JP2005211805A - Method for producing ethanol in waste incineration facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing ethanol in waste incineration facilities, in which ethanol is produced in high production efficiency and the amount of the waste to be incinerated is reduced by adopting an existing waste recovering system and existing waste incineration facilities as they are and mixing recovered woody waste with selectively recovered garbage while incinerating combustible organic matter at the same time. <P>SOLUTION: Ethanol is produced by mixing garbage in the woody waste selectively recovered from the combustible waste to be conveyed in waste incineration facilities, converting the obtained mixture into sugars, biologically converting the obtained sugars, and distilling the biologically converted sugars. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing ethanol in a waste incineration facility, and in particular, using an existing waste incineration facility, selectively using wood waste from combustible waste carried into the waste incineration facility. In a waste incineration facility that improves the ethanol production efficiency and reduces the amount of waste incineration by collecting and mixing raw garbage with this, followed by saccharification, then bioconversion, and distillation The present invention relates to an ethanol production method.

Conventionally, waste materials and pruning waste discharged from construction and lumber mills, agricultural waste such as rice straw, straw, sugarcane and corn, pulp sludge, waste from textile factories, waste from printing or bookbinding factories, A method for producing ethanol from biomass resources such as woody industrial waste (cellulosic waste) such as waste paper has been proposed.
For example, a method of producing ethanol through a saccharification step in which the recovered biomass resource is hydrolyzed or steamed to obtain a saccharide raw material, a fermentation step in which this is fermented, and an ethanol separation step in which ethanol is further separated by distillation, Alternatively, the recovered biomass resource is pulverized, and water is added to form a slurry, which is then maintained in a subcritical or supercritical state of water to decompose and saccharify the polysaccharide contained in the biomass, and then ferment A method of producing ethanol, a saccharification step in which an enzyme solution is allowed to act on cellulosic waste to produce sugar, and a fermentation step in which fermentation is performed using the sugar-containing solution produced in this saccharification step, followed by an enzyme There is a method of producing ethanol through a production process.

By the way, in the conventional method for producing ethanol from woody industrial waste (cellulosic waste), the existing waste collection system that collects general garbage and a collection facility such as a garbage collection vehicle are not used as they are, but woody. A new collection system that separates and collects only system waste is adopted.
In addition, when ethanol is produced from wood-based industrial waste (cellulosic waste), the necessary heat energy is obtained in the saccharification treatment, fermentation treatment, and distillation steps, respectively. The heat energy generated from the fossil fuel is input to the outside.

For this reason, the conventional method for producing ethanol from woody industrial waste (cellulosic waste) requires a new recovery system and transportation cost for woody waste, and also includes saccharification, fermentation, and ethanol. In each process such as distillation, there is a problem that heat energy from the outside is required for heating and ethanol produced is expensive.
Furthermore, since the garbage contained in the waste treatment facility has a high moisture content of 95% or more, in order to incinerate it, a large amount of heat energy is required and the combustion temperature in the combustion furnace is lowered. However, there was a problem that it was incompletely burned and was incinerated despite being a precious biomass resource that contained abundant starch and cellulose.
JP-A-11-169188 JP 2001-262162 A JP 2002-159954 A

  In view of the problems of the conventional ethanol production method described above, the present invention adopts the existing waste collection system and waste incineration facility as they are, and mixes the collected wooden waste with garbage and burns it at the same time. An object of the present invention is to provide a method for producing ethanol in a waste incineration facility that improves ethanol production efficiency and reduces the amount of waste incineration while performing incineration processing of organic matter.

  In order to achieve the above object, the ethanol production method in the waste incineration facility according to the present invention is a method of selectively recovering the wood waste selectively recovered from the combustible waste carried into the waste incineration facility. After mixing trash and performing saccharification treatment, biotransformation treatment and distillation are performed to produce ethanol.

  In this case, the mixing of the wooden waste and the garbage can be adjusted to a water content of 80 to 95% suitable for this saccharification treatment.

