JPS61293297A - Method of reforming combustible gas - Google Patents

Abstract

PURPOSE:To obtain a high-quality gas with high efficiency, by feeding a high- temp. combustible gas produced in a waste treating a high-temp. combustible gas produced in a waste treating apparatus into the bottom of a vertical combustible gas reforming apparatus packed with a granular coke at the upper part of the bed equipped with a heat source. CONSTITUTION:A waste is stored on a roaster 30 provided within a vertical waste treating apparatus. Air is fed via primary and secondary gasifying air inlets 10, 5 while a fuel 9 is burnt with a burner 4 for gasification. The generated high-temp. combustible gas is fed to the bottom of a vertical combustible gas-refoming apparatus 15 via an outlet 6 and a duct 8. Carbon, tar, etc. contained in the gas are oxidized with the air fed through a nozzle 18 of an air pipe 16, and the gas is brought into contact with a granular coke 14 placed on a bed 13 preheated with a heater 12 to allow it to reduce, fed to a gas cooling tower 19 via an outlet 17 to allow it to rapidly cool, fed into a scrubbing tower 20, where it is scrubbed with an alkali to absorb and remove hydrogen chloride, SO2 gas, etc., and taken out of the system via an outlet pipe 21.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for reforming combustible gas, and more particularly, to a method for reforming combustible gas, which improves the quality of combustible gas generated from waste treatment equipment. Regarding modification methods.

<Conventional Technology> In modern society, the amount of various municipal wastes and industrial wastes has increased dramatically, and the treatment of these wastes has become a serious problem. These municipal wastes and industrial wastes include household garbage,
There are a wide variety of materials such as plastics, waste tires generated from industrial systems, waste plastics, waste paper, waste wood, etc., and because they have value as an excellent heat source with a relatively high calorific value, it is not enough to simply incinerate them. The social loss is large.

Therefore, various attempts have been made to utilize these as fuel and heat sources. However, if these are used directly as fuel, for example as a heat source for industrial equipment such as Zeira,
This causes a number of negative effects such as the generation of black smoke and harmful gases. Furthermore, if each of these is treated individually, various dedicated treatment facilities will be required, making the treatment extremely complicated and difficult. For example, if plastics or waste tires are directly burned, they will reach high temperatures that will corrode equipment, produce black smoke, and contain highly toxic gases in the exhaust gas. Unfavorable from the standpoint of pollution control and environmental conservation. Furthermore, when these wastes are collected and delivered, various kinds of wastes are mixed together, and the work of separating and sorting them is extremely complicated, and it is extremely difficult to completely burn these mixed wastes. Conventional combustion methods cause problems such as the generation of bad odors due to incomplete combustion, the generation of large amounts of exhaust gas, and the generation of unburned ash.

To this end, the above-mentioned wastes are thermally decomposed and gasified in waste treatment equipment, and the flammable gas is used as fuel.

<Problems to be solved by the invention> As mentioned above, the flammable gas generated from the waste treatment equipment is sent through piping to a combustion device such as a furnace and burned in a nozzle. Inside is usually lO~30
? /Nm” of tar and free carbon, which can clog pipes and burner nozzles.For this reason,
Insulating, managing, and maintaining remote piping and combustion equipment required a great deal of effort and caused various troubles.

The present invention solves the above-mentioned problems by secondarily re-pyrolyzing the tar and free carbon in the combustible gas generated through the process of thermal decomposition and gasification of waste. The purpose is to make the carbon dioxide and water vapor in the gas react with coke, etc., to improve the calorific value and quality of the entire gas, and to enable stable combustion using a gas nozzle. The present invention aims to provide a method for reforming combustible gas that purifies the combustible gas so that it can be effectively and appropriately used as a heating heat source for various types of rice.

Means for Solving Problems〉 The combustible gas reforming method of the present invention is a vertical combustible gas reforming method that has a bed inside, is equipped with a heat source, and is filled with granular coke above the bed. The next combustible gas generated in the waste treatment equipment is introduced from the bottom of the equipment in a high-temperature state without being cooled and rises as an upward flow.
The coke is heated red-hot by the heat source, and air is supplied from a companion nozzle located below the bed.

<Example> Hereinafter, the structure of the method of the present invention will be explained in more detail with reference to the example shown in the drawings.

FIG. 1 is a system explanatory diagram of one embodiment of the apparatus used in the method of the present invention. The combustible gas is sent to the combustible gas reformer B and passed therethrough for reforming treatment.

The waste treatment equipment consists of a vertical tank that can carry out the waste storage process and the gasification reaction process 2 completely continuously. Waste is stored on 3o. The Rossdol 30H is equipped with a drive device (not shown) and performs movements such as rocking, sliding, and rolling at any time to assist in the gasification of waste, and then gasifies and thermally decomposes the waste through the air intake port 10 for gasification. Gasification continues by feeding the appropriate amount of air required.

