JP2022045220A - Gasifier - Google Patents

Abstract

To prevent or suppress unnecessary raising of a temperature of a thermal decomposition part.SOLUTION: A rotation cylindrical part 21 of a gasifier 1 has a cylindrical shape around a central axis J1, and has a supply port 211 provided on one end and a discharge port 212 provided on the other end. Inside the rotation cylindrical part, a thermal decomposition part 4 and a modification part 5 are provided in this order from the supply port toward the discharge port. The thermal decomposition part produces a thermally decomposed gas and char by heating a treated object supplied from the supply port. The modification part produces a modified gas by steam reforming the thermally decomposed gas and char accompanied by partial combustion of the thermally decomposed gas. The modification part is provided with a conveyance path 524 for conveying the char from the side of the thermal decomposition part toward the side of the discharge port following rotation of the rotation cylindrical part, and is not provided with a conveyance path for conveying the char from the side of the discharge port toward the side of the thermal decomposition part. Thereby, unnecessary raising of a temperature of the thermal decomposition part can be prevented or suppressed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gasifier.

Conventionally, a gasification device that generates a pyrolysis gas and a char by heating an object to be treated such as biomass inside a rotary tubular portion (rotary kiln) that rotates about a central axis has been used. Further, a method of performing steam reforming inside the rotary tubular portion is also known. Such a device, also called a hybrid kiln, can reduce the manufacturing cost of the device and improve the energy efficiency as compared with the case where the device for reforming is manufactured individually.

For example, in the gasification device of Patent Document 1, pyrolysis gas is generated on the supply port side inside the rotary tubular portion. Further, a plurality of inner cylinders are provided on the discharge port side inside the rotary cylinder. In one inner cylinder portion, the char is conveyed from the supply port side to the discharge port side, and in the other inner cylinder portion, the char is conveyed from the discharge port side to the supply port side. This causes the char to circulate.

Japanese Patent No. 4547244

By the way, in the gasification apparatus of Patent Document 1, when steam reforming is performed with partial combustion of the pyrolysis gas, it is possible to easily secure the heat required for the steam reforming, but the pyrolysis gas is used. Since the heated char is returned to the generated thermal decomposition section on the supply port side, the temperature of the thermal decomposition section becomes unnecessarily high. In this case, the energy efficiency of the gasifier is reduced.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent or suppress an unnecessarily high temperature of a pyrolysis portion.

The invention according to claim 1 is a gasification device for gasifying an object to be processed, which has a tubular shape centered on a central axis and has a supply port at one end in a direction parallel to the central axis. Is provided, a discharge port is provided at the other end, a rotary tubular portion that rotates about the central axis, and a rotary tubular portion that is provided on the supply port side inside the rotary tubular portion and is provided from the supply port. A pyrolysis unit that generates a pyrolysis gas and char by heating the supplied object is provided between the pyrolysis unit and the discharge port inside the rotary tubular portion, and the pyrolysis gas is provided. It is provided with a reforming section that generates a reforming gas by steam reforming the pyrolysis gas and the char with partial combustion of the above, and in the reforming section, as the rotary tubular portion rotates. An outward transport path for transporting the char from the pyrolysis portion side to the discharge port side is provided, and a return transport path for transporting the char from the discharge port side to the thermal decomposition portion side is provided. Not provided.

The invention according to claim 2 is the gasification apparatus according to claim 1, wherein the cross-sectional area of the outward transport path perpendicular to the direction in which the outward transport path extends is used as the transport path cross-sectional area, and the outward transport path is defined as the cross-sectional area. The transport path cross-sectional area at a position away from the end on the thermal decomposition portion side to the discharge port side is smaller than the transport path cross-sectional area at the end on the thermal decomposition portion side.

The invention according to claim 3 is the gasification apparatus according to claim 2, wherein the reforming portion has an inner cylinder portion extending along the central axis, and the inner cylinder portion is the center. A cylindrical inner cylinder body extending along the axis, an inner cylinder shaft portion arranged near the center of the inner cylinder body and extending parallel to the central axis, and the inner cylinder shaft portion and the inner cylinder main body. A plate-like plate that spirally extends along the inner cylinder shaft portion while being connected to the peripheral surface, and together with the inner cylinder main body and the inner cylinder shaft portion, a spiral plate that forms the spiral outbound transport path. Be prepared.

The invention according to claim 4 is the gasification apparatus according to claim 3, wherein in the outbound transport path, between the inner peripheral surface of the inner cylinder body and the outer peripheral surface of the inner cylinder shaft portion. The width of the gap or the width of the gap between two portions adjacent to each other in the direction parallel to the central axis of the spiral plate is taken as the width of interest, and the end portion on the thermal decomposition portion side is directed toward the discharge port side. As a result, the attention width gradually decreases.

The invention according to claim 5 is the gasification device according to claim 3 or 4, wherein the inner cylinder portion is surrounded by the inner peripheral surface of the inner cylinder main body in a cross section of the inner cylinder portion perpendicular to the central axis. The area decreases from the end portion on the thermal decomposition portion side toward the discharge port side.

The invention according to claim 6 is the gasification apparatus according to claim 3, wherein the cross-sectional area of the inner cylinder shaft portion perpendicular to the central axis is from the end portion on the thermal decomposition portion side. It increases toward the discharge port side.

The invention according to claim 7 is the gasification apparatus according to claim 3 or 4, wherein the pitch of the spiral in the spiral plate is from the end portion on the thermal decomposition portion side toward the discharge port side. It gets smaller.

