Gasification process analysis and reactor realization - A new integrated approach of coal gasification

During coal gasification process, the reaction rate varies with coal conversion and temperature. After conversion reaches certain value (> 75%), the reaction rate decreases as reaction advances. But in all cases, the reaction rate increases exponentially with temperature. According to this characteristic and chemical engineering principle, a new integrated gasification concept --fluidized bed +entrained flow is introduced in this paper. Within this process, large partition of coal with higher reactivity is converted in fluidized bed reactor under moderate temperature (similar to 1000 degrees C) and the remaining small partition of coal with lower reactivity is converted in entrained flow gasifier under-higher temperature (similar to 1400 degrees C). It is kinetic and energy favored and in the meantime low carbon content ash can be withdrawn in dry mode with no difficulty for entrained flow gasifier under the situation of coal with high ash content and high melting point. Preliminary experimental results show that the whole facility can be operated steadily and produce favorable gas, by which prove the concept correct and feasible.