JP2009106258A - Method for producing ethanol - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ethanol production method improving the recovery rate of thermal energy in waste food and facilitating the treatment of a solid component constituted of the residue generated in the treatment. <P>SOLUTION: Ethanol is produced by saccharifying, fermenting and distilling a waste food by using a three-phase centrifugal separator to separate into three phases including an oil component, a saccharified liquid component and a solid component in either one of solid-liquid separation processes for the saccharified liquid, the fermented liquid or the distillation waste liquid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing ethanol by saccharification, fermentation, and distillation of food waste.

  Specifically, the present invention relates to a method for producing ethanol from garbage.

  Food waste such as food waste contains carbohydrates such as rice, bread and noodles, hexasaccharides, pentoses, etc., and a recycling system for producing ethanol, which is a liquid fuel, is fermented with ethanol. It is known that it can be done.

  The method collects organic waste containing a sugar source such as starch, saccharifies it into monosaccharide, adds ethanol-fermenting yeast, and after all the sugar is consumed within a few hours to several months, ethanol is used. The fermentation broth is distilled to separate and purify ethanol. In order to make the ethanol purity 99% or more, an azeotropic or anhydrous film is used.

  Various proposals have been made for methods for producing ethanol from food waste.

  For example, Japanese Patent Laid-Open No. 2007-111590 (Patent Document 1) discloses a step of pulverizing raw garbage to generate a pulverized product, and adjusting the starch concentration of the pulverized product to add saccharifying enzyme to generate saccharified water. A step of inoculating Zymomonas mobilis inoculated in pre-cultured saccharified water for alcohol fermentation to produce moromi, and recovering ethanol by distilling the moromi. Glucose conversion rate exceeding 45% is obtained, ethanol can be efficiently produced from raw garbage, and by contributing to ethanol production for gasoline addition in Japan, there is a method that can recover ethanol with high efficiency from raw garbage. Are listed.

  JP-A-2005-65695 (Patent Document 2 below) discloses a method for producing ethanol by fermentation using a raw material containing starch, and a pellet forming step for forming pellets from the raw material; A saccharification step for inoculating koji mold to obtain a saccharified pellet, and solid fermentation for solid fermentation by adjusting the water content at the start of fermentation of the fermentation mash composed of the saccharified pellet, yeast and water to 30 to 60% by weight And a method for producing ethanol and a system for producing ethanol that do not discharge waste liquid in the process of producing alcohol are described.

  Japanese Patent Laid-Open No. 2006-325577 (Patent Document 3 below) includes an alcohol production section and a waste liquid treatment / use section, and includes an alcohol production section, a saccharification section, a concentration section, a first fermentation section, a distillation section, and a dehydration section. And producing alcohol (fuel alcohol) from biomass raw material (garbage). In the saccharification part, lactic acid is produced by microorganisms that live in the garbage, and the pH of the saccharified solution is lowered. In the concentration section, the total sugar concentration of the concentrated saccharified solution is concentrated in the range of 100 g / l or more and 300 g / l or less, and the pH of the concentrated saccharified solution is close to 4.0 due to the concentration of lactic acid, thereby making the garbage effective A system that can be used to produce alcohol efficiently without the need for sterilization, pH adjustment, and addition of nutrients to the yeast even when using yeast belonging to Saccharomyces cerevisiae used in liquor production Is described.

  However, in the conventional ethanol production methods described in Patent Documents 1 to 3, the piping may be clogged with oil contained in the saccharified solution, and the heat recovery rate of starch contained in raw garbage is reduced. There was a problem.

Further, in conventional ethanol recycling, sugars in organic waste are used as ethanol raw materials, so that all substances other than sugars are discharged as residues.
JP 2007-111590 A JP 2006-325577 A JP 2006-325577 A

  The present invention solves the problems of the prior art as described above, improves the recovery rate of thermal energy contained in food waste, and easily treats solids that are residues generated during processing It is an object to provide a manufacturing method.

