JP2005066484A - Reaction device for organic substance, or the like, by supercritical fluid or subcritical fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reaction device for an organic substance, or the like, by a supercritical fluid, or the like, capable of certainly the sealing supercritical fluid of a high pressure or a subcritical fluid in a cylinder in a reaction engine. <P>SOLUTION: In the reaction engine 2, compression fluid vapor with the substance to be reacted introduced into the cylinder is compressed by operating a compression plunger 4, and after a chemical reaction of the compressed reaction substance to be reacted is completed, the compression plunger 4 is operated in a reverse direction to reduce the temperature and pressure of the fluid vapor, and an intake/exhaust stroke is periodically carried out by removing out the fluid containing the product from the cylinder 3 and blowing-in the fluid vapor into the cylinder. Seal members 15, or the like, are provided on a lower part of a slide surface of the cylinder 3 and the compression plunger 4, and a liquid is poured to a border part 3b formed by the slide surface of the cylinder 3, an outer periphery of the plunger 4 and the both seal members 15, or the like. A liquid press-feed pump 19 for enhancing sealing property and inhibiting abrasion of the slide surface of the cylinder 3 and the sealing member 15, or the like, to a low degree is also provided to the reaction engine 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a reaction apparatus for an organic substance or the like using a supercritical fluid or a subcritical fluid. Specifically, the present invention relates to a reaction apparatus for performing decomposition processing, gasification processing, or the like on an organic substance such as biomass using a supercritical fluid or subcritical fluid as a reaction substance.

  As a treatment method for reactants such as organic substances such as biomass, a method of decomposition with supercritical water or subcritical water has been developed in place of the former chemical oxidation method, photooxidation method and combustion method (patent) Reference 1).

  Furthermore, as a reaction method of an organic substance or the like using a supercritical fluid or a subcritical fluid, for example, supercritical water having a critical condition of water, that is, a critical temperature of 374 ° C. and a critical pressure exceeding 218 atm. And a method of decomposing a reaction substance such as paraffinic hydrocarbon and benzene is also known (Patent Document 2).

In Patent Document 2, for example, a supercritical or subcritical state of fluid vapor is maintained by rapidly compressing a high-pressure fluid in which an organic substance such as wood powder is dispersed in an adiabatic manner and maintaining a supercritical or subcritical state. Discloses a reaction apparatus capable of causing a saccharification reaction of wood flour to sugar by a chemical reaction in That is, means for compressing fluid vapor to obtain a supercritical fluid or subcritical fluid, means for bringing the supercritical fluid or subcritical fluid into contact with a reactant such as an organic substance, and performing a chemical reaction, and this chemical reaction And a means for expanding and cooling the fluid containing the product generated by the above. And as the means, although fluid vapor | steam is compressed with a cylinder and the compression plunger provided in this cylinder, the method of sealing the high voltage | pressure in that case is not described at all.
Japanese Patent Publication No. 1-38532 JP 2002-263465 A

  In a reactor for handling a supercritical state or subcritical state of a high-temperature, high-pressure fluid that can efficiently implement a reactor such as an organic substance using a supercritical fluid or a subcritical fluid as in Patent Document 2, a high temperature, high pressure As a method of sealing the boundary surface between the cylinder and the compression plunger provided in the cylinder, a supercritical fluid or a subcritical fluid was used in a plurality of ring configurations found in conventional internal combustion engines and compressors. In the sealing method, since the lubricating oil on the cylinder sliding surface is cleaned by the cleaning action by steam, high sealing performance cannot be secured.

  In view of this, the present invention provides a reaction apparatus for an organic substance or the like using a supercritical fluid or subcritical fluid that can reliably seal a high-temperature, high-pressure supercritical fluid or subcritical fluid in a cylinder in a reaction engine. Aimed at that.

