JP2013036016A - Method for separating volatile fuel oil contained in algae by solar heat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate organic compounds, contained in algae and capable of being used as fuel oil, from the algae at low cost.SOLUTION: Volatile components such as hydrocarbons are separated from algae by repeating, at least once, the operation comprising: filling the inside of a pressure container, whose surface is covered with a solar heat absorbing film, with water and algae and closing the container; then heating the water and algae under a high temperature environment of 50-300°C formed by the irradiation with solar light; reducing the pressure in the pressure container down to normal pressure as rapidly as possible when the pressure is raised by generated water vapor up to a predetermined pressure in the range of 1.4 to 5.0 atmospheres; and applying heat and the pressure and reducing the pressure, again.

Description

  The present invention relates to separation of volatile fuel oil contained in algae.

Hydrocarbons, carbohydrates and other organic substances contained in algae are known to contain useful substances used in fuels, industrial chemicals, cosmetics or pharmaceuticals. Methods such as cell membrane disruption, ultrasonic vibration, compression and pressure, contact cracking, solvent extraction, supercritical solution extraction, or distillation have been practiced. However, the situation that has not been realized as an industry has continued for the economic reason that the energy required for the separation and extraction is larger than the energy obtained as fuel, particularly in hydrocarbons and carbohydrates intended for fuel. For this reason, only those used for pharmaceuticals and cosmetics with high added value other than fuel have been commercialized, but fuel oil has been in a trial-and-error situation in search of economic efficiency.
However, as the population on the earth grows, there is an urgent need to solve the problem due to the environmental problem of global warming caused by carbon dioxide and the problem of exhaustion of fossil fuels.
In connection with the technical field of the present invention, numerous patents have been filed in the past. Typical examples are given below. Patent Document 1 is an example in which ethanol is collected by breaking a cell membrane of algae by a mechanical method. Patent document 2 is an example of mechanical cell membrane destruction by a rotary blade. After this, it is considered that organic substances such as fuel are collected by distillation or the like. In Patent Document 3, a cell membrane is destroyed from an algae containing 5 to 96% of water by a mechanical method, an enzyme treatment, an alkali treatment, or the like, followed by an extraction step with supercritical carbon dioxide, alcohol or other solvent, and then a fuel or the like. This is an example of collecting organic matter. Patent document 4 is an example which extracts a hydrocarbon using a solvent through a contact cracking process. In Patent Document 5, when a useful substance is collected from a plant seed or the like, pressurization and decompression are performed at room temperature using a pressure vessel and a pump from the outside. In particular, when making tofu from soybeans, it is described that tofu without nests can be made by this pressurization and decompression operation.
Non-Patent Documents 1 and 2 are articles on the technology of collecting fuel from algae by Takaaki Maekawa (Professor Emeritus, University of Tsukuba, Director of Tsukuba Biotech Research Institute) and Shin Watanabe (Professor, University of Tsukuba). Non-Patent Document 3 describes the company's technology for extracting fuel oil from algae of OriginOil, USA, and is currently said to be the most efficient extraction technology in the world. The company announced in 2011 that it succeeded in extracting the world's first profitable algae. The core of this technology is the application of ultrasonic vibration to algae to cause destruction of algal cell membranes. However, destruction of cell membranes is not sufficient with ultrasonic vibration alone, and further improvements are desired. The details are unknown, but it has announced that it is also injecting carbon dioxide. Non-Patent Document 4 is a report which investigated and examined the possibility of a business to culture and extract valuable materials such as EPA and fuel oil from microalgae from the technical and economic aspects. We are investigating in detail, including the situation in other countries, the problems of vast culture sites, water procurement problems, technical problems related to algae culture and extraction of valuable resources. EPA and other high-value-added products are profitable, but it is the view that fuel oil needs to be examined for further cost reduction.

JP 7-87983 A JP 2010-162499 A JP 2011-68741 A Patent publication 2010-539300 JP 2005-87183 A

Takaaki Maekawa Tsukuba Biotech Research Institute Homepage http: // maekawabio. org / aurantio. pdf Shin Watanabe (Algae Biomass Energy Technology Perspective) http: // www. sakura. cc. tsukuba. ac. jp / ~ efforum / 1st3EF / 1st3EFwatanabe. pdf OriginOil (USA) home page: http: // www. originoil. com / technology / overview. html 2011 Ministry of Agriculture, Forestry and Fisheries Green and Water Environmental Technology Revolution Project Project “Survey Report on Establishment of Microalgae Culture Technology in Abandoned Cultivation Area and Examination of Commercialization Strategy” April 2011 Co-authored by two other companies www. j-phoenix. com / pages / 65 / file201110625. pdf

    The problem was to separate fuel oil from algae at low cost.

