Pyrolysis characteristics and products distribution of petroleum sludges

ABSTRACT

Pyrolysis can realise the harmlessness, reduction and resource utilisation of petroleum sludge in a short period. In the present work, a tank bottom sludge (SSOS) and a landing sludge (SLOS) from Shengli Oilfield were used for experimental research. Thermogravimetric testing is used to initially determine the optimal range of pyrolysis temperature. Pyrolysis experiments were performed in a tube furnace reactor. Pyrolysis products were collected and analysed separately. The char yield of SSOS and SLOS were 50% and 70%, respectively. Although there are differences in the oil content of the two types of petroleum sludge, the oil yield remained nearly the same, which were both between 7% and 8%. As the pyrolysis temperature was raised to 500°C, the yield of each product did not change greatly while their composition had obvious changes. High temperature is more conducive to the production of small molecule products. Result showed that pyrolysis treatment of petroleum sludge can effectively recover energy materials in the form of pyrolysis gas and oil. The heating value of char is lower than that of petroleum sludge, which means that char is not suitable for direct use as fuel. Pyrolysis treatment also showed good curing effect on Cr, which reached 85%. However, the solidification effect decreased as pyrolysis temperature increasing. It is necessary to pay attention to the heavy metal contained in char as soil improver. The rich surface structure of char provides evidence to produce high value-added carbon materials.

GRAPHICAL ABSTRACT

KEYWORDS:

• Petroleum sludge
• pyrolysis
• char
• pyrolysis gas
• pyrolysis oil

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors gratefully acknowledge the financial supports from the State Key Laboratory of Pollution Control and Resource Reuse foundation [grant number PCRRF19023]; Key Research and Development Program of Liaoning Province [grant number 2020JH2/10300099] and Fundamental Research Funds for the Central Universities [grant number 18CX02150A]. They also thank the State Key Laboratory of Heavy Oil in China University of Petroleum (East China).