassium carbonate in potassium bicarbonate, can be analyzed by high-temperature calcination method, and the content of sodium bicarbonate or potassium bicarbonate can be calculated by calcination weight loss, thereby obtaining the content of sodium carbonate or potassium carbonate.

[0007] However, both ammonium bicarbonate and ammonium carbonate will decompose at high temperatures, so the burning method is not applicable. Therefore, a method and equipment for detecting the content of ammonium carbonate in ammonium bicarbonate are needed to solve the problems encountered in current production and quality inspection. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a simple, rapid and low-cost device and method for determining the content of ammonium carbonate in ammonium bicarbonate.

[0009] In order to solve the above technical problems, the present invention provides a device for determining the content of ammonium carbonate in ammonium bicarbonate, comprising a reaction container, a gas collecting bottle, a water receiving bottle and an automatic lifting interlocking system.

[0010] As an improvement of the device for determining the content of ammonium carbonate in ammonium bicarbonate of the present invention: a feed port, a connection port and an exhaust port are provided on the reaction container, and the reaction container is placed in a heating device; a constant pressure funnel for feeding is provided at the feed port, and the outlet of the constant pressure funnel is connected to the feed port through a regulating valve;

[0011] The gas collecting bottle is a bottle body with scales and is in an inverted state, and a bottle mouth plug is arranged at the bottle mouth of the gas collecting bottle; the inner cavity at the bottom of the gas collecting bottle is connected to the exhaust pipe through a vent valve;

[0012] The water receiving bottle is a bottle body with scales, a bottle plug is arranged at the bottle mouth of the water receiving bottle, and the exhaust pipe is sealed and passes through the bottle plug to communicate with the inner cavity of the water receiving bottle; a connecting port is arranged at the side wall of the water receiving bottle near the bottom; the water receiving bottle is placed on a lifting platform, and a linkage control lifter with a lifting motor is arranged at the bottom of the lifting platform;

[0013] One end of the U-shaped pipe is sealedly connected to the exhaust port, and the other end is sealedly passed through the bottle mouth plug to the bottom of the gas collecting bottle;

[0014] The installation height of the reaction vessel is higher than that of the gas collecting bottle;

[0015] One end of the discharge pipe is sealed through the bottle mouth plug and communicated with the inner cavity of the gas collecting bottle; the other end of the discharge pipe is sealed and connected to the connecting port of the water receiving bottle;

[0016] The automatic lifting interlocking system includes a laser liquid level monitor I, a laser liquid level monitor II, a linkage control slider, an interlocking controller, and a linkage control lifter; the laser liquid level monitor I is used to monitor the liquid level of the gas collecting bottle, and the laser liquid level monitor II is used to monitor the liquid level of the water receiving bottle; the linkage control slider is a slider with a motor, and the linkage control slider is mounted on the iron frame platform II and is connected to the iron frame platform II for movement; the linkage control slider is fixedly connected to the laser liquid level monitor I and the laser liquid level monitor II respectively;

[0017] The laser liquid level monitor I, the laser liquid level monitor II, the motor of the linkage control slide block, and the lifting motor of the linkage control lifter are respectively connected with the interlocking controller signal.

[0018] As a further improvement of the measuring device of the ammonium carbonate content in the ammonium bicarbonate of the present invention:

[0019] A thermometer is provided at the connection port; a ground-mouth stopper is provided at the inlet of the constant pressure funnel.

[0020] As a further improvement of the measuring device of the ammonium carbonate content in the ammonium bicarbonate of the present invention:

[0021] The bottom of the gas collecting bottle is externally connected with a thermometer and a pressure gauge.

[0022] As a further improvement of the measuring device of the ammonium carbonate content in the ammonium bicarbonate of the present invention:

[0023] A fixing ring is arranged on the outer surface of the gas collecting bottle, and the fixing ring is fixed to the iron frame.

[0024] As a further improvement of the measuring device of the ammonium carbonate content in the ammonium bicarbonate of the present invention:

[0025] A magnetic stirrer is placed in the reaction vessel.

[0026] In the present invention, the liquid discharge pipe used for connecting the gas collecting bottle and the water receiving bottle is a transparent silicone hose.

[0027] The present invention also provides a method for determining the content of ammonium carbonate in ammonium bicarbonate using the above-mentioned determination device, comprising the following steps:

[0028] 1) First fill the gas collecting bottle with water;

[0029] 2) Turn on the laser liquid level monitor I to track and monitor the liquid level in the gas collecting bottle, and transmit the liquid level information to the interlocking controller. The interlocking controller controls the linkage control slider to move up and down along the iron frame, thereby ensuring that the height of the laser liquid level monitor I is consistent with the actual liquid level height of the gas collecting bottle;

[0030] At the same time, since the laser liquid level monitor II is fixedly connected to the linkage control slider, the laser liquid level monitor II also moves up and down accordingly, and transmits the liquid level information to the interlocking controller, and the interlocking controller controls the linkage control lifter to move up and down, thereby ensuring that the actual liquid level height of the water receiving bottle is consistent with the height of the laser liquid level monitor II;

[0031] Thereby, the liquid levels of the gas collecting bottle and the water receiving bottle are kept level;

[0032] 3) Add the ammonium bicarbonate solution to be tested into the reaction container through the feed port;

[0033] 4) Add sulfuric acid solution into the constant pressure funnel; open the regulating valve, and drip the sulfuric acid solution into the reaction vessel through the feed port for reaction;

[0034] 5) The carbon dioxide gas generated by the reaction in the reaction container is introduced into the bottom of the gas collecting bottle through the exhaust port and the U-shaped pipe. The water in the gas collecting bottle is driven by the carbon dioxide and discharged into the water receiving bottle through the drain pipe;

[0035] As the amount of carbon dioxide produced by the sulfuric acid drop reaction increases, the liquid level in the gas collecting bottle decreases accordingly. The laser liquid level monitor I tracks and monitors the liquid level in the gas collecting bottle, and controls the linkage control slider to move up and down through the interlocking controller to keep the laser liquid level monitor I and the liquid level in the gas collecting bottle at the same height.

