Date of Award

9-29-2017

Document Type

Thesis

Department

Civil and Environmental Engineering

First Advisor

G.R. Johnson

Subjects

Biomass -- Combustion, Biomass energy -- Mathematical models, Renewable energy sources, Hemp -- Application to biomass energy

Subject Categories

Energy Systems | Sustainability

DOI

10.15760/honors.483

Abstract

As knowledge concerning the consequences of unsustainable energy sources and agricultural practices grows, development of low-impact alternatives to both becomes more important. Sustainable sources of biomass offer solutions to both problems. This study characterized the reaction kinetics of torrefying an agricultural byproduct, the woody interior of hemp stems, or hurds. Torrefaction was carried out at 250 °C in small and simple retorts made of galvanized steel pipe. A first-order model most closely approximated the reaction. A sensitivity analysis was performed and the data was adjusted to correct for three potential sources of error, and regressed to find the best fit in each case. When corrected for torrefaction time, initial moisture content, and final mass loss, the best fit regressions for mass loss with time yielded governing equations L = 0.5388 × (1 − e-0.003069(+113) ), L = 0.4523 × (1 − e-0.003015t), and = 0.4088 × (1 − e-0.008718t), respectively. Regression of uncorrected data gave the governing equation = 0.5388 × (1 − e-0.004682t). Results of this study indicate that the conversion of hemp hurds via torrefaction follows first-order reaction kinetics and that reaction is most sensitive to the torrefaction time under fixed-bed, isothermal conditions.

Comments

A thesis submitted in partial fulfillment of the requirement for the degree of Bachelor of Science in Civil and Environmental Engineering

Persistent Identifier

http://archives.pdx.edu/ds/psu/22530

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