Method for producing glycine and iminodiacetic acid using high-concentration coalbed methane

Abstract

This application discloses a method for producing glycine and iminodiacetic acid using high-concentration coalbed methane, comprising the following steps: ammoniation reaction; alkaline deammoniation; ion-exchange membrane separation; decolorization; concentration and crystallization; GLY crystallization separation; resin separation; GLY purification; and IDA purification. This invention can reduce liquid alkali consumption (based on the production of 1 ton of industrial-grade glycine) by 550–600 kg / t, sulfuric acid consumption by 680–740 kg / t, activated carbon consumption by 25–35 kg / t, and sodium sulfate (byproduct) yield by 1000–1100 kg / t. The total production cost of glycine is reduced by more than 1000 yuan / ton. Furthermore, in subsequent process flows, because the decolorization solution and crystallization mother liquor contain only small amounts of impurities such as sodium sulfate, the separation, crystallization, and purification of glycine and iminodiacetic acid (heat-sensitive materials) are easier, resulting in superior product quality.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to a method for producing glycine and iminodiacetic acid by utilizing high-concentration coalbed methane. Background Art

[0002] In the existing process for producing glycine and iminodiacetic acid, in the alkaline deamination and acid decolorization process, 32-42% liquid alkali NaOH is directly used to carry out alkaline hydrolysis reaction with the amination reaction liquid (aminoacetonitrile, iminodiacetonitrile) to generate basic salts of sodium glycine and sodium iminodiacetic acid, and then after deamination treatment, the deaminated liquid is neutralized with 98% sulfuric acid to generate glycine and monosodium iminodiacetic acid and sodium sulfate, and then activated carbon is used for decolorization treatment. The process has a 100% consumption of alkali (based on the production of 1 ton of industrial-grade glycine) of 720-750kg / t, sulfuric acid consumption of 1000-1100kg / t, activated carbon consumption of 80-100kg / t, and sodium sulfate (by-product) output of ~1500kg / t. In addition, in the subsequent process production process, since the decolorizing liquid and crystallization mother liquor contain a large amount of impurities such as sulfate, it is difficult to separate (heat-sensitive materials) glycine and iminodiacetic acid and to purify them by crystallization. Repeated recycling of the mother liquor will lead to increased energy consumption and increased impurities in the mother liquor system. Summary of the invention

[0003] In view of this, the present application provides a method for producing glycine and iminodiacetic acid using high-concentration coalbed methane, aiming to solve the problems of high raw material consumption, large amount of by-product sodium sulfate, difficulty in separation and purification, and high production cost in the prior art in the production of glycine and iminodiacetic acid.

[0004] The embodiment of the present application is implemented as follows: a method for producing glycine and iminodiacetic acid using high-concentration coalbed methane comprises the following steps:

[0005] Amination reaction: Hydroxyacetonitrile and concentrated ammonia water are mixed and reacted to obtain an amination reaction solution A;

[0006] Alkaline deamination: the amination reaction liquid A undergoes alkaline deamination reaction with liquid alkali to obtain alkaline hydrolysis liquid B and gaseous ammonia;

[0007] Ion membrane separation: using an ion membrane to perform electrodialysis separation on the alkaline solution B to obtain an electrodialysis solution C;

[0008] Decolorization: The electrodialysis solution C is subjected to decolorization to remove colored impurities and filtration to obtain a decolorized filtrate D;

[0009] Concentration and crystallization: Decolorization filtrate D is concentrated and crystallized to obtain concentrated filtrate E;

[0010] GLY crystallization separation: The concentrated filtrate E is subjected to GLY crystallization separation to obtain GLY industrial grade filter cake and primary mother liquor F;

[0011] Resin separation: The primary mother liquor F, which accounts for 10% to 30% of the total mass of the primary mother liquor F, is subjected to resin separation to obtain a secondary mother liquor G, which is returned to the concentration and crystallization process for reuse; the resin separation also obtains an extract H;

[0012] GLY refining: purify and refine GLY industrial-grade filter cake to obtain food-grade glycine;

[0013] IDA refining: The extract H is subjected to the first IDA refining and the second IDA refining to obtain electronic grade iminodiacetic acid.

[0014] In some embodiments, the mass concentration of hydroxyacetonitrile is 49% to 51%, and the pH of hydroxyacetonitrile is 1.5 to 3; and / or

[0015] The concentration of concentrated ammonia water is 20% to 35%; and / or

[0016] The molar ratio of hydroxyacetonitrile to concentrated aqueous ammonia is 1:2.1 to 1:4.5; and / or

[0017] The weight content of GLY in the GLY industrial grade filter cake is 98%.

[0018] In some embodiments, hydroxyacetonitrile and concentrated ammonia water are mixed and preheated to temperature T1, and reacted at temperature T2 and pressure P1 for a reaction time of t1 to obtain an amination reaction solution A; and / or

[0019] The ammoniation reaction liquid A is mixed with liquid alkali and continuously enters the alkaline deamination reactor at pressure P2 and temperature T3 to carry out alkaline deamination reaction, and the residual ammonia remaining in the reaction liquid is removed by a deamination tower to obtain alkaline hydrolysis liquid B; and / or

[0020] The alkaline hydrolyzate B is separated by an ion membrane, and the salt chamber generates an electrodialysis solution C, and the alkaline chamber generates NaOH and H2O; and / or

[0021] Electrodialysis solution C is subjected to pH adjustment at temperature T4, and activated carbon is used to remove colored impurities in the feed solution, and then filtered through a membrane core to obtain a decolorized filtrate D; and / or

[0022] The decolorized filtrate D enters an evaporation concentration device to evaporate excess water and remove 40% to 90% by mass of Na2SO4 to obtain a concentrated filtrate E, which is concentrated and crystallized to obtain a by-product of sodium sulfate; and / or

[0023] GLY industrial-grade filter cake is subjected to GLY refining, crystallization separation, drying and airing in sequence to obtain food-grade glycine; and / or

[0024] The first IDA refining comprises: adjusting the pH value of the extract H to 1.9-2.1 with sulfuric acid at room temperature and pressure, and then evaporating and concentrating, desalting, cooling and crystallizing, centrifuging and drying to obtain industrial-grade iminodiacetic acid, and sending 30%-50% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining as waste liquid I to an incinerator for harmless incineration treatment; and / or

[0025] The second IDA refining includes heating and dissolving industrial-grade iminodiacetic acid with desalted water, and then undergoing high-efficiency decolorization, removing heavy metal impurities with a complexing agent, fine filtration, cooling crystallization, centrifugal separation, vacuum drying, and screening to obtain electronic-grade iminodiacetic acid.

[0026] In some embodiments, T1 is 40°C to 60°C; and / or

[0027] T2 is 55°C to 110°C; and / or

[0028] P1 is 0.5Mpa to 2.5Mpa; and / or

[0029] t1 is 3 min to 10 min; and / or

[0030] P2 is -95Kpa~-30Kpa; and / or

[0031] T3 is 50°C to 110°C; and / or

[0032] T4 is 50°C to 90°C; and / or

[0033] Adjust the pH value to 4-7 with concentrated sulfuric acid; and / or

[0034] The activated carbon accounts for 1‰ to 3‰ of the total mass of the feed liquid; and / or

[0035] Colored impurities include nitrile char and / or polypeptide polymers; and / or

[0036] The removal rate of Na2SO4 is 40% to 90%.

[0037] In some embodiments, the removed gaseous ammonia is added with water to recover 20% to 35% concentrated ammonia water, which is returned to the step of amination reaction for reuse; and / or

[0038] The NaOH and H2O generated in the alkali chamber are returned to the alkaline deamination step and reused as alkali solution; and / or

[0039] The primary mother liquor F accounting for 70% to 90% of the total mass of the primary mother liquor F is returned to the concentration and crystallization step for reuse; and / or

[0040] 50% to 70% by weight of the IDA circulating crystallization mother liquor produced in the first IDA purification is returned to the concentration and crystallization step.

[0041] In some embodiments, the amination reaction solution A comprises 15% to

[0042] 22% NH2CH2CN, 1.0% to 2.5% NH(CH2CN)2, 3% to 8% NH3, trace amounts of HOCH2CN and nitrile polymers, and the balance being water; and / or

[0043] Alkaline hydrolysis solution B, by mass percentage, includes 15% to 30% NH2CH2COONa, 1% to 4% IDA-2Na, 1% to 3% NaOH, trace amounts of other impurities, and the balance is water, and trace amounts of other impurities include sodium hydroxyacetate and sodium salt of nitrile polymer; and / or

[0044] Electrodialysis solution C, by mass percentage, comprises 12% to 25% GLY, 1% to 3% IDA-Na, trace water-soluble sodium salt impurities, and the balance is water, wherein the trace water-soluble sodium salt impurities include sodium hydroxyacetate and sodium salt of nitrile polymer; and / or

[0045] The decolorized filtrate D comprises, by mass percentage, 15% to 20% GLY, 2% to 4% IDA-Na, 1% to 5% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water, wherein the trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; and / or

[0046] The concentrated filtrate E comprises, by mass percentage, 25% to 35% GLY, 2% to 8% IDA-Na, 5% to 8% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water, wherein the trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; and / or

[0047] The primary mother liquor F comprises, by mass percentage, 18% to 25% GLY, 4% to 10% IDA-Na, 6% to 10% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water, wherein the trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; and / or

[0048] The secondary mother liquor G comprises, by mass percentage, 6% to 15% GLY, 0.1% to 1% IDA-Na, a trace amount of sodium sulfate, and the balance is water; and / or

[0049] Extract H, by mass percentage, comprises 6% to 12% GLY, 1% to 5% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water, the trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; and / or

[0050] Waste liquid I, by mass percentage, comprises 0.5% to 5% IDA-Na, 3% to 10% Na2SO4, 5% to 10% glycolic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the remainder is water; and / or

[0051] The IDA circulating crystallization mother liquor comprises 0.5% to 5% IDA-Na, 3% to 10% Na2SO4, 5% to 10% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water.

[0052] In some embodiments, obtaining hydroxyacetonitrile comprises the following steps:

[0053] High-concentration coalbed methane is removed through the PSA impurity removal device to obtain methane;

[0054] Methane reacts with ammonia and air to produce hydrocyanic acid;

[0055] Hydrocyanic acid reacts with formaldehyde to obtain hydroxyacetonitrile.

