KR101255015B1 - Rotating Disk Reactor for Synthesis Gas Fermentation and Method for Running the Same - Google Patents

Abstract

The present invention relates to a rotating disk-type bioreactor for fermenting syngas to produce ethanol, organic acid and the like and a method of operating the same. More particularly, the present invention relates to an apparatus and a method of operating the same for improving the contact of syngas with very low solubility gas and microbial growth and product production rate.
According to the present invention, in a rotary disk-type bioreactor capable of causing an anaerobic fermentation reaction using a synthesis gas containing carbon monoxide and hydrogen as a gas substrate, a reactor body capable of reacting the microorganisms in the gas substrate and the liquid medium may react. ; A plurality of rotating discs fitted to a rotating shaft installed in the reactor body in the longitudinal direction; And a magnetic drive transmitting power to the rotating shaft so that the plurality of rotating disks can rotate. Includes, the inside of the reactor body is a gas substrate to fill the remaining space in the state in which the liquid medium is filled in the bottom, while rotating the plurality of rotating disks the microorganisms in the liquid medium and the gas substrate is in contact with the synthesis gas Rotary disk type bioreactor may be provided, characterized in that the fermentation of.

Description

Rotating Disk Reactor for Synthesis Gas Fermentation and Method for Running the Same

The present invention relates to a rotating disk-type bioreactor for fermenting syngas to produce ethanol, organic acid and the like and a method of operating the same. More particularly, the present invention relates to an apparatus and a method of operating the same for improving the contact of syngas with very low solubility gas and microbial growth and product production rate.

When combustible materials are burned in a condition less than the theoretical air amount, they are incompletely burned to generate a combustible gas such as carbon monoxide (CO) or hydrogen (H ₂ ), and this reaction is called gasification. Maintaining this reaction while maintaining a high temperature yields 5-8 MJ / Nm ³ of low calorific syngas. The main components of the synthesis gas include flammable gases such as carbon monoxide, hydrogen and trace methane, carbon dioxide, and nitrogen.

Carbon monoxide and hydrogen in syngas are used to synthesize organic compounds through the Fischer-Tropsch process. In such chemical processes, it is important to purify carbon monoxide and hydrogen to a certain level or more. In contrast, in biological processes, organic acids such as ethanol and acetic acid can be obtained by using carbon monoxide and hydrogen as substrates without a high level of separation process. Strains involved in this process are disclosed in Patent Registration No. 10-0634835, and the like, and techniques for enhancing the production of ethanol are disclosed in Patent Registration No. 10-0879577 and the like.

There are various methods or reactors for supplying the gas substrate, such as a continuous stirring tank, a bubble reactor, a biofilm carrier reactor, a water spray phase reactor, a microbubble mixing reactor, and a membrane reactor. The characteristics of these methods are as follows.

Continuous Stirred-Tank Reactor (CSTR) is the most commonly used reactor for syngas fermentation. Here the gaseous substrate is continuously injected and the nutrients necessary for the growth of the microorganisms are also fed together in the liquid medium. The fermentation broth is withdrawn at the same flow rate as the liquid medium to be injected. It is common to use an impeller to ensure that the gaseous substrate is sufficiently supplied to the microorganisms.

Bubble column reactor is mainly developed for industrial use, which has the advantages of large volume, large substrate feeding speed, and relatively low maintenance cost. On the other hand, it is a disadvantage that bubbles are combined and the efficiency is low.

In the biofilm carrier reactor, a gaseous substrate is supplied so as to be able to contact microorganisms growing on the carrier surface. At the surface of the carrier, the microorganisms receive a substrate and produce ethanol and acetic acid. Gas substrates are relatively competitive because they are supplied at atmospheric pressure.

In the trickle-phase reactor, the liquid medium is sprinkled in the bed filled with the filter medium, and the synthesis gas is supplied downward or upward. Since no mechanical mixing is required, the power consumption is relatively low compared to the CSTR reactor.

The microbubble mixing reactor is a reactor in which microbubbles are supplied, and has a form of a general stirred-tank reactor. A reactor based on the principle that the solubility of the gas increases as the diameter of the bubble is smaller, a device for making microbubbles should be included.

Hollow fiber membranes in the membrane reactor can be used to dissolve the gas in the liquid medium. Syngas can be supplied to the medium without the generation of bubbles, and microorganisms attach and grow on the outer surface of the membrane. It is known to show higher productivity and reaction rate than other reactors, and is relatively less affected by inhibitors such as tar and nitrogen oxides contained in syngas. When operating at higher pressures, the mass transfer rate is faster, which makes the reactor smaller in size.

