JP4899484B2 - Organic matter processing method and processing apparatus - Google Patents

Description

The present invention relates to an organic matter processing method and a processing apparatus for effectively using organic matter, particularly waste containing the organic matter as fuel.

In general, waste is often simply incinerated or landfilled. In recent years, attempts have been made to effectively use waste containing organic matter as a substitute for fossil fuel. For example, Patent Document 1 describes a method in which a carbonization gas obtained by carbonizing combustible waste is used as a fuel for calcining cement raw materials.
JP-A-11-292580

  However, when processing waste containing organic matter containing a lot of moisture and impurities, stable operation of equipment used as fuel may be hindered. In addition, tar, which is a viscous liquid organic substance generated during dry distillation, may cause problems such as blockage of piping and contamination of downstream equipment.

An object of the present invention is to solve the above-described problems of the prior art and to provide an industrially excellent organic matter treatment method and treatment equipment for stably treating waste containing a large amount of organic matter. To do.

The present invention heats an organic substance to obtain a carbide and a generated gas, the generated gas performs partial combustion, and supplies the carbide and a combustible gas obtained by the partial combustion to a combustion facility. It is a processing method.
In addition, a carbonization furnace for carbonizing organic substances, a partial combustion furnace for partial combustion of the gas generated in the carbonization furnace, a carbide generated in the carbonization furnace and a combustible gas generated in the partial combustion furnace are used as fuel. An organic matter processing apparatus provided with a combustion facility.

  According to the present invention, it is possible to obtain a fuel with a reduced volatile content and an improved fixed carbon content. Further, tar and hydrogen chloride can be effectively treated. This makes it possible to stably and effectively use a large amount of waste containing organic matter as a substitute for fossil fuel without hindering stable operation of the combustion facility.

Examples of the organic material used in the present invention include thinned wood, wood waste in construction waste, biomass such as coffee cake and teacup, waste plastics containing polyethylene, polyethylene terephthalate, and the like, and various mixtures thereof. The organic substance may contain an inorganic substance.
When foreign substances such as metals are mixed in the organic matter, it is preferable to remove the foreign substances with a magnetic separator or the like in advance. Moreover, when there is much content of the water | moisture content of organic substance, it is preferable to dry previously.
The size of the organic substance is 100 mm or less, preferably 50 mm or less under the sieve. When the organic matter is large, it is preferable to crush in advance with a crusher.
By the above, the to-be-processed object which does not cause a driving | operation failure in a post process can be obtained.

Next, the process of heating the organic material will be described. The heating temperature is 200 to 600 ° C, preferably 300 to 500 ° C, more preferably 400 to 500 ° C. The heating time is 30 to 120 minutes, preferably 60 to 90 minutes. Furthermore, the oxygen concentration in the heating atmosphere is 10% by volume or less, preferably 1% by volume or less. As a result, carbide and generated gas are obtained.
Here, the carbide | carbonized_material in this invention means the solid substance whose ratio of the fixed carbon obtained by heating is higher than the organic substance before carbonization. For example, the volatile matter contained in the organic substance before carbonization is reduced to 1/10 to 1/2 on a weight basis, and the fixed carbon is increased 2 to 4 times on a weight basis. Examples of the composition of the carbide include carbon containing 5 to 90% by weight, hydrogen 0.1 to 5.0% by weight, and oxygen 5 to 20% by weight.
The generated gas refers to a combustible gas containing hydrogen, carbon monoxide, hydrocarbons, and the like. For example, hydrogen is 1 to 10% by volume, carbon monoxide is 1 to 20% by volume, carbon dioxide is 1 to 40% by volume, methane is 5 to 20% by volume, and other hydrocarbons having 2 or more carbon atoms and water vapor. A mixed gas is mentioned.
By the above, the alternative fuel of coal or natural gas can be obtained.

Next, partial combustion of the generated gas obtained by heating is performed. The partial combustion referred to in the present invention means that the combustible is burned with an oxygen amount equal to or less than the theoretical oxygen amount. The temperature of partial combustion is 800 ° C. or higher, preferably 1,000 ° C. or higher. The gas for partial combustion includes a gas containing oxygen. Specific examples include pure oxygen, air, carbon dioxide, and nitrogen mixed with oxygen. Furthermore, it is also possible to use high temperature gas generated in a combustion facility described later. The oxygen concentration in the partial combustion atmosphere is controlled to 0.1% by volume or less. The residence time of the generated gas is 3 to 5 seconds.
By partial combustion, tars composed of aromatics such as toluene and naphthalene, higher paraffins, higher olefins, higher naphthenes and the like are decomposed, and a clean combustible gas containing hydrogen, carbon monoxide, methane and the like can be obtained. The composition of the combustible gas is 20 to 25% by volume of hydrogen, 10 to 20% by volume of carbon monoxide, 5 to 10% by volume of carbon dioxide, 1 to 10% by volume of methane, 1 to 40% by volume of nitrogen, The mixed gas which water vapor | steam consists of 20-40 volume% is mentioned. The combustible gas after partial combustion is rapidly cooled from 1100 ° C. to, for example, 110 ° C. with water.

