(432b) Modeling the Impact of Biomass Particle Residence Time on Fast Pyrolysis Yield and Composition
Numerous studies have demonstrated that biomass fast pyrolysis yields depend on the residence time distribution (RTD) of the pyrolyzing particles, which is a function of the inherent feed properties as well as the reactor design and operating conditions. Experimental measurements indicate that it should be possible to represent the RTDs for biomass particles in both bubbling and circulating bed pyrolysis reactors with relatively simple functional approximations involving only two or three physically relevant parameters. We expect similar approaches can also be used to model the impact of catalyst particle residence time in vapor phase upgrading reactors.
In this presentation, we summarize literature on low-order reactor models for the particle RTDs in bubbling and circulating fluidized bed reactors and discuss the implications for the conversion of biomass particles undergoing fast pyrolysis. Based on this information, we demonstrate how particle RTDs can be combined with reaction kinetics and simplified reactor mass balances to create low-order fast pyrolysis models that can be used to summarize, interpret, and extrapolate observed pyrolysis trends in experiments and more detailed computational simulations. Our goal is to provide flexible analytical tools for consolidating information from more detailed computational reactor simulations and improving high-level process simulations of bio-oil production needed for techno-economic analyses and reactor design.