On the other hand, in syngas fermentation, in order to increase the growth rate of microorganisms or materials, it is necessary to effectively supply the syngas used as a substrate. Solubility of carbon monoxide and hydrogen, the main components of the synthesis gas, is very low, and attempts have been made using microbubbles, mechanical stirring, hollow fiber membranes, but the difference is not clear.

The present invention for solving the above problems, to provide a rotary disk-type bioreactor for syngas fermentation that can effectively supply a gaseous substrate of low solubility to microorganisms and its operating method.

According to the present invention for achieving the above object, in the rotating disk-type bioreactor capable of causing an anaerobic fermentation reaction using a synthesis gas containing carbon monoxide and hydrogen as a gas substrate, the microorganisms in the gas substrate and liquid medium A reactor body capable of reacting; A plurality of rotating discs fitted to a rotating shaft installed in the reactor body in the longitudinal direction; And a magnetic drive transmitting power to the rotating shaft so that the plurality of rotating disks can rotate. Includes, the inside of the reactor body is a gas substrate to fill the remaining space in the state in which the liquid medium is filled in the bottom, while rotating the plurality of rotating disks the microorganisms in the liquid medium and the gas substrate is in contact with the synthesis gas Rotating disk-type bioreactor is provided, characterized in that the fermentation of.

It is preferable that the rotating disc is provided with a porous portion so as to form a film in which microorganisms can grow efficiently.

In order to maintain a constant internal temperature of the reactor body in the course of the fermentation it is preferable that a heating heater is installed on the outer wall of the reactor body.

The material of the rotating disc is preferably one coated with Teflon on a metal or Teflon.

The material of the reactor body is preferably stainless steel (stainless steel) or acrylic.

The reactor body is preferably formed with a sight hole that can visually confirm the reaction occurring in the reactor body.

It is preferable that the separating plate is fitted between the rotating discs so as not to contact the rotating discs through the rotating shaft.

According to another aspect of the present invention, a method of operating a rotating disk-type bioreactor comprising the steps of sterilizing the inside of the reactor body of the rotating disk-type bioreactor; Supplying nitrogen gas into the reactor body after the sterilization to make the reactor body anoxic; Filling a liquid medium in the lower portion of the reactor body in sterile and anoxic conditions and filling a gas substrate in the remaining space; And rotating the rotating disk of the rotating disk-type bioreactor, wherein the microorganisms in the liquid medium and the gas substrate are in contact with each other to ferment the syngas. There is provided a method of operating a rotating disk-type bioreactor comprising a.

In the step of the fermentation of the synthesis gas, it is preferable that the supply of the gas substrate is further made in consideration of the pressure inside the reactor body.

In the step of fermentation of the synthesis gas, it is preferable to filter the microorganisms in the liquid medium to maintain a constant concentration of microorganisms in the liquid medium.

According to the present invention as described above, it is not necessary to operate at high pressure to increase the solubility of the gas substrate for the syngas fermentation, and mechanical agitation is not required to supply fine bubbles, it is possible to reduce the operation and equipment costs.

In addition, according to the present invention, since the substrate supply rate is high, there is an advantage in that the growth rate of microorganisms and the product generation rate such as ethanol are fast.

1 is a front cross-sectional view of a rotating disk-type bioreactor for syngas fermentation according to the present invention.
Figure 2 is a plan view of a rotating disk-type bioreactor for syngas fermentation in accordance with the present invention.
Figure 3 is a side view of a rotary disk-type bioreactor for syngas fermentation in accordance with the present invention.
4 is a view showing a rotating disc.
Figure 5 is a flow chart showing the operation method of the rotary disk-type bioreactor for syngas fermentation according to the present invention in the order of time.

Hereinafter, a rotary disc bioreactor for syngas fermentation according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Microorganisms used in the synthesis gas fermentation experiment according to a preferred embodiment of the present invention are Clostridium ljungdahlii purchased from ATCC in the United States and Clostridium autoethanogenum purchased from DSMZ in Germany, both produce ethanol and acetic acid.

Synthesis gas used in the preferred embodiment of the present invention may include carbon monoxide and hydrogen as a main component, and may include trace amounts of methane, carbon dioxide, nitrogen, and the like which are combustible gases. In addition, the synthesis gas is used as a gas substrate to cause an anaerobic fermentation reaction.

1 is a front cross-sectional view of a rotating disk-type bioreactor for syngas fermentation according to a preferred embodiment of the present invention.

As shown in FIG. 1, a plurality of rotating discs 10 are fitted in the reactor body 12 along the rotating shaft 13 installed in the longitudinal direction. Although not shown in the drawings, the separating plate may be inserted through the rotating shaft 13 between the plurality of rotating discs 10 so as not to contact the rotating discs 10. At this time, the outer diameter of the separator is preferably slightly larger than the outer diameter of the rotary shaft (13). This is because when the outer diameter of the separating plate is too large, some of the porous portions 15 (see FIG. 4) formed in the rotating disc 10 may be blocked. Teflon or the like may be used as a material of the separator.