Next, the combustible gas obtained by carbide and partial combustion is supplied to a combustion facility. The combustion facility used in the present invention is a facility that conventionally uses coal as fuel. Specific examples of the combustion equipment include at least one of cement production equipment, power generation equipment, and gasification equipment. For example, in a cement manufacturing facility, carbides and combustible gas are supplied to a rotary kiln before a kiln or to a calcining furnace.
At that time, it is preferable that the carbide is mixed and pulverized in advance with the coal previously supplied to the kiln of the rotary kiln or the calcining furnace and supplied to the kiln of the rotary kiln or the calcining furnace.
On the other hand, the combustible gas is preferably mixed with the clinker cooler extraction gas supplied to the calcining furnace and supplied to the calcining furnace. When a part of coal is replaced with carbide, the supply ratio of coal and carbide is about 10 to 1 by weight.

Before supplying the combustible gas obtained by partial combustion to a combustion facility, it is preferable to wash with alkaline water in advance. Thereby, unburned carbon contained in combustible gas is collected. Moreover, it can neutralize acidic gas components, such as hydrogen chloride gas contained in combustible gas, and can collect | recover as chloride. Moreover, corrosion of the combustion facility by acid gas can be prevented. Examples of the alkaline water include a caustic soda aqueous solution and ammonia water. The cleaning liquid is repeatedly used by circulating. The contact time between the combustible gas and the alkaline aqueous solution is about 5 seconds. The temperature of the combustible gas after washing with alkaline water is 90 to 110 ° C.

Thereafter, a small amount of tar mist accompanying the combustible gas after washing with alkaline water is removed. A demister is mentioned as a method for removing tar mist. As a result, it is possible to prevent clogging of equipment and piping due to tar, which can contribute to stable operation.

The washing liquid after washing the combustible gas with alkaline water is subjected to solid-liquid separation. The temperature of solid-liquid separation is the atmospheric temperature. When the temperature of the cleaning liquid is high, the cleaning liquid is cooled in advance by a shell-and-tube heat exchanger before being supplied to the solid-liquid separator. The residence time for solid-liquid separation is about 120 minutes. The solid content including fine carbide, soot, metal hydroxide and the like after the solid-liquid separation is supplied to the combustion facility. As a result, the solid content can be further effectively used as combustion. The solids are preferably freed of entrained water by a centrifuge or filter before being supplied to the combustion facility. Further, the solid content can be mixed with coal before being supplied to the combustion facility, and can be supplied to the combustion facility by a supply means such as a slurry pump or a conveyor.

On the other hand, the liquid phase after solid-liquid separation is circulated and used as washing water for washing the combustible gas obtained by the partial combustion, and a part thereof is subjected to filtration, activated carbon treatment, and heavy metal treatment. The

The accompanying noncombustible material is removed from the carbide obtained by heating the organic material. Examples of the method for removing incombustible materials include a vibrating sieve, a magnetic separator, and a non-ferrous metal removing device. The carbide after the incombustible material is removed is supplied to the combustion facility. Thereby, it becomes possible to perform stable operation of the combustion facility without introducing foreign matter into the combustion facility.

The incombustible material removed from the carbide is preferably washed. Examples of the cleaning method include a method of immersing an incombustible material in water and a method of showering water from the top of the incombustible material. Thereby, the carbide | carbonized_material adhering to the incombustible substance can be collect | recovered effectively. The cleaning liquid containing carbide is supplied to the above-described solid-liquid separator. The solid content after the solid-liquid separation is supplied to the combustion facility. On the other hand, the incombustible matter after being washed is treated as industrial waste.

The high-temperature gas of 300 to 800 ° C. generated in the combustion facility can be used as a heating source for heating organic substances to obtain carbide and generated gas, and as a gas source or heating source for partial combustion. Specific examples of the high temperature gas generated in the combustion facility include clinker cooler outlet exhaust gas (300 to 800 ° C.), cyclone preheater exhaust gas (300 to 400 ° C.) and the like in the cement manufacturing apparatus. The kind, temperature and supply amount of the hot gas are appropriately selected according to the desired temperature in carbonization and partial combustion. When using as a heating source for heating organic matter, an indirect heating method is preferred.

