JPWO2010071016A1 - Method for producing acetic acid and ammonia - Google Patents

Abstract

Provided is a method for efficiently producing carboxylic acid and ammonia while reducing the generation amount of carbon dioxide. The above production method includes a carboxylic acid production step for producing carboxylic acid from carbon monoxide and alcohol, and an ammonia production step for producing ammonia from hydrogen and nitrogen, and a method for producing carboxylic acid and ammonia, A carbon monoxide / hydrogen separation step for separating carbon monoxide and hydrogen from synthesis gas (A) and a shift reaction step for producing hydrogen by shift reaction of synthesis gas (B), Carbon monoxide separated from the synthesis gas (A) is used, and hydrogen separated from the synthesis gas (A) in the ammonia production step and hydrogen obtained by the shift reaction step are used.

Description

  The present invention relates to a method for producing (co-production) carboxylic acid (such as acetic acid) and ammonia.

  Ammonia is obtained by the reaction of hydrogen and nitrogen, and synthesis gas is usually used as the hydrogen source for this reaction. The synthesis gas contains carbon monoxide in addition to hydrogen, and the carbon monoxide and water are subjected to a so-called water gas shift reaction and used for ammonia production. Such a shift reaction can use a large amount of hydrogen in the production of ammonia, but a large amount of carbon dioxide is by-produced by the shift reaction.

  On the other hand, acetic acid is generally obtained by a reaction of carbon monoxide and methanol, and synthesis gas is usually used as a carbon monoxide source for this reaction. Hydrogen that is unnecessary in this reaction is used in the synthesis of methanol, dimethyl ether, and the like. However, carbon monoxide is also required in these syntheses, and a process for more effectively using the synthesis gas is required.

  Attempts to improve the utilization efficiency of synthesis gas have also been reported. WO 01/32594 (Patent Document 1) discloses a method for producing a reaction product such as acetic acid from carbon monoxide and methanol, which includes hydrogen, carbon monoxide and carbon dioxide from hydrocarbons such as natural gas. A method is disclosed that includes a step of generating a gas and a step of converting hydrogen and carbon monoxide in the synthesis gas into methanol. In this document, a part or all of the synthesis gas is separated and separated into carbon dioxide rich, carbon monoxide rich and hydrogen rich gas streams, respectively. It is described that it can be fed and that a hydrogen-rich gas stream can be used for the synthesis of ammonia. That is, although this method proposes co-production of acetic acid and ammonia, methanol and acetic acid as raw materials for acetic acid are produced from the same synthesis gas. Therefore, this method does not focus on carbon dioxide produced as a by-product in the shift reaction in ammonia production, but can use only a small amount of carbon dioxide contained in the synthesis gas for synthesis of the synthesis gas. There is an upper limit to the amount of return to the synthesis gas. In addition, this method uses natural gas as a raw material for methanol synthesis, and requires a synthesis gas having a high hydrogen content. Therefore, a large-scale separation device or an additional separation device is required for separating a large amount of hydrogen in a later process. Furthermore, this method cannot effectively utilize oxygen separated from air used as a nitrogen source for ammonia synthesis.

WO 01/32594 (Claims and Figures)

  Accordingly, an object of the present invention is to provide a method for efficiently producing a carboxylic acid (such as acetic acid) and ammonia.

  Another object of the present invention is to provide a method for producing carboxylic acid and ammonia while reducing the amount of carbon dioxide generated.

  Still another object of the present invention is to provide a method for producing carboxylic acid and ammonia while reducing the amount of carbonaceous material (for example, coal) used as a raw material for synthesis gas.

  Another object of the present invention is to provide a method for producing carboxylic acid and ammonia while effectively utilizing oxygen by-produced for the production of ammonia.

  Still another object of the present invention is to provide a method for producing carboxylic acid and ammonia while controlling the production amount (production ratio).

  As a result of intensive studies to achieve the above-mentioned problems, the present inventor (1) separated carbon monoxide from synthesis gas (synthetic gas derived from petroleum, coal, natural gas, etc., in particular, synthetic gas derived from coal). In the method of using the hydrogen separated from the synthesis gas used for the production of carboxylic acid (such as acetic acid) for the production of ammonia, the synthesis gas is added to the synthesis of ammonia in addition to the hydrogen separated from the synthesis gas. Or a method using hydrogen obtained by a shift reaction of the same synthesis gas (especially the same synthesis gas), or (2) monoxide from synthesis gas in which the molar ratio of carbon monoxide to hydrogen is relatively close to 1. Carboxylic acid and ammonia can be efficiently produced by separating carbon and using it in the production of carboxylic acids (such as acetic acid) and using hydrogen separated from the synthesis gas in the production of ammonia. (In particular, in the method (1), these can be efficiently produced while controlling the production ratio of carboxylic acid and ammonia), and furthermore, the same amount of carboxylic acid and ammonia are each independently a carbonaceous material (for example, The present invention has been completed by discovering that the amount of carbon dioxide generated and the amount of carbonaceous material (such as coal) used as a raw material for synthesis gas can be reduced as compared with the case of producing from synthesis gas derived from coal.

