The
vapor-phase cracking of 4-vinylguaiacol has been investigated
in a nonisothermal, laminar-flow reactor at temperatures between 300
and 900 °C and a residence time of one second. Products identified
by gas chromatography were oxygenated compounds such as phenols, cresols,
furans, ketones, and aldehydes, single-ring and polycyclic aromatic
hydrocarbons, C1–C6 hydrocarbon gases,
and carbon monoxide. Temperature had a marked effect in governing
the overall product composition. Conversion of 4-vinylguaiacol to
products increased above 400 °C and was completed at 550 °C.
Reaction rate parameters derived from the conversion data were A = 1013 s–1 and E
a = 45.3 kcal mol–1. The oxygenated
compounds were observed as products in the range 450–800 °C,
peaking in yields below 700 °C. The aromatic hydrocarbons and
light gases dominated the product composition above 600 °C, especially
at 900 °C, the highest temperature investigated. On the basis
of the experimental data showing the effect of temperature on product
composition, reaction pathways leading to products formation are proposed.
Lumped kinetics for
the vapor-phase cracking of 4-propylguaiacol,
a model compound representative of components found in primary tar
derived from lignin, has been investigated. Analysis of the products
from pyrolysis experiments in a laminar-flow reactor at temperatures
between 300 and 900 °C and a residence time of 1 s revealed that
the products can be lumped into three compound classes: oxygen-containing
compounds, single- and multiring aromatic hydrocarbons, and permanent
gases. Temperature was found to have a marked effect in governing
the overall product composition. The oxygen-containing compounds peaked
in yield between 500 and 700 °C. The aromatic hydrocarbons and
permanent gases dominated the product composition above 600 °C,
especially at 900 °C, the highest temperature investigated. A
lumped kinetic model with three irreversible first-order reactions
was developed to model the experimental data. This model was extended
to one with eight first-order irreversible reactions. Optimized reaction-rate
parameters for each reaction in both models were determined by fitting
the experimental data using a plug-flow reactor model.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.