The invention according to claim 8 is the gasification apparatus according to any one of claims 1 to 7, wherein the reforming portion has a plurality of inner cylinder portions each extending along the central axis. The plurality of inner cylinder portions are fixed to the rotary tubular portion in a state of being parallel to each other.

According to the present invention, it is possible to prevent or suppress the temperature of the pyrolysis portion from becoming unnecessarily high.

It is a figure which shows the structure of the gasification apparatus. It is a figure which shows the gasification apparatus of the comparative example. It is a figure which shows another example of a gasification apparatus. It is a figure which shows another example of a gasification apparatus. It is a figure which shows another example of a gasification apparatus. It is a figure which shows another example of a gasification apparatus. It is a figure which shows another example of a gasification apparatus. It is a figure which shows another example of a gasification apparatus.

FIG. 1 is a diagram showing a configuration of a gasification device 1 according to an embodiment of the present invention. FIG. 1 shows a cross section of the gasifier 1 on a surface including the central axis J1 described later. The gasification device 1 is an external heat type rotary kiln (indirect heating type rotary kiln), which is a device that gasifies an object to be treated such as biomass to generate a reformed gas as a fuel gas. The reformed gas is used, for example, for power generation in a gas engine or the like. The waste to be treated is, for example, general waste, industrial waste, sewage sludge, woody biomass and the like.

The gasification device 1 includes a rotary tubular portion 21, an outer cylinder portion 26, an object supply unit 31, a gas introduction unit 32, a thermal decomposition unit 4, a reforming unit 5, and a control unit (not shown). ) And. The control unit is, for example, a computer equipped with a CPU or the like, and is responsible for overall control of the gasification device 1. The rotary tubular portion 21 has a cylindrical shape centered on the central axis J1 and is formed of, for example, a metal or an alloy (similar to other configurations provided in the rotary tubular portion 21). Typically, the cross-sectional shape of the rotary tubular portion 21 perpendicular to the central axis J1 is circular. The cross-sectional shape may be a polygon or the like when it can be regarded as a substantially circular shape. In the example of FIG. 1, the central axis J1 of the rotary tubular portion 21 is horizontal or substantially horizontal. Depending on the design of the gasifier 1, the central axis J1 may be tilted with respect to the horizontal direction.

In the rotary tubular portion 21, the end opening on one side in the direction parallel to the central axis J1 (hereinafter referred to as "axial direction") is the supply port 211, and the end opening on the other side is the discharge port 212. .. As will be described later, inside the rotary tubular portion 21, the thermal decomposition portion 4 and the reforming portion 5 are sequentially provided from the supply port 211 toward the discharge port 212. A supply-side annular portion 23 is provided in the vicinity of the supply port 211 inside the rotary tubular portion 21. The supply-side annular portion 23 is an annular member that projects from the inner peripheral surface of the rotary tubular portion 21 over the entire circumference in the circumferential direction centered on the central axis J1. The height of the supply-side annular portion 23 from the inner peripheral surface of the rotary tubular portion 21 (the height of the inner peripheral surface of the supply-side annular portion 23 in the direction perpendicular to the inner peripheral surface of the rotary tubular portion 21) is all. It is almost constant over the circumference.

A flange portion 213 is provided at the end of the rotary tubular portion 21 on the supply port 211 side. The flange portion 213 is an annular plate member centered on the central axis J1. A pair of rollers 221 are provided below the flange portion 213. The pair of rollers 221 are separated from each other in the direction perpendicular to the paper surface of FIG. The flange portion 213 is rotatably supported by a pair of rollers 221.

Further, on the outer peripheral surface of the rotary tubular portion 21, a flange portion 214 is provided near the end portion on the discharge port 212 side. Like the flange portion 213, the flange portion 214 is also an annular plate member centered on the central axis J1 and is rotatably supported by a pair of rollers 222. In the gasifier 1, a rotary mechanism 22 having a motor and a speed reducer is connected to the roller 221. By rotating the roller 221 by the rotary mechanism 22, the rotary tubular portion 21 is continuously centered on the central axis J1. Rotate to. The rotation speed of the rotary tubular portion 21 is, for example, constant. The structure for rotating the rotary tubular portion 21 may be appropriately changed.

The outer cylinder portion 26 has a cylindrical shape centered on the central axis J1 and is formed of, for example, a metal or an alloy. The outer cylinder portion 26 surrounds the circumference of the rotary tubular portion 21 between the two flange portions 213 and 214, and forms a tubular space 260 with the outer peripheral surface of the rotary tubular portion 21. The width between the rotary tubular portion 21 and the outer tubular portion 26, that is, the width of the tubular space 260 in the radial direction centered on the central axis J1, is substantially constant over the entire length. Circular walls 261,262 are provided at both ends of the outer cylinder portion 26 in the axial direction. Each annular wall 261,262 is an annular member centered on the central axis J1 and projects from the outer cylinder portion 26 toward the rotary tubular portion 21. The end surface of the annular wall 261,262 on the rotary tubular portion 21 side is in contact with the outer peripheral surface of the rotary tubular portion 21 via, for example, a sliding member. As a result, a seal structure is formed between the annular walls 261,262 and the rotary tubular portion 21. The outer cylinder portion 26 is a fixed body that does not rotate.

An outflow port 263 and an inflow port 264 are formed in the outer cylinder portion 26. The outlet 263 is provided in the vicinity of the annular wall 261 on the supply port 211 side and is connected to the cylindrical space 260. The inflow port 264 is provided in the vicinity of the annular wall 262 on the discharge port 212 side and is connected to the cylindrical space 260. A predetermined heat source fluid is supplied to the inflow port 264. The temperature of the heat source fluid at the inlet 264 is, for example, 900 to 1100 ° C. The heat source fluid flows through the cylindrical space 260 and is discharged from the outlet 263. The outer peripheral surface of the rotary tubular portion 21 is heated by the heat source fluid flowing through the tubular space 260.