  That is, the production method (first method) of the present invention includes a carboxylic acid production process for producing carboxylic acid from carbon monoxide and alcohol, and ammonia production for producing ammonia from hydrogen and nitrogen. A process for producing carboxylic acid and ammonia, comprising: a carbon monoxide / hydrogen separation step for separating carbon monoxide and hydrogen from synthesis gas (A); and synthesis gas (B). A shift reaction step for producing hydrogen by shift reaction of carbon monoxide separated from the synthesis gas (A) in the carboxylic acid production step (or separated from the synthesis gas (A)) Carbon monoxide is supplied to the carboxylic acid production process, specifically, the carboxylic acid is produced using the carbon monoxide separated from the synthesis gas (A)), and before the ammonia production process. Using the hydrogen separated from the synthesis gas (A) and the hydrogen obtained by the shift reaction step (or the hydrogen separated from the synthesis gas (A) and the hydrogen obtained by the shift reaction step in the ammonia production step Specifically, ammonia is produced using hydrogen separated from the synthesis gas (A) and hydrogen obtained by the shift reaction step). In this method, the synthesis gas (A) is not particularly limited, and for example, synthesis gas derived from petroleum, coal, natural gas or the like can be used.

  Further, another production method (second method) of the present invention includes a carboxylic acid production process for producing carboxylic acid from carbon monoxide and alcohol, and production of ammonia from hydrogen and nitrogen (for). A method for producing a carboxylic acid and ammonia, comprising an ammonia production step, wherein the ratio of carbon monoxide to hydrogen is the former / the latter (molar ratio) = 1 / 0.4 to 1 / 1.5. A carbon monoxide / hydrogen separation step for separating carbon monoxide and hydrogen from the synthesis gas (A), and using the carbon monoxide separated from the synthesis gas (A) in the carboxylic acid production step. (Or carbon monoxide separated from the synthesis gas (A) is supplied to the carboxylic acid production process, specifically, the carbon monoxide separated from the synthesis gas (A) is used to produce the carboxylic acid), and Before in the ammonia production process The hydrogen separated from the synthesis gas (A) is used (or the hydrogen separated from the synthesis gas (A) is supplied to the ammonia production process. More specifically, the hydrogen separated from the synthesis gas (A) is used to produce ammonia. Manufacturing method).

  Such a method (first or second method) further includes a synthesis gas production step for producing a synthesis gas by gasifying a carbonaceous material (or a hydrocarbon source, for example, coal), The synthesis gas produced in this synthesis gas production process may be used as synthesis gas (A). The method further includes an oxygen / nitrogen separation step for separating nitrogen and oxygen from air, and the oxygen separated in the oxygen / nitrogen separation step is used as a gas of a carbonaceous material (for example, coal). Nitrogen separated in the oxygen / nitrogen separation step may be used in the ammonia production step. By incorporating such an oxygen / nitrogen separation step into a series of the production steps, oxygen separated from air as a nitrogen source required in the ammonia production step can be effectively used, which is advantageous in terms of energy efficiency.

  In the second method, as in the first method, hydrogen separated from the synthesis gas (A) in the ammonia production step and synthesis gas (B) (synthesis gas (B) different from synthesis gas (A)). ) And hydrogen obtained by the shift reaction may be used. That is, the second method further includes a shift reaction step for producing hydrogen by shift reaction of the synthesis gas (B), and hydrogen separated from the synthesis gas (A) in the ammonia production step. And hydrogen obtained by the shift reaction step may be used. In the first and second methods, “hydrogen obtained by the shift reaction (step)” means a mixture of hydrogen contained in the synthesis gas (B) and hydrogen newly produced by the shift reaction. Means gas. By using such a shift reaction, it is possible to co-produce carboxylic acid while adjusting the amount of ammonia produced, thus reducing the amount of carbon dioxide generated (emissions) (and reducing the amount of coal used). However, carboxylic acid and ammonia can be produced at a desired ratio.

