Experimental Study of Synthesis Gas Combustion Chemistry and Ignition Behaviors.

Syngas;Iso-octane;Rapid compression facility;Strong and weak ignition;Impurity;Trimethylsilanol;Mechanical Engineering;Engineering;Mechanical Engineering

Mansfield, Andrew BenjaminIm, Hong G. ;

University of Michigan

关键词: Syngas;    Iso-octane;    Rapid compression facility;    Strong and weak ignition;    Impurity;    Trimethylsilanol;    Mechanical Engineering;    Engineering;    Mechanical Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/110478/amansfld_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The development of synthesis gas (syngas) fuel is of interest, as it can enable a transition from fossil to renewable energy sources while reducing the emissions associated with both.Historical research has focused on basic syngas formulations (H2 & CO) in homogeneous environments, providing a baseline for consideration of more realistic mixtures and devices. Recent research and industrial experience for syngas fueled combustors indicate the effects of common disturbances can be dramatic and are not well-understood, with particular concern regarding the occurrence of uncontrolled inhomogeneous auto-ignition and its effect on the accuracy of common homogeneous reactor modeling.This dissertation represents an experimental investigation of syngas combustion, aimed at comprehensively understanding the effects of specific chemical and physical disturbances at high-pressure low-temperature conditions.Experiments were conducted in the University of Michigan-Rapid Compression Facility.The auto-ignition behaviors of syngas were investigated, revealing the existence of both homogeneous and inhomogeneous characteristics depending strongly on the initial unburned thermodynamic state.The behaviors were mapped over a wide range of conditions revealing consistent patterns.It was discovered that the Sankaran Criterion, a previously proposed relationship between chemical kinetics, transport properties, and known thermal disturbances, could predict the location of inhomogeneous behavior on these maps with remarkable accuracy.This provides evidence that commonly ignored thermal disturbances can cause uncontrolled inhomogeneous auto-ignition in syngas and also provides a straightforward method to predict such behavior.As expected, inhomogeneous auto-ignition behavior was well correlated to error in homogeneous reactor modeling for higher energy content mixtures.The effects of chemical impurities on the combustion of syngas were investigated, focusing on CH4, a common component of syngas, and trimethylsilanol (TMS), an unstudied impurity related to those common to landfill-based syngas.The impact of CH4 was to inhibit ignition, evidenced by auto-ignition delay time increases by up to a factor of 3. Conversely the impact of TMS was to promote ignition, causing drastic reductions in auto-ignition delay time up to 70%.These large promotion effects have significant safety implications, as pronounced early auto-ignition can lead to catastrophic failures and concentrations of similar Si containing species are expected to increase in the future.