JP5631099B2 - Carbide manufacturing plant and carbide manufacturing method - Google Patents

Description

  The present invention relates to a carbide production plant and a carbide production method for producing carbide from biomass.

  2. Description of the Related Art A carbonization furnace is known in which biomass is pyrolyzed under the condition of blocking oxygen to generate carbides and pyrolysis gas. As the pyrolysis method, a pyrolysis rotating cylinder is heated from the outside, a heating pipe is provided in the pyrolysis rotating cylinder, and the heating pipe is heated by a burner built in the heating pipe, so that the radiant heat of the heating pipe is obtained. Conventionally, a method of heating biomass is known.

  A conventional carbide production plant will be described with reference to FIG. A conventional carbide production plant includes a dryer 110, a rotary kiln type carbonization furnace 120, a heating jacket 122 provided outside the carbonization furnace 120, a combustion furnace 130, a flue gas treatment tower 140, a chimney 150, The heat exchanger 160, the reheating furnace 170, the carbonization furnace heating gas flow path 191 that connects the combustion furnace 130 and the heating jacket 122 via the reheating furnace 170, and the combustion furnace 130 and the dryer 110 are connected. A dryer exhaust gas channel 192, a dry exhaust gas channel 193 connecting the dryer 110 and the combustion furnace 130 via a heat exchanger 160, and a combustion furnace 130 and a flue gas treatment tower 140 via a heat exchanger 160. And a discharge flow path 195 that connects the heating jacket 122 and the smoke treatment tower 140.

  The dryer 110 produces a dried product (dried sludge) as a pretreatment when carbonizing dehydrated sludge as an example of wet biomass. The carbonization furnace 120 pyrolyzes dry matter (dried sludge) under the condition of blocking oxygen to generate carbide and pyrolysis gas. The combustion furnace 130 burns the pyrolysis gas under a condition with an air ratio of 1 or more. Combustion furnace exhaust gas from the combustion furnace 130 passes through the carbonization furnace heating gas passage 191, the dryer heating gas passage 192, and the discharge passage 194, respectively, and the heating jacket 122, the dryer 110, and the flue gas treatment tower. 140. Here, the temperature of the combustion furnace exhaust gas at the outlet of the combustion furnace 130 is about 950 ° C. The memorial furnace 170 heats the combustion furnace exhaust gas supplied to the heating jacket 122 using an auxiliary fuel such as city gas. The heating jacket 122 indirectly heats the dry matter (dried sludge) in the carbonization furnace 120 using the combustion furnace exhaust gas. Here, in order to heat the inside of the carbonization furnace 120 to about 600 ° C. necessary for pyrolysis, a combustion furnace exhaust gas of about 1100 ° C. is required. The combustion furnace exhaust gas discharged from the heating jacket 122 is supplied to the smoke processing tower 140 via the discharge flow path 195. Here, an air preheater (not shown) preheats the combustion air introduced into the combustion furnace 130 using the heat of the combustion furnace exhaust gas in the discharge passage 195. The combustion furnace exhaust gas supplied to the dryer 110 is used to dry the dewatered sludge, and is discharged as a dry exhaust gas containing moisture and odor components from the dehydrated sludge. The dried exhaust gas is returned to the combustion furnace 130 via the dried exhaust gas channel 193. The dried exhaust gas is processed in the combustion furnace 130. The heat exchanger 160 performs heat exchange between the dry exhaust gas in the dry exhaust gas passage 193 and the combustion furnace exhaust gas in the exhaust passage 194. Thereby, heat is recovered from the combustion furnace exhaust gas in the discharge passage 194 and returned to the combustion furnace 130. The flue gas treatment tower 140 performs flue gas treatment on the combustion furnace exhaust gas. The combustion furnace exhaust gas that has been subjected to the flue gas treatment is discharged from the chimney 150 into the atmosphere.

  The combustion furnace exhaust gas discharged from the combustion furnace 130 has a sufficient temperature as a heat source for the dryer 110, but the temperature is insufficient as a heat source for the carbonization furnace 120. Therefore, the combustion furnace exhaust gas supplied to the heating jacket 122 is heated by the remedy furnace 170. Further, since the temperature of the combustion furnace exhaust gas in the heating jacket 122 decreases due to the air leaking from the gap between the carbonization furnace 120 and the heating jacket 122, the combustion furnace exhaust gas supplied to the heating jacket 122 in consideration of this temperature decrease. Needs to be heated by the memory furnace 170. For this reason, the amount of auxiliary fuel used in the remedy furnace 170 is large, and it is required to reduce the amount of auxiliary fuel used in the carbide manufacturing plant.

  Patent Document 1 introduces a pyrolysis gas discharged from a thermal decomposition rotary cylinder that thermally decomposes organic waste into a reforming heating tube provided in a gas reforming chamber, The pyrolysis gas is converted into reformed gas by heating from the outside with a reforming burner, and the reformed gas is introduced into the pyrolysis heating tube provided in the thermal decomposition rotating cylinder, An organic waste thermal decomposition apparatus that decomposes organic waste by radiant heat is disclosed.

