@article { ISI:000242285000001, title = {Comparative assessment of downstream processing options for lactic acid}, journal = {Separation and Purification Technology}, volume = {52}, number = {1}, year = {2006}, month = {NOV}, pages = {1-17}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The possibility of manufacturing a biodegradable polymer from lactic acid has led to extensive research in recovery of lactic acid produced by fermentation, by different downstream processing routes. This paper assesses the suitability of different downstream processing options such as reactive extraction, adsorption, electrodialysis, esterification and reactive distillation. It compares the costs of different process routes. The assessment indicates that the conventional precipitation of calcium lactate, followed by acidification, esterification and hydrolysis will be the most economical route although it generates large quantity of gypsum sludge. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Adsorption, electrodialysis, Esterification, Lactic acid, Reactive distillation, reactive extraction}, issn = {1383-5866}, doi = {10.1016/j.seppur.2006.03.015}, author = {Joglekar, H. G. and Rahman, Imran and Babu, Suresh and Kulkarni, B. D. and Joshi, Ajit} } @article { ISI:000268120200001, title = {Evaluation of repulsive particle swarm method for phase equilibrium and phase stability problems}, journal = {Fluid Phase Equilibria}, volume = {282}, number = {2}, year = {2009}, month = {AUG}, pages = {65-67}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Phase equilibrium and stability problems are of crucial importance in simulation, design and optimization of several separation processes. Recently, these problems have been solved using minimization of Gibbs free energy, using global optimization techniques. In this paper, repulsive particle swarm (RPS), a recent global optimization technique is explored for the Solution of phase stability and phase equilibrium. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Liquid-liquid equilibria, Phase equilibrium, Phase stability analysis, Repulsive particle swarm method}, issn = {0378-3812}, doi = {10.1016/j.fluid.2009.04.014}, author = {Rahman, Imran and Das, Anwesh Kr. and Mankar, Raju B. and Kulkarni, B. D.} } @article { ISI:000266088200028, title = {Pilot plant study of recovery of lactic acid from ethyl lactate}, journal = {Organic Process Research \& Development}, volume = {13}, number = {3}, year = {2009}, month = {MAY}, pages = {573-575}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Purified lactic acid is used for production of biodegradable polymer. Esterification with ethanol and subsequent hydrolysis in distillation columns to produce purified lactic acid without catalyst has obvious advantages. In this paper, we present a pilot-plant study of ethyl lactate hydrolysis to produce 3.86 kg/h lactic acid (99.85\% purity) using three distillation columns. Simulation of distillation columns at steady state has been carried out, and the results obtained tally with the experimental results of the pilot plant.

}, issn = {1083-6160}, doi = {10.1021/op800312k}, author = {Barve, Prashant P. and Rahman, Imran and Kulkarni, Bhaskar D.} } @article { ISI:000300467100008, title = {Purification of lactic acid via esterification of lactic acid using a packed column, followed by hydrolysis of methyl lactate using three continuously stirred tank reactors (CSTRs) in series: a continuous pilot plant study}, journal = {Industrial \& Engineering Chemistry Research}, volume = {51}, number = {4}, year = {2012}, month = {FEB}, pages = {1506-1514}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The world market of lactic acid is growing every year, mainly as a solvent and precursor to poly(lactic acid) (PLA). The cost of renewable biomass-derived PLA will have to compete with other synthetic polymers, if it is to grab a significant and sustainable fraction of the market share. It is thus necessary to have efficient and cost-effective technology for the production of pure-grade lactic acid (LA). In this article, a novel cost-effective, eco-friendly continuous process for the production of high-quality lactic acid at pilot plant scale has been demonstrated. The novelty of this process is that, for the first time, we report and use the concept of inverse reactive distillation for the esterification of crude concentrated LA in a continuous countercurrent packed column mode. This allows us to operate the column at higher temperatures, improving the kinetic rate process and leading to shorter columns. This is followed by the hydrolysis of methyl lactate (MLA) in a series of three continuously stirred tank reactors (CSTRs), where LA itself acts as a catalyst. The LA obtained in the pilot plant process shows 99.81\% purity (by weight) on water-free basis and has an optical purity of 99.9\%. The pilot scale experimental results pertaining to the autocatalytic esterification of LA and hydrolysis of MLA have been compared and validated, with respect to simulated results. The innovations reported here can make the process economically viable for commercial use.

}, issn = {0888-5885}, doi = {10.1021/ie200642j}, author = {Kamble, Sanjay P. and Barve, Prashant P. and Joshi, Jyeshtharaj B. and Rahman, Imran and Kulkarni, Bhaskar D.} } @article { ISI:000328153400006, title = {Design of decanter in heterogeneous azeotropic distillation column by minimizing Gibbs free energy}, journal = {Asia-Pacific Journal of Chemical Engineering}, volume = {8}, number = {6}, year = {2013}, month = {NOV}, pages = {843-848}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

In this paper, liquid-liquid equilibrium in decanter of heterogeneous azeotropic distillation is solved by minimizing Gibbs free energy, by using global optimization technique. The azeotropic distillation column is modeled by solving material balance, equilibrium and summation equations, and repulsive particle swarm optimization (RPSO), a stochastic global optimization formalism, is employed to predict stable steady state solution in decanter. To verify the performance of the RPSO algorithm, it is compared with equation solving method for liquid-liquid equilibria by considering two azeotropic systems, namely (1) benzene-ethanol-water and (2) furfural-water. The proposed methodology shows feasibility of the RPSO algorithm in predicting liquid-liquid equilibrium in decanter of heterogeneous azeotropic distillation. (c) 2013 Curtin University of Technology and John Wiley \& Sons, Ltd.

