KR20200001407A - Method of Improving the Work Environment in the Alcoholic Beverage Manufacturing Process - Google Patents

Abstract

The present invention relates to a method for improving a work environment in an alcoholic beverage manufacturing process. The alcoholic beverage manufacturing process comprises: a first step of spraying an alanine metal salt solution obtained by converting an ammonium ion (-NH_3^+) of alanine into an active amino group (-NH_2) as a CO_2 absorbent in a scrubber, for the alanine metal salt solution to be in contact with exhaust gas containing high concentration CO_2 of 20,000 ppm or more in an alcoholic beverage manufacturing process, to convert the exhaust gas into exhaust gas containing low concentration CO_2 of 5,000 ppm or less; and a second step of regenerating the CO_2 absorbent by heating the CO_2 absorbent which has absorbed CO_2 through gas-liquid touch in the first step and then, reusing the CO_2 absorbent in the first step.

Description

{Method of Improving the Work Environment in the Alcoholic Beverage Manufacturing Process}

The present invention relates to a method for improving the working environment in a liquor manufacturing process.

Humans have already used natural fermentation using microorganisms in real life since they did not know the meaning of fermentation. The fermentation industry using microorganisms has long been used in the liquor and fermented foods. In recent years, the development of the fermentation industry is expanding in various fields to obtain medical and various high value-added products. Table 1 is an industrial field using microorganisms.

Field product Alcohol production and liquor Wine, Beer, Shochu, Liquor fermented food Soy sauce, miso, kimchi, baker's yeast, cheese, yogurt medicine penicillin, streptomycin, etc. Amino Acid Fermentation Industry Various amino acids such as lycine Enzyme industry amylase, protease, etc. Bioactive substances Vitamins, hormones Cell manufacturing Yeast cell production (single cell protein, SCP) Other fields Environmental purification by microorganisms, production of alternative energy (alcohol, methane, hydrogen), etc.

When using microorganisms as an industrial production means, there are advantages and disadvantages to chemical processes. The advantages of the microbial production process are related to the advantages of the enzyme in it. That is, various substrates are available and specific to the reaction. Microorganisms are also advantageous for use as they proliferate faster than animal and plant cells. Unlike the chemical process, the reaction proceeds at room temperature and pressure, which is advantageous in terms of efficiency. In addition, various by-products can be reused for other purposes, and the heat released during microbial culture can be used, and several steps of chemical reactions can be achieved by the same operation as a single reaction.

Meanwhile, the global average CO ₂ concentration is 405 ppm, and the working environment in the mainstream process, which is an industrial facility that emits high concentrations of CO ₂ , has been shown to exceed _20,000 ppm in indoor CO ₂ concentrations. This provides a very harsh operating environment for the workforce. Although the legal standard is set at 5,000 ppm or less, there is no technical application for environmental improvement.

In order to solve this problem, the liquor factory has no choice but to use the ventilation method that introduces outside air as a measure to reduce the concentration of carbon dioxide in the workplace. Since the temperature control of the indoor air amount including the external air to be introduced is to be added, there is a problem that a significant energy loss for operating the heating and cooling equipment.

In order to solve the inherent problems, the most advanced technology to be achieved is the development of an absorbent capable of efficiently capturing carbon dioxide. The use of superior absorbents can directly contribute to minimizing the cost of carbon dioxide separation and recovery in the mainstream process, as it has the advantage of saving energy and extending the life of the plant.

However, when the existing amine-based absorbent, ammonia absorbent or amine-impregnated adsorbent is used, the human body and food are adversely affected by volatilization of the absorbent.

On the other hand, there may be a way to reduce the amount of carbon dioxide emissions, but considering the limitations of technology and the absence of global energy sources, carbon capture and storage that ultimately capture and process carbon dioxide (CCS: Carbon Capture & Storage) technology needs to be applied. About 70% of the cost of carbon dioxide capture and storage is spent on carbon dioxide capture, and the cost of renewable energy of absorbents for the reuse of carbon dioxide absorbents is the largest part of the carbon dioxide capture process. Currently, representative carbon dioxide capture absorbents have the disadvantage that MEA (MomoEthanolAmine) has a high reaction heat, heat generation, corrosion problems, and a lot of energy consumption and volatilization loss when regenerating the absorbent.

Accordingly, the present invention is to develop a non-volatile, non-toxic, biodegradable high efficiency absorbent suitable for indoor and food and beverage processing of a multi-use facility.

A first aspect of the present invention is in the scrubber, an ammonium ion of an alanine to a CO ₂ absorber (-NH ₃ ⁺⁾ by spraying an aqueous metal salt solution converted to alanine active amino group (-NH _2), a high concentration of more than 20,000ppm mainstream manufacturing process CO ₂ containing exhaust gas by gas-liquid contact with the first step of converting a low-concentration CO ₂ containing exhaust gas of less than 5,000 ppm; And

It provides a liquor manufacturing process comprising a second step of regenerating the CO ₂ absorbent by heating the CO ₂ absorbent absorbed CO ₂ through the gas-liquid contact in the first step and reused in the first step.