  In order to achieve the above-described object, a reaction device for organic substances or the like using a supercritical fluid or a subcritical fluid according to the present invention comprises a cylinder and a compression plunger provided in the cylinder. After compressing the fluid vapor with the reactants introduced into the reactor, the chemical reaction of the reactants due to this compression is completed, the plunger is operated in the reverse direction to lower the temperature and pressure of the fluid vapor, and the product obtained In a reaction engine that periodically performs an intake and exhaust stroke by taking out a fluid containing the inside of the cylinder and blowing new fluid vapor into the cylinder, a ring or the like is formed on the lower part of the sliding surface of the cylinder and the upper part of the compression plunger. One or more sealing members such as a gland packing having no joint portion are provided, and the cylinder sliding surface and the plunger Liquid for injecting liquid through the check valve to the outer periphery and the boundary formed by the both seal members to improve the sealing performance of the seal member and to keep the wear of the sliding surface of the cylinder and the seal member low It is characterized by the fact that the introduction mechanism is attached to the reaction engine.

  Since the volume of the boundary in the reaction engine of the present invention described above changes greatly due to the vertical movement of the plunger, the boundary filled with the injected incompressible liquid becomes extremely high pressure, and the seal member Or pass through the seal member and flow into the reaction chamber, the pressure in the reaction chamber is changed, and a stable supercritical or subcritical state cannot be secured.

  Further, if the amount of liquid held in the boundary portion including the outflow from the lower portion of the cylinder is insufficient, the sealing performance of the sealing member is reduced and the wear is increased, so that a stable reaction cannot be maintained. That is, the pressure control of the liquid at the boundary becomes a problem. However, since the liquid is generally an incompressible liquid, the pressure control of the liquid can be rephrased as volume control.

  Therefore, the maximum amount of change in the volume of the boundary due to the vertical movement of the plunger and the amount of leakage from the seal member are set to an amount sufficient to replenish the liquid introduction path to be injected into the boundary, and the vertical movement of the plunger By discharging and sucking in synchronism, the volume of the liquid introduction part is kept substantially constant, thereby preventing an abnormal pressure increase at the boundary when the plunger is lowered and preventing the pressure from being applied to the boundary when the plunger is raised. A volume balance type pressure pump for supplying liquid is provided.

  Further, in response to the above-mentioned problem in the reaction engine of the present invention, as an alternative to the volume balance type pressure delivery pump, the plunger is not actively discharged / inhaled like the volume balance type pressure delivery pump. A pressure accumulating chamber whose volume is changed by pressure is provided in the liquid introduction path by utilizing the pressure fluctuation of the boundary generated by the vertical movement, and the volume of the accumulating chamber is increased at a high pressure to respond to the pressure drop of the boundary. A pressure accumulation chamber is provided in which the sum of the volume of the boundary portion and the pressure accumulation chamber is made substantially constant by reducing the volume of the pressure accumulation chamber.

  Further, as another solution to the above-described problem of the present invention, a path that communicates the reaction part and the boundary part via a movable piston that separates the compressed vapor in the reaction chamber and the liquid in the boundary part is provided. By providing, the pressure in the reaction chamber and the boundary portion is made substantially the same.

  Since the present invention is configured as described above, the following effects are exhibited.

  In the reaction apparatus of the present invention, by providing a seal member such as a gland packing at the bottom of the cylinder, a liquid introduction mechanism such as a liquid introduction pump is attached to the reaction engine at the sliding portion of the compression plunger in the cylinder, By injecting this liquid introduction mechanism in synchronism with the supercritical fluid or subcritical fluid in the cylinder, the supercritical fluid or subcritical fluid can be reliably sealed in the sliding portion of the cylinder.

  In the liquid introduction mechanism, the discharge amount of the pressure pump is generally set to an amount sufficient to replenish the volume change amount of the boundary portion due to the vertical movement of the compression plunger and the leakage amount from the seal member. By discharging and sucking in synchronism with the vertical movement and keeping the volume of the liquid introduction part substantially constant, the abnormal pressure rise of the boundary part when the compression plunger is lowered and the boundary part when the compression plunger is raised are prevented. Thus, the amount and pressure of the liquid at the boundary can be properly maintained.

  Further, a pressure accumulator that absorbs a pressure change accompanying a volume change of the boundary due to a vertical movement of the compression plunger in a path for injecting a high-pressure liquid into a boundary formed by the cylinder and the compression plunger by the liquid introduction mechanism. By providing, extreme pressure rise and pressure drop can be prevented.

