KR101571322B1 - Method for manufacturing of bio- alcohol by biological process using hollow fiber membrane from waste and synthetic gases - Google Patents

Abstract

Discloses a method for producing a bio-alcohol through a biological conversion process using a carbon dioxide, carbon monoxide, hydrogen, etc. contained in exhaust gas and syngas and using a hollow fiber membrane. More specifically, an organic acid such as acetic acid or butyric acid is produced by supplying gaseous substances such as carbon dioxide, carbon monoxide and hydrogen into the hollow fiber membrane and forming a biofilm using the same as a substrate on the outside of the hollow fiber membrane. Discloses a process for producing a bioalcohol through a hydrogenation single process such as a process in which esterification and hydrogenolysis are linked through a catalytic reaction or a hydrocracking reaction, and a method for directly producing a bioalcohol by a biofilm. According to an embodiment of the present invention, it is possible to efficiently and economically produce bio-alcohols from global warming substances or air pollutants, and it is possible to produce bio-alcohols with high yield and high productivity as compared with conventional pressure bioreactors, In addition to pollution resolution, clean fuel can be economically obtained.

Flue gas, syngas, hollow fiber membrane, ethanol, acetic acid, hydrogen, esterification, hydrocracking reaction

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing bioalcohol from a flue gas and a syngas by a bioreaction process using a hollow fiber membrane,

The present invention relates to a method for producing a bio-alcohol from an exhaust gas and a syngas by a bioreaction process using a hollow fiber membrane.

Greenhouse gases include carbon dioxide (CO _2), nitrous oxide (N ₂ O), freon (CFCs), sulfur fluoride (SF ₆₎ and tropospheric ozone (O _3). Of these, carbon dioxide generates the most carbon dioxide and contributes about 50% to global warming. Also preferred hide substance (carbon dioxide, methane, nitrous oxide in accordance with the Kyoto Protocol, which contains the implementation plan for the prevention of global warming (N ₂ O), fluorocarbon (PFC), hydrofluorocarbon (HFC) and a fluorinated sulfur (SF ₆ )), It is necessary to take practical measures to reduce carbon dioxide, and it is necessary to collect, process, and use low-cost, environment-friendly carbon dioxide. The treatment process of the flue gas containing carbon dioxide is classified into separation and immobilization, and chemical immobilization (chemical fixation), electrochemical method and biological fixation method are examples of immobilization. Among the methods of immobilizing carbon dioxide, the technology of reusing carbon dioxide using chemical catalysis enables the production of various chemical substances according to the development of various high efficiency catalysts, and a catalytic reduction method using hydrogen has also been reported. Until recently, in the case of carbon dioxide immobilization by biological methods, most of them have been limited to the method of converting carbon dioxide into biomass using photosynthetic microorganisms. Currently, researches for practical use of a carbon dioxide immobilization process by a biological method are being conducted in major advanced countries , It is very difficult to find the design of reactors capable of immobilizing carbon dioxide emitted from industry and the operating conditions thereof, and there has not been reported an example in which a process for immobilizing carbon dioxide emitted from industrial bodies by biological methods is practically used.

The gasification process of flammable waste such as waste plastics and waste wood is actively being studied as part of waste reduction and energy resources, and gasification is carried out by using carbon, oxygen, air and steam in waste to synthesize carbon monoxide and hydrogen gas, Gas (syngas) and ash residue. The syngas produced by such gasification can be used as fuel for gas turbines and industrial furnaces after purification process for removing hydrogen sulfide and carbon dioxide, which are byproducts, and can be converted to methanol, which is a basic raw material of the chemical industry. As a technology related to this gasification, currently pre-treatment technology, gasification device technology and scale-up technology are being secured in advanced countries to improve gasification efficiency. Refining technology for the use of generated syngas and conversion of syngas to methanol Technology has been developed. On the other hand, in Korea, as a part of the technology development for improving the gasification efficiency, only a part of the technology for the gasification apparatus based on the operation experience of the coal-fired power plant and the raw material treatment technology for improving the gasification efficiency is secured. In addition, the use of syngas is still at a basic stage, and research on the production of useful materials using syngas is extremely limited. When a catalytic reaction, which is a chemical method, is used as a method for producing a useful substance using syngas, it reacts very sensitively to a small amount of impurities. Therefore, a useful substance such as synthetic oil is produced from a syngas containing a large amount of impurities A purification process is absolutely necessary. However, the application of biological methods does not require high-purity reactants as in the catalytic reactions. Therefore, syngas can be used immediately without additional purification process, and reaction conditions are at room temperature and atmospheric pressure. There is a low advantage.