  In particular, in the first and second methods, the synthesis gas (A) and the synthesis gas (B) may be a synthesis gas produced in the same synthesis gas production process. That is, the synthesis gas produced in the synthesis gas production process is divided into a synthesis gas (A) and a synthesis gas (B) (divided) and used for a carbon monoxide / hydrogen separation process and a shift reaction process, respectively. Also good. When the same synthesis gas production process is used, the production amount of carboxylic acid and ammonia can be adjusted while simplifying the process.

  In the method of the present invention (first and second methods), since a syngas shift reaction is used or a specific syngas having a small proportion of hydrogen (especially, a syngas derived from coal) is used, a carboxylic acid ( Acetic acid and the like) and ammonia can be produced efficiently. In particular, in the methods of the present invention (first and second methods), compared to the case where the same amount of carboxylic acid and ammonia are each independently produced from synthesis gas, the amount of carbon dioxide generated and the raw material for synthesis gas are obtained. Carboxylic acid and ammonia can be produced while reducing the amount of carbonaceous material (for example, coal) used. In addition, carboxylic acid and ammonia can be produced while effectively using oxygen produced as a by-product for producing ammonia. Therefore, the method of the present invention is a very advantageous process in terms of environment, industry, and cost. Furthermore, in the method of the present invention (first and second methods), the production can be performed while controlling the production amount (production ratio) of carboxylic acid and ammonia by utilizing a shift reaction. By using such a shift reaction, the production amount of carboxylic acid and ammonia can be controlled even if the carbon monoxide / hydrogen ratio in the carbonaceous material changes.

FIG. 1 is a flowchart for explaining an example of the production method (or production apparatus) of the present invention. FIG. 2 is a flowchart for explaining another example of the production method (or production apparatus) of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings as necessary. FIG. 1 is a flowchart for explaining an example of the production method (and production apparatus) of the present invention. FIG. 2 is a flowchart for explaining another example of the production method (and production apparatus) of the present invention. In the example of FIG. 1, a method (apparatus) for producing carboxylic acid by reacting carbon monoxide separated from coal-derived synthesis gas with alcohol or a derivative thereof, and ammonia using hydrogen separated from the synthesis gas. The method (apparatus) which manufactures is shown.

  This production method (apparatus) produces an oxygen / nitrogen separation unit 1 for separating nitrogen and oxygen from air, and produces coal by gasifying coal using the oxygen separated in this unit 1 to produce synthesis gas (A). And a carbon monoxide / hydrogen separation unit 3 for separating carbon monoxide and hydrogen from the synthesis gas (A) produced by the unit 2 and the unit 3 for separation. A carboxylic acid production unit 4 for producing carboxylic acid from carbon monoxide and alcohol; and an ammonia production unit 5 for producing ammonia from hydrogen separated from the unit 3 and nitrogen separated from the separation unit 1. I have.

  And this manufacturing method (apparatus) is oxygen supply for supplying various lines for supplying each component to these units, that is, oxygen separated by the oxygen / nitrogen separation unit 1 to the synthesis gas manufacturing unit 2. Line 1A, nitrogen supply line 1B for supplying nitrogen separated by oxygen / nitrogen separation unit 1 to ammonia production unit 5, and synthesis gas produced by synthesis gas production unit 2 as synthesis gas (A) A synthesis gas supply line 2A for supplying the carbon monoxide / hydrogen separation unit 3; a carbon monoxide supply line 3A for supplying the carbon monoxide separated from the separation unit 3 to the carboxylic acid production unit 4; A hydrogen supply line 3B for supplying hydrogen separated from the separation unit 3 to the ammonia production unit 5; .

  First, in the synthesis gas production unit 2, coal is gasified to produce synthesis gas (A). In this example, coal is gasified by partial oxidation using oxygen separated by the oxygen / nitrogen separation unit 1. Coal gasification is usually performed at high temperature and high pressure. Examples of the separation method in the oxygen / nitrogen separation unit 1 include a conventional method, for example, a method of separating compressed air and compressed nitrogen from air. Specifically, the unit 1 may include an air compressor, an oxygen compressor, a nitrogen compressor, and the like.

  Coal may be gasified using water (steam) in addition to oxygen. For example, a slurry of coal and water may be partially oxidized with oxygen. This method is preferable because oxygen, which is a by-product of air used for the production of ammonia, can be used. In a synthesis gas production process using natural gas or the like, such oxygen is usually not used and oxygen cannot be effectively used.

  The synthesis gas production unit 2 may be provided with a reactor for coal gasification, and may be provided with a heat recovery device (cooling device) for heat recovery (cooling) of the generated synthesis gas. . Further, the heat recovered may be supplied to other processes or units as necessary, and used for other processes or reactions.

