Solar gasification of biomass in a dual fluidized bed

A new approach to conduct allothermal steam-gasification of biomass in a dual fluidized bed gasifier (DFBG), using concentrating solar energy and solid particles as thermal energy carrier and storage media, is presented. The advantage of this configuration is that the solar receiver and the reactor are uncoupled, while thermal integration is highly efficient since carrier particles are directly used in the reactor. A model of the proposed system is developed and used to theoretically analyze the performance of the solar DFBG (SDFBG) under various configurations. The circulation of solids and the solar heat supply to the system are compared for different arrangements. The separation and storage of char is identified as a method to provide the system with significant flexibility. Moreover, the operation under daily and seasonal weather variations throughout the year is studied by the developed model coupled to a solar field using hourly data from a specific location. Overall, the results indicate the huge scale-up potential of this new solar gasification technology in the short to medium term. Major challenges for developing the technology are identified and discussed.

Automated summary

A new approach utilizing concentrating solar energy and solid particles as thermal energy carrier and storage media for allothermal steam-gasification of biomass in a dual fluidized bed gasifier is presented. The study shows the significant flexibility provided by the separation and storage of char in the system. Results indicate the huge scale-up potential of this new solar gasification technology in the short to medium term.