Carbon dioxide, carbon monoxide, and hydrogen are converted into various substances by aerobic or anaerobic microorganisms. In particular, acetic acid producing microorganisms produce acetic acid by using carbon dioxide, carbon monoxide and hydrogen through anaerobic respiration during metabolism. These acetic acid-producing microorganisms can utilize various types of substances as energy and carbon sources, and in particular, have acetogenic metabolism for producing acetic acid by using carbon dioxide and carbon monoxide as a carbon source and hydrogen as an energy source. It is also reported that the anaerobic microorganism can produce ethanol using carbon monoxide, carbon dioxide, and hydrogen as a substrate. In particular, Clostridium ljungdahlii, Eubacterium limosum, Peptostreptococcus productus are representative of these microorganisms.

However, since carbon dioxide, carbon monoxide, and hydrogen, which are the main substrates of the biological conversion reaction, are gaseous substances and the water solubility is extremely low, it is very difficult for the microorganisms to utilize it. Thus, the efficiency of the bioalcohol- It is difficult to apply it to a large-scale process. In order to overcome the water solubility problem of these gaseous materials, the conversion of the gaseous materials to organic acids or bio - alcohols was still low, though the conversion was increased by increasing the pressure in the microbial reactor.

The present invention relates to a method for supplying a gaseous substance into a hollow fiber membrane at a constant pressure and attaching a microorganism capable of converting a gaseous substance into an organic acid or a bioalcohol on the outer wall of the hollow fiber membrane, Thereby maximizing the degree to which the bio-alcohol can be used as a bio-alcohol, thereby providing a method for efficiently and economically producing bio-alcohols such as ethanol and butanol.

The present invention relates to a method for producing a bio-alcohol from an exhaust gas and a syngas, comprising the steps of feeding a flue gas and a syngas to a pore in the hollow fiber membrane at a constant pressure and attaching a microorganism producing an organic acid or a bio- Producing alcohol; In the case of the produced organic acid, it is separated and purified to produce a bioalcohol by esterification or hydrogenation reaction with an alcohol such as ethanol or butanol. In the case of an alcohol directly produced by a microorganism, the product is separated and purified as a final product ; And separating and purifying the produced alcohol through the above two steps to obtain an end product, or using a part of the alcohol as a hydrogenation reaction additive of an organic acid.

According to an embodiment of the present invention, an exhaust gas and syngas containing a low-water-solubility gaseous material are supplied into the hollow fiber membrane and microorganisms that convert these gas phase materials into organic acids or alcohols are immobilized on the outer wall of the hollow fiber membrane , Bio-alcohol can be produced efficiently and economically. In addition, it is anticipated that it will be possible to observe greenhouse gases, reduce waste, and convert energy resources into energy.

Hereinafter, the present invention will be described more specifically.

The present invention relates to a method for producing bio-alcohols through a biological conversion process using a hollow fiber membrane using carbon dioxide, carbon monoxide, hydrogen, etc. contained in exhaust gas and syngas. More specifically, an aerobic or anaerobic biofilm is formed by supplying gaseous substances such as carbon dioxide, carbon monoxide, and hydrogen into the hollow fiber membrane and using the same as a substrate outside the hollow fiber membrane to produce an organic acid such as acetic acid or butyric acid. A process in which esterification and hydrogenolysis are linked through a chemical catalytic reaction or a process for producing a bioalcohol through a hydrogenation process such as a hydrocracking reaction and a process for directly producing a bioalcohol by a biofilm will be.

In the present invention, the bioalcohol includes bioethanol and biobutanol, the organic acid includes acetic acid and butyric acid, and the gaseous materials include carbon dioxide, carbon monoxide and hydrogen. The main component of exhaust gas or syngas is carbon dioxide, and it may contain carbon monoxide and hydrogen generated by gasification of flammable waste.

