JP2010183863A - Method for producing ethanol from food waste and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method or apparatus for recovering ethanol in high efficiency in recovering ethanol from food waste. <P>SOLUTION: The method for producing ethanol from carbohydrate-containing food wastes includes carrying out a saccharification step of feeding food waste and water, stirring it and adjusting the temperature and then saccharifying the food waste with a diastatic enzyme, a fermentation step of after the saccharification, stirring and adjusting the temperature, feeding yeast and performing fermentation, a preliminary distillation step of after the fermentation, performing preliminary distillation by temperature adjustment without solid-liquid separation and a discharge step of discharging a waste fluid containing an insoluble substance after the preliminary distillation, by the same ethanol recovery apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and apparatus for producing ethanol from food waste discharged from kitchens such as restaurants and schools. More particularly, the present invention relates to a method and apparatus for producing ethanol by saccharifying, fermenting and distilling food waste discharged from kitchens such as restaurants and schools.

  In recent years, many so-called biofuels have been produced using wheat, corn, or the like as a raw material. This biofuel is preferable from the viewpoint of global environmental protection because it suppresses the use of finite fossil fuels such as oil and coal and makes a breakthrough from a fossil fuel dependent society.

  However, such wheat and corn are foods for humans and livestock, which poses a major problem that food supply is stagnant. From this point of view and the necessity of effective utilization of food waste that has been questioned for many years, an ethanol production method using food waste has been devised so far.

  For example, saccharification of raw garbage produces saccharified liquid, and saccharification part that lowers the hydrogen ion concentration of saccharified liquid mainly by fermentation of lactic acid by microorganisms living in the raw garbage, and alcohol fermentation using saccharified liquid An alcohol production system having a fermentation section and a distillation section that separates crude alcohol and distilled waste liquid has been devised (see, for example, Patent Document 1).

  In addition, a liquefaction tank into which raw materials containing a large amount of carbohydrates and liquefaction enzyme are added, a saccharification tank into which liquefaction product and saccharification enzyme are added, a fermenter to ferment the saccharification product, and the fermentation product is separated into solid and liquid and distilled. A method for producing a flammable liquid using equipment comprising a distillation tank has been devised (see, for example, Patent Document 2).

  However, in the case of solid-liquid separation after saccharification, the sugar content in the saccharified solution is not recovered, and in the case of solid-liquid separation after fermentation, it is not included in the separated insoluble matter. There was a problem that the ethanol contained in the fermented broth was not recovered.

  Furthermore, since separate equipment is required for each process such as the saccharification process and fermentation process, the equipment cost is high, a large equipment installation area is required, and the maintenance cost is high to operate the equipment group. was there.

  Therefore, an object of the present invention is to recover the sugar content in the saccharified solution contained in the insoluble matter solid-liquid separated after saccharification, and to recover the ethanol in the fermentation solution contained in the insoluble matter solid-liquid separated after fermentation. Providing a method and an apparatus capable of increasing the amount of ethanol recovered from food waste, and equipment of equipment groups arranged in each of a saccharification process and a fermentation process, which are processes for producing ethanol To provide a method and an apparatus that can reduce the cost, reduce the installation area of the facility, and reduce the maintenance cost for operating the facility.

  In the present invention, “preliminary distillation” means concentrating an ethanol solution by heating and distilling a fermentation broth containing insoluble matter.

  In order to solve the above problems, the invention of a method for producing ethanol from food waste according to claim 1 is a method for producing ethanol from food waste containing carbohydrates, after the food waste and water are added A saccharification step in which saccharification enzyme is introduced after saccharification and temperature adjustment is carried out, a fermentation step in which yeast is added after saccharification and after agitation and temperature adjustment, and fermentation is carried out after fermentation and temperature control without solid-liquid separation. The pre-distilling step for pre-distilling and the discharging step for discharging the waste liquid containing insoluble matter after the pre-distilling are performed by the same ethanol recovery device.

  The invention of an apparatus for producing ethanol from food waste according to claim 2 is an apparatus for producing ethanol from food waste containing carbohydrates, after the food waste and water are added, and after stirring and temperature adjustment A saccharification means for saccharification by introducing a saccharification enzyme, a fermentation means for fermentation by introducing yeast after saccharification, stirring and temperature adjustment, and a pre-distillation means for predistilling by fermentation without introducing solid-liquid separation after fermentation The same ethanol recovery apparatus is used for discharging the waste liquid containing the insoluble matter after the preliminary distillation.

