KR100898385B1 - Method for producing hydrogen gas from marine algae using anaerobic microorganisms - Google Patents

Abstract

The present invention relates to a method for producing hydrogen gas from algae using anaerobic microorganisms, and more particularly to a method for producing hydrogen gas from seaweeds in an environmentally friendly manner by treating the seaweeds under optimal processing conditions and reaction conditions. It is about.

Algae, hydrogen gas

Description

Production method of hydrogen gas from seaweed using anaerobic microorganism {METHOD FOR PRODUCING HYDROGEN GAS FROM MARINE ALGAE USING ANAEROBIC MICROORGANISMS}

The present invention relates to a method for producing hydrogen gas from algae using anaerobic microorganisms.

Bioenergy refers to an energy source made from biomass such as animals, plants, and microorganisms, and is also called biomass energy.

In the method of using such a biomass as an energy source, in the past, a method such as direct combustion was mainly used, but today, organic matter or organic waste is 1) biochemical conversion process using enzymes or microorganisms; 2) photobiological conversion process using photosynthetic microorganisms; And 3) producing liquid fuels such as ethanol, methanol, biodiesel, Fischer-Tropsch diesel, and / or gaseous fuels such as hydrogen, methane, etc. through thermochemical conversion processes using thermal energy and chemical catalysts. The way is this week. The energy source obtained from such a recent biomass utilization method is called the biomass energy, and the biomass energy source is advantageous in that it can be stored and regenerated and is environmentally safe.

Hydrogen in these biomass energies generates little pollutants, except for very small amounts of nitrogen generated during combustion, and is very easy to use as fuel for direct combustion and fuel cells. The availability is very high.

So far, hydrogen has been obtained by pyrolysis of naphtha, electrolysis of water, and biological methods using photosynthetic and / or anaerobic microorganisms, but pyrolysis of naphtha and electrolysis of water are associated with the use of fossil fuels that are at risk of depletion. Due to the large amount of carbon dioxide, a global warming material in fuel, it is not an environmentally friendly process. In the biological method, when hydrogen is produced using photosynthetic microorganisms, 1) the growth rate of microorganisms is slow; 2) requires constant light energy; 3) It is economically expensive because it requires a large area to obtain light energy; And 4) it is difficult to stably grow microorganisms when the temperature change is large (Tanisho, S. and Ishwata, Y., J. Hydrogen energy, 19: 807-812 (1994)).

At present, although limited, the treatment of manure, municipal waste, and wastewater by methane fermentation or activated sludge process has led to the development of energy-saving methods for obtaining additional energy along with wastewater or waste treatment.

In relation to the production of energy using biomass, Brazil collects alcohol from sugar cane and cassava and uses it as fuel for automobiles, while the world is focusing on energy production using biomass such as plants and microorganisms. As the land area is narrow, it is difficult to obtain a large amount of biomass, so it is most important to develop a method for acquiring new biomass suitable for Korea's situation and converting it into renewable energy.

Therefore, the technical problem to be achieved by the present invention is to overcome the disadvantages of the prior art as described above, and to provide a method for producing hydrogen gas from biomass (biomass) in an eco-friendly and efficient manner suitable for the environment of our country.

In order to solve the above problems, the present invention provides a method for producing hydrogen gas from seaweeds that are abundant in the world's oceans using anaerobic microorganisms.

More specifically, the present invention

a) treating the algae;

b) preparing a mixture by mixing the seaweed and the anaerobic microorganism or the reaction solution containing the anaerobic microorganism performing step a); And

c) fermenting the mixture at 20 to 60 ° C. and anaerobic conditions.

It relates to a production method of hydrogen gas.

Since Korea has a narrow land area and a temperate climate with four seasons, it is not suitable for the mass production of land plants and it is difficult to obtain a large amount of biomass on land, but it can grow only by the geographical conditions of the sea on three sides and by water and sunlight alone. In addition, there is a large amount of seaweed that grows much faster than land plants, which has the advantage of being used as a new biomass for producing biomass energy, a renewable energy.

In addition, the inventors of the present invention, due to the difference in the composition and structure of the algae, the production of hydrogen gas is different depending on the reaction temperature, reaction time and treatment process for each seaweed, the optimum reaction temperature, the optimum treatment process for each seaweed And when producing hydrogen gas under the conditions of the optimum reaction time, it was confirmed that the excellent production yield was completed the present invention.

In fact, as a result of attempting the production of hydrogen gas under the optimum reaction conditions described in the embodiments of the present invention described below, the present invention was confirmed by confirming an excellent production yield.

Hereinafter, the present invention will be described in detail.

In the present invention, biomass refers to organic matters such as living animals, plants, and microorganisms, and is also referred to as biomass or biomass ecologically, and preferably refers to seaweeds.