In the reactor body 12, microorganisms in the gas substrate injected through the gas inlet 2 and the liquid medium injected through the liquid medium inlet 3 (see FIG. 2) react to cause fermentation of the synthesis gas. At this time, the rotating disc 10 may be formed with a porous portion (15, see Fig. 4) consisting of a plurality of holes to increase the contact efficiency of the liquid medium and the gas substrate and to form a film to grow microorganisms efficiently.

The rotating disc may be made of metal coated with Teflon or Teflon.

The rotating shaft 13 may receive power through the magnetic drive 1 so that the plurality of rotating disks 10 can rotate. Since the magnetic drive 1 is used as a power source, even if the rotating disc 10 rotates during the fermentation process of the syngas, the leakage of gas can be effectively blocked.

A heating heater 9 may be installed on the outer wall of the reactor body 12 in order to maintain a constant internal temperature of the reactor body 12 during the fermentation of the syngas. In addition, a temperature sensor (not shown) may be installed through the temperature sensor connecting portion 4 located at one side of the reactor body 12 to measure the internal temperature.

In addition, it is necessary to maintain the internal pressure of the reactor body 12 at an appropriate level in the course of the fermentation of the synthesis gas. This is because the reaction between the gas substrate and the microorganism can occur efficiently at a certain level or more. To this end, since it is necessary to measure the internal pressure of the reactor body 12, a pressure sensor (not shown) may be installed at the pressure sensor connection part 5 located at one side of the reactor body 12.

The material of the reactor body 12 may be stainless steel or acrylic. Especially, when using a metal material such as stainless steel, it is difficult to visually check the reaction inside the reactor body 12. One side of the 12 may be provided with a sight hole (11).

Through the gas outlet 6 located at one side of the reactor body 12 to discharge the gas inside the reaction after a predetermined time.

Referring to FIG. 2, the gas inlet 2, the liquid medium inlet 3, the temperature sensor connection 4, the pressure sensor connection 5, the gas outlet 6 and the see-through 11 are more clearly described. I can figure it out.

Referring to FIG. 3, it can be seen that the liquid medium outlet 7 and the liquid medium filtration outlet 8 are formed on the side of the reactor body 12.

The liquid medium can be obtained through the liquid medium outlet 7 for the component analysis of the liquid medium after the fermentation process of the syngas.

Through the liquid medium filter outlet 8, the microorganisms in the medium can be filtered out to maintain a constant concentration of the microorganisms. In addition, it is possible to recover the product obtained through the syngas fermentation in the liquid medium, the liquid medium can be fed back to the liquid medium inlet (3).

Hereinafter, a method of operating a rotating disc bioreactor for syngas fermentation according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figure 5 is a flow chart showing the operating method of the rotary disk-type bioreactor for syngas fermentation according to the present invention in the order of time.

Prior to operating the above-described rotating disk-type bioreactor, the interior of the reactor body 12 is first sterilized. (S100) After sterilization, gas inside the reactor body 12 to make the inside of the reactor body 12 anoxic condition. Nitrogen gas is supplied through the injection port 2 to purify the inside of the reactor body 12. (S200)

For example, after sterilizing in a high-pressure sterilizer, the inside of the reactor body 12 may be sufficiently sterilized with 99% of ethanol on a disinfecting cotton, and then irradiated with an ultraviolet lamp for 24 hours, and then the reactor body 12 may be sealed. have. Thereafter, nitrogen may be injected after passing through a 0.25 μm filter to remove oxygen therein.

The reactor body 12 in sterile and anoxic conditions may be filled with a liquid medium through the liquid medium inlet 3 and inject microorganisms. In a state in which a certain amount of the liquid medium is filled in the lower part of the reactor body 12, the remaining space may be filled with the synthesis gas as a gas substrate through the gas inlet 2 (S300).

For example, the liquid medium may be filled up to the height of the rotating shaft 13 and inoculated with microorganisms. In addition, the synthesis gas may be injected until the pressure reaches about 1 to 5 atm through an inlet connected with a 0.25 μm filter and a needle valve.

When the magnetic drive 1 is driven, the rotating disc 10 connected thereto rotates to allow the microorganism and the gaseous substrate in contact with the liquid medium to come into contact with the fermentation of the syngas.

At this time, since the reaction may occur effectively when the internal pressure of the reactor body 12 is greater than or equal to a predetermined level, the gas substrate 2 may be properly supplied with the gas inlet.

