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Table 1 List of symbols. Dependent variables (Dep. Var.) refer to variables that are defined by or are calculated directly from experimental data

From: Investigating the effects of substrate morphology and experimental conditions on the enzymatic hydrolysis of lignocellulosic biomass through modeling

Symbol

Description

Value

Units

\({b}_{l}\)

Biomass loading

Dep. Var.

[g/cm3]

\({C}_{E,0}\)

Initial bulk enzyme concentration

Dep. Var.

[mol/cm3]

\({C}_{E}^{F}(r,t)\)

Enzyme concentration in pores or bulk (r = R)

Dep. Var.

[mol/cm3]

\({C}_{E}^{S}(r,t)\)

Enzyme concentration adsorbed at the cellulose surface per total cylinder volume V(r)

Dep. Var.

[mol/cm3]

\({C}_{E,max}^{S}(r,t)\)

Maximum enzyme concentration adsorbed at the cellulose surface per total cylinder volume V(r)

Dep. Var.

[mol/cm3]

\({D}_{E}^{eff}(r,t)\)

Effective cellulase diffusivity in pores

Dep. Var.

[cm2/min]

\({\stackrel{-}{D}}_{E}^{pore}\)

Average cellulase diffusivity in pores

Dep. Var

[cm2/min]

\({D}_{E}\)

Time independent part of the effective cellulase diffusivity in pores

Dep. Var.

[cm2/min]

\({e}_{l}\)

Enzyme loading in terms of enzyme:initial binding sites molar ratio

Dep. Var

[molE/molSites]

Hglu

Hydrolysis factor for glucose

0.9

[MMcellulose/MMglucose]

\({k}_{ads}\)

Cellulase surface adsorption rate [60]

\(3 \cdot {10^{10}}\)

[cm3/(mol \(\cdot\) min)]

\({k}_{des}\)

Cellulase surface desorption rate [42, 43]

\(0.068\)

[1/min]

\({M}_{p}\)

Average moles of glucose liberated in solution per mole of cellulase during one binding-reaction cycle

Fitted var.

[molglucose/moldesorbing enzyme]

\({MM}_{glu}\)

Molar mass of glucose

180

[g/mol]

\(n\)

Grid size

Dep. Var.

[−]

\({n}_{E,0}\)

Total number of moles of enzyme in the system

Dep. Var.

[mol]

\(r\)

Radial distance

Indep. Var.

[cm]

\(R\)

Particle radius

Dep. Var.

[cm]

\({S}_{c}\)

Pore cellulose surface

Dep. Var

[cm2]

\({S}_{cyl}\)

Outer particle surface

Dep. Var.

[cm2]

\(t\)

Time

Indep. Var.

[min]

\({V}_{B}\)

Volume of bulk solution

Dep. Var.

[cm3]

\(\varepsilon (r,t)\)

Porosity

Dep. Var.

[cm3pore/ cm3biomass]

\({\varepsilon }_{0}\)

Initial porosity

Dep. Var.

[cm3pore/ cm3biomass]

\({\rho }_{C}^{IV}\)

Density of cellulose including void

Dep. Var.

[g/cm3]

\(\varphi\)

Angular coordinate

Indep. Var.

[−]

\(\sigma\)

Maximum cellulase surface concentration on cellulose [42, 43]

\(2.1\cdot{10}^{-12}\)

[mol/cm2]

\(\tau\)

Tortuosity

Fitted var.,

[−]

z

Longitudinal coordinate

Indep. Var.

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