[0036] At the same time, the liquid level in the water receiving bottle also rises, and the laser liquid level monitor II tracks and monitors the liquid level in the water receiving bottle with scale, and controls the rise and fall of the lifting device through the interlocking controller to keep the laser liquid level monitor II and the liquid level in the water receiving bottle with scale at the same height.

[0037] 6) When no more carbon dioxide bubbles are generated after sulfuric acid is dripped into the reaction vessel, stop dripping sulfuric acid and read the liquid levels in the gas collecting bottle and the water receiving bottle by scale;

[0038] 7) Obtain the ammonium carbonate content in ammonium bicarbonate by calculation.

[0039] As an improvement of the determination method of ammonium carbonate content in ammonium bicarbonate of the present invention:

[0040] The step 7) comprises the following:

[0041] 7.1) Calculate the molar concentration of carbon dioxide according to formula (1):

[0042]

[0043] In formula (1):

[0044] C 1 —The molar concentration of carbon dioxide in the ammonium bicarbonate solution to be tested, in mol / L;

[0045] T 0 —Standard temperature, value is 273.15K;

[0046] t—the temperature of the gas in the gas collecting bottle, in °C;

[0047] Vm—gas molar volume under standard conditions (gas constant), 22.4L / mol;

[0048] V—measured displacement, in mL;

[0049] V 1 —The volume of ammonium bicarbonate solution to be tested;

[0050] Note: The measured displacement is the liquid drop in the gas collecting bottle or the rising volume of water in the water receiving bottle. The two volumes should be equal. If the deviation between the two exceeds 3%, the experiment needs to be repeated.

[0051] 7.2) Total ammonia content C of the ammonium bicarbonate solution to be tested 3 Determination of (formaldehyde method and ammonia method);

[0052] 7.3) Calculation of ammonium carbonate concentration in ammonium bicarbonate solution:

[0053] The concentration of ammonium carbonate is expressed as A 1 The concentration of ammonium bicarbonate is expressed as (in g / L) and calculated according to formula (3); 2 Expressed (in g / L), calculated according to formula (4).

[0054] A 1 =(C 3 -C 1 )×96.09…………(3)

[0055] A 2 =(C 1 ×79.06)-(A 1 ×79.06÷96.09)…………(4).

[0056] As a further improvement of the method for determining the content of ammonium carbonate in ammonium bicarbonate of the present invention: C 3 The calculation formula is:

[0057] C 3 =C 2 ×V 2 / V 1 …………………………(2)

[0058] C 3 The unit is mol / L;

[0059] In formula (2):

[0060] C 2 —Concentration of sodium hydroxide standard titration solution, in mol / L;

[0061] V 2 —titration volume of sodium hydroxide standard solution, in mL;

[0062] V 1 ——The volume of ammonium bicarbonate solution measured, in mL.

[0063] The present invention has proved through a large number of experiments that the formaldehyde ammonium method is used to measure NH 4 +The content or concentration of CO is then measured by acid reaction and drainage method. 2 The volume (or amount) of ammonium carbonate and ammonium bicarbonate is calculated and the content or concentration of ammonium carbonate and ammonium bicarbonate is obtained. However, there is no relatively simple and suitable equipment for measuring volume by drainage method at present, so the present invention has developed a set of special equipment through a lot of research and design.

[0064] The device and method for determining the content of ammonium carbonate in ammonium bicarbonate of the present invention are suitable for detection and control during the manufacture and use of ammonium bicarbonate, and are simple, fast, low-cost, and highly applicable. In addition to being used for ammonium bicarbonate, they can also be used for products such as sodium carbonate, potassium carbonate, and calcium carbonate. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0066] Figure 1 The invention discloses a half-section structural schematic diagram of a device and method for determining the content of ammonium carbonate in ammonium bicarbonate.

[0067] In the figure: ground stopper 1, constant pressure funnel 2, thermometer 3, valve 4, feed port 5, connection port 6, exhaust port 7, three-mouth reaction bottle 8, U-shaped pipe 9, thermometer 10; connection port 11, pressure gauge 12, valve 13, exhaust pipe 14, vent valve 15, gas collecting bottle 16, fixing ring 17, bottle mouth stopper 18, iron frame 19, discharge pipe 20; laser liquid level monitor I 21, laser liquid level monitor II 23, linkage control slider 22, interlocking controller 24, iron frame 25, exhaust pipe 26, valve 27, bottle stopper 28, water receiving bottle 29, connection port 30; lifting platform 31, linkage control lifter 32. DETAILED DESCRIPTION

[0068] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0069] Embodiment 1: A device for determining the content of ammonium carbonate in ammonium bicarbonate, comprising a reaction vessel, a gas collecting bottle 16, a water receiving bottle 29 and an automatic lifting interlocking system. The reaction vessel is a three-necked reaction bottle 8.

