Design and characterization of an entrained flow reactor for the study of biomass pyrolysis chemistry at high heating rates

A laminar entrained flow reactor has been designed for studying the chemist ry of fast biomass pyrolysis. This is the first of two papers on the reacti on system. Peak heating rates in the reactor are on the order of 10(4) K/s. The reactor is capable of interfacing with a molecular beam mass spectrome ter for rapid analysis of gas phase chemistry. Computational fluid dynamic simulations are used to predict an accurate time-temperature profile for th e reactants and to better understand the internal processes in the reactor. Predicted and measured reaction rates compare favorably for a gas phase re action standard. Particle devolatilization is modeled to help understand th e tradeoff between heat transport and kinetic control of the pyrolysis rate . Biomass and cellulose particles below about 50 mum are expected to be suf ficiently small to avoid heat transport pyrolysis control, and thus allow s tudy of kinetically controlled pyrolysis in this reactor. This paper is the first of two, and describes the characterization of the entrained flow rea ctor and methodologies developed for determining quantitative kinetic measu rements. The second paper describes the application of these techniques to the study of cellulose pyrolysis at high heating rates.