The second aspect of the present invention provides a high concentration of more than 5,000 ppm during the fermentation process by spraying an alanine metal salt solution in which a ammonium ion (-NH ₃ ⁺ ) of alanine is converted into an active amino group (-NH ₂ ) with a CO ₂ absorbent in a scrubber. contacting CO ₂ containing exhaust gas and the gas-liquid first step of switching to the low-concentration CO ₂ containing exhaust gas of 5,000 ppm or less with more than 85% CO ₂ removal; And

By heating the CO ₂ absorbent that has absorbed the CO ₂ through the gas-liquid contact in the first stage provides a fermentation process comprising a fermentation step of then play back the CO ₂ absorber a second step of re-use in the first step.

Hereinafter, the present invention will be described in detail.

Ethanol fermentation or alcohol fermentation is a biological process in which sugars such as glucose, fructose and sucrose are broken down into ethanol and carbon dioxide. Ethanol fermentation is used for brewing, ethanol fuel production and baking.

C ₆ H ₁₂ O ₆ → 2 C ₂ H ₅ OH + 2 CO ₂

Alcohol fermentation is considered an anaerobic treatment because it is made by microorganisms such as yeast in the absence of oxygen. The fermentation process does not require oxygen. If oxygen is present, some yeast species will oxidize pyruvate completely to carbon dioxide and water. This process is called cellular respiration. However, these yeast species will form ethanol only in an oxygen-free environment (not cell respiration).

However, many yeasts, such as the commonly used brewer's and split yeast groups, prefer to ferment through breathing. These yeasts produce ethanol even in the presence of oxygen, given the right kind of nutrients.

For example, fermented alcohol is made by fermenting starch, sugar raw materials and the like using yeast. Alcohol production process is shown in Table 2 below.

step Contents Crushing Process of grinding raw materials such as rice and barley Capital increase Process of mixing the pulverized raw material with water and then adding steam and raising the temperature to make it look like grass to facilitate enzyme penetration Saccharification Process of producing sugar by adding glycosylation enzyme to the raw material which has been increased Fermentation Yeast is injected into the glucose produced during the saccharification process to produce alcohol. This process produces about 10% alcohol and carbon dioxide Distillation Concentrates the alcohol produced during fermentation into alcohol of high purity. Impurities are completely removed through five distillation columns black Distillation of alcohol (usually 96%) to a constant frequency (95%) that Jangsu  Go After analyzing the tested spirits, if they meet the quality criteria, they move to the storage tank. Out of storage tanks in the form of tank lorry, drums, cans, etc.

Fermenters are also called bioreactors, and biocatalysts used in bioreactors include enzymes, microorganisms, animal cells, and plant cells, which are suspended or immobilized. do.

Fermentation or cell culture methods include batch culture, continuous culture, fed-batch culture, and the types of fermenters include agitated tank fermenters and bubble column fermenters. lift fermentors and fluidized fermenters. 1 and 2 illustrate an aeration stirring fermentation tank and a bubble column fermentation tank, respectively.

In case of using existing amine absorbent, ammonia absorbent or amine impregnated absorbent, volatilization of absorbent adversely affects the human body and food. Accordingly, there is a need for the development of nonvolatile, nontoxic, biodegradable, high efficiency CO ₂ absorbents suitable for indoor and food and beverage processes in manufacturing facilities.

Monoethanolamine (MEA) of Formula 1, which is a representative CO ₂ absorbent, has the disadvantage of high heat of reaction, heat generation, corrosion and regeneration of the absorbent.

Material corrosion by MEA absorbents starts at about 100 ° C and is about 0.2 to 1 mm / yr for carbon and stainless steels at about 120 ° C. Preservatives are added to prevent corrosion, but loss due to volatilization is inevitable.

On the other hand, the amino acid absorbent has the advantages as shown in the table below compared to the amine absorbent.

No vapor pressure Less sensitive to O ₂  Naturally present Non-volatile
-Inflammable
-Not explosive
-Odorless
No inhalation risk  No degradation -Biodegradable
-Nontoxic
-Environmentally friendly

An amino acid refers to a molecule having both an amine group (-NH ₂ ) and a carboxy (-COOH) group, and generally refers to an alpha-amino acid (HOOC-CH (R) -NH ₂ ) in which both functional groups are attached to one carbon. It is called. Amino acids cannot directly react with carbon dioxide because they are quantized by providing a basic amino group with hydrogen ions contained in an acidic carboxyl group in an aqueous solution.

When the alkali metal is added to the aqueous solution containing amino acid, the alkali metal is substituted with a carboxyl group in which the protons are lost, and the OH ⁻ of the alkali metal and H ⁺ of the ammonium ion are bonded to each other to form an amino group functional group involved in carbon dioxide absorption.

