KR102064612B1 - Method and Apparatus for Controlling Moisture Contents in CO2 Refining Process - Google Patents

Abstract

The present invention relates to a method configured to effectively remove moisture contained in a source gas in a carbon dioxide purification process and to stably control a moisture content of the purified gas, and an apparatus therefor. According to the present invention, an apparatus for controlling a moisture content is operated by: a first moisture removal process performed by using a compressor, cooler, and a phase separator capable of controlling the pressure and temperature; and a second moisture removal process which is a filling/adsorption type dry process to remove remaining moisture in the first moisture removal process, wherein a flow of a gas has an upward direction. The moisture removal process performed by using the compressor, the cooler, and the phase separator capable of controlling the pressure and temperature exhibits improved moisture removal efficiency by an increase in the pressure and a drop of a temperature as compared with a conventional carbon dioxide purification process, and the pressure and temperature of a phase separator are controlled so that a moisture content of a gas discharged from the moisture removal process can be constantly maintained in a stable manner.

Description

Method and Apparatus for Controlling Moisture Content in Carbon Dioxide Purification Process {Method and Apparatus for Controlling Moisture Contents in CO2 Refining Process}

The present invention relates to a method and apparatus for stably and efficiently controlling the water content in a purified carbon dioxide final product in a purification process of carbon dioxide for recovering carbon dioxide, which is a by-product of chemical process, as high value added carbon dioxide.

Carbon dioxide has a negative image that affects global warming, but in the gas market, after nitrogen, oxygen and argon, the market is the largest and has various uses and industrial significance. Carbon dioxide is used in industrial fields such as welding, food and beverages such as carbonated beverages and beer, and dry ice for freezing transportation, and also in medical fields requiring strict management.

Conventional purification methods for removing water from carbon dioxide consist of phase separation (primary water removal) by compression / cooling and adsorption (secondary water removal) to remove residual water. The phase separation method by compression / cooling is based on the principle of rising dew point in the thermodynamic concept, which means that the absolute amount of water vaporized in a gas is inversely proportional to pressure and increases with temperature. It is to use the property. That is, as the dew point is increased by compressing the carbon dioxide containing water, and the temperature is increased by cooling, a part of the water contained in the carbon dioxide is condensed and separated / removed. Adsorption method is a method of adsorbing and removing the water molecules diffused into the fine pores on the surface of the adsorbent using a packed adsorption dryer filled with an adsorbent such as activated carbon and activated alumina having excellent water adsorption performance.

As the operating pressure in the primary water removal process by normal compression / cooling is based on the liquefaction process pressure of carbon dioxide, which is the final production process, the operating pressure may change due to the change of the carbon dioxide liquefaction temperature using an ammonia freezer or the like. As the cooling water is used as the cooling water at room temperature, the temperature change of the cooling water at room temperature according to the change of the season is large. According to the change in operating pressure and cooling water temperature, the water content in carbon dioxide, which has undergone the water removal process by compression / cooling, also changes greatly in the range of 300 ~ 700ppmv, and the change in water content in carbon dioxide is the secondary water removal by the subsequent adsorption. The operation cycle in the process has a problem that greatly changes.

The secondary water removal process by adsorption is usually operated in such a way that the two adsorbers are connected in parallel so that adsorption and regeneration proceed at the intersection. The secondary water removal process by adsorption is a case of treating the raw material gas containing a large amount of water as the production efficiency decreases due to the discharge of the purification gas inside the adsorber for regeneration and the energy consumption for the regeneration of the adsorbent is high. It is difficult to use, and has various problems to be improved for optimization such as minimizing the water content of the incoming raw material gas, increasing the contact efficiency of the adsorbent and the raw material gas, improving the adsorption efficiency of the adsorbent.

Recently, additional uses have been developed that require ultra-high purity (> 99.99%) carbon dioxide. Examples of these applications include pharmaceutical / health functional processes using supercritical extraction, supercritical fractions, supercritical chromatography, and semiconductors. Processing (for example, photoresist removal and wafer cleaning), cleaning and drying processes of microelectromechanical systems (MEMS), and the like.

In the case of semiconductor and micro electromechanical system processes, carbon dioxide is used for anti-static cleaning gas in washing with ultrapure water, cleaning and drying solvent with supercritical carbon dioxide, and etching solvent in micro process. The use of ultra-high purity carbon dioxide is essential as micronization and high integration occur. Particularly, in the case of moisture, high value-added products due to residual moisture, such as the change of dielectric constant due to residual moisture, the collapse of fine patterns due to the surface tension generated when the residual moisture is dried, and the occurrence of semiconductor defects due to internal water spots. As the impact on yield and quality increases, it is necessary to develop a process for controlling the moisture content.

Korea Patent Registration 10-1200101

It is an object of the present invention to provide a stable and efficient control method and apparatus for controlling the water content to obtain high value added high-purity carbon dioxide of high industrial value.

One object of the present invention to provide a method and apparatus for improving the water removal efficiency in the carbon dioxide discharged in the primary water removal process using a compression / cooling / phase separator, and also controls the water content constant.

Another object of the present invention is to more efficiently remove the residual moisture in the carbon dioxide discharged from the primary water removal process using a compression / cooling / phase separator in the secondary water removal process using a packed adsorption dryer filled with a moisture adsorbent. To provide a method and apparatus for removal.

The problem to be solved of the present invention is not limited to the above-mentioned problem, and can be variously expanded in a range without departing from the spirit and scope of the present invention.

The present invention relates to a stable and efficient method and apparatus for controlling the moisture content to obtain high value added ultra high purity carbon dioxide, in order to achieve the above object,

In the water content control method of the carbon dioxide purification process,

Water removal process that removes water through the compression, cooling, and phase separation steps, wherein the water removal process controls the pressure by a rear pressure control valve installed in the supply gas outlet of the phase separator and the refrigerant flow rate and / or the refrigerant. Primary moisture removal process, characterized in that for controlling the temperature of the phase separator by temperature control; And

Filled adsorption-type drying process for removing residual moisture that was not removed in the first water removal process, the secondary flow characterized in that the flow of gas flows into the bottom of the filling adsorption dryer to discharge to the top of the dryer Water removal process;

It provides a water content control method in the carbon dioxide purification process comprising a.

The primary water removal process in the present invention

a) compressing the carbon dioxide source gas containing moisture to raise the dew point;

b) a cooling step of condensing moisture by cooling the carbon dioxide source gas containing the water compressed in the compression step;

c) a phase separation step of flash-expanding the compressed and cooled carbon dioxide source gas into a phase separator to separate the condensed water and the condensed water into a carbon dioxide feed gas;

d) in the step c), a pressure control step of controlling the pressure inside the phase separator by a rear pressure control valve installed in the supply gas outlet of the phase separator; And

e) the step c), the temperature control step of controlling the temperature inside the phase separator by the refrigerant flow rate and / or refrigerant temperature control;

It provides a water content control method in the carbon dioxide purification process comprising a.

