JP2010070734A - Reformer for pyrolysis gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the tar gasification rate of a reformer for reforming tar in a pyrolysis gas. <P>SOLUTION: The reformer 1 of the pyrolysis gas includes a vessel 2 in which the pyrolysis gas obtained by pyrolyzing waste flows and an inflow conduit 3 through which the pyrolysis gas flows into the vessel. A cylindrical nozzle 4 is coaxially provided in the inflow conduit so that the nozzle is located in the connection part of the inflow conduit and the vessel. A space formed by the nozzle and the inflow conduit 3 is used as a pyrolysis gas inflow passage 5. The nozzle 4 is formed by plugging the chip of the conduit provided in a communicatable manner to the supply source of an oxidizing agent gas and has a plurality of jet holes formed in the circumferential part of the chip towards the pyrolysis gas inflow passage. The oxidizing agent gas is jetted from the plurality of jet holes to burn part of the pyrolysis gas. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a pyrolysis gas reformer, and more particularly to a pyrolysis gas reformer suitable for converting high molecular weight hydrocarbons contained in the pyrolysis gas into low molecular weight hydrocarbons or the like.

  As the pyrolysis gas, it is considered to effectively use biomass such as wood chips or pyrolysis gas obtained by pyrolyzing various wastes as fuel gas or raw material gas.

  However, since the waste pyrolysis gas contains various impurities, it cannot be used as it is as a raw material gas for fuel gas or chemical industry, and various methods for purifying the pyrolysis gas have been proposed. In particular, the pyrolysis gas may contain high molecular weight hydrocarbons having 5 or more carbon C (hereinafter collectively referred to as tar), and since tar has a relatively high condensation temperature, it becomes liquid at low temperatures. Become. Since liquid tar causes various problems depending on the use of fuel gas or raw material gas, removal of tar from the pyrolysis gas is required.

  Therefore, Patent Document 1 discloses that in a biomass gasification system, a pyrolysis gas is circulated through a reformer filled with a heat storage body such as a spherical ceramic or a reformer provided with a honeycomb structure heat storage body, It has been proposed to gasify tar into low molecular weight hydrocarbons by heating to 1100 ° C. or higher.

  Patent Document 2 discloses that a pyrolysis gas of combustible waste is introduced into an air blowing reformer (gas cracker) and partially combusted at 1000 to 1200 ° C., and a tar content or a light oil content contained in the pyrolysis gas. Is gasified to low molecular weight hydrocarbons having about 1 to 4 carbon atoms.

JP 2005-60533 A JP 2004-238535 A

  However, according to the technique of Patent Document 1, since the heat storage body is heated by the flame of the burner, temperature non-uniformity occurs depending on the position of the heat storage body. There is a problem that the tar gasification rate (reformation rate) cannot be improved as a whole.

  Further, according to the technique of Patent Document 2, air is blown into the pyrolysis gas in the reformer and partially burned at 1000 to 1200 ° C. to gasify the tar in the pyrolysis gas. Depending on the arrangement and shape of the nozzles, the temperature of the pyrolysis gas in the reformer may not be uniformly high, and there is room for improving the gasification rate of tar.

  The problem to be solved by the present invention is to improve the gasification rate of tar of a reformer that reforms and gasifies the tar by heating the pyrolysis gas to a high temperature.

  In order to solve the above problems, the present invention provides a container in which a pyrolysis gas obtained by pyrolyzing waste is circulated, an inflow conduit through which the pyrolysis gas flows, and the container In the pyrolysis gas reformer having a discharge pipe for discharging the pyrolysis gas from, a cylindrical nozzle is provided coaxially with the inflow pipe, located at a connection portion between the inflow pipe and the container, A space formed by the nozzle and the inflow conduit is a pyrolysis gas inflow passage, and the nozzle is formed by closing a distal end of a conduit provided to be able to communicate with an oxidant gas supply source, It has a plurality of ejection holes formed toward the pyrolysis gas inflow passage at the peripheral edge of the tip, and a part of the pyrolysis gas is burned by ejecting the oxidant gas from the plurality of ejection holes. It is characterized by that.