  Moreover, the residual heat generated at the time of waste combustion in the waste incineration facility can be used as a heat source for saccharification treatment, bioconversion treatment and distillation.

  In addition, using the residual heat generated during the combustion of waste at the waste incineration facility, the residue after saccharification and bioconversion processing is reduced to a moisture content that can be self-combusted, incinerated at the waste incineration facility, and then the incineration ash Can be recycled as landfill or various materials.

  According to the ethanol production method in the waste incineration facility of the present invention, raw garbage is mixed with the wooden waste selectively collected from the combustible waste carried into the waste incineration facility, and saccharification treatment is performed. After that, biotransformation treatment and distillation are performed to produce ethanol, so existing waste collection systems and waste incineration facilities can be used, so new collection systems and transportation costs are required. Therefore, by mixing raw waste with a high water content with wooden waste and supplying it to the incinerator, the temperature inside the furnace can be prevented from dropping, and the components suitable for ethanol production contained in the raw waste can be efficiently used. The amount of waste incineration at a waste incineration facility can be reduced.

  In addition, by adjusting the mixing of wood-based waste and raw garbage to a water content of 80 to 95% suitable for this saccharification treatment, the amount of waste incineration can be reduced and the temperature in the furnace can be prevented from lowering. It becomes possible and can produce ethanol efficiently.

  In addition, by using the residual heat generated during the combustion of waste at a waste incineration facility as a heat source for saccharification, bioconversion and distillation, no other heat source is required, thus reducing the production cost of ethanol. Can do.

  In addition, using the residual heat generated during the combustion of waste at the waste incineration facility, the residue after saccharification and bioconversion processing is reduced to a moisture content that can be self-combusted, incinerated at the waste incineration facility, and then the incineration ash By recycling as a landfill or various materials, other thermal energy is not required for drying the residue, or it can be made as small as possible, and incineration can be easily performed.

  Hereinafter, an embodiment of an ethanol production method in a waste incineration facility of the present invention will be described based on a flow chart of an ethanol production process shown in FIG.

As waste to be brought into the waste incineration facility, in addition to raw garbage discharged from ordinary households, agricultural waste such as waste and pruning waste from construction and sawmills, rice straw, straw, sugarcane, corn, etc. Waste, pulp sludge, waste from textile factories, waste from printing or bookbinding factories, wood-based industrial waste (cellulosic waste) such as waste paper.
Of these, wood-based industrial waste is used as a biomass resource, but in the present invention, this wood-based industrial waste is also added with raw garbage as a high-quality sugar resource rich in starch and cellulose. In addition, saccharides such as glucose are generated and processed by saccharification using existing systems as flammable waste.
In addition, the collection and collection system for waste such as garbage and wood-based waste brought into facilities that incinerate these combustible wastes is collected using existing systems. By collecting by time or place, it is not necessary to create a new waste collection system.

Carrying in combustible waste to a facility that incinerates, but not limited, for example, recovered waste A carried in using a garbage truck, etc., is garbage / woody waste B and others The other incineration waste C is mixed and is classified into garbage / woody waste B and other incineration waste C in the waste incineration facility.
Other incineration waste C is temporarily stored in the garbage pit 1 having a required capacity and stirred, and then sent to the incinerator 2 where it is incinerated. The incinerated ash as a residue of the incinerated waste C that has been incinerated is temporarily stored in the ash pit 3 and then converted into slag D in the ash melting facility 4 and recycled to construction materials or in landfills. The incineration ash is disposed of in landfill.