The secondary water removal process in the present invention

a) a charge adsorption dryer is installed at the rear of the primary water removal process,

b) a flow of gas is injected from the bottom of the packed suction dryer and has an upward flow discharged to the top of the packed suction dryer,

c) alternating two or more packed adsorption dryers connected in parallel, so that when the residual moisture adsorption process is carried out in one (or more) adsorption dryers, the adsorbent regeneration in the other (or more) adsorption adsorption dryers takes place. The present invention provides a method for controlling the residual water content in a carbon dioxide purification process, characterized in that by continuously removing water in an operating manner, continuous operation can be performed without interruption of operation.

In addition, the present invention includes a first moisture removal device and a second water removal device as a water content control device in the carbon dioxide purification process

The primary moisture removal device

a) a compressor for compressing moisture containing carbon dioxide source gas to raise the dew point;

b) a cooler for condensing moisture by cooling the carbon dioxide source gas containing the compressed water in the compressor;

c) a phase separator which flash expands the compressed and cooled carbon dioxide source gas into condensed moisture and the condensed moisture removed carbon dioxide feed gas;

d) a rear pressure regulating valve installed in the gas outlet of the phase separator to discharge gas of excess pressure to the rear while maintaining a constant pressure inside the phase separator; And

e) a temperature control device for controlling the temperature inside the phase separator,

The secondary water removal device is installed at the rear of the primary water removal device, it is characterized in that it comprises two or more connected, the gas adsorption dryer having an internal flow of the upper flow from the bottom to the top It provides a water content control device in the carbon dioxide purification process.

Two or more of the packed adsorption dryers are connected in parallel, and when the residual moisture adsorption process is performed in any one (more than one) adsorption dryer, the regeneration of the adsorbent in the other (more than one) adsorption adsorption dryer is alternately performed. As the water is removed in an operating manner, the present invention provides a moisture content control device in a carbon dioxide purification process, which is a packed adsorption dryer capable of continuous operation without interruption of operation.

Water content control method and apparatus using a compression / cooling / phase separator having a pressure and temperature control function of the present invention, compared to the water removal process using a compression / cooling / phase separator in the conventional carbon dioxide manufacturing process for food and beverage, the water removal efficiency It improves, and has the characteristic to stably and constantly control the water content contained in the purified carbon dioxide.

In the present invention, the pressure control effect in the primary water removal process is provided with a rear pressure control valve at the gas outlet of the phase separator to control the pressure inside the phase separator to be higher than the normal operating pressure (20 atm or less). Thereby, there is an advantage that can increase the water removal efficiency due to the dew point rise. In other words, by installing a rear pressure control valve in the gas outlet of the phase separator to maintain a constant pressure inside the phase separator to discharge the excess gas to the rear, at this time, the control pressure using the rear pressure control valve is conventional operation Controlled to a pressure higher than the pressure, the dew point of the water rises as the pressure inside the phase separator rises, and the amount of water removed from the phase separator increases even when cooled to the normal operating temperature in the cooling step, thereby removing moisture. This is improved.

In addition, the temperature control effect in the primary water removal process of the present invention, by controlling the temperature in the cooling step and the phase separator to a temperature of or below the normal winter temperature by increasing the amount of water removed from the phase separator , Moisture removal efficiency is improved.

In addition, the pressure and temperature control effect in the primary water removal process of the present invention, by controlling the pressure and temperature in the phase separator in a constant manner that the water content in the exhaust gas discharged from the water removal process is kept constant (性) has the effect. That is, since the moisture content of the exhaust gas discharged from the phase separator is influenced only by the pressure and temperature of the phase separator, the discharged water is discharged from the primary water removal process by controlling the temperature at a constant controlled condition. The water content in the gas can be kept stable and constant.

The improvement of water removal efficiency according to the pressure and temperature control of the phase separator in the first water removal process can increase the operating time of the charging and adsorption dryer in the subsequent water removal process. Maintaining the homeostasis of the moisture content in the exhaust gas under pressure and temperature control has the effect of maintaining the operation replacement cycle of the filling adsorption dryer constantly.

The present invention is achieved by configuring a secondary moisture removal process using a packed adsorption dryer for removing residual moisture in the primary moisture removal process.

Filling adsorption dryer of the present invention is characterized in that the flow direction of the carbon dioxide feed gas is injected from the lower end of the charge adsorption dryer to discharge to the top of the charge adsorption dryer, characterized in that it has an upward flow. That is, in a conventional industrial gas treatment process using a packed tower, the flow direction of the gas is injected from the top of the packed tower and has a downward flow direction discharged to the bottom, whereas the present invention has a specific gravity greater than that of air. As the direction is upward, the contact time with the filling adsorbent increases, so that the efficiency of water removal is increased, and even though the residual moisture adsorbed on the adsorbent inside the filling adsorption dryer does not affect the adsorbent performance in the upward direction, There is an effect that can maximize the operating time of the adsorption dryer.

In addition, in the present invention, in installing the filling adsorption dryer, two or more charging adsorption dryers may be connected in parallel. That is, if the moisture content in the carbon dioxide treatment gas discharged by the adsorption and removal of the moisture from the packed adsorption dryer in use exceeds the allowable concentration, the flow direction of the carbon dioxide supply gas is removed by changing the flow direction of the carbon dioxide supply gas to the other adsorption dryers connected in parallel. The process is carried out, and by regenerating the existing charging and adsorption dryer saturated with water in the meantime, there is an effect that the continuous operation without interruption of operation is possible.

1 is a schematic diagram showing a water content control apparatus in a carbon dioxide purification process according to an embodiment of the present invention.

The present invention relates to a method and apparatus for controlling water content in a carbon dioxide purification process using a compression / cooling / phase separator having a pressure and temperature control function, and is flash-expanded to a phase separator after compression and cooling of raw material gas in a primary water removal process. The pressure and temperature of the phase separator separating the condensed water and the condensed water is removed, characterized in that it controls.

In the pressure control of the present invention, a rear pressure control valve is installed at the gas outlet of the phase separator, and the operating pressure is controlled to be higher than the normal operating pressure, thereby maximizing the effect of the dew point and improving the water removal efficiency.

In addition, temperature control improves the water removal efficiency by controlling the phase separator temperature as low as possible within the range higher than the carbon dioxide liquefaction temperature at the selected pressure while maintaining the pressure higher than the normal operating pressure using the rear pressure regulating valve. It is characterized by. At this time, the temperature control in the cooling step and the phase separation step may be performed by the method of controlling the temperature of the refrigerant or the flow rate of the refrigerant, or may be performed by a combination of the two methods. The coolant may use a cooling water, may utilize a coolant used in the liquefaction process of purified carbon dioxide, and may use cold heat generated in various processes such as a low molecular weight component separation process in the carbon dioxide liquefaction process.

In addition, by controlling the pressure and temperature of the phase separator in a constant manner, it is characterized by maintaining a constant water content in the carbon dioxide discharged from the phase separator, that is, subjected to the first moisture removal process. As the content of water contained in the gas discharged from the phase separator depends on the pressure and temperature of the phase separator, by controlling the pressure and temperature constantly, the moisture content in the carbon dioxide discharged from the primary water removal process is stably controlled. Can be.

