JP2018115307A - Method and system for serial semi-carbonization for biomass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a uniform quality semi-carbide with higher energy utilization efficiency by semi-carbonizing a biomass under shutting off an air at a temperature of 400°C or lower.SOLUTION: Serial semi-carbonization method for a biomass of the present invention comprises a first semi-carbonization process for raising the temperature of a biomass from an ordinary temperature up to approximately 250-300°C by heating under shutting off an air; a second semi-carbonization process for semi-carbonizing a discharged biomass from the first semi-carbonization process by holding under shutting off an air at approximately 250-300°C for approximately 30 minutes to 4 hours; a cooling process for cooling and recovering a semi-carbide discharged from the second semi-carbonization process; a combustion process for burning a pyrolysis gas generated from the first semi-carbonization process and a pyrolysis gas generated from the second semi-carbonization process; and a heat-utilization process for utilizing a heat generated from the combustion process both in the first and second semi-carbonization processes.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a two-connected semi-carbonizing method for biomass and a two-connected semi-carbonizing system for biomass.

In order to use woody biomass as energy, the woody biomass has the disadvantage that the calorific value per unit weight is low and the disadvantage that it is difficult to grind with fiber.
As is widely known, carbonization of woody biomass makes it easier to use energy. For example, it has been widely practiced to make charcoal by putting woody biomass in a kiln and steaming at 400 ° C to 1000 ° C.

When the woody biomass is carbonized at 400 ° C. or lower with the air blocked by indirect heating, the energy density is improved and the pulverization characteristics are improved.
Carbonizing woody biomass at 400 ° C. or lower with air blocked by indirect heating is referred to as semi-carbonization. The product by semi-carbonization is called semi-carbide.

Problems to be solved by the invention

The woody biomass immediately after being cut contains 50% or more moisture. Woody biomass dried in the air contains about 20% moisture.
When the storage state or the like changes, the amount of water contained in the woody biomass changes.

According to the conventional semi-carbonization method, the semi-carbonization temperature is 350 ° C. to 400 ° C., and the time from the start of temperature rise to the end of semi-carbonization is about 30 minutes or less.
Since it takes time for the water contained in the woody biomass to evaporate and the woody biomass temperature to rise to the half carbonization temperature, the half carbonization time is about 15 minutes or less.

When the semi-carbonization time is about 15 minutes or less, even if the semi-carbonization temperature changes slightly, the semi-carbide characteristics change greatly. For example, when cedar is semi-carbonized at a semi-carbonization temperature of 350 ° C. and a semi-carbonization time of about 15 minutes, when the semi-carbonization temperature increases by 1 ° C., the ratio of the weight of the semi-carbide to the cedar weight (residual weight ratio) is 0.5. Decrease by more than%.
According to the conventional semi-carbonization method, the semi-carbonization temperature has to be precisely controlled in order to produce a homogeneous semi-carbide.

A large amount of heat is required to evaporate the water contained in the woody biomass.
The water content varies depending on the storage state of woody biomass. If the moisture content varies, the amount of heat necessary to evaporate the moisture contained in the woody biomass also varies.

According to the conventional semi-carbonization method, in order to evaporate the water contained in the woody biomass, a large amount of heat must be supplied, and the amount of heat supplied must be controlled in accordance with fluctuations in the moisture content of the woody biomass.
If the amount of heat supplied is greater than the amount of heat required to evaporate the moisture contained in the woody biomass, the semi-carbonization temperature will rise and supply more than the amount of heat required to evaporate the water contained in the woody biomass. If the amount of heat is small, the semi-carbonization temperature decreases.
It is difficult to precisely control the semi-carbonization temperature by precisely controlling the amount of heat supplied in accordance with fluctuations in the moisture content of the woody biomass.

  According to the conventional semi-carbonization method, there is a problem that it is difficult to precisely control the semi-carbonization temperature even though the semi-carbonization temperature must be precisely controlled.