JP 2003-320359 A

  An object of the present invention is to provide a carbide manufacturing plant and a carbide manufacturing method in which the amount of auxiliary fuel used is reduced.

  The means for solving the problem will be described below using the numbers used in the (DETAILED DESCRIPTION). These numbers are added to clarify the correspondence between the description of (Claims) and (Mode for Carrying Out the Invention). However, these numbers should not be used to interpret the technical scope of the invention described in (Claims).

  A carbide production plant according to the present invention includes a rotary kiln type carbonization furnace (20) that pyrolyzes biomass to produce carbides and pyrolysis gas, and a partial combustion gas obtained by burning the pyrolysis gas under an air ratio of less than 1. A partial combustion reactor (70) for generating the carbonization furnace, a heating jacket (22) for heating the carbonization furnace, a combustion furnace (30) for burning the partial combustion gas under an air ratio of 1 or more, and the heating jacket And a partial combustion gas flow path (91) for connecting the partial combustion reactor and the combustion furnace.

  The carbide manufacturing plant includes a dryer (10) for drying wet biomass before drying using the combustion furnace exhaust gas from the combustion furnace, and a dry exhaust gas flow path for returning the dried exhaust gas from the dryer to the combustion furnace. (93).

  The method for producing carbide according to the present invention includes a step of pyrolyzing biomass in a rotary kiln type carbonization furnace (20) to produce carbide and pyrolysis gas, and burning the pyrolysis gas under a condition with an air ratio of less than 1. Generating a partial combustion gas, supplying the partial combustion gas to a combustion furnace (30) via a heating jacket (22), heating the carbonization furnace by the heating jacket, and the combustion furnace Combusting the partial combustion gas under a condition where the air ratio is 1 or more.

  In the carbide manufacturing method, the dryer (10) uses the combustion exhaust gas from the combustion furnace to dry the wet biomass before drying to produce a dried product, and the combustion of the dry exhaust gas from the dryer Returning to the furnace.

  ADVANTAGE OF THE INVENTION According to this invention, the carbide manufacturing plant and carbide manufacturing method in which the usage-amount of auxiliary fuel are reduced are provided.

FIG. 1 is a block diagram of a conventional carbide production plant. FIG. 2 is a block diagram of a carbide production plant according to the first embodiment of the present invention.

  With reference to an accompanying drawing, a form for carrying out a carbide manufacturing plant and a carbide manufacturing method by the present invention is explained below.

(First embodiment)
With reference to FIG. 2, the carbide manufacturing plant which concerns on the 1st Embodiment of this invention is demonstrated. The carbide production plant includes a dryer 10, a rotary kiln type carbonization furnace 20, a heating jacket 22 provided outside the carbonization furnace 20, a combustion furnace 30, a flue gas treatment tower 40, a chimney 50, and heat exchange. , A partial combustion gas flow path 91 that connects the partial combustion reactor 70 and the combustion furnace 30 via the heating jacket 22, and a drying that connects the combustion furnace 30 and the dryer 10. A heating gas flow path 92, a dry exhaust gas flow path 93 connecting the dryer 10 and the combustion furnace 30 via the heat exchanger 60, a dryer 10 and the flue gas treatment tower 40 via the heat exchanger 160, And a discharge channel 94 for connecting the two.

  A carbide manufacturing method using the carbide manufacturing plant according to the first embodiment will be described. The dryer 10 dries dehydrated sludge as an example of wet biomass to produce a dried product (dried sludge). The carbonization furnace 20 pyrolyzes dry matter (dried sludge) under the condition of blocking oxygen to generate carbide and pyrolysis gas. Carbides are used as an alternative fuel for fossil fuels. The partial combustion reactor 70 partially burns the pyrolysis gas to generate a partial combustion gas. Since the partial combustion reactor 70 burns the pyrolysis gas under the condition that the air ratio is less than 1, the partial combustion gas contains a combustible component. Here, the amount of air introduced into the partial combustion reactor 70 is adjusted so that the temperature of the partial combustion gas becomes about 1100 ° C. necessary for heating the carbonization furnace 20. The partial combustion gas is supplied to the heating jacket 22 via the partial combustion gas passage 91. The heating jacket 22 indirectly heats the dry matter (dried sludge) in the carbonization furnace 20 using the partial combustion gas. The partial combustion gas discharged from the heating jacket 22 is supplied to the combustion furnace 30 via the partial combustion gas passage 91. The combustion furnace 30 completely burns the partial combustion gas under the condition where the air ratio is 1 or more. Combustion furnace exhaust gas from the combustion furnace 30 is supplied to the dryer 10 and the flue gas treatment tower 40 via the dryer heating gas passage 92 and the discharge passage 94, respectively. The combustion furnace exhaust gas supplied to the dryer 10 is used for drying the dehydrated sludge, and is discharged as a dry exhaust gas containing moisture and odor components from the dehydrated sludge. The dried exhaust gas is returned to the combustion furnace 30 via the dried exhaust gas channel 93. The dried exhaust gas is processed in the combustion furnace 30. The heat exchanger 60 exchanges heat between the dry exhaust gas in the dry exhaust gas passage 93 and the combustion furnace exhaust gas in the exhaust passage 94. Thereby, heat is recovered from the combustion furnace exhaust gas in the discharge passage 94 and returned to the combustion furnace 30. The flue gas treatment tower 40 performs flue gas treatment on the combustion furnace exhaust gas. Combustion furnace exhaust gas that has been subjected to the flue gas treatment is discharged from the chimney 50 into the atmosphere.

