Hydrogen Combustion and Emissions in a Sustainable Energy Future

Abstract

The global energy landscape is undergoing a transformation driven by rising energy demand, diminishing fossil fuel supplies, deregulation of energy industry, and growing concern about climate change. While fossil fuels will continue to play a dominant role in meeting the current and future energy needs, there is worldwide interest in developing renewable and alternative energy sources to meet the growing energy demand and address concerns about the emission of greenhouse gases and hazardous pollutants. In this context, hydrogen is viewed as a viable renewable energy carrier due to its abundant supply, superior emission characteristics, and flexibility in harnessing its energy through a variety of technologies. There are, however, many technological and scientific issues pertaining to its production, storage, and utilization. This chapter provides an overview of such issues and discusses research dealing with hydrogen combustion and emissions in the context of sustainable energy future. Studies concerning laminar flames, including non‐premixed, premixed, and partially premixed flames in various configurations, and also those dealing with ignition and extinction phenomena, are reviewed. High‐pressure phenomena including explosions/ignition limits are discussed, and an overview of detonation and turbulent combustion is provided. Issues pertaining to hydrogen combustion and emissions in practical systems are also discussed. Further technological advances and fundamental research needed for hydrogen to play a major role in the sustainable energy future are identified.

Ignition characteristics of heptane–hydrogen and heptane–methane fuel blends at elevated pressures

“…For the 100%H 2 case, the important reactions are R90, R91, R70, R96, and R89. These reactions, which involve species such as H 2 O 2 , HO 2 , H 2 , OH, etc., are known to be associated with H 2 ignition, and have been extensively discussed, particularly in the context of H 2 explosion and ignition limits, by several researchers; see, for example, Law and coworkers [51,52], Briones et al [53], and Aggarwal and Briones [54]. For the case with 5% n-C 7 H 16 in the blend, the relative importance of these reactions decreases appreciably, while reactions R12, R4, R71, R25, and R6 become important.…”