The object to be processed 31 includes a hopper 311 and a screw feeder 312. The object to be processed is stored in the hopper 311. The screw feeder 312 includes a rotation mechanism 313 and a screw 314. The screw 314 extends along the central axis J1 from the inside of the hopper 311 to the supply port 211 of the rotary tubular portion 21. The rotation mechanism 313 has a motor and a speed reducer, and rotates the screw 314. As a result, the object to be processed in the hopper 311 is supplied to the inside of the rotary tubular portion 21 from the supply port 211. The supply of the object to be processed into the rotary tubular portion 21 by the object supply unit 31 may be continuous or intermittent. The screw shaft 315 of the screw 314 is hollow. An introduction pipe 321 described later is provided in the hollow portion of the screw shaft 315. The introduction pipe 321 extends along the central axis J1.

The thermal decomposition section 4 is provided on the supply port 211 side inside the rotary tubular section 21. The thermal decomposition section 4 includes a partition plate 41 and a guide section 42. The partition plate 41 is a plate member parallel to the central axis J1 and is arranged on the central axis J1. Both ends of the partition plate 41 in the direction perpendicular to the central axis J1 are fixed to the inner peripheral surface of the rotary tubular portion 21. The internal space of the rotary tubular portion 21 when viewed along the central axis J1 is bisected by the partition plate 41. The plate thickness (thickness between the main surfaces) of the partition plate 41 is relatively large, and a through hole 411 is provided on the central axis J1. The introduction pipe 321 described above is inserted into the through hole 411.

The guide portion 42 includes a plurality of linear protrusions 421. A part of the linear protrusions 421 protrudes from one main surface of the partition plate 41, and the remaining linear protrusions 421 project from the other main surface of the partition plate 41. The linear protrusions 421 provided on each main surface of the partition plate 41 are parallel to each other. In the example of FIG. 1, all the linear protrusions 421 extend in the same direction inclined with respect to the axial direction. In FIG. 1, when the partition plate 41 shown by a solid line is rotated 180 degrees about the central axis J1, the linear protrusion 421 arranged on the front side is shown by a two-dot chain line. The tilting direction of the linear protrusion 421 of the two-dot chain line is opposite to the tilting direction of the linear protrusion 421 of the solid line (direction inverted with respect to the central axis J1).

The partition plate 41 rotates about the central axis J1 with the rotation of the rotary tubular portion 21. When the direction of one main surface of the partition plate 41 is switched from the upper side to the lower side in the rotation of the partition plate 41, the object to be processed (including the char described later) on the main surface is supplied by the linear protrusion 421. It is sent to the 211 side. The object to be processed collides with the supply-side annular portion 23 at the lower end of the rotary tubular portion 21 and stays in the vicinity of the partition plate 41. Further, when the direction of the other main surface of the partition plate 41 is switched from the upper side to the lower side, the object to be processed on the main surface is sent to the side opposite to the supply port 211 by the linear protrusion 421. As will be described later, char is retained between the partition plate 41 and the reforming portion 5, and the object to be treated tends to stay in the vicinity of the partition plate 41. As described above, in the guide portion 42, the object to be processed is sent toward the supply port 211 side in the rotation angle range of one of the rotary tubular portions 21, and is processed in the other rotation angle range of the rotary tubular portion 21. The thing is sent toward the side opposite to the supply port 211. As a result, the object to be processed reciprocates (circulates) between the vicinity of both ends of the partition plate 41 in the axial direction, and the object to be processed stays in the thermal decomposition unit 4.

As described above, the rotary tubular portion 21 is heated by the heat source fluid flowing through the tubular space 260. In the thermal decomposition unit 4, the object to be treated is heated at, for example, a temperature of 400 ° C. or higher (preferably 700 ° C. or lower) to cause thermal decomposition, and thermal decomposition gas and char are generated. The discharge port 212 is depressurized by an attraction fan or the like (not shown), and the pyrolysis gas flows toward the discharge port 212. The pyrolysis gas may contain tar vapor (which becomes liquid at room temperature), powder char, and the like. The char that is not contained in the pyrolysis gas (for example, the char that is larger than the char of the powder) stays in the pyrolysis unit 4. When the object to be processed is supplied from the object to be processed 31, a part of the char that stays in the pyrolysis unit 4 is pushed out to the reforming unit 5 side (discharge port 212 side). In the following description, the term "char" simply means char that is not contained in the pyrolysis gas. If the object to be treated contains a non-combustible material, the non-combustible material also moves with the char.

As described above, the reforming section 5 is provided between the thermal decomposition section 4 and the discharge port 212 inside the rotary tubular section 21. The reforming portion 5 includes one inner cylinder portion 52 extending along the central axis J1. The inner cylinder portion 52 includes an inner cylinder main body 521. The inner cylinder main body 521 has a tubular shape extending along the central axis J1 and is a member that protrudes from the inner peripheral surface of the rotary tubular portion 21 over the entire circumference in the circumferential direction. The height of the inner cylinder main body 521 from the inner peripheral surface of the rotary tubular portion 21 (the height of the inner peripheral surface of the inner cylinder main body 521 in the direction perpendicular to the inner peripheral surface of the rotary tubular portion 21) is the discharge port 212. It gradually increases as it approaches. That is, the inner peripheral surface of the inner cylinder main body 521 is a conical base surface whose diameter decreases as it approaches the discharge port 212.