[0070] A feed port 5, a connection port 6 and an exhaust port 7 are provided on the three-necked reaction flask 8, and the three-necked reaction flask 8 is placed in an oil bath; a thermometer 3 is provided at the connection port 6; a constant pressure funnel 2 for feeding is provided at the feed port 5, a ground-mouth plug 1 is provided at the inlet of the constant pressure funnel 2, and the outlet of the constant pressure funnel 2 is connected to the feed port 5 through an adjusting valve 4, the thermometer 3 is a mercury thermometer with a measuring range of 0-100°C and a graduation of 1°C, the constant pressure funnel 2 has a volume of 50ml, the three-necked reaction flask 8 has a volume of 250ml, and is made of colorless, transparent hard glass.

[0071] The gas collecting bottle 16 is a gas collecting bottle with scales and is in an inverted state, so the mouth of the gas collecting bottle 16 faces downward, and a bottle mouth plug 18 is provided at the bottle mouth of the gas collecting bottle 16 .

[0072] The thermometer 10 is connected to the inner cavity at the bottom of the gas collecting bottle 16 through the connection port 11, and the inner cavity at the bottom of the gas collecting bottle 16 is connected to the pressure gauge 12 through the valve 13; the inner cavity at the bottom of the gas collecting bottle 16 is also connected to the exhaust pipe 14 through the vent valve 15. The pressure gauge 12 is an absolute pressure gauge (with a range of 0-10Kpa); the thermometer 10 has a range of 0-50℃ and a mercury thermometer with a graduation of 0.1℃; the gas collecting bottle 16 is a graduated gas collecting bottle with a volume of 5L (with a minimum graduation of 50ml) and is made of colorless transparent hard glass. A fixing ring 17 is provided on the outer surface of the gas collecting bottle 16, and the fixing ring 17 is fixed to the iron frame 19, thereby ensuring that the gas collecting bottle 16 is fixed vertically and stably.

[0073] The water receiving bottle 29 is a bottle body with scales, a bottle stopper 28 is arranged at the bottle mouth of the water receiving bottle 29, and the exhaust pipe 26 is sealed through the bottle stopper 28 and communicated with the inner cavity of the water receiving bottle 29; a valve 27 is arranged on the exhaust pipe 26; and a connecting port 30 is arranged at the side wall near the bottom of the water receiving bottle 29. The water receiving bottle 29 is a bottle body with scales, and its volume is 5L (the minimum division is 50ml), and the material is colorless transparent hard glass. The water receiving bottle 29 is placed on a lifting platform 31, and a linkage control lifter 32 is arranged at the bottom of the lifting platform 31. The linkage control lifter 32 is a linkage control lifter 32 with a lifting motor.

[0074] One end of the U-shaped pipe 9 is sealedly connected to the exhaust port 7 of the three-mouth reaction bottle 8, and the other end is sealedly passed through the bottle mouth plug 18 to the bottom of the gas collecting bottle 16.

[0075] The installation height of the three-necked reaction bottle 8 should be higher than the gas collecting bottle 16 , that is, the lowest point of the three-necked reaction bottle 8 should be higher than the highest point of the gas collecting bottle 16 to prevent the liquid in the gas collecting bottle 16 from flowing back.

[0076] One end of the drain pipe 20 is sealed through the bottle mouth plug 18 and communicated with the inner cavity of the gas collecting bottle 16; the other end of the drain pipe 20 is sealed and connected to the connecting port 30 of the water receiving bottle 29, thereby communicating with the bottom of the inner cavity of the water receiving bottle 29. The graduated drain pipe 20 is a transparent silicone hose, which is easy to extend and retract and rise and fall.

[0077] The automatic lifting interlocking system includes a laser liquid level monitor I 21, a laser liquid level monitor II 23, a linkage control slider 22, an interlocking controller 24, and a linkage control lifter 32; the linkage control slider 22 is a slider with a motor, and the linkage control slider 22 is mounted on the iron frame 25 and can move up and down along the iron frame 25. The linkage control slider 22 is fixedly connected to the laser liquid level monitor I 21 and the laser liquid level monitor II 23.

[0078] The laser liquid level monitor I 21 and the laser liquid level monitor II 23 are respectively connected to the interlocking controller 24 signals, and the interlocking controller 24 is respectively connected to the motor of the linkage control slider 22 and the lifting motor of the linkage control lifter 32 signals.

[0079] The laser liquid level monitor Ⅰ21 monitors the liquid level of the gas collecting bottle 16 and transmits the liquid level information to the interlocking controller 24. The interlocking controller 24 controls the linkage control slider 22 to move up and down along the iron frame 25, thereby ensuring that the height of the laser liquid level monitor Ⅰ21 is consistent with the actual liquid level height of the gas collecting bottle 16.

[0080] At the same time, since the laser liquid level monitor Ⅱ23 is also fixedly connected to the linkage control slider 22, the laser liquid level monitor Ⅱ23 also moves up and down accordingly, and transmits this liquid level information to the interlocking controller 24. The interlocking controller 24 controls the linkage control lifter 32 to move up and down, thereby ensuring that the actual liquid level height of the water receiving bottle 29 is consistent with the height of the laser liquid level monitor Ⅱ23.

[0081] Thereby, the liquid levels of the gas collecting bottle 16 and the water receiving bottle 29 are kept level.

[0082] That is, the laser liquid level monitor Ⅰ21 tracks and monitors the liquid level in the scaled gas collecting bottle 16, and controls the linkage control slider 22 to move up and down through the interlocking controller 24 to keep the laser liquid level monitor Ⅰ21 and the liquid level in the gas collecting bottle 16 always at the same height.

