JP2006247437A - Thermal decomposition, carbonization and gasification treatment method for organic waste with no use of fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal decomposition method for an organic waste in which an energy of a heavy oil or the like is not used and a harmful compound such as dioxin is not by-produced, and an apparatus. <P>SOLUTION: In the organic waste treatment method, oxygen is diffused to the whole of a bottom surface of a thermal decomposition reactor 1 and a part of the organic waste product having calorific power and moisture content adjusted to the optimum is partially oxidized. Since an amount of oxygen is controlled by a valve at a distal end of an introduction pipe, the inside of the thermal decomposition reactor 1 in the non-oxygen state and by-production of the harmful compound such as dioxin is not totally generated. The partially oxidized organic waste product becomes ash and heat is generated. The peripheral organic waste product is thermally decomposed, carbonized, gasified and incinerated by the heat. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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Without using fuel, a part of organic waste is partially oxidized and the organic waste is pyrolyzed, carbonized, gasified, and incinerated without generating harmful compounds such as dioxin by the heat. The present invention relates to a small distributed method and apparatus for processing.

Detailed Description of the Invention

The present invention does not use fuel and does not produce harmful compounds such as dioxins, by pyrolysis of organic waste, and the resulting carbide and ash are made into very effective fertilizers and soil conditioners. The present invention relates to a small and distributed resource recycling method and apparatus that does not generate any waste.

Organic waste is generally landfilled or incinerated. However, when organic waste containing chlorine compounds is combusted, dioxins are by-produced and must be burned at a high temperature using a large amount of heavy oil. Japan is obliged to reduce greenhouse gases by 6% based on 1990 in the Kyoto Protocol until 2012, and the current system that uses a large amount of heavy oil for the treatment of organic waste with low productivity is very There is a problem.

Problems to be solved by the invention

The present invention overcomes the disadvantages of the prior art and uses part of the internal energy of organic waste without using energy such as heavy oil, so that organic waste can be disposed without by-producting harmful compounds such as dioxin. The purpose is to develop a resource recycling method and equipment that pyrolyzes the product, turns the generated carbide and ash into a highly effective fertilizer and soil conditioner, and does not emit any waste.

Means for solving the problem

The requirements of the invention for solving the above-mentioned problems are as follows.
(A) a pyrolysis reactor having an introduction pipe for introducing oxygen to the bottom while controlling oxygen; and (b) the length of the introduction pipe inside the pyrolysis reactor is partly in the center, part in the middle, The part is made so that oxygen diffuses at the end, and (c) the ash obtained by thermal decomposition is laid down so that the introduction pipe is buried, the oxygen diffusion rate is controlled, and the generated hydrochloric acid is neutralized Used as a catalyst for gasification reaction, trapping agent for water and high-boiling organic matter produced, and (d) filling organic pyrolysis reactors prepared by calculating calorific value and water content without any gaps And heat exchange with moisture and organic matter generated by pyrolysis and returning it to the reaction system again; and (e) a pyrolysis method of organic waste having a cooler with a structure that prevents backflow of oxygen and an outlet. As well as a device.

The mechanism for generating dioxin is a reaction between hydrochloric acid (HCl), oxygen (O ₂ ) and a precursor generated by decomposition of organic waste containing chlorine. Therefore, if oxygen is suppressed as much as possible, the production of dioxins can be prevented. This is why the amount of dioxins produced in carbonization furnaces such as charcoal pots is very low. As a result of various investigations and examinations, if a small amount of oxygen is sent into a sealed pyrolysis reactor and only a small portion of organic waste is partially oxidized, heat is not supplied from the outside. The present invention was completed by finding out that the whole can be distilled, carbonized, gasified and incinerated without any raw material.

