Oily sludge catalytic pyrolysis combined with fine particle removal using a Ni-ceramic membrane

Abstract

Pyrolysis is one of the effective technology for oily sludge treatment and energy recovery. However, pyrolysis of oily sludge generates solid particles which are taken away from the reactor by gas, causing blockage in downstream equipment and reducing the quality of pyrolysis oil and gas. A study on the clean catalytic pyrolysis of oily sludge was carried out, by incorporating a ceramic membrane with or without Ni inside the pyrolysis reactor. It aims to investigate the effect of ceramic membrane on oily sludge pyrolysis and particulate removal. The yield of the pyrolysis gas produced from the reaction with Ni-ceramic membrane is 31.46 L/kg, while the recovery rate of pyrolysis oil is 48.21%. On the contrary, the yield of the pyrolysis gas produced from the reaction with blank ceramic membrane is 17.92 L/kg, while the recovery rate of pyrolysis oil is 62.63%. The particulate matter content in gas without and with Ni-ceramic membrane are 2.74 and 0.07 mg/L. The particulate matter content in oil without and with Ni-ceramic membrane are 3708.9 and 156.7 mg/L, respectively. Results indicated that the Ni catalyst loading on the ceramic membrane could improve the yield of the pyrolysis gas and remove the fine particles effectively. In addition, a long-time catalytic pyrolysis experiment was carried out, with the feeding speed of 4.17 g/min and the reaction temperature of 500 °C. It was found from the set conditions that the Ni-ceramic membrane could be used continuously for 420 min.