JP2014189590A - Biomass supercritical water gasification system with activated carbon operation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that can, at the start-up of a biomass supercritical water gasification system with activated carbon, suppress the decrease in concentration of activated carbon in suspension liquid, which was fed to the system, containing activated carbon suspended in water-retaining biomass, and prevent the blockage of apparatus due to tar or the like, as well as that can efficiently carry out the biomass supercritical water gasification with activated carbon.SOLUTION: In a supercritical water gasification system comprising: a reactor 50 for gasifying biomass with supercritical water using activated carbon suspended in suspension liquid as a catalyst; a separator 60 for separating a mixture containing formation gas and the like formed in the reactor 50 into gas component and liquid component; a heat exchanger 30 for pre-heating suspension liquid to be treated in the reactor 50 using the heat of the mixture discharged from the reactor 50; and a pre-heater 40 for pre-heating the suspension liquid fed to the reactor 50, an activated carbon suspended water is fed to the system in advance before feeding an activated carbon, which is a gasification catalyst, suspended gasification raw material to the system, is started.

Description

  The present invention relates to a method capable of efficiently performing supercritical water gasification of biomass with activated carbon.

  Conventionally, in a technology that gasifies hydrous biomass (shochu residue, egg-laying chicken manure, etc.) with supercritical water, a suspension of activated carbon suspended in hydrous biomass is hydrothermally treated with a pretreatment device to make the biomass slurry. Then, in the supercritical water gasification reactor, the activated carbon suspended in the liquefied material obtained by treating the suspension with hot water is used as a catalyst to treat the slurry with supercritical water. A system has been developed that separates the generated product gas and ash, and the mixture in which the nonmetallic catalyst is suspended in water, into gas components such as product gas and liquid components such as ash, activated carbon and water ( For example, see Patent Documents 1 and 2).

JP 2010-174190 A JP 2010-172859 A

However, in the above-described system, even when a predetermined time elapses after the operation of the system, that is, the biomass is processed and liquid components such as ash, activated carbon, and water are discharged after starting the supply of the suspension, Since the activated carbon is hardly suspended in the liquid component and activated carbon is suspended in the liquid component after a few hours, the amount of activated carbon is suspended. At the start of operation (from the start of operation of the system until the drainage liquid in which the same amount of activated carbon as the suspension is suspended is discharged as a liquid component), the activated carbon supplied to the system, that is, water content Since activated carbon suspended in water-soluble biomass cannot be used effectively, tar and the like may be generated, causing pipe clogging.
Also, when activated carbon equivalent to the amount supplied to the system is suspended in the liquid component, the activated carbon and ash removed from the liquid component are transparent, but the activated carbon is almost suspended. The activated carbon and ash removed from the liquid components are not cloudy or yellowish, have a tar odor, and the formation of clogging substances such as tar can be confirmed. It is considered that the amount of activated carbon supplied to the supercritical water gasification reactor is reduced compared to the amount of the above, affecting the gasification reaction by supercritical water, and clogging substances such as tar are generated.
The present invention has been made in view of the above problems, and activated carbon in a suspension obtained by suspending activated carbon in hydrous biomass supplied to the system at the start of operation of a biomass supercritical water gasification system using activated carbon. An object of the present invention is to provide a method capable of preventing the apparatus from being clogged with tar or the like while suppressing a decrease in the concentration of the biomass and efficiently performing supercritical water gasification of biomass with activated carbon.

  As a result of earnest research to solve the above problems, the present inventors suspended activated carbon before starting the feeding of the gasification raw material in which activated carbon as a gasification catalyst was suspended in the system. By supplying water in advance, compared to the case of not supplying water in which activated carbon is suspended in advance, the above-described gasification raw material suspension in which activated carbon that is a gasification catalyst is suspended is sent to the system. The same amount of activated carbon suspended in a suspension of activated carbon suspended in biomass supplied to the system is discharged as a liquid component early, that is, at the start of system operation, the system This prevents the concentration of activated carbon in the suspension supplied to the reactor from decreasing and prevents clogging of the equipment upstream of the supercritical water gasification reactor due to tar, etc. It found that it is possible to perform stably and efficiency of, and have completed the present invention.

