Pironi, Paolo and Switzer, Christine and Rein, Guillermo and Fuentes, Andres and Gerhard, Jason I. and Torero, Jose L. (2009) Small-scale forward smouldering experiments for remediation of coal tar in inert media. Proceedings of the Combustion Institute, 32 (2). pp. 1957-1964. ISSN 1540-7489
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This paper presents a series of experiments conducted to assess the potential of smouldering combustion as a novel technology for remediation of contaminated land by water-immiscible organic compounds. The results from a detailed study of the conditions under which a smouldering reaction propagates in sand embedded with coal tar are presented. The objective of the study is to provide further understanding of the governing mechanisms of smouldering combustion of liquids in porous media. A small-scale apparatus consisting of a 100 mm in diameter quartz cylinder arranged in an upward configuration was used for the experiments. Thermocouple measurements and visible digital imaging served to track and characterize the ignition and propagation of the smouldering reaction. These two diagnostics are combined here to provide valuable information on the development of the reaction front. Post-treatment analyses of the sand were used to assess the amount of coal tar remaining in the soil. Experiments explored a range of inlet airflows and fuel concentrations. The smouldering ignition of coal tar was achieved for all the conditions presented here and self-sustained propagation was established after the igniter was turned off. It was found that the combustion is oxygen limited and peak temperatures in the range 800-1080 °C were observed. The peak temperature increased with the airflow at the lower range of flows but decreased with airflow at the higher range of flows. Higher airflows were found to produce faster propagation. Higher fuel concentrations were found to produce higher peak temperatures and slower propagation. The measured mass removal of coal tar was above 99% for sand obtained from the core and 98% for sand in the periphery of the apparatus.
|Notes:||This paper introduced the concept of smouldering of a liquid within an inert porous medium. This paper is the culmination of about 18 months of work to demonstrate the concept of liquid smouldering and presents the findings to a combustion audience. A series of small scale experiments are presented and visual tracking of smouldering is linked to observed temperature propagation. The PCI represents one of the highest impact factor journals within the fire community. This work was presented at the International Symposium on Combustion and received much praise.|
|Keywords:||NAPL, technology, clean-up, soil, smoldering, civil engineering, Mechanical engineering and machinery, Chemical technology, Environmental technology. Sanitary engineering|
|Subjects:||Technology > Mechanical engineering and machinery|
Technology > Chemical technology
Technology > Environmental technology. Sanitary engineering
|Department:||Faculty of Engineering > Civil and Environmental Engineering|
|Depositing user:||Dr Christine Switzer|
|Date Deposited:||03 Dec 2009 14:17|
|Last modified:||17 Jan 2013 07:16|
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