In the present invention, microorganisms that produce organic acids or alcohols are immobilized on the outer wall of the hollow fiber membrane using carbon dioxide, carbon monoxide, or hydrogen contained in exhaust gas or syngas as a substrate, while supplying exhaust gas or syngas at a constant pressure through the pores in the hollow fiber membrane And immersing the hollow fiber membrane in a microorganism culture liquid to produce an organic acid or an alcohol.

A method for producing a bio-alcohol from an exhaust gas or a syngas according to an embodiment of the present invention includes the steps of: a) supplying a flue gas or syngas into a hollow fiber membrane in which a microorganism producing an organic acid or a bio- A step of immersing in a nutrient-containing culture medium to produce an organic acid or a bio-alcohol through a microorganism conversion reaction; b) supplying an organic acid or an organic acid salt from the culture solution to a liquid-liquid extraction column and extracting organic acid through an extraction solvent; c) extracting, separating and distilling the bio-alcohol directly produced from the biogas or syngas by the microorganism in the step a), thereby producing the bio-alcohol; d) introducing the organic acid mixed with the extraction solvent of step b) into a distillation column to fractionally distill the organic acid and the extraction solvent, and then supplying the separated extraction solvent as the extraction solvent of step b); e) Converting the organic acid of step d) into an ester compound through an esterification reaction process or converting the alcohol into an alcohol through a hydrocracking reaction process to convert the alcohol into an end product; f) obtaining a part of the ester compound of step e) as an end product and the remainder is supplied to a hydrocracking reactor to convert it to an alcohol; g) the alcohol obtained by the hydrocracking reaction of the above f) and a part of the alcohol obtained in the step e) are obtained as the final product and the remaining is used for the esterification and hydrocracking reaction of the step e).

( Clostridium ljungdahlii, Clostridium autoethanogenum, Clostridium carboxidivorans ) and Eubacterium limosum, Peptostreptococcus productus, Oxobacter pfennigii, Acetobacterium woodii, Butyribacterium methylotrophicum, Bacillus thuringiensis, and the like are examples of microorganisms producing organic acids or alcohols using carbon dioxide, carbon monoxide , Methanosarcina acetivorans, Moorella thermoacetica, Moorella thermoautotrophica, and the like.

Microorganisms for producing organic acids or alcohols by using gaseous substances are formed into a biofilm on the outer wall of the hollow fiber membrane and immobilized thereon or suspended in a bioreactor to form microorganisms in the microfluidic system, To produce organic acids and alcohols. The produced alcohol may be produced as a final product through pure separation and purification processes such as a distillation process or may be used as an additive in an alcohol conversion process of an organic acid, which will be described later.

Carbon dioxide and / or carbon monoxide and hydrogen in a volume ratio of about 1: 0.5 to 7, and the operating temperature of the bioreactor can be maintained at 25 to 40 ^° C.

The extraction of the organic acid or the organic acid salt from the culture liquid is carried out by supplying carbon dioxide contained in the exhaust gas or the synthesis gas to the extraction reactor at a pressure of 10 to 50 atm to lower the pH of the culture liquid to a pH of 4 or less to maximize the extraction efficiency by the extraction solvent . To extract the organic acid, a co-solvent of the ketone may be mixed with an extraction solvent to improve extraction efficiency and separation efficiency.

The extracted liquid passed through the liquid-liquid extraction process is introduced into the distillation column to obtain the organic acid at the top of the distillation column and the extraction solvent is recovered at the bottom of the distillation column. The operation temperature of the distillation tower may vary depending on the type of the extraction solvent. In the case of tripentylamine, the operation temperature is preferably 90 to 200 ^° C. In this case, the extraction solvent recovered from the bottom of the distillation tower is liquid- Can be reused as an extraction solvent for.

The organic acid recovered from the top of the distillation column mentioned above is introduced into an esterification reactor together with an alcohol to be converted into an ester compound. The alcohol used in the esterification reaction may be produced by the hydrogenation reaction described later, , And then it may be part of the purified and purified alcohol. Some of the ester compounds produced in the esterification reaction can be converted into diesel or mixed with diesel and used as a final product and the remainder can be supplied to a subsequent hydrocracking reactor and converted to alcohol.

