Pretreatment method of anaerobic digestion treatment of kitchen garbage

Abstract

The invention relates to a pretreatment method of an anaerobic digestion treatment of kitchen garbage. The pretreatment method comprises the following steps: removing bulks, pouring kitchen garbage into a hopper, coarsely grinding and extruding the kitchen garbage, delivering kitchen garbage to a sorting machine, delivering the leachate to a water pot through a leachate collecting tank; sorting out inorganic impurities, punching, grinding, and pulping kitchen garbage, stirring under heating, carrying out solid-liquid separation, delivering solid dregs to an organic substance recovering tank, removing impurities from organic slurry by a first whirl sand removing machine, then extracting oil from organic slurry by a three phase centrifuge; purifying the oil phase by an oil extracting machine, delivering the residual organic slurry to a solid-liquid mixing box; mixing the solid dregs in the organic substance recovering tank and effluent from an anaerobic fermentation system to form slurry, washing the slurry by water, carrying out solid-liquid separation, removing impurities from the separated liquid by a second whirl sand removing machine, and then delivering the liquid to the solid-liquid mixing box. The pretreatment method has the advantages that various greases in kitchen garbage are maximally extracted, inorganic solid impurities are prevented from entering the anaerobic fermentation system, and thus the operation of following treatments becomes stable.

Description

technical field [0001] The invention relates to a pretreatment method for anaerobic digestion of kitchen waste, belonging to the technical field of kitchen waste treatment. Background technique [0002] Kitchen waste, also known as "swill", is a kind of waste produced by people in daily life. It has the characteristics of wide source, large amount of production, and organic matter content as high as 90%. It is suitable for anaerobic fermentation to produce high additional raw material for clean energy. However, affected by various factors in the storage, collection and transportation of food waste, food waste will be mixed with various domestic waste, such as metal, ceramics, glass, etc. In addition, seafood shells and shellfish in the food waste itself , bones, large pieces of meat and up to 2% oil content, all interfere with anaerobic fermentation, and even destabilize the anaerobic digestion system. Therefore, it is very necessary to pretreat food waste and remove vario...

AI Technical Summary

Problems solved by technology

Although this patent can remove coarser objects and grease, and at the same time remove finer metal, glass, bones, etc., but this patent separates coarse and fine impurities through grids of different sizes, so it is easy to cause grid Blockage, and light and fine materials such as fiber strips and fine sand that are difficult to degrade cannot be separated into slurry, which will easily cause surface scum crusting and bottom sediment in the anaerobic digestion treatment system

[0004] CN102888429A discloses "A Pretreatment Process for Anaerobic Fermentation of Food Waste". On the basis of the process of preliminary solid-liquid separation and sorting out organic waste, a desanding process section is added to prevent sand and gravel from clogging the anaerobic fermentation equipment. There is sediment at the bottom of the pipeline and anaerobic equipment, but the oil and water entering the bio-oil separation system have not been treated for sand removal, which will interfere with the normal operation of the bio-oil separation system, and this process cannot remove light and fine materials that are difficult to degrade, such as fiber strips , the anaerobic digestion treatment system is prone to surface scum and crusting

Although this process uses high-pressure cooking methods to extract oils that exist in the form of solid-phase internal oils, but only uses a three-phase centrifuge to purify the oils, the quality of the produced oils is average, and it is difficult to use them directly as chemical raw materials. The oil and water of the three-phase centrifuge are not treated for sand removal, which can easily block the pipeline of the three-phase centrifuge and damage its internal components.

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