Another object of the present invention is achieved by removing residual moisture in the primary water removal process through a packed adsorption drying method. The secondary water removal process in which residual moisture is removed is achieved by having a upward flow in which the flow direction of the carbon dioxide feed gas passing through the chuck dryer is injected from the bottom of the chuck dryer and discharged to the top of the chuck dryer. Can be.

In addition, the secondary water removal process and apparatus is characterized in that connecting two or more of the filling adsorption-type dryer is filled with a moisture adsorbent.

Secondary water removal process of the present invention

a) setting an acceptable limit (limit acceptable concentration) of the water content in the purified carbon dioxide purification gas;

b) a filling adsorption drying step of removing residual moisture which was not removed in the first water removal process by using a primary filling adsorption dryer filled with a moisture adsorbent;

c) analyzing the moisture content contained in the carbon dioxide treatment gas from which residual moisture is removed by passing through the packed adsorption drying step;

d) by connecting two or more packed adsorption dryers in parallel further, if the moisture content contained in the analyzed carbon dioxide treatment gas exceeds the limit allowable concentration, the secondary charge adsorption type connected in parallel with the flow direction of the carbon dioxide supply gas. Changing to a dryer direction;

It may include.

In the secondary water removal process of the present invention, the limit allowable concentration of water is preferably 20 ppm or less, and in this case, the carbon dioxide from which water is removed is a food and beverage manufacturing process, a supercritical extraction process, a medical carbonic acid manufacturing process, a pharmaceutical raw material manufacturing process, It can be applied to one or more processes selected from the group consisting of pharmaceutical manufacturing process, nutraceutical raw material manufacturing process, nutraceutical manufacturing process, semiconductor process, electronic component manufacturing process and micro-electromechanical system process.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of a water content control apparatus in a carbon dioxide purification process according to an embodiment of the present invention. As can be seen in Figure 1, the water content control device in the carbon dioxide purification process according to the present invention is a device for treating the raw material gas 11 containing water as the primary moisture removal device 100 and secondary moisture Includes a removal device 200

The primary moisture removing device 100

a) a compressor (10) for compressing moisture-containing carbon dioxide source gas to raise the dew point;

b) a cooler 20 for cooling the carbon dioxide source gas containing the water compressed by the compressor to condense the water;

c) a phase separator 30 for flash-expanding the carbon dioxide source gas containing the compressed and cooled water to separate the condensed water and the carbon dioxide feed gas from which the condensed water is removed;

d) a rear pressure control valve (40) installed in the gas outlet of the phase separator to discharge the excess pressure gas backward while maintaining a constant pressure inside the phase separator; And

e) a temperature control device for controlling the temperature inside said phase separator,

The secondary water removal device 200 is installed at the rear of the primary water removal device, two or more units are connected in parallel, the inside of the gas adsorption adsorption dryer having a flow upward from the bottom to the top ( It provides a water content control device in the carbon dioxide purification process, characterized in that it comprises a 50).

Hereinafter, a method of controlling water content in a carbon dioxide purification process using the apparatus will be described.

Raw Material Gas (11)

In the present invention, the "raw gas 11" refers to carbon dioxide containing water, which flows into the carbon dioxide purification system.

The source gas 11 for use in the recovery and purification of carbon dioxide may include any gas containing carbon dioxide as a main component, and exhaust gas discharged from a combustion process such as a thermal power plant or an incinerator; By-product gas discharged from cement, steel mill, etc .; By-product gas in the fermentation process; In addition, it may be a by-product gas generated after synthesis / purification reaction of raw materials required in the fertilizer process, chemical and petrochemical industries, etc., and a pretreatment process including removing particulate matter, sulfur compounds, organic compounds, etc. from these exhaust gases and by-product gases. It may be rough. However, as the object of the present invention is limited to the method for removing water, hydrogen is produced from syngas, which is a gasification reaction product used as a raw material in a conventional carbon dioxide purification process for food and beverages having a relatively low content of impurities other than water. It is preferred to use byproducts of the hydrogen production process.

Primary moisture removal device using compression / cooling / phase separator (100)

In the first aspect of the present invention, the primary water removal device 100 using the compressor 10, the cooler 20 and the phase separator 30 capable of pressure and temperature control is the rear pressure control behind the phase separator 30. The valve 40 is mounted to constantly control the pressure inside the phase separator 30, and the temperature inside the phase separator 30 is controlled using a temperature control device.

The primary water removal apparatus 100 using the compression / cooling / phase separator is composed of a compressor 10, a cooler 20, and a phase separator 30 arranged in series as shown in FIG. 1. In addition, in FIG. 1, only the brower 1, the cooler 20, the phase separator 30 and the compressor 10, the cooler 20, and the phase separator 30 for inflow of source gas are illustrated for simplicity. The number of unit processes actually used may be omitted in the brower 1 in accordance with the pressure of the incoming raw gas, one or more compressors 10, respectively, depending on the capacity of the compressor 10 and the cooler 20 , Coolers 20 and phase separators 30.

According to FIG. 1, as the source gas 11 is compressed by the compressor 10, the dew point temperature of moisture contained in the source gas 11 is increased, and the temperature of the source gas compressed in the cooler 20 is decreased. As a result, some of the moisture contained in the source gas is condensed. When the compressed and cooled source gas condensed with a portion of the water is flash-expanded to the phase separator 30, the condensed water is collected at the bottom of the phase separator and separated from the supply gas 22 from which the condensed water is removed. The condensed water is collected at the bottom of the phase separator and discharged through a water discharge valve (not shown), and the supply gas 22 is discharged through the top of the phase separator 30.

A rear pressure control valve 40 is mounted at the outlet of the supply gas 22 at the top of the phase separator 30 to control the pressure of the phase separator 30.

On the other hand, the temperature inside the phase separator 30 is controlled using a temperature control device. As the temperature control device, a general-purpose cooling device using a coolant such as cooling water or ammonia may be used, and cooling heat generated in a carbon dioxide purification step and a liquefaction step may be used.

Compressor (10)

In the primary water removal apparatus 100 using a compression / cooling / phase separator, any suitable compressor 10 may be used according to the inlet pressure and the compression purpose of the source gas. Low pressure compressors for smooth inlet and compression of gases and high pressure compressors for compression to the pressures required in the compression process are used.

For example, when the raw material gas is introduced at a relatively low pressure, it may be compressed to 1.2 atm to 2.0 atm using a broor or the like, and then pressurized using a compressor such as a compressor, a multistage compressor, a reciprocating compressor, and a gas booster. Can be compressed.

The pressure of the phase separator 30 in the final stage using the compressor is not less than 20 atm, which is the operating pressure of a conventional carbon dioxide refining process, and not more than 73 atm, which is the critical pressure of carbon dioxide, in consideration of the moisture content in the exhaust gas, the liquefaction conditions of the carbon dioxide, and the like. The pressure of the phase separator 30 in the intermediate stage is selected in the pressure range, and the number of compression stages and the compression pressures are selected in consideration of the inlet pressure of the raw material gas and an optimal compression stage design method in a conventional multistage compression process. do. That is, the present invention is characterized in that the water removal process using the compression / cooling / phase separator as a set can be performed in a plurality of stages, in which case the pressure of the compressor of the rear stage is increased compared to the pressure of the compressor of the front stage. That is, the primary water removal process of the present invention is characterized in that the compression step, the cooling step and the phase separation step are repeated one or more times, wherein the pressure in the post compression step is equal to or greater than the pressure in the shear compression step.