[0083] The laser liquid level monitor II 23 tracks and monitors the liquid level in the water receiving bottle 29 with scale, and controls the rise and fall of the lifting device 32 through the interlocking controller 24 to keep the laser liquid level monitor II 23 and the liquid level in the water receiving bottle 29 with scale always maintained at the same height.

[0084] In the present invention, all parts can be obtained through conventional commercial forms. For example, the laser liquid level monitor I 21 and the laser liquid level monitor II 23 can be purchased from the GOLDY-10G laser glass liquid level gauge produced by Beijing Harman Electronics Co., Ltd.; the interlocking controller 24 can be purchased from the DKC-220 programmable stepper servo motor controller (PLC motion controller) produced by Shanghai Yibiao Technology; the linkage control lifter 32 can be purchased from the stepper push rod (gear) with a stroke of 150 mm produced by Changzhou Louis Electric Push Rod Co., Ltd.; the linkage control slider 22 can be purchased from the RXP60-300 synchronous belt linear CNC electric slide guide module produced by Chengdu Liandong Ruixin Technology Co., Ltd.

[0085] The thermometer 3 measures the reaction temperature of the materials in the three-necked reaction bottle 8 .

[0086] The temperature measured by the thermometer 10 is the temperature of the gas in the gas collecting bottle 16, that is, the temperature corresponding to t(gas in the gas collecting bottle 16) in the following formula (1).

[0087] The function of the vent valve 15 is to empty the gas collecting bottle 16 when it is filled with water; that is, when water is added to the gas collecting bottle 16 through the exhaust pipe 14, the vent valve 15 is opened and the air in the gas collecting bottle 16 is emptied.

[0088] The function of the pressure gauge 12 is to measure the pressure of the gas collecting bottle 16; therefore, when it is necessary to measure the pressure of the gas collecting bottle 16, the valve 13 is opened.

[0089] The function of the valve 27 and the exhaust pipe 26 is to exhaust the gas in the water receiving bottle 29 when measuring, so that the pressure inside the bottle is equal to the atmospheric pressure.

[0090] Example 2: A method for determining the content of ammonium carbonate in ammonium bicarbonate, using the device described in Example 1, the actual use process is as follows:

[0091] 1. At the beginning of the test, the three ports of the three-port reaction bottle 8 are all in an open state; that is, the connection between the exhaust port 7 and the U-shaped pipe 9 is disconnected, and the connection between the feed constant pressure funnel 2 and the feed port 5 is disconnected;

[0092] First, fill the graduated gas collecting bottle 16 with water through the vent valve 15 and the exhaust pipe 14 , then close the vent valve 15 , seal the exhaust port 7 and the U-shaped pipe 9 , and open the vent valve 27 .

[0093] 2. Turn on the laser liquid level monitor Ⅰ21 to track and monitor the liquid level in the gas collecting bottle 16 with a scale, and transmit this liquid level information to the interlocking controller 24. The interlocking controller 24 controls the linkage control slider 22 to move up and down along the iron frame 25, thereby ensuring that the height of the laser liquid level monitor Ⅰ21 is consistent with the actual liquid level height of the gas collecting bottle 16.

[0094] At the same time, since the laser liquid level monitor Ⅱ23 is also fixedly connected to the linkage control slider 22, the laser liquid level monitor Ⅱ23 also moves up and down accordingly, and transmits this liquid level information to the interlocking controller 24. The interlocking controller 24 controls the linkage control lifter 32 to move up and down, thereby ensuring that the actual liquid level height of the water receiving bottle 29 is consistent with the height of the laser liquid level monitor Ⅱ23.

[0095] Thereby, the liquid levels of the gas collecting bottle 16 and the water receiving bottle 29 are kept level.

[0096] Before the reaction is carried out, there is no water in the water receiving bottle 29 . Therefore, the connection port 30 of the water receiving bottle 29 is much higher than the bottle mouth of the gas collecting bottle 16 . Therefore, the water in the gas collecting bottle 16 cannot be discharged into the water receiving bottle 29 through the drain pipe 20 .

[0097] 3. Put an appropriate amount of ammonium bicarbonate solution as the test product into the three-necked reaction bottle 8 through the feed port 5 of the three-necked reaction bottle 8, add a magnetic stirrer into the three-necked reaction bottle 8, then connect the feed constant pressure funnel 2 with the feed port 5, and connect the thermometer 3 with the connection port 6;

[0098] 4. Open the ground stopper 1 and add 50 ml of 50% sulfuric acid into the constant pressure funnel 2. After the sulfuric acid is added, cover it with the ground stopper 1.

[0099] Turn on the magnetic stirrer and slowly open the regulating valve 4, and drip sulfuric acid into the three-necked reaction bottle 8 through the feed inlet 5 for reaction.

[0100] 5. The carbon dioxide gas produced by the reaction in the three-necked reaction bottle 8 is introduced into the bottom of the gas collecting bottle 16 with a scale through the exhaust port 7 and the U-shaped pipe 9. The water in the gas collecting bottle 16 is driven by the carbon dioxide and discharged into the water receiving bottle 29 with a scale through the drain pipe 20.

[0101] As the amount of carbon dioxide produced by the sulfuric acid addition reaction increases, the liquid level in the gas collecting bottle 16 decreases accordingly. The laser liquid level monitor Ⅰ21 tracks and monitors the liquid level in the scaled gas collecting bottle 16, and controls the linkage control slider 22 to move up and down through the interlocking controller 24 to keep the laser liquid level monitor Ⅰ21 and the liquid level in the gas collecting bottle 16 always maintained at the same height.