The cylindrical portion 216 further includes an inner cylinder shaft portion 522 and a spiral plate 523. The inner cylinder shaft portion 522 extends parallel to the central axis J1 and is arranged near the center of the inner cylinder main body 521. In the example of FIG. 1, the inner cylinder shaft portion 522 is arranged on the central axis J1, and the diameter of the inner cylinder shaft portion 522 is constant. The spiral plate 523 has a plate shape that extends spirally along the inner cylinder shaft portion 522 inside the inner cylinder main body 521, and is provided from one end to the other end of the inner cylinder main body 521. The spiral plate 523 connects the outer peripheral surface of the inner cylinder shaft portion 522 and the inner peripheral surface of the inner cylinder main body 521. For example, the spiral plate 523 is fixed substantially perpendicular to the outer peripheral surface of the inner cylinder shaft portion 522, and is also fixed substantially perpendicular to the inner peripheral surface of the inner cylinder main body 521. In the spiral plate 523 of FIG. 1, the inclination angle with respect to the axial direction at the portion in contact with the inner peripheral surface of the inner cylinder main body 521 is substantially constant throughout (the same applies to the portion in contact with the outer peripheral surface of the inner cylinder shaft portion 522). , The pitch of the spiral in the spiral plate 523 is also constant.

In the reforming section 5, the inner cylinder main body 521, the inner cylinder shaft portion 522, and the spiral plate 523 provide a spiral path 524 (since it is used for transporting chars as described later, it is hereinafter referred to as “transport path 524”. .) Is formed. In the example of FIG. 1, the plate thickness of the spiral plate 523 is constant, and the width of the gap between two portions of the spiral plate 523 adjacent to each other in the axial direction is substantially constant. That is, the width of the transport path 524 in the axial direction is almost constant. In the reforming section 5, as a general rule, the pyrolysis gas and the char can pass through only the transport path 524.

In the present embodiment, the spiral plate 523 and the transport path 524 proceed clockwise around the inner cylinder shaft portion 522 from the thermal decomposition portion 4 side toward the discharge port 212 side. Further, when viewed from the supply port 211 side toward the discharge port 212 side, the rotary tubular portion 21 rotates counterclockwise with respect to the central axis J1. Inside the inner cylinder portion 52, the char located at the lower part of the inner cylinder portion 52 moves in the transport path 524 from the thermal decomposition portion 4 side toward the discharge port 212 side as the rotary tubular portion 21 rotates. It is conveyed and discharged to the outside of the inner cylinder portion 52 at the end portion on the discharge port 212 side. In the gasification device 1, chars are sequentially discharged from the inner cylinder portion 52 and discharged from the discharge port 212. At the end of the inner cylinder portion 52 on the thermal decomposition portion 4 side, a structure may be provided in which the char is taken into the inside of the inner cylinder portion 52 as the rotary tubular portion 21 rotates.

Here, in the transport path 524, the width of the gap between the inner peripheral surface of the inner cylinder main body 521 and the outer peripheral surface of the inner cylinder shaft portion 522 (the width indicated by arrows W1 and W2 in FIG. 1; hereinafter, " Attention width "). As described above, the inner peripheral surface of the inner cylinder main body 521 is a conical base surface, and is from the end portion of the transport path 524 on the thermal decomposition portion 4 side (hereinafter referred to as “upstream side end portion”) to the discharge port 212 side. The radius of the inner peripheral surface gradually decreases as it goes toward it. On the other hand, the radius of the inner cylinder shaft portion 522 is constant. Therefore, in the transport path 524, the attention width gradually decreases from the upstream end toward the discharge port 212 side. In FIG. 1, the attention width at the upstream end of the transport path 524 is indicated by an arrow W1, and the attention width at a position away from the upstream end toward the discharge port 212 is indicated by an arrow W2. The attention width W2 is smaller than the attention width W1 at the upstream end. The width of interest corresponds to the height of the transport path 524 in the radial direction. Therefore, the area of the cross section of the transport path 524 perpendicular to the direction in which the transport path 524 extends (hereinafter, referred to as “transport path cross-sectional area”) is maximum at the upstream end of the transport path 524 and is discharged from the upstream end. It gradually becomes smaller toward the exit 212 side.

In the present embodiment, the cross-sectional shape of the inner peripheral surface of the inner cylinder main body 521 perpendicular to the central axis J1 is circular, but if the cross-sectional shape is considered to be substantially circular, it may be polygonal or the like. good. In this case as well, in the cross section of the inner cylinder portion 52 perpendicular to the central axis J1, the area surrounded by the inner peripheral surface of the inner cylinder main body 521 is the upstream end of the transport path 524, as in the case where the cross-sectional shape is circular. It is preferable that the size gradually decreases toward the discharge port 212 side from the portion. As a result, the width of interest and the cross-sectional area of the transport path can be gradually reduced from the upstream end portion toward the discharge port 212 side.

The gas introduction unit 32 includes an introduction pipe 321 and a mixed gas supply unit 326. As described above, the introduction pipe 321 penetrates the hollow portion of the screw shaft 315 and the through hole 411 of the partition plate 41. The mixed gas supply unit 326 is connected to the introduction pipe 321. The tip of the introduction pipe 321 is arranged at a position directly facing the reforming portion 5. A spout 322 is provided at the tip of the introduction pipe 321. The spout 322 is located near the end of the reforming section 5 on the thermal decomposition section 4 side.