In the present invention, the activated sludge method is a biological treatment method for purifying sewage and wastewater using microorganisms, and generally uses a wastewater treatment apparatus including a flow adjusting tank, an aeration tank, a precipitation tank, a conveying tank and a discharge tank.

In the present invention, algae means sea algae, which includes green algae, brown algae and red algae. The algae can grow only by water and sunlight among the biomass, and the growth rate is much faster than that of the crops, and since it exists abundantly in the sea above all, the three sides are the most abundant in Korea considering the geographical conditions of Korea. It can be said that it corresponds to biomass.

The algae of step a) may be green algae, brown algae and algae, and the green algae may be, for example, seaweed, chlorella (cheongtae) or hearing, and the brown algae may be, for example, seaweed, kelp, 톳, rhubarb or maize. , The red algae may be, for example, laver, barley fern or carrageenan. The seaweed may be at least one selected from the group consisting of seaweed, chlorella, seaweed, seaweed and kelp, preferably at least one selected from the group consisting of seaweed, seaweed and kelp, more preferably kelp. .

Treatment of the seaweed of step a) is a grinding treatment; Heat treatment under conditions of 100 to 140 ° C; Sonication at 15-25 kHz conditions; Acid treatment with 0.1-1.8 N acid; And it can be carried out by one or more treatment method selected from the group consisting of alkali treatment with 0.1 to 1.8 N alkali.

The pulverizing treatment may be performed by a conventional method of pulverizing algae, and may be a mixer or a pulverizer.

In addition, the heat treatment may be performed for 15 minutes to 45 minutes, preferably 25 to 35 minutes under conditions of 100 to 140 ℃, more preferably 110 to 130 ℃. When the heat treatment under the conditions of 100 to 140 ℃, compared to the heat treatment under the conditions of 60 ℃, it was confirmed that there is a yield improvement of about 20% (Kashima) to about 150% (kim) (Table 4 and Table 3), when the treatment at a high temperature above the above temperature range, waste of energy input is large, in order to use anaerobic microorganisms, it is not economical because it takes a lot of time to cool the high-temperature seaweed to a low temperature.

In addition, the ultrasonic treatment may be performed for 20 to 40 minutes, preferably 25 to 35 minutes under the condition of 15 to 25 kHz, preferably 19 to 21 kHz using a sound processor. When the ultrasonic treatment is treated in the time range, it was confirmed that there is a yield improvement of about 10% compared to the case of treatment for 15 minutes (Tables 2 to 4).

The acid treatment may use an acid or acid solution of 0.1 to 1.8 N. In addition, the alkali treatment may use an alkali or an alkaline solution of 0.1 to 1.8 N.

In the case of the acid treatment and the alkali treatment, due to differences in the constituents and tissue structure of the seaweeds, the optimum concentration of the acid and alkali treated for each seaweed is different.

As an example, when the seaweed is green and treated with an acid or acid solution of 0.1 N to 0.5 N, preferably 0.2 N to 0.4 N, it is about 50 compared with the case of treating with 1.6 N acid or an acid solution. It was confirmed that there is a yield improvement of% (Table 2). Also, when the seaweed is green and treated with an alkali or alkaline solution of 1.4 N to 1.8 N, preferably 1.5 N to 1.7 N, it is about 10% compared with the case of treating with 0.3 N alkali or alkaline solution. It was confirmed that the yield improvement of (Table 2).

Further, when the seaweed is seaweed, and treated with an acid or acid solution of 1.2 N to 2.0 N, preferably 1.4 N to 1.8 N, compared with the case of treating with 0.3 N or 0.9 N acid or acid solution, It was confirmed that there is a yield improvement of about 320% or about 160% (Table 3). In addition, when the seaweed is seaweed, and treated with an alkali or alkaline solution of 1.4 N to 1.8 N, preferably 1.5 N to 1.7 N, it is about 30% compared to the case of treatment with 1 N alkali or alkaline solution It was confirmed that the yield improvement of (Table 3).

In addition, when the seaweed is kelp, and treated with an acid or acid solution of 0.1 N to 0.5 N, preferably 0.2 N to 0.4 N, about 40% compared to the case of treatment with 1.0 N acid or acid solution It was confirmed that the yield improvement of (Table 4). In addition, when the seaweed is kelp, and treated with an alkali or alkaline solution of 1.4 N to 1.8 N, preferably 1.5 N to 1.7 N, about 40% compared to the case of treatment with 1 N alkali or alkaline solution It was confirmed that the yield improvement of (Table 4).

The step b) may be performed by mixing the seaweed and the anaerobic microorganism or the reaction solution containing the anaerobic microorganism performing the step a) to prepare a mixture.