The present invention improves productivity and energy savings through the development of eco-friendly and energy-efficient reduction technology by applying amino acid salt absorbent to overcome the disadvantages of high amine heat absorber which has high energy consumption, high heat generation, deterioration of corrosion and regeneration of absorbent. To develop the technology, amino acid absorbents suitable for the mainstream process were selected through gas-liquid absorption phase equilibrium experiments on various kinds of amino acids.

L-alanine (C ₃ H ₇ NO ₂ ) is an amino acid used in the synthesis of proteins and is not an essential amino acid to be consumed in food because it can be synthesized in the human body, and is present in almost all protein components. When dissolved in water as white powder, it is transparent, has no peculiar protein odor and has low carbon dioxide absorption capacity but high absorption rate, low density and viscosity, and has excellent gas-liquid contact efficiency.

Screening of amino acid salt absorbents using gas-liquid phase equilibrium (VLE) test results showed that L-lysine showed the best carbon dioxide absorption performance, and that L-proline, L-alanine and sarcosine were relatively good. As a result of evaluating the absorption rate using the VLE device for L-lysine, L-proline and L-alanine, which showed excellent absorption performance among the amino acid absorbents, the absorption rate of L-alanine and L-proline was relatively fast. Appeared (FIG. 3).

In the fermentation industrial process in which high concentrations of CO ₂ are emitted, the CO ₂ absorption capacity as well as the CO ₂ absorption capacity are important when removing CO ₂ from the CO ₂ containing gas through gas-liquid contact with the CO ₂ absorption liquid.

L-alanine absorbents have a slightly lower absorption capacity than L-lysine absorbents, but the absorption speed is fast, there is no smell, and there is no problem of foaming due to low density and viscosity. According to the experimental results of carbon dioxide absorption of L-lysine in the scrubber, problems such as backflow and protein odor caused by foaming occurred, and L-alanine had lower absorption capacity but faster absorption rate and foam than L-lysine. It does not occur and appeared to have no peculiar protein odor.

Accordingly, the present invention selects L-alanine as an eco-friendly absorbent for application to the mainstream and food manufacturing process that discharges high concentration CO ₂ containing exhaust gas of 20,000ppm or more, and processes the high concentration CO ₂ containing exhaust gas through a scrubber on a large scale. Is characteristic.

Using the L-lysine absorbent caused excessive foaming during scrubber operation, causing the absorbent to flow back onto the scrubber. This foaming acts as a factor of impairing the gas-liquid contact inside the scrubber to lower the absorption performance.

In addition, the present invention confirmed the applicability in the high concentration CO ₂ reduction process in the mainstream process through the results derived as follows from the CO ₂ removal efficiency of the scrubber using L-alanine:

(1) As a result of experiment of deriving the liquid gas volume and tower speed, which are design conditions, using the 5LPM (Lab-scale) CO ₂ absorption reactor for the design and manufacture of the scrubber, the liquid gas ratio of 85% or more of CO ₂ removal rate for the mainstream process 18 L / m ³ , tower speed was estimated to be 0.14 m / s.

(2) As a result of experiment with 5 m ³ / min class CO ₂ absorption reactor based on design factor, CO ₂ removal rate was 98.47%, 96.46 when the air volume increased by 1, 2, 3, 4, 5 m ³ / min. %, 92.95%, 89.71%, 85.49%. The scrubber was found to have high absorption reproducibility of L-alanine.

(3) According to the present invention, it is possible to save 5.4% of energy, and the energy saving amount is 11.5 TOE / year, and the greenhouse gas reduction amount is 6.5 TC / year.

L-alanine's amino acid salt absorbent has low volatility compared to amine absorbent, so there is little loss, little side reaction and corrosion characteristics, and low renewable energy. The biggest advantage of the carbon dioxide capture process using the amino acid salt of L-alanine is that it can be easily desorbed by heating. The amino acid salt of L-alanine from which carbon dioxide has been released restores its ability to capture carbon dioxide, thereby allowing the absorption / regeneration to proceed repeatedly. L-alanine amino acid salt absorbent can be applied to the actual process because the economical efficiency by the regeneration system and the regeneration cost of the absorbent can be secured

Therefore, the liquor manufacturing process according to the present invention

In the scrubber, by spraying an aqueous solution of alanine metal salt in which ammonium ion (-NH ₃ ⁺ ) of alanine is converted to an active amino group (-NH ₂ ) with a CO ₂ absorbent, a high concentration of CO ₂ -containing exhaust gas and gaseous liquid of 20,000 ppm or more during the mainstream manufacturing process Contacting and converting to a low concentration CO ₂ containing exhaust gas of not more than 5,000 ppm; And

And a second step of regenerating the CO ₂ absorbent by heating the CO ₂ absorbent absorbing CO ₂ through gas-liquid contact in the first step and reusing the CO ₂ absorbent.

At this time, the high concentration CO ₂ containing exhaust gas of at least 20,000ppm during the liquor manufacturing process may be derived from a fermentation tank containing a microorganism.

