A comparative analysis and assessment of dual fluidized bed and chemical looping gasification: Design considerations for commercial use and applicability in BTL schemes

Indirect biomass gasification systems have become an attractive option for syngas production, due to their extended fuel flexibility as well as the avoidance of costly, energy demanding oxygen production units (Air Separation Unit). The most dominant representative technologies of indirect gasification are Dual Fluidized Bed Gasification (DFBG) and Chemical Looping Gasification (CLG). DFBG is a semi-commercially proven technology (Güssing, Ulm, Gothenburg), while CLG has just been demonstrated at pilot scale (TU Darmstadt). Within this work, process simulations of steam gasification with DFBG and CLG at pilot scale are performed in Aspen PlusTM and the results are validated against available experimental data. Using the validated pilot models as a basis, upscaling considerations and large-scale simulations are carried out. The performance of the technologies is assessed in terms of thermodynamic efficiency (i.e. cold gas efficiency), syngas quality, carbon utilization, as well as their impact on the process downstream (e.g. tars removal, CO₂ capture). The main objective of the present study is to investigate the operational characteristics of two promising indirect gasification technologies in order to evaluate their technical specifications and financial parameters, their commercialization potential as well as their appropriateness for Biomass-to-Liquid (BtL) applications.