  As described above, since the oxidant gas is ejected from the plurality of ejection holes formed toward the pyrolysis gas inflow path at the peripheral edge of the nozzle tip, a part of the pyrolysis gas is caused by the ejected oxidant gas. Is burned, tar is effectively gasified in the course of the pyrolysis gas flowing through the combustion flame at a high temperature (for example, 1500 ° C. or higher), and the reformer is heated to a high temperature (for example, 1000 ° C. to 1200 ° C.). The gasification rate of tar can be improved.

  In this case, the plurality of ejection holes at the tip of the nozzle are arranged so that a combustion flame formed by the oxidant gas and the pyrolysis gas ejected from each ejection hole covers a cross section of the pyrolysis gas inflow passage. It is preferable to arrange in. Thereby, since the pyrolysis gas can be circulated through the high-temperature combustion flame formed so as to cover the cross section of the pyrolysis gas inflow passage, tar can be more effectively gasified in the process.

  In particular, it is more preferable that the plurality of ejection holes at the tip of the nozzle are connected to each other and formed into an annular slit. In this case, the nozzle is closed by attaching a conical tip member to the open tip of the nozzle, and a gap formed by the open tip of the nozzle and the tip member is formed in the annular shape. It can be an ejection hole of a slit.

  ADVANTAGE OF THE INVENTION According to this invention, the tar conversion rate of the reformer which heats pyrolysis gas to high temperature and reforms and gasifies tar can be improved.

  Hereinafter, the reformer of the pyrolysis gas of the present invention will be described based on the embodiments.

  FIG. 1 is a cross-sectional configuration diagram of the main part of a reformer 1 for pyrolysis gas according to one embodiment, FIG. 2 is an enlarged view of the part, and FIG. 3 is an overall cross-sectional view of the reformer 1. As shown in these drawings, the reformer 1 includes a container 2 in which a pyrolysis gas obtained by pyrolyzing waste is circulated, and an inflow conduit 3 in which the pyrolysis gas flows into the container 2. The exhaust pipe 9 for discharging the reformed pyrolysis gas from the container 2 is formed. As shown in FIG. 3, the container 2 is formed by applying a fireproof wall 2 b to the inner surface of an iron skin 2 a formed in a cylindrical shape, and an inflow conduit 3 and an exhaust conduit 9 are formed in the same manner. Further, a thermometer T is provided near the outlet of the reformer 1, and temperature control is performed based on this.

  The inflow conduit 3 is connected to the tip of one end of the cylindrical container 2 constricted in a conical cylinder shape so as to coincide with the axis of the container 2. A cylindrical nozzle 4 is provided coaxially in the inflow conduit 3. The tip of the nozzle 4 is disposed at a connection portion that is a boundary between the inflow conduit 3 and the container 2. A space formed in the gap between the inflow conduit 3 and the nozzle 4 is a pyrolysis gas inflow passage 5.

  On the other hand, the nozzle 4 is provided such that one end thereof can communicate with an oxidant gas supply source (not shown). Further, the nozzle 4 is mounted at the tip opening of a cylindrical pipe line with a conical tip member 6 with the tip of the cone facing the inside of the nozzle cylinder, thereby closing the tip opening of the nozzle 4. Yes. An annular slit is formed in the peripheral edge portion of the tip of the nozzle 4, in other words, the outer peripheral surface of the tip member 6, and this slit serves as an oxidant gas ejection hole 7. That is, the ejection hole 7 is formed so as to cover the cross section of the flow path toward the outlet portion of the pyrolysis gas inflow path 5.