  According to the two-connected semi-carbonization method for biomass according to the first aspect of the present invention, the woody biomass is held at 250 ° C. to 300 ° C., the water in the woody biomass is evaporated, and the woody biomass temperature is increased. The first semi-carbonization step of raising the temperature to 250 ° C. to 300 ° C. and the woody biomass discharged from the first semi-carbonization step at 250 ° C. to 300 ° C. for 30 minutes to 4 hours, A second semi-carbonizing step.

  According to the two-connected semi-carbonization system for biomass according to the second aspect of the present invention, the woody biomass is retained at 250 ° C. to 300 ° C. to evaporate water in the woody biomass, Hold the woody biomass discharged from the first half carbonization process and the first half carbonization step at 250 ° C to 300 ° C at 250 ° C to 300 ° C for 30 minutes to 4 hours to obtain woody biomass A second semi-carbonizing device for semi-carbonizing.

An external heating rotary kiln, an external heating screw conveyor, or the like may be used for the first semi-carbonizing device.
You may use an external heating type rotary kiln, an external heating type screw conveyor, etc. for a 2nd semi-carbonization apparatus.

  According to the two-connected semi-carbonization method for biomass according to the first aspect of the present invention, the first amount that requires a large amount of heat to evaporate water contained in the woody biomass and raise the temperature of the woody biomass. By separating the semi-carbonization process and the second semi-carbonization process that requires precise control of the semi-carbonization temperature, the semi-carbonization temperature of the woody biomass in the second semi-carbonization process can be precisely controlled.

  According to the two-connected semi-carbonization system for biomass according to the second aspect of the present invention, the first amount that requires a large amount of heat to evaporate the moisture contained in the woody biomass and raise the temperature of the woody biomass. By separating the semi-carbonizing device from the second semi-carbonizing device that requires precise control of the semi-carbonizing temperature, the semi-carbonizing temperature of the woody biomass in the second semi-carbonizing device can be precisely controlled.

(Semi-carbide properties can be controlled by controlling the semi-carbonization time)
The inventors have the same characteristics as the semi-carbides obtained by the conventional semi-carbonization method when semi-carbonizing woody biomass at a semi-carbonization temperature of 250 ° C. to 300 ° C. and a semi-carbonization time of 30 minutes to 4 hours. It has been found that semi-carbides can be produced.
Inventors can control the characteristics of semi-carbides by controlling the semi-carbonization time when wood carbon is semi-carbonized at a semi-carbonization temperature of 250 ° C to 300 ° C and a semi-carbonization time of 30 minutes to 4 hours. I found.
Table 2 shows the semi-carbonization time and the residual weight ratio when the cedar wood part is semi-carbonized at 250 ° C to 300 ° C.

  Control of the semi-carbonization time is easy. For example, in the case of an external heat type rotary kiln, the semi-carbonization time can be easily controlled by adjusting the rotation speed of the inner cylinder. For example, in the case of an externally heated screw conveyor, the semi-carbonization time can be easily controlled by adjusting the speed of the screw conveyor.

[High energy use efficiency]
Heat flows from the hot part to the cold part. The amount of heat flowing is proportional to the temperature difference between the high temperature part and the low temperature part.
In an externally heated rotary kiln or an externally heated screw conveyor, the amount of heat available for semi-carbonization is proportional to the temperature difference between the combustion gas temperature and the semi-carbonized temperature.
According to the method of the present invention, the amount of heat that is higher than the amount of heat available for semi-carbonization in the conventional semi-carbonization method by semi-carbonizing at a semi-carbonization temperature of 250 ° C. to 300 ° C., lower than the conventional semi-carbonization temperature. Available for semi-carbonization. Therefore, energy use efficiency is high.

