Method for preparing bio-oil through supercritical pyrolysis of civil sludge

Abstract

The invention discloses a method for preparing bio-oil through supercritical pyrolysis of civil sludge. The method comprises the steps of: directly putting sludge from a factory into a high-pressure sealed reaction vessel, and repeatedly purging to achieve inert atmosphere by adopting nitrogen gas; enabling water in the sludge as a raw material in the reaction vessel to reach a supercritical state through temperature programming and pressurization by nitrogen gas, so as to realize pyrolytic reaction of the sludge in the supercritical water; and obtaining pyrolyzed bio-oil after vacuum filtration, liquid separation, extraction and rotary evaporation of a reaction product. A disposal system adopting the method ,mainly comprises a sequencing batch type high-pressure sealed reaction vessel, a booster pump, a condenser, a rotary evaporator, vacuum pump and the like. By adopting the invention, the links of drying and dewatering of sludge in the conventional oil-making technology through low-temperature sludge pyrolysis are avoided, the problem of use of a great amount of catalysts in direct liquefaction and oiling technologies of sludge are broken through, at the same time, the problem of secondary pollution of heavy metal is also avoided, and the bio-oil with high added value can be obtained.

Description

technical field [0001] The present invention relates to solid waste treatment, in particular to a method for preparing bio-oil by supercritical pyrolysis of municipal sludge. Background technique [0002] At present, sludge treatment methods mainly include agricultural use, landfill and incineration. With the gradual exposure of the drawbacks of traditional treatment methods, the utilization of sludge resources has been paid more and more attention. Among them, the pyrolysis and liquefaction technology of sludge has been well developed. Pyrolysis and liquefaction of organic waste is a resource utilization method, the main purpose is to obtain the liquid fuel with the highest yield and highest calorific value. Sewage sludge, like most organic wastes, contains a lot of volatile organic compounds, and the energy stored in the sludge can be released in the form of fuel through pyrolysis. It can be seen from the above discussion that the sludge pyrolysis and liquefaction technol...

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Problems solved by technology

[0016] The purpose of the present invention is to provide a method for supercritical pyrolysis and liquefaction of municipal sludge to solve the problems of high disposal cost and complicated pretreatment of existing sludge pyrolysis oil production technology, so as to obtain high value-added bio-oil and recover Solid semi-coke and flammable pyrolysis gas

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