The anaerobic microorganism is not particularly limited in the case of a microorganism capable of smoothly performing metabolic processes in anaerobic conditions, preferably the anaerobic microorganism is Clostridium butylicum ), Clostridium pasteurianum ), Clostridium kluyveri , Diplococcus glycinophilus ), Escherichia coli), Bacillus miksa poly (Bacillus polymyxa ), Aeromonas hydrophila hydrophila ), Bacillus maserans macerans ), Desulfovibrio , Desulfuricans , Nonsulfur Purple Bacteria purple bacteria , Methylotrophs , Methanogenic bacteria , Rumen bacteria), the microorganism may be one or more member selected from the group consisting of Al kaeah (Archaea) and Enterobacter (Enterobacter). In the case of anaerobic microorganisms, hydrogen is preferably produced from biomass in that it is faster in speed than in fermentation processes using photosynthetic microorganisms, generates a large amount of hydrogen, and does not require light energy.

The anaerobic microorganism is an example of using activated sludge in sewage at 1 ° C to 10 ° C, preferably 2 to 7 ° C, more preferably 3 to 5 ° C, and 500 to 5,000 rpm, preferably 1,000 to 3,000 After centrifugation for 1 to 10 minutes, preferably 3 to 7 minutes under the conditions of rpm, it can be obtained by separating the supernatant of the activated sludge of the sewage to perform the centrifugation. The activated sludge of the sewage may be activated sludge obtained during the anaerobic sewage treatment process.

The reaction solution containing the anaerobic microorganism may be a culture cultured the anaerobic microorganism, for example, by adding the anaerobic microorganism obtained by separating the supernatant of the activated sludge to perform the centrifugation to culture medium Can be.

Step c) may be performed by fermenting the mixture prepared in step b) at a reaction temperature of 20 to 60 ° C. and anaerobic conditions.

The anaerobic condition may be, for example, an oxygen content of 5% or less, preferably 3% or less, and more preferably 1% or less, and the anaerobic condition may inject nitrogen gas into a culture vessel including the mixture. Can be obtained by removing oxygen. The method of removing oxygen may be performed by, for example, a method of removing oxygen by injecting the nitrogen gas for 10 to 30 minutes, but is not limited thereto.

As mentioned above, since seaweeds have different constituents and tissue structures, the optimum reaction temperature of step c) is different for each seaweed.

For example, when the seaweed is green, preferably the mixture may be fermented at 52 to 58 ℃, if the seaweed is chlorellaline, preferably the mixture may be fermented at 52 to 58 ℃ When the seaweed is seaweed, preferably the mixture can be fermented at 22 to 48 ℃, more preferably 32 to 48 ℃, if the seaweed is seaweed, preferably the mixture is 22 to 38 It can be fermented at ℃ or 52 to 58 ℃, more preferably 22 to 38 ℃, if the seaweed is kelp, preferably the mixture is 22 to 58 ℃, more preferably 32 to 38 ℃ or 52 To fermentation at 58 ° C.

As described above, since the seaweeds have different constituents and tissue structures, the optimum reaction temperature, reaction time, and optimum treatment method for producing hydrogen from seaweeds are different for each seaweed.

For example, when the seaweed is blue, the treatment of the seaweed in the step a) is performed by the grinding treatment and heat treatment for 25 to 35 minutes at 100 to 140 ℃ or at 15 to 25 kHz using the grinding and sonic treatment It may be sonicated for 25 to 35 minutes, the fermentation of step c) may be carried out for 40 to 88 hours at the reaction temperature and anaerobic conditions of the mixture of 52 to 58 ℃.

In addition, when the seaweed is chlorellaline, the fermentation of step c) may be carried out for 32 to 88 hours at a reaction temperature of 52 to 58 ℃ and anaerobic conditions.

In addition, when the seaweed is seaweed, the treatment of the seaweed in the step a) may be subjected to the grinding treatment and heat treatment for 25 to 35 minutes at 100 to 140 ℃, the fermentation of step c) is a mixture of 22 to 48 ℃ It can be carried out for 20 to 100 hours at the reaction temperature and anaerobic conditions. As an example, the fermentation of step c) may be performed at 32 to 48 ° C. for 20 to 100 hours, more specifically at 32 to 38 ° C. for 20 to 100 hours or at 42 to 48 ° C. for 50 to 100 hours. It may be carried out, more preferably at 32 to 38 ℃ can be carried out for 20 to 100 hours.

In addition, when the seaweed is seaweed, the fermentation of step c) may be carried out for 32 to 112 hours at the reaction temperature and anaerobic conditions of 22 to 38 ℃ or 52 to 58 ℃. For example, the fermentation of step c) may be performed at 22 to 28 ° C. or 52 to 58 ° C. for 32 to 112 hours, and may be performed at 32 to 38 ° C. for 44 to 100 hours, more preferably 32 At 44 ° C. for 38 hours.