As described above, the organic acid produced by the microorganism, separated and purified may be directly converted to alcohol through the hydrocracking reaction using the alcohol as an additive instead of the esterification reaction.

Hydrogen used in hydrocracking reaction can be hydrogen or hydrogen produced by microbial fermentation, supplied from hydrogen gas or other hydrogen generators.

The hydrocracking reaction is a reaction using a catalyst capable of inducing a hydrocracking reaction in which one or two or more metal oxides are supported on a support. Examples of metal oxides that can be supported on the catalyst include copper oxide, chromium oxide, zinc oxide, nickel Oxides, molybdenum oxides, cobalt oxides, iron oxides, and the like.

The hydrocracking reaction is preferably operated at a temperature of 120 to 350 ^° C and a pressure of 1 to 70 bar.

Hereinafter, the present invention will be described in more detail by way of examples, but the scope of the present invention is not limited thereto.

[Example 1] Production of organic acid using hollow fiber bioreactor

A hollow fiber bioreactor with an effective volume of 195 ml was operated under the condition of pH 7, in which an acrylic reactor having a total volume of 1.3 L was filled with 1,000 strands of polysulfone hollow fibers. In order to maintain the internal temperature of the hollow fiber membrane reactor, the hose was wound around the outside, and the temperature was adjusted to 35 to 38 ° C by circulating hot water in the hose by using a heating circulator. A mixed gas composed of carbon dioxide and hydrogen at a volume ratio of 1: 4 was injected into the hollow fiber membrane and maintained at about 0.2 to 0.3 atmospheric pressure on the pressure gauge and increased to 0.5 atmospheric pressure in the latter half, To the extent of change. Organic acid producing microorganisms were implanted with 20% (v / v) of the effective volume. The micronutrients in the culture medium were as shown in Table 1 below. The pH of the reactor was maintained using sodium bicarbonate buffer (pH 7.9), 200 mg / L of NaCl and 200 mg / L of (NH ₄ Cl) ₂ HPO ₄ were added. In order to homogeneously mix the inside of the reactor, it was continuously mixed in an upward flow using a circulation pump and the change value was monitored through pH meter and OPR probe. A wet gas-meter (Model W-NK-0.5, Shinagawa, Japan) was used to measure the emission capacity of the gas generated in the reactor. A GC-TCD The nature of the product gas was analyzed and the organic acid present in the reactor solution was sampled at the sampling port in the circulation line and pretreated and measured using GC-FID.

Furtherance Concentration (mg / l) MgCl ₂ .6H ₂ O 16.05 CaCl ₂ .2H ₂ O 1.20 ZnCl ₂ 5.91 Na ₂ Mo · 2H ₂ O 1.29 MnCl ₂ .4H ₂ O 13.19 CuCl ₂ .2H ₂ O 2.61 CoCl ₂ .6H ₂ O 0.3 KCl 1.00 FeCl ₂ .2H ₂ O 5.23 EDTA 9.75 Phosphate buffer solution (pH 7) 1M

1 shows the pressure change and the pH change with the operation time. As shown in FIG. 1, the system was operated under neutral conditions of pH 6.5 to 7.5, and the mixed gas supply pressure was increased from 0.2 to 0.3 atmospheres to 0.4 atmospheres at 90 and 0.5 atmospheres at 115 days. The reaction temperature was maintained at 37 ℃ and the ORP was -390mV, which was slightly higher than -450mV, which is suitable for microbial activity, but anaerobic conditions remained stable during the operation. The reaction mixture was circulated in an upflow manner at a circulation rate of 84 ml / min, thereby maintaining a completely mixed state. The circulation rate was maintained without any significant change, and the operating conditions between the two reactors were kept the same as possible, but only the pH state was changed and the changes were observed. Figure 2 shows the amount of organic acid produced. As shown in FIG. 2, the amount of acetic acid produced during the initial operation was in the range of 1000-2400 ppm, and the amount of acetic acid was slightly decreased in the range of 500-1500 ppm from the 60th day of operation. It is believed that acetic acid is continuously produced while the acetic acid-producing microorganism (acetogen) occupies a part of whole microbial community without being inhibited by operation at a neutral pH.