  That is, the operation method of the supercritical water gasification system according to the present invention is a gasification treatment of the biomass with supercritical water using the activated carbon suspended in a suspension of activated carbon suspended in hydrous biomass as a catalyst. A gasification reactor, a product gas and ash produced in the gasification reactor, and a mixture in which the activated carbon is suspended in water, a gas component containing the product gas, and an ash and activated carbon suspended in water. The gas-liquid separator that separates into a turbid liquid component, and the suspension that is gasified with supercritical water in the gasification reactor using the heat of the mixture discharged from the gasification reactor. In the supercritical water gasification system comprising: a heat exchanger that preheats a suspension; and a preheater that preheats the suspension supplied from the heat exchanger to the gasification reactor. To be a gasification catalyst Before supplying the gasification raw material in which charcoal is suspended and supplying the suspension to each device in the supercritical water gasification system, water in which activated carbon is suspended is supplied in advance. It is characterized by. The water in which the activated carbon is suspended is supplied to the supercritical water gasification system by suspending the activated carbon having the same concentration as the water in which the activated carbon is suspended by the gas-liquid separator. You may carry out until it isolate | separates as a liquid component and is discharged | emitted.

  According to the present invention, at the start of operation of the supercritical water gasification system for biomass with activated carbon, the decrease in the concentration of activated carbon in the suspension in which activated carbon is suspended in hydrous biomass supplied to the system is suppressed, It is possible to provide a method capable of preventing the clogging of the apparatus due to tar or the like and efficiently performing supercritical water gasification of biomass with activated carbon.

In one Embodiment of this invention, it is a figure which shows schematic structure of the supercritical water gasification system of the biomass by activated carbon.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The objects, features, advantages, and ideas of the present invention will be apparent to those skilled in the art from the description of the present specification, and those skilled in the art can easily reproduce the present invention from the description of the present specification. it can. DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and drawings of the invention described below show preferred embodiments of the present invention and are shown for illustration or explanation, and are not intended to limit the present invention thereto. Absent. It will be apparent to those skilled in the art that various modifications can be made based on the description of the present specification within the spirit and scope of the present invention disclosed herein.

== Configuration of biomass supercritical water gasification system using activated carbon ==
FIG. 1 is a diagram showing a schematic configuration of a biomass supercritical water gasification system using activated carbon (hereinafter simply referred to as “system”), which is described as one embodiment of the present invention. As shown in FIG. 1, the system 100 includes a regulating tank 1, a crusher 2, a supply pump 3, a heat exchanger 30, a preheater 40, a gasification reactor 50, a cooler 51, a decompressor 52, and a gas-liquid separator. 60, gas tank 61, heaters 62, 63, and the like, supply pump 3 and slurry supply device 21, slurry supply device 21 and heat exchanger 30, heat exchanger 30 and preheater 40, preheater 40 and gasification The reactor 50, the gasification reactor 50 and the heat exchanger 30, the heat exchanger 30 and the cooler 51, the cooler 51 and the decompressor 52, and the decompressor 52 and the gas-liquid separator 60 are connected by piping. Yes.

  The adjustment tank 1 is a tank that mixes hydrous biomass, activated carbon, water, and the like. Before starting to feed the gasification raw material in which activated carbon, which is a gasification catalyst, is suspended in the system 100, the water and activated carbon that have been added are mixed to suspend the activated carbon in water, and the gasification catalyst is added to the system 100 When the liquid feed of the gasification raw material in which the activated carbon is suspended is started, the supplied hydrous biomass and activated carbon, and the supplied water as necessary are mixed into the hydrous biomass (or biomass solution). Activated carbon is suspended to prepare a gasification raw material (suspension). In addition, the input of water is performed according to the moisture content of biomass. The hydrous biomass is, for example, shochu residue, egg-collected chicken droppings, sludge, and the like. Moreover, as said activated carbon, it is preferable to use the particle | grains with an average particle diameter of 200 micrometers or less, and it is more preferable to use the porous particle | grains with an average particle diameter of 200 micrometers or less.

