imran rahman - Academia.edu (original) (raw)
Papers by imran rahman
Chemical Engineering & Technology, Jul 1, 2007
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Ramaswamy/Separation and Purification Technologies in Biorefineries, 2013
ABSTRACT Recently lactic acid (LA) and its polymer, polylactic acid (PLA), have attracted the att... more ABSTRACT Recently lactic acid (LA) and its polymer, polylactic acid (PLA), have attracted the attention of world researchers due to their versatile commercial applications. Whether LA can be used to its full potential largely depends on whether it can be produced in a cost-effective manner with high purity and optical activity. The major technology barrier in the costeffective production of high-purity lactic acid is its downstream separation and purification. This chapter presents a case study where different techniques such as electrodialysis, adsorption, solvent extraction, membrane separation and reactive distillation were analyzed for separation of lactic acid from fermentation froth. Among them, reactive distillation was found to be promising at an industrial scale. Autocatalytic reactive distillation of lactic acid with methanol using a packed bed column followed by hydrolysis of methyl lactate with lactic acid catalyst, using three CSTRs in series, has been reported for purification of lactic acid.
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Industrial & Engineering Chemistry Research, 2011
ABSTRACT The world market of lactic acid is growing every year, mainly as a solvent and precursor... more 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.
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Chemical Engineering & Technology, 2007
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Organic Process Research & Development, 2009
Purified lactic acid is used for production of biodegradable polymer. Esterification with ethanol... more 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 ...
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Fluid Phase Equilibria, 2009
In literature, there are two broad approaches for phase equilibrium calculations: Gibbs' fre... more In literature, there are two broad approaches for phase equilibrium calculations: Gibbs' free energy minimization and solving non-linear equations for stationary points [1]. According to McDonald and Floudas [2], due to complexity of UNIFAC, modified Wilson, or ASOG activity ...
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Chemical Engineering Research & Design, 2007
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Chemical Engineering Research & Design, 2001
ABSTRACT
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Chemical Product and Process Modeling, 2008
∗Chemical Engineering & Process Development Division, National Chemical Laboratory, Pune-4110... more ∗Chemical Engineering & Process Development Division, National Chemical Laboratory, Pune-411008, India, r.imran@ncl.res.in Chemical Engineering Department, National Institute of Technology (NIT), Warangal - 506 004, India, arsalanchem@gmail.com Chemical ...
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Separation and Purification Technology, 2006
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Chemical Engineering & Technology, Jul 1, 2007
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Ramaswamy/Separation and Purification Technologies in Biorefineries, 2013
ABSTRACT Recently lactic acid (LA) and its polymer, polylactic acid (PLA), have attracted the att... more ABSTRACT Recently lactic acid (LA) and its polymer, polylactic acid (PLA), have attracted the attention of world researchers due to their versatile commercial applications. Whether LA can be used to its full potential largely depends on whether it can be produced in a cost-effective manner with high purity and optical activity. The major technology barrier in the costeffective production of high-purity lactic acid is its downstream separation and purification. This chapter presents a case study where different techniques such as electrodialysis, adsorption, solvent extraction, membrane separation and reactive distillation were analyzed for separation of lactic acid from fermentation froth. Among them, reactive distillation was found to be promising at an industrial scale. Autocatalytic reactive distillation of lactic acid with methanol using a packed bed column followed by hydrolysis of methyl lactate with lactic acid catalyst, using three CSTRs in series, has been reported for purification of lactic acid.
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Industrial & Engineering Chemistry Research, 2011
ABSTRACT The world market of lactic acid is growing every year, mainly as a solvent and precursor... more 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.
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Chemical Engineering & Technology, 2007
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Organic Process Research & Development, 2009
Purified lactic acid is used for production of biodegradable polymer. Esterification with ethanol... more 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 ...
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Fluid Phase Equilibria, 2009
In literature, there are two broad approaches for phase equilibrium calculations: Gibbs' fre... more In literature, there are two broad approaches for phase equilibrium calculations: Gibbs' free energy minimization and solving non-linear equations for stationary points [1]. According to McDonald and Floudas [2], due to complexity of UNIFAC, modified Wilson, or ASOG activity ...
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Chemical Engineering Research & Design, 2007
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Chemical Engineering Research & Design, 2001
ABSTRACT
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Chemical Product and Process Modeling, 2008
∗Chemical Engineering & Process Development Division, National Chemical Laboratory, Pune-4110... more ∗Chemical Engineering & Process Development Division, National Chemical Laboratory, Pune-411008, India, r.imran@ncl.res.in Chemical Engineering Department, National Institute of Technology (NIT), Warangal - 506 004, India, arsalanchem@gmail.com Chemical ...
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Separation and Purification Technology, 2006
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