That is, when the fluid is pressurized by the same pressure range, the operating cost can be reduced as the multi-stage compression process requires less power than the single-stage compression process. The optimum number of compression stages and the operating conditions are determined to minimize the cost of operation. For example, an empirical design method of determining the number of compression stages by applying a compression ratio in a range of 2 to 3 in one stage may be applied.A method of applying the same compression ratio in each stage after determining the number of compression stages may be applied. May apply.

Chiller (20)

In the inlet and multi-stage compression process of the source gas 11, in each compression step, a process of cooling the compressed gas for removing the heat of compression and condensation of moisture in the phase separator 30 is performed. The cooling apparatus of can be used. For example, a method of controlling the coolant flow rate, a method of controlling the temperature of the coolant using the refrigerating unit, and a method of simultaneously controlling the coolant temperature and the flow rate may be used, and a refrigerant such as ammonia used in the liquefaction process of purified carbon dioxide may be used. In addition, a low molecular weight cold heat gas removed from the liquefied carbon dioxide may be used, or cold heat generated in various processes may be used.

In order to condense the water contained in the source gas 11 to the maximum, it is preferable to select the cooling temperature of the compressed gas as low as possible, but the carbon dioxide is liquefied in the phase separator 30 and discharged together with the condensed water. In order to prevent the control unit 10 to maintain a temperature higher than the liquefaction temperature of carbon dioxide at the pressure condition selected by the compressor 10.

Phase Separator (30)

In the phase separator 30, the compressed and cooled raw material gas 11 is flash-expanded to be separated into condensed water and the supply gas 22 from which the condensed water is removed, and each compression / cooling process is performed according to the configuration of the compression / cooling process. It should be installed behind the cooling stage. Water condensed and separated from the phase separator 30 is collected at the bottom of the phase separator 30 and discharged through a discharge valve, and the supply gas 22 from which the condensed water is separated is discharged to the top of the phase separator.

In the present invention, the internal pressure of the final stage phase separator 30 controlled by the rear pressure regulating valve is preferably selected within a range of 73 atmospheres or less, which is a critical pressure of carbon dioxide at 20 atmospheres or more, and the temperature inside the phase separator 30. The carbon dioxide must be separated from the condensed water by maintaining the gas phase by selecting a temperature above the carbon dioxide liquefaction temperature at the selected pressure condition in the range of -19 ° C or above and the critical temperature of carbon dioxide below 37 ° C.

The phase separator of the present invention is capable of temperature control by having a temperature control device for controlling the internal temperature.

Rear pressure regulating valve (40)

The present invention uses a pressure control device of the rear pressure control valve 40 in the discharge portion of the supply gas 22 above the phase separator 30 to control the pressure of the phase separator 30. The pressure control is equipped with a rear pressure control valve 40 in the gas discharge portion discharged from the phase separator of the phase separation step to discharge the gas of excess pressure to the rear while maintaining a constant internal pressure of the phase separator 30. Is done.

The present invention provides a gas for smooth gas intake of the rear compressor (10) between the front rear pressure control valve (40) and the rear compressor (10) when the water removal process using the compression / cooling / phase separator is performed in a plurality of stages. A reservoir (not shown) can be installed.

The temperature and pressure control device of the phase separator 30 for controlling the water content of the feed gas 22 may be applied only to the final phase separation step before being introduced into the secondary water removing device 200 including a packed adsorption drying process. However, it is preferable to apply to at least one phase separation step, and more preferably to all phase separator steps for stable and efficient control of residual moisture.

Supply gas (22)

In the present invention, the "supply gas" 22 means that a part of the water contained in the source gas 11 is removed by passing through the primary water removing apparatus 100 using at least one compression / cooling / phase separator. , Carbon dioxide introduced into the secondary water removal apparatus 200 including an adsorption-type drying process.

The moisture content of the feed gas 22 depends only on the temperature and pressure of the phase separator 30 in the final stage of the primary water removal apparatus 100, and as the temperature and pressure of the phase separator 30 in the final stage is determined. The moisture content in the feed gas is determined.

Secondary moisture removal device 200 including a packed adsorption drying process

In another aspect of the present invention, a secondary moisture removal device 200 including a packed adsorption-drying process to remove residual moisture not removed in the primary moisture removal device 100 using a compression / cooling / phase separator is included. The filling adsorption drying process is performed through the flow of the supply gas 22 passing through the charging adsorption dryer 50 filled with the moisture adsorbent as shown in FIG. 1.

Secondary water removal device 200 of the present invention comprises two or more of the adsorption-type dryer 50

a) setting an acceptable limit (limit acceptable concentration) of the water content in the purified carbon dioxide treating gas;

b) a filling adsorption drying step of removing residual moisture which was not removed in the primary water removal process by using a primary filling adsorption dryer (50A) filled with a moisture adsorbent;

c) analyzing the moisture content contained in the carbon dioxide treatment gas from which residual moisture is removed by passing through the packed adsorption drying step;

d) by connecting two or more packed adsorption dryers in parallel, if the moisture content contained in the analyzed carbon dioxide treatment gas exceeds the limit allowable concentration, the secondary charge adsorption type connected in parallel with the flow direction of the carbon dioxide supply gas. Replacing in the direction of the dryer 50B;

e) regenerating the primary packed adsorption dryer (50A) saturated with water while removing residual moisture using the secondary packed adsorption dryer (50B);

Can be performed.

At this time, the present invention is characterized in that the feed gas 22 is introduced from the lower end of the filling adsorption type dryer 50 has an upward flow discharged to the upper end of the filling adsorption type dryer (50). In the industrial gas treatment process using a conventional packing tower, the flow direction of the gas is injected from the top of the filling tower and has a downward flow direction discharged to the bottom, whereas the upward gas flow in the present invention has a specific gravity of air. When applied to larger carbon dioxide, the contact time with the packed adsorbent is increased to improve the efficiency of water removal, and even if the residual moisture adsorbed on the adsorbent inside the adsorption dryer 50 is condensed, the adsorbent performance in the upward direction is not affected. Since there is an advantage that can maximize the operating time of the charging and adsorption dryer (50).

As shown in FIG. 1, in the secondary water removing apparatus 200, two or more filling adsorption dryers 50 filled with a moisture adsorbent are connected in parallel, and supply gas from any one of the adsorption adsorption dryers 50A. When the residual moisture adsorption process in (22) is performed, the regeneration of the adsorbent is performed in the other packed adsorption dryer 50B, and the adsorption process of the residual water in the feed gas 22 is performed in the packed adsorption dryer 50B. By removing the moisture in the carbon dioxide supply gas 22 in an alternate operation method in which the regeneration of the adsorbent is performed in the other filling adsorption dryer 50A, continuous operation may be performed without interruption of operation.