[0102] At the same time, the liquid level in the water receiving bottle 29 with scale also rises. The laser liquid level monitor II 23 tracks and monitors the liquid level in the water receiving bottle 29 with scale, and controls the rise and fall of the lifting device 32 through the interlocking controller 24 to keep the laser liquid level monitor II 23 and the liquid level in the water receiving bottle 29 with scale always maintained at the same height.

[0103] 6. When no carbon dioxide bubbles are generated after sulfuric acid is added (i.e., no bubbles are generated in the three-necked reaction bottle 8 and the liquid level in the gas collecting bottle 16 no longer drops), stop adding sulfuric acid, read the liquid levels in the gas collecting bottle 16 and the water receiving bottle 29 through the scale, calculate the volume of carbon dioxide, and read the temperature at the same time.

[0104] According to PV = nRT, at the same pressure, the volume of the same mole of gas is proportional to the temperature. The molar concentration of carbon dioxide can be calculated according to formula (1):

[0105]

[0106] In formula (1):

[0107] C 1 —The molar concentration of carbon dioxide in the ammonium bicarbonate solution to be tested, in mol / L;

[0108] T 0 —Standard temperature, value is 273.15K.

[0109] t—temperature of the gas in the gas collecting bottle 16, in °C;

[0110] Vm—gas molar volume under standard conditions (gas constant), 22.4L / mol;

[0111] V—measured displacement, in mL

[0112] V 1 —The volume of ammonium bicarbonate solution of the product to be tested;

[0113] Note: The measured displacement is the liquid drop in the gas collecting bottle 16 or the rising volume of water in the water receiving bottle 29. The two volumes should be equal. If the deviation between the two exceeds 3%, the experiment needs to be repeated.

[0114] 7. Determination of total ammonia content (formaldehyde method) Use a pipette to accurately transfer the ammonium bicarbonate solution (same as the ammonium bicarbonate solution in step 3) as the test product, and the volume is V 1 , transfer to a 250mL conical flask, add water to 80mL, add 3 drops of methyl red indicator (0.1%, m / m), adjust with 30% sulfuric acid solution until the solution turns red, heat and boil for 3min, cool to room temperature, adjust with sodium hydroxide solution (about 0.5N) until the red color just disappears, add 10mL neutral formaldehyde solution (20%, m / m), let stand for 5min, add 3 drops of phenolphthalein indicator (0.1%, m / m), and use sodium hydroxide standard solution (concentration meter is C 2 ) is titrated until the reddish color does not fade within 30 seconds as the end point, and the volume of the consumed sodium hydroxide standard solution (the amount of 0.5 mol / L sodium hydroxide standard solution used for titration) is recorded as V2 .

[0115] The total ammonia content in the ammonium bicarbonate solution to be tested is expressed as C 3 The unit is mol / L, calculated according to formula (2)

[0116] C 3 =C 2 ×V 2 / V 1 …………………………(2)

[0117] Where:

[0118] C 2 —Concentration of sodium hydroxide standard titration solution, in mol / L;

[0119] V 2 —titration volume of sodium hydroxide standard solution, in mL;

[0120] V 1 ——The volume of ammonium bicarbonate solution measured, in mL;

[0121] 8. Calculation of ammonium carbonate concentration in ammonium bicarbonate solution. The concentration of ammonium carbonate is expressed as A 1 The concentration of ammonium bicarbonate is expressed as (in g / L) and calculated according to formula (3); 2 Expressed (in g / L), calculated according to formula (4).

[0122] A 1 =(C 3 -C 1 )×96.09…………(3)

[0123] A 2 =C 1 ×79.06-A 1 ×79.06÷96.09…………(4)

[0124] Where:

[0125] 96.09—Molar mass value of ammonium carbonate, in g / moL;

[0126] 79.06—Molar mass value of ammonium bicarbonate, in g / moL.

[0127] Experiment 1: Determination of the content of ammonium carbonate in ammonium bicarbonate, according to the method described in Example 2, is as follows:

[0128] 1. Transfer 1.5152g ammonium carbonate (content 99.0%) and 29.2308g ammonium bicarbonate (content 97.5%) into a 100ml volumetric flask, add distilled water to dissolve at room temperature, and dilute to 100ml. The ammonium carbonate in the obtained ammonium bicarbonate solution is 15.00g / L and the ammonium bicarbonate is 285.00g / L. This is used as the sample to be tested - ammonium bicarbonate sample solution.

[0129] 2. Fill the scaled gas collecting bottle 16 with water through the vent valve 15 and the exhaust pipe 14, then close the vent valve 15, connect the exhaust port 7 and the U-shaped pipe 9, and open the vent valve 27. Turn on the laser liquid level monitor I 21 to track and monitor the liquid level in the scaled gas collecting bottle 16, and control the linkage control slider 22 to move up and down through the interlocking controller 24 to keep the laser liquid level monitor I 21 and the liquid level in the gas collecting bottle 16 at the same height. At the same time, turn on the laser liquid level monitor II 23 to track and monitor the liquid level in the scaled water receiving bottle 29, and control the linkage control lifter 32 to rise and fall through the interlocking controller 24 to keep the laser liquid level monitor II 23 and the liquid level in the scaled water receiving bottle 29 at the same height.