The synthesis gas produced by the synthesis gas production unit 1 is a coal-derived gas, and a synthesis in which the ratio of hydrogen (H ₂ ) to carbon monoxide (CO) is relatively small compared to a synthesis gas derived from natural gas. Gas. For example, in the synthesis gas (synthesis gas (A)), the ratio of carbon monoxide to hydrogen is the former / the latter (molar ratio) = 1 / 0.4 to 1 / 1.5, preferably 1 / 0.5. Is about 1 / 1.2, more preferably about 1 / 0.6 to 1/1 (for example, 1 / 0.65 to 1 / 0.9). In the present invention, by using such a synthesis gas, the hydrogen to be separated in the carbon monoxide / hydrogen separation unit (or the carbon monoxide / hydrogen separation step) can be reduced. The amount of carbon dioxide generated can be reduced.

  In addition to carbon monoxide and hydrogen, the synthesis gas usually contains other components [water, carbon dioxide, hydrocarbons (such as methane), hydrogen sulfide, etc.]. Such other components are less than carbon monoxide and hydrogen, but are preferably not fundamentally present because they may adversely affect (for example, become catalyst poisons) in later steps. However, since there may be a limit in producing synthesis gas without by-producting such other components, it may be appropriately separated in a separation step or the like. In particular, the ratio of carbon dioxide contained in the synthesis gas (A) is, for example, in the range of 0 to 0.6 mol with respect to 1 mol of carbon monoxide contained in the synthesis gas (A). 01 to 0.5 mol (for example, 0.1 to 0.5 mol, preferably 0.25 to 0.45 mol), more preferably 0.3 to 0.4 mol (for example, 0.33 to 0.3 mol). 38 mol).

  The synthesis gas produced by the synthesis gas production unit 2 is supplied to the separation unit 3 through the synthesis gas supply line 2A as synthesis gas (A). In the separation unit 3, carbon monoxide and hydrogen are separated. Examples of the separation method in the unit 3 include a conventional method such as a membrane separation method, a cryogenic separation method, and a PSA (pressure swing adsorption) method. For relatively large-scale separation, a cryogenic separation method can be suitably used. The order of separation of these components from the synthesis gas (A) is not particularly limited, and after separating hydrogen from the synthesis gas, carbon monoxide may be separated or vice versa.

  In addition to the carbon monoxide, the synthesis gas (or the gas after hydrogen separation) contains other gases as described above. In particular, acid gases (carbon dioxide, hydrogen sulfide, etc.) are more strictly removed from the separated carbon monoxide and / or hydrogen because they can have adverse effects in subsequent processes, particularly in the ammonia production process. Is preferred. Therefore, these components may be separated and removed in the separation unit 3 (carbon monoxide / hydrogen separation step) or the removal unit connected in front of the separation unit. Usually, before separating carbon monoxide and hydrogen, acidic gas or the like is often separated. In the illustrated example, carbon dioxide, which is a typical gas, is separated and removed in the separation unit 3 (a unit including an acid gas removal unit) (usually, carbon dioxide is separated prior to separation of carbon monoxide and hydrogen). Removed). In the illustrated example, a gas such as hydrogen sulfide is not shown.

  Carbon monoxide and hydrogen separated by the separation unit 3 are supplied to the carboxylic acid production unit 4 and the ammonia production unit 5 through lines 3A and 3B, respectively. In ammonia production, carbon monoxide and carbon dioxide are components that extremely inhibit the reaction, and therefore must be strictly removed. Therefore, if necessary, the hydrogen (gas) separated in the separation unit 3 (or separation step) is further separated by a conventional method such as a methanator treatment (a treatment for converting carbon monoxide to methane) ( Alternatively, it may be supplied to the ammonia production unit 5 (not shown).

  In the carboxylic acid production unit 4 and the ammonia production unit 5, carboxylic acid and ammonia are produced. In such a manufacturing apparatus or manufacturing method, acetic acid and ammonia can be produced together while reducing the amount of carbon dioxide generated. As a specific model case, a case where acetic acid is produced at a rate of 500,000 tons / year is assumed.

In the case of producing acetic acid at a rate of 500,000 tons / year, coal as a raw material is required at a rate of 35 tons / h as an example, and is included in the synthesis gas (A) obtained by gasifying such coal. The rate of CO is 28000 Nm ³ / h, the rate of H ₂ is 23000 Nm ³ / h, and the rate of CO ₂ is 12000 Nm ³ / h (ie, CO / H ₂ / CO ₂ (molar ratio) = 1 / 0.85). /0.49). In addition, the gasification of coal was calculated on the assumption that the coal slurry method is used. Assuming that ammonia is produced by separating 100% of hydrogen from this synthesis gas (A), ammonia is produced at a rate of 95,000 tons / year, and carbon dioxide is 12000 Nm ³ / h as described above. Occurs at a rate of.