In the solid-liquid separation process of any one of the saccharified solution, the fermented solution, and the distillation waste solution, the present invention, as a result of intensive studies in order to solve the above-described problems, has an oil content, a saccharified solution content, and a solid content of 3 An ethanol production method that improves the recovery rate of thermal energy contained in food waste by using a three-phase centrifuge that separates into phases, and that can easily handle solids that are residues generated during processing It is provided and the gist thereof is the following contents as described in the claims.
(1) A method for producing ethanol by saccharifying, fermenting, and distilling food waste, wherein in the solid-liquid separation step of any one of the saccharified liquid, the fermented liquid, and the distilled waste liquid, the oil component, the saccharified liquid A method for producing ethanol, characterized by using a three-phase centrifuge that separates into three phases of solids and solids.
(2) The method for producing ethanol according to (1), wherein solids not separated in the solid-liquid separation step are removed using a screen having a mesh of 0.1 mm to 10 mm.
(3) In the previous stage of the solid-liquid separation step, separating contaminants such as plastic, paper, bags, disposable chopsticks, metal, crustaceans using a filter-type squeezing machine, vibrating sieve device, punching metal and net The ethanol production method according to (1) or (2), which is characterized.
(4) When the concentration of the saccharified solution containing a plurality of types of sugar, salt and SS (suspended solids) is measured using a Brix meter (refractometer) and the concentration exceeds a specified value The ethanol production method according to any one of (1) to (3), wherein the ethanol is discharged.
(5) The residue separated as a solid content in the solid-liquid separation step is treated with a waste treatment facility that incinerates or melts waste, and the extracted steam generated when generating power using waste heat generated at that time The method for producing ethanol according to any one of (1) to (4), wherein the method is used for a concentration step and a distillation step of the food waste.
(6) The oil obtained by separating in the three-phase centrifugal separator is used as a regenerated oil fuel after being treated by either or both of oil / water separation and filtration. The ethanol production method according to any one of (5).
(7) Recycled oil fuel is used as fuel for waste treatment equipment that incinerates or melts adjacent waste, and fossil fuel used in the waste treatment equipment is reduced or incinerated and generated by combustion (6) The method for producing ethanol according to (6), wherein the extracted steam when generating electricity using waste heat is used for the concentration step and distillation step of the food waste.
(8) The oil obtained by separation in the three-phase centrifugal separator is used as a raw material for biodiesel fuel containing fatty acid methyl ester by transesterification, subcritical treatment, etc. (1) The ethanol manufacturing method as described in any one of thru | or (6).
<Action>
According to the invention of (1), food waste generally contains several percent of oil, which causes piping blockage and fermentation inhibition, but can be avoided. In addition, by performing the centrifugation step immediately after saccharification / fermentation at 28 ° C. or higher and immediately after distillation at 40 ° C. or higher, the fluidity of the oil is increased and separation and recovery are facilitated. The recovered oil can be used as fuel for an adjacent incinerator.
According to the invention of (2), since solids that have not been separated in the liquid separation step are removed using a screen having a mesh of 0.1 mm to 10 mm, operation inhibition factors such as concentration, fermentation, and distillation steps in the subsequent steps Don't be.
According to the invention of (3), in the first stage of the solid-liquid separation process, using a filter-type squeezing machine, a vibration sieving device, a punching metal and a net, impurities such as plastic, paper, bag, disposable chopsticks, metal, shellfish, etc. Therefore, it is possible to separate impurities that cannot be completely removed by a crushing and sorting machine.
According to the invention of (4), since the concentrated concentration of the saccharified solution containing a plurality of types of sugar, salt, SS (suspended solids), etc. is managed using a Brix meter (refractometer), saccharification The concentration concentration of the liquid can be accurately controlled.
According to the invention of (5), the residue separated as a solid content in the solid-liquid separation step is treated in a waste treatment facility that incinerates or melts waste, and power is generated using waste heat generated at that time. Since the steam extracted from the steam is used in the food waste concentration process and distillation process, it uses the thermal energy of the steam generated by the waste power generation, and is extracted as a liquid fuel that is easy to handle and easy to store. By constructing an ethanolization facility and an incineration (melting) facility adjacent to each other, only the sugar source, which is a useful component of organic waste, is extracted, and the remaining residue is incinerator (melting). Furnace).
According to the invention of (6), the oil component obtained by separation by the three-phase centrifugal separator can be used as a regenerated oil fuel after being treated by either or both of oil-water separation and filtration. .
According to the invention of (7), the regenerated oil fuel is used as a fuel for a waste treatment facility that incinerates or melts adjacent waste, and the fossil fuel used in the waste treatment facility is reduced or incinerated. Extracted steam that is generated when generating power using waste heat generated by combustion can be used for the concentration process and distillation process of the food waste.
According to the invention of (8), the oil component obtained by separation in the three-phase centrifugal separator can be used as a raw material for biodiesel fuel containing fatty acid methyl ester by transesterification, subcritical treatment or the like. it can.