[Example 2] Ethanol production using a hollow fiber bioreactor

A hollow fiber membrane having the same conditions as in Example 1 was used and the microorganisms to be seeded were replaced with ethanol producing microorganisms. A hollow fiber bioreactor with an effective volume of 195 ml was operated under the condition of pH 5 ~ 8 by loading 1,000 strands of polysulfone hollow fibers inside an acrylic reactor with a total volume of 1.3 liters. In order to maintain the internal temperature of the hollow fiber membrane reactor, the hose was wound around the outside, and the temperature was adjusted to 35 to 38 ° C by circulating hot water in the hose by using a heating circulator. A mixed gas composed of carbon dioxide and hydrogen at a volume ratio of 1: 4 was injected into the hollow fiber membrane and maintained at about 0.2 to 0.3 atmospheric pressure on the pressure gauge and increased to 0.5 atmospheric pressure in the latter half, To the extent of change. Ethanol-producing microorganisms were seeded at a ratio of 20% (v / v) of the effective volume. The micronutrients in the culture were as shown in Table 1 and the pH of the reactor was maintained using sodium bicarbonate buffer (pH 7.9). 200 mg / L of NaCl and 200 mg / L of (NH ₄ Cl) ₂ HPO ₄ were added. In order to homogeneously mix the inside of the reactor, it was continuously mixed in an upward flow using a circulation pump and the change value was monitored through pH meter and OPR probe. A wet gas-meter (Model W-NK-0.5, Shinagawa, Japan) was used to measure the emission capacity of the gas generated in the reactor. A GC-TCD The nature of the product gas was analyzed and the organic acid present in the reactor solution was sampled at the sampling port in the circulation line and pretreated and measured using GC-FID. Alcohol was analyzed by HPLC.

After 5 days of inoculation, ethanol was produced and the concentration of ethanol was about 7 ~ 10 g / L. After 15 days of operation, the concentration of ethanol was 30 ~ 50 g / L.

The ethanol - producing microorganisms were stably immobilized on the used desert carrier, so that they did not lose their activity even after one month of continuous operation and no microbial desorption was found. Ethanol concentration was stable to 50 ~ 70g / L. The production rate of ethanol was 1.3 ~ 2 g / L / hr.

[Example 3] Acetic acid extraction and distillation

100 mL of water and 20 g of this acetic acid were mixed in a 500 mL beaker, 75 g of tripentine amine as an extraction solvent was added, and the mixture was stirred vigorously for 1 hour and then left to stand for complete layer separation. After 1 hour, the concentration of acetic acid remaining in the water layer was 0.1%, and 99% or more of the charged acetic acid was transferred to the extraction solvent layer.

Acetic acid dissolved in the extraction solvent layer recovered from the beaker was placed in a batch distillation apparatus, and while the pressure was maintained at 30 torr with stirring, the temperature was gradually increased at intervals of 10 ^° C. From the point at which the temperature reached 90 ^° C, Steam was introduced into the condenser and the distiller temperature was fixed at 100 ^° C. When the acetic acid vapor entering the condenser was no longer introduced, the distiller operation was stopped and 17 g of acetic acid was recovered in the condenser.

[Example 4] Esterification reaction of acetic acid and ethanol

For the esterification reaction of acetic acid and ethanol, Amberlyst-121 Wet was filled in a 12 mm tubular reactor to 80 mL, and the temperature was maintained at 110 ^° C. A raw material in which acetic acid and ethanol were mixed at a molar ratio of 1: 2 was fed into the reactor at a rate of 100 g per hour. Reactants and by - products were collected from 5 hours to 10 hours and analyzed.

The collected reactant was 920 g and 75 g of water was obtained. As a result of analyzing the composition of the collected reactants and byproducts, it was confirmed that the conversion of acetic acid was 98% or more and ethyl acetate was produced as an ester compound through the esterification reaction.

