Biomass is widely regarded as a potential renewable energy resource of “CO2 zero emission” and is especially important in developing countries (often more than 90% in developing countries but 10-15% all around world), and more and more attentions have been focused on biomass utilization under the conditions of global warming and energy shortage [1, 2]. Now, over 2 billion of the population living in families using biomass to cook every day in the world [3], even though the traditional small-scale stoves degrades air quality and is thermally inefficient,