Temperature and pressure are measured at 1 minute intervals using K-type thermocouples, pressure sensors, Labview ™ and NI9219 data acquisition devices. Samples for measuring the synthesis gas composition and the concentration of the product in the culture medium are collected while observing the condition and pressure change of the reactor. The growth rate of microorganisms is determined by measuring the concentration at 600 nm using a spectrophotometer of the collected culture solution.

As a result of operating the rotary disk-type bioreactor, the OD value is about 2 times higher than that of the conventional 500 ml Pyrex foam gas cycle type bioreactor. In addition, the rotating disk-type bioreactor exhibits a growth rate more than twice that of the conventional bubble reactor.

According to the rotating disk-type bioreactor as described above, since the substrate is reacted with the microorganisms using the rotating disk, the contact area between the microorganism and the gas substrate is wide and the reaction can be efficiently performed.

As described above, the rotating disk-type bioreactor for syngas fermentation according to the present invention and a method of operating the same are described with reference to a preferred embodiment of the present invention. However, it should be understood that the present invention is not limited to the above-described embodiments and drawings, and various modifications and changes may be made by those skilled in the art without departing from the scope of the present invention.

1: magnetic drive 2: gas inlet
3: liquid inlet port 4: temperature sensor connection
5: Pressure sensor connection 6: Gas outlet
7: Liquid medium outlet 8: Liquid medium filtration outlet
9: heating heater 10: rotating disc
11: sight hole 12: reactor body
13: axis of rotation 15: hole

Claims (10)

In a rotary disk-type bioreactor in which an anaerobic fermentation reaction is caused by using a synthesis gas containing carbon monoxide and hydrogen as a gas substrate,
A reactor body capable of reacting the gas substrate with the microorganisms in the liquid medium;
A plurality of rotating discs fitted to a rotating shaft installed in the reactor body in the longitudinal direction;
A porous part provided in the rotating disc to form a film in which microorganisms can efficiently grow;
A separating plate inserted between the plurality of rotating discs through the rotating shaft, the outer diameter of which is greater than the outer diameter of the rotating shaft but is formed so as not to block the porous part;
A temperature sensor installed through a temperature sensor connection part located at one side of the reactor body to measure the internal temperature of the reactor body;
A pressure sensor installed through a pressure sensor connection part located at one side of the reactor body to measure the internal pressure of the reactor body;
A gas inlet installed at one side of the reactor body to inject a gas substrate into the reactor body;
A liquid medium injection port installed at one side of the reaction tank body to inject a liquid medium into the reactor body;
A liquid medium discharge port installed at a side of the reaction tank body in order to discharge the liquid medium after the fermentation process of the synthesis gas in the reactor body;
A liquid medium filtration outlet provided at a side of the reactor body to filter out microorganisms in the medium in the reactor body; And
And a magnetic drive transmitting power to the rotating shaft so that the plurality of rotating disks can rotate.
In the reactor body, the gas substrate fills the remaining space in the state where the liquid medium is filled in the lower portion, and the microorganisms in the liquid medium and the gas substrate are in contact with each other by rotating the plurality of rotating discs, so that the synthesis gas is fermented. Rotating disk-type bioreactor, characterized in that. delete The method according to claim 1,
Rotating disk type bioreactor, characterized in that the heating heater is installed on the outer wall of the reactor body in order to maintain a constant internal temperature of the reactor body in the course of the fermentation. The method according to claim 1,
Rotating disc type bioreactor, characterized in that the material of the rotating disc is coated with Teflon on the metal or Teflon. The method according to claim 1,
Rotating disk-type bioreactor, characterized in that the material of the reactor body is stainless steel (stainless steel) or acrylic. The method according to claim 1,
Rotating disk-type bioreactor, characterized in that the seeker is formed in the reactor body to visually check the reaction occurring in the reactor body. delete In the operating method of the rotating disk-type bioreactor,
Sterilizing the inside of the reactor body of the rotating disk-type bioreactor according to any one of claims 1 and 3 to 6.
Supplying nitrogen gas into the reactor body after the sterilization to make the reactor body anoxic;
Filling a liquid medium in the lower portion of the reactor body in sterile and anoxic conditions and filling a gas substrate in the remaining space; And
Rotating the rotating disk of the rotating disk-type bioreactor, wherein the microorganisms in the liquid medium and the gas substrate are in contact with each other so that the syngas is fermented;
Rotating disk-type bioreactor operating method comprising a. The method according to claim 8,
In the step of the fermentation of the synthesis gas, the operation method of the rotary disk-type bioreactor, characterized in that the supply of gas substrate is further made in consideration of the pressure inside the reactor body. The method according to claim 8,
In the step of the fermentation of the synthesis gas, the method for operating a rotating disk-type bioreactor, characterized in that to filter the microorganisms in the liquid medium to maintain a constant concentration of the microorganisms in the liquid medium.

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