Method for producing biogas by anaerobic digestion of waste oil

Abstract

The invention discloses a method for producing biogas by virtue of anaerobic digestion of waste oil / fat. The method comprises the steps of preparing an anaerobic fermentation strain, adding an inorganic medium and carrying out an anaerobic digestion, and comprises the following specific steps: adding anaerobically digested sludge and fat-degradable bacteria to a base culture medium as an anaerobic fermentation strain, wherein the mass ratio of the anaerobically digested sludge, fat-degradable bacteria and base culture medium is (100-300):(1-2):1000; adding an inorganic medium into the anaerobic fermentation strain at a mass ratio of (1-12):100; sequentially adding the anaerobic fermentation strain, waste oil / fat and additives at a mass percentage of 100:(1-2):(0.1-0. 15) into an anaerobic fermentation device, evenly mixing and carrying out an anaerobic fermentation to produce biogas. The activity of fat-degradation in the reaction system is increased by adding microorganisms and acclimating to form an anaerobic bacteria strain, the adhesion and contact area between the microorganism and oil / fat is increased by adding the inorganic medium, and thus the waste oil / fat is converted into biogas.

Description

technical field [0001] The invention relates to the technical field of waste oil treatment, in particular to a method for using anaerobic fermentation technology to anaerobically ferment waste oil to produce biogas. Background technique [0002] The waste water produced by the catering industry, slaughterhouses, meat / dairy processing plants, etc. is rich in easily biodegradable organic matter and non-biodegradable oils. Among them, the kitchen waste is rich in various animal and vegetable oils, and the oil content generally accounts for about 10% of the meal. 8-10% of the total kitchen waste. Driven by profit, some unscrupulous traders illegally sell "gutter oil" made from waste kitchen grease, causing it to return to the dining table, seriously endangering people's health. Therefore, it is of great significance to solve the problem of food waste and grease safely and properly. Studies have shown that compared with sugars and proteins, oil has higher methane-producing pote...

AI Technical Summary

Problems solved by technology

[0004] Direct anaerobic fermentation for biogas production has attracted more and more attention because of its simple process, but direct anaerobic fermentation is prone to long fermentation period due to the poor water solubility of oil; the intermediate product of oil metabolism, long-chain fatty acid (LCFA), is often Accumulate in the system and have an inhibitory effect on anaerobic microorganisms, especially in the UASB anaerobic digestion reactor, which is easy to cause the collapse of the anaerobic digestion system