a co 2 A method of synergistic gasification of sludge with sub/supercritical water

Abstract

The invention provides a method for gasifying sludge through a synergistic effect of CO2 and sub / super-critical water. The method comprises the following steps that S1, the sludge is placed in a reaction device, the CO2 is introduced into the reaction device, so that the inside of the reaction device is a carbon dioxide environment, and pressure maintaining is conducted at the pressure of 0-8 MPa; S2, the reaction device is heated, so that the temperature in the reaction device is higher than or equal to 350 DEG C, and the pressure is 8 MPa or above, so that the sludge is gasified in a carbon dioxide-super-critical water system. By adopting the technical scheme, greenhouse gas carbon dioxide is recycled while the harmful solid waste sludge is treated, a large amount of available biogas and bio-oil are generated, the gasification rate of the sludge and yield of synthesis gas are increased, the gasification efficiency is improved, and sludge biomass resources are efficiently recycled.

Description

technical field [0001] The invention belongs to the technical field of resources and environment, and in particular relates to a CO 2 A method for synergistic gasification of sludge with sub / supercritical water. Background technique [0002] Municipal sludge is a by-product produced in the process of sewage treatment. As the domestic sewage treatment volume in my country increases year by year, the amount of residual sludge also increases rapidly. Sludge contains a large amount of organic matter, with a dry weight organic matter content of 30-70%. Traditional disposal methods such as landfill, composting, and incineration not only have a low utilization rate of organic matter, but also produce secondary pollution. Therefore, the gasification technology with high organic matter utilization rate and low secondary pollution has attracted much attention. According to the classification of biomass gasification agents, the existing gasification technologies mainly include pyrolys...

AI Technical Summary

Problems solved by technology

[0013] However, because sludge is a kind of biomass with high water content, the pyrolysis gasification process requires high water content of sludge, and the dehydration of sludge needs to consume a lot of energy, and the pyrolysis gasification rate is not high , will also produce a large amount of tar (30%-40%) and carbon residue

In the process of gasifying sludge with air, a large amount of nitrogen enters the reaction system, which dilutes the concentration of combustible gas, reduces the calorific value of gasification gas, and reduces the gas output of methane in the gas, and the calorific value of methane is large. The calorific value of the gas is reduced, so the gasification efficiency is reduced

Images