Next, the detailed contents of the present invention will be described. Fill the bottom of the sealed pyrolysis reactor with ash so that the introduction pipe is buried, and fill the organic waste with adjusted calorific value and moisture without gaps, and the boundary between the central ash and organic waste Heat with an electric heater. Turn off the electric heater as soon as the temperature rises and some of the organic waste is ignited. Oxygen in the pyrolysis reactor is immediately consumed and becomes oxygen-free, and oxygen that has diffused through the introduction pipe and ash partially oxidizes only organic waste at the boundary with ash and becomes ash itself. Fever. Since this heat is covered with organic waste that does not conduct heat well, heat is stored, and the surrounding organic waste is thermally decomposed to generate gas, pitch, carbide, and the like. For this reason, the interface with ash is always a substance that is easily oxidized, such as cracked gas, pitch, and carbide. Oxygen transported by concentration diffusion through the inlet pipe and ash is consumed by partial oxidation of gas, pitch, carbide, etc. at the interface with ash, so organic waste above the layer where partial oxidation occurs Since thermal decomposition of the product is performed in an anoxic state, almost no byproduct of harmful compounds such as dioxin occurs. The thickness of the partially oxidized layer is so thin that the temperature cannot be measured and can only be judged in the ash state. However, heat is likely to accumulate, and high-calorie carbides, gases, pitches, etc. are oxidized, resulting in high temperatures of 800 ° C or higher. It is estimated that Gas generated by pyrolysis and evaporated water rise while exchanging heat in the organic waste that is packed, but almost all of the high boiling point pitch and dioxin precursors are in the organic waste. It is collected and does not come out. These eventually reach the interface of the ash layer and become ash by partial oxidation. There is no problem with the water content of organic waste up to about 60%, but the role of water is considered as follows. Moisture with large latent heat and low boiling point becomes vapor in the partial oxidation layer and rises in the organic waste, and the temperature of the entire organic waste is raised by heat exchange. In addition, hydrochloric acid, which is a causative substance of dioxin generation, is dissolved by heat exchange and dissolved in hydrochloric acid, enters the ash layer through the wall, and reacts and fixes ash containing a basic substance and hydrochloric acid. Moisture entering the ash reaches the partially oxidized layer by capillary action, and promotes gasification of the partially oxidized layer together with water droplets falling from the organic waste. At that time, ash is considered to act as a gasification catalyst when estimated from its components.

The present invention is clearly different from the incinerator. In combustion, air more than 10 times the fuel is forcibly blown, and because the exhaust gas flow rate is large, a large amount of dust attached with high boiling point dioxin and fly ash attached with dioxin recombined in the exhaust gas cooling process Therefore, it is necessary to install very expensive dust collectors and filters. However, in the apparatus of the present invention, in order to supply oxygen into the pyrolysis reactor by oxygen concentration diffusion, supply a small flow rate that does not move even if a thin paper or cigarette smoke is put over the tip of the introduction pipe. Not. When pyrolysis begins, the pressure in the pyrolysis reactor increases, and almost no air flows from the inlet pipe with the valve only slightly open. However, oxygen in the pyrolysis reactor is consumed immediately by partial oxidation, so the oxygen concentration is close to zero. Therefore, it is considered that oxygen flows from outside air having a high oxygen partial pressure by concentration diffusion.
The amount of exhaust gas is very small, and dust is not generated at all because it goes to the discharge port while exchanging heat in thick organic waste. Therefore, even if dioxin is generated, it is collected in the organic waste, and eventually reaches the partially oxidized layer and decomposes.

The process of the thermal decomposition reaction of organic waste is schematically shown in FIG. Oxygen diffused through the ash generates heat by oxidizing carbides, pitch, and gas generated at the interface with the ash. This layer is heated to a high temperature of 800 ° C. or higher because of high-calorie substances. Moisture rising from the ash and water droplets falling from the top become high-temperature water vapor, which promotes gasification and carbonization of organic waste. There is a slightly thick carbonized layer thermally decomposed in the absence of oxygen on the high temperature layer. This layer eventually comes into contact with the ash and becomes a high temperature layer. Above that there is a layer of organic waste that has not undergone thermal changes. This layer heat-exchanges with water vapor and the temperature rises, but it is about 50 ° C. to 70 ° C., so it is wetted by water droplets and seals the gas and organic vapor below. In this way, since most organic wastes undergo thermal decomposition in the absence of oxygen, harmful substances such as dioxins are not secondary. The precursor that causes the generation of dioxins is cooled to the extent that it is warm enough to touch the side wall and upper part of the pyrolysis reactor, and returns to the pyrolysis reactor and hardly goes outside.

Inside the pyrolysis reactor is an internal wall with a number of holes to insulate and remove excess moisture. The shape of the hole may be any shape as long as it allows gas to pass and the condensate to flow into the ash layer. For example, the hole is punched so that the top opens from the outside to the inside. Then, when the vapor or organic gas generated from the inside of the pyrolysis reactor enters between the outer wall and the inner wall and is cooled by the outer wall and flows down as a condensate, it does not return to the inside of the pyrolysis reactor. It can flow to the ash layer.

