From primitive wood to nowadays fossil fuels such as coal, oil and natural gas, it can be seen that the forms of energy becomes more and more diverse and the core trend of decarburization is also obvious (the rate of the element of H to C ranging from 1/1 From primitive wood to nowadays fossil fuels such as coal, oil and natural gas, it can be seen that the forms of energy becomes more and more diverse and the core trend of decarburization is also obvious (the rate of the element of H to C ranging from 1/1