According to FIG. 1, the two adsorption-packed adsorption dryers 50 filled with moisture adsorbents are connected in parallel, but the adsorption-sorption dryers 50 filled with the water adsorbent have a flow rate of the supply gas 22, a supply gas ( 22) Two or more units may be configured in parallel depending on conditions such as internal moisture content, adsorption capacity and regeneration time of the moisture adsorbent, and limit allowable concentration of moisture in the process gas 33.

A moisture analyzer for measuring the moisture content of the carbon dioxide treatment gas that has undergone the packed adsorption drying process is installed behind the packed adsorption drying process so that the analysis of the water content can be performed in real time on-line.

Purified Gases (33)

In the present invention, the "refined gas" 33 refers to a final product having a water content lowered below a predetermined limit allowable concentration as it passes through a secondary moisture removal device 200 including a packed adsorption drying process. It is called.

Purification gas 33 of the present invention is a food and beverage manufacturing process, supercritical extraction process, medical carbonic acid manufacturing process, pharmaceutical raw materials, pharmaceutical products, health functional food raw materials or health functional food manufacturing process, semiconductor process, electronic component manufacturing process and microelectronics It may be applied to one or more processes selected from the group consisting of system processes.

In the International Standard for Food and Drink (ISBT), the allowable concentration of purified gas is 20 ppmV, and the supercritical extraction process, the supercritical cleaning process in the semiconductor process, and the ultra-precision electromechanical system ( In the MEMs) process, the moisture content of the refinery gas is required to be 1 ppm or less.

Purified gas 33 subjected to the first and second water removal process of the present invention has a limit allowable concentration of 20 ppm or less, preferably a limit allowable concentration of 5 ppm or less, and more preferably a limit of moisture. It is characterized by the allowable concentration being 1 ppm or less.

Example

Hereinafter, the effects of the method and apparatus for controlling water content in the carbon dioxide purification process provided by the present invention will be described in detail with reference to a preferred embodiment.

Comparative Example : Water removal process by compression / cooling in a conventional carbon dioxide manufacturing process

In order to explain the effect of the first aspect of the present invention, the first water removal process, that is, the water removal process using a compression / cooling / phase separator capable of pressure and temperature control, compression / cooling in a conventional carbon dioxide manufacturing process for food and beverage The water removal process using the / phase separator was selected as a comparative example.

Water removal process using a compression / cooling / phase separator in a conventional carbon dioxide manufacturing process for food and beverage is pressure and temperature control function is excluded from the water removal process using a compression / cooling / phase separator capable of pressure and temperature control in the present invention As a process, it was selected as a standard for explaining the effect of improving the water removal efficiency and the stable control effect of the water contained in the present invention to be described in the future pressure and temperature control.

Water removal process using a compression / cooling / phase separator in the conventional carbon dioxide manufacturing process for food and beverages comprises a suction step consisting of a blower, a cooler, a phase separator for the introduction of source gas;

A primary compression step consisting of a compressor, a cooler and a phase separator for primary compression of the sucked raw material gas; And

It consists of a secondary compression step consisting of a compressor, a cooler, and a phase separator for compressing the primary compressed raw material gas to a normal operating pressure.

The pressure in the suction stage of the raw material gas using the brower is usually operated at 1.2 to 1.5 atmospheres, the pressure in the primary compression stage is about 5 atm, and the pressure in the final stage secondary compression stage is the product liquid carbon dioxide. It is selected around 20 atm slightly higher than the storage tank pressure.

Cooling in the cooling step after the compression step usually uses room temperature as the cooling water, the phase separator is only a device for the separation of condensed water, temperature control is not performed. In the cooling step using the cooling water at room temperature, there is a problem that the cooling water temperature variation in winter and summer is large. That is, the cooling water at room temperature may have a temperature of 10 ° C. or less in winter, and more than 20 ° C. in summer. The temperature difference in the cooling stage occurs due to the cooling water temperature difference, and the temperature difference in the cooling stage greatly affects the moisture content in the exhaust gas.

In order to demonstrate the change in moisture content according to the change in the cooling water temperature, the water content in the exhaust gas discharged from the phase separator and the operating conditions of each stage in the conventional carbon dioxide manufacturing process for food and beverage was performed, and the calculation results are shown in [Table 1]. Shown in In order to simplify the calculation, it is assumed that the source gas contains only two components, moisture and carbon dioxide, and the moisture content is converted from the dew point under pressure to the dew point under atmospheric pressure and the volume fraction conversion at the converted dew point under atmospheric pressure. .

Suction Stage Primary compression step Secondary compression step pressure
(atmospheric pressure) 1.2 5 20 Temperature
(℃) 10 15 20 10 15 20 10 15 20 Water content
(ppmV) 10,130 14,136 19,495 1,805 2,632 3,791 318 463 666

As can be seen in Table 1, it can be seen that the water content of the exhaust gas increases as the temperature in the cooling stage increases under the same pressure conditions, and the temperature in the cooling stage rises from 10 ° C. to 20 ° C. Therefore, it can be seen that the exhaust gas under the same pressure condition has an increase of approximately 2 times the moisture content.

This change in moisture content in the exhaust gas affects the subsequent adsorption-and-dry drying process, which has a disadvantage in that the dryer capacity increases according to the maximum moisture content condition in the dryer design, and the moisture content increases beyond the design condition. If the moisture content in the treated gas through the filling adsorption drying process may not be processed below the limit allowable concentration may occur, there is a problem such that the replacement cycle of the dryer is changed according to the change in moisture content according to the season.

Example 1 Selection of Phase Separator Pressure and Temperature Range

In the present invention, the water removal process using the compression / cooling / phase separator capable of controlling pressure and temperature, that is, the first water removal process, controls the pressure at a higher pressure than the water removal process of the conventional carbon dioxide purification process, and maintains a constant temperature. Control features.

If the pressure is maintained higher than the normal operating pressure, the water removal efficiency can be improved by the condensation effect of the dew point of the water, but the carbon dioxide is also condensed and condensed and separated from the phase separator as the liquefaction temperature increases. It can be discharged together and the recovery rate can be reduced. Therefore, appropriate pressure and temperature conditions should be selected to facilitate the separation of carbon dioxide from condensation and separated water.

In the present invention, the pressure condition of the phase separator was limited to a range of not less than 73 atmospheres, which is a critical pressure of carbon dioxide, at a pressure of 20 atmospheres or more, which is an operating pressure in a conventional carbon dioxide manufacturing process for food and beverages, and the temperature range does not liquefy carbon dioxide at the pressure. It was selected as a temperature range where the moisture is condensed as much as possible under the condition of maintaining the gas phase, that is, above the carbon dioxide liquefaction temperature at the corresponding pressure.

Table 2 shows the carbon dioxide liquefaction temperature at typical pressure conditions.

Pressure (atmospheric pressure) 20 30 40 50 60 70 Temperature (℃) -19.1 -5.1 5.8 14.8 22.5 29.3

Example 2 Pressure Control in a Water Removal Process Using Compression / Cooling / Phase Separators

In the first water removal process of the present invention, that is, the water removal process using a compression / cooling / phase separator capable of pressure and temperature control, the effect of the phase separator pressure control will be described.