  According to the present invention, a three-phase centrifugal separator that separates oil, saccharified liquid, and solids into three phases in a solid-liquid separation step of any one of saccharified liquid, fermentation liquid, and distillation waste liquid. By using it, while improving the recovery rate of the thermal energy contained in food waste, the ethanol manufacturing method with which the solid content which is the residue which generate | occur | produces at the time of a process is easy can be provided.

  Moreover, ethanol production costs can be reduced by effectively using the recovered steam of the incineration (melting) furnace.

  In addition, the incineration heat of the residue can be used for ethanol production, and can be used as a regenerated oil fuel.

The best mode and embodiment for carrying out the present invention will be described in detail with reference to FIGS.
1-4, 1 is garbage, 2 is a crushing and sorting device, 3 is a saccharifier, 4 is a screen, 5 is a three-phase centrifuge, 6 is a screen, 7 is a concentrator, 8 is a fermenter, 9 Is a distiller, 10 is a membrane separator, 11 is ethanol, 12 is a residue (solid content), 13 is oil, 14 is steam, 15 is a gasification melting furnace, 16 is a waste liquid, 17 is a regenerated oil treatment, 18 is A fueling process is shown, and the same symbols are used for the same elements to avoid duplication of explanation.
<First Embodiment>
FIG. 1 is a diagram illustrating a first embodiment of the ethanol production method of the present invention.

  First, the food waste 1 is crushed using a crushing / separating device 2, solids are removed as a residue 12, an enzyme such as glycol amylase is added in the saccharifier 3, and the starch is kept at about 60 ° C. Glucose is dissolved in water.

  Next, after separating impurities such as plastic, paper, bags, disposable chopsticks, metal, and crustaceans on the screen 4 using a filter-type squeezing machine, vibrating sieve device, punching metal and net, and removing them as a residue 12 In the three-phase centrifugal separator 5, the oil component, the saccharified solution component, and the solid component are separated into three phases, and the solid component is removed as a residue 12. The separated oil 13 can be used as a fuel for the gasification melting furnace 15, and since the saccharified liquid does not contain oil, there is no fear that the saccharified liquid will be clogged due to the oil adhering to the pipe. Moreover, the fall of the thermal efficiency of an ethanol manufacturing equipment can be prevented. In addition, since the temperature of the saccharified liquid immediately after the saccharifier 3 is 28 ° C. or higher, the fluidity of the oil can be increased to facilitate separation and recovery.

  Next, on the screen 6, the solids not separated in the solid-liquid separation step are removed using a screen having a mesh (aperture) of 0.1 mm to 10 mm and removed as a residue 12. After heating to about 160 ° C. to produce a glucose aqueous solution having a concentration of about 15 WT%, the yeast can eat glucose in the fermenter 8 to produce ethanol having a concentration of about 7.5 WT%.