  According to this embodiment, since the carbonization furnace 20 is heated using the partial combustion gas obtained by partial combustion of the pyrolysis gas generated in the carbonization furnace 20, the remedy furnace 70 shown in FIG. The amount of usage is reduced. Further, even if air leaks from the gap between the carbonization furnace 20 and the heating jacket 22, the partial combustion gas in the heating jacket 22 is caused by an exothermic reaction between oxygen contained in the air and combustible components contained in the partial combustion gas. Temperature drop is prevented.

  The partial combustion gas supplied to the heating jacket 22 has a larger specific heat Cp than the combustion furnace exhaust gas supplied to the heating jacket 122 of FIG. Therefore, the carbonization furnace 20 is efficiently heated from the partial combustion gas.

  In the partial combustion reactor 70, since the pyrolysis gas is partially burned, the temperature is higher than that in the carbonization furnace 20, so that the tar content contained in the pyrolysis gas is decomposed and introduced into the partial combustion reactor 70. Diluted with air. Therefore, it is possible to prevent tar trouble from occurring in the partial combustion gas passage 91.

  In the carbide manufacturing plant shown in FIG. 1, it is necessary to provide a fan (not shown) for attracting combustion furnace exhaust gas from the combustion furnace 130 via the heating jacket 122 in the exhaust passage 195. In this embodiment, No such fan is needed.

  In this embodiment, other high water content wet biomass may be used instead of dehydrated sludge. For example, agricultural waste may be used.

  The carbide production plant and the carbide production method according to the present embodiment can be applied to a process for producing carbide from woody biomass having a low water content. In this case, the dryer 10 is unnecessary, and the woody biomass is directly fed into the carbonization furnace 20. Further, it is possible to generate power by providing a power generation boiler instead of the combustion furnace 30.

  The present invention is not limited to the above embodiment. For example, the temperature condition can be changed as necessary. Further, steam may be introduced into the partial combustion reactor 70.

DESCRIPTION OF SYMBOLS 10 ... Dryer 20 ... Carbonization furnace 22 ... Heating jacket 30 ... Combustion furnace 40 ... Smoke treatment tower 50 ... Chimney 60 ... Heat exchanger 70 ... Partial combustion reactor 91 ... Partial combustion gas flow path 92 ... Dryer heating gas flow Channel 93 ... Dry exhaust gas channel 94 ... Discharge channel 110 ... Dryer 120 ... Carbonization furnace 122 ... Heating jacket 130 ... Combustion furnace 140 ... Smoke treatment tower 150 ... Chimney 160 ... Heat exchanger 170 ... Remembrance furnace 191 ... Carbonization Furnace heating gas channel 192 ... Dryer heating gas channel 193 ... Dry exhaust gas channel 194,195 ... Discharge channel

Claims (4)

A rotary kiln type carbonization furnace that pyrolyzes biomass to produce carbides and pyrolysis gas;
A partial combustion reactor that generates the partial combustion gas by burning the pyrolysis gas under an air ratio of less than 1;
A heating jacket for heating the carbonization furnace;
A combustion furnace that burns the partial combustion gas under an air ratio of 1 or more;
A carbide manufacturing plant comprising a partial combustion gas flow path connecting the partial combustion reactor and the combustion furnace via the heating jacket. A dryer for drying the biomass before drying using the combustion furnace exhaust gas from the combustion furnace to produce a dried product;
The carbide production plant according to claim 1, further comprising a dry exhaust gas passage for returning the dry exhaust gas from the dryer to the combustion furnace. Pyrolyzing biomass in a rotary kiln type carbonization furnace to produce carbides and pyrolysis gas;
Combusting the pyrolysis gas under conditions with an air ratio of less than 1 to generate a partial combustion gas;
Supplying the partial combustion gas to the combustion furnace via a heating jacket;
The heating jacket heating the carbonization furnace;
A combustion furnace comprising: burning the partial combustion gas under a condition where the combustion furnace has an air ratio of 1 or more. Drying a biomass before drying using a flue gas from the combustion furnace to produce a dried product;
The method for producing carbide according to claim 3, further comprising a step of returning the dried exhaust gas from the dryer to the combustion furnace.

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