In addition, when the seaweed is kelp, the treatment of the seaweed in step a) may be subjected to the grinding treatment and heat treatment for 25 to 35 minutes at 100 to 140 ℃, the fermentation of step c) is a mixture of 22 to 58 It can be carried out for 8 to 136 hours at the reaction temperature of the ℃ and anaerobic conditions. For example, the fermentation of step c) may be performed at 32 to 58 ° C. for 8 to 136 hours, more specifically at 32 to 38 ° C. for 8 to 88 hours, and at 42 to 48 ° C. for 32 to 124 hours. Or 32 to 136 hours at 52 to 58 ° C, more preferably 8 to 88 hours at 32 to 38 ° C or 32 to 136 hours at 52 to 58 ° C.

As described above, the production efficiency of hydrogen gas, when performing the optimum reaction conditions and processing steps according to the seaweed of the present invention, it is possible to produce hydrogen gas in an environmentally friendly and economical way from the seaweeds, abundant biomass resources .

As described above, the method for producing hydrogen gas from the algae using anaerobic microorganisms according to the present invention is i) economical savings of raw materials because it uses abundant seaweeds due to the characteristics of Korea, which is three sides of the sea, ii) Renewable energy sources such as hydrogen gas can be secured while reducing the amount of waste resources generated by anaerobic digestion of algae, and iii) reducing the amount of carbon dioxide generated through mass culture of algae, Environmental pollution can be prevented, and iv) high concentration culture of seaweed can be used for marine industry development for various purposes, and v) it can increase alternative energy efficiency, such as fuel cell, and has a great economic effect.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are merely to illustrate the invention, the present invention is not limited by the following examples.

< Example >

Example  1: Strain, Substrate and Culture Method

The strain used in the present invention was prepared by centrifuging the activated sludge obtained during the anaerobic sewage treatment process of the Environmental Management Corporation of Busan at 2,000 rpm, 5 min, and 4 ° C., and then receiving the supernatant and preparing the strain. 10 ml of 1% (v / v) per 100 ml of medium was added as cells (Ueno, Y., et al., Journal of Fermentation and Bioengineering, 79 (4), 395-397, 1995). The composition of the medium for culturing the strain is shown in Table 1 below.

In addition, as a substrate (or also referred to as "carbon source") of the strain sucrose (sucrose) or green onion, chlorella (cheongtae), seaweed, seaweed, and kelp mixer (Mini Mixer & cutter, HMF-505, Hanil, Korea), respectively 1 g of 1% (w / v) per 100 ml of culture medium was added. The culture medium and the substrate were sterilized using a sterilizer (HB-506-6, Hanbaek Science, Korea) respectively.

For anaerobic culture, 1% (w / v) of substrate and 1% (v / v) of supernatant received per 100 ml of sterile medium were added to a 300 ml Erlenmeyer flask containing 100 ml of distilled water, followed by nitrogen gas. 10 minutes was injected to remove oxygen in the culture medium, and then sealed and incubated in the microorganism incubator for 12 hours at intervals of 144 hours.

Badge composition Concentration (g / L) NH ₄ HCO ₃ 2 KH ₂ PO ₄ One MgSO ₄ ㆍ 7H ₂ O 0.1 NaCl 0.01 Na ₂ MoO ₄ 2H ₂ O 0.01 CaCl ₂ 2H ₂ O 0.01 MnSO ₄ ㆍ 7H ₂ O 0.015 FeCl ₂ 0.0028

In addition, the hydrogen gas generated during the anaerobic culture was measured using a high-density gas detector (Model No. XP-3140, Cosmos, South Korea).

Example  2: measurement of the production of hydrogen gas from each seaweed according to the culture temperature

In the anaerobic state, in order to investigate the change in the yield of hydrogen gas obtained from each seaweed according to the culture temperature, in one embodiment of the present invention, each seaweed (seaweed, chlorella, seaweed, seaweed, kelp) is pulverized with a mixer at 120 ° C. After heat treatment for 30 minutes, the change in the production of hydrogen gas of each algae cultured for 60 hours at 25 ℃, 35 ℃, 45 ℃, 55 ℃ culture temperature and 200 rpm stirring speed was measured. At this time, sucrose was used instead of the algae as a positive control. The results are shown in Figures 1a-d.

