Yuan Tian
University of Northern British Columbia, Canada
Title: Co-pyrolysis of synthetic oily waste containing heavy metals: Influence of operational conditions on the oil recovery and heavy metal immobilization
Biography
Biography: Yuan Tian
Abstract
This work proposes an alternative method for the safe disposal of metal-contaminated oily waste, generated during petroleum extraction. Co-pyrolysis of synthetic oily waste and hog fuel was conducted in a fixed bed reactor. Three experimental parameters (pyrolysis temperature, holding time, and hog fuel addition) were explored to optimize both oil recovery and metal immobilization. Using sequential extraction techniques, it was found that the distribution of metal ions in the various extraction fractions varied greatly with pyrolysis temperature. The higher the temperature, the more the metal ions existed in the non-bioavailable fraction. This is evident from the risk index (RI) for eco-toxicity assessment with a RI=34.63 at 600℃ compared to a RI=117.14 at 400℃. In contrast, the maximum of oil recovery was achieved at a low co-pyrolysis temperature (400℃). The addition of hog fuel had a significant synergistic effect on the redistribution of metal ions infractions resulting in lower RI values but reduced the overall oil recovery. Considering the effectiveness of hog fuel addition in the heavy metal ions immobilization at a low pyrolysis temperature (RI=54.12 at 400℃), a low-temperature co-pyrolysis (400℃) using 20% of hog fuel with less energy consumption is deemed the most effective strategy for metal-containing oily waste disposal.