In addition, the fermentation process according to the present invention

In the scrubber, a CO ₂ absorber alanine ammonium ion (-NH ₃ ⁺⁾ is an active amino group (-NH ₂₎ by spraying an aqueous metal salt solution converted to alanine, the fermentation process of the high concentration of 5,000ppm CO ₂ containing exhaust gas and the liquid in excess of the Contacting to convert to a low concentration CO ₂ containing exhaust gas of 5,000 ppm or less at a CO ₂ removal rate of at least 85%; And

And a second step of regenerating the CO ₂ absorbent by heating the CO ₂ absorbent absorbing CO ₂ through gas-liquid contact in the first step and reusing the CO ₂ absorbent.

At this time, the high concentration CO ₂ containing exhaust gas of more than 5,000ppm during the fermentation process may be derived from the fermentation tank containing microorganisms.

In the first step, the CO ₂ absorbent may include an alkali metal hydroxide (MOH) capable of activating -NH ₃ ⁺ of alanine to -NH ₂ in an aqueous solution.

Regardless of the type of alkali metal, -NH ₃ ⁺ can be activated as -NH ₂ from an alkali cation feed. Non-limiting examples of the alkali metal hydroxide (MOH) is NaOH, LiOH, KOH and the like.

In the first step, the high concentration CO ₂ containing exhaust gas may be collected by a deodorizing fan.

The scrubber may be composed of a CO ₂ containing gas injection unit, a CO ₂ absorption reactor equipped with a gas-liquid contact module, a CO ₂ absorbent supply tank, and a gas analysis measurement unit (FIG. 5).

In the scrubber according to one embodiment of the present invention, the CO ₂ containing gas is transferred to the gas inlet of the scrubber main body (CO ₂ absorption reactor) and passes through the filling layers of each stage, and the CO ₂ absorbing liquid and gas-liquid sprayed by the SPRAY pipe on the top of the filling layer. It may be a facility for reducing CO ₂ by contact.

Method for removing carbon dioxide from a high concentration of CO ₂ containing gas through the gas-liquid contact with the CO ₂ absorbing solution in the scrubber according to the invention, by using the heat from the CO ₂ absorbing liquid that has absorbed the CO ₂ through chemisorption stripping the CO ₂ The CO ₂ absorbent liquid can be regenerated and the regenerated CO ₂ absorbent liquid can be reused.

For example, but how in the scrubber according to the invention through the gas-liquid contact with CO ₂ absorbing liquid to remove the CO ₂ from the high concentration of CO ₂ containing gas is supplied to the CO ₂ absorbing solution and the CO ₂ containing exhaust gas in the absorber, respectively, the gas-liquid contact in the module the absorption liquid absorbs the CO ₂ in the CO ₂ containing exhaust gas and discharging the CO ₂ absorbing solution and the CO-containing exhaust gas is removed by absorbing the ₂ and CO _2, respectively; Vaporize the CO ₂ by heating the CO ₂ absorbing solution discharged from the absorption tower contained in tower and reproduction, respectively, and discharging the CO ₂ absorbing solution in the gas phase can be regenerated by absorbing liquid.

In the second step for reproducing the CO ₂ absorbent by heating the CO ₂ absorbent that absorbs CO _2, playback state of the CO ₂ absorbent may be determined by measuring the pH of the CO ₂ absorbent. As the regeneration is increased, the pH of the CO ₂ absorbent increases and the regeneration of the CO ₂ absorbent can be confirmed by measuring the pH of the CO ₂ absorbent from the known pH value of the CO ₂ absorbent according to the regeneration degree.

The heating temperature for regeneration of the CO ₂ absorbent is preferably adjusted to 100 to 250 ° C. Above 100 ° C., the carbon dioxide desorption efficiency is improved by water vapor pressure, and above 250 ° C., alanine may be decomposed.

On the other hand, it is preferable to control the concentration of alanine within 0.1 ~ 5M to form alanine metal salt in the aqueous solution so that the scrubber does not bubble when spraying the CO ₂ absorbent nozzle.

According to the present invention, in order to adjust the CO ₂ removal rate to 85% or more in the high concentration CO ₂ -containing exhaust gas through gas-liquid contact with the CO ₂ absorbent in the scrubber, the liquid gas ratio is 1 to 20 L / m ³ and the axle speed is 0.1 Can be adjusted from ~ 1 m / s.

According to the present invention, in the scrubber, an aqueous solution of alanine metal salt in which ammonium ion (-NH ₃ ⁺ ) of alanine is converted into an active amino group (-NH ₂ ) as a CO ₂ absorbent is sprayed, and a high concentration of CO ₂ -containing exhaust gas and gaseous gas is _20,000 ppm or more. when in contact, it is possible to reduce CO ₂ in the low-concentration CO ₂ containing exhaust gas of 5,000 ppm or less. In addition, the operation of the scrubber in the liquor manufacturing process and the fermentation process solves the problem of significant energy loss for operating the heating and cooling equipment when controlling the temperature of the indoor air, including the external air, which is additionally introduced to reduce the indoor carbon dioxide concentration. Can be.