  In the pressure accumulator that absorbs the pressure change accompanying the volume change of the boundary formed by the cylinder and the compression plunger due to the vertical movement of the compression plunger, the opposite side of the movable piston of the pressure accumulation chamber is communicated with the reaction chamber, whereby the compression An increase in pressure in the cylinder during the compression stroke of the plunger increases the pressure of the liquid at the boundary via the movable piston, and conversely, a decrease in pressure in the cylinder when the compression plunger moves down is via the movable piston. By providing a pressure propagation mechanism that lowers the pressure at the boundary, the pressure in the reaction chamber is tracked and the liquid pressure at the boundary is maintained. Inflow of fluid is reliably prevented, and the pressure in the reaction chamber is transmitted to a seal member provided at the lower part of the cylinder, so that reliable sealing with liquid is possible.

  In addition, by setting the sealing performance of the upper sealing member higher than the sealing performance of the lower sealing member by setting the number of sealing members, the tightening allowance, etc. in both sealing members provided at the lower part of the cylinder and the upper part of the compression plunger, It is possible to cause leakage from the seal member due to pressure fluctuation at the boundary due to the vertical movement of the plunger on the lower seal side.

  In addition to the boundary sealing member provided at the lower part of the cylinder, one or more sealing members such as a gland packing are provided on the piston side for driving the compression plunger, and a lantern ring or the like is provided between the sealing members therebetween. It is possible to avoid mixing these liquids and water vapor by introducing liquid leakage from the compression plunger side or oil leakage from the piston side to the outside. Thereby, the supercritical state or subcritical state in the cylinder can be stabilized, and the reaction engine can be operated efficiently.

  Next, the best mode for carrying out the invention will be described with reference to the drawings. The reaction engine 2 is shown in FIG. 1 in the configuration of the reaction apparatus 1 for an organic substance or the like using a supercritical fluid or a subcritical fluid according to the present invention. Note that illustrations of a steam generator, a condenser for collecting reaction products, and the like are omitted. In the reactor 1, as a fluid for obtaining a supercritical fluid or subcritical fluid, in addition to water, for example, carbon dioxide, nitrous oxide, freon 12, freon 13, ethane, ethylene, propylene, butane, hexane, methanol, benzene, Toluene, ammonia, and other various substances can be selected and used, but the following will be described in the case of water.

  The reaction apparatus 1 is provided with a reaction engine 2 including a cylinder 3 and a compression plunger 4 that moves up and down in the cylinder 3. The compression plunger 4 is a broad concept including biston.

  In the reaction engine 2, the cylinder 3 is supported by a block 21, and the compression plunger 4 is fastened so as to be driven by a driving piston 4 b in the block 21. The driving piston 4b periodically moves up and down by the crankshaft 22 through the connecting rod 23 and the piston pin 4c.

  By operating the compression plunger 4 in the reaction engine 2, it is possible to introduce water vapor from the boiler 5 provided in the reaction apparatus 1, and to compress the water vapor to obtain supercritical water or subcritical water. A reactant is brought into contact with the supercritical or subcritical water vapor to cause a chemical reaction in the reactant. Next, after the chemical reaction of the reactant is completed, the compression plunger 4 is operated in the reverse direction to lower the temperature and pressure of the supercritical water or the subcritical water to obtain steam. Remove from the cylinder. Again, the water vapor is blown into the cylinder 3 by operating the compression plunger 4 in the same manner as described above. In the reaction engine 2, such an intake / exhaust stroke can be periodically operated.

  The reaction chamber 6 includes a space formed by a sliding surface of the cylinder 3, a top surface 4 a of the compression plunger, and a head 10 fastened to the upper portion of the cylinder 3. In addition, an intake valve 7 for sucking steam from the boiler 5 and an exhaust valve 8 for discharging steam in the reaction chamber 6 are provided on the surface of the reaction chamber 6 of the head 10 forming the reaction chamber 6, respectively. It is guided to the outside of the reaction engine 2 through the intake port 9a and the exhaust port 9b.

  Opening and closing of the intake valve 7 and the exhaust valve 8 is driven in the vertical direction via a tappet 14 driven by a cam shaft (not shown). The intake valve 7 and the exhaust valve 8 are urged so as to be always closed by a spring (not shown).

  The head 10 is provided with a raw material introduction hole 16 that communicates with the reaction chamber 6 and introduces the raw material substantially in synchronism with the opening timing of the intake valve to improve mixing with the vapor.