The mixed gas supply unit 326 supplies the mixed gas containing oxygen-containing gas and water vapor to the introduction pipe 321 so that the mixed gas is ejected from the ejection port 322 of the introduction pipe 321. The oxygen-containing gas is, for example, air or oxygen-enriched air, and in the present embodiment, is preheated high-temperature air. The temperature of the mixed gas is, for example, 200 to 300 ° C. The mixed gas ejected from the ejection port 322 is mixed with the pyrolysis gas flowing toward the reforming unit 5, and the flammable gas contained in the pyrolysis gas and the steam of tar are partially combusted (that is, a part). Pyrolysis gas burns.). The heat of the reforming gas generated by the gasification device 1 or the exhaust gas of a gas engine using the reforming gas may be used for heating the oxygen-containing gas and generating steam.

The transport path 524 of the reforming section 5 is filled with a certain amount of char, and most of the pyrolysis gas flowing through the transport path 524 passes through the gaps between the chars existing in the transport path 524. , Flows into the space between the reforming section 5 and the discharge port 212. That is, in the transport path 524, good air-solid contact (air-solid reaction) between the pyrolysis gas and the char is realized. At this time, the tar remaining in the pyrolysis gas and the char of the powder are collected (trapped) in the pores of the char in the transport path 524.

Further, due to the partial combustion of the pyrolysis gas, the char in the transport path 524 and the pyrolysis gas flowing through the transport path 524 become hot. Further, the mixed gas mixed with the pyrolysis gas contains water vapor. As a result, the hydrocarbon gas or the like contained in the pyrolysis gas is converted into a gas such as hydrogen (H ₂ ) or carbon monoxide (CO) by the steam reforming reaction (that is, steam reformed). In addition, the tar and powder chars collected in the chars, as well as the chars themselves, are steam reformed. Of course, tar and powder chars contained in the pyrolysis gas and not collected by the chars may also be steam reformed. In the transport path 524, the volume of the char decreases from the upstream end of the transport path 524 toward the discharge port 212 due to the steam reforming of the char.

As described above, in the reforming section 5 to which the pyrolysis gas and the char are sent from the pyrolysis section 4, the reforming gas is produced by steam reforming the pyrolysis gas and the char with partial combustion of the pyrolysis gas. Generated. The temperature of the char and the pyrolysis gas in the reforming section 5 is, for example, 700 ° C. or higher, preferably 800 ° C. or higher, and more preferably 900 ° C. or higher. The temperature is, for example, 1100 ° C. or lower. The reformed gas is discharged from the rotary tubular portion 21 via the discharge port 212.

A separation unit 33 is connected to the discharge port 212. The separation portion 33 is a pipe extending in the vertical direction. In the separation unit 33, the reformed gas flows upward, passes through, for example, a boiler, and then is supplied to a gas engine or the like. Further, the char discharged from the discharge port 212 falls downward at the separation portion 33 and is collected. The lower part of the separation unit 33 is a char collection unit. The char collection unit also collects substances other than char, such as incombustibles.

Here, a gasifier of a comparative example will be described. FIG. 2 is a diagram showing a gasifier 8 of a comparative example. In the gasification device 8 of the comparative example, a plurality of inner cylinder portions 831, 832 are arranged in parallel in the reforming portion 81. Each inner cylinder portion 831,832 has a spiral plate. With the rotation of the rotary tubular portion 21, the char is conveyed from the pyrolysis portion 4 side to the discharge port 212 side in one inner cylinder portion 831, and in the other inner cylinder portion 832, the discharge port 212 side. The char is transported toward the pyrolysis unit 4 side. That is, the inner cylinder portion 831 is provided with an outward transport path 833 for transporting the char from the thermal decomposition portion 4 side toward the discharge port 212 side, and the inner cylinder portion 832 is provided with the thermal decomposition portion 4 side from the discharge port 212 side. A return transport path 834 for transporting the char toward the surface is provided, and the char circulates in the reforming section 81.

In the gasification device 8 of the comparative example of FIG. 2, the char that has become hot due to the partial combustion of the pyrolysis gas is returned to the pyrolysis section 4 side via the return transfer path 834, so that the pyrolysis section 4 and the reforming are performed. The temperature of the unit 81 is made uniform. The generation of pyrolysis gas and char in the pyrolysis section 4 does not require a temperature as high as that of the reforming section 81 in which steam reforming is performed. Therefore, in the gasification device 8 of the comparative example, the heat generated by the partial combustion of the pyrolysis gas is used for unnecessary temperature rise of the pyrolysis unit 4, and the energy efficiency of the gasification device 8 is lowered.

On the other hand, in the gasification device 1 of FIG. 1, in the reforming section 5, the char is transported from the thermal decomposition section 4 side to the discharge port 212 side as the rotary tubular section 21 rotates. A path (that is, a transfer path 524) is provided, and a return transfer path for transporting the char from the discharge port 212 side to the pyrolysis unit 4 side is not provided. As described above, in the reforming section 5 provided with only the outward transport path, the high temperature char is not returned to the thermal decomposition section 4. This prevents or suppresses the temperature of the pyrolysis unit 4 from becoming unnecessarily high (that is, realizes a preferable temperature distribution in which the temperature of the pyrolysis unit 4 is lower than that of the reforming unit 5). It is possible to suppress a decrease in energy efficiency in the gasification device 1.

