Employment of Radioactive Tracers in the Hydrodynamic Definition of the Thermal Liquefaction Unit Dissolver. Topical Report No. 4

摘要

To characterize thermal liquefaction unit dissolver hydrodynamics for the majority of Wilsonville's Integrated Two-State Liquefaction data-base, the residence time distribution (RTD) of the slurry phase was measured using radioactive tracers, at 25% dissolver volume and with bituminous coal feed. The experimental RTD data was fitted to various mathematical models including tanks-in-series, cross flow, tanks-in-parallel, and partial solid ''slip'' models. The effects of gas superficial velocity, reactor temperature, coal feed rate, and solvent-to-coal ratio, on the degree of backmixing and slurry phase mean residence time were studied. Two different tracers were used at baseline conditions to determine the effect of tracer type on residence time distribution (RTD) of the slurry phase. Estimates of gas holdup were computed from the experimental measurements of mean residence time. The effect of gas superficial velocity on gas holdup was determined. The baseline experimental data was extrapolated, based on theoretical considerations, to estimate the degree of backmixing at 50% and 75% dissolver volumes. 23 refs., 33 figs., 7 tabs. (ERA citation 11:018988)