Oil recovery from oily-sludge by pyrolysis method

Pyrolysis characteristics of oily-sludge were studied by thermogravimetric(TG) analyzer and tubular furnace reactor. The effects of heating rates on oily-sludge pyrolysis and the effects of final pyrolysis temperature on the product distribution of oily-sludge pyrolysis were investigated. The kinetic parameters of oily-sludge were calculated with the method of Coats-Redfern. The products of oily-sludge pyrolysis were analyzed by elemental analysis, FT-IR and ¹H NMR. The results indicated that TG curve of oily-sludge shifted to higher temperature, and its activation energy(E) and pre-exponential factor(A) values were increased with the increase of the heating rates. The optimum final pyrolysis temperature was 823 K, at which the oil yield of oily-sludge pyrolysis reached its maximum value of 40.36%. The recovered oil had the similar chemical composition to diesel oil, which could be reused. The pyrolysis residues of oily-sludge were black powder solid and residual oil content in it was about 0.0662%, meeting the national standard regulation for farm-oriented soil oil content(<0.3%).