FIG. 3 is a diagram showing another example of the gasifier. In the gasification device 1a of FIG. 3, the spiral plate 523 connects the outer peripheral surface of the inner cylinder shaft portion 522 and the inner peripheral surface of the rotary tubular portion 21, and the spiral plate 523 is connected at the rotary tubular portion 21. The portion also serves as the inner cylinder main body 521. That is, the inner cylinder portion 52 includes a part of the rotary cylinder portion 21 in addition to the inner cylinder shaft portion 522 and the spiral plate 523. The inner cylinder portion 52 may include a cylindrical inner cylinder main body 521 fixed inside the rotary tubular portion 21 (the same applies to other examples in which a part of the rotary tubular portion 21 also serves as the inner cylinder main body 521). ..

In the gasification device 1a of FIG. 3, the width of the gap (that is, the width of interest) between the inner peripheral surface of the rotary tubular portion 21 and the outer peripheral surface of the inner cylinder shaft portion 522 is constant in the entire transport path 524. , The cross-sectional area of the transport path is also constant. Also in the gasification device 1a, since only the outward transport path (transport path 524) is provided and the return transport path is not provided, it is possible to prevent or suppress the temperature of the thermal decomposition unit 4 from becoming unnecessarily high. Is.

Next, the gasification device 1 of FIG. 1 and the gasification device 1a of FIG. 3 are compared. In the gasification device 1 of FIG. 1 and the gasification device 1a of FIG. 3, the char located at the lower part of the inner cylinder portion 52 rotates in the transport path 524 on the thermal decomposition portion 4 side as the rotary tubular portion 21 rotates. Moves toward the discharge port 212 side. Here, in the movement of the char in the transport path 524, the area of the cross section of the char at each position (the area of the cross section perpendicular to the direction in which the transport path 524 extends) is the area of the cross section of the transport path 524 at the position (transport). The ratio to the road cross-sectional area) is called the "char cross-sectional filling rate".

As described above, in the gasification device 1 of FIG. 1, the transport path cross-sectional area is gradually reduced, whereas in the gasification device 1a of FIG. 3, the transport path cross-sectional area is constant. Therefore, in the gasification device 1, the cross-sectional filling rate of the char at a position away from the upstream end of the transport path 524 toward the discharge port 212 tends to be larger than that of the gasification device 1a (that is, in the transport path 524). On the other hand, the char tends to be dense.) Actually, the volume of the char decreases from the upstream end to the discharge port 212 side in the transport path 524, but the gasification device 1 in FIG. 1 has a transport path as compared with the gasification device 1a in FIG. At 524, the pyrolysis gas and the char are easily in contact with each other (that is, the contact rate between the pyrolysis gas and the char is increased). As a result, it is possible to efficiently remove the tar contained in the pyrolysis gas by using the char and reduce the tar contained in the reformed gas. It also enables efficient steam reforming of chars (including tar and powder chars collected in chars).

In the gasification device 1, the maximum value of the cross-sectional filling rate of the char in the transport path 524 is, for example, 60% or more, preferably 70% or more, and more preferably 80% or more. From the viewpoint of securing a portion having a high cross-sectional filling rate of the char in the transport path 524, the ratio of the volume of the char existing in the inner cylinder portion 52 to the internal volume of the inner cylinder portion 52, that is, the modification. The filling rate of the char in the portion 5 is, for example, 20% or more, preferably 25% or more, and more preferably 30% or more. The charging rate of the char can be changed by adjusting the supply speed of the object to be processed by the object supply unit 31 to be processed.

FIG. 4 is a diagram showing another example of the gasifier 1. In the gasification device 1 of FIG. 4, a part of the rotary tubular portion 21 also serves as the inner cylinder main body 521, and the inner cylinder portion 52 partially forms the rotary tubular portion 21 as in the example of FIG. include. Further, the shape of the inner cylinder shaft portion 522a is different from that of the inner cylinder shaft portion 522 of FIG. Other configurations are the same as those of the gasifier 1 of FIG. 1, and the same configurations are designated by the same reference numerals.

The inner cylinder shaft portion 522a is arranged near the center of the rotary tubular portion 21 and extends in parallel with the center shaft J1. The radius of the inner cylinder shaft portion 522a gradually increases from the upstream end of the transport path 524 toward the discharge port 212. That is, the cross-sectional area of the inner cylinder shaft portion 522a perpendicular to the central axis J1 gradually increases from the upstream end portion toward the discharge port 212 side. The spiral plate 523 connects the outer peripheral surface of the inner cylinder shaft portion 522a and the inner peripheral surface of the rotary tubular portion 21. In the transport path 524, the width of the gap between the inner peripheral surface of the rotary tubular portion 21 and the outer peripheral surface of the inner cylindrical shaft portion 522a, that is, the width of interest gradually increases from the upstream end portion toward the discharge port 212 side. It gets smaller.

In the gasification device 1 of FIG. 4, the cross-sectional area of the transport path in the transport path 524 gradually decreases from the upstream end portion toward the discharge port 212 side. As a result, the pyrolysis gas and the char can be easily brought into contact with each other in the transport path 524, and the tar contained in the pyrolysis gas can be efficiently removed. Further, by not providing the return transport path, it is possible to prevent or suppress the temperature of the thermal decomposition section 4 from becoming unnecessarily high (similar to FIGS. 5 to 8 described later). In the example of FIG. 4, the cross-sectional shape of the inner cylinder shaft portion 522a perpendicular to the central axis J1 is circular, but the cross-sectional shape may be a polygon or the like.

FIG. 5 is a diagram showing another example of the gasifier 1. Also in the gasification device 1 of FIG. 5, a part of the rotary tubular portion 21 also serves as the inner cylinder main body 521, and the inner cylinder portion 52 includes a part of the rotary tubular portion 21. Further, the shape of the spiral plate 523a is different from that of the spiral plate 523 of FIG. Other configurations are the same as those of the gasifier 1 of FIG. 1, and the same configurations are designated by the same reference numerals.

