Integrated recycling system for co-hydrothermal preparation of oil with sludge and microalgae and culture of microalgae with waste liquid

Abstract

The invention discloses an integrated recycling system for co-hydrothermal preparation of oil with sludge and microalgae and culture of microalgae with waste liquid. The system comprises a microalgaeculture device and a hydrothermal liquefaction reactor. The cultured microalgae are adopted as the raw material and are compounded with sludge in proportion, then the mixture is input into the hydrothermal liquefaction reactor, the liquid phase in the pyrolysis product of the hydrothermal liquefaction reactor is input into the microalgae culture device and mixed with sewage in proportion, then themixture is used as the microalgae culture raw material, thus purifying sewage and avoiding the discharge of carbon, nitrogen and phosphorus elements in the liquid phase. The system provided by the invention has high economic, environmental and social benefits, is effectively applicable to treatment of urban sludge treatment with growing industry and can produce considerable economic and environmental benefits.

Description

technical field [0001] The invention belongs to the technical field of microalgae, and in particular relates to an integrated recycling system for sludge, microalgae co-hydrothermal oil production and waste liquid cultivation of microalgae. Background technique [0002] Municipal sludge is a by-product in the process of urban sewage treatment. At present, the sludge treatment and disposal problems are facing the following challenges: 1) With the increase of population and the improvement of urbanization level, the continuous expansion of sewage treatment plants, the output of urban sludge has increased year by year, increasing The speed is obvious. In 2005, the output of urban sludge was only 11.08 million tons, and the current sludge output has exceeded 50 million tons; 2) The moisture in the sludge is not easy to remove, and the moisture content is still as high as 80% after mechanical dehydration. Landfill, composting, incineration, etc. The traditional treatment methods...

AI Technical Summary

Problems solved by technology

In 2005, the output of urban sludge was only 11.08 million tons, and the current sludge output has exceeded 50 million tons; 2) The moisture in the sludge is not easy to remove, and the moisture content is still as high as 80% after mechanical dehydration. Landfill, composting, incineration, etc. The traditional treatment methods of municipal sludge all need to dry and dehydrate the sludge until the water content is below 60%, 40% and 30% respectively. The high drying cost leads to the sludge treatment and disposal costs can account for 10% of the operating costs of sewage treatment plants. 50% or so; 3) Municipal sludge has a high content of organic matter, its dry basis calorific value can reach 20MJ kg-1 and contains heavy metals and refractory toxic pollutants. There is a secondary pollution problem

A large amount of this wastewater is discharged into the environment, which will not only cause environmental pollution, but also be a waste of nutrients

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