Further, a necessary amount of air for secondary gasification is mixed in from the air intake port 5 for secondary gasification to further promote gasification.

In this reverse smoke combustion, the above-mentioned under-burning type gasification step 2, the waste is rapidly Vr-oxidized and decomposed by the air from the air intake ports 10 and 5, reaching the gasification temperature and completing the gasification. Gasification in this case is a producer gas reaction that generates combustible gases, a water gas reaction, and the production of pyrolysis products. The generated combustible gas is sent out from the combustible gas outlet 6 to the combustible gas reformer B in a high temperature state.

For ignition and preheating at the start of this waste treatment apparatus, an ignition fuel (mainly city gas, kerosene, etc.) 9 is combusted using an ignition combustion nozzle 4. Gasification residue ilt
It is taken out from the waste residue removal lower.

The gas generated in the waste treatment equipment A is usually called a dirty gas because it contains carbon dioxide, carbon dioxide, water vapor, etc. due to the non-uniform combustion rate due to the non-uniformity of the waste and the irregular shape of the waste. The calorific value varies, the flame propagation speed also varies, and when using this as a fuel, there are various restrictions on usage conditions.

The high temperature combustible dirty gas generated from the gasification step 2 is fed into the combustible gas reformer B through the combustible gas duct 8. This flammable gas reforming system [Purpose of B (2) mainly involves the gasification of tar, carbon dioxide, and combustible gasification through the reduction reaction of carbon dioxide and water vapor, and the reduction of harmful substances such as hydrogen sulfide, ammonia, and hydrogen chloride. , oxidation is also taken into account.

The combustible gas introduced from the flammable gas λ port 11 provided at the bottom of the flammable gas reforming system #B consisting of the vertical tank-shaped gas reforming tower 15 is taken out from the gas reforming air pipe 16. The oxidation of carzene and tars is promoted by a very small amount of air as an oxidizing agent. A heat source heater 12 is provided above the air pipe 16, a ped I3 is provided above the ped I3, and a bed 13 is filled with granular coke. The heat source heater 12 preheats the combustible gas reformer B at a temperature of 600 to 700°C or higher at the start, and also heats the coke packed bed 14 on the bed 13.
Preheat and heat so that the reduction reaction can occur quickly.

The reformed combustible gas outlet 17 at the top of the gas reforming tower 15 converts it into Izumo combustible gas, which is rapidly cooled to room temperature in the gas cooling tower 19 and subjected to alkali cleaning etc. in the gas cleaning tower 20 to absorb hydrogen chloride and sulfur dioxide gas. Once removed, the reformed clean gas is taken out from the thread through the outlet pipe 21.

The reformed clean gas extracted in this way can be burned in a normal gas burner or the like and can be used extremely effectively as a heat source.

In the heating oxidation step 38 in the gas reforming step, air within the range of 5 to 10% of the amount of combustion air required by the combustible gas sent from the combustible gas duct 8 is used as the gas reforming air. It is fed continuously or intermittently through tube 16. In addition, part of the combustible gas is burned, and an exothermic reaction keeps the temperature of the bed and coke layer at a high temperature. progresses.

Figure 2 (A) shows a cross section of the H combustible gas reformer.The heat source heater 12 is connected to the power supply terminal 23, and when the electric power is fully loaded from the outside, the heat generated by the resistance heating element causes coke. A 13ft bed was heated and kept warm to stabilize the above reaction.

The combustible gas heated in this way and reaching 800 to 900°C is introduced into the next endothermic reduction step 39Vc, and is transferred to the bed 13.
The reaction of 0+OCh → 200 0+H20 → OO+ I (2) and the catalytic effect of the ped 13 thermally decomposes the tar content and generates CH4 and Hz. Due to the endothermic reduction reaction, the temperature drops to the inside temperature of the vessel, and the outlet temperature becomes 600° C. or less, and the above reaction is terminated.

As described above, in the lower stage of the combustible gas reformer BH1, tar and casene are oxidized and thermally decomposed using an oxidative exothermic reaction, and in the upper stage, the coke and bed are all kept under high temperature conditions to perform an endothermic reduction reaction of the gas. This is to improve the quality of the gas. Tar, carzene, and heavy hydrocarbons in the gas are thermally decomposed and converted into a combustible gas such as Hz + OH4100 that can be stably combusted, and the gas calorific value can be made uniform.