On the other hand, if acetic acid and ammonia are separately produced from coal by the coal slurry method at such a rate, first, in order to produce acetic acid at a rate of 500,000 tons / year, as described above, CO ₂ Is produced at a rate of 12000 Nm ³ / h. In addition, in order to produce ammonia at a rate of 95,000 tons / year, coal is required at a rate of 15.0 tons / h when all the carbon monoxide is converted to hydrogen by a shift reaction (as synthesis gas). CO is 13000Nm ³ / h, _{H 2} is 11000Nm ³ / h, CO ₂ is produced at a rate of 5600Nm ³ / h), and the carbon dioxide contained in the carbon dioxide (synthesis gas at a rate of 18600Nm ³ / h 5600Nm ³ / h, and 13000 Nm ³ / h of carbon dioxide generated by the shift reaction is generated.

That is, in the case of producing at a rate of 500,000 tons / year of acetic acid and 95,000 tons / year of ammonia, the amount of coal used can be reduced at a rate of 15 tons / h, and the amount of carbon dioxide generated is 6600 Nm ³ / h. Can be reduced at a rate of.

  In the example shown in FIG. 2, an apparatus (or method) for producing carboxylic acid by reacting carbon monoxide and alcohol separated from synthesis gas, and hydrogen and synthesis gas separated from the synthesis gas were obtained by shift reaction. 1 shows an apparatus (or method) for producing ammonia using hydrogen.

The production method (apparatus) of this figure includes a synthesis gas supply line 2B for supplying the synthesis gas produced in the synthesis gas production unit 2 to the shift reaction unit as a synthesis gas (B) separately from the synthesis gas (A), 2B further includes a shift reaction unit 10 that shifts the synthesis gas (B) supplied through 2B to produce hydrogen, and a hydrogen supply line 10A that supplies the hydrogen obtained by the shift reaction unit 10 to the ammonia production unit 5. The apparatus (or method) is the same as that shown in FIG. In the example shown in FIG. 2, synthesis gas is produced using coal in the synthesis gas production unit 2. However, in the example shown in FIG. 2, since a shift reaction can be used, the synthesis gas derived from coal is not necessarily used. It is not necessary to use a synthesis gas having a relatively small ratio of hydrogen (H ₂ ) to carbon monoxide (CO).

  That is, in this example, the synthesis gas (A) and the synthesis gas (B) produced in the same synthesis gas production unit 2 (or production process) are divided and the synthesis gas (B) is subjected to a shift reaction. The amount of hydrogen supplied to the ammonia production unit (production process) is controlled. Specifically, the ammonia production unit 5 is supplied with hydrogen separated from the synthesis gas (A) and hydrogen separated from the shift reaction unit 10 through a shift reaction. By using such a shift reaction, the amount of carbon dioxide produced can be reduced while controlling the ratio between the amount of carboxylic acid produced and the amount of ammonia produced. The shift reaction is represented by the following formula.

CO + H ₂ O → CO ₂ + H ₂
The shift reaction unit 10 only needs to include a synthesis gas shift reaction device (reactor). Usually, the shift reaction unit 10 performs a shift reaction, and hydrogen from the gas after the shift reaction (hydrogen and shift contained in the synthesis gas in advance). It has a separation device (process) for separating (hydrogen generated by the reaction) and supplying it to the supply line 10A. That is, since the gas after the shift reaction contains a large amount of other components as described above, particularly carbon dioxide by-produced by the shift reaction, an apparatus (process) for newly separating hydrogen is required. Become. As a method for separating hydrogen, the same separation method as described above, a rectisol process, a methanator method, and the like can be used.

In the manufacturing apparatus or manufacturing method of FIG. 2, it can manufacture, controlling the production amount of acetic acid and ammonia. In particular, in the example of FIG. 1, the amount of acetic acid and ammonia produced is limited by the ratio of carbon monoxide / oxygen in the coal-derived synthesis gas, and a large amount of ammonia cannot be produced. In the example of FIG. The production amount can be increased. In addition, the production amount can be adjusted in balance with the production amount of acetic acid, and the amount of carbon dioxide emission and the coal usage fee can be reduced. Furthermore, even if the supply and demand balance of the hydrocarbon source fluctuates, acetic acid and ammonia can be stably generated by controlling the ratio of CO / H ₂ .