Embodiments of the Invention

Embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 2 shows a front view of the pyrolysis reactor. This is an example of the manufactured pyrolysis reactor, and is not limited thereto. The pyrolysis reactor 1 is made of iron and has a cylindrical shape with a diameter of 1000 and a height of 1200. FIG. 3 shows a sectional view of the pyrolysis reactor as seen from above. Four 400 introduction pipes, 4 200 introduction pipes, and 8 100 introduction pipes are attached to the bottom of the pyrolysis reactor from the inner wall toward the center. Each inlet pipe is provided with a valve for controlling the oxygen diffusion rate. If the oxygen supply is too high, close some valves. The bottom of the pyrolysis reactor is sloped so that the ash can be easily taken out, and a rotary valve or the like is attached to the tip of the pyrolysis reactor so that the feet can be adjusted to a height that makes it easy to take out the ash. An opening is provided in the bottom side wall of the pyrolysis reactor to take out metal that has been inspected or misplaced. This door is usually completely sealed by heat-resistant packing. An inner wall with a large number of holes is provided inside the pyrolysis reactor with an appropriate gap. Excess water and organic vapor pass through this hole, come into contact with the outer wall, cool down, flow down, adhere to organic waste, and are thermally decomposed, so that only a little is discharged to the outside. Moisture penetrates into the ash layer and partly rises by capillary action and is used for gasification reaction of organic waste. Exhaust gas is discharged by bubbling condenser cooling water, and is also cut off from outside air.

The invention's effect

Part of organic waste that comes into contact with the ash layer is partially oxidized, and the exothermic heat causes pyrolysis, carbonization, and gasification of most other organic waste in the absence of oxygen. This is a method of treating organic waste without fuel without the by-product of harmful compounds.

Place 5 bags of garbage in a 45L plastic bag, 200kg of paper such as phonebooks, magazines and newspapers, polystyrene for packing, etc. into a pyrolysis reactor, fill the gap and the top with 100L of rice husk, and fill the inlet Closed. The total capacity is about 1000 L (weight 250 kg). The heater was heated with an ignition heater, and the heater was turned off as soon as smoke began to come out of the chimney. The valve was opened a little at the beginning, and slightly opened after the thermal decomposition started smoothly. The outer wall temperature of the pyrolysis reactor was initially room temperature but gradually warmed, and the temperature of the entire outer wall became a steady state of about 50 ° C to 60 ° C. As it was, it was left unattended for 24 hours for thermal decomposition. As a result of opening the inlet and inspecting the inside, the organic waste was a black carbide with 1 cm on the surface, but the bottom was all whitish ash. The dry distillation liquid was about 10L. The gas, dry distillation liquid, and ash discharged from the discharge port were collected and analyzed for dioxins and coplanar PCBs. The result was 0.2 pg-TEQ / Nm ³ of exhaust gas in terms of toxic equivalent, 0.009 ng-TEQ / in dry distillation liquid. g, Ash was 0.008 ng-TEQ / g, and the environmental standard value of the exhaust gas country was 5.0 ng-TEQ / Nm ³ , and the treated ash environmental standard value was 3.0 ng-TEQ / m ³ . .

Claims (5)

Oxygen is controlled and introduced into the pyrolysis reactor, and the amount of heat generated and moisture are adjusted optimally to partially oxidize part of the organic waste filled in the pyrolysis reactor to heat the heat. Stores heat in the decomposition reaction vessel, pyrolyzes, carbonizes, gasifies, and incinerates most other organic waste without generating by-products such as dioxins and without supplying energy from the outside A method of treating organic waste. A plurality of openings are provided at the bottom of the pyrolysis reactor, an introduction pipe for introducing oxygen into the pyrolysis reactor is attached, and a valve for controlling the amount of oxygen is attached to the tip. The length of the introduction pipe inside the pyrolysis reactor is adjusted so that oxygen diffuses partially in the center, partially in the middle, and partially in the end. The method described. 2. The method according to claim 1, wherein the ash produced by the pyrolysis reaction is spread to such an extent that the introduction pipe is filled, the oxygen diffusion rate is controlled, and the gasification of organic waste is promoted by the catalytic action of ash. . 2. The method according to claim 1, wherein an excess of water and organic vapor are removed by providing an inner wall with a large number of holes inside the pyrolysis reactor. 2. A method according to claim 1, wherein a magnet of 2000 gauss or more is attached to the tip of the valve.