[0130] 3. Take 50 ml of the ammonium bicarbonate sample solution described in step 1 above and put it into the three-necked reaction bottle 8, add a magnetic stirrer, then connect the feeding constant pressure funnel 2 with the feeding port 5, and connect the thermometer 3 with the connecting port 6; open the ground stopper 1, add 50 ml of 50% sulfuric acid by mass concentration into the constant pressure funnel 2, and cover the ground stopper 1 after the sulfuric acid is added. Turn on the magnetic stirrer, and slowly open the regulating valve 4, and the sulfuric acid is dripped into the three-necked reaction bottle 8 through the feeding port 5 for reaction. The carbon dioxide gas generated by the reaction in the three-necked reaction bottle 8 is introduced into the bottom of the gas collecting bottle 16 with scale through the exhaust port 7 and the U-shaped pipe 9. The water in the gas collecting bottle 16 is discharged into the water receiving bottle 29 with scale through the drain pipe 20 under the impetus of carbon dioxide. As the amount of carbon dioxide produced by the sulfuric acid drop reaction increases, the liquid level in the gas collecting bottle 16 decreases accordingly, and the laser liquid level monitor I 21 tracks and monitors the liquid level in the scaled gas collecting bottle 16, and controls the linkage control slider 22 to move up and down through the interlocking controller 24 to keep the laser liquid level monitor I 21 and the liquid level in the gas collecting bottle 16 at the same height. At the same time, the liquid level in the scaled water receiving bottle 29 also rises accordingly, and the laser liquid level monitor II 23 tracks and monitors the liquid level in the scaled water receiving bottle 29, and controls the linkage control lift 32 to rise and fall through the interlocking controller 24 to keep the laser liquid level monitor II 23 and the liquid level in the scaled water receiving bottle 29 at the same height.

[0131] 4. When no more carbon dioxide bubbles are produced after sulfuric acid is added, stop adding sulfuric acid, read the liquid levels in the gas collecting bottle 16 and the water receiving bottle 29 by scale, and calculate the volume of carbon dioxide to be 4.58L (4580ml), and read the temperature to be 24.5°C. Calculate the molar concentration of carbon dioxide in the ammonium bicarbonate solution to be tested according to formula (1): 1 It is 3.7526mol / L.

[0132] C1=273.15×4580 / ((273.15+24.5)×22.4×50)=3.7526mol / L.

[0133] 5. Use a pipette to accurately transfer 5.0 mL of the above ammonium bicarbonate sample, transfer it to a 250 mL conical flask, add water to 80 mL, add 3 drops of methyl red indicator (0.1%, m / m), adjust the solution with 30% sulfuric acid solution until it turns red, heat and boil for 3 minutes, cool to room temperature, adjust the solution with 0.5012 mol / L sodium hydroxide solution until the red color just disappears, add 10 mL of neutral formaldehyde solution (20%, m / m), let stand for 5 minutes, add 3 drops of phenolphthalein indicator (0.1%, m / m), and titrate with 0.5012 mol / L sodium hydroxide standard solution until the red color does not fade within 30 seconds as the end point. Record the volume of sodium hydroxide standard solution consumed as 39.08 ml. Calculate according to formula (2), C 3＝ (0.5012×39.08) / 5=3.9174mol / L;

[0134] Therefore, the total ammonia content in the sample is C 3 It is 3.9174mol / L.

[0135] 6. Calculation of ammonium carbonate concentration in ammonium bicarbonate solution:

[0136] According to formula (3), A 1 =(3.9174-3.7526)×96.09=15.8356

[0137] According to formula (4), A 2 =(C 1 ×79.06)-(A 1 ×79.06÷96.09)=(3.7526×79.06)-(15.8356×79.06÷96.09)=283.65.

[0138] Therefore, the concentration of ammonium carbonate is expressed as A 1 is 15.8356 g / L; according to formula (4), the concentration of ammonium bicarbonate is calculated as A 2The relative deviation of ammonium bicarbonate concentration is only about 0.47%, and the relative deviation of ammonium carbonate is about 5.33%, which meets the production control requirements.

[0139] Experiment 2: Determination of the content of ammonium carbonate in ammonium bicarbonate, according to the method described in Example 2, is as follows:

[0140] 1. Transfer 7.576 g of ammonium carbonate (content 99.0%) and 23.0769 g of ammonium bicarbonate (content 97.5%) into a 100 ml volumetric flask, add distilled water to dissolve at room temperature, and adjust the volume to 100 ml. The ammonium carbonate content in the obtained ammonium bicarbonate solution is 75.00 g / L and the ammonium bicarbonate content is 225.00 g / L.

[0141] 2. Fill the scaled gas collecting bottle 16 with water through the vent valve 15 and the exhaust pipe 14, then close the vent valve 15, connect the exhaust port 7 and the U-shaped pipe 9, and open the vent valve 27. Turn on the laser liquid level monitor I 21 to track and monitor the liquid level in the scaled gas collecting bottle 16, and control the linkage control slider 22 to move up and down through the interlocking controller 24 to keep the laser liquid level monitor I 21 and the liquid level in the gas collecting bottle 16 at the same height. At the same time, turn on the laser liquid level monitor II 23 to track and monitor the liquid level in the scaled water receiving bottle 29, and control the linkage control lifter 32 to rise and fall through the interlocking controller 24 to keep the laser liquid level monitor II 23 and the liquid level in the scaled water receiving bottle 29 at the same height.

