Effect of Recirculation Gases on Soot Formed from Ethylene Pyrolysis

Abstract

Flue gas recirculation (FGR) is an effective technology both to control NO_x emissions during combustion processes and to control temperature and make-up for the volume of the missing N₂ during oxy-fuel combustion processes. In this article, a study of the individual role of the main products that are expected to form part of the recycled flue gas (CO, H₂, H₂O, and CO₂) on soot and gas products formed during the thermal decomposition of ethylene-additive gas mixtures in the 975–1475 K temperature range is reported. Experimental results obtained in a quartz flow reactor are examined with the main objective of assessing the effectiveness of each gas additive in suppressing or boosting soot formation. Additionally, experimental data have been interpreted in terms of a literature detailed gas-phase kinetic model to analyze the evolution of gas products and get a better understanding of the gas-phase processes involving the thermal decomposition of the ethylene-additive gas mixtures, although soot formation reactions are not included in such mechanism.

Keywords:

• Combustion phenomena
• Reacting flows
• Thermochemistry

ACKNOWLEDGMENTS

The authors express their gratitude to the the Diputación General de Aragón (DGA) and Fundación La Caixa (Project DGA-LE031/2009) for financial support. Ms. M. Abián acknowledges University of Zaragoza and GPT Research Group for the pre-doctoral grant awarded.

Notes

*Experimental data taken from a previous work (Abián et al., 2012).

Published as part of the Seventh Mediterranean Combustion Symposium Special Issue with Guest Editors Federico Beretta, Nevin Selçuk, Mohy S. Mansour, and Andrea D'Anna.