Study on Co-combustion Kinetics of Oil Shale Sludge and Semicoke

Abstract

Experiments on combustion of oil shale sludge and semicoke were conducted on TG-FTIR to investigate the mechanism of co-combustion involved. The synergy effect of sludge and semicoke was estimated by using the interaction coefficient and the relative error of mean square root. In addition, the activation energy was calculated by means of Coats–Redfern, DAEM, FWO, and Starink. The results show that the whole process contains three stages: light components combustion (130–350 °C), heavy components and volatiles co-combustion (350–650 °C), and fixed carbon combustion (650–750 °C). During the combustion, synergy behaves differently with variation of mixing proportion in mixture and heating rates. DTG curves of mixtures can be decomposed into five Gaussian fitting peaks, respectively corresponding to five independent parallel reactions. From the results of Coats–Redfern, one can see that the kinetic triplets are related to mixture proportion, combustion stage, and heating rate. In addtion, the results of DAEM,...