1 and 2 illustrate aeration stirring fermentation tank and bubble column fermentation tank, respectively.
Figure 3 is a graph comparing the carbon dioxide absorption rate of L-lysine, L-alanine, L-proline absorbent.
Figure 4 is a graph showing the measurement results of carbon dioxide absorption capacity of L-lysine, L-alanine, L-proline absorbent.
FIG. 5 is a conceptual diagram illustrating a wet scrubber used in Example 3. FIG.
Figure 6 is a graph showing the CO ₂ removal rate according to the liquid gas amount (Liquid to gas ratio, L / m ³ ) in Example 3.
Figure 7 is a graph showing the CO ₂ removal rate according to the tower speed in Example 3 (CO ₂ Removal Efficiency according to Superficial velocity (m / s)).
8 is a graph showing a correlation between the rpm of the inlet fan and the flow rate CMM in Example 3. FIG.
FIG. 9 is a graph showing CO ₂ concentration according to flow rates in Example 3. FIG.
10 is a graph showing the CO ₂ removal rate according to the flow rate in Example 3.
FIG. 11 is a conceptual diagram illustrating a system for testing a continuous CO 2 capture and regeneration process in Example 3 (Schematic diagram of continuous process for CO 2 capture and regeneration).
12 is a graph showing the results of regeneration experiments of L-lysine and L-alanine.
13 is a graph comparing regeneration efficiency of L-lysine and L-alanine.
14 is a graph comparing continuous regeneration efficiency of L-lysine and L-alanine.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, these examples are for illustrative purposes only and the scope of the present invention is not limited to these examples.

Example  1: Screening amino acid absorbents suitable for mainstream processes

The amino acid absorbents suitable for the mainstream process were selected through gas-liquid absorption equilibrium experiments using a gas-liquid phase equilibrium (VLE) test apparatus for various kinds of amino acids, as shown in Table 4 below.

In order to activate the amino group (-NH ₂ ) of the amino acid to prepare a 0.1 M aqueous solution of amino acid salt concentration of KOH in the same molar ratio to evaluate the carbon dioxide absorption performance.

From the screening results of the amino acid salt absorbent, L-lysine showed the best carbon dioxide absorption performance, and L-proline, L-alanine, sarcosine also showed a relatively good performance.

As a result of evaluating the absorption rate using the VLE device for L-lysine, L-proline, and L-alanine showing excellent absorption among the amino acid absorbents, the absorption rate of L-alanine and L-proline was relatively fast (FIG. 3). .

Meanwhile, in order to evaluate the CO ₂ absorption capacity of the amino acid absorbent, an absorption reaction system (CSTR) was constructed to evaluate the absorption performance.

Figure 4 shows the measurement results of carbon dioxide absorption capacity of L-lysine, L-alanine, L-proline absorbent.

As shown in the VLE and CSTR screening results, L-lysine absorbent showed the highest CO2 absorption capacity with 0.67 absorption capacity, and L-alanine and L-proline absorbents showed carbon dioxide absorption capacity of 0.61 and 0.52, respectively.

Example  2: L- in indoor and food process alanine  Excellence and suitability of absorbent

As shown in Example 1, the L-lysine absorbent showed excellent carbon dioxide absorption performance, but the test was stopped due to the unique protein smell of L-lysine during the field test.

In addition, when the scrubber is operated using the L-lysine absorbent, excessive foaming occurs, causing the absorbent to flow back onto the scrubber. This foaming acts as a factor of impairing the gas-liquid contact inside the scrubber to lower the absorption performance.

On the other hand, L-alanine absorbents have somewhat lower absorption capacity than L-lysine absorbents, but the absorption rate is fast, no smell, and there is no problem of foaming due to low density and viscosity.

Example  3: L- alanine Amino acid salt  Carbon dioxide absorption performance evaluation of absorbent

3-1. Lab-scale CO ₂  Absorption reactor

Reagent (A), in which 45 g of L-alanine (Daejungchem, purity> 99%) was dissolved in 500 ml of water, and reagent (B), in which 30 g of KOH (Daejungchem, purity> 85%) was dissolved in 425 ml of water, were mixed 1: 1. and the mixture was stirred slowly rolling the reagents (B) to the reagent (a) by preparing a CO ₂ absorber 1 kg, to prepare a CO ₂ absorbent.

5 L / min (Lab-scale) CO ₂ absorption reactor is a wet scrubber as shown in Figure 5 is composed of a gas injection unit, absorption reactor, absorbent supply tank, gas analysis measurement unit. The absorption reactor was made of acrylic of 80 cm in length and 9 cm in diameter, and four nozzles were connected inside the reactor.

A standard CO ₂ gas (Deokyang Co.) is a high concentration of a standard nitrogen as balance with 2% CO ₂ in consideration of the process liquor in a high concentration of CO ₂ condition in order to derive the absorption performance of the absorbent at the high concentration used in the absorbent material The gas was used as an absorbent material and was constantly fed through a flow meter before entering the reactor.

