Small-scale forward smouldering experiments for remediation of coal tar in inert media

Paolo Pironi, Christine Switzer, Guillermo Rein, Andres Fuentes, Jason I. Gerhard, Jose L. Torero

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

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.
LanguageEnglish
Pages1957-1964
Number of pages8
JournalProceedings of the Combustion Institute
Volume32
Issue number2
DOIs
Publication statusPublished - 2009

Fingerprint

smoldering
Coal Tar
Coal tar
tars
Remediation
coal
Sand
sands
Ignition
Experiments
ignition
propagation
Quartz
igniters
Thermocouples
Organic compounds
Temperature
Porous materials
thermocouples
organic compounds

Keywords

  • NAPL
  • technology
  • clean-up
  • soil
  • smoldering
  • civil engineering

Cite this

Pironi, Paolo ; Switzer, Christine ; Rein, Guillermo ; Fuentes, Andres ; Gerhard, Jason I. ; Torero, Jose L. / Small-scale forward smouldering experiments for remediation of coal tar in inert media. In: Proceedings of the Combustion Institute. 2009 ; Vol. 32, No. 2. pp. 1957-1964.
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Small-scale forward smouldering experiments for remediation of coal tar in inert media. / Pironi, Paolo; Switzer, Christine; Rein, Guillermo; Fuentes, Andres; Gerhard, Jason I.; Torero, Jose L.

In: Proceedings of the Combustion Institute, Vol. 32, No. 2, 2009, p. 1957-1964.

Research output: Contribution to journalArticle

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