The spiral plate 523a extends spirally around the inner cylinder shaft portion 522 and is provided from one end to the other end of the inner cylinder shaft portion 522. The spiral plate 523a connects the outer peripheral surface of the inner cylinder shaft portion 522 and the inner peripheral surface of the rotary tubular portion 21. The pitch of the spiral in the spiral plate 523a gradually decreases from the upstream end of the transport path 524 toward the discharge port 212. In the example of FIG. 5, the plate thickness of the spiral plate 523a is constant. When the width of the gap between two portions adjacent to each other in the axial direction in the spiral plate 523a is referred to as "attention width", the attention width gradually decreases from the upstream end of the transport path 524 toward the discharge port 212. .. In FIG. 5, the attention width at the upstream end of the transport path 524 is indicated by an arrow W3, and the attention width at a position away from the upstream end toward the discharge port 212 is indicated by an arrow W4. The attention width W4 is smaller than the attention width W3 at the upstream end.

The attention width corresponds to the width of the transport path 524 in the axial direction. Further, the width of the gap (corresponding to the height of the transport path 524) between the inner peripheral surface of the rotary tubular portion 21 and the outer peripheral surface of the inner cylinder shaft portion 522 is constant in the entire transport path 524. Therefore, in the gasification device 1 of FIG. 5, the cross-sectional area of the transport path in the transport path 524 gradually decreases from the upstream end portion toward the discharge port 212 side. As a result, the pyrolysis gas and the char can be easily brought into contact with each other in the transport path 524, and the tar contained in the pyrolysis gas can be efficiently removed. In the gasification device 1, the thickness of the spiral plate 523 is gradually increased from the upstream end of the transport path 524 toward the discharge port 212 while keeping the pitch of the spiral in the spiral plate 523 constant (see FIG. 3). Therefore, it is possible to gradually reduce the cross-sectional area of the transport path.

The gasification devices 1 and 1a can be modified in various ways.

In the gasification device 1 of FIGS. 1, 4 and 5, the cross-sectional area of the transport path gradually decreases from the upstream end of the transport path 524 toward the discharge port 212, but the cross-sectional area of the transport path suddenly decreases. It may be smaller. For example, in the gasification device 1 of FIG. 6, the cross-sectional area of the inner cylinder shaft portion 522b perpendicular to the central axis J1 suddenly changes at the end portion on the discharge port 212 side and becomes larger than the other portions. As a result, the cross-sectional area of the transport path at the position away from the upstream end on the transport path 524 toward the discharge port 212 (the end on the discharge port 212 side in FIG. 6) is larger than the cross-sectional area of the transport path at the upstream end. Also becomes smaller. As a result, it is possible to facilitate the contact between the pyrolysis gas and the char, and it is possible to efficiently remove the tar contained in the pyrolysis gas.

As described above, in the gasification device 1, it is preferable that the cross-sectional area of the inner cylinder shaft portion perpendicular to the central axis J1 increases from the upstream end portion toward the discharge port 212 side. Similarly, in the cross section of the inner cylinder portion 52 perpendicular to the central axis J1, the area surrounded by the inner peripheral surface of the inner cylinder main body, or the pitch of the spiral in the spiral plate, is directed from the upstream end to the discharge port 212 side. It is preferable that the size is small. This makes it possible to easily make the cross-sectional area of the transport path at a position away from the upstream end portion toward the discharge port 212 side smaller than the cross-sectional area of the transport path at the upstream end portion. In order to make the pyrolysis gas more easily in contact with the char, it is preferable that the cross-sectional area of the transport path gradually decreases from the upstream end to the discharge port 212 side as the volume of the char decreases.

In the above embodiment, only one inner cylinder portion 52 is provided in the reforming portion 5, but as shown in FIG. 7, a plurality of inner cylinder portions 52 may be provided in the reforming portion 5a. Each inner cylinder portion 52 has a tubular outer shape extending along the central axis J1, and the plurality of inner cylinder portions 52 are fixed to the rotary tubular portion 21 in a state of being parallel to each other. Each inner cylinder portion 52 includes an inner cylinder main body 521, an inner cylinder shaft portion 522, and a spiral plate 523, similarly to the inner cylinder portion 52 in FIG. In the transport path 524 formed by the inner cylinder main body 521, the inner cylinder shaft portion 522, and the spiral plate 523, the char is generated from the thermal decomposition portion 4 side toward the discharge port 212 side as the rotary tubular portion 21 rotates. Be transported.

In the gasification device 1 of FIG. 7, since the transport paths 524 of all the inner cylinder portions 52 are outward transport paths, it is possible to prevent or suppress the temperature of the thermal decomposition section 4 from becoming unnecessarily high. .. Further, in the transport path 524 (may be a transport path 524 of a part of the plurality of transport paths 524), the transport path cross-sectional area at a position away from the upstream end portion toward the discharge port 212 is upstream. Since it is smaller than the cross-sectional area of the transport path at the side end, tar contained in the pyrolysis gas can be efficiently removed. The structure of the reforming portions 5, 5a provided only with the outward transport path may be appropriately changed.

The structure of the thermal decomposition unit 4 may be appropriately changed, and for example, a structure that does not use the partition plate 41 may be adopted.