In this case, raw garbage is a high-quality sugar resource that contains abundant starch and cellulose. However, because of its high water content (may exceed 95%), saccharification treatment and bioconversion treatment in the subsequent steps are also required. Since the glucose concentration is lowered, the ethanol concentration produced is also low, and the distillation efficiency in the distillation process is deteriorated. In order to prevent this, it is necessary to adjust the moisture content of raw garbage. This is generally low water content (depending on the type of recovered material, the weather at the time of recovery, etc., but often less than 50%) and each of the above-mentioned high-water content garbage. By adjusting the mixing ratio based on the rate, the water content of raw garbage / woody waste B is adjusted to a water content of 80-95% suitable for saccharification, so that ethanol production efficiency is improved. To.
Here, it is already known that two molecules of ethanol are bioconverted from one molecule of glucose by yeast. From this, when the raw material before the saccharification treatment has a high water content, it means that the solid matter concentration decomposed into glucose by the saccharification treatment is low, and naturally, bioconversion is performed, and the resulting ethanol concentration is also low. Therefore, excessive energy is required to perform distillation of a low-concentration ethanol mixed solution. Moreover, when the raw material before a saccharification process is a low water content, stirring and mixing with a sulfuric acid or an enzyme agent in a saccharification process process becomes inadequate, and saccharification process efficiency falls. For these reasons, it is desirable to mix saccharification treatment by mixing raw garbage with a high water content and woody waste with a low water content, keeping the water content of the mixture at about 95 to 80%.

On the other hand, the separated garbage / wood waste B is crushed using a crusher etc. to a size suitable for saccharification performed in the subsequent process, and this crushed garbage / wood The system waste B is supplied into the saccharification treatment tank 8 and necessary saccharification treatment is performed here.
In this case, the garbage in the garbage / woody waste B capable of producing sugar such as glucose may be subjected to direct saccharification in some cases, but the construction / used paper / pruning / rice In the case of wooden waste such as straw, it is necessary to crush the raw material to make it finer.
As a method for performing saccharification treatment in this saccharification treatment tank 8, there are a method of heating and pressurizing with sulfuric acid, a method of using a cellulase-based and / or amylase-based enzyme agent, etc., but this is not particularly limited. In the case of using an enzyme agent, the enzyme reaction is promoted by subjecting the raw material to an alkali dipping treatment or a dilute acid in advance and performing a heat treatment or a steaming explosion treatment.

In this saccharification treatment tank 8, the cellulose and / or starch in the raw material is saccharified into glucose. The solution after saccharification treatment containing glucose is sterilized or sterilized by heating, ultraviolet ray or ozone treatment, but when sterilization or sterilization treatment is not required when sulfuric acid is added and heat treatment is performed. There is also. This sterilization or sterilization treatment is not limited to the method if the bacteria in the raw material are killed or most of them are killed, but it is preferably performed before the saccharification treatment. In addition, when a thermostable enzyme agent having an optimum temperature of 70 ° C. or higher is used, sterilization or sterilization treatment is not particularly required.
The glucose-containing solution that has been subjected to the saccharification treatment and sterilized or sterilized is then supplied into the bioconversion treatment tank 9 and converted into an ethanol mixed solution in the bioconversion treatment tank 9. In this bioconversion treatment tank 9, yeast or the like is used and is converted into ethanol in the bioconversion treatment tank 9.
In ethanol fermentation, yeast may be used, but it is also an effective means to use a mutant or genetically modified bacterium that produces ethanol with enhanced alcohol tolerance or increased ethanol production ability.

  In addition, when ethanol-producing bacteria such as yeast are used in the bioconversion treatment tank 9, ethanol E is recovered. However, if the present invention is used, a biodegradable plastic using lactic acid-producing bacteria is used in the bioconversion treatment tank 9. It is also possible to produce lactic acid as a raw material. Similarly, if this system is used, other microorganisms can be used to produce useful substances.

  Since this ethanol mixed solution has a low ethanol concentration, it is sent to the distillation step 10 so as to have a required concentration. The ethanol mixed solution sent to the distillation step 10 is distilled here and recovered as ethanol E having a required concentration.

  Moreover, since the residue (residue) F generated by the saccharification treatment and the bioconversion treatment performed in the saccharification treatment tank 8 and the bioconversion tank 9 has a high water content, it does not self-combust as it is, so that it can self-combust. To the required moisture content. For this reason, this residue (residue) F is sent to the dehydration / drying process step 11 where the dehydration / drying process is performed to reduce the moisture content to a predetermined level at which it can burn, and then returned to the garbage pit 1 for incineration. Is done.

