Research On Three Phase Products In Sludge Pyrolysis Process

The total sewage discharge is sustained growth in our country, the sewage(mainly refers to the urban sewage) share rising trend, Amount of residual activated sludge produced in the process of sewage treatment is also more and more. Sewage treatment process of activated sludge moisture content is high, and contains a lot of pathogenic microorganism and parasite eggs, heavy metals, humus, poisonous and harmful material such as organic pollutants. If you can’t put these by-products produced in the process of sewage treatment and effective disposal, it will cause more serious secondary pollution.This experiment using self-made continuous feed type sludge pyrolysis test in experimental apparatus for the experiment. Operating conditions for the continuous feeding type sludge pyrolysis device(terminal temperature pyrolysis, material residence time) were studied. To seek the change rule of three-phase product in different operating conditions.Research has shown that different terminal temperature pyrolysis is a product of sludge pyrolysis three-phase influence decisive factors, different pyrolytic temperature directly affect the production rate of three-phase product, different terminal temperature conditions the yield of the product gas phase increased, the change of liquid product are rising after falling trend, in the 550 ℃ maximum oil production rate(40.45%).As the change of the terminal temperature pyrolysis of sludge in the solid phase product material decomposition, and then to BET specific surface area, surface functional groups of solid product features may also be affected, the terminal temperature in different conditions, the gas liquid two phase product composition also have great change, using GC/MS analysis found that with the increase of pyrolysis final temperature, methane content of gas phase with pyrolysis temperature rises, a component of a liquid product types under different terminal temperature pyrolysis is relatively fixed, mainly are aliphatic compounds, aromatic compounds, heterocyclic compounds, etc.; But to a greater influence on the relative content of each composition, at low temperature(300 ℃ ~ 600 ℃) are mainly composed of aliphatic compounds, the relative content over 70%, the high temperature period of aromatic compounds is given priority to, relative content in more than 40%.Pyrolysis time balance of the pyrolysis reaction of a factor, such as liquid product yield increased gradually before balance, the balance after the longer duration of pyrolysis production rate gradually decreased; In addition, pyrolysis time on the surface of the solid phase product features may also be affected, for example, the solid phase product BET specific surface area with the increase of pyrolysis time gradually, but after a certain time fell sharply; Pyrolysis time on gas、liquid product component types is a little affected, to influence the relative content of two-phase product, is mainly due to the gas and liquid product, with the secondary pyrolysis decomposition.