As shown in Figure 1a-d, kelp (4.8 v / v%)> sucrose (2.8 v / v%)> seaweed (2.6 v / v%)> seaweed (2.4 v / v%) at a culture temperature of 25 ℃ > Chlorella (1.8 v / v%)> green (1.5 v / v%), hydrogen production was higher (Fig. 1a), sucrose (21.3 v / v%)> kelp (10.3 v / v) at the incubation temperature of 35 ℃ %)> Seaweed (4.7 v / v%)> green and seaweed (3.1 v / v%)> chlorella (1.4 v / v%), the highest hydrogen production (Fig. 1b), sucrose at 45 ℃ (10.2 v / v%)> Kelp (8.8 v / v%)> Seaweed (4.1 v / v%)> Seaweed (3.5 v / v%)> Chlorella (2.3 v / v%)> Seaweed (1.7 v / v %), The highest hydrogen production (Fig. 1c), and kelp (10.3 v / v%)> green sea (5.4 v / v%)> chlorella (3.6 v / v%)> seaweed (2.9) v / v%)> laver (1.3 v / v%)> sucrose (0.6 v / v%), the highest hydrogen production (Fig. 1d).

From the above results, it was confirmed that the production of hydrogen gas obtained from each cultured algae was slightly different for each seaweed, and showed an increase or decrease in production with the increase of temperature, and the optimum reaction temperature for each seaweed was different. It became.

First, in the case of green, the highest hydrogen production at the reaction temperature of 55 ℃, the highest hydrogen production at the reaction temperature of 55 ℃, Chlorella, the highest hydrogen production at the reaction temperature of 45 ℃ It was high, and in the case of seaweed, hydrogen production was the highest at the reaction temperature of 35 ℃, and for kelp, hydrogen production was confirmed to be the highest at the reaction temperature of 35 ℃ or 55 ℃ (Fig. 1).

Example  3: Determination of the production amount and pH change of hydrogen gas obtained from each seaweed with incubation time

3-1: Change in Production of Hydrogen Gas with Incubation Time

In order to investigate the change in the production amount of hydrogen gas obtained from each seaweed according to the culture time when incubating each seaweed at the culture temperature of Example 2, that is, 25 ℃, 35 ℃, 45 ℃, and 55 ℃, one embodiment of the present invention In the example, the reaction temperature was set to 25 ° C, 35 ° C, 45 ° C, and 55 ° C, and the incubation time was incubated for 144 hours at 12 hour intervals, and then the production of hydrogen gas was measured in the same manner as in Example 2. The results are shown in Figures 2a-d.

As shown in Figure 2a-d, it was confirmed that there is a slight difference for each seaweed.

From the result of Example 2 and the result of FIG. 2A-D,

When the seaweed is blue, 35 ℃ and 55 ℃ was found to be suitable, when the reaction temperature is 35 ℃, the reaction time is suitable for 20 to 64 hours, the reaction temperature is 35 ℃ and 40 to 88 hours is the most suitable Confirmed.

In addition, when the seaweed is chlorella, when the reaction temperature is 25 ℃, the reaction time is suitable for 56 to 100 hours, when the reaction temperature is 35 ℃, the reaction time is suitable for 20 to 76 hours, the reaction temperature is 45 In the case of ℃, the reaction time is suitable 116 to 144 hours, when the reaction temperature is 55 ℃, the reaction time is suitable 32 to 88 hours, the reaction temperature is 55 ℃ and the reaction time is the most suitable 32 to 88 hours It was confirmed.

In addition, when the seaweed is seaweed, when the reaction temperature is 25 ℃, the reaction time is suitable for 44 to 76 hours, when the reaction temperature is 35 ℃, the reaction time is suitable for 20 to 88 hours, the reaction temperature is 45 ℃ When the reaction time is suitable for 56 to 88 hours, the reaction temperature is 55 ℃, the reaction time is suitable 56 to 76 hours, the reaction temperature is 35 ℃ and the reaction time is 20 to 88 hours is the most suitable Confirmed.

Also, when the seaweed is seaweed, when the reaction temperature is 25 ℃, the reaction time is suitable for 44 to 112 hours, when the reaction temperature is 35 ℃, the reaction time is suitable for 32 to 112 hours, the reaction temperature is 45 In the case of ℃, the reaction time is suitable 116 to 144 hours, when the reaction temperature is 55 ℃, the reaction time is suitable 32 to 88 hours, the reaction temperature is reacted 32 to 112 hours at 25 ℃ or 55 ℃, It was confirmed that it is more suitable that the reaction temperature is reacted at 35 ° C. for 44 to 100 hours, the reaction temperature is 35 ° C., and the reaction time is 44 to 100 hours.

In addition, when the seaweed is kelp, when the reaction temperature is 25 ℃, the reaction time is suitable for 44 to 112 hours, when the reaction temperature is 35 ℃, the reaction time is suitable for 8 to 112 hours, the reaction temperature is 45 In the case of ℃, the reaction time is suitable for 32 to 136 hours, when the reaction temperature is 55 ℃, the reaction time is suitable for 20 to 136 hours, the reaction temperature is reacted at 35 ℃ 8 to 88 hours, or the reaction temperature is It was found that the reaction was more suitable for 32 to 136 hours at 55 ° C, the reaction temperature was 55 ° C, and the reaction time was 32 to 64 hours or 80 to 124 hours. In the measurement results, it was confirmed that the kelp is superior to other seaweeds at all reaction temperatures, in particular, the reaction temperature is very excellent at 35 ℃ and 55 ℃.