In partial combustion, in order to obtain a high calorie combustible gas having a calorific value of 6.3 MJ / Nm3 or more, oxygen is used as a partial combustion gas, and a high-temperature gas generated in a combustion facility is used as a heating source for the oxygen. . On the other hand, in order to obtain a low-calorie combustible gas having a calorific value of less than 6.3 MJ / Nm3, a high-temperature gas can be used as it is as a partial combustion gas. The hot gas used as an indirect heating source for heating the organic matter is recovered again in the combustion facility. Thereby, thermal efficiency can be further improved in the whole series of systems from carbonization to combustion facilities.

Next, the organic substance processing apparatus will be described. As a carbonization furnace for obtaining a carbide and generated gas by heating an organic substance, a rotary carbonization furnace can be mentioned. The carbonization furnace has a supply port for supplying organic substances on both sides thereof, and an exhaust port for discharging carbide and generated gas. The organic matter is gradually heated in the carbonization furnace and thermally decomposed at a predetermined temperature. Moreover, the carbonization furnace is of a jacket type and has a supply port and a discharge port to which high-temperature gas from the combustion facility is supplied for indirect heating as described above. The organic substance and the high-temperature gas for indirect heating are transferred by countercurrent. That is, the organic substance supply side and the high temperature gas discharge side, the carbide and generated gas discharge side, and the high temperature gas supply port are arranged in the vicinity.

Next, a partial combustion furnace for partially burning generated gas generated in a carbonization furnace will be described. The partial combustion furnace includes a supply port for supplying generated gas to the partial combustion furnace, a supply port for supplying partial combustion gas, and an exhaust port for discharging combustible gas after partial combustion. . A supply port for supplying the generated gas to the partial combustion furnace is provided at the upper part or the top of the side face of the partial combustion furnace. When the supply port is on the upper side of the partial combustion furnace, the generated gas forms a swirling flow in the partial combustion furnace. On the other hand, when the supply port is the top of the partial combustion furnace, the generated gas is jetted vertically downward in the partial combustion furnace.
A supply port for supplying the partial combustion gas is provided on the side of the partial combustion furnace. The partial combustion gas forms a swirl flow in the partial combustion furnace. A plurality of supply ports for supplying the partial combustion gas can be provided in the vertical direction. Thereby, as a result of dispensing the partial combustion gas, good contact between the generated gas and the partial combustion gas can be achieved.

The combustible gas obtained in the partial combustion furnace and the carbide obtained in the carbonization furnace are used as fuel in the combustion facility. Specific examples of the combustion equipment include at least one of cement production equipment, power generation equipment, and gasification equipment.

The combustible gas obtained in the partial combustion furnace can be introduced into a quenching pot in which water is stored and cooled before being supplied to the combustion facility. The quenching pot includes a supply port for supplying the combustible gas to the quenching pot, a discharge port for discharging the combustible gas after cooling, and a discharge port for discharging the cooling water and using it in a circulating manner. A discharge port for combustible gas from the partial combustion furnace and a supply port for the quenching pot are connected by a connecting pipe. The inner wall of the connecting pipe is a wet wall, preventing the inner wall of the connecting pipe from becoming abnormally hot. The tip of the connecting pipe is directly immersed in the water stored in the quenching pot.
The discharge port for discharging the combustible gas after cooling is provided above the water surface of the quenching pot. Thereby, the combustible gas from a partial combustion furnace is rapidly cooled by contacting with water directly. The rapidly cooled combustible gas is guided to the cleaning tower in the next process.

A spray tower is mentioned as a washing tower for washing combustible gas. The cleaning tower uses a supply port for supplying flammable gas, a discharge port for discharging flammable gas after cleaning, a supply port for spraying cleaning liquid, and discharging and circulating the cleaning liquid. It consists of an outlet for. Spray nozzles are provided in multiple stages on the side of the washing tower. Moreover, the discharge port for discharging | emitting the combustible gas after washing | cleaning is provided in the top part of the washing tower. The combustible gas is brought into countercurrent contact with the alkaline water supplied from the spray nozzle. This supplements unburned carbon and hydrogen chloride contained in the combustible gas. The cleaning liquid is discharged from a discharge port provided at the bottom of the cleaning tower. A part of the discharged cleaning liquid is supplied to the solid-liquid separator, and the rest is circulated and used for the spray nozzle.