[Easy control of semi-carbonization temperature]
The inventors have found that when the semi-carbonization temperature is low, the carbide properties do not change much even if the semi-carbonization temperature changes.
For example, when semi-carbonizing cedar with a semi-carbonization temperature of 250 ° C. and a semi-carbonization time of about 15 minutes, if the semi-carbonization temperature changes by 1 ° C., the residual weight ratio changes by about 0.06%. On the other hand, as described above, when semi-carbonizing cedar with a semi-carbonizing temperature of 350 ° C. and a semi-carbonizing time of about 15 minutes, when the semi-carbonizing temperature rises by 1 ° C., the residual weight ratio decreases by 0.5% or more.
According to the conventional semi-carbonization method, the semi-carbonization temperature must be precisely controlled at a semi-carbonization temperature of 350 ° C. to 400 ° C. and a semi-carbonization time of about 15 minutes or less.
According to the two-connected semi-carbonization method for biomass of the present invention, the semi-carbonization temperature is 250 ° C. to 300 ° C., the semi-carbonization time is 30 minutes to 4 hours, and precise control of the semi-carbonization temperature is unnecessary.

  According to the two-connected semi-carbonization method for biomass according to the first aspect of the present invention, the semi-carbonization temperature is 250 ° C. to 300 ° C., the semi-carbonization time is 30 minutes to 4 hours, the energy is used efficiently, and the characteristics are uniform. Carbide can be easily obtained.

  According to the two-connected semi-carbonization system for biomass according to the second aspect of the present invention, the semi-carbonization temperature is 250 ° C. to 300 ° C., the semi-carbonization time is 30 minutes to 4 hours, the energy utilization efficiency is high, and the characteristics are uniform. Carbide can be easily obtained.

[First embodiment]
Hereinafter, the two-linked carbonization method for biomass according to the first embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the two-connected semi-carbonization method 1 for biomass according to the present embodiment evaporates water contained in the woody biomass 2 and raises the woody biomass 2 to a semi-carbonization temperature. 3, a connecting step 7 for circulating the pyrolysis gas 5 generated in the first semi-carbonizing step 3 and the woody biomass 6 heated to the semi-carbonizing temperature, and a semi-carbonizing temperature of the heated woody biomass 6 The second semi-carbonizing step 8 for semi-carbonizing by holding for 30 minutes to 4 hours, the semi-carbide 10 discharged from the second semi-carbonizing step 8, the cooling step 12 for cooling the semi-carbide 10 to room temperature, A pyrolysis gas 11, which is a mixture of the cooled semi-carbide 13, the pyrolysis gas 5 generated in the first semi-carbonization process 3, and the pyrolysis gas generated in the second semi-carbonization process 8; Combustion by mixing combustion air 15 and auxiliary fuel 16 The combustion process 14, the hot gas 17 generated in the combustion process 14, the first distribution process 18 for distributing a part of the hot gas 17 to the first semi-carbonization process 3, and the first distribution process. The first semi-carbonizing hot gas 19, the second distributing step 20 for distributing a part of the hot gas 17 to the second semi-carbonizing step 8, and the second semi-carbonizing material distributed in the second distributing step The hot gas 21, the first semi-carbonizing hot gas 22 used to raise the temperature in the first semi-carbonizing step 3, and the first semi-carbonizing hot gas 22 used for semi-carbonizing in the second semi-carbonizing step 8. A hot gas treatment step 24 for treating the hot gas 23 for semi-carbonization, the hot gas 22 for first semi-carbonization with a lowered temperature, and the hot gas 23 for first semi-carbonization with a lowered temperature so that they can be released into the atmosphere; And exhaust gas 25.