3-2: according to incubation time pH  change

In addition, in one embodiment of the present invention, the pH change in the culture solution of each seaweed according to the same incubation temperature and incubation time as 3-1 was investigated. pH change was measured using a pH meter (HANNA Instruments, USA). The results are shown in Figures 3a-d.

As shown in Figure 3a-d, there is a slight difference for each algae, but when the algae incubated at the incubation temperature of 25 ℃, 35 ℃, 45 ℃, and 55 ℃ it is found that most of the pH is reduced at 48-60 h Could be (FIGS. 3A-D). This optimizes the generation of hydrogen gas when each seaweed is incubated during the incubation time, thereby producing various volatile organic acids (eg, acetate, propionate, butyrate, etc.) and alcohols such as ethanol to produce pH. Because it lowers.

Example  4: Determination of organic matter content in each seaweed after grinding or after grinding, heat treatment, sonication, acid treatment, and alkali treatment

Substrate reaction conditions for optimizing the organic matter content in the algae are most important in order to maximize production of hydrogen gas from each algae using the optimum incubation temperature and the optimum incubation time identified in Examples 2 and 3. Therefore, in one embodiment of the present invention seaweed, seaweed and kelp in the seaweed of Example 1 used as a substrate of the anaerobic strain was ground, or after heat treatment, sonication, acid treatment, and alkali treatment after grinding, The organic matter content in the algae, ie, chemical oxygen demand (COD), was measured.

The method of measuring the COD value can be divided into a chromium (Cr) method used for a sample without salt or a low COD measurement value, and a manganese (MN) method used for a sample with salinity. In the example, since the salt-containing seaweed was used, the COD value was measured using the manganese method. At this time, the method of culturing the seaweed, seaweed and kelp is the same as in Example 1 except for the incubation time.

As a result of the above experiment, before mixing green seaweed, laver and kelp with the cells prepared in Example 1, the COD measurement values according to various treatment methods (milling, heat treatment, sonication, acid treatment, alkali treatment) are shown in Tables 2 to Table Same as 4:

Blue Processing method Processing conditions COD (mg / L) smash 4920 Crushing + heat treatment 60 ℃, 30 min 5800 Crushing + heat treatment 120 ℃, 30 min 8040 Crushing + sonication 20 W (setting power), 15 min 7640 Crushing + sonication 20 W (setting power), 30 min 8040 Crushing + acid treatment 0.3 N, 30 min 5560 Crushing + acid treatment 1 N, 30 min 4840 Crushing + acid treatment 1.6 N, 30 min 3960 Crushing + alkali treatment 0.3 N, 30 min 5880 Crushing + alkali treatment 1 N, 30 min 5960 Crushing + alkali treatment 1.6 N, 30 min 6440

Kim Processing method Processing conditions COD (mg / L) smash 7920 Crushing + heat treatment 60 ℃, 30 min 3720 Crushing + heat treatment 120 ℃, 30 min 8400 Crushing + sonication 20 W (setting power), 15 min 7920 Crushing + sonication 20 W (setting power), 30 min 8160 Crushing + acid treatment 0.3 N, 30 min 1160 Crushing + acid treatment 1 N, 30 min 1840 Crushing + acid treatment 1.6 N, 30 min 4840 Crushing + alkali treatment 0.3 N, 30 min 5920 Crushing + alkali treatment 1 N, 30 min 4640 Crushing + alkali treatment 1.6 N, 30 min 6160

Kelp Processing method Processing conditions COD (mg / L) smash 3840 Crushing + heat treatment 60 ℃, 30 min 4480 Crushing + heat treatment 120 ℃, 30 min 5360 Crushing + sonication 20 W (setting power), 15 min 4400 Crushing + sonication 20 W (setting power), 30 min 4880 Crushing + acid treatment 0.3 N, 30 min 5520 Crushing + acid treatment 1 N, 30 min 3920 Crushing + acid treatment 1.6 N, 30 min 4720 Crushing + alkali treatment 0.3 N, 30 min 4400 Crushing + alkali treatment 1 N, 30 min 3280 Crushing + alkali treatment 1.6 N, 30 min 4480

(However, acid treatment and alkali treatment are reacted for 30 minutes at each concentration and neutralized to pH 7 to measure COD values.)