In the algae tissue, volatile organic compounds such as hydrocarbons could not be economically separated and collected due to the large consumption of energy required for cell membrane destruction of algae.
The present invention heats a pressure vessel containing algae containing moisture in a high-temperature environment created by irradiating solar rays, and abruptly Therefore, the basic means is to separate the volatile organic compound from the algal tissue by utilizing the difference in specific gravity with water by destroying the binding of algal cell membrane tissue and applying a reduced pressure operation.

Specifically, (1) installed in a high temperature environment of 50 to 300 ° C. created by irradiating with solar rays (1-1) “metal coated with a surface by a solar ripening absorption film” After introducing algae prepared with water so as to be submerged in a volume range of 30 to 90% of the pressure vessel (hereinafter abbreviated as “pressure vessel”) (1-2) Pressure The container is sealed and heated, and when the pressure in the pressure container raised by the generated water vapor reaches a predetermined pressure of 1.4 to 5.0 atm, the pressure is reduced to normal pressure as soon as possible. (1-3) Next, discharge the algae from the pressure vessel into the aquarium and adjust the amount of water in the aquarium so that the algae are submerged in the aquarium. And then left to stand, "both organic compounds such as hydrocarbons, boiling point Atmospheric pressure at 300 ° C. or less of the volatile component "(hereinafter referred to as volatile components) in the water surface of the upper, the method of separating the residue of algae water bottom.

(2) An on-off valve or an on-off valve for introducing the alga prepared with water so that the pressure vessel is submerged in the volume range of (2-1) 30 to 90% of the pressure vessel. (2-2) Open / close valve or open / close valve for discharging the algae out of the pressure vessel after repeating the pressurization and depressurization operations on the algae one or more times with water vapor generated by heating. (2-3) Opening part equipped with a pressure regulating valve for reducing the pressure in the pressure vessel to normal pressure and restoring the pressure again The above three types of opening parts are provided. 2. A method for separating the volatile component according to 1 above, which is a heat treatment apparatus characterized by the above, to the upper part of the water surface and the algae residue to the bottom of the water.

(3) The pressure vessel has a volume range of 30-90% in the pressure vessel when (3-1) the opening and the opening fitted with the pressure regulating valve are closed and the inlet is open. (3-2) The volume of the algae prepared with water is within the volume range of 30 to 90% of the pressure vessel. (3) Water vapor generated by heating in a high temperature environment of 50 to 300 ° C. created by irradiating sunlight. When the pressure in the pressure vessel reaches a predetermined pressure between 1.4 and 5.0 atm, the pressure adjustment valve is opened as soon as possible to reduce the pressure in the pressure vessel to normal pressure. Repeat heating and depressurization operations that impact algae at least once. The volatile components the water surface of the upper portion according to the paragraph (1), symptom, method for separating the residue of algae water bottom.

(4) The solar heat absorption film coated on the surface of the pressure vessel is selected from (4-1) carbon black, graphite, copper oxide, manganese dioxide, cobalt oxide, chromium oxide, iron oxide, lead sulfide or nickel sulfide. (4-2) These substances are formed by physical surface coating treatment such as vapor deposition, sputtering or CVD, and chemical surface coating treatment such as plating or oxidation treatment. Alternatively, the volatile component according to item 1 is applied to the upper part of the water surface, and algae residue is applied to the surface by applying a coating prepared by kneading with a synthetic resin binder and drying and coating the surface. Separating to the bottom of the water.

  (5) The pressure vessel is made of stainless steel, aluminum alloy, titanium, titanium alloy, copper, or copper alloy. Separating to the bottom of the water.

  (6), the synthetic resin binder described in (4-2) is selected from acrylic resin, vinyl resin, polyester resin, silicone resin, urethane resin, epoxy resin, phenol resin, polyimide resin, and synthetic rubber, alone or 2. A method for separating a volatile component according to item 1 above at the top of the water surface and algae residue at the bottom of the water, which is a mixture of two or more.

  (7) The repeated operation of heating and depressurization described in (3-3) above, which opens the pressure regulating valve as quickly as possible to depressurize the pressure in the pressure vessel to normal pressure and gives an impact on the algae. When performed once or more, water vapor containing volatile components ejected from the opening of the pressure regulating valve to the outside of the pressure vessel passes through an air-cooled or water-cooled condensing tube to form liquid, and this liquid is condensed into the condensing tube. A method of separating volatile components floating on the water surface by capturing them in a container provided at the outlet of the water and leaving them standing.