}, keywords = {decanter, Gibbs free energy, heterogeneous azeotropic distillation, liquid-liquid equilibrium, Optimization, repulsive particle swarm optimization method}, issn = {1932-2135}, doi = {10.1002/apj.1728}, author = {Rahman, Imran and Ubaidullah, S. and Das, Anwesh Kr.} } @article { ISI:000312999200020, title = {Optimization of the production of a maltooligosaccharides producing amylase from the alkalophilic streptomyces lonarensis strain NCL 716 using SVR modeling}, journal = {Starch-Starke}, volume = {65}, number = {1-2}, year = {2013}, month = {JAN}, pages = {179-185}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The Streptomyces lonarensis strain NCL 716 hydrolyses starch to produce a mixture of maltotriose (G3) and maltotetraose (G4) along with maltose (G2). The objective of the present work was to determine an optimum cost effective media composition for the production of a-amylase from this strain. The most influential factor was found to be starch while the least influential factor found was peptone by PlackettBurman method. Peptone amount was kept constant throughout the fermentation. Peptone, which is one of the expensive media components was used at a concentration of 1?g/L, which made the optimum media composition cost effective. A support vector regression-based process model was developed for approximating the non-linear relationship between the fermentation operating variables and the a-amylase yield. Multicanonical Jump Walk Annealing, a stochastic optimization technique is used to obtain optimal operating variables to maximize amylase yield. The maximum amylase activity thus obtained was in good agreement with the experimental values at the optimized levels. The optimum media composition obtained by this method was: yeast extract: 4.53?g/L, starch: 20.246?g/L, K2HPO4: 0.0827\%, MgSO4: 0.15\%, peptone: 1?g/L. A maximum enzyme activity of 297?U/mL, which was achieved using the above approaches compares well with the activity of reported amylases producing maltooligosaccharides.

}, keywords = {Alkaline a-amylase, Optimization, Streptomyces, Support vector regression analysis}, issn = {0038-9056}, doi = {10.1002/star.201200094}, author = {Sharma, Trupti K. and Bhadane, Vaibhav A. and Kumar, Lalitha S. and Rele, Meenakshi V. and Bhawar, Gajanan and Rahman, Imran} } @article {44446, title = {Deep learning based data driven soft sensor for bioprocesses}, journal = {Biochemical Engineering Journal}, volume = {136}, year = {2018}, month = {AUG}, pages = {28-39}, type = {Article}, abstract = {

Developing accurate and robust sensors for nonlinear and highly varying systems is a challenge. Deep learning, an advanced technique to learn deep architectures, has become a popular training strategy while dealing with complex problems. In this paper, deep learning has been introduced to develop data driven soft sensors for estimating crucial parameters in two fermentation processes, namely, Streptokinase and Penicillin. Additionally, the performance of the developed soft sensor is compared to an SVR based soft sensor. The results clearly indicate that deep learning is an attractive alternative to traditional techniques for soft sensor modelling as it represents nonlinear systems better, makes full advantage of process data by also incorporating unlabelled data and handles large datasets efficiently. Deep learning proves to be a promising technique for soft sensor modelling in highly data driven complex bioprocesses.

}, doi = {10.1016/j.bej.2018.04.015}, author = {Gopakumar, Vineet and Tiwari, Sarthak and Rahman, Imran} } @article {46039, title = {Ring opening polymerization of lactide: kinetics and modeling}, journal = {Chemical Engineering Communications}, volume = {206}, year = {2019}, month = {SEP }, pages = {1159-1167}, type = {Article}, abstract = {

The ring opening polymerization (ROP) kinetics of L-lactide was studied in bulk at 150, 160, and 180 degrees C using stannous octoate [Sn(Oct)(2)] catalyst and 1-pyrene butanol co-catalyst. The effect of different parameters namely, time and co-catalyst to catalyst ratio was studied on the properties of polylactide. The experimental results showed high conversion of L-lactide. The kinetics of L-lactide ROP follows the co-ordination insertion mechanism. The experimental results obtained were studied to account for the reversible activation, propagation, termination, and validated by modeling using MATLAB. The model developed successfully predicts the monomer conversion and the kinetics of L-lactide ROP.

}, keywords = {1-pyrene butanol, Average molecular weights, GPC, kinetics, L-Lactide, Modeling and simulation, Polymerization temperature, Proton NMR, ROP, Stannous octoate}, issn = {0098-6445}, doi = {10.1080/00986445.2018.1550395}, author = {Metkar, Sangeeta and Sathe, Vivek and Rahman, Imran and Idage, Bhaskar and Idage, Susheela} }