  In the present invention, the heat source of the concentrator 7 is not limited, but the energy efficiency can be improved by using the medium-low temperature extraction steam 14 of about 200 ° C. used for the power generation equipment of the gasification melting furnace 15.

  Moreover, in ethanol fermentation, when the sugar concentration of the saccharified liquid from food waste is low, a Brix meter (refractometer) (not shown) is installed on the outlet side of the concentrator 7 in order to efficiently perform ethanol fermentation. The concentration of the saccharified solution is measured by measuring the concentration of the saccharified solution containing multiple types of sugar, salt, and SS (suspended solids), and discharging when the concentration exceeds a specified value. be able to.

  After sugar is converted into ethanol by ethanol fermentation, ethanol is separated from the ethanol fermentation liquor by the distiller 8, and then about 99.5% ethanol can be purified by the membrane separator 10.

  In addition, by using raw garbage, organic waste at this time contains not only sugar sources but also nutrient sources such as nitrogen sources, vitamins and minerals, and it is necessary to add new nutrient sources during ethanol fermentation. Absent. The produced ethanol can be used as a disinfectant, liquid fuel, or automobile fuel.

  It is also possible to use ethanol fermentation by loading sugar sources such as old rice and woody saccharified products. This can secure a low-cost nitrogen source that is said to account for half of the raw material costs in general ethanol fermentation.

Note that an incinerator can be used instead of the gasification melting furnace 15, and an existing furnace can be used as the incinerator or melting furnace.
<Second Embodiment>
FIG. 2 is a diagram illustrating a second embodiment of the ethanol production method of the present invention.

  In the second embodiment, the screen 4, the three-phase centrifuge device 5 and the screen 6 in the first embodiment are installed between the fermenter 8 and the distiller 9, and a part of the solid content. Fermentation efficiency can be improved by supplying to the fermenter 8. In addition, since the temperature of the saccharified liquid immediately after the saccharifier 3 is 28 ° C. or higher, the fluidity of the oil can be increased to facilitate separation and recovery.

Further, the features of the screen 4, the screen 6, and the Brix meter (refractometer) are the same as those in the first embodiment.
<Third Embodiment>
FIG. 3 is a diagram illustrating a third embodiment of the ethanol production method of the present invention.

  In the third embodiment, the screen 4 in the first embodiment is installed between the fermenter 8 and the distiller 9, and the three-phase centrifuge device 5 and the screen 6 are installed in the subsequent stage of the membrane separator 10. By doing this, a part of solid content can be supplied to the fermenter 8, the distiller 9, and the membrane separator 10, and ethanol production | generation efficiency can be improved. In addition, since the temperature of the saccharified liquid immediately after the distiller 9 is 40 ° C. or higher, the fluidity of the oil can be increased to facilitate separation and recovery.

  Further, the features of the screen 4, the screen 6, and the Brix meter (refractometer) are the same as those in the first embodiment.

  The ethanol production method of the present invention was applied to an ethanol production facility adjacent to the gasification melting furnace shown in FIGS.

  While the residue 12 generated from the ethanol production facility is processed in the gasification melting furnace 15, the middle and low temperature extracted steam generated in the gasification melting furnace 15 is extracted from the concentrator 4 and the distiller of the ethanol production facility. It has been confirmed that the thermal efficiency can be improved by using it as a heat source of No. 9.

  When 400 liters / day of ethanol was produced using 10 tons / day of garbage, 90% of the heat energy contained in the garbage could be recovered as ethanol, confirming the effect of the present invention.

  FIG. 5 and FIG. 6 are diagrams showing an embodiment in which oil separated using a three-phase centrifugal separator is regenerated.

  As shown in FIG. 5 and FIG. 6, the oil component obtained by separation in the three-phase centrifugal separator 5 is processed by a regenerated oil treatment 17 consisting of either or both of oil-water separation and filtration. It was found that it can be used as a regenerated oil fuel.

