Method and equipment for preparing fuel from household garbage for suppressing dioxin

Abstract

The invention relates to a method and equipment for preparing fuel from household garbage for suppressing dioxin. The method comprises the following steps of: introducing a heat source into vertical heat treatment equipment by using high-temperature gas as the heat source to ensure that the heat source is in direct contact with the household garbage in the vertical heat treatment equipment to cause heat transfer; performing thermal cracking reaction after the raw materials are heated; recovering and utilizing the cracked gas phase product; burning out residues caused by thermal cracking; and introducing high-temperature smoke gas generated by burning into the heat treatment equipment to heat the raw materials. The equipment for preparing the fuel from the household garbage for suppressing dioxin provided by the invention mainly comprises the vertical heat treatment equipment for drying the household garbage and performing thermal cracking on the household garbage, equipment for burning the cracked residues and collection and utilization equipment for the gas phase product. The method and the equipment have the advantages that equipment structure is simple, large-scale, continuity, reclamation and minimization treatment of the household garbage can be realized, and the like.

Description

technical field [0001] The present invention relates to a method and equipment for producing fuel from domestic waste that curbs the generation of dioxin; specifically, it belongs to the direct contact heat transfer between domestic waste and high-temperature flue gas, and performs carbonization under anaerobic conditions to obtain fuel (fuel oil or / and Gas) method and apparatus. technical background [0002] With the development of society and the improvement of people's living standards, the content of organic components in domestic garbage and garbage has been increasing, and has seriously harmed the living environment of human beings. Effectively disposing of these wastes to make them harmless and recyclable has become a subject of global attention and research. [0003] The composition of domestic waste is complex, and the existing domestic waste (or including medical waste) heat treatment technology and equipment, such as gasification incineration method, direct incin...

AI Technical Summary

Problems solved by technology

[0003] The composition of domestic waste is complex, and the existing domestic waste (or including medical waste) heat treatment technology and equipment, such as gasification incineration method, direct incineration method, etc., all have the defect that the tail gas contains dioxin; The organic waste is pyrolyzed in the reduction zone and cracking zone at 500-900°C into a low calorific value (5000KJ / Nm 3 left and right) gas (CO, CH 4 、C 2 -C 5 , N 2 、H 2 , CO 2 ); At present, the heat utilization rate of the most advanced gas-fired power generation in the world is at most 33%, and the remaining heat is lost from the high-temperature flue gas discharged from the gas-fired generator, while the direct incineration method uses the organic waste in domestic waste All incinerated to ashes, the high-temperature flue gas produced is used as the heat source of the steam boiler to generate water vapor, while the heat utilization conversion rate of the steam-driven steam turbine generator is only about 22%, and a large amount of energy is lost and cannot be recycled, resulting in garbage The resource utilization rate is low;

[0004] The prior art has disclosed some technical schemes to solve this problem; the inventor disclosed a method for producing hydrocarbons from domestic garbage and / or organic waste in USP6,133,491, USP6,270,630B1 and ZL98117823.5 and equipment, discloses the first-stage and second-stage thermal cracking and catalytic cracking treatment methods for the same raw material using steel reaction equipment at two different temperatures, low and high; however, to make various organic substances in domestic waste Complete decomposition must reach a high temperature environment of 800-1100°C, but a single steel rotary reactor is easily deformed and cannot be rotated in a high temperature environment for a long time, and the cracking reaction cannot be carried out to the end, resulting in a certain amount of organic matter remaining in the residue of the cracking reaction. Macromolecular substances cannot be completely decomposed, and the thorough reduction and harmlessness of domestic waste cannot be implemented; the inventor disclosed a method for continuous treatment of domestic waste in ZL200710130127.5. The garbage is transported to the closed pyrolysis equipment, and the steel equipment is heated indirectly under anaerobic conditions to generate thermal cracking of the raw materials; however, the thermal efficiency of indirect heating is low, the energy consumption is high, the pyrolysis time is long, and the cost of garbage treatment is high. Knownly, a single domestic waste incinerator is usually horizontal or vertical, such as Martin incinerator, fluidized incinerator, reciprocating grate incinerator, various vertical or horizontal incinerators, and fluidized bed incinerators. ...and so on, the furnace body is huge, the heat dissipation area is large, the comprehensive utilization rate of heat is low, and the investment is large, the profit return rate is low, it is not suitable for economically underdeveloped countries and small and medium-sized towns, and the promotion and application value is low; With the transmission of the incineration grate, in the process of moving domestic waste from the drying area (low-medium temperature area) to the combustion area (high-temperature area), it must pass through a temperature range of 500-700 ° C. In this temperature range, the waste contained in the domestic waste Chlorine-containing substances such as salt or chlorine-containing plastics (PVC) and C and H elements and oxygen O in the air 2 Combined into harmful dioxins (PCDFs), it has caused serious pollution and harm to the environment, which is an unavoidable objective fact

In ZL201120082883.7, "A Garbage Dry Distillation Pyrolysis and Gasification Device Effectively Containing Dioxins" is disclosed, and in ZL201110073735.3, "A Comprehensive Waste Treatment and Utilization Method Effectively Containing Dioxins" is disclosed, The dry distillation or decomposition equipment of the above two kinds of domestic wastes all belong to the conventional gasification incinerator. "Gasification-incineration" combined biomass gas production furnace, domestic waste raw materials are added into the furnace from the upper part of the furnace body, and continuously move down until the bottom of the furnace turns into ashes, and domestic waste moves down to the cracking area (500- 700°C) or reduction zone (about 850°C), affected by the eddy current or kick flow of the upwardly flowing air, some chlorine-containing substances such as salt or chlorine-containing plastics contained in domestic garbage will react with oxygen in the air, which will inevitably A considerable amount of dioxins (PCDFs) are produced objectively and objectively; especially, if this kind of gasification incinerator is used as a pyrolysis device for domestic waste, a large amount of recyclable energy contained in domestic waste can produce high-value Commodity organic hydrocarbons (such as plastic or rubber) are burned in the reduction zone and combustion zone at a high temperature of 850-1100 °C, and only a small part is converted into a low calorific value combustible gas containing a large amount of 40-50% (V%) nitrogen , cannot better implement the resource utilization of domestic waste;

Images