[0056] In some embodiments, the high-concentration coalbed methane includes, by mass percentage, 90% to 97% methane, 3% to 8% N2+O2, and the remainder is ethane, propane, butane, H2S and CO2; and / or

[0057] The mass concentration of formaldehyde is 36.5% to 37%; and / or

[0058] The molar ratio of hydrocyanic acid to formaldehyde is 1:1.01-1.2; and / or

[0059] The mass concentration of hydroxyacetonitrile is 49% to 51%.

[0060] In some embodiments, the high-concentration coalbed methane is subjected to a PSA impurity removal device to obtain a desorbed gas tail boiler for incineration, wherein the desorbed gas comprises, by mass percentage, 88% to 96% methane, 4% to 12% N2+O2, and the remainder is ethane, propane, butane, H2S and CO2; and / or

[0061] Methane is preheated to a temperature of T5, mixed evenly with ammonia and air at a premixed temperature of T6, and then enters a fixed bed reactor to undergo methane ammoxidation reaction at a high temperature of T7 with a pressure of P3 under the action of a platinum mesh catalyst to obtain a synthetic reaction gas A, and then the synthetic gas A is sent to an acid washing tower for residual ammonia absorption and gas cooling to obtain a synthetic gas B with a mass content of hydrocyanic acid of M4, wherein the synthetic reaction gas A includes HCN, NH3, CH4, N2, CO, CO2, O 2、 H2O; synthesis gas B includes HCN, H2SO4, CH4, N2, CO, CO2, and O2.

[0062] In some embodiments, T5 is 50°C to 80°C; and / or

[0063] T6 is 50°C to 80°C; and / or

[0064] P3 is 0.07MPa to 0.15MPa; and / or

[0065] T7 is 1000°C to 1200°C; and / or

[0066] M4 is 8% to 12%; and / or

[0067] The molar ratio of methane, ammonia and air is 1:1.05~1.2:5.5~7.0.

[0068] In this application:

[0069] GLY is glycine;

[0070] GLY-Na is sodium glycinate;

[0071] IDA is iminodiacetic acid;

[0072] IDA-2Na is disodium iminodiacetic acid;

[0073] IDA-Na is iminodiacetic acid monosodium salt.

[0074] In the present application, the alkaline solution (sodium hydroxide) produced by ion membrane separation is directly subjected to alkaline hydrolysis reaction with the amination reaction solution A (aminoacetonitrile, iminodiacetonitrile) to generate basic salts of sodium glycine and sodium iminodiacetic acid, and then electrodialysis separation is performed using an ion membrane separation process to generate glycine and monosodium iminodiacetic acid, and then a small amount of concentrated sulfuric acid and activated carbon are used for acidification and decolorization. This process can successfully realize the conversion of NH2CH2COONa and NH(CH2COONa)2 in the deaminated liquid into NH2CH2COOH and monosodium iminodiacetic acid (IDA-Na), and the single-pass yield is greater than 98%. Na in the deaminated liquid is 1.34 g / cm3, and the sodium salt of NH2CH2COONa and NH(CH2COONa)2 is 1.34 g / cm3, and the sodium salt of NH2CH2COONa and NH2CH2COOH ... +The removal rate is greater than 90%, and the concentration of the alkali solution produced by the electrodialysis separation of the device is 8-15%, which can be fully recycled to the alkaline deamination process, thereby replacing the input of most new alkali, and further significantly reducing the amount of sulfuric acid, activated carbon, and by-product sodium sulfate in the subsequent decolorization process. Compared with the existing patented technology, the present invention can reduce the consumption of liquid alkali (based on the production of 1 ton of industrial-grade glycine) by 550-600kg / t, the consumption of sulfuric acid by 680-740kg / t, the consumption of activated carbon by 25-35kg / t, and the output of sodium sulfate (by-product) by 1000-1100kg / t, and the total production cost of glycine by more than 1000 yuan / ton. In the subsequent process production process, since the decolorization solution and the crystallization mother liquor contain only a small amount of impurities such as sodium sulfate, the separation, crystallization and purification of (heat-sensitive materials) glycine and iminodiacetic acid are easier, and the product quality is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0076] Figure 1 This is a synthetic process diagram of glycine (food grade) and IDA (electronic grade) provided in the examples of the present application;

[0077] Figure 2 This is a flow chart for preparing hydrocyanic acid and hydroxyacetonitrile provided in the examples of the present application;

[0078] Figure 3 It is a schematic diagram of the ion membrane separation principle provided in the embodiment of the present application. DETAILED DESCRIPTION

[0079] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0080] In this application, further, in the description of this application, the term "including" means "including but not limited to." The terms first, second, third, etc. are used merely as labels and do not impose numerical requirements or establish a sequence.

[0081] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0082] In the present application, "at least one" means one or more, and "plurality" means two or more. "One or several", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0083] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0084] The technical solution of this application is as follows:

[0085] See also Figure 1 The present invention provides a method for producing glycine and iminodiacetic acid using high-concentration coalbed methane, comprising the following steps:

[0086] S01, amination reaction: hydroxyacetonitrile and concentrated ammonia water are mixed and reacted to obtain an amination reaction solution A;

[0087] S02, alkaline deamination: the amination reaction liquid A is subjected to alkaline deamination reaction with liquid alkali to obtain alkaline hydrolysis liquid B and gaseous ammonia;

[0088] S03, ion membrane separation: using an ion membrane to perform electrodialysis separation on the alkaline solution B to obtain an electrodialysis solution C;

[0089] S04, decolorization: electrodialysis solution C is subjected to decolorization and filtration to obtain decolorized filtrate D;

[0090] S05, concentration and crystallization: the decolorized filtrate D is concentrated and crystallized to obtain a concentrated filtrate E;

[0091] S06, GLY crystallization separation: The concentrated filtrate E is subjected to GLY crystallization separation to obtain a GLY industrial grade filter cake and a primary mother liquor F;

[0092] S07, resin separation: the primary mother liquor F accounting for 10% to 30% of the total mass of the primary mother liquor F is subjected to resin separation to obtain a secondary mother liquor G, which is returned to the concentration and crystallization process for reuse; the resin separation also obtains an extract H;

[0093] S08, GLY refining: purify and refine the GLY industrial-grade filter cake to obtain food-grade glycine;

[0094] S09, IDA refining: The extract H is subjected to the first IDA refining and the second IDA refining to obtain electronic grade iminodiacetic acid.

[0095] In the present application, the alkaline solution (sodium hydroxide) produced by ion membrane separation is directly subjected to alkaline hydrolysis reaction with the amination reaction solution A (aminoacetonitrile, iminodiacetonitrile) to generate basic salts of sodium glycine and sodium iminodiacetic acid, and then electrodialysis separation is performed using an ion membrane separation process to generate glycine and monosodium iminodiacetic acid, and then a small amount of concentrated sulfuric acid and activated carbon are used for acidification and decolorization. This process can successfully realize the conversion of NH2CH2COONa and NH(CH2COONa)2 in the deaminated liquid into NH2CH2COOH and monosodium iminodiacetic acid (IDA-Na), and the single-pass yield is greater than 98%. Na in the deaminated liquid is 1.34 g / cm3, and the sodium salt of NH2CH2COONa and NH(CH2COONa)2 is 1.34 g / cm3, and the sodium salt of NH2CH2COONa and NH2CH2COOH ... + The removal rate is greater than 90%, and the concentration of the alkali solution produced by the electrodialysis separation of the device is 8-15%, which can be fully recycled to the alkaline deamination process, thereby replacing the input of most new alkali, and further significantly reducing the amount of sulfuric acid, activated carbon, and by-product sodium sulfate in the subsequent decolorization process. Compared with the existing patented technology, the present invention can reduce the consumption of liquid alkali (based on the production of 1 ton of industrial-grade glycine) by 550-600kg / t, the consumption of sulfuric acid by 680-740kg / t, the consumption of activated carbon by 25-35kg / t, and the output of sodium sulfate (by-product) by 1000-1100kg / t, and the total production cost of glycine by more than 1000 yuan / ton. In the subsequent process production process, since the decolorization solution and the crystallization mother liquor contain only a small amount of impurities such as sodium sulfate, the separation, crystallization and purification of (heat-sensitive materials) glycine and iminodiacetic acid are easier, and the product quality is better.

[0096] In the S01:

[0097] In some embodiments, the mass concentration of hydroxyacetonitrile is 49% to 51%, for example, 49%, 49.5%, 50%, 50.5%, 51%, etc.

[0098] In some embodiments, the concentration of concentrated ammonia water is 20% to 35%, for example, it can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, etc.

[0099] In some embodiments, the molar ratio of hydroxyacetonitrile to concentrated aqueous ammonia is 1:2.1 to 1:4.5, for example, 1:2.1, 1:2.5, 1:2.8, 1:3, 1:3.2, 1:3.5, 1:3.8, 1:4, 1:4.1, 1:4.2, 1:4.5, etc.

[0100] In some embodiments, hydroxyacetonitrile and concentrated ammonia water are mixed and preheated to temperature T1, and reacted at temperature T2 and pressure P1 for a reaction time of t1 to obtain an amination reaction solution A.

[0101] Further, T1 is 40°C to 60°C, for example, 40°C, 42°C, 45°C, 48°C, 50°C, 52°C, 55°C, 58°C, 60°C;

[0102] T2 is 55°C to 110°C, for example, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, etc.

[0103] P1 is 0.5 MPa to 2.5 MPa, for example, it can be 0.5 MPa, 0.8 MPa, 1 MPa, 1.2 MPa, 1.5 MPa, 1.8 MPa, 2 MPa, 2.2 MPa, 2.5 MPa, etc.

[0104] t1 is 3 min to 10 min, for example, it can be 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min.

[0105] It can be understood that the entire amination reaction system is closed, safe, fully automatic and fully continuous.

[0106] Further, hydroxyacetonitrile and concentrated ammonia water are continuously reacted in an ammonia reactor.

[0107] See also Figure 2 In some embodiments, obtaining hydroxyacetonitrile comprises the following steps:

[0108] S011, high concentration coalbed methane is removed by PSA impurity removal device to obtain methane;

[0109] S012, methane is mixed with ammonia and air to react and obtain hydrocyanic acid;

[0110] S013, Hydrocyanic acid reacts with formaldehyde to obtain hydroxyacetonitrile.

[0111] In said S011:

[0112] In some embodiments, the high-concentration coalbed methane, by mass percentage, includes 90% to 97% methane, 3% to 8% N2+O2, and the remainder is ethane, propane, butane, H2S and CO2.

