1 Introduction
2 Background
3 System configurations
4 Process model
4.1 Mass balance of a separation column
4.2 Adsorption isotherms
4.3 Counter current chromatography (TMB and SMB)
4.4 Incorporation of the racemization reactor
4.5 Modeling of the solvent removal unit
4.6 Modeling of the feed and desorbent tanks
4.7 Model implementation
5 Process evaluation
5.1 Productivity, solvent consumption and yield
5.2 Identifying favorable operating SMB conditions
6 Two case studies
6.1 Case study 1: Mandelic acid enantiomers
Parameter | Symbol | Value | Unit |
---|---|---|---|
Fresh feed conc. | \(c_{i,\mathrm{{F0}}}\) | 2, 7.5, 20 | (g/L) |
Chromatographic separation | |||
Quadratic AI | \(q_{\mathrm{{s}}}\) | 4.7 | (g/L) |
(Eq. (11)) | \(b_{\mathrm{{1}}}\) | 0.060 | (g/L) |
\(b_{\mathrm{{2}}}\) | 0.0137 | (g/L) | |
\(H_{\mathrm{{1}}}\) | 0.282 | (g/L) | |
Linear (Eq. (10)) | \(H_i\) | 0.6938 | (–) |
Column length | \(L_{\mathrm{{c}}}\) | 150 | (mm) |
Column porosity | \(\epsilon _{\mathrm{{t,c}}}\) | 0.65/0.61 | (–) |
C. plate number | \(N_{\mathrm{{p}}}\) | 100 | (–) |
Selectivity | \(\alpha _{\mathrm{{c}}}\) | 2.44 | (–) |
Batch chromatography | |||
Flow rate | \(Q_{\mathrm{{batch}}}\) | 0.5 | (mL/min) |
Cycle time E1 | \(\Delta t_{\mathrm{{1,cyc}}}\) | 3.55 | (min) |
Cycle time E2 | \(\Delta t_{\mathrm{{2,cyc}}}\) | 4.62 | (min) |
TMB chromatography | |||
Solid phase flow rate | \(Q_{\mathrm{{s}}}\) | 1 | (mL/min) |
Racemization reactor | |||
Reaction rate | \(r_{\mathrm{{reactor}},i}\) | \(\inf\) (Eq. (28)) | (g/min/\(\hbox {m}^{\mathrm {3}}\)) |
Solvent removal unit | |||
Split ratio | \(\alpha _{\mathrm{{SR}}}\) | Adj. | (–) |
Recovery rate | \(REC_{\mathrm{{SC}}}\) | 1 | (–) |
6.2 Case study 2: Methionine enantiomers
7 Results and discussion
CS | Process mode | \(c_{i,F}\) | \(m_{\mathrm{{II}}}\) | \(m_{\mathrm{{III}}}\) | Target | \(PR_i\) | \(SC_i\) | \(PUR_i\) | |
---|---|---|---|---|---|---|---|---|---|
Raff. | Extr. | \(\left( \frac{g}{kg\cdot day} \right)\) | \(\left( \frac{L}{kg} \right)\) | \((\%)\) | |||||
1 | Batch Chrom.a | 20 | – | – | x | 208.7 | 887.5 | 99.50 | |
20 | – | – | x | 161.1 | 1150.0 | 99.50 | |||
1 | 4Z-SMB | 7.5 | 0.45 | 0.65 | x | 57.5 | 464.7 | > 99.95 | |
7.5 | 0.58 | 0.80 | x | 74.5 | 195.5 | > 99.90 | |||
20 | 0.10 | 0.65 | x | 485.5 | 38.0 | > 99.95 | |||
20 | 0.58 | 0.77 | x | 198.6 | 72.3 | > 99.95 | |||
1 | 3Z-SMB | 7.5 | 0.45 | 0.65 | x | 76.8 | 918.5 | > 99.90 | |
7.5 | 0.58 | 0.80 | x | 99.3 | 195.6 | 100 | |||
20 | 0.10 | 0.65 | x | 647.4 | 91.9 | > 99.95 | |||
20 | 0.58 | 0.77 | x | 264.8 | 72.3 | 100 | |||
2b | 4Z-SMB | 7.5 | 0.2 | 1.2 | x | 515 | 450 | > 99.50 | |
7.5 | 1.0 | 1.6 | x | 395 | 560 | > 99.50 |
7.1 Operational region for stand-alone 4Z-SMB
7.2 4Z-SMB chromatography with integrated racemization (CS1)