  Since the steam sucked into the cylinder 3 from the suction valve 7 is compressed to a high pressure by the compression plunger 4, a sufficient sealing property is required. However, with the sealing method that relies on the viscosity of the lubricating oil in a plurality of ring configurations used in conventional internal combustion engines, compressors, etc., the lubricating oil can be held at the abutment of the ring by the cleaning action of steam. Therefore, it is not possible to ensure a sealing property that can withstand a sufficient high pressure.

  Therefore, in order to ensure the sealing performance of the sliding portion, one or a plurality of sealing members 15 and 18 having no joint portion such as a gland packing are provided on the lower portion of the sliding surface of the cylinder 3 and the upper portion of the compression plunger 4. Liquid such as water or lubricating oil is supplied from the introduction hole 20a provided in the lower portion of the cylinder 3 to the boundary 3b formed by the sliding surface of the cylinder 3, the outer peripheral surface of the compression plunger 4, and both seal members. Inject. Of course, in order to seal the high pressure in the reaction chamber 6, the pressure in the boundary portion 3 b becomes the maximum pressure in the reaction chamber 6, so a check valve 24 is provided between the boundary portion 3 b and the liquid pumping pump 19. . As a result, the sealing performance of both the sealing members 15 and 18 is enhanced, and the abnormal sliding of the sliding surface of the cylinder 3 and the sealing members 15 and 18 is prevented, thereby ensuring a stable sealing performance over a long period of time. In particular, in this sealing method, the pressure difference between the reaction chamber 6 and the boundary portion 3b can be reduced, so that the burden on the seal member 18 provided on the upper portion of the compression plunger 4 can be kept low. This makes it possible to ensure a stable supercritical state over a long period of time.

  However, although the volume of the boundary portion 3b greatly changes due to the vertical movement of the compression plunger 4, the liquid injected into the boundary portion 3b is almost incompressible. Therefore, if the sealing member seals completely, the compression plunger 4 When descending, the pressure at the boundary portion 3b becomes extremely high, and there is a concern that the liquid may flow out exceeding the limit of the sealing performance of the upper and lower sealing members 15 and 18, or the sealing member may be damaged. However, in general, a sealing member typified by a gland packing or the like produces a sealing property by pressure loss due to leakage, and thus it is necessary to seal a high pressure while replenishing the leakage. Although the pressure change at the boundary 3b varies depending on the rotation speed and stroke, that is, the speed of the compression plunger 4, it is more effective to positively control the pressure at the boundary 3b.

  Therefore, as shown in FIG. 2, the amount of leakage from the seal members 15 and 18 is replenished to the maximum volume of the boundary portion 3b between the boundary portion 3b of the path for injecting liquid into the boundary portion 3b and the check valve 24. (When the pressure of the boundary portion 3b is high, the check valve 24 provided after the pump 19 remains closed and the tank 25 is discharged from the tank 25). No new liquid is sucked), and the liquid is fed at a timing when the volume of the boundary portion 3b is increased by discharging the compression plunger 4 when it rises. That is, by providing the volume balance type pumping pump 26 synchronized with the compression plunger 4, the sum of the volume of the boundary portion 3b and the compression volume 29 of the volume balance type pumping pump 26 is always substantially constant. It prevents the decline.

  Next, FIG. 2 proposes a method in which the volume change of the boundary 3b is positively absorbed by the volume balance type pump 26, but in FIG. 3, the pressure change of the boundary 3b is used to give the volume change. The pressure accumulating chamber 30 is provided in place of the volume balance type pressure pump 26. The shortage of liquid due to leakage from the seal members 15 and 18 is caused through the check valve 24 when the pressure in the path between the boundary portion 3b and the pressure accumulating chamber 30 falls below a certain pressure by the pump 19 that pumps the liquid at a certain pressure. The supply is common to all systems.

