The production and distribution of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in liquid

gas and solid three-phase products from sewage sludge pyrolysis from 350 to 1050℃ were studied. The results show that PAHs tend to be concentrated in liquid product

then into gaseous and solid products. The mass ratio of 16 kinds of PAHs contained in liquid product reaches the highest value 96% at 650℃. 16 kinds of EPA-PAHs in liquid products are all detected out. The mass ratio of ∑16PAHs in gas phase products at 750℃ reaches the highest value

21.3%. The content of PAHs in solid product is very low

which is 1%. At all the targeted pyrolysis temperatures

2

3 and 4 rings of PAHs occupied a leading position in the resulting products. The mass ratio of ∑2

3

4 rings of PAHs was over 95%

and the highest content of EPA-PAHs in liquid phase products is 15.25 mg·kg-1 at 850℃. In the gas phase

it mainly contains naphthalene (NaP)

acenaphthylene (Acp)

fluorene (Flu) and anthracene (Ant)

and the high ring of PAHs are not detected out. During a high temperature sludge pyrolysis

the thermos-chemical reaction of large molecular structure reaches a peak

along with the functional-groups decomposition

synthesis

and cyclization reactions

the concentration of ∑low PAHs in gas product reached 7.248 mg·kg-1. The variation of PAHs TEQ in the pyrolysis products from different temperatures basically agrees their concentration distributions. The TEQ of PAHs in the liquid product is up to 1.129 at 850℃.