In addition, absorption experiments were performed at room temperature (25 ℃) and atmospheric pressure (1 atm), and CO ₂ gas concentration was set at the reactor outlet by AQ200 (KIMO Co.), and the inlet and outlet concentrations were real-time by-pass. Measured.

[ CO2 absorption performance evaluation ]

For the design and fabrication of the scrubber, the experiment of deriving the liquid gas volume and the tower speed were carried out using a 5 L / min (Lab-scale) CO ₂ absorption reactor. Figure 6 shows the CO ₂ removal rate according to the amount of liquid gas. In order to calculate the amount of liquid gas, the experiment was carried out under the conditions of gas flow rate 3 L / min, absorbent 0.5 M, CO ₂ concentration (based on the mainstream process). When the concentration of the absorbent is high, bubbles are generated. Experiment with liquid gas ratio 2, 5 ~ 25 L / m ³ (5 L / m ³ intervals) showed that the highest removal rate was achieved by removing 86.4% of CO ₂ when the liquid gas ratio was 20 L / m ³ . It was found to decrease from 8 m / m ³ to 85.5%. CO ₂ removal rate of 85% or more liquid gas ratio for application to the mainstream process was estimated to 18 L / m ^3.

Figure 7 shows the CO ₂ removal rate according to the tower speed. The experiment was carried out under the conditions of liquid gas ratio of 18L / m ³ , absorbent 0.5 M, CO ₂ concentration 2% to determine the tower speed. When the superficial velocity 0.1 m / s, CO ₂ is shown to remove 86.4% showed the highest removal rate CO ₂ removal rate decreases as the superficial velocity increases. CO ₂ removal superficial velocity less than 85% for application to the mainstream process was estimated to be 0.14 m / s.

3-2. 5 m ³ / min grade CO ₂  Absorption reactor

For the design and fabrication of a 5 m ³ / min class CO ₂ absorption reactor, experiments were carried out on the liquid gas volume and the tower speed. Lab-scale experiments were performed under the conditions of gas flow rate 3 L / min, absorbent 0.5 M, and CO ₂ concentration 2% to calculate the amount of liquid gas, and 5 m ³ / min based on design factors derived from lab-scale experiments. The specifications of the grade CO ₂ absorption reactor are shown in Table 5.

Max. Flow rates 1700 rpm Number of Nozzles 4x2 (4 per floor) Volume of Absorbent tank 1,000 L Fan inlet damper ø200 Inlet duct 180 x 220 Scrubber cone ø900x450H Scrubber base ø1000 + (700Wx1,100L) Scrubber body ø900x5,500H

By connecting the scrubber and absorbent tank, the absorbent used to operate the scrubber was transferred to the absorbent tank again, and four nozzles were formed on each of two layers to inject a large amount of absorbent to increase the amount of gas-liquid contact. .

In addition, the flow rate of the inlet fan was made to be adjusted within the range of 0 ~ 1700 rpm. The wind speed was measured at the outlet of the scrubber, and the air volume was calculated by multiplying the outlet cross-sectional area. 8 is a data showing a correlation between the rpm of the inlet fan and the air flow rate.

In order to evaluate the carbon dioxide absorption performance of the scrubber, about 760 L (about 70% of the total tank) of the absorbent was injected into the absorbent tank so that the absorbent was evenly sprayed. A CO ₂ measuring device is installed at the front and rear of the scrubber while maintaining the air flow rate 1 ~ 5 m ³ / min, temperature (15 ℃), atmospheric pressure (1 atm), and CO ₂ (2.4%), which are the environmental conditions of the mainstream process. The removal efficiency experiment of the scrubber was performed.

[ CO2 absorption performance evaluation ]

Increased by one step from 5 m ³ / min-grade CO ₂ for 1 FAN air volume to the absorption reactor, m ³ / min was created based on the design parameters to 5 m ³ / min of CO ₂ removal rate experiments were performed. After FAN operation, the experiment was performed for 30 minutes from 5 minutes after the stabilization time, and CO ₂ was measured using GASTIGER2000 (YANTSTAR Instrument Co.). CO ₂ removal rate experiment results are shown in FIG. The incoming CO ₂ concentration was analyzed at about 24,000 ppm.

When the air volume increased to 1, 2, 3, 4, 5 m ³ / min, the CO ₂ removal rate decreased to 98.47%, 96.46%, 92.95%, 89.71% and 85.49%. 10 is a result of the reproducibility test of the scrubber through five measurements for each air volume, the standard deviation was analyzed to be 0.63 ~ 0.94 as a result of repeatedly performing the CO ₂ removal experiment according to the air volume. It was confirmed that the absorption reproducibility of L-alanine used in the present invention is high. As the air volume increases, the CO ₂ removal rate will decrease with decreasing gas-liquid contact, and it is necessary to increase the concentration of the absorbent used in the experiment and change the formulation method.