  Next, what is proposed in FIG. 4 is to control the pressure of the boundary portion 3b by using the pressure in the reaction chamber 6, and reacts on the opposite side of the movable piston 31 of the pressure accumulating chamber 30 proposed in FIG. The pressure of the chamber 6 is supplied. That is, a pressure balance mechanism that balances the pressures on both surfaces is provided via the movable piston 33 that separates the compressed vapor in the reaction chamber 6 and the liquid in the boundary portion 3b. For example, in the process of compressing the intake steam, the compression plunger 4 rises and the pressure in the reaction chamber 6 rises, but the volume of the boundary portion 3b increases, so the pressure drops. Therefore, the pressure in the reaction chamber 6 is transmitted to the upper surface 34b of the movable piston 33 via the path 20b, and the lower pressure 34a of the movable piston 33 is transmitted to the lower surface 34a. Move to increase the pressure on the boundary 3b side. In this method, the pressure difference between the upper and lower sides of the seal member 18 provided on the upper portion of the compression plunger 4 can be kept extremely small.

  Thus, in the present invention, the sealing member 18 provided at the upper portion of the compression plunger 4 is not intended to seal the high pressure in the reaction chamber 6, but the liquid injected into the boundary portion 3 b flows out into the reaction chamber 6. The main purpose is to prevent. The high pressure in the reaction chamber 6 is sealed by a seal member 15 provided at the lower part of the sliding surface of the cylinder 3. In this case, the purpose of the liquid in the boundary portion 3 b is to transmit the pressure in the reaction chamber 6 to the seal member 15 provided in the lower portion of the cylinder 3 and to improve the sealing performance of the seal member 15. In other words, since the sealing member has a sealing property due to pressure loss due to leakage, a sufficient amount of fluid that leaks during high pressure action is necessary.

  In any of the sealing methods proposed in the present invention, the pressure difference acting on the seal member 18 provided on the upper portion of the compression plunger 4 is smaller than the pressure difference acting on the seal member 15 provided on the lower portion of the cylinder 3. 4 is more advantageous from the viewpoint of durability. However, since the outflow of liquid into the reaction chamber 6 cannot secure a stable supercritical water reaction, the number and length of the seal members are long. Furthermore, the sealing member 18 at the upper part of the compression plunger 4 is set more firmly than the sealing member 15 provided at the lower part of the cylinder 3 by tightening allowance or the like.

  Further, in the present reaction engine 2, since the compression plunger 4 is fastened to the drive piston 4b, the leakage of water vapor from the seal member 15 provided at the lower portion of the cylinder 3 is a cause of seizure of the sliding surface of the drive piston 4b. At the same time, it should be avoided that the lubricating oil scooped up by the drive piston 4b is mixed into the liquid of the boundary portion 3b in consideration of a long-term operation. As shown in FIG. A seal member 15c for sealing lubricating oil from the drive piston 4b side is further provided below 15a and 15b, and a lantern ring 35 and the like are inserted between the sealing member 15c and the leaked liquid and lubricating oil are discharged to the outside. Hole 36 is provided.

  Since this sealing method does not depend greatly on the viscosity or the like of the liquid, it is possible to select the liquid injected into the boundary surface 3b that is less affected by the type of supercritical fluid or the reaction process.

It is a fragmentary longitudinal cross-sectional view of the reaction apparatus of the organic substance etc. by the supercritical fluid or subcritical fluid of the best form which concerns on this invention. It is a fragmentary longitudinal cross-section explaining the system absorbed by the volume balance type pressure pump in the reaction apparatus of the organic substance etc. by the supercritical fluid or subcritical fluid of the best form which concerns on this invention. It is a fragmentary longitudinal cross-section explaining the form which provided the pressure accumulation chamber in the reactor of the organic substance etc. by the supercritical fluid or subcritical fluid of the best form which concerns on this invention. It is a fragmentary longitudinal cross-section explaining the form of the sliding part of the cylinder in the reaction apparatus of the organic substance etc. by the supercritical fluid or subcritical fluid of the best form which concerns on this invention. It is a fragmentary longitudinal cross-section explaining the form of the sliding part of the cylinder in the reaction apparatus of the organic substance etc. by the supercritical fluid or subcritical fluid of the best form which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reaction apparatus 2 Reaction engine 3 Cylinder 3a Sliding surface 3b Boundary part 4 Compression plunger 4a Compression plunger top surface 4b Driving piston 4c Piston pin 5 Boiler 6 Reaction chamber 7 Intake valve 8 Exhaust valve 9a Intake port 9b Exhaust port 10 Head 11 Intake hole 12 Exhaust hole 13 Valve shaft 14 Tappet 15 Seal members 15a to 15c Seal member 16 Raw material material introduction hole 18 Seal member 19 Liquid pressure pump 20a Introduction hole 20b Path 21 Block 22 Crankshaft 23 Connecting rod 24 Check valve 25 Tank 26 Volume balanced pump 27 Plunger (piston)
28 Cam shaft 29 Compression volume 30 Accumulated chamber 31 Movable piston 31a Spring 32 Pressure balance mechanism 33 Movable piston 33a, 33b Spring 34a Lower surface 34b Upper surface 35 Lantern ring 36 Discharge hole 37 Seal member presser

