Combustion of butanol isomers – A detailed molecular beam mass spectrometry investigation of their flame chemistry

详细信息    查看全文

• 作者：Patrick Oß ; wald ; Hanna Gü ; ldenberg ; Katharina Kohse-H&#xf6 ; inghaus ; Bin Yang ; Tao Yuan ; Fei Qi
• 关键词：Butanol flame ; Combustion intermediates ; Molecular beam mass spectrometry ; Bio-butanol combustion
• 刊名：Combustion and Flame
• 出版年：2011
• 出版时间：January 2011
• 年：2011
• 卷：158
• 期：1
• 页码：2-15
• 全文大小：887 K

文摘

The combustion chemistry of the four butanol isomers, 1-, 2-, iso- and tert-butanol was studied in flat, premixed, laminar low-pressure (40 mbar) flames of the respective alcohols. Fuel-rich ( = 1.7) butanol–oxygen–(25 % )argon flames were investigated using different molecular beam mass spectrometry (MBMS) techniques. Quantitative mole fraction profiles are reported as a function of burner distance. In total, 57 chemical compounds, including radical and isomeric species, have been unambiguously assigned and detected quantitatively in each flame using a combination of vacuum ultraviolet (VUV) photoionization (PI) and electron ionization (EI) MBMS.

Synchrotron-based PI-MBMS allowed to separate isomeric combustion intermediates according to their different ionization thresholds. Complementary measurements in the same flames with a high mass-resolution EI-MBMS system provided the exact elementary composition of the involved species. Resulting mole fraction profiles from both instruments are generally in good quantitative agreement.

In these flames of the four butanol isomers, temperature, measured by laser-induced fluorescence (LIF) of seeded nitric oxide, and major species profiles are strikingly similar, indicating seemingly analog global combustion behavior. However, significant variations in the intermediate species pool are observed between the fuels and discussed with respect to fuel-specific destruction pathways. As a consequence, different, fuel-specific pollutant emissions may be expected, by both their chemical nature and concentrations.

The results reported here are the first of their kind from premixed isomeric butanol flames and are thought to be valuable for improving existing kinetic combustion models.