[0142] 3. Take 50 ml of the ammonium bicarbonate sample solution described in step 1) above and put it into the three-necked reaction bottle 8, add a magnetic stirrer, then connect the feeding constant pressure funnel 2 with the feeding port 5, and connect the thermometer 3 with the connecting port 6; open the ground stopper 1, add 50 ml of 50% sulfuric acid by mass concentration into the feeding constant pressure funnel 2, and cover the ground stopper 1 after the sulfuric acid is added. Turn on the magnetic stirrer, and slowly open the regulating valve 4, and the sulfuric acid is dripped into the three-necked reaction bottle 8 through the feeding port 5 for reaction. The carbon dioxide gas generated by the reaction in the three-necked reaction bottle 8 is introduced into the bottom of the gas collecting bottle 16 with scale through the exhaust port 7 and the U-shaped pipe 9, and the water in the gas collecting bottle 16 is discharged into the water receiving bottle 29 with scale through the drain pipe 20 under the impetus of carbon dioxide. As the amount of carbon dioxide produced by the sulfuric acid drop reaction increases, the liquid level in the gas collecting bottle 16 decreases accordingly, and the laser liquid level monitor I 21 tracks and monitors the liquid level in the scaled gas collecting bottle 16, and controls the linkage control slider 22 to move up and down through the interlocking controller 24 to keep the laser liquid level monitor 21 and the liquid level in the gas collecting bottle 16 at the same height. At the same time, the liquid level in the scaled water receiving bottle 29 also rises accordingly, and the laser liquid level monitor II 23 tracks and monitors the liquid level in the scaled water receiving bottle 29, and controls the linkage control lift 32 to rise and fall through the interlocking controller 24 to keep the laser liquid level monitor II 23 and the liquid level in the scaled water receiving bottle 29 at the same height.

[0143] 4. When no more carbon dioxide bubbles are generated after sulfuric acid is added, stop adding sulfuric acid, read the liquid levels in the gas collecting bottle 16 and the water receiving bottle 29 through the scale, and calculate the volume of carbon dioxide to be 4.45L, and the temperature to be 25.3°C. According to PV=nRT, at the same pressure, the volume of the same number of moles of gas is proportional to the temperature. According to formula (1), the molar concentration of carbon dioxide C1 is calculated to be 3.6363 mol / L.

[0144] 5. Use a pipette to accurately transfer 5.0 mL of the above ammonium bicarbonate sample, transfer it to a 250 mL conical flask, add water to 80 mL, add 3 drops of methyl red indicator (0.1%, m / m), adjust the solution with 30% sulfuric acid solution until it turns red, heat and boil for 3 minutes, cool to room temperature, adjust the solution with 0.5012 mol / L sodium hydroxide solution until the red color just disappears, add 10 mL of neutral formaldehyde solution (20%, m / m), let stand for 5 minutes, add 3 drops of phenolphthalein indicator (0.1%, m / m), and titrate with 0.5012 mol / L sodium hydroxide standard solution until the red color does not fade within 30 seconds as the end point, and record the volume of sodium hydroxide standard solution consumed as 43.96 ml. Calculate the total ammonia content C in the sample according to formula (2): 3 4.4065mol / L;

[0145] 6. Calculation of ammonium carbonate concentration in ammonium bicarbonate solution: According to formula (3), the concentration of ammonium carbonate is expressed as A 1 is 74.01 g / L; according to formula (4), the concentration of ammonium bicarbonate is calculated as A 2 The relative deviation of ammonium bicarbonate concentration is only 0.71%, and the relative deviation of ammonium carbonate is 1.32%, which meets the production control requirements.

[0146] Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A device for measuring the content of ammonium carbonate in ammonium bicarbonate, characterized in that: It comprises a reaction container, a gas collecting bottle (16), a water receiving bottle (29) and an automatic lifting interlocking system; The reaction container is provided with a feed port (5), a connection port (6) and an exhaust port (7), and the reaction container is placed in a heating device; a constant pressure funnel (2) for feeding is provided at the feed port (5), and the outlet of the constant pressure funnel (2) is connected to the feed port (5) through a regulating valve (4); The gas collecting bottle (16) is a bottle body with scales and is in an inverted state. A bottle mouth plug (18) is provided at the bottle mouth of the gas collecting bottle (16); the inner cavity at the bottom of the gas collecting bottle (16) is connected to the exhaust pipe (14) through a vent valve (15); The water receiving bottle (29) is a bottle body with scales, a bottle stopper (28) is arranged at the bottle mouth of the water receiving bottle (29), and the exhaust pipe (26) is connected with the inner cavity of the water receiving bottle (29) after passing through the bottle stopper (28) in a sealed manner; a connecting port (30) is arranged at the side wall of the water receiving bottle (29) near the bottom; the water receiving bottle (29) is placed on a lifting platform (31), and a linkage control lifter (32) with a lifting motor is arranged at the bottom of the lifting platform (31); One end of the U-shaped pipe (9) is sealedly connected to the exhaust port (7), and the other end is sealedly passed through the bottle mouth plug (18) to the bottom of the gas collecting bottle (16); The installation height of the reaction container is higher than that of the gas collecting bottle (16); One end of the liquid discharge pipe (20) is sealed through the bottle mouth plug (18) and communicates with the inner cavity of the gas collecting bottle (16); the other end of the liquid discharge pipe (20) is sealed and connected to the connecting port (30) of the water receiving bottle (29); The automatic lifting interlocking system comprises a laser liquid level monitor I (21), a laser liquid level monitor II (23), a linkage control slider (22), an interlocking controller (24), and a linkage control lifter (32); the laser liquid level monitor I (21) is used to monitor the liquid level of a gas collecting bottle (16), the laser liquid level monitor II (23) is used to monitor the liquid level of a water receiving bottle (29), the linkage control slider (22) is a slider with a motor, the linkage control slider (22) is mounted on an iron frame platform II (25) and is movably connected to the iron frame platform II (25); the linkage control slider (22) is fixedly connected to the laser liquid level monitor I (21) and the laser liquid level monitor II (23) respectively; The laser liquid level monitor I (21), the laser liquid level monitor II (23), the motor of the linkage control slider (22), and the lifting motor of the linkage control lifter (32) are respectively connected to the interlocking controller (24) by signal.

