Continuous production of β-cyclodextrin by cyclodextrin glycosyltransferase immobilized in mixed gel beads: Comparative study in continuous stirred tank reactor and packed bed reactor

2016 ◽  
Vol 105 ◽  
pp. 107-113 ◽  
Author(s):  
Jaruporn Rakmai ◽  
Benjamas Cheirsilp
2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Kashyap Kumar Dubey ◽  
Dhirendra Kumar ◽  
Punit Kumar ◽  
Shafiul Haque ◽  
Arshad Jawed

Bioconversion of colchicine into its pharmacologically active derivative 3-demethylated colchicine (3-DMC) mediated by P450BM3 enzyme is an economic and promising strategy for the production of this inexpensive and potent anticancer drug. Continuous stirred tank reactor (CSTR) and packed-bed reactor (PBR) of 3 L and 2 L total volumes were compared for the production of 3-demethylated colchicine (3-DMC) a colchicine derivative using Bacillus megaterium MTCC*420 under aerobic conditions. Statistical optimization technique was utilized with the most significant variables, that is, dissolved oxygen (DO), colchicine concentration, and process time for optimization. The validation of the model was performed by experiments on the predicted values in an individual run, and the optimum parameters were DO (~50%), colchicine concentration (7.5 g/L), and process time (39 h) resulted in a maximum bioconversion of 3-DMC 3.36 g/L. The PBR reactor achieved much higher productivity (6.58 g/L/h) as reported by earlier researchers. This is the first report on the use of PBR for bioconversion of colchicine.


2021 ◽  
Vol 17 (2) ◽  
pp. 181-194
Author(s):  
Fadzil Noor Gonawan ◽  
Azlina Harun Kamaruddin

The continuous-stirred-tank reactor (CSTR) is favorable for bi-phasic enzymatic reaction due to ease of operation, cost-effective and low downtime. Lack of study on the enzymatic reaction in the CSTR has disfavor this type of reactor compared to batch and packed bed. Presently, a simulation was carried out to simulate the behavior of the lipase-catalyzed production of biodiesel by using CSTR at isothermal conditions. The mathematical model incorporated the effect of the kinetic, thermal, and operating parameters. The parameters such as Michaelis constant (Km), inhibition constant (Ki), Gibbs inactivation energy (DelG) and mol flow rate are among determining factors of the course of the reaction. It is suggested that the enzyme with lower , higher , and higher  should be chosen for the reaction. In continuous operation in the CSTR, the volumetric flow rate of the substrates and the initial concentration of the feed could be used to control reaction performance as these parameters will determine the total mol or ratio of the substrates in the reactor. Most, importantly, the longer residence time is preferred to achieve higher conversion, however, the volumetric flow rate must not be too low to prevent underperformance of reaction.


2020 ◽  
Vol 10 (3) ◽  
pp. 992 ◽  
Author(s):  
Juan P. Castillo Gónzalez ◽  
Peggy E. Álvarez Gutiérrez ◽  
Manuel Adam Medina ◽  
Betty Y. López Zapata ◽  
Gerardo V. Ramírez Guerrero ◽  
...  

Continuous production processes and an adequate supply of raw materials are necessary to satisfy the growing demand for biodiesel. The use of different feed oils could be necessary to ensure sufficient supply for biodiesel production in certain circumstances; however, changing feed oil during the operation of a continuous reactor causes process disturbances. The present study analyses the effect of feed oil changes on the continuous operation of a industrial continuous stirred-tank reactor (CSTR) using a model which takes the dynamics of oil changes into account. The models previously reported only consider the operation of reactor with only one vegetable oil. The model in this work was developed by mass and energy balances. A methodology to model oil changes is presented. Glycerides and esters were characterized using adequate approaches. Moreover, accurate methods for predicting essential properties in the biodiesel manufacturing were used for the estimation of their thermo-physical properties. The kinetic parameters of the transesterifications were calculated from consistent studies selected from an exhaustive literature revision. The results show that temperature is practically not affected after oil changes; however, the ester concentration varies considerably. The ester mass fraction varying by up to 22.07% after an disturbance.


2021 ◽  
Vol 6 (3) ◽  
pp. 459-464
Author(s):  
Ioannis Lignos ◽  
Yiming Mo ◽  
Loukas Carayannopoulos ◽  
Matthias Ginterseder ◽  
Moungi G. Bawendi ◽  
...  

Multistep and continuous production of core–shell InP/ZnS semiconductor nanocrystals in a high-temperature and miniature continuous stirred-tank reactor cascade.


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