  Further, the regenerated oil fuel is used as a fuel for a waste treatment facility that incinerates or melts adjacent waste, and fossil fuel used in the waste treatment facility is reduced or incinerated and generated by combustion. It has been found that the extracted steam when generating power using waste heat can be used in the concentration process and distillation process of the food waste.

  Further, it has been found that the oil obtained by separation in the three-phase centrifugal separator 5 can be used as a raw material for biodiesel fuel containing a fatty acid methyl ester by a fueling treatment 18 including a transesterification reaction, a subcritical treatment and the like. .

  According to the present invention, residues generated in an ethanol production facility can be easily treated by treatment in a gasification melting furnace, and as a necessary heat source in the ethanol production facility, power generation in the gasification melting furnace can be performed. The use of the extracted steam used can increase the thermal efficiency, so it is extremely useful when installing a gasification melting furnace and ethanol production equipment close to each other, and has the potential for planning future ethanol production equipment. Be expected.

It is a figure which illustrates 1st Embodiment of the ethanol manufacturing method of this invention. It is a figure which illustrates 2nd Embodiment of the ethanol manufacturing method of this invention. It is a figure which illustrates 3rd Embodiment of the ethanol manufacturing method of this invention. It is a figure which shows the Example of the ethanol manufacturing method of this invention. It is a figure which shows the Example of the ethanol manufacturing method of this invention. It is a figure which shows the Example of the ethanol manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Garbage 2 Crushing sorter 3 Saccharifier 4 Screen 5 Three-phase centrifuge 6 Screen 7 Concentrator 8 Fermenter 9 Distiller 10 Membrane separator 11 Ethanol 12 Residue (solid content)
13 Oil content 14 Steam 15 Gasification melting furnace 16 Waste liquid 17 Recycled oil processing 18 Fuel processing

Claims (8)

  A method for producing ethanol by saccharifying, fermenting, and distilling food waste, wherein in the solid-liquid separation step of any one of the saccharified solution, the fermented solution, and the distilled waste solution, the oil component, the saccharified solution component, and An ethanol production method using a three-phase centrifugal separator that separates into three phases of solids.   2. The method for producing ethanol according to claim 1, wherein solids not separated in the solid-liquid separation step are removed using a screen having a mesh of 0.1 mm to 10 mm.   Before the solid-liquid separation step, it is characterized in that contaminants such as plastic, paper, bags, disposable chopsticks, metal, shellfish, etc. are separated using a filter-type squeezing machine, a vibrating sieve device, a punching metal and a net. The ethanol production method according to claim 1 or 2.   Measure the concentration of the saccharified solution containing multiple types of sugar, salt, and SS (suspended solids) using a Brix meter (refractometer), and discharge when the concentration exceeds the specified value. The method for producing ethanol according to any one of claims 1 to 3, wherein:   The residue separated as a solid content in the solid-liquid separation step is processed in a waste treatment facility that incinerates or melts the waste, and the steam extracted when generating power using the waste heat generated at that time is used as the food. It uses for the concentration process of a waste, and a distillation process, The ethanol manufacturing method as described in any one of Claim 1 thru | or 4 characterized by the above-mentioned.   6. The oil obtained by separating in the three-phase centrifugal separator is used as a regenerated oil fuel after being treated by either or both of oil / water separation and filtration. The ethanol manufacturing method as described in any one of these.   Waste heat generated by combustion by using the recycled oil fuel as a fuel for a waste treatment facility that incinerates or melts adjacent waste, and reduces fossil fuel used in the waste treatment facility or by incineration. The method for producing ethanol according to claim 6, wherein the extracted steam used when generating electric power using the gas is used in a concentration step and a distillation step of the food waste.   The oil obtained by separation in the three-phase centrifugal separator is used as a raw material for biodiesel fuel containing fatty acid methyl ester by transesterification, subcritical treatment, or the like. The method for producing ethanol according to any one of 6.

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