Absolute and per-capita energy consumption is bound to increase globally, leading to a projected increase in energy requirements of 50% by 2020. The primary source for providing a majority of the energy will continue to be fossil fuels. However, an array of enabling technologies needs to be proven for the realization of a zero emission power, fuel or chemical plants in the near future. Opportunities to develop new processes, driven by the regulatory requirements for the reduction or elimination of gaseous and particulate pollutant abound. This presentation will describe the chemistry, reaction mechanisms, particle technology, system engineering, process economics, and regulations that surround the modern utilization of fossil energy. The presentation will illustrate the salient features pertaining to the fundamental and applied characteristics of the state-of-the-art technologies in practice as well as emerging technologies in development. Emerging technologies evolve largely from the urge for CO2 emission control in fossil energy conversion systems. Further, novel gasification systems based on the chemical looping concepts as well as the calcium looping process for CO2 separation from the combustion flue gas stream will be elucidated in the context of the looping particle design, process heat integration, energy conversion efficiency and economics.