As shown in FIG. 8, the gas introduction section 32 may be provided with an introduction pipe 321a that penetrates the discharge port 212 and the reforming section 5. In the example of FIG. 8, the tip (spout 322) of the introduction pipe 321a is arranged between the pyrolysis portion 4 and the reforming portion 5 (inner cylinder shaft portion 522) in the axial direction. The mixed gas supply unit 326 supplies the mixed gas to the introduction pipe 321a, so that the mixed gas is ejected from the ejection port 322. This makes it possible for the reforming unit 5 to appropriately steam reform the pyrolysis gas and char.

In the gas introduction unit 32, the oxygen-containing gas and water vapor may be introduced into the inside of the rotary tubular portion 21 via separate introduction pipes. Further, the spout of the introduction pipe may be arranged inside the reforming section 5, 5a or at an arbitrary position between the reforming section 5, 5a and the supply port 211. In order to efficiently generate partial combustion in the reforming portions 5, 5a, at least the outlet of the introduction pipe for ejecting the oxygen-containing gas should be arranged in the vicinity of the supply port 211 side end of the reforming portions 5, 5a. Is preferable.

In the above embodiment, indirect heating is performed by the heat source fluid flowing through the tubular space 260 in both the pyrolysis section 4 and the reforming section 5, 5a, but the reforming using the heat of partial combustion of the pyrolysis gas is performed. In parts 5 and 5a, indirect heating by the heat source fluid may be omitted. Further, in the system including the gasification devices 1, 1a, for example, the heat obtained by burning the char recovered in the separation unit 33 is used for indirect heating of the object to be processed in the thermal decomposition unit 4. Although it is possible to increase energy efficiency, depending on the design of the system, heating of the object to be processed may be performed by electricity or the like.

The reformed gas obtained by the gasifiers 1, 1a may be used in a gas turbine type or a fuel cell (solid oxide fuel cell (SOFC) or the like) type power generation device in addition to the gas engine. Further, the reformed gas may be used as a fuel gas for various purposes, and may be further used as a liquid fuel by converting it into a liquid.

The above-described embodiments and configurations in the respective modifications may be appropriately combined as long as they do not conflict with each other.

1,1a Gasifier 4 Thermal decomposition part 5,5a Modification part 21 Rotating tubular part 52 Inner cylinder part 211 Supply port 212 Outlet port 521 Inner cylinder main body 522, 522a, 522b Inner cylinder shaft part 523, 523a Spiral plate 524 Transport path J1 Central axis W1 to W4 Attention width

Claims (8)

A gasifier that gasifies the object to be treated.
It has a cylindrical shape centered on the central axis, has a supply port at one end in a direction parallel to the central axis, and has a discharge port at the other end, and rotates about the central axis. Rotating tubular part and
A pyrolysis section provided on the supply port side inside the rotary tubular portion to generate a pyrolysis gas and char by heating an object to be processed supplied from the supply port.
It is provided between the pyrolysis portion and the discharge port inside the rotary tubular portion, and is reformed by steam reforming the pyrolysis gas and the char with partial combustion of the pyrolysis gas. The reformer that produces gas and
Equipped with
In the reforming section, an outward transport path for transporting the char from the pyrolysis section side to the discharge port side is provided as the rotary tubular portion rotates, and the heat is generated from the discharge port side. A gasification device characterized in that a return transport path for transporting the char is not provided toward the decomposition unit side. The gasification device according to claim 1.
The cross-sectional area of the outward transport path perpendicular to the extending direction of the outward transport path is used as the transport path cross-sectional area, and the transport is performed at a position away from the end on the thermal decomposition portion side to the discharge port side in the outward transport path. A gasification device characterized in that the road cross-sectional area is smaller than the transport road cross-sectional area at the end portion on the thermal decomposition portion side. The gasification device according to claim 2.
The modified portion has an inner cylinder portion extending along the central axis.
The inner cylinder part
The inner cylinder body, which is a cylinder extending along the central axis,
An inner cylinder shaft portion arranged near the center of the inner cylinder body and extending in parallel with the central axis, and an inner cylinder shaft portion.
It is a plate shape that extends spirally along the inner cylinder shaft portion while connecting the inner cylinder shaft portion and the inner peripheral surface of the inner cylinder main body, and is spiral together with the inner cylinder main body and the inner cylinder shaft portion. The spiral plate forming the outbound transport path and
A gasifier characterized by being equipped with. The gasification device according to claim 3.
In the outbound transport path, the width of the gap between the inner peripheral surface of the inner cylinder body and the outer peripheral surface of the inner cylinder shaft portion, or the spiral plate adjacent to each other in the direction parallel to the central axis 2 A gasification device, wherein the width of the gap between the two portions is set as the width of interest, and the width of attention gradually decreases from the end portion on the thermal decomposition portion side toward the discharge port side. The gasification device according to claim 3 or 4.
In the cross section of the inner cylinder portion perpendicular to the central axis, the area surrounded by the inner peripheral surface of the inner cylinder main body decreases from the end portion on the thermal decomposition portion side toward the discharge port side. Characterized gasification device. The gasification device according to claim 3 or 4.
A gasification device characterized in that the cross-sectional area of the inner cylinder shaft portion perpendicular to the central axis increases from the end portion on the thermal decomposition portion side toward the discharge port side. The gasification device according to claim 3 or 4.
A gasification device characterized in that the pitch of the spiral in the spiral plate becomes smaller from the end portion on the thermal decomposition portion side toward the discharge port side. The gasification device according to any one of claims 1 to 7.
The modified portion has a plurality of inner cylinder portions, each of which extends along the central axis.
A gasification device characterized in that the plurality of inner cylinder portions are fixed to the rotary tubular portion in a state of being parallel to each other.

Images