Design and performance assessment of an in-house fabricated microreactor for enzyme-catalysed biodiesel synthesis

Figures & data

Table 1. Distribution of the chemicals per inlet of the microfluidic chip.

	Oil (mL)	Tert-butanol (mL)	Methanol (mL)	Lipase (mL)	Total volume (mL)
Inlet 1	17	51.7	0	1.3	70
Inlet 2	18	48.3	3.75	0	70

Figure 1. The fabricated T-shaped microreactor: (a) Autocad 2D drawing, (b) the machined design on the PMMA sheet, (c) the chip sealed with a laminated sheet, (c) the back side of the chip after further sealing and ferrules connections and (d) the front side of the chip.

Figure 2. Flow rate setup: (a) varying the height to change the inlet flow rates and (b) the inlet reservoirs (feed syringes).

Table 2. Flowrate measurements.

	Targeted vs. measured flow rates
Run No.	50 µL/min	100 µL/min	150 µL/min	200 µL/min	250 µL/min	300 µL/min
1	51	101	148	198	253	300
2	51	100	150	200	251	300
3	50	101	150	199	250	301
4	52	99	150	201	250	301
$\overline{\mathit{x}}\pm \mathit{\sigma }$	51$\pm$0.71	100.2$\pm$0.83	149.5$\pm$0.87	199.5$\pm$1.12	251$\pm$1.23	300.5$\pm$0.50

Figure 3. Calibration curve for methanol in tert-butanol solution.

Figure 4. The rate of reaction at different methanol concentration.

Figure 5. Lineweaver–Burk plot for the enzymatic reaction.

Figure 6. Representation of V_max obtained for current work compared to previously published works.

Table 3. Comparison between current work and previous work.

Michaelis-Menten Model constants	Previous work				Current work
	Zarejousheghani, Kariminia, and Khorasheh (2016)	Krishna and Karanth (2001)	Al-Zuhair et al. (2009)	Azócar et al. (2014)
Vmax (mol/L.min)	0.268	0.012	0.002	0.018	0.725
KM (mol/L)	3397	3060	0.11	1030	0.092

Table 4. Reaction rate comparison with references used Michaelis–Menten model to study the kinetics of lipase-based biodiesel production.

Lipase type	Microbial source	Vmax (mol/L.min)	Ref
Fungi	Thermomyces lanuginous	0.725	Current work
Bacteria and fungi: Novozym 435	Commercial	$6.38\times {10}^{-4}$	Encinar et al. (2019)
Fungi	Thermomyces lanuginous	1.397	Gojun et al. (2019)

Zarejousheghani, F., Kariminia, H. R., & Khorasheh, F. (2016). Kinetic modelling of enzymatic biodiesel production from castor oil: Temperature dependence of the Ping Pong parameters. The Canadian Journal of Chemical Engineering, 94(3), 512–517. doi:10.1002/cjce.22408

 Web of Science ®Google Scholar

Krishna, S. H., & Karanth, N. G. (2001). Lipase-catalyzed synthesis of isoamyl butyrate: A kinetic study. Biochimica et Biophysica Acta - Protein Structure and Molecular Enzymology, 1547, 262–267. doi:10.1016/S0167-4838(01)00194-7

 Google Scholar

Al-Zuhair, S., Dowaidar, A., & Kamal, H. (2009). Dynamic modeling of biodiesel production from simulated waste cooking oil using immobilized lipase. Biochemical Engineering Journal, 44, 256–262. doi:10.1016/j.bej.2009.01.003

 Web of Science ®Google Scholar

Azócar, L., Navia, R., Beroiz, L., Jeison, D., & Ciudad, G. (2014). Enzymatic biodiesel production kinetics using co-solvent and an anhydrous medium: A strategy to improve lipase performance in a semi-continuous reactor. New Biotechnology, 31, 422–429. doi:10.1016/j.nbt.2014.04.006

 PubMed Web of Science ®Google Scholar

Encinar, J. M., González, J. F., Sánchez, N., & Nogales-Delgado, S. (2019). Sunflower oil transesterification with methanol using immobilized lipase enzymes. Bioprocess and Biosystems Engineering, 42, 157–166. doi:10.1007/s00449-018-2023-z

 PubMed Web of Science ®Google Scholar

Gojun, M., Pustahija, L., Tušek, A. J., Šalić, A., Valinger, D., & Zelić, B. (2019). Kinetic parameter estimation and mathematical modelling of lipase catalysed biodiesel synthesis in a microreactor. Micromachines, 10, 759. doi:10.3390/mi10110759

 PubMed Web of Science ®Google Scholar