The effect of the phase separator pressure control is to improve the water removal efficiency by using the dew point temperature rise effect of the moisture as the phase separator pressure increases, the control of the phase separator pressure is discharged from the phase separator and flows into the charge adsorption dryer, It was controlled by mounting a rear pressure regulator on the outlet of the phase separator.

In order to explain the effect of improving the water removal efficiency by the pressure control, while increasing the pressure in units of 10 atm within the range of 73 atm, which is the critical pressure of carbon dioxide, based on 20 atm, which is the operating pressure of a conventional carbon dioxide purification process. The moisture content in the off-gas at elevated pressure was calculated and compared.

The calculation method assumes the source gas as a two-component system of water and carbon dioxide in the same manner as the water content calculation in the conventional food and beverage carbon dioxide manufacturing process in Example 1, the water content calculation is the dew point under atmospheric pressure of the dew point under pressure. A volume fraction conversion method at and a converted dew point under atmospheric pressure was used. However, in the water removal process using the compression / cooling / phase separator of conventional carbon dioxide for food and beverage, the water content in the exhaust gas at each stage was shown, but the feed gas supplied to the packed adsorption drying apparatus through the compression / cooling / phase separator was As the moisture content depends on the temperature and pressure of the phase separator in the final stage, the results of the calculations showed only the moisture content in the feed gas exiting at the temperature and pressure conditions of the phase separator in the final stage.

In order to exclude the influence of temperature on the water removal efficiency, the temperature was kept constant, and the phase separator temperature was set at 10 ° C. for the winter coolant temperature and 20 ° C. for the summer coolant temperature, and a coolant temperature of 15 ° C., which is the median value. Was set to calculate the moisture content of the moisture content in the feed gas discharged from the phase separator according to the pressure rise at the same temperature.

The calculation results when the phase separator temperature was maintained at 10 ° C. are shown in [Table 3]. When the temperature of the phase separator was 10 ° C., when the pressure was 50 atm or higher, the pressure range was estimated only to 40 atm as the carbon dioxide was liquefied.

pressure
(atmospheric pressure) 20 30 40 Water content
(ppmV) 318 191 133

The calculation results when the phase separator temperature is kept at 15 ° C. are shown in [Table 4], and the calculation results when the phase separator temperature is kept at 20 ° C. are shown in [Table 5]. When the phase separator temperature is 15 ° C., when the pressure exceeds 50 atm, when the phase separator temperature is 20 ° C., and when the pressure is 60 atm or more, the pressure range was calculated only to 50 atm as the carbon dioxide was liquefied.

pressure
(atmospheric pressure) 20 30 40 50 Water content
(ppmV) 463 278 194 146

pressure
(atmospheric pressure) 20 30 40 50 Water content
(ppmV) 666 401 280 211

As can be seen from the above calculation result table, the moisture content in the exhaust gas is about 40%, 40 when the pressure rises to 30 atm, compared to 20 atm where the pressure is the operating pressure of a conventional carbon dioxide purification process at all estimated temperature conditions. It is about 58% lower when the pressure rises, and about 68% when the pressure increases.

As a result, the available operating time of the back-packed adsorption dryer installed by the pressure control in the primary water removal process using the compression / cooling / phase separator having pressure and temperature control function was about 1.7. ~ 3.2 times more effective.

In the case of further increasing the phase separator pressure to 60 atm and 70 atm using the rear pressure regulating valve, the calculated moisture content in the exhaust gas is shown in [Table 6]. As shown in Example 1, when the phase separator pressure is 60 atm, the liquefaction temperature of carbon dioxide is 22.5 ° C., and when the phase separator pressure is 70 atm, the carbon dioxide liquefaction temperature is 29.3 ° C. The separator temperature was calculated at 25 ° C., and the phase separator temperature was estimated at 30 ° C. when the phase separator pressure was 70 atm.

pressure
(atmospheric pressure) 60 70 Temperature
(℃) 25 30 Water content
(ppmV) 239 277

When the phase separator pressure is controlled to 60 atm, the water content of the exhaust gas is reduced by about 64% compared to 20 at 20 ° C. and 25% at 20 at 10 ° C. even at a temperature of 25 ° C., and the pressure at the phase separator is 70 atm. In addition, the water content of the exhaust gas of about 58% compared to 20 atm 20 ° C and about 13% at 20 atm 10 ° C is reduced at a temperature of 30 ° C.

Example 3 Temperature Control in a Water Removal Process Using Compression / Cooling / Phase Separators

In the first water removal process of the present invention, that is, the water removal process using a compression / cooling / phase separator capable of pressure and temperature control, the effect of the phase separator temperature control will be described.

The effect of the phase separator temperature control is to lower the phase separator temperature below the dew point temperature of the water at the corresponding pressure to improve the water removal efficiency. The lower the phase separator temperature, the better the water removal efficiency is used. However, the phase separator temperature should be controlled higher than the carbon dioxide liquefaction temperature at the pressure as described in Example 1.

Conventional cooling devices may be used for the cooling of the compressed gas and the phase separator temperature control steps. For example, a method of controlling the coolant flow rate, a method of controlling the temperature of the coolant using the refrigerating unit, and a method of simultaneously controlling the coolant temperature and the flow rate may be used, and a refrigerant such as ammonia used in the liquefaction process of purified carbon dioxide may be used. In addition, a low molecular weight cold heat gas removed from the liquefied carbon dioxide may be used, or cold heat generated in various processes may be used.

The effect of improving the water removal efficiency by temperature control is to calculate the water content in the exhaust gas at the phase separator temperatures of 10 ° C., 15 ° C. and 20 ° C. when the phase separator pressure is kept constant to exclude the influence of pressure. Explain. As the calculation method, the same method as in Comparative Example and Example 2 was used, and in the case of the phase separator pressure of 20 atm in [Table 7], the phase separator in the case of 30 atm of the pressure of the phase separator in [Table 8]. Table 10 shows the results of calculating the water content of the exhaust gas when the pressure of 40 atm and the pressure of the phase separator are 50.

Temperature
(℃) 10 15 20 Water content
(ppmV) 318 463 666

Temperature
(℃) 10 15 20 Water content
(ppmV) 191 278 401

Temperature
(℃) 10 15 20 Water content
(ppmV) 133 194 280

Temperature
(℃) 10 15 20 Water content
(ppmV) - 146 211

As shown in [Table 7] to [Table 10], in all the conditions of controlling the phase separator pressure to 20 atm, 30 atm and 40 atm, by controlling the phase separator temperature from 20 ° C to 10 ° C, The water content is reduced by about 52% or more, and under the conditions of controlling the phase separator pressure to 20, 30, 40 and 50 atmospheres, even when the phase separator temperature is controlled to 15 ° C, the phase separator temperature is 20 ° C. It can be seen that the water content in the exhaust gas is reduced by about 30% or more.

However, in the present embodiment, the lower limit of the phase separator temperature was performed only up to 10 ° C. for comparison with the comparative example. However, in the case of maintaining the condition above the carbon dioxide liquefaction temperature, the lower temperature range may be applied to increase the water removal efficiency. have.