[0113] It can be understood that the content of each gas in high-concentration coalbed methane is expressed in mass percentage.

[0114] It can be understood that the PSA pressure swing adsorption device is filled with adsorbents such as activated carbon and 13X molecular sieve, and methane is obtained after deep desulfurization and impurity removal by the PSA impurity removal device.

[0115] In some embodiments, the high-concentration coalbed methane is passed through a PSA impurity removal device and the decomposed gas is incinerated in a tail boiler.

[0116] Furthermore, the analyzed gas includes, by mass percentage, 88% to 96% methane, 4% to 12% N2+O2, and the remainder is ethane, propane, butane, H2S and CO2.

[0117] In said S012:

[0118] In some embodiments, methane is preheated to a temperature of T5, mixed evenly with pre-mixed ammonia and air at a temperature of T6, and then enters a fixed bed reactor to undergo methane ammonia oxidation reaction at a high temperature of T7 with pressure P3 under the action of a platinum mesh catalyst to obtain a synthetic reaction gas A, and then the synthetic gas A is sent to a pickling tower for residual ammonia absorption and gas cooling to obtain a synthetic gas B with a mass content of hydrocyanic acid of M4.

[0119] Furthermore, T5 is 50°C to 80°C, for example, it can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc.

[0120] T6 is 50°C to 80°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc.

[0121] P3 is 0.07 MPa to 0.15 MPa, for example, it can be 0.07 MPa, 0.09 MPa, 0.1 MPa, 0.12 MPa, 0.13 MPa, 0.15 MPa, etc.

[0122] T7 is 1000°C to 1200°C, for example, it can be 1020°C, 1030°C, 1050°C, 1080°C, 1100°C, 1120°C, 1150°C, 1160°C, 1180°C, 1200°C, etc.

[0123] M4 is 8% to 12%, for example, 8%, 9%, 10%, 10.5%, 11%, 12%, etc.

[0124] Furthermore, the synthesis reaction gas A includes HCN, NH3, CH4, N2, CO, CO2, O2, and H2O.

[0125] Further, the synthesis gas B includes HCN, H2SO4, CH4, N2, CO, CO2, and O2.

[0126] In some embodiments, the molar ratio of methane, ammonia and air is 1:1.05-1.2:5.5-7.0, for example, it can be 1:1.05:5.5, 1:1.1:6, 1:1.15:6.5, 1:1.2:6.8, 1:1.2:7, etc.

[0127] In the S013:

[0128] In some embodiments, the mass concentration of formaldehyde is 36.5% to 37%, for example, 36.5%, 36.6%, 36.7%, 36.8%, 36.9%, or 37%.

[0129] In some embodiments, the molar ratio of hydrocyanic acid to formaldehyde is 1:1.01-1.2, for example, 1:1.01, 1:1.02, 1:1.05, 1:1.08, 1:1.1, 1:1.12, 1:1.15, 1:1.18, 1:2, etc.

[0130] In some embodiments, the mass concentration of hydroxyacetonitrile is 49% to 51%, for example, 49%, 49.5%, 50%, 50.5%, 51%, etc.

[0131] The pH of hydroxyacetonitrile is 1.5 to 3, for example, 1.5, 1.6, 1.8, 2, 2.2, 2.5, 2.6, 2.8, 3, etc.

[0132] It is understood that the pH of hydroxyacetonitrile is adjusted to 1.5 to 3 with concentrated sulfuric acid.

[0133] In the present application, a ternary material component of high-concentration coalbed methane (methane content 90-97%), ammonia produced by vaporization of liquid ammonia, and air is used, and under the catalysis of high-purity platinum mesh, at 1000-1200°C and pressure 0.07-0.15MPa, direct mixed reaction is performed to prepare hydrocyanic acid, and HCN synthesis gas with a content of 8-12% is obtained, and a large amount of reaction heat (by-product steam) is recovered. The present invention simplifies and shortens the process flow of the existing low-concentration coalbed methane preparation HCN route, and by optimizing and increasing the reaction pressure and strengthening the density of the mixed reaction gas, the production capacity of the reactor of the same specification is increased by 20-30%, and the HCN reaction yield is increased from 61-62% to 63-65%, and the number of process equipment is reduced, a large amount of engineering equipment investment is saved, the energy consumption of the device and environmental pollution are reduced, and the manufacturing cost of each ton of HCN is reduced by 400-500 yuan / ton.

[0134] In the S02:

[0135] In some embodiments, the amination reaction solution A includes, by mass percentage, 15% to 22% NH2CH2CN, 1.0% to 2.5% NH(CH2CN)2, 3% to 8% NH3, trace amounts of HOCH2CN and nitrile polymers, and the remainder is water.

[0136] In some embodiments, the liquid alkali is a sodium hydroxide solution, and the concentration of sodium hydroxide is 30% to 42%, for example, 30%, 32%, 35%, 36%, 38%, 40%, 42%, etc.

[0137] Furthermore, the molar ratio of NH2CH2CN to NaOH is 1:1.1 to 1:1.5, for example, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, etc.

[0138] In some embodiments, the amination reaction liquid A is mixed with liquid alkali and subjected to a hydrolysis deamination reaction at a pressure P2 and a temperature T3.

[0139] Furthermore, P2 is -95Kpa to -30Kpa, for example, it can be -95Kpa, -90Kpa, -85Kpa, -80Kpa, -70Kpa, -60Kpa, -50Kpa, -40Kpa, -30Kpa, etc.

[0140] T3 is 50°C to 110°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, etc.

[0141] Furthermore, the amination reaction liquid A is mixed with liquid alkali and continuously enters the alkaline deamination reactor at pressure P2 and temperature T3 for alkaline deamination reaction, and the residual ammonia remaining in the reaction liquid is removed by a deamination tower to obtain alkaline hydrolysis liquid B.

[0142] Furthermore, the removed gaseous ammonia is added with water to recover 20% to 35% concentrated ammonia water, which is returned to step S01 for reuse.

[0143] In said S03:

[0144] See also Figure 3 In some embodiments, the alkaline hydrolysis solution B includes, by mass percentage, 15% to 30% NH2CH2COONa, 1% to 4% IDA-2Na, 1% to 3% NaOH, trace amounts of other impurities, and the remainder is water.

[0145] Furthermore, trace amounts of other impurities include sodium glycolate and sodium salt of nitrile polymer.

[0146] It can be understood that trace amount means a mass content of ≤0.1%.

[0147] Further, the alkaline hydrolyzate B is separated by an ion membrane, and an electrodialysis solution C is generated in a salt chamber. The electrodialysis solution C includes, by mass percentage, 12% to 25% GLY, 1% to 3% IDA-Na, a trace amount of water-soluble sodium salt impurities, and the balance is water;

[0148] Further, NaOH and H2O are generated in the alkali chamber.

[0149] Furthermore, the NaOH and H2O generated in the alkali chamber are returned to SO2 and reused as alkali solution.

[0150] Furthermore, trace water-soluble sodium salt impurities include sodium glycolate and sodium salt of nitrile polymer.

[0151] It can be understood that trace amount means a mass content of ≤0.1%.

[0152] It will be appreciated that the ion membrane is an ion exchange membrane.

[0153] In said S04:

[0154] In some embodiments, the electrodialysis solution C is subjected to pH adjustment to obtain a feed solution at a temperature T4, and activated carbon is used to remove colored impurities in the feed solution, and then the decolorized filtrate D is obtained after filtration through a membrane core.

[0155] It can be understood that the material of the membrane core is polypropylene and polytetrafluoroethylene.

[0156] Furthermore, T4 is 50°C to 90°C, for example, it can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, etc.

[0157] Further, the pH value is adjusted to 4-7 with concentrated sulfuric acid, for example, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, etc.

[0158] Furthermore, the concentration of concentrated sulfuric acid is 93% to 98%, for example, 93%, 94%, 95%, 96%, 97%, 98%, etc.

[0159] Furthermore, the activated carbon accounts for 1‰ to 3‰ of the total mass of the feed liquid, for example, it can be 1‰, 1.2‰, 1.5‰, 1.8‰, 2‰, 2.2‰, 2.5‰, 2.8‰, 3‰, etc.

[0160] Furthermore, the colored impurities include nitrile char and / or polypeptide polymers.

[0161] Furthermore, the decolorized filtrate D, by mass percentage, includes 15% to 20% GLY, 2% to 4% IDA-Na, 1% to 5% Na2SO4, a trace amount of water-soluble sodium salt impurities, and the balance is water.

[0162] Furthermore, trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides.

[0163] It can be understood that trace amount means a mass content of ≤0.1%.

[0164] It is understood that the water-soluble sodium salts containing nitrile groups and polypeptides are decolorized and not adsorbed.

[0165] It can be understood that, compared with the existing domestic technology, the decolorization process of the present application only requires a small amount of concentrated sulfuric acid for adjustment and only a small amount of decolorizing agent activated carbon consumption to achieve the decolorization index requirements.

[0166] In said S05:

[0167] In some embodiments, the decolorized filtrate D enters an evaporation concentration device to evaporate excess water and remove 40% to 90% by mass of Na2SO4 to obtain a concentrated filtrate E.

[0168] Furthermore, the removal rate of Na2SO4 is 40% to 90%, for example, it can be 40, 45, 50, 55, 60, 65, 70%, 75%, 80%, 82%, 85%, 88%, 90%, etc.

[0169] Furthermore, the concentrated filtrate E comprises, by mass percentage, 25% to 35% GLY, 2% to 8% IDA-Na, 5% to 8% Na2SO4, a trace amount of water-soluble sodium salt impurities, and the remainder is water.

[0170] Furthermore, trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides.

[0171] It can be understood that trace amount means a mass content of ≤0.1%.

[0172] Furthermore, concentrated crystallization also obtains sodium sulfate as a by-product.

[0173] It can be understood that the concentrated solution after concentrated crystallization is centrifuged to obtain sodium sulfate as a by-product.

[0174] In said S06:

[0175] In some embodiments, the weight content of GLY in the GLY industrial grade filter cake is 98%.

[0176] In some embodiments, the primary mother liquor F comprises, by mass percentage, 18% to 25% GLY, 4% to 10% IDA-Na, 6% to 10% Na2SO4, a trace amount of water-soluble sodium salt impurities, and the remainder is water.

[0177] Furthermore, trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides.

[0178] It can be understood that trace amount means a mass content of ≤0.1%.

[0179] In some embodiments, the primary mother liquor F accounting for 70% to 90% of the total mass of the primary mother liquor F is returned to the concentration and crystallization step for reuse.

