abstract
In this work, a simulated moving bed unit (SMB) was designed for the separation of betulinic and oleanolic acids, two naturally occurring triterpenic acids that exhibit key pharmacological properties. Preliminary impulse experiments were conducted to select appropriate mobile and stationary phases, from which methanol/acetonitrile 50/50 (%, v/v) and an Apollo C18 column emerged as the most favorable option. Breakthrough experiments were conducted with the pure compounds to determine the equilibrium and mass transfer coefficients necessary for SMB simulations. These parameters were then validated through the successful prediction of breakthrough experiments of two binary mixtures of betulinic and oleanolic acids. Optimum SMB operating conditions were determined via an optimization strategy combining the design of experiments and response surface methodologies (DoE-RSM) with phenomenological computer simulations. It was demonstrated that an SMB unit consisting of two columns per section allows the recovery of betulinic acid in its raffinate stream with a purity of 99.0 % and oleanolic acid in the extract stream with 99.4 % purity. Moreover, it was also demonstrated that the addition of acetonitrile to methanol is translated into a gain of 16.1 % in terms of productivity when compared to other mobile phase such as methanol/water 95/5 (%, v/v).
keywords
SIMULATED MOVING-BED; SUPERCRITICAL-FLUID EXTRACTION; ANTIINFLAMMATORY ACTIVITY; FOREST BIOREFINERY; BIOMASS RESIDUES; OUTER BARKS; DESIGN; OPTIMIZATION; ENERGY; PULP
subject category
Engineering
authors
Azenha, IS; Aniceto, JPS; Sequeira, SP; Mendes, A; Silva, CM
our authors
Carlos Manuel Silva
Associate Professor
Ivo Samuel Caniceiro Azenha
PhD Student
José P. S. Aniceto
Junior Researcheracknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES and when applicable cofinanced by FEDER under the PT2020 Partnership Agreement, and the Multibiorefinery project (POCI-01-0145-FEDER-016403). I.S. Azenha acknowledges a PhD grant from Fundacao para Ciencia e a Tecnologia (Portugal) (grant number SFRH/BD/126509/2016) and financial support of Project POCI-01-0145-FEDER-006939 (Laboratory for Process Engineering, Environment, Biotechnology and Energy LEPABE funded by FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Intemacionalizacab (POCI). The authors would also like to thank Monica Valega (University of Aveiro) for the continuous help with the HPLC setup.