Between the molecular
and reactor scales, which are familiar to
the chemical engineering community, lies an intermediate regime, here
termed the “mesoscale,” where transport phenomena and
reaction kinetics compete on similar time scales. Bioenergy and catalytic
processes offer particularly important examples of mesoscale phenomena
owing to their multiphase nature and the complex, highly variable
porosity characteristic of biomass and many structured catalysts.
In this review, we overview applications and methods central to mesoscale
modeling as they apply to reaction engineering of biomass conversion
and catalytic processing. A brief historical perspective is offered
to put recent advances in context. Applications of mesoscale modeling
are described, and several specific examples from biomass pyrolysis
and catalytic upgrading of bioderived intermediates are highlighted.
Methods including reduced order modeling, finite element and finite
volume approaches, geometry construction and import, and visualization
of simulation results are described; in each category, recent advances,
current limitations, and areas for future development are presented.
Owing to improved access to high-performance computational resources,
advances in algorithm development, and sustained interest in reaction
engineering to sustainably meet societal needs, we conclude that a
significant upsurge in mesoscale modeling capabilities is on the horizon
that will accelerate design, deployment, and optimization of new bioenergy
and catalytic technologies.