[ Energy Improvement Rate Evaluation ]

MI2883 (Metrel Co.) was installed in the unit cooler (air conditioner) to evaluate the energy improvement rate before and after using the scrubber. Since power consumption is the same with time, power consumption was measured through power measurement for 5 minutes. The energy improvement rate was calculated using Equation 1.

[Equation 1]

here,

A: Unit cooler power (kWh) before scrubber starts

B: Unit cooler power (kWh) after scrubber starts

Energy savings (TOE / year) and greenhouse gas reductions (TC / year) were calculated using energy savings (Equation 2) and greenhouse gas reductions (Equation 3), respectively.

[Equation 2]

Ea = (A-B) × t × U × α

here,

A: Power consumption of existing system (W / unit)

B: Power consumption of the developed system (W / unit)

t: Uptime per year (hr / year)

U: Real quantity unit

α: conversion factor

[Equation 3]

E _b = E _a × β

here,

Ea: Energy savings (TOE / year)

β: 0.5642 (TC / TOE)

As a result of evaluating the energy improvement rate before and after using the scrubber using MI2883 (Metrel Co.), the unit cooler (air conditioner) and the outside air fan that discharges CO ₂ to the outside are always operated before operating the scrubber device. After operating the scrubber system, the internal temperature could be kept low without the unit cooler and the external fan operating and CO ₂ could be removed excessively. The amount of power according to the operation of this scrubber device is shown in Table 6 (Wattage according to Scrubber ON / OFF).

When operating the scrubber device, energy of 5.4% can be improved, and the energy improvement rate is increased by shortening the operating time of the scrubber device as well as improving the CO ₂ removal rate by increasing the concentration of the absorbent or changing the mixing method. It seems to be possible. In addition, the energy saving amount / greenhouse gas reduction amount was estimated by 11.5 TOE / year, and the greenhouse gas reduction amount was 6.5 TC / year. It is thought to contribute.

Example  4: Amino acid salt  Data acquisition and evaluation of continuous regeneration efficiency for continuous regeneration system of absorbent

Basic experiments were conducted to establish the continuous regeneration process of the amino acid salt absorbent and to confirm the regeneration efficiency. Data acquisition and continuous regeneration efficiency for the continuous regeneration system of the amino acid salt absorbent were evaluated.

The experimental apparatus shown in FIG. 11 was separately configured for continuous carbon dioxide absorption / regeneration experiments. A micro bubble device was used for the continuous absorption (capture) reaction, and a device for regeneration of the absorbent absorbed with carbon dioxide was also constructed and experimented continuously. For the regeneration reaction, condenser was installed to prevent the water level lowered by water vapor generated by heating, and condensed water vapor was introduced into the reactor. To check the reaction temperature, install a temperature sensor (T / M K-type thermocouple, DATA logger; Graphtec GL240) to check the desorption efficiency according to the reaction temperature and use MFC (Mass Flow Controller, Line tech; N₂10 SLPM / CO₂100 SCCM) Inlet concentration and flow rate were adjusted.

In order to confirm continuous absorption / regeneration efficiency, one absorbent was prepared and repeated absorption and regeneration experiments were conducted. The control absorbent used potassium L-lysinate, which is an easy-to-regenerate amino acid salt series, and also had excellent CO2 capture ability, and was prepared by mixing L-lysine monohydrochloride and potassium hydroxide in 0.5: 1.0 moles. Potassium L-alaninate was also prepared using L-alanine in the same manner, and the experiment was conducted. Reagents used in the preparation were L-lysine (98.5-101.0%), L-alanine (> 99%) and KOH (> 85%).

Carbon dioxide used in the absorption reaction was simulated gas diluted in N₂ gas, and MFC was used to maintain a constant concentration. The regeneration reaction temperature was maintained at 120 ° C. and the reaction was continued. The experiment was performed by controlling the temperature of the condenser at 2 ° C. for the return of evaporated vapor. The condensed steam flowed back into the reactor through the pump to maintain the water level and concentration of the absorbent. The exhaust gas was analyzed for CO2 concentration using CO₂analyzer (Senseair, CO₂engine® K30 3%).

The total flow rate of the injected gas was fixed at 4 L / min and the carbon dioxide absorption reaction was carried out through bubbling at a carbon dioxide concentration of 7,300 ppm, and the absorption reaction was terminated after the breakthrough. It absorbed a total of 14.9 L of carbon dioxide and converted to moles of 1.336 mol-co₂ / mol-lysine. The regeneration efficiency was confirmed through the result of the detachment reaction, which was calculated in the same manner as in Equation 4.

[Equation 4]

here,

Vd: Carbon dioxide desorption volume [L]

Va: Carbon dioxide absorption Volume [L]

R: Regeneration efficiency [%]

In order to evaluate the carbon dioxide desorption performance of the amino acid saline solution, a desorption experiment was conducted using L-alanine and L-lysine. Each absorbent was neutralized with 1 mol of potassium hydroxide (KOH) for smooth reaction with carbon dioxide, and 0.5 mol of each amino acid. Both absorbents captured carbon dioxide until breakthrough, and the desorption experiment was carried out while maintaining the solution temperature at 120 ℃. The vapor evaporated during the reaction is liquefied through the condenser and then introduced into the reaction vessel to maintain a constant level to minimize the problems caused by evaporation.

