Method and system for producing biodiesel by cultivating microalgae by using urban sewage

Abstract

The invention relates to a method and a system for producing biodiesel by cultivating microalgae by using urban sewage. According to the method and the system, a sewage treatment system is converted from a treatment technique to a production technique; high contents of organics and nutrients such as nitrogen and phosphorus in the urban sewage are conducive to mass propagation of the microalgae, so that the sewage is converted from pollutants to raw materials for the growth of the microalgae; CO2 circulation and O2 circulation are tightly combined through the establishment of an algal-bacterial symbiotic system, so that the growth of the microalgae is no longer dependent on an external carbon source, and meanwhile, the production cost is low due to the reduction of aeration systems in an aeration tank; the illumination in the aeration tank is abundant due to the use of a photosynthesis component, which is conducive to the photosynthesis of the microalgae; and the subsequent sludge quantity is small due to the use of efficiently-degraded strains.

Description

Technical field [0001] The invention relates to a method and system for producing biodiesel, in particular to a method and system for producing biodiesel by using urban domestic sewage to cultivate microalgae. Background technique [0002] The energy crisis is related to the future development of mankind, so the development of new energy has attracted more and more attention. Another major crisis parallel to the energy crisis is the crisis of water resources and water quality. The shortage of fresh water resources is one of the main bottlenecks restricting my country's future development. Sewage recycling is an important way to solve this problem, and water eutrophication control is the primary problem that needs to be solved when recycled water is reused in landscape waters. Therefore, in the secondary and tertiary treatment of sewage treatment plants, it is necessary to efficiently remove nitrogen and phosphorus in sewage. Using municipal sewage to cultivate high-fat microal...

AI Technical Summary

Problems solved by technology

These processes require the use of non-stop to feed O 2 , did not solve the problems of high energy consumption and large amount of residual sludge in the aeration equipment of the sewage treatment plant. At the same time, there were some limitations, such as the low content of nutrients such as nitrogen and phosphorus in the secondary effluent, which is not conducive to the growth and reproduction of microalgae. It cannot penetrate to the bottom of the microalgae growth reaction device, which is not conducive to the photosynthesis of microalgae, and the carbon source that the exhaust gas of the power plant can provide is limited

As a result, it is difficult to realize the industrialization of using urban domestic sewage to cultivate high-fat microalgae to produce biodiesel

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