JP3974568B2 - Food waste disposal method - Google Patents

Description

  The present invention relates to a method for treating food waste.

  Food waste is inevitably generated every day for people to live, and the amount of food waste is enormous. Disposing such food waste safely and effectively leads people to live a healthy social life. One of the most important issues above.

  Currently, solid (solid) food waste, such as leftover food and expired foods, among food waste generated in food factories and kitchens, is mainly disposed of by incineration or landfill. Various treatments are applied to feed or fertilizer.

  In addition, liquid food wastes with high water content, such as leftovers and beverage products that have expired, are mostly disposed of by ocean dumping, and practical methods for converting them into feed and fertilizers have been found. Not.

  However, incineration of food waste is very expensive, and the incineration of the entire amount of food waste that is increasing year by year is an increase in the number of incineration facilities. Since this is a very difficult situation, it is not a realistic processing method. On the other hand, landfill disposal of food waste is not a realistic treatment method because landfill disposal sites have decreased and it is extremely difficult to find new landfill disposal sites in the future. In addition, it is difficult to separate food wastes into feed or fertilizers because it is difficult to separate packaging materials represented by plastic bags, etc. contained in food wastes. Not in. In particular, most liquid food wastes with high water content, such as leftovers and expired beverage products, have been disposed of by ocean dumping. An effective treatment method has not been found.

  Thus, finding a method for safely and effectively treating food waste containing liquid food waste has become a problem in current food waste treatment.

Therefore, the present inventor mixes solid food waste and liquid food waste, and then mixes them in a fungus bed containing fermentation bacteria to ferment food waste, which occurs during fermentation. A method for treating food waste by evaporating water contained in food waste by heat of fermentation has been devised (see Patent Document 1).
JP 2002-11432 A

  However, in the above-described method for treating food waste, the food waste can be efficiently treated, but when the food waste contains a large amount of water, There was a risk that the processing time would be longer.

  Thus, as a result of intensive studies on the above-mentioned food waste treatment method, the present inventor has arrived at the present invention capable of shortening the treatment time.

  That is, in the present invention, after adding starch to food waste in which solid food waste and liquid food waste are mixed, the food waste is fermented by mixing in the fungus bed containing fermentation bacteria. It was decided that the starchy material would be α-ized by the heat of fermentation generated during fermentation and the water remaining in the food waste would be evaporated by the heat of fermentation.

  The present invention is implemented in the form described above, and has the following effects.

  That is, in the present invention, after adding starch to food waste in which solid food waste and liquid food waste are mixed, the food waste is fermented by mixing in the fungus bed containing fermentation bacteria. The starch is converted to alpha by the heat of fermentation generated during fermentation, and the water remaining in the food waste is evaporated by the heat of fermentation, so that most of the water contained in the food waste is crystallized water. As a result, it is possible to reduce the amount of water evaporated by fermentation heat, thereby shortening the processing time required for water evaporation.

  The method for treating food waste according to the present invention includes mixing and deodorizing aqua regia in solid food waste and liquid food waste, respectively, and then solid food waste and liquid food. The waste is mixed and crushed into a paste-like food waste, the plastic is removed by sieving the paste-like food waste, and then starch is added to the paste-like food waste And mixing sodium carbonate or calcium carbonate to neutralize food waste, producing sodium nitrate or calcium nitrate as a nutrient source for fermenting bacteria and then fermenting it into the fungus bed containing the fermenting bacteria, Utilizing the heat of fermentation generated during fermentation, the starch contained in the paste-like food waste is converted to alpha, and at the same time, the remaining water is evaporated by the heat of fermentation. Food waste and without, by sieving causes sterile dry part of the powdered food waste generated feed, is to reuse the remaining powdered food waste as a secondary mushroom bed.

  In this way, after mixing the solid food waste and the liquid food waste, the food waste is fermented by mixing in the fungus bed containing the fermenting bacteria, and by the heat of fermentation generated during fermentation By evaporating the moisture contained in food waste, it is possible to evaporate the moisture contained in liquid food waste in an inexpensive facility without having to prepare an expensive facility for dehydration and drying treatment. It is possible to process liquid food waste at low cost.

  In addition, starch is added to food waste, and this starch is made into α by the heat of fermentation generated during fermentation using moisture contained in food waste, so it is contained in food waste. Can be taken into the starch that has been pregelatinized as crystal water, thereby reducing the amount of water evaporated by fermentation heat and reducing the processing time. it can.

  Below, the processing method of the food waste which concerns on this invention is demonstrated concretely, referring FIG.

  First, solid food waste such as leftover food or expired foods and liquid food waste with high water content such as leftover or expired beverage products are used in food factories and kitchens. Recover from.

  Next, aqua regia, which is a mixed liquid of concentrated hydrochloric acid and concentrated nitric acid as deodorant 3, is mixed with solid food waste and liquid food waste (volume ratio of nitric acid and hydrochloric acid is 1: 3). Each of the mixed liquids is mixed to a pH of about 1 to 2, and then stored in the storage tanks 1 and 2.

  In this way, by mixing aqua regia into solid food waste or liquid food waste, it is possible to prevent the food waste from being spoiled by the action of strong acid, and to prevent the generation of bad odor due to the spoilage of the food waste. In this way, food waste can be deodorized.

  Next, after mixing the solid food waste and the liquid food waste by the mixer 4, the food waste is crushed in the liquid by the crusher 5. Thereby, paste-like food waste is produced | generated.