[Example 5] Hydrolysis of ethylacetate

12.0 cc of an inner diameter 12 mm tubular continuous reactor was charged with 12.0 cc of a commercial catalyst for aqueous gas conversion reaction (CuZnOx / gamma alumina, CuO 51 wt%, ZnO 31 wt%, alumina: balance) ^o C for 3 hours at 220 ^° C for 2 hours with 20% by volume hydrogen and nitrogen gas mixture. Ethyl acetate was fed at 2.0 cc / hr and hydrogen was fed at 10 L / hr. The temperature of the catalyst bed was maintained at 150 ^° C and the pressure at the rear end of the reactor was kept at 10 bar. The product was sampled at 6 hour intervals from the point of time when the reactor reached steady-state operation and analyzed by GC-FID.

Changing the temperature of the catalyst layer to 175 ^o C, 200 ^o C and then, as a result of the experiment under the same conditions is 150 ^o the conversion of ethyl acetate to 85% C, 175 ^o C in was 93%, and 200 ^o C 95% The selectivity for ethanol was more than 99.8% regardless of temperature condition.

FIG. 1 shows a pressure change and a pH change according to an operation time in an embodiment of the present invention.

Figure 2 shows the amount of organic acid produced in one embodiment of the present invention.

Claims (9)

A method for producing bio-alcohols from flue-gas and syngas, A step of supplying an exhaust gas and syngas to the inner pores of the hollow fiber membrane at a constant pressure and attaching a microorganism producing an organic acid or a bio alcohol to the outer wall of the hollow fiber membrane to fix the organic acid or alcohol; The produced organic acid is supplied to a liquid-liquid extraction tower and extracted using an extraction solvent. The bioalcohol produced directly by the microorganism is extracted from the culture broth, separated and distilled to produce an organic acid mixed with the extraction solvent. Distilling the organic acid and the extraction solvent into a distillation tower, and then re-supplying the separated extraction solvent as an extraction solvent for extracting the organic acid; And Separating and purifying the produced alcohol as a final product or using a part of the produced alcohol as a hydrogenation decomposition reaction additive of an organic acid, The step of using a part of the produced alcohol as an addition product of hydrocracking reaction of an organic acid, Mixing the alcohol with the organic acid extracted and distilled / recovered, converting the alcohol into an ester compound through an esterification reaction process or converting it into an alcohol through a hydrocracking reaction process to obtain an alcohol as an end product; A predetermined portion of the ester compound is obtained as an end product and the remainder is supplied to a hydrocracking reactor to convert to an alcohol; And Wherein the alcohol and the microorganism obtained through the hydrocracking reaction are directly produced, and a predetermined portion of the alcohol obtained through the separation and purification process is obtained as a final product and the remainder is used for the esterification and hydrocracking reaction, The hydrocracking reaction is carried out at a reaction temperature of 110 to 350 ^° C and a reaction pressure of 1 to 70 bar using a catalyst having a hydrogenation function in which one or two or more metal oxides are supported on a support, Wherein the metal oxide is selected from the group consisting of copper oxide, zinc oxide, chromium oxide, nickel oxide, cobalt oxide, molybdenum oxide, tungsten oxide, A method for producing bio-alcohols from flue-gas or syngas. The method according to claim 1, wherein the microorganism producing organic acid or bio-alcohol is fed into the hollow fiber membrane immobilized on the outer wall, and the hollow fiber membrane is immersed in a nutrient- A method for producing a bio-alcohol from an exhaust gas or syngas characterized by producing alcohol. delete delete delete delete The method according to claim 1, wherein the organic acid or ethanol producing microorganism is Clostridium genus, Eubacterium limosum, Peptostreptococcus productus, Oxobacter pfennigii, Acetobacterium woodii, Butyribacterium methylotrophicum, Methanosarcina acetivorans, Moorella thermoacetica or Moorella thermoautotrophica . A method for producing alcohol. The method according to claim 1, wherein the organic acid and the ethanol-producing microorganism are suspended or suspended on the outer wall of the hollow fiber membrane to produce an organic acid or ethanol while floating. The method according to claim 1, wherein the bioalcohol is ethanol, butanol, ethyl acetate, butyl acetate, butylbutyrate or a mixture of ethanol and ethyl acetate.

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