  The above items 1, 2, 3, 4, 5, 6 and 7 are the means of the present invention. The following is a supplementary explanation.

The high temperature environment is created by irradiating sunlight with a sunlight reflector or a condenser lens, and has already been put into practical use for power generation using this principle. In the present invention, a solar reflector is mainly used. The high temperature environment by irradiation with sunlight includes a lateral trough type and a vertical tower type, and the present invention includes algae containing water in the high temperature environment. A pressure vessel is introduced and heated. In the present invention, the horizontal trough heat treatment apparatus shown in FIG. 1 and the vertical tower heat treatment apparatus shown in FIG. 2 can be used. It is excellent in management and preferable. The algae culture apparatus which is the pre-process of the present invention and the pressure vessel heated by solar heat which constitutes the main part of the present invention are continuously installed. In order to adjust the moisture contained in the algae, a mesh portion is provided at the end of the culture apparatus close to the connecting portion, and the moisture is filtered and adjusted. The amount of water is such that the algae are submerged in the pressure vessel. This range is preferable because the impact effect of pressurization and decompression on algae is great.
The temperature near the surface of the pressure vessel is preferably 50 to 300 ° C., and the temperature for heating the algae inside the pressure vessel is preferably 110 to 150 ° C. When the temperature exceeds 300 ° C., carbonization of algae begins and volatile components may be oxidized. In that case, it is not preferable because it is performed under nitrogen gas filling and the system becomes complicated. The algae residue after separation of volatile components is used as a recovery of water-soluble valuables, livestock feed or fertilizer.
The pressure range in the pressure vessel is 1.4 to 5.0 atm (the temperature in the pressure vessel is about 110 to 150 ° C.), and when the pressure reaches a predetermined pressure, the pressure inside the pressure vessel is reduced to algae. Impact is applied to break the cell membrane and separate volatile components. This pressurizing operation and depressurizing operation are repeated once or more, preferably about 3 to 5 times. As a result, the cell membrane of the algae is almost completely destroyed, and almost 100% of the volatile components can be separated. This depressurization operation is performed when the pressure reaches the pressure determined by examining the size of the pressure vessel and the type of algae in advance. The time interval from depressurization to repressurization is also determined in advance with respect to the size of the pressure vessel and the type of algae.

  The present invention is applicable to photosynthetic algae such as Botriococcus, Euglena, Blue-green, Pseudocollistis or Isotilis galvana and Nannocloprosis, and heterotrophic algae such as Aurantiochytrium. Algae grow only algae having a dry weight of about 1% with respect to the water of the medium, and algae containing 20 to 70% of the weight of the dry algae as fuel oil such as hydrocarbons are preferred as the object of the present invention. This algae is in a wet algae state that is submerged in the pressure vessel in the vicinity of the outlet from the medium, that is, in front of the pressure vessel, and is then introduced into the pressure vessel and heated and heated. Pressurize and depressurize to relax and break cell membrane binding. During this operation, when an opening equipped with a pressure regulating valve is opened and a pressure reducing operation is performed, water vapor containing a volatile component is ejected from the opening. The water vapor is cooled in a condenser tube and collected as a liquid, and volatile components can be separated from the liquid. When the pressurization and decompression operations are repeated 3 to 5 times, the volatile components are almost discharged from the pressure vessel. At this time, since the amount of water in the pressure vessel also decreases, water is supplied to such an extent that the algae are submerged.

  In the process of the present invention, it is possible to use a known algae cell membrane disruption method in addition to the application of ultrasonic vibration and supercritical extraction, which have been used conventionally. However, these combined use also constitutes the basic fundamental technology of the present invention, and is included in the present invention and does not deny the present invention.

  The method for separating volatile components from algae according to the present invention is performed in a high temperature environment created by irradiation with sunlight. For this reason, volatile components can be collected from algae with low-cost energy without using fossil fuel or electric power. Algae cell membrane destruction can be performed by a simple valve operation in order to take advantage of the shock caused by the release of water vapor pressure, which enables almost complete cell membrane destruction. By these things, the cost reduction of the subject was realizable.

  Explanatory drawing of the trough type | system | group which isolate | separates volatile fuel oil and algae in the high temperature environment produced by irradiating sunlight.   Explanatory drawing of the tower type system which isolate | separates volatile fuel oil and algae in the high temperature environment produced by irradiating with a solar ray.