  Thus, by crushing food waste in the liquid, generation of dust during crushing can be prevented.

  Next, the solid waste such as plastic is removed by screening the pasty food waste using the vibrating sieve 6 and separated and accommodated in the waste tank 7.

  In this way, by mixing solid food waste and liquid food waste, crushing and screening, it is easy to remove plastics such as packaging materials contained in food waste without human intervention. The food waste can be processed smoothly.

  Next, 5% by weight of starch is added to the paste-like food waste, and sodium carbonate or calcium carbonate neutralizing agent 8 is mixed therein.

  This neutralizes the aqua regia mixed in the paste-like food waste and makes it easy to handle, and reacts with nitric acid contained in the aqua regia to react with sodium nitrate as a nutrient source for fermenting bacteria or Calcium nitrate is produced. In addition, hydrochloric acid contained in aqua regia reacts with sodium carbonate or calcium carbonate to become sodium chloride or calcium chloride.

  Thus, by mixing sodium carbonate or calcium carbonate into food waste, it is possible to produce sodium nitrate or calcium nitrate as a nutrient source for fermenting bacteria. The food waste can be processed smoothly in a short time.

  Next, using the fermenter 9, the neutralized paste-like food waste is mixed into the bacterial bed 10 containing the fermenting bacteria. At that time, water is added as necessary so that the moisture content becomes about 50% to 60% in a state where the paste-like food waste is mixed in the fungus bed 10. In the figure, 15 is a blower and 16 is an intake pipe.

  Here, the fungal bed refers to rice sugar or corn used for feed or the like mixed with microorganisms (for example, lactic acid bacteria) having an action of decomposing organic substances such as carbohydrates, and the water content is 10% to 20%. The percentage of microorganisms stored stably.

  Then, the microorganisms contained in the fungus bed 10 start to act by increasing the water content, grow using moisture, calcium nitrate, and sodium nitrate as nutrients, and decompose organic substances contained in the food waste inside the fermenter 9. . That is, the food waste is aerobically fermented inside the fermenter 9.

  As the fermentation proceeds, fermentation heat is generated, and after about 12 hours, the temperature of the fungus bed 10 increases to 70 ° C. or more sufficient to make the starchy material into α, and after about 14 hours, the fermentation is completed.

  In that case, the starch substance added to the paste-like food waste by fermentation heat couple | bonds with the water | moisture content contained in a food waste, and produces | generates alpha starch.

  In addition, the remaining water that has not contributed to the pre-gelatinization of the starch is evaporated by the heat of fermentation generated during the fermentation, and as a result, the powdered food waste having a moisture content of about 20% to 30% Become.

  In addition, the ratio of the water taken into the starch as water of crystallization when the starch is pregelatinized and the water evaporated by the fermentation heat is about 3: 2, and a large amount of water contributes to the pregelatinization of the starch. ing. Therefore, after the starch has been completely gelatinized, it becomes a powdery food waste in a moist state and can be used as it is as a raw material for the secondary microbial bed and feed described later.

  As described above, in this embodiment, after mixing solid food waste and liquid food waste, the food waste is fermented by mixing in the fungal bed 10 containing fermentative bacteria, and the fermentation is performed. Because the moisture contained in food waste is evaporated by the heat of fermentation generated in the food, it is an inexpensive facility, especially in liquid food waste, without the need for expensive equipment for dehydration and drying treatment. It is possible to evaporate the water content, and to process liquid food waste at low cost.

  In addition, starch is added to food waste, and the starch is made alpha by the heat of fermentation generated during fermentation using the water contained in the food waste. Can be reduced, thereby shortening the processing time. For example, when no starch was added, it became a powdery food waste in about 20 hours. However, when 5% by weight of starch was added to the same food waste, the same result was obtained in about 14 hours. It became powdery food waste, and the processing time could be shortened by about 6 hours.

  In addition, the powdered food waste, whose moisture content has been evaporated by fermentation heat, contains a large amount of microorganisms that have the effect of decomposing organic substances such as carbohydrates. can do.

  In this way, by reusing the food waste in which the moisture content is evaporated by fermentation heat as a secondary microbial bed, it is not necessary to generate the microbial bed 10 every time the food waste is processed, and at a low cost. It is possible to treat food waste semipermanently.

  On the other hand, a part of the powdered food waste (about 30% of the total volume) from which the moisture content has been evaporated by fermentation heat is taken out from the fermenter 9 and sterilized and dried using a sterilization dryer 11, and then The vibrating screen 12 is used to screen and waste on the screen is separated and accommodated in the waste tank 13 and the feed is separated and accommodated in the feed tank 14.

  Thus, by producing a feed by sterilizing and drying a food waste whose moisture content has been evaporated by fermentation heat, the food waste can be effectively used as a feed raw material.

Explanatory drawing which shows the processing method of the food waste which concerns on this invention.

Explanation of symbols

1,2 Storage tank 3 Deodorant 4 Mixer 5 Crusher
6,12 Vibrating sieve
7,13 Waste tank 8 Neutralizer 9 Fermenter
10 Bacteria bed
11 Sterilization dryer
14 Feed tank

Claims (1)

  After adding starch to food waste that is a mixture of solid food waste and liquid food waste, ferment the food waste by mixing it into the fungus bed containing fermenting bacteria, and during fermentation A method for treating food waste, characterized in that the starchy substance is converted to alpha by the generated fermentation heat and the water remaining in the food waste is evaporated by the heat of fermentation.

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