Progress in combustion investigations of hydrogen enriched hydrocarbons

Due to industrial development and population growth, global demand for energy has increased enormously; the increased consumption of primary sources of energy such as coal, oil and natural gas has exerted a strong influence on the atmospheric environment. Among all the alternative fuels, hydrogen offers the greatest potential benefits to energy supply and the environment However, combustion of pure hydrogen is challenged by the difficulties in production, storage, and end-use. A more reasonable method to enhance combustion is to use hydrogen as an additive to fossil fuels. This paper presents a comprehensive review of recent progress in fundamental investigations of hydrogen enriched combustion. A broad range of topics on fundamental combustion of hydrogen/hydrocarbon mixtures are discussed. The minimum ignition energy of hydrogen/hydrocarbon blends shows significant decrease with the increased hydrogen fraction X-H2. With an increase of the hydrogen fraction, ignition behavior of hydrogen/hydrocarbon fuel blends exhibits three distinct behaviors. Additionally, the laminar flame speed of hydrogen/hydrocarbon fuel blends is found to exhibit three behavior regimes. Furthermore, the flame front instability behavior is influenced by the hydrogen addition through the combined effect of body force, the hydrodynamic effect and the thermal-diffusion effect (C) 2013 Elsevier Ltd. All rights reserved.