2. The measuring device for ammonium carbonate content in ammonium bicarbonate according to claim 1, characterized in that: A thermometer is provided at the connection port (6); A ground-mouth stopper (1) is provided at the inlet of the constant pressure funnel (2).

3. The measuring device for ammonium carbonate content in ammonium bicarbonate according to claim 2, characterized in that: The bottom of the gas collecting bottle (16) is externally connected to a thermometer and a pressure gauge.

4. The measuring device for ammonium carbonate content in ammonium bicarbonate according to claim 3, characterized in that: A fixing ring (17) is provided on the outer surface of the gas collecting bottle (16), and the fixing ring (17) is fixed to an iron frame platform (19).

5. The measuring device for ammonium carbonate content in ammonium bicarbonate according to claim 4, characterized in that: A magnetic stirrer is placed in the reaction vessel.

6. A method for determining the content of ammonium carbonate in ammonium bicarbonate using a measuring device as described in any one of claims 1 to 5, characterized in that The following steps are involved: 1) First, fill the gas collecting bottle (16) with water; 2) Turn on the laser liquid level monitor I (21) to track and monitor the liquid level in the gas collecting bottle (16), and transmit the liquid level information to the interlocking controller (24). The interlocking controller (24) controls the linkage control slider (22) to move up and down along the iron frame platform II (25), thereby ensuring that the height of the laser liquid level monitor I (21) is consistent with the actual liquid level height of the gas collecting bottle (16); At the same time, since the laser liquid level monitor II (23) is fixedly connected to the linkage control slider (22), the laser liquid level monitor II (23) also moves up and down accordingly, and transmits the liquid level information to the interlocking controller (24). The interlocking controller (24) controls the linkage control lifter (32) to move up and down, thereby ensuring that the actual liquid level height of the water receiving bottle (29) is consistent with the height of the laser liquid level monitor II (23); Thereby, the liquid levels of the gas collecting bottle (16) and the water receiving bottle (29) are kept level; 3) feeding the ammonium bicarbonate solution as the sample to be tested into the reaction container through the feed port (5); 4) Add the sulfuric acid solution into the constant pressure funnel (2); open the regulating valve (4), and the sulfuric acid solution drips into the reaction container through the feed port (5) to react; 5) The carbon dioxide gas generated by the reaction in the reaction container is introduced into the bottom of the gas collecting bottle (16) through the exhaust port (7) and the U-shaped pipe (9), and the water in the gas collecting bottle (16) is discharged into the water receiving bottle (29) through the drain pipe (20) under the impetus of the carbon dioxide; As the amount of carbon dioxide generated by the sulfuric acid drop reaction increases, the liquid level in the gas collecting bottle (16) decreases accordingly, and the laser liquid level monitor I (21) tracks and monitors the liquid level in the gas collecting bottle (16), and controls the linkage control slider (22) to move up and down through the interlocking controller (24), so as to keep the laser liquid level monitor I (21) and the liquid level in the gas collecting bottle (16) always at the same height; At the same time, the liquid level in the water receiving bottle (29) also rises accordingly, and the laser liquid level monitor II (23) tracks and monitors the liquid level in the water receiving bottle (29) with scale, and controls the rise and fall of the lifting device (32) through the interlocking controller (24), so as to keep the laser liquid level monitor II (23) and the liquid level in the water receiving bottle (29) with scale at the same height. 6) When no more carbon dioxide bubbles are generated after sulfuric acid is dripped into the reaction container, stop dripping sulfuric acid and read the liquid levels in the gas collecting bottle (16) and the water receiving bottle (29) by scale; 7) Obtain the ammonium carbonate content in ammonium bicarbonate by calculation.

7. The method for determining the content of ammonium carbonate in ammonium bicarbonate according to claim 6, wherein: The step 7) comprises the following: 7.1) Calculate the molar concentration of carbon dioxide according to formula (1): In formula (1): C1—the molar concentration of carbon dioxide in the ammonium bicarbonate solution to be tested, in mol / L; T0—standard temperature, value is 273.15K; t—temperature of the gas in the gas collecting bottle (16), unit: °C; Vm—gas molar volume under standard conditions, 22.4L / mol; V—measured displacement, unit: mL; V1—volume of ammonium bicarbonate solution to be tested; 7.2) Determination of the total ammonia content C3 of the ammonium bicarbonate solution to be tested; 7.3) Calculation of ammonium carbonate concentration in ammonium bicarbonate solution: The concentration of ammonium carbonate is represented by A1 and is calculated according to formula (3); A1=(C3-C1)×96.09......(3).

8. The method for determining the content of ammonium carbonate in ammonium bicarbonate according to claim 7, wherein The calculation formula of C3 is: C3=C2×V2 / V1……………………(2) The unit of C3 is mol / L; In formula (2): C2—concentration of sodium hydroxide standard titration solution, in mol / L; V2—titration volume of sodium hydroxide standard solution, in mL; V1——The volume of ammonium bicarbonate solution measured, in mL.

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