  As a specific model case, it is assumed that acetic acid is produced at a rate of 500,000 tons / year and ammonia is produced at a rate of 500,000 tons / year. In this case, the raw material coal is required at a rate of 100 tons / h.

That is, out of 100 ton / h coal, when 35 ton / h coal is used for synthesis gas (A), CO is 28000 Nm ³ / h and H ₂ is 23000 Nm in the synthesis gas (A). ³ / h, CO ₂ is contained at a rate of 12000 Nm ³ / h (that is, CO / H ₂ / CO ₂ (molar ratio) = 1 / 0.85 / 0.49). In addition, the gasification of coal was calculated by performing the coal slurry method as described above.

On the other hand, among the 100 tons / h coal, the remaining 65 tons / h coal is used for the synthesis gas (B). The synthesis gas (B) contains CO at a rate of 54000 Nm ³ / h, H ₂ at 46000 Nm ³ / h, and CO _{2 at} a rate of 24000 Nm ³ / h.

Then, assuming that all the CO in the synthesis gas (B) is subjected to a shift reaction, hydrogen and carbon dioxide are generated in the same amount as CO, that is, at a rate of 54000 Nm ³ / h. When ammonia is produced using all of this hydrogen, ammonia can be obtained at a rate of 500,000 tons / year.

On the other hand, if such acetic acid and ammonia are individually produced from coal by the coal slurry method, first, in order to produce acetic acid at a rate of 500,000 tons / year, 35 tons of coal is used as described above. / ₂ is required, and CO ₂ is generated at a rate of 12000 Nm ³ / h. Further, in order to produce ammonia at a rate of 500,000 tons / year, when all the carbon monoxide is converted to hydrogen by a shift reaction, coal is at a rate of 80 tons / h (CO is 67000 Nm ³ / h as synthesis gas). , _{H 2} is 57000Nm ³ / h, CO ₂ is produced at a rate of 30000 nM ³ / h) required, the carbon dioxide contained in the carbon dioxide (synthesis gas 97000Nm ³ / h is 30000 nM ³ / h, the shift reaction The generated carbon dioxide is 67000 Nm ³ / h).

In summary, in the case of producing at a rate of 500,000 tons / year of acetic acid and 500,000 tons / year of ammonia, the amount of coal used can be reduced at a rate of 15 tons / h, and the amount of carbon dioxide generated can be reduced to 19000 Nm ³ / h. It can be reduced at a rate of h.

  In the method or apparatus of the present invention, the synthesis gas is usually a gas obtained by modifying a carbonaceous material. The carbonaceous material can be selected according to the method (1) or (2). In the method (1), the synthesis gas is not limited to coal, and may be any of petroleum, natural gas, and the like. In the method (1), the ratio of carbon monoxide to hydrogen is not necessarily limited to the above range because a shift reaction is used, and the former / the latter (molar ratio) = 1 / 0.2 to 1/4. Preferably, it may be about 1 / 0.4 to 1 / 3.5, more preferably about 1 / 0.6 to 1/3. In particular, also in the method (1), as in the example of FIG. 2, a synthesis gas (coal-derived synthesis gas) containing carbon monoxide and hydrogen in the specific range may be used. In the method (1), the ratio of carbon dioxide in the synthesis gas is in the same range as described above.

  In the method (2), the synthesis gas is not limited to coal as long as a synthesis gas having a small hydrogen ratio can be obtained. That is, as the synthesis gas, it is not always necessary to use a synthesis gas derived from coal, but usually coal can be suitably used as the carbonaceous material.

  In the methods (1) and (2), the coal may be any of anthracite, bituminous coal, subbituminous coal, lignite, and the like.

  The reforming method can be appropriately selected according to the type of carbonaceous material. For example, the gasification method for coal is not particularly limited. For example, the coal slurry gasification method includes a GE method, and the coal dry feed gasification method includes a Shell method, an SFGT method (Siemens Fuel Gasification Technology), and the like. is there. 1 and 2 use oxygen, it is not always necessary to adopt a gasification method using oxygen. However, in consideration of the scale of the gasifier and the commercialization of carbon monoxide in the subsequent process, it is common to use oxygen as the oxidant.

  The gasification temperature of coal may be, for example, about 1300 to 1500 ° C, preferably about 1350 to 1450 ° C. Further, the gasification pressure of coal can usually be selected from a range of 10 MPa or less, and is determined according to the purpose of use of the generated gas (synthesis gas). For example, the gasification pressure of coal may be about 4 to 10 MPa. Coal gasification may be performed in the absence of a catalyst or in the presence of a suitable catalyst depending on the gasification method. The gasification method using water and oxygen may be performed in the absence of a catalyst.

