Research on Composition Characteristics of the Pyrolysis Products from Karamay Oily Sludge Based on Tg-Ftir-Gcms

Abstract

Karamay oily sludge was taken as the research object, and the combined analytical apparatus, composed of thermogravimetric analyzer, Fourier-transform infrared spectrometer and gas chromatograph coupled to mass spectrometer (TG-FTIR-GCMS), was used to analyze weight loss behavior and composition characteristics of the pyrolysis products at different temperatures. At the heating rates of 20 oC/min and 50 oC/min, the results of thermogravimetric (TG) and infrared (FTIR) test showed that temperatures of the obvious three weight loss rate peaks moved to higher temperature direction with the increasing of heating rate, and the relative content of functional groups in the pyrolysis products from oily sludge is more complex and diverse. Specifically, the relative content of ether bonds is higher, while the content of characteristic functional groups of benzene and its derivatives is lower. At the heating rate of 20 oC/min, composition characteristics of the pyrolysis products from oily sludge was investigated as the temperature rose to 280 oC, 470 oC and 700 oC (the corresponding temperatures of the three maximum weight loss rate peaks). Comparing the product distribution at 280 oC and 470 oC (the product at the temperature of 700 oC is not compared since only CO2 was detected), it is found that the higher the temperature is, the relative content of C1-C10 is higher, while the relative content of chain alkanes and alcohols is lower. And the relative content of olefins is also increased, up to 21.09%. Therefore, with the increase of temperature, some bonds in the pyrolysis products may break and recombine, from long chain to short chain. And the content of oxygen-containing organic derivatives decreases from 26.58% to 9.2%, which might be derived from cracking and deoxygenation during the pyrolysis process.

Keywords: Oily sludge, Pyrolysis, Product composition, TG-FTIR-GCMS