  The present invention relates to a step of culturing algae containing volatile components and then separating them. In the culturing process, in the case of photosynthetic algae, algae are grown by irradiating light while increasing the concentration of carbon dioxide in the aqueous medium. In heterotrophic algae, algae grow using organic substances in water medium as nutrients. These media tend to be acidic and require that the water be kept alkaline by some operation. This method is generally performed with a buffer solution. For this purpose, it is necessary to control the concentration of salt such as sodium. One of the present inventors previously proposed a method using a polarizable positive electrode (Japanese Patent Application No. 2010-291056) to increase the negative charge density of the culture water and make it alkaline. By doing so, we succeeded in creating a stable algae growth environment in a medium environment with a low salt concentration such as sodium. The present invention relates to a process for separating volatile fuel oil from cultured algae. However, when the negative charge density is increased, the present invention shows alkalinity, and the pH value range is 7.1 in the results of the present invention. ˜13.0. In actual work, it was confirmed that the separation of volatile components was carried smoothly by adjusting preferably to the range of 7.1 to 10.0. In the case of algal varieties and large-scale industrial production, the pH value is adjusted to an appropriate pH range suitable for each condition. For example, in the case of heterotrophic orchitotoquinolium, the separation of fuel oil proceeded relatively smoothly at a slightly low pH of 7.1 to 7.5. The adjustment of the pH and the wet algal state is performed during the culturing which is the previous step, and then proceeds to the separation step of the present invention.

After culturing, the algae contain water that is submerged when introduced into the pressure vessel and is introduced into a high temperature environment created by irradiating sunlight. As an introduction method, a tower type having a circular cross-section and a vertical pressure vessel is preferable because it can be easily obtained by dropping algae containing water from the upper opening by gravity. The material is preferably made of copper or copper alloy having excellent heat conduction. The pressure vessel is irradiated with sunlight rays from the circumferential direction by a curved or flat reflecting plate to obtain a high temperature environment. Algae tend to float on the water surface in the early stage of heating, and are separated by sinking to the bottom of the water leaving a volatile component on the water surface with heating, pressurizing and depressurizing operations. If the temperature is 150 ° C. or lower, the light receiving surface is preferably a solar heat absorbing film that has been treated with black copper oxide or chrome oxide. In the blackening treatment, a chemical surface treatment for oxidizing and blackening copper is simpler and easier to maintain than a physical surface treatment such as sputtering. When using a coating film, it is preferable to use a thermosetting resin such as an epoxy resin, a silicone resin, or a polyimide resin as a binder, and to use black copper oxide as a material of the absorption film.
The pressure in the pressure vessel exposed to a high temperature environment by irradiation with sunlight is preferably 1.4 atm or more, and the temperature at that time is in the range of 110 to 150 ° C. and the maximum pressure is 5.0 atm or less. preferable. In the decompression operation performed at 1.4 atmospheres or more, it is important to open the pressure regulating valve in as short a time as possible to reduce the pressure and to give an impact to the algae to cause cell membrane destruction. Then, after 30 seconds to about 1 minute, the pressure reducing valve is closed and reheating and repressurization are started. Volatile fuel oil collected on the upper surface of the water is collected by first discharging the algae residue at the bottom of the water from the outlet of the pressure vessel and then discharging it to the outside. The number of decompression shocks is about 3 to 5 times as a standard. By this operation, fuel oil can be collected more than 95% and almost 100%.
The time from when the algae containing water is heated in the pressure vessel until the collection of the volatile components is completed, it is possible to enter the next cycle within 0.5 to 1 hour of one cycle. Effective sunshine hours, about 6 hours, and about 10 cycles are possible, and an efficient system scale is designed in accordance with the speed of the algal culture process. Since solar heat can be stored using a salt bath, it can be used as an auxiliary, and solar heat is indirectly transmitted into the pressure vessel. This technology has already been used for power generation and is almost established.

When the pressure regulating valve is opened, the pressure in the pressure vessel is released and water vapor containing a volatile component is ejected from the opening. The ejected matter is not released into the atmosphere, but is collected in a container provided at the outlet of the condensing tube after being liquefied by water cooling or air cooling in the condensing tube. When the recovered liquid is left standing, a volatile component floats above the water surface and is separated.
The algal residue from which the volatile components have been separated is finally collected in a residue collecting section provided at the bottom of the pressure vessel and discharged to the outside.
The above is the standard form for separating fuel oil from algae.

