Please note that, due to the fact that different models use different nomenclature and units, the nomenclature is covered chapter-by-chapter. In most cases the symbols are also explained where they first appear in the text.

Chapter 3

Pr productivity (kg h-1 m-3)

tprocess time between successive harvests (h)

Vbioreactor bioreactor volume (m3)

Xharyest amount of biomass (or product) at the time of harvesting (kg) Xi„itiai amount of biomass (or product) at zero time (kg)

Chapter 4

Tsubscript temperature of phase or subsystem indicated by subscript (°C) Chapter 5

H superficial velocity of the air (m s-1)

Tsubscript temperature of phase or subsystem indicated by subscript (°C) Fz bed height (m)

Chapter 6

C O2 concentration in the surrounding atmosphere (g cm-3)

D effective diffusivity of O2 in the bed (cm2 h-1)

Dc critical tray depth (cm)

k thermal conductivity of the bed (W m-1 °C-1)

NBi Biot number

Rq volumetric heat production rate (W m-3)

RX overall growth rate (kg-dry-biomass m-3 h-1)

Rxm maximum growth rate (g-dry-biomass cm-3-bed h-1)

Ta surrounding air temperature (°C)

Ts bed surface temperature (°C)

X biomass density (kg-dry-biomass m-3)

Xmax maximum possible biomass density (kg-dry-biomass m-3)

YXO yield coefficient of biomass from O2 (g-dry-biomass g-O2-1)

z spatial coordinate as a dimensionless fraction of the total bed height

Z total bed height (m)

a coefficient for bed-to-air heat transfer at the bed top (W m-2 °C-1)

ab coefficient for bed-to-air heat transfer at the bed bottom (W m-2 °C-1)

H specific growth rate parameter (h-1)

© temperature difference between the bottom of bed and the tray surface when no heat transfer through the bottom of the tray (°C) jdFO fractional specific growth rate based on O2 (dimensionless) juFT fractional specific growth rate based on temperature (dimensionless) fjmilx maximum value that the specific growth rate parameter can have (h-1)

Chapter 8

Adscript area, with meaning indicated by subscript (m2) D drum diameter (m)

Fmix volumetric exchange rate between the dead and plug-flow regions relative to the drum volume and mean residence time (dimensionless) h coefficient for bed-to-headspace heat transfer (W m-2 °C-1)

NC critical rotational speed (rpm)

Rb ratio of exposed surface area of the bed to the bed volume (m-1)

Rconv rate of convective heat removal to the headspace gases (W) Tsubscript temperature of phase or subsystem indicated by subscript (°C) Vsubscript volume, with meaning indicated by subscript (m3) Qm angle subtended at the center of the drum by the bed surface for fractional filling ro (radians) ® fractional filling of the drum (m3-bed m-3-total-bioreactor-volume)

Chapter 11

F mass flow of fresh solids (kg h-1)

fm solids flow through well-mixed region (kg h-1)

fp solids flow through plug-flow region (kg h-1)

fR recycled solid-flow (kg h-1)

M overall mass of solids in the bioreactor (kg)

Mm mass of solids in the well-mixed region (kg)

Mp mass of solids in the plug-flow region (kg)

X biomass content in product and recycle streams (g kg-dry-matter1)

Xmax maximum possible biomass content (g kg-dry-matter1)

Xo initial biomass content in the fresh feed stream (g kg-dry-matter1)

Xo' biomass content after mixing the fresh feed and recycle streams (g kg-dry-matter-1)

a fraction of the flow that passes through the plug-flow region (fp/fm)

[i fraction of the "in-bioreactor" mass in the plug-flow region (Mp/Mm)

Y recycle ratio (dimensionless)

H specific growth rate parameter (h-1)

Chapter 12

a constant in the double-Arrhenius equation (h-1)

A area across which heat transfer takes place (m2)

b constant in the double-Arrhenius equation (dimensionless)

CPair heat capacity of dry air (J kg-dry-air-1 °C-1)

CPB C

^Pvapor

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