Laminar burning velocities and flame characteristics of COeH 2 eCO 2 eO 2 mixtures Jinhua Wang a,b, *, Zuohua Huang a, *, Hideaki Kobayashi b , Yasuhiro Ogami b a State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, PR China b Institute of Fluid Science, Tohoku University, Sendai, Miyagi 980-8577, Japan article info Article history: Received 21 May 2012 Received in revised form 19 July 2012 Accepted 20 July 2012 Available online 22 October 2012 Keywords: Laminar burning velocity Syngas Oxyfuel combustion Flame radiation Flame instability abstract Laminar burning velocities of COeH 2 eCO 2 eO 2 flames were measured by using the outwardly spherical propagating flame method. The effect of large fraction of hydrogen and CO 2 on flame radiation, chemical reaction, and intrinsic flame instability were investigated. Results show that the laminar burning velocities of COeH 2 eCO 2 eO 2 mixtures increase with the increase of hydrogen fraction and decrease with the increase of CO 2 fraction. The effect of hydrogen fraction on laminar burning velocity is weakened with the increase of CO 2 fraction. The Davis et al. syngas mechanism can be used to calculate the syngas oxyfuel combustion at low hydrogen and CO 2 fraction but needs to be revised and validated by additional experimental data for the high hydrogen and CO 2 fraction. The radiation of syngas oxyfuel flame is much stronger than that of syngaseair and hydro- carbonseair flame due to the existence of large amount of CO 2 in the flame. The CO 2 acts as an inhibitor in the reaction process of syngas oxyfuel combustion due to the competition of the reactions of H þ O 2 ¼ O þ OH, CO þ OH ¼ CO 2 þ H and H þ O 2 (þM) ¼ HO 2 (þM) on H radical. Flame cellular structure is promoted with the increase of hydrogen fraction and is suppressed with the increase of CO 2 fraction due to the combination effect of hydrody- namic and thermal-diffusive instability. Copyright ª 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 1. Introduction With ever increasing of energy demand and concern of envi- ronmental protection, the researches on clean alternative power system have attracted an increasing attention in recent years. The developed Integrated Gasification Combined Cycle (IGCC) technology can achieve higher efficiency and lower emissions. The IGCC power plants will allow the gasification of wide range of liquid and solid fuel or waste to convert into syngas mixtures which can be used in the gas turbine to generate electricity [1]. The syngas can also be used as fuel of other combustion devices such as internal combustion engines and/or cooking appliance [2]. The IGCC Polygenera- tion technology can produce electricity, hydrogen, chemical products and liquid fuels simultaneously, thus it is a very promising technology in the future. One of the most impor- tant advantages of IGCC technology is that it has the potential to realize zero CO 2 emissions when it is extended to carbon capture and storage (CCS) technique [3]. There are several ways for CCS, the oxyfuel combustion which burns the fuel in oxygen rather than air with recycled flue gas is one of the most promising options [4,5]. For the oxyfuel combustion, the * Corresponding authors. State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, PR China. Fax: þ86 29 82668789. E-mail addresses: jinhuawang@mail.xjtu.edu.cn (J. Wang), zhhuang@mail.xjtu.edu.cn (Z. Huang). Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 37 (2012) 19158 e19167 0360-3199/$ e see front matter Copyright ª 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijhydene.2012.07.103