[0180] In said S07:

[0181] It can be understood that the primary mother liquor F accounting for 10% to 30% of the total mass of the primary mother liquor F enters the resin separation device, and the IDA-Na, sodium sulfate and other sodium salt impurities (trace water-soluble hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides) in the primary mother liquor F are extracted using the chromatographic separation principle.

[0182] In some embodiments, the secondary mother liquor G includes, by mass percentage, 6% to 15% GLY, 0.1% to 1% IDA-Na, a trace amount of sodium sulfate, and the remainder is water.

[0183] It can be understood that trace amount means a mass content of ≤0.1%.

[0184] In some embodiments, the extract H comprises, by mass percentage, 6% to 12% GLY, 1% to 5% Na2SO4, a trace amount of water-soluble sodium salt impurities, and the remainder is water.

[0185] Furthermore, trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides.

[0186] It can be understood that trace amount means a mass content of ≤0.1%.

[0187] Further, the extract H is used to produce electronic grade IDA.

[0188] It can be understood that, compared with the prior art, the extraction rate of IDA-Na and other sodium salt impurities in the primary mother liquor F is ≥95%, and the GLY product loss rate is ≤6%, which can significantly improve the product yield, reduce raw material consumption, reduce costs, and reduce waste liquid discharge; the glycine production cost is reduced by about 500 yuan / ton compared with the current process route, and the entire resin separation system is closed, safe, fully automatic, and fully continuous.

[0189] In said S08:

[0190] In some embodiments, the GLY industrial-grade filter cake is sequentially subjected to GLY refining, crystallization separation, drying and airing to obtain food-grade glycine.

[0191] In said S09:

[0192] In some embodiments, the first IDA refining comprises: adjusting the pH value of the extract H to 1.9-2.1, for example, 1.9, 1.95, 1.98, 2.0, 2.1, etc., with sulfuric acid at room temperature and pressure; then evaporating and concentrating, desalting, cooling and crystallizing, centrifuging, and drying to obtain industrial-grade iminodiacetic acid.

[0193] Furthermore, 30% to 50% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining is sent to an incinerator as waste liquid I for harmless incineration treatment.

[0194] Furthermore, the waste liquid I comprises, by mass percentage, 0.5% to 5% IDA-Na, 3% to 10% Na2SO4, 5% to 10% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water.

[0195] Furthermore, 50% to 70% by weight of the IDA circulating crystallization mother liquor produced by the first IDA purification is returned to the concentration crystallization process of step S05.

[0196] Furthermore, the IDA circulating crystallization mother liquor includes 0.5% to 5% IDA-Na, 3% to 10% Na2SO4, 5% to 10% glycolic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water.

[0197] In some embodiments, the second IDA refining includes heating and dissolving industrial-grade iminodiacetic acid and desalted water, and then performing high-efficiency decolorization, removing heavy metal impurities with a complexing agent, fine filtration, cooling crystallization, centrifugal separation, vacuum drying, and screening to obtain electronic-grade iminodiacetic acid.

[0198] Example 1

[0199] Preparation of hydroxyacetonitrile:

[0200] S011, high concentration coalbed methane is removed by PSA impurity removal device to obtain methane;

[0201] S012, methane is preheated to a temperature of T5, mixed evenly with ammonia and air at a premixed temperature of T6, and then enters a fixed bed reactor, where a methane ammoxidation reaction is carried out at a high temperature of T7 with a pressure of P3 under the action of a platinum mesh catalyst to obtain a synthetic reaction gas A, and then the synthetic gas A is sent to an acid washing tower for residual ammonia absorption and gas cooling to obtain a synthetic gas B with a mass content of hydrocyanic acid of M4;

[0202] Among them, T5 is 50°C, T6 is 50°C, P3 is 0.07MPa, T7 is 1000°C, M4 is 8%; the molar ratio of methane, ammonia and air is 1:1.05:5.5.

[0203] S013, hydrocyanic acid reacts with formaldehyde to obtain hydroxyacetonitrile;

[0204] Among them, the mass concentration of formaldehyde is 36.5%, and the molar ratio of hydrocyanic acid to formaldehyde is 1:1.01;

[0205] The concentration of hydroxyacetonitrile was 49%; the pH was 1.5.

[0206] Example 2

[0207] Preparation of hydroxyacetonitrile:

[0208] S011, high concentration coalbed methane is removed by PSA impurity removal device to obtain methane;

[0209] S012, methane is preheated to a temperature of T5, mixed evenly with ammonia and air at a premixed temperature of T6, and then enters a fixed bed reactor, where a methane ammoxidation reaction is carried out at a high temperature of T7 with a pressure of P3 under the action of a platinum mesh catalyst to obtain a synthetic reaction gas A, and then the synthetic gas A is sent to an acid washing tower for residual ammonia absorption and gas cooling to obtain a synthetic gas B with a mass content of hydrocyanic acid of M4;

[0210] Among them, T5 is 65°C, T6 is 65°C, P3 is 0.11Mpa, T7 is 1100°C, M4 is 10%; the molar ratio of methane, ammonia and air is 1:1.12:6.2.

[0211] S013, hydrocyanic acid reacts with formaldehyde to obtain hydroxyacetonitrile;

[0212] Among them, the mass concentration of formaldehyde is 36.8%, and the molar ratio of hydrocyanic acid to formaldehyde is 1:1.1;

[0213] The concentration of hydroxyacetonitrile was 50%; the pH was 2.3.

[0214] Example 3

[0215] Preparation of hydroxyacetonitrile:

[0216] S011, high concentration coalbed methane is removed by PSA impurity removal device to obtain methane;

[0217] S012, methane is preheated to a temperature of T5, mixed evenly with ammonia and air at a premixed temperature of T6, and then enters a fixed bed reactor, where a methane ammoxidation reaction is carried out at a high temperature of T7 with a pressure of P3 under the action of a platinum mesh catalyst to obtain a synthetic reaction gas A, and then the synthetic gas A is sent to an acid washing tower for residual ammonia absorption and gas cooling to obtain a synthetic gas B with a mass content of hydrocyanic acid of M4;

[0218] Among them, T5 is 80°C, T6 is 80°C, P3 is 0.15Mpa, T7 is 1200°C, M4 is 12%; the molar ratio of methane, ammonia and air is 1:1.2:7.0.

[0219] S013, hydrocyanic acid reacts with formaldehyde to obtain hydroxyacetonitrile;

[0220] The mass concentration of formaldehyde is 37%, and the molar ratio of hydrocyanic acid to formaldehyde is 1:1.2;

[0221] The concentration of hydroxyacetonitrile was 51%; the pH was 3.

[0222] Example 4

[0223] Based on Example 2, a method for producing glycine and iminodiacetic acid using high-concentration coalbed methane is provided, comprising the following steps:

[0224] S01, amination reaction: hydroxyacetonitrile and concentrated ammonia water are mixed and reacted to obtain an amination reaction solution A;

[0225] Wherein, hydroxyacetonitrile is prepared as in Example 2, the concentration of hydroxyacetonitrile is 50%, the pH is 2.3, the concentration of concentrated ammonia water is 20%, and the molar ratio of hydroxyacetonitrile to concentrated ammonia water is 1:2.1; hydroxyacetonitrile and concentrated ammonia water are continuously reacted in an ammonia reactor, hydroxyacetonitrile and concentrated ammonia water are mixed and preheated to a temperature T1, reacted at a temperature T2 and a pressure P1, and the reaction time is t1, to obtain an ammonia reaction liquid A;

[0226] T1 is 40℃, T2 is 55℃, P1 is 0.5Mpa, and t1 is 10min;

[0227] S02, alkaline deamination: the amination reaction liquid A is subjected to alkaline deamination reaction with liquid alkali to obtain alkaline hydrolysis liquid B and gaseous ammonia;

[0228] Amination reaction liquid A, by mass percentage, includes 15% NH2CH2CN, 1.0% NH(CH2CN)2, 3% NH3, trace amounts of HOCH2CN and nitrile polymers, and the balance is water;

[0229] The liquid alkali is a sodium hydroxide solution, and the concentration of sodium hydroxide is 30%;

[0230] The molar ratio of NH2CH2CN to NaOH is 1:1.1;

[0231] After the ammoniation reaction liquid A is mixed with liquid alkali, it continuously enters the alkaline deamination reactor at pressure P2 and temperature T3 to carry out alkaline deamination reaction. The residual ammonia in the reaction liquid is removed by a deamination tower to remove gaseous ammonia to obtain alkaline hydrolysis liquid B, wherein P2 is -95Kpa, T3 is 50°C, and the removed gaseous ammonia is added with water to recover 20% concentrated ammonia water, which is returned to step S01 for reuse;

[0232] S03, ion membrane separation: using an ion membrane to perform electrodialysis separation on the alkaline solution B to obtain an electrodialysis solution C;

[0233] Alkaline hydrolysis solution B, by mass percentage, includes 22% NH2CH2COONa, 2.5% IDA-2Na, 2% NaOH, trace amounts of other impurities, and the balance is water, wherein trace amounts of other impurities include sodium hydroxyacetate and sodium salts of nitrile polymers, and trace amounts refer to a mass content of ≤0.1%; alkaline hydrolysis solution B is separated by an ion membrane, and an electrodialysis solution C is generated in a salt chamber, and the electrodialysis solution, by mass percentage, includes 18% GLY, 1.5% IDA-Na, trace amounts of water-soluble sodium salt impurities, and the balance is water, and trace amounts of water-soluble sodium salt impurities include sodium hydroxyacetate and sodium salts of nitrile polymers, and trace amounts refer to a mass content of ≤0.1%; NaOH and H2O generated in the alkali chamber are returned to S02 and reused as alkali solution;

[0234] S04, decolorization: electrodialysis solution C is subjected to decolorization and filtration to obtain decolorized filtrate D;

[0235] Electrodialysis solution C is subjected to pH adjustment at temperature T4, and the activated carbon removes colored impurities in the feed solution, and then the decolorized filtrate D is obtained after filtration through a membrane core;

[0236] T4 is 50℃, the pH is adjusted to 4 with 93% concentrated sulfuric acid, and the activated carbon accounts for 1‰ of the total mass of the feed liquid;

[0237] Colored impurities include nitrile char and / or peptide polymers;

[0238] The decolorized filtrate D includes 15% by mass of GLY, 2% by mass of IDA-Na, 1% by mass of Na2SO4 and trace amounts of water-soluble sodium salt impurities, and the balance is water. The trace amounts of water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The trace amounts refer to a mass content of ≤0.1%;

[0239] S05, concentration and crystallization: the decolorized filtrate D is concentrated and crystallized to obtain a concentrated filtrate E;

[0240] The decolorized filtrate D enters the evaporation concentration device to evaporate excess water and remove Na2SO4, thereby obtaining a concentrated filtrate E with a Na2SO4 removal rate of 40%. The concentrated filtrate E, by mass percentage, includes 25% GLY, 2% IDA-Na, 5% Na2SO4, trace water-soluble sodium salt impurities, and the remainder is water. The trace water-soluble sodium salt impurities include hydroxyacetic acid and water-soluble sodium salts containing nitrile groups and polypeptides. Concentrated crystallization also obtains sodium sulfate as a by-product.

