Pilot scale catalytic fast pyrolysis of biomass: Leveraging CFD modeling to enable commissioning of an FCC riser unit

The scaling of biomass thermo-catalytic conversion technologies faces a variety of interesting engineering, chemistry, and materials challenges. The biomass feedstock can be best described as Velcro coated needles, which of course provides ample challenges in the solids feeding system. Once inside the heated reactor system, one must deal with multiple solids (sand, char, biomass, catalyst), liquid (aerosols), and gas (products, reactive intermediates, co-reactants) phases, heat and mass transport of non-ideal geometries, all while balancing complex chemistries (pyrolysis vs. catalytic upgrading) and residence times. Many of the parameters and correlations needed to evaluate such system are either missing (e.g. catalytic kinetics) or inadequate for the biomass paradigm.

In this poster we will detail the design, construction, and commissioning of an FCC riser unit for biomass catalytic fast pyrolysis (CFP). This riser system is operated in an ex situ arrangement, in which the pyrolysis and char separation occur in a separate, upstream reactor so that the riser unit can focus on the catalytic upgrading (e.g. deoxygenation) of the pyrolysis vapor stream. Specifically, we will focus on the commissioning stage of this system, the challenges that arose, and how computational fluid dynamics (CFD) helped to guide the engineering solutions of those challenges. Finally, we will describe the first application of this system, which was to validate so-called ‘reactor agnostic’ catalyst kinetics for CFP.