12 shows the regeneration test results of the two materials. As can be seen from the graph, the reaction rate of L-alanine was faster than that of L-lysine, but L-lysine was higher in the amount of detachment. L-alanine absorbed 8.49 L of carbon dioxide, whereas L-lysine absorbed 14.9 L of carbon dioxide. However, in the desorption experiment conducted for about 8 hours, the amount of L-alanine was 4.01 L, and L-lysine was 9.26 L. As shown in FIG. 13, L-alanine was 47.26% and L-lysine was 62.11%. Regeneration efficiency of L-lysine was higher. In both materials, the stage of desorbing carbon dioxide at a high concentration is performed only at the beginning of the reaction, and only about 30-40% of the carbon dioxide is desorbed. Most of the carbon dioxide above 60% is emitted at low concentrations below 800 ppm, and very long time is required for the complete regeneration of the absorbent.

[ Performance Evaluation of Potassium L- lysinate Continuous Regeneration ]

Continuous regeneration performance was evaluated through continuous absorption / regeneration repeated experiments of Potassium L-lysinate sorbent, and FIG. 14 shows the results of continuous regeneration experiments. The continuous regeneration experiment was performed by controlling the time required for desorption for each experiment to 8 hours as a characteristic of the desorption reaction which takes a long time. As the number of regeneration was increased, the regeneration efficiency gradually decreased.

If the regeneration reaction is continuously performed for a long time, it is thought that the high efficiency of regeneration efficiency can be secured regardless of the number of regeneration times. The reaction time is thought to be longer as the number of regeneration increases.

During the carbon dioxide absorption / regeneration reaction, the pH concentration of the solution showed a big change. Initially, the pH of potassium L-lysinate was 11.56, but after the completion of CO₂ absorption, the pH was lowered to 9.45, and the pH of the regenerated solution was 11.52. Through this result, it is possible to intuitively check the detachment state of the absorbent by the pH concentration when applying the industrial process of the absorbent, so that it is possible to confirm the regeneration state of the absorbent without a separate process for confirming the regeneration state of the absorbent.

Claims (9)

In the scrubber, by spraying an aqueous solution of alanine metal salt in which ammonium ion (-NH ₃ ⁺ ) of alanine is converted to an active amino group (-NH ₂ ) with a CO ₂ absorbent, a high concentration of CO ₂ -containing exhaust gas and gaseous liquid of 20,000 ppm or more during the mainstream manufacturing process Contacting and converting to a low concentration CO ₂ containing exhaust gas of not more than 5,000 ppm; And
And a second step of regenerating the CO ₂ absorbent by heating the CO ₂ absorbent absorbing CO ₂ through gas-liquid contact in the first step and reusing the CO ₂ absorbent in the first step. 2. The liquor manufacturing process according to claim 1, wherein at least 20,000 ppm of a high concentration of CO ₂ -containing exhaust gas is derived from a fermentation tank containing microorganisms. The method of claim 1, wherein in the second step, the playback state of the CO ₂ absorbing agent is characterized by the mainstream manufacturing process to determine through pH measurement of the CO ₂ absorbent. The method of claim 1, wherein in a first step 1, the CO ₂ absorbent mainstream manufacturing process is characterized by containing an alkali metal hydroxide (MOH) that can activate the -NH ₃ ⁺ of alanine with -NH ₂ in an aqueous solution. The process of claim 1, wherein in the first step, the concentration of alanine capable of forming alanine metal salt in the aqueous solution is adjusted to 0.1 ~ 5 M so that the scrubber does not bubble when spraying the CO ₂ absorbent in the nozzle . In the scrubber, a CO ₂ absorber alanine ammonium ion (-NH ₃ ⁺⁾ is an active amino group (-NH ₂₎ by spraying an aqueous metal salt solution converted to alanine, the fermentation process of the high concentration of 5,000ppm CO ₂ containing exhaust gas and the liquid in excess of the Contacting to convert to a low concentration CO ₂ containing exhaust gas of 5,000 ppm or less at a CO ₂ removal rate of at least 85%; And
And a second step of regenerating the CO ₂ absorbent by heating the CO ₂ absorbent absorbing CO ₂ through gas-liquid contact in the first step and reusing the CO ₂ absorbent. 7. The fermentation process according to claim 6, wherein more than 5,000 ppm of high concentration CO ₂ containing exhaust gas is derived from a fermentation tank containing microorganisms. The method of claim 6, wherein in the second step, the reproduction state of the CO ₂ absorbing agent is characterized by a fermentation process to make via pH measurements of the CO ₂ absorbent. The method of claim 6, wherein in a first step 1, CO ₂ absorbent of a fermentation process is characterized by further comprising an alkali metal hydroxide (MOH) that can activate the -NH ₃ ⁺ of alanine with -NH ₂ in an aqueous solution.

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