Claims (6)

  It consists of a cylinder and a compression plunger provided in the cylinder, and by operating the compression plunger, the fluid vapor with the reactant introduced into the cylinder is compressed, and after the chemical reaction of the reactant by this compression is completed The compression plunger is operated in the opposite direction to lower the temperature and pressure of the fluid vapor, the fluid containing the obtained product is taken out from the cylinder, and new fluid vapor is blown into the cylinder to periodically perform the intake and exhaust strokes. In the reaction engine to be performed, one or a plurality of seal members that do not have a joint gap in a piston ring or the like such as a gland packing are provided at the lower part of the sliding surface of the cylinder and the upper part of the compression plunger, and are sandwiched between the two seal members. A liquid such as water or oil can be injected into a boundary formed by the sliding surface of the cylinder and the outer peripheral surface of the plunger. Reactor, such as an organic substance by supercritical fluid or subcritical fluid, characterized in that features a liquid introduction mechanism having.   In the liquid introduction mechanism for injecting the liquid into the boundary portion, the discharge amount of the pressure pump is generally sufficient to replenish the amount of change in the volume of the boundary portion due to the vertical movement of the plunger and the leakage amount from the seal member. In addition, the discharge and suction are performed in synchronization with the vertical movement of the plunger, and the volume of the liquid introduction portion is kept substantially constant, thereby preventing an abnormal pressure increase at the boundary when the plunger is lowered, The organic material or the like by supercritical fluid or subcritical fluid according to claim 1, wherein a negative pressure at the boundary portion during rising is avoided and the amount and pressure of the liquid at the boundary portion are appropriately maintained. Reactor.   A pump for supplying liquid at a constant pressure via a check valve is provided in the path for injecting high-pressure liquid into the boundary formed by the cylinder and the plunger by the liquid introduction mechanism, and the plunger is moved up and down. 3. A reaction apparatus for an organic substance or the like using a supercritical fluid or a subcritical fluid according to claim 1 or 2, further comprising a pressure accumulating device that absorbs a pressure change caused by a volume change in the boundary portion.   By communicating the opposite side of the movable piston of the pressure accumulating chamber with the reaction chamber in the pressure accumulating device that absorbs the pressure change accompanying the volume change of the boundary portion formed by the cylinder and the plunger due to the vertical movement of the plunger, The increase in pressure in the cylinder during the compression-up stroke of the plunger increases the pressure of the liquid at the boundary via the movable piston, and conversely, the decrease in pressure in the cylinder when the plunger moves down is via the movable piston. 3. A reaction apparatus for an organic substance or the like using a supercritical fluid or a subcritical fluid according to claim 1 or 2, further comprising a pressure propagation mechanism that lowers the pressure at the boundary.   The sealing performance of the upper sealing member is set to be higher than the sealing performance of the lower sealing member by setting the number of sealing members, the tightening allowance, and the like in both sealing members provided at the lower portion of the cylinder and the upper portion of the plunger. 5. The liquid according to claim 1, wherein leakage from the seal member due to pressure fluctuation at the boundary due to movement is caused on the lower seal side to prevent liquid from flowing into the reaction chamber. Reactors for organic substances using supercritical fluids or subcritical fluids.   In addition to the boundary sealing member provided at the lower part of the cylinder, one or a plurality of sealing members such as a gland packing are provided on the piston side for driving the plunger, and a lantern ring or the like is provided between the sealing members therebetween. The supercritical fluid according to any one of claims 1 to 5, wherein mixing is avoided by introducing a liquid leakage from the plunger side or oil leakage from the piston side to the outside. Or a reaction device for organic substances by subcritical fluid.