[0241] S06, GLY crystallization separation: The concentrated filtrate E is subjected to GLY crystallization separation to obtain a GLY industrial grade filter cake and a primary mother liquor F;

[0242] The weight content of GLY in the GLY industrial grade filter cake is 98%;

[0243] The primary mother liquor F, calculated by mass percentage, comprises 18% GLY, 4% IDA-Na, 6% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The trace amount means that the mass content is ≤0.1%;

[0244] The primary mother liquor F accounting for 70% of the total mass of the primary mother liquor F is returned to the concentration and crystallization step for reuse.

[0245] S07, resin separation: the primary mother liquor F accounting for 30% of the total mass of the primary mother liquor F is subjected to resin separation to obtain a secondary mother liquor G, which is returned to the concentration and crystallization process for reuse; the resin separation also obtains an extract H;

[0246] The secondary mother liquor G, calculated by mass percentage, comprises 6% GLY, 0.1% IDA-Na, an aqueous solution of trace sodium sulfate, wherein trace refers to a mass content of ≤0.1%, and the remainder is water;

[0247] Extract H, by mass percentage, includes 6% GLY, 1% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include hydroxyacetic acid and water-soluble sodium salts containing nitrile groups and polypeptides; Extract H is used to produce electronic grade IDA.

[0248] S08, GLY refining: purify and refine the GLY industrial-grade filter cake to obtain food-grade glycine;

[0249] GLY industrial-grade filter cake is successively subjected to GLY refining, crystallization separation, drying and airing to obtain food-grade glycine;

[0250] S09, IDA refining: the extract H is subjected to a first IDA refining and a second IDA refining to obtain electronic grade iminodiacetic acid;

[0251] The first IDA refining comprises: adjusting the pH value of the extract H to 1.9 with sulfuric acid at room temperature and pressure, and then evaporating and concentrating, desalting, cooling and crystallizing, centrifuging and drying to obtain industrial-grade iminodiacetic acid; 30% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining is sent to an incinerator as waste liquid I for harmless incineration treatment; the waste liquid I, by mass percentage, comprises 0.5% IDA-Na, 3% Na2SO4, 5% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water; the first 70% by weight of the IDA circulating crystallization mother liquor produced by IDA refining is returned to the concentrated crystallization process of step S05; the IDA circulating crystallization mother liquor includes 0.5% IDA-Na, 3% Na2SO4, 5% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water; the second IDA refining includes heating and dissolving industrial-grade iminodiacetic acid and desalted water, and then undergoing high-efficiency decolorization, complexing agent removal of heavy metal impurities, fine filtration, cooling crystallization, centrifugal separation, vacuum drying, and screening to obtain electronic-grade iminodiacetic acid.

[0252] Example 5

[0253] Based on Example 2, a method for producing glycine and iminodiacetic acid using high-concentration coalbed methane is provided, comprising the following steps:

[0254] S01, amination reaction: hydroxyacetonitrile and concentrated ammonia water are mixed and reacted to obtain an amination reaction solution A;

[0255] Wherein, hydroxyacetonitrile is prepared as in Example 2, the concentration of hydroxyacetonitrile is 50%, the pH is 2.3, the concentration of concentrated ammonia water is 28%, and the molar ratio of hydroxyacetonitrile to concentrated ammonia water is 1:3.3; hydroxyacetonitrile and concentrated ammonia water are continuously reacted in an ammonia reactor, hydroxyacetonitrile and concentrated ammonia water are mixed and preheated to a temperature T1, reacted at a temperature T2 and a pressure P1, and the reaction time is t1, to obtain an ammonia reaction liquid A;

[0256] T1 is 50℃, T2 is 85℃, P1 is 1.5Mpa, and t1 is 6min;

[0257] S02, alkaline deamination: the amination reaction liquid A is subjected to alkaline deamination reaction with liquid alkali to obtain alkaline hydrolysis liquid B and gaseous ammonia;

[0258] The amination reaction solution A includes 18% NH2CH2CN, 1.8% NH(CH2CN)2, 5.5% NH3, trace amounts of HOCH2CN and nitrile polymers, and the remainder is water;

[0259] The liquid alkali is a sodium hydroxide solution, and the concentration of sodium hydroxide is 36%;

[0260] The molar ratio of NH2CH2CN to NaOH is 1:1.3;

[0261] After the ammoniation reaction liquid A is mixed with liquid alkali, it continuously enters the alkaline deamination reactor at pressure P2 and temperature T3 to carry out alkaline deamination reaction. The residual ammonia in the reaction liquid is removed by a deamination tower to remove gaseous ammonia to obtain alkaline hydrolysis liquid B, wherein P2 is -62Kpa, T3 is 80°C, and the removed gaseous ammonia is added with water to recover 28% concentrated ammonia water, which is returned to step S01 for reuse;

[0262] S03, ion membrane separation: using an ion membrane to perform electrodialysis separation on the alkaline solution B to obtain an electrodialysis solution C;

[0263] Alkaline hydrolysis solution B, by mass percentage, includes 15% NH2CH2COONa, 1% IDA-2Na, 1% NaOH, trace amounts of other impurities, and the balance is water, wherein trace amounts of other impurities include sodium hydroxyacetate and sodium salts of nitrile polymers, and trace amounts refer to a mass content of ≤0.1%; alkaline hydrolysis solution B is separated by an ion membrane, and an electrodialysis solution C is generated in a salt chamber, and the electrodialysis solution C, by mass percentage, includes 12% GLY, 1% IDA-Na, trace amounts of water-soluble sodium salt impurities, and the balance is water, wherein trace amounts of water-soluble sodium salt impurities include sodium hydroxyacetate and sodium salts of nitrile polymers, and trace amounts refer to a mass content of ≤0.1%; NaOH and H2O generated in the alkali chamber are returned to S02 and reused as alkali solution;

[0264] S04, decolorization: electrodialysis solution C is subjected to decolorization and filtration to obtain decolorized filtrate D;

[0265] Electrodialysis solution C is subjected to pH adjustment at temperature T4, and the activated carbon removes colored impurities in the feed solution, and then the decolorized filtrate D is obtained after filtration through a membrane core;

[0266] T4 is 70℃, the pH is adjusted to 5.5 with 95% concentrated sulfuric acid, and the activated carbon accounts for 2‰ of the total mass of the feed liquid;

[0267] Colored impurities include nitrile char and / or peptide polymers;

[0268] The decolorized filtrate D includes 17% by mass of GLY, 3% by mass of IDA-Na, 3% by mass of Na2SO4 and trace amounts of water-soluble sodium salt impurities, and the balance is water. The trace amounts of water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The trace amounts refer to a mass content of ≤0.1%;

[0269] S05, concentration and crystallization: the decolorized filtrate D is concentrated and crystallized to obtain a concentrated filtrate E;

[0270] The decolorized filtrate D enters the evaporation concentration device to evaporate excess water and remove Na2SO4, thereby obtaining a concentrated filtrate E with a Na2SO4 removal rate of 80%. The concentrated filtrate E, by mass percentage, includes 30% GLY, 5% IDA-Na, 6.5% Na2SO4, trace water-soluble sodium salt impurities, and the remainder is water. The trace water-soluble sodium salt impurities include hydroxyacetic acid and water-soluble sodium salts containing nitrile groups and polypeptides. Concentrated crystallization also obtains sodium sulfate as a by-product.

[0271] S06, GLY crystallization separation: The concentrated filtrate E is subjected to GLY crystallization separation to obtain a GLY industrial grade filter cake and a primary mother liquor F;

[0272] The weight content of GLY in the GLY industrial grade filter cake is 98%;

[0273] The primary mother liquor F, by mass percentage, comprises 22% GLY, 7% IDA-Na, 8% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The trace amount means that the mass content is ≤0.1%;

[0274] The primary mother liquor F accounting for 80% of the total mass of the primary mother liquor F is returned to the concentration and crystallization step for reuse.

[0275] S07, resin separation: the primary mother liquor F accounting for 20% of the total mass of the primary mother liquor F is subjected to resin separation to obtain a secondary mother liquor G, which is returned to the concentration and crystallization process for reuse; the resin separation also obtains an extract H;

[0276] The secondary mother liquor G, calculated by mass percentage, comprises 11% GLY, 0.5% IDA-Na, an aqueous solution of trace sodium sulfate, wherein trace refers to a mass content of ≤0.1%, and the remainder is water;

[0277] Extract H, by mass percentage, includes 9% GLY, 3% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include hydroxyacetic acid and water-soluble sodium salts containing nitrile groups and polypeptides; Extract H is used to produce electronic grade IDA.

[0278] S08, GLY refining: purify and refine the GLY industrial-grade filter cake to obtain food-grade glycine;

[0279] GLY industrial-grade filter cake is successively subjected to GLY refining, crystallization separation, drying and airing to obtain food-grade glycine;

[0280] S09, IDA refining: the extract H is subjected to a first IDA refining and a second IDA refining to obtain electronic grade iminodiacetic acid;

[0281] The first IDA refining comprises: adjusting the pH value of the extract H to 2 with sulfuric acid at room temperature and pressure, and then evaporating and concentrating, desalting, cooling and crystallizing, centrifuging and drying to obtain industrial-grade iminodiacetic acid; 40% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining is sent to an incinerator as waste liquid I for harmless incineration treatment; the waste liquid I, by mass percentage, comprises 2.5% IDA-Na, 6% Na2SO4, 7% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water; 60% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining is returned to the concentration and crystallization process of step S05; the IDA circulating crystallization mother liquor comprises 2.5% IDA-Na, 6% Na2SO4, 7% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides. Na2SO4, 7% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water; the second IDA refining includes heating and dissolving industrial-grade iminodiacetic acid with desalted water, and then undergoing high-efficiency decolorization, complexing agent removal of heavy metal impurities, fine filtration, cooling crystallization, centrifugal separation, vacuum drying, and screening to obtain electronic-grade iminodiacetic acid.

