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Enzymatic reactor (Michaelis-Menten) simulation

1 inlet -> 1 outlet (substrate + pH-branched dual products)

Governing equations

The exact equations the solver works for a enzymatic reactor (michaelis-menten) — the same math shown in the app's "Theory" panel, not a black box.

v(S)=VmaxSKm+S(Michaelis-Menten)v(S) = \frac{V_{max}\,S}{K_m + S}\quad(\text{Michaelis-Menten})
SinSout=τv(Sout),τ=V/V˙S_{in} - S_{out} = \tau\,v(S_{out}),\qquad \tau = V/\dot V
Sout2Sout(SinKmτVmax)KmSin=0(positive root)S_{out}^2 - S_{out}\,(S_{in} - K_m - \tau V_{max}) - K_m S_{in} = 0\quad(\text{positive root})
flow=11+10pHpKa,fhigh=1flow(single-ionizable-group product switch)f_{low} = \frac{1}{1 + 10^{\,\mathrm{pH} - \mathrm{p}K_a}},\qquad f_{high} = 1 - f_{low}\quad(\text{single-ionizable-group product switch})
SS
substrate concentration [mol/m³]
SinS_{in}
substrate fed
SoutS_{out}
substrate leaving (and, in a CSTR, the concentration the reaction actually sees)
v(S)v(S)
reaction rate [mol/m³/s]
VmaxV_{max}
maximum rate when the enzyme is saturated [mol/m³/s]
KmK_m
Michaelis constant [mol/m³] — the substrate level at half V_max; low K_m means a tight-binding enzyme
τ\tau
residence time V/V̇ [s]
VV
reactor volume [m³]
V˙\dot V
volumetric flow [m³/s]
pH\mathrm{pH}
operating pH — here it selects *which* product forms
pKa\mathrm{p}K_a
pKa of the ionizable group doing the selecting
flow,fhighf_{low}, f_{high}
fraction of consumed substrate routed to each product pathway

Parameters

substrate (feed component), volume [m^3], vmax [mol/(m^3*s)], km [mol/m^3], ph, pka_switch [pH-dependent product-branching switch point]; optional product_low_ph [default 'product_low_ph'], product_high_ph [default 'product_high_ph'], pressure_drop [Pa]. Michaelis-Menten CSTR; substrate consumed splits between the two products via a single-ionizable-group pH-titration switch

Example flowsheets that use it

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