A process for producing biogas and recovering phosphorus by anaerobic fermentation of chicken manure

Abstract

The invention discloses a technology for producing marsh gas and recycling phosphorus in an anaerobic fermentation mode through chicken manure, and belongs to the field of solid organism waste energy regeneration and resource recycling. The technology includes the working procedures of marsh gas production through anaerobic fermentation, solid-liquid separation, gas-water separation, desulfuration purification, phosphorus recycling, biogas residue high-temperature reacting and slow-release compound fertilizer preparing. According to the technology, fermentation marsh gas production and nitrogen and phosphorus gathering are carried out with a three-level reverse flow technology, separated fermentation material liquid and biogas residuals reversely flow among anaerobic tanks in various levels, the suppression effect of high-concentration ammonia nitrogen generated in the chicken manure fermentation process on anaerobic microorganism is reduced, and meanwhile the marsh gas yield and the nitrogen and phosphorus concentration in the anaerobic fermentation material liquid are improved. Nitrogen and phosphorus are recycled with a magnesium ammonium phosphate crystallizing method, formed crystal products are added into the high-temperature reacted biogas residuals, and slow-release compound fertilizers with magnesium ammonium phosphate as main effective ingredients are prepared. Products generated with the technology are the clean energy marsh gas and the efficient slow-release compound fertilizers, and the chicken manure energy regeneration aim and the resource recycling aim can be achieved at the same time.

Description

technical field [0001] The invention discloses a process for producing biogas and recovering phosphorus by anaerobic fermentation of chicken manure, which belongs to the field of solid organic waste energy and resource utilization. [0002] technical background [0003] With the adjustment of my country's agricultural structure and the advancement of agricultural industrialization, the livestock and poultry breeding industry has changed from the original small-scale and scattered operations to large-scale and intensive production, resulting in a large number of pollutants such as livestock and poultry manure increasing year by year. Chicken manure occupies a relatively high proportion in the production of livestock and poultry manure. According to statistics, the production of chicken manure in my country is as high as 100,000 tons per day, and it is increasing rapidly year by year. Chicken manure is rich in organic matter. Untreated chicken manure has a high moisture conten...

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Problems solved by technology

[0008] The invention is aimed at the fact that chicken manure is rich in crude protein, and anaerobic fermentation alone will easily lead to the accumulation of ammonia nitrogen, which will inhibit the activity of microorganisms; however, the combined fermentation of chicken manure and other high-carbon organic waste can reduce the concentration of ammonia nitrogen produced in the fermentation process , but it leads to a decrease in the concentration of orthophosphate produced in the process, which is not conducive to the subsequent phosphorus recovery. A three-stage countercurrent technology is proposed for anaerobic fermentation to produce biogas and enrich nitrogen and phosphorus in the fermentation broth.

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