  The invention according to claim 1 is capable of recovering the sugar content in the saccharified liquid contained in the insoluble matter solid-liquid separated after saccharification, and ethanol in the fermented liquid contained in the insoluble matter solid-liquid separated after fermentation. The effect that can be recovered.

  Since the saccharification process, fermentation process, and pre-distillation process can be performed in the same recovery tank body 2, the equipment arranged in each process can be reduced, so the capital investment cost is reduced and the equipment installation area is reduced. In addition, there is an effect that the maintenance cost is lowered to operate the equipment.

  The invention according to claim 2 has the same effect as the invention according to claim 1.

It is the schematic of an ethanol collection | recovery apparatus. It is the schematic of the stirrer installed in the tank from the collection tank main body peripheral wall. It is the schematic of the pump etc. which are made to send in a collection tank main body after attracting | sucking out of a collection tank main body. It is AA sectional drawing of the snake tube shape part of the heat-medium cooling tube 28 in FIG.1, FIG.2 or FIG.3.

  Hereinafter, embodiments of the present invention will be described in detail.

  An outline of an ethanol recovery apparatus for recovering ethanol from food waste will be described with reference to FIG. The ethanol recovery apparatus 1 has a substantially cylindrical recovery tank body 2, an inlet 10 for feeding food waste, water, saccharifying enzymes, and yeast provided on the upper part of the recovery tank body 2, and flowing steam or cooling water The heat refrigerant flow part 3 for adjusting the temperature of the solution 11 containing food waste, the stirring part 4 for stirring the solution 11 containing food waste, and the pre-distilled steam is cooled to ethanol The temperature of the cooling part 5 to be the liquid 60, the waste liquid discharge part 6 for discharging the waste liquid containing the insoluble matter after the pre-distillation, and the solution 11 containing the food waste in the recovery tank body 2 are measured. It is composed of temperature sensors 14, 15 and 16.

  The charging port 10 at the top of the recovery tank body 2 of the ethanol recovery device 1 is opened and closed by a lid.

  The thermal refrigerant flow section 3 includes a steam generator 21, an on-off valve 23 for opening and closing the steam flow path, a pump 22 with a cooling water tank for circulating cooling water, an on-off valve 24 for opening and closing the cooling water flow path, A water pipe 27, a thermal refrigerant pipe 28, a temperature sensor 29 for measuring the temperature of the steam or the cooling water, an on-off valve 25 for opening and closing the steam discharge path, and a steam release pipe 30 for releasing the steam into the atmosphere from the opening hole. The on-off valve 26 that opens and closes the cooling water return path, and the cooling water return pipe 31 that returns the cooling water that has passed through the collection tank body 2 to the pump 22 with the cooling water tank.

  And the thermal refrigerant pipe | tube 28 is installed in the lower part of the collection tank main body 2 at the lower part of the collection tank main body 2, as shown in FIG. Further, the thermal refrigerant pipe 28 can be circumscribed by the recovery tank main body peripheral wall 20 and a spiral pipe (not shown) can be installed. Further, the thermal refrigerant pipe 28 can be externally connected to the snake pipe at the lower part of the recovery tank body 2 and the peripheral wall 20 of the recovery tank body, and both the spiral pipes can be installed.

In addition, the thermal refrigerant fluidizing section 3 is linked to a temperature sensor 14, 15 or 16 that measures the temperature of the solution 11 containing food waste, and is saccharified and fermented according to the temperature of the solution 11 containing food waste. In addition, it is also possible to perform control (not shown in the control unit) of raising and lowering the temperature to a temperature suitable for preliminary distillation.

  The agitating unit 4 is connected to the drive motor 41, a rotation shaft 42 connected to the drive motor 41 via a speed change mechanism, suspended in the collection tank body 2 in the cylindrical axial direction of the collection tank body 2, and the rotation shaft 42. The rotary blades 43 rotate in the outer peripheral direction of the rotary shaft 42.

  As another type of the agitating unit 4, as shown in FIG. 2, a drive motor 44, a rotating shaft 45 provided in the collecting tank body 2 from the lower side wall of the collecting tank body 2, and a rotating shaft 45 are connected. A type constituted by a rotating blade 46 rotating in the outer peripheral direction of the rotating shaft 45 may be used.