[0282] Example 6

[0283] Based on Example 2, a method for producing glycine and iminodiacetic acid using high-concentration coalbed methane is provided, comprising the following steps:

[0284] S01, amination reaction: hydroxyacetonitrile and concentrated ammonia water are mixed and reacted to obtain an amination reaction solution A;

[0285] Wherein, hydroxyacetonitrile is prepared as in Example 2, the concentration of hydroxyacetonitrile is 50%, the pH is 2.3, the concentration of concentrated ammonia water is 35%, and the molar ratio of hydroxyacetonitrile to concentrated ammonia water is 1:4.5; hydroxyacetonitrile and concentrated ammonia water are continuously reacted in an ammonia reactor, hydroxyacetonitrile and concentrated ammonia water are mixed and preheated to a temperature T1, reacted at a temperature T2 and a pressure P1, and the reaction time is t1, to obtain an ammonia reaction liquid A;

[0286] T1 is 60℃, T2 is 110℃, P1 is 2.5Mpa, and t1 is 3min;

[0287] S02, alkaline deamination: the amination reaction liquid A is subjected to alkaline deamination reaction with liquid alkali to obtain alkaline hydrolysis liquid B and gaseous ammonia;

[0288] The amination reaction solution A includes 22% NH2CH2CN, 2.5% NH(CH2CN)2, 8% NH3, trace amounts of HOCH2CN and nitrile polymers, and the remainder is water;

[0289] The liquid caustic soda is a sodium hydroxide solution, and the concentration of sodium hydroxide is 42%;

[0290] The molar ratio of NH2CH2CN to NaOH is 1:1.5;

[0291] After the ammoniation reaction liquid A is mixed with liquid alkali, it continuously enters the alkaline deamination reactor at pressure P2 and temperature T3 to carry out alkaline deamination reaction. The residual ammonia in the reaction liquid is removed by a deamination tower to remove gaseous ammonia to obtain alkaline hydrolysis liquid B, wherein P2 is -30Kpa, T3 is 110°C, and the removed gaseous ammonia is added with water to recover 35% concentrated ammonia water, which is returned to step S01 for reuse;

[0292] S03, ion membrane separation: using an ion membrane to perform electrodialysis separation on the alkaline solution B to obtain an electrodialysis solution C;

[0293] The alkaline hydrolysis solution B includes 30% NH2CH2COONa, 4% IDA-2Na, 3% NaOH, trace amounts of other impurities, and the balance is water, wherein trace amounts of other impurities include sodium hydroxyacetate and sodium salts of nitrile polymers, and trace amounts refer to a mass content of ≤0.1%; the alkaline hydrolysis solution B is separated by an ion membrane, and an electrodialysis solution C is generated in a salt chamber, and the electrodialysis solution C includes 25% GLY, 3% IDA-Na, trace amounts of water-soluble sodium salt impurities, and the balance is water, wherein trace amounts of water-soluble sodium salt impurities include sodium hydroxyacetate and sodium salts of nitrile polymers, and trace amounts refer to a mass content of ≤0.1%; the NaOH and H2O generated in the alkali chamber are returned to S02 and reused as alkali solution;

[0294] S04, decolorization: electrodialysis solution C is subjected to decolorization and filtration to obtain decolorized filtrate D;

[0295] Electrodialysis solution C is subjected to pH adjustment at temperature T4, and the activated carbon removes colored impurities in the feed solution, and then the decolorized filtrate D is obtained after filtration through a membrane core;

[0296] T4 is 50℃~90℃, and the pH value is adjusted to 4~7 with 93%~98% concentrated sulfuric acid, and the activated carbon accounts for 1‰~3‰ of the total mass of the feed liquid;

[0297] Colored impurities include nitrile char and / or peptide polymers;

[0298] The decolorized filtrate D includes 20% by mass of GLY, 4% by mass of IDA-Na, 5% by mass of Na2SO4 and trace amounts of water-soluble sodium salt impurities, and the balance is water. The trace amounts of water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The trace amounts refer to a mass content of ≤0.1%;

[0299] S05, concentration and crystallization: the decolorized filtrate D is concentrated and crystallized to obtain a concentrated filtrate E;

[0300] The decolorized filtrate D enters the evaporation concentration device to evaporate excess water and remove Na2SO4, thereby obtaining a concentrated filtrate E with a Na2SO4 removal rate of 90%. The concentrated filtrate E, by mass percentage, includes 35% GLY, 8% IDA-Na, 8% Na2SO4, trace water-soluble sodium salt impurities, and the remainder is water. The trace water-soluble sodium salt impurities include hydroxyacetic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The concentrated crystallization also obtains sodium sulfate as a by-product.

[0301] S06, GLY crystallization separation: The concentrated filtrate E is subjected to GLY crystallization separation to obtain a GLY industrial grade filter cake and a primary mother liquor F;

[0302] The weight content of GLY in the GLY industrial grade filter cake is 98%;

[0303] The primary mother liquor F, calculated by mass percentage, comprises 25% GLY, 10% IDA-Na, 10% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The trace amount means that the mass content is ≤0.1%;

[0304] The primary mother liquor F accounting for 90% of the total mass of the primary mother liquor F is returned to the concentration and crystallization step for reuse.

[0305] S07, resin separation: the primary mother liquor F accounting for 10% of the total mass of the primary mother liquor F is subjected to resin separation to obtain a secondary mother liquor G, which is returned to the concentration and crystallization process for reuse; the resin separation also obtains an extract H;

[0306] The secondary mother liquor G, calculated by mass percentage, comprises 15% GLY, 1% IDA-Na, an aqueous solution of trace sodium sulfate, wherein trace refers to a mass content of ≤0.1%, and the remainder is water;

[0307] Extract H, by mass percentage, includes 12% GLY, 5% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; Extract H is used to produce electronic grade IDA.

[0308] S08, GLY refining: purify and refine the GLY industrial-grade filter cake to obtain food-grade glycine;

[0309] GLY industrial-grade filter cake is successively subjected to GLY refining, crystallization separation, drying and airing to obtain food-grade glycine;

[0310] S09, IDA refining: the extract H is subjected to a first IDA refining and a second IDA refining to obtain electronic grade iminodiacetic acid;

[0311] The first IDA refining comprises: adjusting the pH value of the extract H to 2.1 with sulfuric acid at room temperature and pressure, and then evaporating and concentrating, desalting, cooling and crystallizing, centrifuging and drying to obtain industrial-grade iminodiacetic acid; 50% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining is sent to an incinerator as waste liquid I for harmless incineration treatment; the waste liquid I, by mass percentage, comprises 5% IDA-Na, 10% Na2SO4, 10% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water; 50% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining is returned to the concentration and crystallization process of step S05; the IDA circulating crystallization mother liquor comprises 5% IDA-Na, 10% Na2SO4, 10% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water. Na2SO4, 10% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water; the second IDA refining includes heating and dissolving industrial-grade iminodiacetic acid with desalted water, and then undergoing high-efficiency decolorization, complexing agent removal of heavy metal impurities, fine filtration, cooling crystallization, centrifugal separation, vacuum drying, and screening to obtain electronic-grade iminodiacetic acid.

[0312] Example 7

[0313] The difference between this embodiment and embodiment 5 is that hydroxyacetonitrile is prepared according to embodiment 1, the concentration of hydroxyacetonitrile is 49%, the pH is 1.5, and the rest is the same as embodiment 5.

[0314] Example 8

[0315] The difference between this embodiment and embodiment 5 is that hydroxyacetonitrile is prepared according to embodiment 3, the concentration of hydroxyacetonitrile is 51%, the pH is 3, and the rest is the same as embodiment 5.

[0316] Test example

[0317] A method for producing glycine and iminodiacetic acid using high-concentration coalbed methane comprises the following steps:

[0318] Preparation of hydroxyacetonitrile:

[0319] S011, raw coalbed methane 365Nm 3 / h (94.2% methane content) After the PSA impurity removal device, the refined coalbed methane with a methane content of 97% was obtained 342Nm3 / h;

[0320] S012, refined coalbed methane with a methane content of 97% 342Nm 3 / h (245.5kg / h) is preheated to T5 temperature alone, and after being uniformly mixed with 240kg / h of ammonia gas and 2450kg / h of fresh air at T6 temperature premixed, enters the fixed bed HCN reactor, and performs methane ammoxidation reaction under the action of platinum mesh catalyst at pressure P3 high temperature T7 to obtain synthesis reaction gas A (total mass 2935.5kg / h), and then the synthesis gas A is sent to the acid washing tower (98% concentrated sulfuric acid 251kg / h) for residual ammonia absorption, gas condensation cooling and water removal, to obtain synthesis gas B (2362.5kg / h) with a mass content of hydrocyanic acid of M4;

[0321] Among them, T5 is 65°C, T6 is 65°C, P3 is 0.08Mpa, T7 is 1100°C, M4 is 10.28%; the molar ratio of the ternary mixed gas is: ammonia: methane: air = 1: 1.05: 6.0;

[0322] S013, 2362.5 kg / h of hydrocyanic acid synthesis gas with a content of 10.28% reacts with a formaldehyde solution with a content of 37% (744.7 kg / h) to obtain 1005 kg / h of hydroxyacetonitrile aqueous solution with a content of 50.0%;

[0323] The mass concentration of formaldehyde is 37.0%, and the total molar ratio of hydrocyanic acid to formaldehyde is 1:1.02;

[0324] Hydrocyanic acid synthesis gas and formaldehyde react continuously in a first-stage and a second-stage absorption reactor connected in series, and the hydroxyacetonitrile circulating liquid produced by the reaction is respectively introduced into the corresponding first-stage and second-stage circulating receiving tanks, and part of the qualified hydroxyacetonitrile generated liquid in the first-stage receiving tank is extracted (the first-stage extraction volume is 1002 kg / h, the hydroxyacetonitrile concentration is 50.2%, the formaldehyde content is 0.08%, and the pH is 5.5), and then adjusted with 98% sulfuric acid under stirring in the first-stage intermediate tank to obtain a hydroxyacetonitrile intermediate with a pH of 1.85 and a concentration of 50.0%, and then pumped to a finished product tank for storage; Another part of the generated liquid in the first-stage receiving tank continues to circulate as a circulating reaction liquid, and is continuously metered to supplement the second-stage low-concentration circulating reaction liquid (hydroxyacetonitrile content 6.2%, formaldehyde content 10.5%, pH 6.5); the reaction tail gas of the second-stage absorption reactor is washed with pure water in the third-stage water washing tower, and the total tail gas (wherein the HCN analysis content is 0.2%, the temperature is ~20° C., and the pressure is 0.06MPa) is sent out for tail gas incineration treatment; the washing liquid of the water washing tower (hydroxyacetonitrile content 1.2%, formaldehyde content 0.5%, pH 6.8) is used in the second-stage absorption reaction tower;