  The crusher 2 crushes the biomass in the suspension suspended in the adjustment tank 1 so as to have a uniform size in advance (preferably an average particle size of 500 μm or less, more preferably an average particle size of 300 μm or less). It is a device for.

  The gasification reactor 50 is an apparatus that gasifies the biomass in the suspension with supercritical water using the activated carbon suspended in the suspension in which the biomass is crushed by the crusher 2 as a catalyst. Biomass gasification with supercritical water is performed by hydrothermally treating the biomass under the conditions of a temperature of 374 ° C. or higher and a pressure of 22.1 MPa or higher using the activated carbon. By treating the biomass with supercritical water in this way, the biomass can be decomposed and a fuel gas such as hydrogen gas, methane, ethane, or ethylene can be generated.

  The supply pump 3 is a device that supplies the gasification reactor 50 with a suspension obtained by crushing biomass with the crusher 2. The supply pump 3 is not particularly limited as long as it is a device that can supply a suspension obtained by crushing biomass. For example, a high-pressure pump or a Mono pump can be used.

  In the heat exchanger 30, product gas and ash generated by gasification with supercritical water in the gasification reactor 50 and activated carbon are suspended in water and discharged from the gasification reactor 50. This is an apparatus for preheating a suspension obtained by pulverizing biomass that is gasified by supercritical water in the gasification reactor 50 using the heat of the discharge (mixture).

The preheater 40 is a device that preheats a suspension obtained by crushing biomass supplied from the heat exchanger 30 to the gasification reactor 50 to a predetermined temperature.
The cooler 51 is a device for cooling the discharge (the product gas, ash and activated carbon suspended in water) discharged from the gasification reactor 50. The cooler 51 is, for example, a cooler.
The decompressor 52 is a device that reduces the pressure of the exhaust discharged from the gasification reactor 50.

The gas-liquid separator 60 is an apparatus that separates the exhaust discharged from the gasification reactor 50 into a gas component containing a product gas (fuel gas or the like) and a liquid component in which ash and activated carbon are suspended in water. It is.
The gas tank 61 is a container (preferably a pressure resistant container) that stores the gas component (product gas) separated by the gas-liquid separator 60.

  The heater 62 burns a part of the generated gas (fuel gas) stored in the gas tank 61 or fuel gas (for example, LPG) to heat the gasification reactor 50, and the suspension obtained by pulverizing the biomass is heated. It is an apparatus for heating to a predetermined temperature. The heater 63 burns a part of the generated gas (fuel gas) stored in the gas tank 61 or a fuel gas (for example, LPG) to heat the preheater 40, and the suspension obtained by pulverizing the biomass is heated. It is an apparatus for heating to a predetermined temperature.

In the present embodiment, the heat exchanger that heats the suspension obtained by pulverizing the biomass using the heat of the exhaust gas obtained by burning the produced gas in the gas tank 61 by the heater 63 is gasified. It is provided in the reactor 50.
The heaters 62 and 63 are existing devices that burn and heat fuel gas, such as a burner, for example.

  In the present embodiment, in the adjustment tank 1, a suspension in which activated carbon is suspended in hydrous biomass (or a solution of biomass) or water in which activated carbon is suspended is heat-exchanged by the supply pump 3. The activated carbon is suspended in the hydrous biomass (or biomass solution) crushed by the crusher 2 or suspended in water immediately before being supplied by the supply pump 3. 30 may be supplied.

  Further, in the present embodiment, in one adjustment tank 1, a suspension in which activated carbon is suspended in hydrous biomass (biomass solution) and water in which activated carbon is suspended are prepared. However, you may each provide the adjustment tank which prepares separately the suspension which activated carbon suspended in the hydrous biomass, and the water which suspended activated carbon. In this case, the water in which the activated carbon is suspended prepared by the adjustment tank may be supplied to the heat exchanger 30 not by the crusher 2 but by the supply pump 3 or another supply pump.