  Further, as another type of the agitation unit 4, as shown in FIG. 3, a pump 47 and a solution circulation pipe 48 are installed, and the solution 11 containing the food waste is sucked from the lower part of the recovery tank body 2 and recovered. It may be of a type that circulates so as to be sent to the upper part of the main body 2.

  At the upper part of the recovery tank main body 2, there is provided a delivery port 17 for sending carbon dioxide gas generated by fermentation or steam generated when predistilling. A steam pipe 52 is connected to the delivery port 17, and an open / close valve 55 that opens and closes a flow path for steam and the like, and a temperature sensor 54 that measures the temperature of steam and the like are installed in the steam pipe 52.

  The steam pipe 52 is connected to a steam liquefying pipe 53 provided in the cooling unit 5 through a joint 63. The vapor liquefying tube 53 is manufactured from a flexible tube or a non-flexible tube.

  The on / off valve 55 is opened to discharge the carbon dioxide gas generated in the fermentation process and retained in the space 7 in the collection tank main body 2. The opening / closing of the on-off valve 55 is adjusted based on the relationship between the capacity of the recovery tank main body 2, the amount of the solution containing insoluble matter in the recovery tank main body 2, and the capacity of the space 7 in the recovery tank main body 2.

  A discharge port 18 for discharging waste liquid containing insoluble matter remaining in the recovery tank body 2 after preliminary distillation is installed at the lower part of the recovery tank body 2, and a discharge pipe 72 is connected to the discharge port 18. The discharge pipe 72 is provided with an open / close valve 73, the other end of the discharge pipe 72 is open, and the waste liquid discharged from the other end is collected in the waste liquid collection tank 71.

  And the vapor | steam containing the ethanol from the collection tank main body 2 by preliminary distillation is sent into the cooling unit 5 shown in FIG. 1, and the ethanol liquid 60 is obtained. The cooling unit 5 includes a cooling water tank 50 filled with the cooling water 57, a steam liquefaction pipe 53 set in the cooling water tank 50, a cooling water inlet pipe 61 that is connected to the lower part of the cooling water tank 50 and feeds the cooling water, An on-off valve 56 that opens and closes the cooling water flow path, a cooling water delivery pipe 62 that is connected to the upper part of the cooling water tank 50 and delivers cooling water, a temperature sensor 58 or 59 that measures the temperature of the cooling water 57, and the cooling water tank 50 It comprises an ethanol liquid recovery tank 51 that recovers an ethanol liquid that has been liquefied by passing through the inside.

  Then, the cooling unit 5 controls to open and close the on-off valve 56 according to the difference between the temperature of the cooling water 57 detected by the temperature sensors 58 and 59 and the high-temperature limit setting temperature of the cooling water 57 or the on-off valve 56 closing set temperature ( (Not shown in the control section).

  Next, an outline of a method for producing ethanol from food waste will be described.

  The food waste containing carbohydrate and dried to reduce the moisture content and water are introduced from the inlet 10 at the top of the recovery tank body 2 and the inlet 10 is closed.

  The input amount of food waste relative to the weight of water is set according to the moisture content of the food waste, and the input amount of saccharifying enzyme is set according to the total weight of the food waste and water.

  Moreover, the saccharification temperature and saccharification time for promoting saccharification are set according to the input amount of food waste, water and saccharifying enzyme, and the type of saccharifying enzyme.

  After reaching the set saccharification temperature, the inlet 10 is opened, saccharification enzyme is introduced, and the inlet 10 is closed. And in order to accelerate | stimulate saccharification of the solution 11 containing a food waste, while stirring the solution 11 containing an insoluble matter by the stirring part 4, the solution 11 containing the food waste among the temperature sensors 14, 15 or 16 is included. A steam generator that controls the flow of the heat medium when the temperature should be raised due to the difference between the set saccharification temperature and the temperature sensor detection temperature so that the temperature of the temperature sensor in contact with the temperature can be maintained at a preset saccharification temperature. 21 is operated, the on-off valve 23 and the on-off valve 25 are opened, and when the temperature is to be lowered, the on-off valve 24 and the on-off valve 26 are opened by operating a pump with a cooling water tank that controls refrigerant flow.

