Modified molding and gasifying method for household garbage

Abstract

The invention discloses a modified molding and gasifying method for household garbage. The method comprises steps as follows: the household garbage is subjected to bag breaking, magnetic separation, screening, coarse crushing, medium crushing and fine crushing, and the difference from the prior art is that procedures are added as follows: refined crushing and stirring are performed after fine crushing and an additive 1 is added; primary modification and drying are performed; refined crushing and stirring are performed, and an additive 2 is added; secondary modification and drying are performed; RDF (refuse derived fuel) is prepared, ternary drying is performed; gasification is performed; a product is cooled; tar is removed; chlorine and sulfur are removed, wherein CaO is added and reacts with water in the initial stage of treatment, and reaction heat is released. The reaction of added caustic soda and cellulose is also an exothermic reaction. After addition of sodium chloroacetate, a viscose glue-like mixture is produced through the reaction, and RDF is better in molding effect, is higher in strength and is not prone to dispersing at the high temperature; during modified molding and gasifying of the household garbage, no sewage and waste gas are discharged to the outside; combustible gas is produced after gasification of the household garbage, and the purposes of recycling resources and completely treating the household garbage are achieved.

Description

technical field [0001] The invention relates to the treatment of domestic garbage, in particular to a process method for preparing domestic garbage into derivative fuel (RDF) through modification treatment, and then gasifying the RDF. Background technique [0002] Domestic waste disposal has always been a difficult problem for countries all over the world. Currently commonly used methods include: sanitary landfill, incineration for power generation (or direct incineration), sorting and recycling, biogas production for power generation, etc. But the disadvantages of these methods are very obvious. [0003] 1. The disadvantage of the sanitary landfill method is firstly that it occupies a large amount of land resources, and secondly that the seepage produced after landfill is harmful to the environment and the cost of disposal is very high. [0004] 2. The incineration power generation method must add a large amount of auxiliary fuels such as coal and heavy oil. The biggest ...

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Problems solved by technology

[0003] 1. The disadvantage of the sanitary landfill method is firstly that it occupies a large amount of land resources, and secondly that the seepage produced after landfill is harmful to the environment and the cost of disposal is very high

[0004] 2. Incineration power generation method must add a large amount of auxiliary fuel such as coal, heavy oil, etc.

The biggest problem faced by this method is: the exhausted flue gas needs to go through a complicated treatment process to meet the emission standards; the cost of combustion-supporting materials and flue gas treatment is extremely high, and it is difficult for the local government to pay such a high cost

This is an important reason that restricts the popularization of this method.

[0005] 3. Due to the extensive and vague classification standards, the public cannot accurately judge the simple standard of "recyclable" and "non-recyclable". In addition, the habit of the people and the current situation of domestic garbage collection make this method basically unfeasible sex

[0006] 4. The biogas power generation method cannot be popularized, mainly because this treatment method will cause a large amount of waste residue and waste liquid residue

Due to the high density and heavy weight of derivative fuel (RDF), it is difficult to realize fluidized gasification

If the fuel is pulverized and then gasified, the light substances in the fuel such as plastics are easily sucked out with the mixed gas, causing pipeline blockage, increasing the difficulty of purifying the mixed gas, and causing garbage to be discharged outside. Incomplete

[0011] 3. The compactness of the derived fuel (RDF) is not enough, it is easy to scatter and fragment, resulting in insufficient gaps between fuels

As a result, it is difficult to supply oxygen during gasification, and it is also difficult to discharge the mixed gas after the gas, so the gasification is not sufficient and the efficiency is low

[0012] 4. Dioxins and NO are produced during the gasification process X , SO X Harmful gases such as gasification make it more difficult to purify the mixed gasification produced after gasification, and the purification cost increases

Simply relying on the heat generated in the gasification process to dry the garbage, the heat is not enough, and it will not work

(2) When drying garbage, if the temperature is too high, the phenomenon of external coke and internal humidity often occurs; when the temperature is low, heat is difficult to transfer to the interior of the garbage, and the drying efficiency is very low

[0014] To sum up, the problems that are currently difficult to promote and popularize such methods are:

Only considering the use of heat energy in the gasification process, without making preparations for gasification efficiency and flue gas treatment, resulting in slow gasification process and high purification cost of the generated mixed gas

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