== Operation method of supercritical water gasification system of biomass using activated carbon ==
Next, although the operation method of the system 100 will be described below with an example, the method of the present invention is not limited to the following method.
When the feeding of the gasification raw material in which activated carbon, which is a gasification catalyst, is suspended to the system 100, activated carbon, biomass, and water as necessary are charged into the system 100, more specifically, the adjustment tank 1. Thus, a suspension adjusted to a predetermined moisture content and a predetermined activated carbon concentration (wt%) is prepared. Thereafter, the suspension biomass is crushed by the crusher 2, and the suspension in which the biomass is crushed is supplied to the preheater 40 via the heat exchanger 30 by the supply pump 3 and preheated. In the gasification reactor 50, the activated carbon suspended in the suspension is used as a catalyst for gasification with supercritical water. The product gas and ash generated in the gasification reactor 50 are discharged from the gasification reactor 50 together with activated carbon and water as an exhaust, and heat is supplied to the suspension in which the biomass supplied to the heat exchanger 30 is crushed. Provided, and cooled and decompressed by the cooler 51 and the decompressor 52. The cooled and decompressed exhaust gas (mixture) is separated into a gas component containing the generated gas and a liquid component in which ash and activated carbon are suspended in water by the gas-liquid separator 60, and the generated gas is stored in the gas tank 61. And the liquid component is discharged.

  In the present embodiment, before starting the feeding of the gasification raw material in which the activated carbon as the gasification catalyst is suspended to the system 100, the water in which the activated carbon is suspended (which does not include biomass). Are supplied in advance to each device 30, 40, 50, 51, 52, 60 downstream of the supply pump 3 in the system 100 by each device in the system 100, more specifically, the supply pump 3. In addition, the water in which the activated carbon is suspended is supplied by separating the water in which activated carbon having the same concentration as the suspended water in the activated carbon is separated as a liquid component by the gas-liquid separator. It is preferable to carry out until Further, the concentration of the activated carbon suspended in water is required in large quantities as the scale of the system 100 and the respective devices 30, 40, 50, 51, 52, and 60 is increased. Particularly preferred. In this way, before starting the feeding of the gasification raw material in which the activated carbon as the gasification catalyst is suspended to the system 100, the water in which the activated carbon is suspended is supplied in advance, so that the operation of the system 100 is started. In this case, the concentration of activated carbon in the suspension supplied to the system 100 can be suppressed from decreasing, and the apparatus upstream of the gasification reactor 50 can be prevented from being blocked by tar or the like. Moreover, since the production | generation of obstruction | occlusion substances, such as tar by lack of activated carbon, can be suppressed, it becomes possible to perform the supercritical water gasification reaction of the biomass by activated carbon in the gasification reactor 50 efficiently.

1 adjustment tank, 2 crusher, 3 feed pump, 30 heat exchanger, 40 preheater, 50 gasification reactor, 51 cooler, 52 decompressor, 60 gas-liquid separator, 61 gas tank, 62, 63 heater, 100 Supercritical water gasification system of biomass using activated carbon

Claims (2)

A gasification reactor for gasifying the biomass with supercritical water using the activated carbon suspended in a suspension of activated carbon in a hydrous biomass as a catalyst;
The product gas and ash produced in the gasification reactor, and the mixture in which the activated carbon is suspended in water are converted into a gas component containing the produced gas and a liquid component in which the ash and activated carbon are suspended in water. A gas-liquid separator to be separated;
A heat exchanger for preheating the suspension gasified by supercritical water in the gasification reactor using heat of the mixture discharged from the gasification reactor;
A preheater for preheating the suspension supplied from the heat exchanger to the gasification reactor;
In a supercritical water gasification system comprising:
Before feeding the gasification raw material in which activated carbon as a gasification catalyst is suspended to the supercritical water gasification system, and supplying the suspension to each device in the supercritical water gasification system A method for operating a supercritical water gasification system, wherein water in which activated carbon is suspended is supplied in advance.   The water in which the activated carbon is suspended is supplied to the supercritical water gasification system by the gas-liquid separator in which the activated carbon having the same concentration as the water in which the activated carbon is suspended is suspended. The operation method of the supercritical water gasification system according to claim 1, wherein the operation is performed until the liquid component is separated and discharged.

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