Comparison Between Anaerobic Digestion and Black Soldier Fly Food Waste Treatment

At present, the mainstream treatment technologies of food waste are anaerobic digestion and the emerging technology of black water fly breeding. The two treatment methods are compared and analyzed from the aspects of harmlessness, reduction, recycling degree, feeding requirements, technical reliability, project scale, site selection, floor area, investment, treatment cost, applicable conditions and management level, as shown in the following table:

Compare items	Anaerobic Digestion Treatment	Black Soldier Fly Treatment
1. Harmless Degree	High	High
2. Quantifiable Degree	Lower.The inorganic substances screened out need to be landfilled or incinerated. Besides a small amount of organic matter converted into biogas, a large amount of biogas residue and sewage need to be treated.	High. Except for some selected inorganic substances (about 20%) which need to be landfilled or incinerated, other substances are sold as products without subsequent landfill or incineration treatment.
3. Degree of resource utilization	Relatively high	Relatively high
4. Technical reliability	Relatively reliable. It has been put into practice in all parts of China, and there are many cases of stable operation projects, which is the mainstream process of food waste treatment in China at present.	Medium, there are individual small application cases at present, and there are few engineering cases of stable operation
5. Material requirements	It requires high quality of raw materials and needs pretreatment.	It requires high quality of raw materials and needs pretreatment.
6. Examples of project scale	There are examples of large-scale projects in China, and the daily treatment capacity has reached 1000 tons. The process is relatively mature at present.	In China, there are only small-scale projects with a daily treatment capacity of less than 100 tons, and the process is currently in the experimental stage.
7. Site selection is difficult or easy	Medium, it is only necessary to avoid densely populated areas, the odor influence radius is less than 300 m, and the transportation distance is moderate.	Medium, it is necessary to avoid densely populated areas, the radius of odor influence is less than 200 m, and the transportation distance is moderate.
8. Floor space	Medium, generally 110 ~ 150 ㎡/t	Medium, generally 110-130 ㎡/t
9. Project investment/ (rmb/t)	400,000~650,000 rmb/t	300,000~500,000 rmb/t
10. Energy consumption/ (200 UI)	The energy consumption is large, the high-power mixing equipment and protection equipment consume electricity for days, and the energy consumption for treating 1 t of garbage is about 40 kw.	The energy consumption is large, and the high-power mechanical equipment is mainly used for temperature and humidity control.Installed capacity of 1200 kW
11. Final product	Biogas power generation, biodiesel	Insect protein, biological fertilizer
12. Final disposal	Inorganic matter and biogas residue need to be landfilled or incinerated, accounting for about 40% -50% of the feed, and 70% -100% of the biogas slurry needs further treatment after anaerobic fermentation.	Inorganic materials need to be landfilled or incinerated, and the final treatment capacity is closely related to the purity of incoming materials, generally about 20% of the initial amount.
13. Air Pollution	Slight odor, requiring deodorization device and isolation belt	Slight odor, requiring deodorization device and isolation belt
14. Water pollution	It is more likely that a large amount of biogas slurry needs to be treated after the treatment of this process, and if it is not properly treated, it will produce certain water pollution.	The possibility is small, and the process generates little sewage.
15. Main risk	(a) Garbage composition analysis is required before production; (b) There are potential safety hazards in the collection and utilization of biogas; (e) There are many waste water and waste residues produced, and corresponding equipment is required in the follow-up.	(a) The purity and freshness of incoming materials will seriously affect the quality of food waste treatment; (b) Whether insects will be infected with bacteria and other unstable factors in the process of insect breeding is also a risk point; (e) The stability of market sales; (d) There are few cases in China, and there are certain risks in technical stability.