[0325] S01, amination reaction: 760 kg / h of hydroxyacetonitrile and 1336 kg / h of concentrated ammonia water were mixed and reacted to obtain about 2096 kg / h of amination reaction liquid A;

[0326] The concentration of concentrated ammonia water is 28%, and the molar ratio of hydroxyacetonitrile to concentrated ammonia water is 1:3.3; hydroxyacetonitrile and concentrated ammonia water are continuously reacted in an ammonia reactor, hydroxyacetonitrile and concentrated ammonia water are mixed and preheated to a temperature T1, and reacted at a temperature T2 and a pressure P1 for a reaction time of t1 to obtain an ammonia reaction liquid A;

[0327] T1 is 50℃, T2 is 85℃, P1 is 1.5Mpa, and t1 is 6min;

[0328] S02, alkaline deamination: the amination reaction liquid A is subjected to alkaline deamination reaction with liquid alkali to obtain alkaline hydrolysis liquid B and gaseous ammonia;

[0329] The amination reaction solution A includes 16.0% NH2CH2CN, 1.51% NH(CH2CN)2, 12.7% NH3, trace amounts of HOCH2CN and nitrile polymers, and the remainder is water;

[0330] The liquid alkali is a sodium hydroxide solution, and the concentration of sodium hydroxide is 32%;

[0331] According to the proportion of HOCH2CN feed and liquid alkali for alkaline hydrolysis reaction, the molar ratio of HOCH2CN to NaOH is 1:1.15;

[0332] The ammoniation reaction liquid A (2096 kg / h) is mixed with liquid alkali (958 kg / h) and continuously enters the alkaline deamination reactor at pressure P2 and temperature T3 for alkaline deamination reaction. The residual ammonia remaining in the reaction liquid is removed by a deamination tower to remove gaseous ammonia and entrained water (490 kg / h) to obtain alkaline hydrolysis liquid B (2564 kg / h), wherein P2 is -62 Kpa, T3 is 80°C, and the removed gaseous ammonia is added with water to recover 28% concentrated ammonia water, which is returned to step S01 for reuse;

[0333] S03, ion membrane separation: using an ion membrane to perform electrodialysis separation on the alkaline solution B to obtain an electrodialysis solution C;

[0334] Alkaline hydrolysis solution B includes 24.44% NH2CH2COONa, 2.4% IDA-2Na, 1.2% NaOH, 71.5% H2O, and trace amounts of other impurities, wherein trace amounts of other impurities include sodium hydroxyacetate and sodium salt of nitrile polymer, and trace amounts refer to a mass content of ≤0.1%;

[0335] ① After the alkaline hydrolysis solution B (6500 kg / batch) is measured, it is put into the salt chamber circulation tank, pumped into the salt chamber by the metering pump, and then flows back to the circulation tank for closed-loop circulation; the initial solution in the alkali chamber circulation tank is deionized water (4500 kg / batch), which enters the alkali chamber for closed-loop circulation under the action of the peristaltic pump to discharge the air in the system;

[0336] ② Start the power supply of the membrane system and start running. Supply the system with materials at the specified flow rate. Operating conditions: temperature 30-50℃, membrane current 400-600A / m 2 , membrane voltage 1.0~4.0V / pair;

[0337] ③ The system consists of a primary and secondary bipolar ion membrane. During operation, glycine solution and alkali solution are taken out for analysis every 30 minutes. When the pH value of the primary membrane circulation is 8.0-10, the secondary membrane circulation is started. Finally, the pH value is 5-7 as the dialysis end point, and glycine solution and alkali solution can be respectively extracted.

[0338] ④ 6500kg / batch of alkaline hydrolysis solution (main content of NH2CH2COONa ~24.44%, 2.4% IDA-2Na, 1.2% NaOH, 71.8% H2O, trace amounts of other impurities), after removing Na+ through membrane, 5300kg / batch of glycine-containing solution (electrodialysis solution C) (including 21.2% GLY, 2.1% IDA-Na, 76.6% H2O, 0.1% other water-soluble impurities) is obtained, and 5700kg / batch of alkali solution (including 14.6% NaOH content) is recovered.

[0339] ⑤ The above-mentioned experimental separation is carried out through an ion membrane, and the salt chamber generates an electrodialysis solution C of 5300 kg / batch, wherein the electrodialysis solution C includes 21.2% GLY, 2.1% IDA-Na, 76.6% H2O, and 0.1% other water-soluble impurities by mass, and other water-soluble impurities include sodium hydroxyacetate and sodium salt of nitrile polymer; NaOH and H2O generated in the alkali chamber are returned to S02 and reused as alkali solution;

[0340] S04, decolorization: electrodialysis solution C (~1000kg / batch) is diluted and adjusted with 98% concentrated sulfuric acid 10.5kg / h + 70kg / h pure water in a decolorization kettle at a temperature of 70-75℃, and ~2kg / batch activated carbon is added. Keep for 60min to remove colored impurities, and then filter through a precision filter element to obtain decolorized filtrate D (~1080kg / batch);

[0341] Electrodialysis solution C is subjected to pH adjustment at temperature T4, and the activated carbon removes colored impurities in the feed solution, and then the decolorized filtrate D is obtained after filtration through a membrane core;

[0342] T4 is 70℃, the pH is adjusted to 5.5 with 98% concentrated sulfuric acid, and the activated carbon accounts for 2‰ of the total mass of the feed liquid;

[0343] Colored impurities include nitrile char and / or peptide polymers;

[0344] The decolorized filtrate D includes 19.6% by mass of GLY, 2.0% by mass of IDA-Na, 1.4% by mass of Na2SO4 and trace amounts of water-soluble sodium salt impurities, and the balance is water. The trace amounts of water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The trace amounts refer to a mass content of ≤0.1%;

[0345] S05, concentration and crystallization: the decolorized filtrate D is concentrated and crystallized to obtain a concentrated filtrate E;

[0346] The decolorized filtrate D (~5400kg / batch) is mixed with the mixed mother liquor (~4100kg / batch, 12% GLY, 5.2% IDA-Na, 10% Na2SO4, the balance is water) produced by the subsequent process and then enters an evaporation concentration device. Excess water (~4750kg / batch) is removed by reduced pressure distillation at a temperature of 70-80°C, and after removing (~190kg / batch) Na2SO4, a concentrated filtrate E (~4560kg / batch) is obtained; the concentrated filtrate E, by mass percentage, includes 34% GLY, 7.0% IDA-Na, 6.5% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; concentrated crystallization also obtains a by-product sodium sulfate (content 99%, ~190kg / batch).

[0347] S06, GLY crystallization separation: Concentrate the filtrate E (~5000 kg / batch) in a GLY crystallization tank for crystallization at a temperature of 20±2°C, and then centrifuge to obtain GLY industrial-grade filter cake (~870 kg / batch) and primary mother liquor F (~4130 kg / batch);

[0348] The weight content of GLY in the GLY industrial grade filter cake is 98%;

[0349] The primary mother liquor F, calculated by mass percentage, includes 20.6% GLY, 8.5% IDA-Na, 7.8% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides. The trace amount means that the mass content is ≤0.1%;

[0350] The primary mother liquor F accounting for 80% of the total mass of the primary mother liquor F is returned to the concentration and crystallization step for reuse.

[0351] S07, resin separation: the primary mother liquor F (~200kg / h) accounting for 20% of the total mass of the primary mother liquor F is mixed with pure water (~350kg / h) at room temperature, pressurized to ~0.4MPa by a pump and enters the resin separation device for continuous separation to obtain a secondary mother liquor G (~356kg / h), which is returned to the concentration and crystallization process for reuse; resin separation also obtains an extract H (~194kg / h);

[0352] The secondary mother liquor G comprises, by mass percentage, an aqueous solution of 11% GLY, 0.5% IDA-Na, 1.9% sodium sulfate, and the balance is water;

[0353] Extract H, by mass percentage, includes 8.5% IDA-Na, 4.5% Na2SO4, 0.3% GLY, trace water-soluble sodium salt impurities, and the balance is water. The trace water-soluble sodium salt impurities include hydroxyacetic acid and water-soluble sodium salts containing nitrile groups and polypeptides; Extract H is used to produce electronic grade IDA.

[0354] S08, GLY refining: purify and refine the GLY industrial-grade filter cake to obtain food-grade glycine;

[0355] GLY industrial-grade filter cake is successively subjected to GLY refining, crystallization separation, drying and airing to obtain food-grade glycine;

[0356] S09, IDA refining: the extract H is subjected to a first IDA refining and a second IDA refining to obtain electronic grade iminodiacetic acid;

[0357] The first IDA purification includes: adjusting the extract H (100 kg / batch) to pH = 2 ± 0.05 with 98% sulfuric acid (~5.5 kg / batch) in a stirred enamel kettle at room temperature and pressure, and then evaporating and concentrating the extract H (100 kg / batch) by negative pressure evaporation (temperature 85-100°C, pressure -0.08 MPa) to distill off water (~70 kg / batch) to obtain a concentrated solution (~35.5 kg / batch, content 18.5% IDA, 34% Na2SO4) is centrifuged while hot to obtain a by-product of 95% sodium sulfate (~11kg / batch), and 24.5kg / batch of desalted filtrate is mixed with 1kg / batch of centrifugal washing water, and then cooled and crystallized at 20~25℃, centrifuged, washed with 1kg / batch of pure water, and the filter cake is dried at a constant temperature of 105℃ to obtain industrial-grade iminodiacetic acid (6.1kg / batch) and crystallization mother liquor (20.2kg / batch); 40% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining is sent to an incinerator as waste liquid I for harmless incineration treatment; waste liquid I (8.1kg / batch), by mass percentage, includes 2.5% IDA, 8% Na2SO4, 5.2% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water; 60% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining is returned to the concentrated crystallization process of step S05; 2.5% of the IDA circulating crystallization mother liquor, IDA, 8% Na2SO4, 5.2% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water; the second IDA refining includes heating and dissolving industrial-grade iminodiacetic acid and desalted water, and then undergoing high-efficiency decolorization, complexing agent removal of heavy metal impurities, fine filtration, cooling crystallization, centrifugal separation, vacuum drying, and screening to obtain electronic-grade iminodiacetic acid.