  In the carbon monoxide / hydrogen separation unit (or separation step) and the shift reaction unit (or shift reaction step), as described above, it is usually preferable to separate and remove other components, particularly acidic gas. The separation and removal of these components may be performed from the synthesis gas itself, may be further performed on carbon monoxide and / or hydrogen after separation from the synthesis gas, or a combination thereof. A conventional method can be used as the separation and removal method. For example, a conventional method such as a rectisol process can be used as the acid gas removal method. Note that hydrogen sulfide may be further separated from the separated acid gas as a sulfur source.

  The synthesis gas (B) used in the shift reaction unit (or the shift reaction process) uses the synthesis gas obtained through the same synthesis gas production process as the synthesis gas (A) in the example of the above figure. As long as the synthesis gas (B) is different from the synthesis gas (A), the synthesis gas obtained through different processes (for example, a gas derived from coal, a gas derived from components other than coal (petroleum, natural gas, etc.)) It may be. Further, the synthesis gas (A) and the synthesis gas (B) may be the same or different in the composition ratio of each component (carbon monoxide, hydrogen, carbon dioxide, etc.). In particular, when the synthesis gas (B) is a synthesis gas obtained in the same process as the synthesis gas (A) as in the example of the figure, it is advantageous because the process and apparatus can be simplified. In the illustrated example, the synthesis gas (A) and the synthesis gas (B) have the same composition.

  In the shift reaction unit (or shift reaction step), the shift reaction conditions are not particularly limited, and conventional conditions can be used. The shift reaction temperature may be, for example, 200 to 600 ° C., preferably 250 to 550 ° C., and more preferably about 300 to 500 ° C. The shift reaction may be performed in the presence of a shift reaction catalyst (for example, an iron / chromium catalyst).

  The mixed gas after the shift reaction may be heat recovered (or cooled) as necessary. If necessary, the heat recovered may be supplied to another process or unit and used for a heating reaction in another process.

  Each line may include a control unit (such as a flow rate control unit) for adjusting the supply amount of each component (such as synthesis gas, carbon monoxide, hydrogen, oxygen, and nitrogen).

In the carboxylic acid production process (or production unit), the alcohol is not particularly limited. For example, aliphatic alcohols [C _1-10 alkanols such as alkanol (eg, methanol, ethanol, propanol, isopropanol, butanol, pentanol, etc.) ), Cycloalkanols (eg, C _4-10 cycloalkanols such as cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, etc.)], phenols (eg, hydroxy C _6-10 arenes such as phenol), aromatic fats Group alcohols (for example, hydroxy C _1-4 alkyl C _6-10 arenes such as benzyl alcohol and phenethyl alcohol). Typically, aliphatic monools (eg, C _1-4 alkanols such as methanol), particularly methanol, may be mentioned.

  In the carboxylic acid production process, the reaction conditions of carbon monoxide and alcohol are not particularly limited, and conventional conditions and equipment can be used. Carboxylic acid may be usually performed in a liquid phase reaction system. For example, in the reaction system of the carboxylic acid production process, the pressure (or partial pressure) of carbon monoxide may be, for example, 200 to 3000 kPa (for example, 400 to 1500 kPa), preferably about 500 to 1000 kPa. The reaction temperature may be, for example, about 100 to 300 ° C., preferably about 150 to 250 ° C. (for example, 170 to 220 ° C.), and the reaction pressure may be about 1000 to 5000 kPa (for example, 1500 to 4000 kPa). There may be.

The reaction between carbon monoxide and alcohol may be performed in the presence of a catalyst. Examples of the catalyst include a conventional carbonylation catalyst such as a transition metal catalyst (rhodium catalyst, iridium catalyst, platinum catalyst, palladium catalyst, copper catalyst, nickel catalyst, etc.). The concentration of the catalyst may be, for example, about 5 to 10,000 ppm, preferably about 10 to 5000 ppm on a weight basis with respect to the liquid phase reaction system. Further, promoters or reaction accelerators [metal halides (for example, alkali metal halides such as lithium iodide, potassium iodide, sodium iodide, lithium bromide), hydrogen halides (for example, hydrogen iodide, hydrogen bromide, etc. ), Halogenated hydrocarbons (eg, halo C _1-4 alkanes such as methyl iodide and methyl bromide), etc.] may be used in combination. And the carboxylic acid (for example, acetic acid) produced | generated at the carboxylic acid manufacturing process can be refine | purified and collect | recovered by a conventional method.