7.3 Batch and 4Z-SMB chromatography (CS1)
7.4 Comparison of CS1 and CS2
7.5 Applying an integrated open-loop 3Z-SMB unit
7.6 High process performance for production of E1
8 Conclusions
Symbol | Variables | Units |
---|---|---|
\(c_i\) | Conc. of component i in liquid phase | g/L |
\(q_i\) | Loading of component i onto stationary phase | g/L |
Symbol | Parameters | Units |
---|---|---|
\(\alpha _{\mathrm{{c}}}\) | Chromatographic separation factor | – |
\(\alpha _{\mathrm{{SR}}}\) | Split factor of solvent removal unit | – |
\(\epsilon _{\mathrm{{t,c}}}\) | Porosity of chromatographic column | – |
\(\nu _{i}\) | Stoichiometric coefficient | – |
\(b_{i,\mathrm {1}}\) | Adsorption isotherm coefficient | L/g |
\(b_{i,\mathrm {2}}\) | Adsorption isotherm coefficient | \(\hbox {L}^{\mathrm {2}}\)/\(\hbox {g}^{\mathrm {2}}\) |
\(D_{\mathrm{{app}}}\) | Apparent dispersion | m/\(\hbox {s}^{\mathrm {2}}\) |
\(F_{\mathrm{{c}}}\) | Phase ratio | – |
HETP | Height of an equivalent theor. plate | – |
\(K_i\) | Henry constant of component i | – |
\(L_{\mathrm{{c}}}\) | Column length | m |
\(m_{\mathrm{{z}}}\) | Dimensionless flow rate of zone z | – |
\({\dot{m}}_i\) | Through put | g/d |
N | Number of components | – |
\(N_{\mathrm{{col}}}\) | Number of columns | – |
\(N_{\mathrm{{p}}}\) | Number of theoretical plates | – |
\(PR^*_i\) | Productivity of component i | g/L/d |
\(PR_i\) | Productivity of component i | g/kg/d |
\(PUR_i\) | Purity of component i | % |
\(Q_{\mathrm{{ext}}}\) | Inlet and outlet of liquid phase | L/day |
\(Q_{\mathrm{{s}}}\) | Flow rate of solid phase | mL/min |
\(Q_{\mathrm{{z}}}\) | Flow rate of liquid phase in zone z | L/day |
\(q_{\mathrm{{s}}}\) | Saturation capacity | g/L |
\(REC_{\mathrm{{SR}}}\) | Recovered ratio | % |
\(SC_i\) | Solvent consumption | kg/L |
t | Time variable | min |
\(\Delta t_{\mathrm{{i,cyc}}}\) | Cycle time of component i | min |
\(u_{\mathrm{{z}}}\) | Interstitial velocity of liquid phase | m/min |
\(u_{\mathrm{{s}}}\) | Velocity of solid phase | m/min |
\(V_{\mathrm{{c}}}\) | Column volume | mL |
\(V_{\mathrm{{cell}}}\) | Single cell volume | mL |
\(V_{i,\mathrm {inj}}\) | Injection volume | mL |
\(V_{\mathrm{{SR}}}\) | Volume of solvent removal unit | mL |
\(V_{\mathrm{{tank,D}}}\) | Desorbent tank volume | mL |
\(V_{\mathrm{{tank,F}}}\) | Feed tank volume | mL |
x | Space variable | m |
\(Y_{i}\) | Process yield | % |
Symbol | Indices | Range |
---|---|---|
z | Cone number | \({\text{I,}} \ldots ,{\text{IV}}\) |
i | Number of component | 1,2 |
D | Desorbent inlet | |
D,0 | Fresh desorbent | |
E | Extract port | |
F | Feed inlet | |
F,0 | Fresh feed inlet | |
R | Raffinate port | |
rac | Racemate port | |
rec | Recycled stream | |
tot | Component 1 + 2 | |
perm | Permeate stream |