Thus, according to the reformer 1 of the present embodiment, the reformer 1 is supplied from a pyrolysis furnace (for example, a rotary drum type pyrolysis kiln) that pyrolyzes waste or the like (not shown). The pyrolysis gas is introduced into the container 2 through the pyrolysis gas channel 5. On the other hand, oxygen O ₂ (or air) is supplied as an oxidant gas from an oxidant supply source (not shown) to the oxidant gas conduit 8 of the nozzle 4 of the reformer 1. The oxidant gas is ejected from the annular ejection hole 7 at the tip of the nozzle to the outlet of the pyrolysis gas flow path 5, and a part of the pyrolysis gas is burned to form a flame 11. Since this combustion flame is a high temperature (for example, 1500 ° C. or higher), the tar in the pyrolysis gas that has come into contact with this combustion flame is immediately gasified and pyrolyzed to produce CO, H ₂ , CO ₂ , C number Converted to low molecular weight hydrocarbons of about 1-4. When steam H ₂ O is jetted together with the oxidant gas, the tar in the pyrolysis gas is modified by an aqueous reaction.

  The pyrolysis gas that has passed through the combustion flame flows through the container 2 held in a high-temperature atmosphere (for example, 1000 ° C. to 1200 ° C.), and the tar in the pyrolysis gas is pyrolyzed to carbonize the low molecular weight. Converted to hydrogen. In addition, the residence time of the pyrolysis gas in the container 2 is set to about 2 to 4 seconds, for example.

  As described above, according to the present embodiment, since the pyrolysis gas is circulated in the high-temperature combustion flame, tar is effectively decomposed and gasified, thereby improving the gasification rate. be able to. In particular, since the high-temperature flame is formed in the entire cross-section of the pyrolysis gas channel 5 by the oxidant gas ejected from the ejection hole 7 formed of the annular slit of the nozzle 4, the pyrolysis gas is evenly distributed. When heated, tar can be effectively decomposed.

  In the above embodiment, the ejection hole 7 formed of an annular slit is used. However, the present invention is not limited to this, and a plurality of ejection holes are provided at the tip of the nozzle 4 toward the flow path cross section of the pyrolysis gas flow path 5. Even if formed, the same effect can be obtained. In this case, it is preferable to narrow the interval between the plurality of ejection holes and form them densely.

The sectional view of the principal part of the reformer of the pyrolysis gas of one embodiment of the present invention is shown. The expanded sectional view of the principal part of embodiment of FIG. 1 is shown. 2 shows an overall cross-sectional view of the reformer of the embodiment of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reformer 2 Container 2a Iron skin 2b Fire wall 3 Inflow line 4 Nozzle 5 Pyrolysis gas flow path 6 Tip member 7 Ejection hole 8 Oxidant gas line

Claims (4)

A container through which pyrolysis gas obtained by pyrolyzing waste is circulated, an inflow pipe through which the pyrolysis gas flows into the container, and a discharge pipe through which the pyrolysis gas is discharged from the container. In a pyrolysis gas reformer having
A cylindrical nozzle is provided coaxially with the inflow conduit located at a connection portion between the inflow conduit and the container, and a space formed by the nozzle and the inflow conduit is a pyrolysis gas inflow passage,
The nozzle is formed by closing a distal end of a pipe line provided to be able to communicate with an oxidant gas supply source, and a plurality of ejection holes formed at a peripheral edge of the distal end toward the pyrolysis gas inflow path And a part of the pyrolysis gas is combusted by ejecting the oxidant gas from the plurality of ejection holes. The reformer of pyrolysis gas according to claim 1,
The plurality of ejection holes at the tip of the nozzle are arranged such that a combustion flame formed by the oxidant gas and the pyrolysis gas ejected from each ejection hole covers a cross section of the pyrolysis gas inflow passage. A pyrolysis gas reformer characterized by comprising: The reformer of pyrolysis gas according to claim 1,
The reformer for pyrolysis gas, wherein the plurality of ejection holes at the tip of the nozzle are connected to each other to form an annular slit. The reformer of pyrolysis gas according to claim 3,
The nozzle is closed by attaching a conical tip member to the open tip of the nozzle, and a gap formed by the open tip of the nozzle and the tip member is inserted into the ejection hole of the annular slit A pyrolysis gas reformer characterized by comprising:

Images