(309d) Reaction Engineering of Catalytic Fast Pyrolysis: Current Status and Opportunities

The current state-of-the-art in the reaction engineering of catalytic fast pyrolysis (CFP) from a multiscale perspective is reviewed along with challenges and opportunities for filling knowledge gaps. Utilization of locally produced grapefruit processing waste (GPW) as a feedstock for conversion into various value-added chemicals using both biochemical routes and CFP will be discussed as an application. Critical aspects of process intensification using catalytic fast pyrolysis of lignocellulosic Rio Red GPW over small-pore (H-CHA, H-CHA (HS), H-ZK-5, H-rho), medium-pore (ZSM-5), and large-pore (H-Y (US)) zeolites at pressures up to 450 psi in a lab-scale system will be presented. The combined effects of temperature, heating rate, contact mode, catalyst to biomass ratio, residence time, and total pressure on the yield of target aromatic, furanic, phenolic, and polycyclic aromatic hydrocarbon (PAH) molecules were quantified using a Plackett-Burman experimental design approach. The effect of reaction parameters on the yield of various aromatics and other organic products show that value-added platform molecules can be produced from the GPW.

A key challenge in the commercialization of CFP process technologies is the development of kinetic models that capture the sub-millisecond transient evolution of products from the vaporizing solid biomass. Current methods for analyzing the pyrolysis vapors are delayed in detection by the order of seconds so that the sub-millisecond time-scale evolution of the intermediate and stable pyrolysis reaction products cannot be mapped. Efforts at developing a novel method and device for detecting the intermediate and final organic products during CFP in real time on a sub-millisecond time-scale are presented. Experiments using the high energy light source at the Paul Scherr Institute suggest that this device has the potential to provide the data needed to create reaction kinetic models that are fundamental to the development of reliable process scale-up strategies and also for optimization of pyrolysis oil production.