Two-phase anaerobic fermentation method for kitchen waste

Abstract

The invention relates to the kitchen waste treatment field, in particular to a two-phase anaerobic fermentation method for kitchen waste. The two-phase anaerobic fermentation method for kitchen waste includes the steps of: 1) sending leached oil water into a grease separation system to undergo grease separation, recovering the separated grease, and carrying the separated wastewater and the kitchen waste conveyed by a lifting screw conveyor to a crushing separation system; 2) carrying out crushing and separation; 3) conducting hydrolytic acidification; 4) inputting the waste slurry subjected to hydrolytic acidification in a hydrolysis tank into a heat exchanger, performing heating, then sending the waste slurry into a fermentation tank to undergo anaerobic fermentation; 5) conducting re-fermentation, and subjecting biogas to desulfurization treatment; and 6) recovering biogas residue and biogas. The method provided by the invention applies the two-phase anaerobic technology to the kitchen waste industry, and can effectively avoid the easy acidification phenomenon of high concentration organic waste anaerobic fermentation. The multifunctional tank integrating gas production, gas storage and desulfurization is adopted in the invention, and the gas production efficiency is improved.

Description

technical field [0001] The invention relates to the field of kitchen waste treatment, in particular to a two-phase anaerobic fermentation method for kitchen waste. Background technique [0002] Food waste refers to food waste and food residues in families, schools, public canteens of government agencies and the catering industry. It is the main component of municipal solid waste. It has the characteristics of high content and rich nutrient elements, and has great recycling value. [0003] Previously, food waste was mainly used as feed for pigs in the suburbs of cities. Due to its complicated sources, it is very likely to cause disease transmission, and it has been banned by the government for feeding. In daily life, residents usually mix kitchen waste with domestic waste and send it to garbage collection points through plastic bags, which changes the composition and characteristics of urban domestic waste. During the storage, collection, transfer and landfill process of fo...

AI Technical Summary

Problems solved by technology

During the storage, collection, transfer and landfill process of food waste, due to its high water content and organic matter content, it is easy to rot, smell and breed mosquitoes in a short period of time, which greatly pollutes the surrounding environment.

In addition, the disposal methods of municipal waste usually include incineration and landfill. If municipal solid waste is incinerated, since the moisture content of kitchen waste is often as high as about 90%, the calorific value is 2100-3100kJ / kg, and it is incinerated together with other waste , not only cannot meet the calorific value requirements of waste incineration power generation (that is, more than 5000kJ / kg), but will cause the incinerator to burn insufficiently and produce dioxins; High content should not be handled

Moreover, incineration and landfill will lead to a large amount of waste of organic matter, so it is necessary to treat food waste separately

[0004] One of the main treatment technologies of existing food waste is to produce combustible gas by anaerobic microbial fermentation of food waste, but anaerobic fermentation has high requirements for fermentation substrates, and food waste contains a large amount of non-organic waste. Treatment and removal will have adverse effects on anaerobic fermentation and greatly reduce the efficiency of anaerobic fermentation

Patent CN101632996A provides a pretreatment process for kitchen waste, which can conduct preliminary solid-liquid separation of garbage and sort out organic waste. However, this process does not separate a large number of sand and gravel particles contained in kitchen waste, and Sand and gravel can block the pipeline of anaerobic fermentation equipment, which is very harmful to anaerobic fermentation

Most of the existing anaerobic fermentation methods for food waste are single-phase anaerobic fermentation methods, that is, the garbage materials are not subjected to hydrolysis and acidification treatment, and anaerobic fermentation treatment is directly performed. This single-phase anaerobic fermentation method can easily make the fermentation process in the fermentation tank Acidification occurs in the medium, which leads to the inhibition of the entire anaerobic fermentation process, greatly affecting the stability of anaerobic fermentation

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