  Cool to fermentation temperature after saccharification. After reaching the fermentation temperature, the inlet 10 is opened, yeast is introduced, and the inlet 10 is closed. And in order to accelerate | stimulate fermentation of the saccharified liquid 12 containing the insoluble matter, fermentation time is set according to the quantity of the saccharified liquid 12, and the kind and input amount of yeast.

  In order to promote fermentation, the saccharified solution 12 containing the insoluble matter is stirred by the stirring unit 4, and the temperature sensor 14, 15, or 16 that is in contact with the saccharified solution 12 among the temperature sensors 14, 15 is set in advance. If the temperature should be raised due to the difference between the set fermentation temperature and the temperature sensor detection temperature, the steam generator 21 that controls the flow of the heat medium is activated and the on-off valve 23 and the on-off valve 25 are opened so that the temperature can be maintained. If the temperature should be lowered, the cooling water tank pump 22 for controlling the refrigerant flow is operated, and the on-off valve 24 and the on-off valve 26 are opened.

  At the time of fermentation, in order to avoid an increase in pressure in the recovery tank main body 2 due to carbon dioxide gas generated by fermentation, the capacity of the recovery tank main body 2, the amount of the solution containing insoluble matter in the recovery tank main body 2, and the recovery tank main body The opening / closing of the on-off valve 55 is adjusted based on the relationship with the capacity of the space 7 in 2.

Steam generation that controls the flow of the heat medium so that the temperature of the temperature sensor 14, 15 or 16 that is in contact with the fermentation broth 13 can be maintained at a preset predistillation temperature in order to promote predistillation. The device 21 is operated and the on-off valve 23 and the on-off valve 25 are opened. Moreover, at the time of preliminary distillation, the on-off valve 55 provided in the upper part of the collection tank main body 2 is opened to flow the pre-distilled steam.

  After preliminary distillation, the waste liquid containing the insoluble matter remaining in the lower part of the recovery tank body 2 is discharged from the discharge port 18 by opening the on-off valve 73 and recovered in the waste liquid recovery tank 71.

  Further, the pre-distilled vapor is liquefied in the process of flowing in the vapor liquefaction pipe 53 set in the cooling water tank 50, and the liquefied ethanol liquid 60 is poured out from the terminal portion of the vapor liquefaction pipe 53 to be an ethanol liquid recovery tank. 51 is collected.

  Since the temperature of the cooling water 57 rises due to the predistilled steam flowing in the vapor liquefaction pipe 53, the temperature sensor 58 is used so that the predistilled vapor liquefies in the process of flowing in the vapor liquefaction pipe 53. Alternatively, when the temperature of the cooling water 57 detected by 59 reaches a preset cooling water 57 high temperature limit temperature, the on-off valve 56 is opened and cooling water is fed from the cooling water feed pipe 61 to cool the cooling water 57. Then, the control is performed to close the on-off valve 56 when the preset on-off valve 56 closing temperature is reached.

  Next, although an Example is given and this invention is demonstrated, this invention is not limited by an Example.

  The food waste containing carbohydrate and dried at a drying temperature of 80 ° C. to 100 ° C. to reduce the moisture content and the water are introduced from the inlet 10 at the top of the recovery tank body 2.

  As for the food waste, 10 kg corresponding to about 25% by weight is added to 40 kg of water.

  Steam is generated while appropriately rotating the stirring unit 4 until the saccharification temperature of the temperature sensor 14, 15 or 16 that is in contact with the solution 11 containing food waste reaches 55 ° C. to 60 ° C. The steam from the vessel 21 is opened by opening the on-off valve 23 and the on-off valve 25 to cause the steam to flow in the thermal refrigerant pipe 28, and after reaching the set saccharification temperature, the saccharifying enzyme is introduced and the inlet 10 is closed.

  The saccharifying enzyme is added in an amount of 0.005% to 0.2% by weight based on the total amount of food waste and water.

  And the flow of a heat medium or a refrigerant | coolant is controlled, rotating the stirring part 4 suitably so that setting saccharification temperature may be maintained for about 24 hours.

  After the saccharification, the stirring unit 4 is kept until the fermentation temperature of the temperature sensor in contact with the saccharified liquid 12 containing the insoluble matter among the temperature sensors 14, 15 or 16 reaches a temperature range of 30 ° C to 35 ° C. While appropriately rotating, the pump 22 with a cooling water tank that controls the flow of the refrigerant is operated, the on-off valve 24 and the on-off valve 26 are opened, the cooling water flows in the thermal refrigerant pipe 28, and the temperature is lowered to cool to the set fermentation temperature. To do.