[0358] The above is a detailed introduction to the method for producing glycine and iminodiacetic acid using high-concentration coalbed methane provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for producing glycine and iminodiacetic acid using high-concentration coalbed methane, characterized in that: The steps include: Amination reaction: Hydroxyacetonitrile and concentrated ammonia water are mixed and reacted to obtain an amination reaction solution A; Alkaline deamination: the amination reaction liquid A undergoes alkaline deamination reaction with liquid alkali to obtain alkaline hydrolysis liquid B and gaseous ammonia; Ion membrane separation: using an ion membrane to perform electrodialysis separation on the alkaline solution B to obtain an electrodialysis solution C; Decolorization: The electrodialysis solution C is subjected to decolorization to remove colored impurities and filtration to obtain a decolorized filtrate D; Concentration and crystallization: Decolorization filtrate D is concentrated and crystallized to obtain concentrated filtrate E; GLY crystallization separation: The concentrated filtrate E is subjected to GLY crystallization separation to obtain GLY industrial grade filter cake and primary mother liquor F; Resin separation: The primary mother liquor F, which accounts for 10% to 30% of the total mass of the primary mother liquor F, is subjected to resin separation to obtain a secondary mother liquor G, which is returned to the concentration and crystallization process for reuse; the resin separation also obtains an extract H; GLY refining: purify and refine GLY industrial-grade filter cake to obtain food-grade glycine; IDA refining: The extract H is subjected to the first IDA refining and the second IDA refining to obtain electronic grade iminodiacetic acid.

2. The method for producing glycine and iminodiacetic acid using high-concentration coalbed methane according to claim 1, characterized in that: The mass concentration of hydroxyacetonitrile is 49% to 51%, and the pH of hydroxyacetonitrile is 1.5 to 3; and / or The concentration of concentrated ammonia water is 20% to 35%; and / or The molar ratio of hydroxyacetonitrile to concentrated aqueous ammonia is 1:2.1 to 1:4.5; and / or The weight content of GLY in the GLY industrial grade filter cake is 98%.

3. The method for producing glycine and iminodiacetic acid using high-concentration coalbed methane according to claim 1, characterized in that: The hydroxyacetonitrile and concentrated ammonia solution are mixed and preheated to a temperature T1, and reacted at a temperature T2 and a pressure P1 for a reaction time of t1 to obtain an amination reaction solution A; and / or The ammoniation reaction liquid A is mixed with liquid alkali and continuously enters the alkaline deamination reactor at pressure P2 and temperature T3 to carry out alkaline deamination reaction, and the residual ammonia remaining in the reaction liquid is removed by a deamination tower to obtain alkaline hydrolysis liquid B; and / or The alkaline hydrolyzate B is separated by an ion membrane, and the salt chamber generates an electrodialysis solution C, and the alkaline chamber generates NaOH and H2O; and / or Electrodialysis solution C is subjected to pH adjustment at temperature T4, and activated carbon is used to remove colored impurities in the feed solution, and then filtered through a membrane core to obtain a decolorized filtrate D; and / or The decolorized filtrate D enters an evaporation concentration device to evaporate excess water and remove 40% to 90% by mass of Na2SO4 to obtain a concentrated filtrate E, which is concentrated and crystallized to obtain a by-product of sodium sulfate; and / or GLY industrial-grade filter cake is subjected to GLY refining, crystallization separation, drying and airing in sequence to obtain food-grade glycine; and / or The first IDA refining comprises: adjusting the pH value of the extract H to 1.9-2.1 with sulfuric acid at room temperature and pressure, and then evaporating and concentrating, desalting, cooling and crystallizing, centrifuging and drying to obtain industrial-grade iminodiacetic acid, and sending 30%-50% by weight of the IDA circulating crystallization mother liquor produced by the first IDA refining as waste liquid I to an incinerator for harmless incineration treatment; and / or The second IDA refining includes heating and dissolving industrial-grade iminodiacetic acid with desalted water, and then undergoing high-efficiency decolorization, removing heavy metal impurities with a complexing agent, fine filtration, cooling crystallization, centrifugal separation, vacuum drying, and screening to obtain electronic-grade iminodiacetic acid.

4. The method for producing glycine and iminodiacetic acid using high-concentration coalbed methane according to claim 3, characterized in that: T1 is 40°C to 60°C; and / or T2 is 55°C to 110°C; and / or P1 is 0.5Mpa to 2.5Mpa; and / or t1 is 3 min to 10 min; and / or P2 is -95Kpa~-30Kpa; and / or T3 is 50°C to 110°C; and / or T4 is 50°C to 90°C; and / or Adjust the pH value to 4-7 with concentrated sulfuric acid; and / or The activated carbon accounts for 1‰ to 3‰ of the total mass of the feed liquid; and / or Colored impurities include nitrile char and / or polypeptide polymers; and / or The removal rate of Na2SO4 is 40% to 90%.

5. The method for producing glycine and iminodiacetic acid using high-concentration coalbed methane according to claim 3, characterized in that: The removed gaseous ammonia is added with water to recover 20% to 35% concentrated ammonia water, which is returned to the step of amination reaction for reuse; and / or The NaOH and H2O generated in the alkali chamber are returned to the alkaline deamination step and reused as alkali solution; and / or The primary mother liquor F accounting for 70% to 90% of the total mass of the primary mother liquor F is returned to the concentration and crystallization step for reuse; and / or 50% to 70% by weight of the IDA circulating crystallization mother liquor produced in the first IDA purification is returned to the concentration and crystallization step.

6. The method for producing glycine and iminodiacetic acid by utilizing high-concentration coalbed methane according to claim 3, characterized in that: The amination reaction solution A comprises, by mass percentage, 15% to 22% NH2CH2CN, 1.0% to 2.5% NH ( CH2CN)2, 3% to 8% NH3, trace amounts of HOCH2CN and nitrile polymers, and the balance is water; and / or Alkaline hydrolysis solution B, by mass percentage, includes 15% to 30% NH2CH2COONa, 1% to 4% IDA-2Na, 1% to 3% NaOH, trace amounts of other impurities, and the balance is water, and trace amounts of other impurities include sodium hydroxyacetate and sodium salt of nitrile polymer; and / or Electrodialysis solution C, by mass percentage, comprises 12% to 25% GLY, 1% to 3% IDA-Na, trace water-soluble sodium salt impurities, and the balance is water, wherein the trace water-soluble sodium salt impurities include sodium hydroxyacetate and sodium salt of nitrile polymer; and / or The decolorized filtrate D comprises, by mass percentage, 15% to 20% GLY, 2% to 4% IDA-Na, 1% to 5% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water, wherein the trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; and / or The concentrated filtrate E comprises, by mass percentage, 25% to 35% GLY, 2% to 8% IDA-Na, 5% to 8% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water, wherein the trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; and / or The primary mother liquor F comprises, by mass percentage, 18% to 25% GLY, 4% to 10% IDA-Na, 6% to 10% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water, wherein the trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; and / or The secondary mother liquor G comprises, by mass percentage, 6% to 15% GLY, 0.1% to 1% IDA-Na, a trace amount of sodium sulfate, and the balance is water; and / or Extract H, by mass percentage, comprises 6% to 12% GLY, 1% to 5% Na2SO4, trace water-soluble sodium salt impurities, and the balance is water, the trace water-soluble sodium salt impurities include glycolic acid and water-soluble sodium salts containing nitrile groups and polypeptides; and / or Waste liquid I, by mass percentage, comprises 0.5% to 5% IDA-Na, 3% to 10% Na2SO4, 5% to 10% glycolic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the remainder is water; and / or The IDA circulating crystallization mother liquor comprises 0.5% to 5% IDA-Na, 3% to 10% Na2SO4, 5% to 10% hydroxyacetic acid and water-soluble sodium salt impurities containing nitrile groups and polypeptides, and the rest is water.

7. The method for producing glycine and iminodiacetic acid using high-concentration coalbed methane according to claim 1, characterized in that: The acquisition of hydroxyacetonitrile comprises the following steps: High-concentration coalbed methane is removed through the PSA impurity removal device to obtain methane; Methane reacts with ammonia and air to produce hydrocyanic acid; Hydrocyanic acid reacts with formaldehyde to obtain hydroxyacetonitrile.

8. The method for producing glycine and iminodiacetic acid using high-concentration coalbed methane according to claim 7, characterized in that: High-concentration coalbed methane, including, by mass percentage, 90% to 97% methane, 3% to 8% N2+O2, and the remainder being ethane, propane, butane, H2S and CO2; and / or The mass concentration of formaldehyde is 36.5% to 37%; and / or The molar ratio of hydrocyanic acid to formaldehyde is 1:1.01-1.2; and / or The mass concentration of hydroxyacetonitrile is 49% to 51%.

9. The method for producing glycine and iminodiacetic acid using high-concentration coalbed methane according to claim 7, characterized in that: The high-concentration coal-bed methane is incinerated in the tail boiler by the desorption gas obtained by the PSA impurity removal device. The desorption gas includes 88% to 96% methane, 4% to 12% N2+O2 by mass percentage, and the remainder is ethane, propane, butane, H2S and CO2; and / or Methane is preheated to a temperature of T5, mixed evenly with pre-mixed ammonia and air at a temperature of T6, and then enters a fixed bed reactor to undergo methane ammoxidation reaction at a high temperature of T7 with pressure P3 under the action of a platinum mesh catalyst to obtain a synthetic reaction gas A, and then the synthetic gas A is sent to a pickling tower for residual ammonia absorption and gas cooling to obtain a synthetic gas B with a mass content of hydrocyanic acid of M4.

10. The method for producing glycine and iminodiacetic acid by utilizing high-concentration coalbed methane according to claim 7, characterized in that: T5 is 50°C to 80°C; and / or T6 is 50°C to 80°C; and / or P3 is 0.07MPa to 0.15MPa; and / or T7 is 1000°C to 1200°C; and / or M4 is 8% to 12%; and / or The molar ratio of methane, ammonia and air is 1:1.05~1.2:5.5~7.0.

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