  For the carboxylic acid production process (or production unit), conventional methods such as Japanese Patent No. 3244385 and Japanese Patent Application Laid-Open No. 2002-255890 may be referred to.

  In the ammonia production process (or production unit), the reaction conditions between hydrogen and nitrogen are not particularly limited, and conventional conditions and equipment can be used. For example, the reaction temperature may be, for example, about 300 to 700 ° C., preferably about 350 to 650 ° C. (for example, 400 to 600 ° C.), and the reaction pressure may depend on the low pressure method, the intermediate pressure method, the high pressure method, or the like. It can select suitably, For example, about 5-50 Mpa (for example, 10-30 Mpa) may be sufficient.

  The reaction between hydrogen and nitrogen may be performed in the presence of a catalyst. Examples of the catalyst include conventional catalysts, for example, transition metal catalysts such as iron-based catalysts (for example, triiron tetroxide) and ruthenium-based catalysts (Ru / C-based catalysts). Furthermore, a cocatalyst [for example, alkali metal or alkaline earth metal oxide (such as potassium oxide, magnesium oxide, calcium oxide), aluminum compound (such as alumina), silicon compound (such as silicon dioxide), etc.) may be used in combination. . And the ammonia produced | generated at the ammonia manufacturing process can be refine | purified and collect | recovered by a conventional method.

  In the production method and production apparatus of the present invention, carboxylic acid (such as acetic acid) and ammonia can be produced efficiently from synthesis gas (especially, synthesis gas using cheap coal as a raw material). In addition, the amount of carbon dioxide and carbonaceous material (especially coal) can be reduced, which is extremely advantageous in terms of environment, industry, and cost. Moreover, since the production amount of carbon monoxide and hydrogen can be controlled, carboxylic acid and ammonia can be produced with a desired production amount.

DESCRIPTION OF SYMBOLS 1 ... Oxygen / nitrogen separation unit 2 ... Syngas production unit 3 ... Carbon monoxide / hydrogen separation unit 4 ... Carboxylic acid production unit 5 ... Ammonia production unit 1A ... Oxygen supply line 1B ... Nitrogen supply line 2A, 2B ... Syngas supply Line 3A ... Carbon monoxide supply line 3B ... Hydrogen supply line 10 ... Shift reaction unit 10A ... Hydrogen supply line

Claims (5)

  A process for producing a carboxylic acid and ammonia, comprising a carboxylic acid production process for producing a carboxylic acid from carbon monoxide and an alcohol, and an ammonia production process for producing ammonia from hydrogen and nitrogen. A carbon monoxide / hydrogen separation step for separating carbon monoxide and hydrogen from the synthesis gas (A) and a shift reaction step for producing hydrogen by shift reaction of the synthesis gas (B). Carbon monoxide separated from the gas (A) is used in the carboxylic acid production step to produce carboxylic acid, and hydrogen separated from the synthesis gas (A) and hydrogen obtained by the shift reaction step are used. A production method for producing ammonia using the ammonia production process.   A process for producing carboxylic acid and ammonia, comprising a carboxylic acid production process for producing carboxylic acid from carbon monoxide and alcohol, and an ammonia production process for producing ammonia from hydrogen and nitrogen, comprising: Carbon monoxide / hydrogen for separating carbon monoxide and hydrogen from synthesis gas (A) in which the ratio of carbon oxide to hydrogen is the former / the latter (molar ratio) = 1 / 0.4 to 1 / 1.5 Including a hydrogen separation step, using carbon monoxide separated from the synthesis gas (A) in the carboxylic acid production step to produce a carboxylic acid, and hydrogen separated from the synthesis gas (A) to the ammonia production step A production method for producing ammonia by using in a process.   Furthermore, the oxygen separated in the oxygen / nitrogen separation step includes a synthesis gas production step for gasifying coal to produce synthesis gas, and an oxygen / nitrogen separation step for separating nitrogen and oxygen from the air. Is used for coal gasification, and the nitrogen separated in the oxygen / nitrogen separation step is used in the ammonia production step, and the synthesis gas produced in the synthesis gas production step is used as synthesis gas (A). 3. The production method according to 1 or 2.   Furthermore, a shift reaction step for producing hydrogen by shift reaction of the synthesis gas (B) includes hydrogen separated from the synthesis gas (A) in the ammonia production step, and hydrogen obtained by the shift reaction step. The manufacturing method of Claim 2 using.   The production method according to claim 1 or 4, wherein the synthesis gas (A) and the synthesis gas (B) are synthesis gas produced in the same synthesis gas production process.

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