  After reaching the set fermentation temperature, the inlet 10 is opened, and yeast is added at 0.05 wt% to 0.5 wt% with respect to the total weight of the food waste and water, and the inlet 10 is closed. And the flow of a heat medium or a refrigerant | coolant is controlled, rotating the stirring part 4 suitably so that preset fermentation temperature may be maintained for 48 hours.

  In order to pre-distill after fermentation, the temperature of the temperature sensor 54 installed in the steam pipe 52 is raised until the temperature of the detected steam reaches 78 ° C. to 98 ° C., and the flow of the heat medium so as to maintain the detected steam temperature. Is controlled, and pre-distillation is performed. Finally, pre-distillation is terminated when the ethanol concentration generated from the vapor liquefaction tube 53 becomes 0.5% or less.

  The vapor generated by the preliminary distillation is liquefied by flowing in the cooling unit 5, becomes an ethanol liquid 60, and is recovered in the ethanol liquid recovery tank 51.

  The recovery rate of ethanol obtained by the main distillation in the distillation column after the preliminary distillation according to the above example is that 2.0 liters of ethanol having an ethanol concentration of 90% or more can be recovered from 10 kg of food waste, and after the conventional fermentation Ethanol recovery rate compared to 1.8 liter recovery of ethanol with 90% or higher ethanol concentration when solid-liquid separation is performed with a solid-liquid separator (trade name Slit Saver, Model SS-28, manufactured by Kendensha Co., Ltd.) Was improved by about 10%.

DESCRIPTION OF SYMBOLS 1 Ethanol collection | recovery apparatus 2 Recovery tank main body 3 Thermal refrigerant flow part 4 Stirring part 5 Cooling part 6 Waste liquid discharge part 7 Space 10 Input port 11 Solution containing food waste 12 Saccharified liquid containing insoluble matter 13 Insoluble matter Fermentation liquid 14 temperature sensor 15 temperature sensor 16 temperature sensor 17 delivery port 18 discharge port 20 recovery tank body peripheral wall 21 steam generator 22 pump with cooling water tank 23 on-off valve 24 on-off valve 25 on-off valve 26 on-off valve 27 cooling water pipe 28 Thermal refrigerant pipe 29 Temperature sensor 30 Steam release pipe
DESCRIPTION OF SYMBOLS 31 Cooling water return pipe 41 Drive motor 42 Rotating shaft 43 Stirring blade 44 Drive motor 45 Rotating shaft 46 Stirring blade 47 Pump 48 Solution circulation pipe 50 Cooling water tank 51 Ethanol liquid recovery tank 52 Steam pipe 53 Steam liquefaction pipe 54 Temperature sensor 55 On-off valve 56 On-off valve 57 Cooling water 58 Temperature sensor 59 Temperature sensor 60 Ethanol liquid 61 Cooling water inlet pipe 62 Cooling water delivery pipe 63 Fitting 71 Waste liquid recovery tank 72 Drain pipe 73 On-off valve

JP 2006-325577 A JP 2006-325518 A

Claims (2)

  A method for producing ethanol from a food waste containing carbohydrates, a saccharification step in which saccharification enzyme is introduced after saccharification enzyme is added after food waste and water are added and stirring and temperature adjustment are performed, and after saccharification, stirring and temperature The same fermentation process that ferments by adding yeast after adjustment, the pre-distillation process that pre-distills by fermentation without temperature separation after solidification, and the discharge process that discharges waste liquid containing insoluble matter after pre-distillation A method for producing ethanol from food waste, characterized in that it is carried out with an ethanol recovery apparatus.   A device for producing ethanol from food waste containing carbohydrates, saccharification means for saccharification by adding saccharification enzyme after the food waste and water are added and stirring and temperature adjustment, and after saccharification, stirring and temperature Fermentation means for fermenting by adding yeast after adjustment, predistillation means for predistilling by temperature adjustment without solid-liquid separation after fermentation, and discharge means for discharging waste liquid containing insoluble matter after predistillation are the same An apparatus for producing ethanol from food waste, characterized in that it is carried out with an ethanol recovery apparatus.

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