Example 4 Pressure and Temperature Control in Water Removal Process Using Compression / Cooling / Phase Separator

In the first water removal process of the present invention, that is, the water removal process using a compression / cooling / phase separator capable of pressure and temperature control, the effects of the phase separator pressure and temperature control will be described.

Effects of the phase separator pressure and temperature control can simultaneously achieve the effect of improving the water removal efficiency due to the pressure rise described in Examples 2 and 3 and the effect of improving the water removal efficiency due to the temperature drop, and in addition to the phase separator By constantly controlling the pressure and temperature, there is an effect that the water content in the feed gas discharged from the phase separator can be stably maintained. That is, the content of water contained in the feed gas discharged from the phase separator depends only on the two properties, the phase separator pressure and temperature, and when the phase separator pressure and temperature are set, the water content contained in the feed gas corresponds to the conditions. Is kept constant.

Table 11 shows the moisture content of the exhaust gas according to the phase separator pressure and temperature conditions.

Pressure (atmospheric pressure)
Temperature (℃) 20 30 40 50 60 70 10 318 191 133 - - - 15 463 278 194 146 - - 20 666 401 280 211 - - 25 - - - - 239 - 30 - - - - - 277

The effect of the phase separator pressure and temperature control is to remove the secondary water, which is installed at the rear and removes residual moisture that was not removed in the primary water removal process by the effect of improving the water removal efficiency due to the pressure rise and the temperature drop. It is possible to obtain an effect of increasing the operating time of the adsorption-type dryer in the process, and the adsorption-sorption type in the secondary water removal process installed at the rear by the effect that the moisture content contained in the feed gas discharged from the phase separator is kept constant. It also has the effect of maintaining a constant replacement cycle of the dryer.

Example 5 Packed Adsorption Drying Process to Remove Residual Water

Another feature of the moisture control process to be solved in the present invention is the filling of the moisture adsorbent filled with a secondary moisture removal process for the removal of residual moisture not removed in the primary water removal process using the compression / cooling / phase separator The adsorption drying process is further configured.

As described in the above embodiments, in the first water removal process of the present invention, that is, the water removal step using a compression / cooling / phase separator capable of pressure and temperature control, the water removal efficiency is increased by the effect of pressure rise and temperature drop. The water content of the feed gas at 40 atm and 10 ° C. showing the best water removal efficiency is 133 ppmV, which is much higher than 20ppmv of the ISBT standard, which is an international standard for carbon dioxide for food and beverages. In order to apply to the ultra-high purity carbon dioxide utilization process, such as the process it is necessary to install a packed adsorption drying process to remove residual moisture.

In the present invention, the secondary water removal process, that is, the adsorption adsorption-type drying process filled with the moisture adsorbent, has a flow direction in which the flow direction of the feed gas flowing through the dryer flows from the bottom of the dryer to the top of the dryer and flows out to the top of the dryer. It is done. In addition, the filling adsorption drying process is capable of removing the water content in the initial processing gas at a level of 1 ppbV or less, and after adsorbing a certain amount of water, the adsorption performance is deteriorated to gradually increase the water content in the processing gas. Then, when the water content reaches the adsorption limit value, the water content increases rapidly and the water content in the process gas is allowed to be limited by setting the limit allowable concentration when the water content suitable for the process gas purpose to be used is reached. When the concentration is reached, the gas flow is changed in the direction of the other connected adsorption dryers connected in parallel, and then the regeneration operation for reuse of the water-saturated charging adsorber is performed while the replaced adsorption dryer performs the drying operation. do.

In the present invention, the secondary water removal process, that is, the gas flow direction, which is a characteristic of the adsorption adsorption drying process in which the moisture adsorbent is filled, has an upward flow flowing into the lower end of the adsorption adsorption dryer and discharged to the upper end of the dryer, is carbon dioxide. Unlike other industrial gases, as the specific gravity is greater than that of air, the flow of the upward direction has an effect of improving the water removal efficiency as the contact time with the adsorbent increases. In addition, as the adsorption and condensation of water starts from the lower adsorbent and proceeds to the upper direction, there is an advantage that the performance of the adsorption filler can be stably maintained since the influence of the condensed water does not affect the upper adsorbent.

Example 6 Water Content Control Composed of Primary Water Removal Process and Secondary Water Removal Process

The water content control process in the carbon dioxide purification process consisting of the first and second water removal process in the present invention is characterized in that the first water removal process, that is, compression / cooling / phase separator capable of pressure and temperature control As the secondary moisture removal process, which is the filling adsorption drying process, is installed at the rear of the used water removal process, there is an effect that the operation time of the charging adsorption type dryer increases by the effect of improving the water removal efficiency in the primary moisture removal process. It is to have the effect that the replacement cycle of the filling adsorption-type dryer by the homeostasis effect that the moisture content in the feed gas of the secondary moisture removal process is kept constant.

Operation of the back-packed adsorption-type drying apparatus according to the improvement of the water removal efficiency of the water removal process using the water content control method and apparatus using a compression / cooling / phase separator having a primary water removal process, pressure and temperature control function in the present invention Explain the effect of increasing the period.

Based on a 10-day replacement cycle for a packed adsorption dryer that processes 100 tons of feed gas per day at 20 atmospheres at 20 ° C, which is a summer operating condition in a conventional carbon dioxide purification process without pressure and temperature control. The change of operating cycle according to the pressure and temperature control effect when the same packed adsorption-type drying device was used was calculated and compared.

The water content in the feed gas at the phase separator pressure of 20 atm and the phase separator temperature of 20 ° C. selected as a standard is 666 ppmV as shown in [Table 5], [Table 7] and [Table 11]. 272.6 ppm wt. For the convenience of calculation, it is assumed that the purified gas passed through the packed adsorption drying apparatus does not contain moisture because all the moisture is absorbed. As the feed gas throughput is estimated to be 100 tonnes / day, the daily absorption in the packed adsorption dryer is 27.26 kg, and the maximum moisture absorption of the packed adsorption dryer is 272.6 kg based on the 10-day cycle.

Under the assumption that the same packed adsorption dryer is used, the maximum adsorption capacity of the adsorption dryer is 272.6 kg, which has the same value, and is calculated from the moisture content in the feed gas according to the phase separator pressure and temperature shown in [Table 11]. Calculation results of the replacement cycle of the dryer are shown in [Table 12].