[Second Embodiment]
Hereinafter, the biomass two-linked carbonization apparatus of the second embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 2, the two-coupled semi-carbonizing device 101 for biomass of the present embodiment evaporates water contained in the woody biomass 2 and raises the woody biomass 2 to a semi-carbonizing temperature. 103, the pyrolysis gas 5 generated in the first semi-carbonization step 103, and the woody biomass 6 heated to the semi-carbonization temperature, and the connecting device 107, and the woody biomass 6 at the semi-carbonization temperature for 30 minutes to 30 minutes Second semi-carbonizing device 108 that semi-carbonizes by holding for 4 hours, semi-carbide 10 discharged from second semi-carbonizing device 108, cooling device 112 that cools semi-carbide 10 to room temperature, and half that is cooled to room temperature The pyrolysis gas 11 which is a mixture of the carbide 13, the pyrolysis gas 5 generated in the first semi-carbonization device 103 and the pyrolysis gas generated in the second semi-carbonization device 108, the pyrolysis gas 11 and the combustion air 15 And auxiliary A combustion device 114 that mixes and mixes the fuel 16, a hot gas 17 generated in the combustion device 114, a first fan 115 that supplies a portion of the hot gas 17 to the first semi-carbonizing device 103, and a first half The first flow rate adjusting device 116 for adjusting the flow rate of the carbonizing hot gas 19, the second fan 117 for supplying a part of the hot gas 17 to the second semi-carbonizing step 108, and the flow rate of the second semi-carbonizing hot gas 21. A second flow rate adjusting device 118 for adjusting the temperature, the first semi-carbonized hot gas 22 which has been used to raise the temperature in the first semi-carbonizing device 103, and the semi-carbonized in the second semi-carbonizing device 108. The second semi-carbonized hot gas 23 whose temperature has been reduced, the first semi-carbonized hot gas 22 whose temperature has been reduced, and the second semi-carbonized hot gas 23 whose temperature has been reduced are processed so as to be released into the atmosphere. From the hot gas treatment device 124 and the exhaust gas 25 It is made.

The first semi-carbonizing device 103 includes a first semi-carbonizing device outer cylinder 102A and a first semi-carbonizing device inner cylinder 102B.
The first semi-carbonizing hot gas 19 is supplied to the space 104 between the first semi-carbonizing device outer cylinder and the first semi-carbonizing device inner cylinder.

The woody biomass 2 is transported in the first semi-carbonizing device inner cylinder 102B while being heated.
The woody biomass 2 may be transported by rotating the first semi-carbonizing device inner cylinder 102B.
The woody biomass 2 may be transported by installing a screw conveyor or the like in the first semi-carbonizing device inner cylinder 102B.

With the first temperature measuring device 119, the temperature of the first semi-carbonizing device inner cylinder 102B can be measured.
The first temperature measuring device 119 and the first flow rate adjusting device 116 are electrically connected, and the flow rate of the first semi-carbonizing hot gas 19 can be adjusted.

The second semi-carbonizing device 108 includes a second semi-carbonizing device outer cylinder 105A and a second semi-carbonizing device inner cylinder 105B.
The second semi-carbonizing hot gas 21 is supplied to the space 109 between the second semi-carbonizing device outer cylinder and the second semi-carbonizing device inner cylinder.

The woody biomass 6 heated to the semi-carbonizing temperature is transported in the second semi-carbonizing device inner cylinder 105B while being semi-carbonized.
You may convey the woody biomass 6 heated up to the semi-carbonization temperature by rotating the 2nd semi-carbonization apparatus inner cylinder 105B.
A screw conveyor or the like may be installed in the second semi-carbonizing device inner cylinder 105B to transport the woody biomass 6 heated to the semi-carbonizing temperature.

The temperature of the second semi-carbonizing device inner cylinder 105B can be measured by the second temperature measuring device 120.
The second temperature measuring device 120 and the flow rate adjusting device 118 are electrically connected, and the flow rate of the second semi-carbonizing hot gas 21 can be adjusted.

  The first temperature measurement device 119, the second temperature measurement device 120, and the combustion device 114 are electrically connected, and the flow rate of the combustion air 15 and the flow rate of the auxiliary fuel 16 can be adjusted.

  The connecting device 107 connects the first semi-carbonizing device 103 and the second semi-carbonizing device 108, and the woody biomass 6 heated to the carbonization temperature discharged from the first semi-carbonizing device, and the first semi-carbonizing device. The pyrolysis gas 5 generated in step 1 is transported from the first semi-carbonizing device to the second semi-carbonizing device without flowing out.

  The connecting device 107 may be provided with a transport device such as a screw conveyor.

The cooling device 112 includes a transport device 111 that transports the semicarbide 10 and a water cooling jacket 113.
The cooling water 110 is supplied to the water cooling jacket 113.
The transport device 111 may be a screw conveyor or the like.

  The embodiment of the present invention has been described in detail above, but various modifications can be made without departing from the technical idea of the present invention.