In addition, the ethanol production process can be broadly divided into three processes of saccharification treatment, bioconversion treatment, and distillation, but any process requires heat energy. By utilizing the residual heat generated during the combustion of the waste in the waste incineration facility as the heat source required for this ethanol production, it is not necessary or suppressed to input energy from the outside such as fossil fuel.
As a result, in the prior art, a new disposal system for the residue F generated mainly in the saccharification treatment tank 8 and the like was required, but as in the present invention, ethanol was produced in a waste incineration facility. In this case, since a facility for incineration, landfill disposal, or recycling to construction materials or the like is already provided, it is not necessary to establish a new one, and a completed processing system can be used.
Furthermore, by using the residual heat generated during waste combustion at the waste incineration facility, the residue after saccharification treatment and bioconversion treatment can be reduced to a moisture content capable of self-combustion by an inexpensive method. It is also possible to incinerate with a waste incineration facility and recycle as landfill or various materials.

When this residue F is subjected to incineration after dehydration and drying, the residual heat a generated in the incinerator 2 is converted into steam by the boiler 5 and is converted into a saccharification treatment tank 8, a bioconversion treatment tank 9, and a distillation step 10. Then, it is sent to the dehydration / drying process step 11 where it is used as a heat source.
The exhaust gas generated from the incinerator 2 converted into the residual heat a is released into the atmosphere as exhaust gas b after removing harmful substances by the exhaust gas treatment facility 6.

  As mentioned above, although the ethanol production method in the waste incineration facility of the present invention has been described based on the examples, the present invention is not limited to the configurations described in the above examples, and appropriately within a range not departing from the gist thereof. The configuration can be changed.

  As described above, the ethanol production method in the waste incineration facility according to the present invention adjusts the mixing ratio of woody waste with low water content and raw garbage with high water content using the water content as an index, saccharification treatment, bioconversion Since it has the characteristic of improving ethanol production efficiency by obtaining a process and a distillation process of ethanol, it can be suitably used for applications in which ethanol production using existing waste incineration facilities is inexpensive. In addition, for example, it can be used for the purpose of producing lactic acid as a raw material for biodegradable plastics using lactic acid-producing bacteria, and for the purpose of producing useful substances using other microorganisms.

It is a flowchart of the ethanol manufacturing process using a waste incineration facility.

Explanation of symbols

A Recovered waste B Garbage / woody waste C Other incineration waste D Slag E Ethanol a Residual heat b Exhaust gas 1 Garbage pit 2 Incinerator 3 Ash pit 4 Ash melting equipment 5 Boiler 6 Exhaust gas treatment equipment 7 Crushing treatment 8 Saccharification treatment tank 9 Bioconversion treatment tank 10 Distillation process 11 Dehydration and drying treatment equipment

Claims (4)

  Mixing garbage with wood waste selectively collected from flammable waste carried into a waste incineration facility, saccharification treatment, biotransformation treatment and distillation to produce ethanol A method for producing ethanol in a waste incineration facility characterized by the above.   The method for producing ethanol in a waste incineration facility according to claim 1, wherein the mixing of the woody waste and the garbage is adjusted to a water content of 80 to 95% suitable for the saccharification treatment.   The ethanol production in the waste incineration facility according to claim 1 or 2, wherein the residual heat generated during the combustion of the waste in the waste incineration facility is used as a heat source for saccharification treatment, bioconversion treatment and distillation. Method.   Using the residual heat generated during the combustion of waste at a waste incineration facility, the residue after saccharification and bioconversion treatment is reduced to a moisture content that can be combusted, and incinerated at the waste incineration facility, and then the incineration ash is landfilled. The method for producing ethanol in a waste incineration facility according to claim 1, 2 or 3, characterized in that it is treated or recycled as various materials.

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