DESCRIPTION OF SYMBOLS 1 Pressure regulating valve 2 Entrance part where water-containing algae are introduced 3 Entrance side opening / closing valve or opening / closing lid 4 Outlet for sending jetting vapor to condensing pipe 5 Top surface of submerged algae in pressure vessel 6 Pressure vessel 7 Pressure Regulating valve 8 Solar heat absorbing film 9 Algae containing water filled in the can 10-1 Drainage side opening / closing valve or opening / closing lid 10-2 Drawer side opening / closing valve or opening / closing lid Also serving as algae outlet after heating and pressurizing treatment 11 Heat-pressurized and pressure-reduced alga discharge port side open / close valve or open / close lid 12 Reflected solar radiation plate 13 Exhaust port for sending ejected vapor to condenser tube

Claims (7)

(1) “Metal pressure vessel surface-coated with a solar heat absorbing film” (hereinafter abbreviated as “pressure vessel”) installed in a high temperature environment of 50 to 300 ° C. created by irradiating with sunlight. ) After introducing algae prepared by mixing water so that it is submerged within the volume range of 30 to 90% of this pressure vessel, (2) The pressure vessel is sealed and heated, and rises by the generated water vapor When the pressure in the pressure vessel reaches a predetermined pressure of 1.4 to 5.0 atmospheres, repeat the heating and depressurization operations to reduce the pressure to normal pressure as quickly as possible and to give an impact to the algae. (3) Next, discharge the algae from the pressure vessel into the aquarium, adjust the amount of water in the aquarium so that the algae are submerged in the aquarium, and then leave it to stand. A volatile component with a boiling point of 300 ° C or less at normal pressure. (Hereinafter volatiles abbreviated) to the water surface of the upper, the method of separating the residue of algae water bottom. The pressure vessel is (1) an inlet portion equipped with an opening / closing valve or an opening / closing lid for introducing the algae prepared with water so as to be submerged in a volume range of 30 to 90% of the pressure vessel. (2) An outlet portion equipped with an opening / closing valve or an opening / closing lid for discharging the algae to the outside of the pressure vessel after repeatedly performing pressurization and decompression operations on the algae one or more times with steam generated by heating. 3) An opening equipped with a pressure regulating valve for reducing the pressure in the pressure vessel to normal pressure and restoring the pressure again. The heat treatment apparatus is characterized by having the above three types of openings. A method for separating a volatile component according to claim 1 at the top of the water surface and algae residue at the bottom of the water. The pressure vessel is (1) closed at the outlet and the opening to which the pressure regulating valve is attached, and when the inlet is open, the pressure vessel is submerged in a volume range of 30 to 90% of the pressure vessel. (2) When the volume of the algae prepared with water is 30-90% of the pressure vessel, the opening / closing valve or opening / closing of the inlet is performed. The lid is closed and heated in a high temperature environment of 50 to 300 ° C. created by irradiating with sunlight. (3) The pressure in the pressure vessel is 1.4 to 5 by the steam generated by the heating. When a predetermined pressure of 0.0 atm is reached, the pressure regulating valve is opened as soon as possible to reduce the pressure in the pressure vessel to normal pressure and repeatedly perform heating and depressurization operations that impact the algae. It is performed once or more, The claim 1 characterized by the above-mentioned The nonvolatile component in the water surface of the upper, the method of separating the residue of algae water bottom. The solar heat absorbing film coated on the surface of the pressure vessel is (1) a simple substance or a composite selected from carbon black, graphite, copper oxide, manganese dioxide, cobalt oxide, chromium oxide, iron oxide, lead sulfide or nickel sulfide. (2) These materials are kneaded with a physical surface coating treatment such as vapor deposition, sputtering or CVD, a chemical surface coating treatment such as plating or oxidation treatment, or a synthetic resin binder. 2. The method of separating a volatile component at the top of the water surface and algae residue at the bottom of the water according to claim 1, wherein the coating material is applied and dried to apply a surface coating treatment.   The volatile component according to claim 1, wherein the pressure vessel is made of stainless steel, aluminum alloy, titanium, titanium alloy, copper, or copper alloy, and the algal residue is separated into the bottom of the water. how to.   The synthetic resin binder described in (2) of Claim 4 is single or two types selected from acrylic resin, vinyl resin, polyester resin, silicone resin, urethane resin, epoxy resin, phenol resin, polyimide resin and synthetic rubber The method according to claim 1, wherein the volatile component is separated into the upper part of the water surface and the algal residue is separated into the bottom of the water.   One or more repetitions of heating and depressurization operations that open the pressure regulating valve as quickly as possible and depressurize the pressure in the pressure vessel to normal pressure and give impact to algae as described in (3) of claim 3 Water vapor containing volatile components that are blown out of the pressure vessel from the opening where the pressure regulating valve is opened is made liquid by passing it through an air-cooled or water-cooled condenser tube, and this liquid is provided at the outlet of the condenser tube. A method of separating volatile components that have been trapped in a container and allowed to stand and floated on the surface of the water.

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