1 Two-linked semi-carbonization method for biomass 2 Woody biomass 3 First half-carbonization process 5 Pyrolysis gas 6 Woody biomass heated to half-carbonization temperature 7 Connection process 8 Second half-carbonization process 10 Semi-carbide 11 Pyrolysis gas 12 Cooling Step 13 Semicarbide Cooled to Normal Temperature 14 Combustion Step 15 Combustion Air 16 Auxiliary Fuel 17 Hot Gas 18 First Distribution Step 19 First Semicarbonization Hot Gas 20 Second Distribution Step 21 Second Semicarbonization Hot Gas 22 Hot semi-carbonizing gas 23 whose temperature has decreased 23 Hot semi-carbonizing gas 24 whose temperature has decreased 24 Hot gas treatment process 25 Exhaust gas 101 Two-coupled semi-carbonizing device 102 A for biomass First semi-carbonizing device outer cylinder 102 B First Semi-carbonizing device inner cylinder 103 First semi-carbonizing device 104 Space 105A between first semi-carbonizing device outer cylinder and first semi-carbonizing device inner cylinder Second semi-carbonizing device outer cylinder 105B In the second semi-carbonizing device 107 connecting device 108 second semi-carbonizing device 109 space 110 between second semi-carbonizing device outer cylinder and second semi-carbonizing device inner cylinder 110 cooling water 111 transport device 112 cooling device 113 water cooling jacket 114 combustion device 115 first fan 116 First flow rate adjustment device 117 Second fan 118 Second flow rate adjustment device 119 First temperature measurement device 120 Second temperature measurement device 124 Thermal gas processing device

It is a schematic block diagram of the 2 connection semi-carbonization method for biomass of 1st embodiment of this invention. It is the structure schematic of the two connection semi-carbonization apparatus for biomass of 2nd embodiment of this invention.

Claims (4)

A first semi-carbonization step of raising the biomass to about 250 ° C. to about 300 ° C., starting from normal temperature with the air shut off,
A second semi-carbonizing step for semi-carbonizing the biomass discharged from the first semi-carbonizing step by holding at about 250 ° C. to about 300 ° C. for 30 minutes to 4 hours in a state of shutting off air;
A cooling step of cooling and recovering the semi-carbide discharged from the second semi-carbonization step;
A combustion step of burning the pyrolysis gas generated in the first semi-carbonization step, the pyrolysis gas generated in the second semi-carbonization step, and auxiliary fuel;
In the first semi-carbonizing step and the second semi-carbonizing step, a heat utilization step utilizing heat generated in the combustion step;
A two-linked semi-carbonizing method for biomass characterized by comprising: A first semi-carbonizing device that heats the biomass from about 250 ° C. to about 300 ° C., starting from normal temperature, with the air shut off,
A second semi-carbonizing device that semi-carbonizes the biomass discharged from the first semi-carbonizing device by holding at about 250 ° C. to about 300 ° C. for 30 minutes to 4 hours in a state of shutting off air;
A cooling device for cooling and recovering the semi-carbide discharged from the second semi-carbonizing device;
A combustion apparatus for combusting pyrolysis gas generated in the first semi-carbonization apparatus, pyrolysis gas generated in the second semi-carbonization apparatus, and auxiliary fuel;
In the first semi-carbonizing device and the second semi-carbonizing device, a heat utilization device that utilizes heat generated in the combustion device,
A two-linked semi-carbonization system for biomass characterized by comprising: Keep the internal temperature at about 250 ° C to about 300 ° C,
With the air shut off,
While moving biomass inside the device,
Evaporate the water in the biomass,
Starting from room temperature to about 250 ° C to about 300 ° C,
Heating biomass,
The first semi-carbonizing device according to claim 2. Keep the internal temperature at about 250 ° C to about 300 ° C,
With the air shut off,
While moving inside the device,
By holding the biomass for about 30 minutes to about 4 hours,
Semi-carbonizing biomass discharged from the first semi-carbonizing device according to claim 2 and claim 3,
The second semi-carbonizing device according to claim 2.

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