Biomass gasification process, and apparatus, and their applications

The invention relates to a new and efficient staged gasification process characterized by a close integration of the gas cleaning part. The unit and process use a new device named Total Char Combustion and Tar Cracking Chamber (TCC)<2> positioned between a pyrolysis unit (PYR) and a char reduction reactor (CRC), in a stage divided gasifier. The char conversion takes place in 2 steps. In the first step, the char produced in the pyrolysis unit (PYR) is introduced in the (CRC) whose main purpose is to convert as much as possible carbon of the char. The (CRC) belongs to the fluidized bed type. The second step takes place in the (TCC)<2> whose purpose is to perform both a complete conversion of the remaining carbon still present after reaction in the (CRC); and the thermal cracking of the tar contained in the pyrolysis gases, the residual ashes being vitrified simultaneous and eliminated as a slag. Low grade feedstock with low melting point ashes can be used: straw and bark. A new vibrofluidized pyrolysis unit is implated to achieve an appropriate and constant quality of char with a minimum preparation of the biomass, and offers the opportunity to orientate the process for gas or solid. The invention leads to the following advantages: higher tolerance toward different quality of feedstocks including low grade feedstocks; recovery of the residual carbon content in ashes; production of a clean gas (low residual tar, ashes and alkali) for a direct injection in an engine/turbine. These results will induce a higher efficiency of the process and consequently bring to maturity the gasification technology.