As shown in Table 2 to Table 4, the COD value of the seaweed was heat treated at 120 ° C. for 30 minutes (COD: 8040 mg / L) after grinding, and sonication (COD: 8040 mg /) for 30 minutes after grinding in each treatment method. L), 0.3 N acid treatment after grinding (COD: 5560 mg / L), and 1.6 N alkali treatment after grinding (COD: 6440 mg / L) were found to be excellent (Table 2),

The COD value of laver was measured by heat treatment at 120 ° C for 30 minutes (COD: 8040 mg / L), sonication (COD: 8160 mg / L) for 30 minutes after grinding, and 1.6 N acid treatment after grinding (COD). : 4840 mg / L), and 1.6 N alkali treatment (COD: 6160 mg / L) after grinding was found to be excellent (Table 3),

The COD value of kelp is 30 minutes after heat treatment (COD: 5360 mg / L), 30 minutes sonication (COD: 4880 mg / L), 0.3 N acid treatment (COD: 5520 mg /) for 30 minutes after grinding. L), and 1.6 N alkali treatment (COD: 6440 mg / L) after grinding was found to be excellent (Table 4).

In addition, in the case of milling, it was confirmed that the COD values were different according to the seaweed, seaweed and seaweed (seaweed: 4920 mg / L, seaweed: 7920 mg / L, kelp: 3840 mg / L).

Example  5: Determination of the production of hydrogen gas from each seaweed performed under optimized substrate reaction conditions

In order to investigate the production of hydrogen gas obtained from each seaweed performed under substrate reaction conditions optimizing the organic matter content in each seaweed identified in Example 4, in one embodiment of the present invention, the organic matter content from the COD measurement result of Example 4 Each substrate reaction condition that appeared high was selected to measure the yield of hydrogen gas and methane gas. Specifically, seaweed was incubated for 60 hours at 55 ℃, 200 rpm, laver was incubated for 60 hours at 35 ℃, 200 rpm, kelp was incubated for 60 hours at 55 ℃, 200 rpm. The yield of hydrogen gas obtained therefrom is shown in FIGS. 4A-C.

As shown in Figs. 4A-C, in the case of green, ultrasonic treatment for 30 minutes after grinding (hydrogen production: 3.1 v / v%)> heat treatment at 120 ° C. for 30 minutes after grinding (hydrogen production: 3 v / v%)> After grinding, the production of hydrogen gas was higher in order of 0.3 N acid treatment (hydrogen production: 1.2 v / v%) (FIG. 4A); For laver, heat treatment at 120 ° C for 30 minutes (hydrogen production: 7.7 v / v%)> grinding (hydrogen production: 3.3 v / v%)> sonication 30 minutes after grinding (hydrogen production: 2.4 v / v%) > Yield of hydrogen gas was higher in order of 1.6 N acid treatment (hydrogen yield: 1.5 v / v%) after grinding (FIG. 4B); And kelp heat treatment at 120 ° C. for 30 minutes (hydrogen production: 11.9 v / v%)> grinding (hydrogen production: 9.7 v / v%)> sonication for 30 minutes after grinding (hydrogen production: 8.9 v / v% )> After the grinding, 0.3 N acid treatment (hydrogen yield: 7.7 v / v%) was confirmed that high hydrogen gas yield was shown in the order (FIG. 4C).

In addition, in one embodiment of the present invention was measured the production amount of hydrogen gas according to the substrate concentration of each seaweed, the results are shown in Figure 5a-e.

As shown in Figures 5a-c, the substrates were increased to 1% (v / v), 3% (v / v) and 5% (v / v) at the optimum culture conditions of green, seaweed, and kelp, respectively. As a result of measuring the production of hydrogen gas, the production of hydrogen gas was the best when the substrate concentration was 3% (v / v) in the case of blue (Fig. 5a); And the case of laver and kelp was confirmed that the highest production of hydrogen gas when the substrate concentration is 5% (v / v) (Figs. 5b and 5c).

In addition, the production of hydrogen gas according to the substrate concentration was also measured for chlorella and wakame seaweed. The optimum culture condition of chlorella is 60 hours at 45 ℃, 200 rpm, the wakame for 60 hours at 35 ℃, 200 rpm It is to culture. The results are shown in Figures 5d and 5e.

As shown in FIGS. 5D and 5E, when the green seaweed was used as a substrate, it was treated for 30 minutes at 120 ° C. after pulverization, or in the case of chlorella and wakame, the yield of hydrogen gas was best when the substrate concentration was 5% (v / v). It was confirmed excellent (FIGS. 5D and 5E).

In addition, in one embodiment of the present invention in order to investigate the relationship between the anaerobic state in the culture medium and the production of hydrogen gas obtained from fermented algae, the nitrogen gas is 0, 10, 20, 30, 40, After 50, and 60 minutes of injecting, respectively, the production of hydrogen gas obtained from the kelp was measured by culturing at optimum culture conditions (55 ° C., 60 hours at 200 rpm). The results are shown in FIG.

