Enrico Biagini

Biomass gasification: experimental and modelling activities at CRIBE

Biomass gasification can be operated in various reactor configurations and under different operating conditions. The process is versatile as for biomass input as well as for the product (electricity, cogeneration, syngas, hydrogen, Fischer-Tropsch fuels) and it is an option to promote distributed power generation. Despite this technology was proposed and studied starting from the mid 20 th century, it is still not widespread due to some technological barriers that need to be addressed [1]. The major technological barriers can be classified in two groups:

Development of an integrated procedure for comprehensive gasification modelling

Biomass gasification is an attractive process to convert a solid fuel into a gaseous product. Although gasification is a relatively old process, the versatility of the process (with production of syngas, electricity, hydrogen or chemicals) and the multiplicity of technological solutions (fixed beds, moving beds, fluidized beds and entrained flow reactors) make it a current topic of investigation. In spite of all these differences, most process studies in the literature modeled the gasifier as an equilibrium reactor (see for instance [1]). This approach is indeed fundamental for a preliminary study but hardly suitable for process analysis and optimization procedures. A detailed approach allows the operating conditions to be related with a heat balance and introduce a thermal profile. Also by-products in the syngas (e.g., CH4 and CO2) and residual char and tar, that are generally underestimated in equilibrium models, can be quantified on the basis of the operating conditions. Finally, a detailed model can simulate each step of the gasification according to the gasifer configuration for the specific optimization. Therefore a “gasifier model” should be developed instead of a “gasification model”. So, the aim of this work is the development of a procedure for modeling different gasifiers and show some examples of gasifier models.