That is, the method of the present invention combines waste treatment equipment A and combustible gas reformer B to dispose of various polymer plastics at relatively low temperatures of 600 to 900°C and under conditions with little clinker trouble or high-temperature corrosion. It processes waste materials, waste tires, wood chips, waste wood, etc., and enables the effective use of waste resources as heat, making it ideal for both mixed processing and single processing. Moreover, the equipment used in this method has fewer mechanical parts that can cause thermal troubles and corrosion, and can be operated safely and reliably.The waste treatment equipment uses high-quality combustion, as mentioned above, and the combustion rate can be easily controlled. In the t-It combustible gas reformer, the combustible gas is brought into contact with the coke as the fixed bed, so the thermal efficiency is high and the scavenging time is sufficient. Therefore, it is possible to carry out the oxidation exothermic reaction, endothermic reduction reaction, etc. in each step according to the set conditions.

FIG. 2(B) is a sectional view showing another embodiment of the combustible gas reformer, in which an electric resistance heating element is not used as the heat source heater, and the heating oxidation step 38 is performed using city gas or fuel gas (oil) on kerosene. ) The fuel is introduced through the inlet pipe 28 and combusted in the heating/decomposition nozzle 29, and is operated using externally supplied fuel as the heat source. In the case of this heating method using externally supplied fuel, it is also possible to install two gas reforming units 15 and operate by alternately switching between heating oxidation and endothermic reduction, which is a preferable method in the case of large capacity. . In addition, in FIGS. 2(A) and (B), 22 is a heater support, 24#'i is a coke filling manhole, and 25 is an ash? 26 is an ash outlet, and 27 is a fireproof insulation material.

FIG. 3 is a sectional view illustrating a self-cleaning regeneration method for a combustible gas reformer. When the combustible gas reformer B processes dirty combustible gas generated from the waste treatment equipment for a certain period of time, the bed and coke become contaminated with cardin and tar. At night or before regular inspection stops, after stopping the operation of the waste treatment equipment, operate the control panel 36 to operate the ignition pilot burner 31 in a fully automatic operation mode, and open the ignition air solenoid valve 3. Ignition gas solenoid valve 33,
The heating and decomposition nozzle 29 is ignited using the fuel pipe 34 and the combustion air pipe 35, and the adhered cargin, tar, dust, etc. are burned out. In this case, the temperature within the coke layer is controlled using a thermometer 37 to maintain a constant temperature. Although not shown in this figure, there is a relief valve for exhaust gas during firing, and a relief valve for exhaust gas after firing. The structure is designed to eliminate strikes. The phosphoric acid air is sent using the gas reforming air pipe 16, but in order to improve the firing efficiency, humidification water 40 is also atomized and evaporated into the supplied air to humidify it.

This allows firing to proceed more effectively and quickly. At this time, the coke itself will also be slightly consumed.

<Effects of the Invention> As is clear from the above explanation, the method of the present invention can be applied to wastes, especially wastes and wastes having a high calorific value such as plastics, polymer compounds, waste tires, bim, etc. A device that generates flammable gas by gasifying wood, chips, etc., and reforming the gas by effectively and appropriately combining three functions: the sensible heat of the flammable gas, an auxiliary heat source heater, and partial combustion by mixing air. and I 000 KOa
J/ Nm! This system secondarily gasifies tar and cardin in the generated gas and transforms it into clean gas with fewer troubles. Therefore, by carrying out the method of the present invention, the conventional problems such as blockage of pipes and clogging of nozzles due to tar and cardin are fundamentally solved, and the convenience of users is immense.

[Brief explanation of drawings]

Fig. 1 is a system explanatory diagram of an embodiment of the apparatus used in the method of the present invention, Fig. 2 is a sectional view of a combustible gas reformer used in the method of the present invention, and Fig. 3 is a sectional view of a combustible gas reformer used in the method of the present invention. FIG. 2 is a cross-sectional view illustrating a self-cleaning regeneration method for a quality device. A...Waste treatment equipment, B...Flammable gas reformer, 1
・・Waste storage tank, 2・・Gasification reaction process, 11・
・Flammable gas inlet, 12. Heat source heater, 13. Bed, 14. Coke packed bed, 16. Air pipe for gas reforming, 18. Air nozzle for gas reforming, 29. Heating and decomposition. Nozzle for. Patent applicant: Tonami Electric Engineering Co., Ltd. Agent: Patent attorney: Tadashi Shimura Kazu II Figure

Claims (1)

[Claims] The combustible gas generated in the waste treatment equipment is heated to high temperature without being cooled from the lower part of the vertical combustible gas reformer, which has a bed inside and is equipped with a heat source and is filled with granular coke above the bed. A method for reforming a combustible gas, characterized in that the coke is fed in a state in which it rises as an upward flow, the coke is red-hot by the heat source, and air is supplied from a nozzle arranged below the bed.