As shown in FIG. 6, when nitrogen gas was injected for 20 minutes, it was confirmed that the yield of hydrogen gas was the best, and when it exceeded 20 minutes, the yield of hydrogen gas was not increased (FIG. 6). . This means that when the nitrogen gas is injected for about 20 minutes, the anaerobic state in the culture is almost achieved.

Figure 1a-d is a graph showing the hydrogen gas production from each seaweed according to the culture temperature according to an embodiment of the present invention, Figure 1a is 25 ℃, Figure 1b is 35 ℃, Figure 1c is 45 ℃ and Figure 1d Each was measured at a culture temperature of 55 ° C.

Figure 2a-d is a graph showing the hydrogen gas production from each seaweed according to the incubation time (0 ~ 144 hours, 12 hours interval) according to an embodiment of the present invention, Figure 2a is 25 ℃, Figure 2b is 35 ℃ 2C are measured at 45 ° C. and FIG. 2D at 55 ° C. incubation temperature.

Figure 3a-d is a graph showing the pH change in each seaweed according to the incubation time (0 ~ 144 hours, 12 hours interval) according to an embodiment of the present invention, Figure 3a is 25 ℃, Figure 3b is 35 ℃, Figure 3c is measured at 45 ° C. and FIG. 3d is a culture temperature of 55 ° C., respectively.

Figure 4a-c is a graph showing the production of hydrogen gas obtained from each seaweed according to various substrate treatment conditions according to an embodiment of the present invention, Figure 5a is blue, Figure 5b is laver and Figure 5c is measured using kelp It is.

Figure 5a-e is a graph showing the yield of hydrogen gas obtained from each seaweed according to the treatment concentration of various substrates according to an embodiment of the present invention, Figure 5a is green, Figure 5b is laver, Figure 5c is kelp, Figure 5d Is chlorella and Figure 5e is measured using seaweed.

6 is a graph showing the amount of hydrogen gas produced from kelp according to the injection time of nitrogen gas according to an embodiment of the present invention.

Claims (8)

a) treating the algae; b) preparing a mixture by mixing the seaweed and the anaerobic microorganism or the reaction solution containing the anaerobic microorganism performing step a); And c) fermenting the mixture at 20 to 60 ° C. and anaerobic conditions, Treatment of the seaweed of step a) is a grinding treatment; Heat treatment under conditions of 100 to 140 ° C; Sonication at 15-25 kHz conditions; Acid treatment with 0.1-1.8 N acid; And alkali treatment with 0.1 to 1.8 N alkali. Hydrogen gas production method. The method of claim 1, Heat treatment of the seaweed of step a) is heat treatment for 15 to 45 minutes at 100 to 140 ℃, the ultrasonic treatment is sonication for 25 to 35 minutes at 15 to 25 kHz using a sonic processor, the acid The treatment is an acid treatment to react using 0.1 to 1.8 N acid, and the alkali treatment is an alkali treatment to react using 0.1 to 1.8 N alkali. Hydrogen gas production method. The method according to claim 1 or 2, The algae of step a) is green and the temperature of step c) is 52 to 58 ° C; The algae of step a) is chlorella, and the temperature of step c) is 52 to 58 ° C; The algae of step a) is laver and the temperature of step c) is 22 to 48 ° C; The seaweed of step a) is seaweed, and the temperature of step c) is 22 to 38 ° C or 52 to 58 ° C; Seaweed of step a) is kelp, the temperature of step c) is characterized in that 22 to 58 ℃ Hydrogen gas production method. The method of claim 3, The algae of step a) is a seaweed, the treatment of the seaweed is 25 to 35 minutes at 15 to 25 kHz using a pulverization treatment and sonication treatment or grinding treatment and heat treatment for 25 to 35 minutes at 100 to 140 ℃ To sonicate, and the fermentation of step c) is performed for 40 to 88 hours. Hydrogen gas production method. The method of claim 3, The algae of step a) is chlorella, fermentation of step c) is performed for 32 to 88 hours, Hydrogen gas production method. The method of claim 3, The seaweed of step a) is seaweed, and the treatment of seaweed is ground treatment and heat treatment for 25 to 35 minutes at 100 to 140 ℃, the fermentation of step c) is carried out for 20 to 100 hours, Hydrogen gas production method. The method of claim 3, Seaweed of step a) is seaweed, fermentation of step c) is carried out for 44 to 100 hours, Hydrogen gas production method. The method of claim 3, The seaweed of step a) is kelp, the treatment of the kelp is grinding and heat treatment for 25 to 35 minutes at 100 to 140 ℃ and the fermentation of step c) is carried out for 8 to 136 hours, Hydrogen gas production method.

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