A removal apparatus for removing tar mist accompanying the combustible gas after cleaning will be described. A side surface of the cylindrical tank has a supply port for supplying the cleaned gas. A baffle plate is provided at the supply port, and the structure prevents the gas from short-passing.
In the upper part of the tank, a demister for removing tar mist is arranged. A gas outlet is provided at the top of the tank. An outlet for discharging tar mist is provided at the bottom of the tank. The discharge port and the washing tower are connected by piping, and tar is returned to the washing tower.

An example of the solid-liquid separation device for solid-liquid separation of the washing liquid discharged from the washing tower is a thickener. An overflow pipe for overflowing the liquid phase is provided on the upper side surface. The bottom is provided with a discharge port for discharging the solid content. The extracted solid content is supplied to the combustion facility. The solid content extracted by the solid-liquid separator is supplied to a centrifuge or a filter by an extraction pump before being supplied to the combustion facility, so that the water content of the solid content can be further removed.

Next, the carbide obtained in the carbonization furnace can be supplied to the incombustible material removal device before being supplied to the combustion facility. Examples of the incombustible material removal device include a vibration sieve, a magnetic separator, and a non-ferrous metal removal device. Incombustible materials such as iron and aluminum are removed in the incombustible material removal device. In addition, the carbide | carbonized_material discharged | emitted from the carbonization furnace before supplying to an incombustible substance removal apparatus can also be cooled with a carbide cooler. An indirect cooling type is mentioned as a carbide cooler.

The incombustible material removed by the incombustible material removing device is supplied to the cleaning device, and the carbide adhering to the surface of the incombustible material can be recovered together with the cleaning liquid. Examples of the cleaning device include a tank equipped with a stirrer that stores water, and a device that sprays water uniformly from above on carbides stored in a tray. The cleaning liquid containing the carbide is sent to the above-described solid-liquid separator by a pump.

  INDUSTRIAL APPLICABILITY The present invention can be used when waste containing organic matter is effectively used as an alternative fuel for coal.

Claims (11)

An organic matter is heated to obtain a carbide and a generated gas, the generated gas is subjected to partial combustion, and the carbide and the combustible gas obtained by the partial combustion are supplied to a combustion facility, and the organic matter is treated.
The combustible gas is washed with alkaline water and supplied to the combustion facility,
Supplying the cleaning liquid after washing with alkaline water to the solid-liquid separator, supplying the solid content after solid-liquid separation to the combustion facility ,
Supplying carbide to the combustion facility after removing incombustibles accompanying the carbide,
A method for treating an organic material , comprising: cleaning the removed incombustible material and supplying the cleaning liquid to the solid-liquid separator . 2. The organic matter processing method according to claim 1, wherein the combustion facility is at least one of a cement production facility, a power generation facility, and a gasification facility. The organic matter processing method according to claim 1 or 2, wherein tar mist accompanying the combustible gas after washing with the alkaline water is removed.   The organic substance processing method according to any one of claims 1 to 3, wherein a high-temperature gas generated in the combustion facility is used as a heating source for the organic substance.   The organic substance processing method according to any one of claims 1 to 4, wherein a high-temperature gas generated in the combustion facility is used as the partial combustion gas.   The method for treating organic matter according to any one of claims 1 to 5, wherein the organic matter is biomass, waste plastic, or a mixture thereof.   The cleaning liquid after cleaning with the alkaline water is supplied to the solid-liquid separator, and the liquid phase after solid-liquid separation is used as cleaning water for cleaning the combustible gas. The processing method of the organic substance of any one of Claims 1.   The method for treating an organic material according to any one of claims 2 to 7, wherein the cement manufacturing facility is a kiln in a rotary kiln or a calcining furnace.   The organic material processing method according to claim 8, wherein the carbide is supplied to a kiln of the rotary kiln or to a calcining furnace, and the combustible gas is supplied to the calcining furnace.   Carbonization furnace for carbonizing organic substances, partial combustion furnace for partial combustion of the gas generated in the carbonization furnace, combustion using carbide generated in the carbonization furnace and combustible gas generated in the partial combustion furnace as fuel Equipment,
A washing tower for washing the combustible gas with alkaline water;
A solid-liquid separation device for solid-liquid separation of the processing liquid discharged from the washing tower, and a supply means for supplying solid content to the combustion facility;
With
  A non-combustible material removing device for removing non-combustible material accompanying the carbide, a cleaning device for cleaning the non-combustible material, and a supply means for supplying a cleaning liquid to the solid-liquid separator.
An organic matter processing apparatus.   The organic substance processing apparatus according to claim 10, further comprising a removing device for removing tar mist accompanying the combustible gas after washing.