Pressure (atmospheric pressure)
Temperature (℃) 20 30 40 50 60 70 10 20.9 34.9 50.1 - - - 15 14.4 24.0 34.3 45.6 - - 20 10.0 16.6 23.8 31.6 - - 25 - - - - 27.9 - 30 - - - - - 24.0

As shown in [Table 12], when the phase separator pressure was increased to 30 atm versus 20 at all conditions of 10 ° C., 15 ° C., and 20 ° C. by the effect of improving the water removal efficiency according to the pressure rise of the phase separator, The use cycle of the adsorption dryer increased 1.7 times, and the use cycle of the suction adsorption dryer of 3.2 times increased when the pressure increased to 40 atm and 2.4 times at 50 atm. In addition, when the temperature was lowered to 15 ° C. compared to 20 ° C. in all conditions of 20 atm, 30 atm, 40 atm and 50 atm due to the effect of improving the water removal efficiency by the phase separator temperature drop, 1.4 times, 10 When the temperature is lowered to ℃, the usage cycle of the 2.1 times charge adsorption dryer is increased. In addition, in the case of controlling the phase separator pressure at 40 atm and the temperature at 10 ° C., the standard phase separator pressure at 20 atm and the temperature at 20 ° C. are used to improve the water removal efficiency due to the pressure rise and the temperature drop. Compared with the increase of the maximum use cycle, which is 5 times.

From the above results, it is possible to confirm the effect of increasing the use cycle of the adsorption adsorption dryer installed at the rear by improving the water removal efficiency under the control of the pressure and temperature of the phase separator. It is possible to reduce the production loss due to the discharge of the production gas inside the packed adsorption dryer for replacement and regeneration, and to reduce the energy cost required for the regeneration of the dryer.

In addition, another feature of the present invention is to maintain a constant moisture content in the feed gas discharged from the phase separator by constantly controlling the phase separator temperature, designing the dryer on the optimum scale in the subsequent filling adsorption drying process In addition, the effect of maintaining the dryer replacement cycle is constant. That is, if the phase separator pressure and temperature conditions are selected as shown in [Table 12], there is an effect that the operation can be performed at a constant replacement cycle according to the calculated replacement cycle of the packed adsorption dryer.

11 source gas 22 feed gas 33 refinery gas
1: broo 10: compressor 20: cooler
30: phase separator 40: rear pressure control valve 50: filling adsorption dryer
100: primary moisture removal device 200: secondary moisture removal device

Claims (12)

delete In the water content control method of the carbon dioxide purification process,
Water removal process that removes water through the compression, cooling, and phase separation steps, wherein the water removal process controls the pressure by a rear pressure control valve installed in the supply gas outlet of the phase separator and the refrigerant flow rate and / or the refrigerant. Primary moisture removal process, characterized in that for controlling the temperature of the phase separator by temperature control; And
Filled adsorption-type drying process for removing residual moisture that is not removed in the primary water removal process, the secondary water removal characterized in that the flow of gas flows into the lower end of the dryer and discharged to the top of the dryer Method of controlling the water content in the carbon dioxide purification process comprising a step,
The first moisture removal process
a) compressing the carbon dioxide source gas containing moisture to raise the dew point;
b) a cooling step of condensing moisture by cooling the carbon dioxide source gas containing the water compressed in the compression step;
c) a phase separation step of flash-expanding the compressed and cooled carbon dioxide source gas into a phase separator to separate the condensed water and the condensed water into a carbon dioxide feed gas;
d) in the step c), a pressure control step of controlling the pressure inside the phase separator by a rear pressure control valve installed in the supply gas outlet of the phase separator; And
e) the step c), the temperature control step of controlling the temperature inside the phase separator by the refrigerant flow rate and / or refrigerant temperature control;
Water content control method in the carbon dioxide purification process comprising a The method of claim 2, wherein the first water removal process, the compression step, the cooling step and the phase separation step is repeated one or more times, wherein the pressure of the post-stage compression step is the water content control in the carbon dioxide purification process is the pressure or more than the pressure of the shear compression step Way 3. The method of claim 2, wherein the internal pressure control of the phase separator by the rear pressure regulating valve discharges excess gas to the rear while maintaining a constant internal pressure of the phase separator. The method of controlling moisture content in a carbon dioxide purification process according to claim 3, further comprising a gas reservoir for smooth gas intake between the front rear pressure control valve and the rear compression stage. The phase separator internal pressure of the final stage of the first water removal process is selected in the range of 73 atm or less, which is the critical pressure of carbon dioxide at 20 or more, and the internal temperature of the phase separator is -19 ° C or higher. A method of controlling water content in a carbon dioxide purification process selected at a temperature higher than a carbon dioxide liquefaction temperature at a predetermined pressure condition in which carbon dioxide is present in a gaseous phase within a critical temperature of 37 ° C. or lower. The method of claim 2, wherein the secondary water removal process is a packed adsorption drying process, the flow of the gas flows from the bottom of the filling adsorption dryer filled with the moisture adsorbent and has an upward flow discharged to the top of the adsorption adsorption dryer Water content control method in the carbon dioxide purification process, characterized in that The method of claim 7, wherein the secondary water removal process
a) setting an acceptable limit (limit acceptable concentration) of the water content in the purified carbon dioxide purification gas;
b) a packed adsorption drying step of removing residual moisture which was not removed in the first water removal process by using a primary packed adsorption dryer filled with a moisture adsorbent;
c) analyzing the moisture content contained in the carbon dioxide treatment gas from which residual moisture is removed by passing through the packed adsorption drying step;
d) by connecting two or more packed adsorption dryers in parallel further, if the moisture content contained in the analyzed carbon dioxide treatment gas exceeds the limit allowable concentration, the secondary charge adsorption type connected in parallel with the flow direction of the carbon dioxide supply gas. Changing to a dryer direction;
Water content control method in the carbon dioxide purification process comprising a The method of claim 7, wherein the secondary water removal process is a carbon dioxide purification process in which a limit allowable concentration of water is 20 ppm or less. The method of claim 2, wherein the carbon dioxide from which water is removed is a food and beverage manufacturing process, a supercritical extraction process, a medical carbonic acid manufacturing process, a pharmaceutical raw material manufacturing process, a pharmaceutical manufacturing process, a health functional food material manufacturing process, a health functional food manufacturing process, a semiconductor process, Method of controlling water content in carbon dioxide purification process that is applied to one or more processes selected from the group consisting of electronic component manufacturing process and microelectromechanical system process The water content control device in the carbon dioxide purification process includes a first water removal device and a second water removal device.
The primary moisture removal device
a) a compressor for compressing moisture containing carbon dioxide source gas to raise the dew point;
b) a cooler for condensing moisture by cooling the carbon dioxide source gas containing the compressed water in the compressor;
c) a phase separator for flash-expanding the compressed and cooled carbon dioxide source gas into condensed moisture and the condensed moisture removed carbon dioxide feed gas;
d) a rear pressure regulating valve installed in the gas outlet of the phase separator to discharge gas of excess pressure to the rear while maintaining a constant pressure inside the phase separator; And
e) a temperature control device for controlling the temperature inside the phase separator,
The secondary water removal device is installed at the rear of the primary water removal device, it is characterized in that it comprises two or more connected, the gas adsorption dryer having an internal flow of the upper flow from the bottom to the top Content control system in carbon dioxide purification process The method of claim 11, wherein the two adsorption-type dryers connected in parallel, when the residual moisture adsorption process is carried out in any one (or more) of the adsorption-type dryer, the adsorbent in any other (or more) The water content control device in the carbon dioxide refining process, characterized in that the recharging, the adsorption-type drying dryer capable of continuous operation without interruption of operation as water is removed in an alternate operation method.

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