Bio-based succinic acid (SA) obtained by fermentation is considered a major platform molecule for... more Bio-based succinic acid (SA) obtained by fermentation is considered a major platform molecule for the future chemical industry. It can be used as feedstock and intermediate in production of solvents, surfactants, biodegradable polymers, specialty chemicals and commodities. With some organisms, fermentation to produce SA also produces acetic acid (AcAc) and small amounts of pyruvic, lactic, and/or formic acid, making difficult to isolate pure SA crystals. Among proposed alternatives to economically separate and recover these carboxylic acids esterification has proven an attractive alternative. Because esterification is equilibrium limited, the ongoing removal of products during reaction is required to achieve complete reaction. In that sense, reactive distillation (RD) columns can be used not only to overcome equilibrium limitations by removing reaction products, but it also can separate succinic esters from other carboxylic acid esters formed. In this work, a pilot scale reactive di...
Fatty acid butyl esters (FABE) are commercially important chemicals used in a wide range of appli... more Fatty acid butyl esters (FABE) are commercially important chemicals used in a wide range of applications such as lubricants, emulsifiers, detergents, and as biofuel constituents. An alternate approach to direct esterification of fatty acids for producing higher alcohol esters is to first make the fatty acid methyl esters (FAME) via traditional base catalysis and then transesterify FAME with other alcohols using heterogeneous catalysts to produce the desired esters. In previous work, we have characterized kinetics of methyl stearate transesterification with n-butanol using Amberlyst 15; this reaction is slow at 90oC even with a very large excess of butanol. Above 90°C or at high catalyst loadings, ether formation takes place, liberating water which leads to hydrolysis of the esters. Conventional reactive distillation will likely be uneconomical for this reaction system because of the slow reaction rate and temperature limitations. We present here a study that evaluates the potential ...
Reactive distillation is a multifunctional process where chemical reaction and distillation occur... more Reactive distillation is a multifunctional process where chemical reaction and distillation occur simultaneously in a single integrated vessel. The numerous advantages arising from the synergistic interaction of unit operations in a single unit over conventional, sequential operation of a reactor followed by a distillation column include overcoming thermodynamic limitations of chemical reaction, improving selectivity via rapid removal of products from the reaction zone to limit secondary reactions, reacting away azeotropes, utilizing exothermic heat of reaction for vaporization, and avoiding hot spot formation. Organic acid esters, produced by reaction of organic acids and alcohols, can be classified as biorenewable or green chemicals that replace petroleum-based solvents. Succinic acid esters have low toxicity and vapor pressure at the same time exhibit exceptional solvent properties and find commercial applications in solvents and paint strippers. In addition succinate esters are ...
The production of biodiesel from plant triglycerides leads to formation of byproduct glycerol, a ... more The production of biodiesel from plant triglycerides leads to formation of byproduct glycerol, a versatile feedstock in itself for producing chemicals such as propylene glycol and epichlorohydrin. It is well known that glycerol can be converted into cyclic acetals via condensation with aldehydes; for example, 2-methyl-4-hydroxymethyl-1,3-dioxolane and 2-methyl-5-hydroxy-1,3-dioxane are formed via reaction of glycerol with acetaldehyde. These compounds have desirable properties as fuel additives via improving pour point and viscosity of biodiesel, and reducing particulate emissions from fuel combustion. Glycerol acetals can be synthesized directly with aldehydes or by transacetalization with another acetal compound. In this paper, we present results of glycerol acetal synthesis using 1,1-diethoxyethane (DEE). Reaction kinetics and equilibria, along with physical property data such as reactant miscibility, have been studied at different reaction temperatures, reactant molar ratios, an...
Diluted aqueous solutions of organic acids are generated in different fermentation processes as t... more Diluted aqueous solutions of organic acids are generated in different fermentation processes as the valuable product or byproduct. Many of those fermentation systems yield a mixture of products depending on the intended metabolic pathways and conditions within the bioreactor. The recovery and purification of individual species from fermentor effluents can be costly, contributing more than 50% of the overall production cost in some cases. Several alternatives have been proposed to overcome this problem. Among others, reactive distillation (RD) has proved success in the recovery of different acids through esterification with a variety of alcohols. Taking this into account, this work is focused on the process to recover and esterify mixed acids produced by fermentation. Initially it is presented a new and simple method to recover carboxylic acids from diluted aqueous solutions prior esterification reaction. After recovery, and based upon a previous work involving lactate and citrate es...
Rapid Process Scale-Up Through Innovative Design Methodologies John Prindle1, Richard Doctor1, As... more Rapid Process Scale-Up Through Innovative Design Methodologies John Prindle1, Richard Doctor1, Aspi Kolah2, Carl Lira2, Dennis Miller2, and C.B. Panchal1 1E3tec Service, LLC, Clarksville, MD 21029, USA 2Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, USA Abstract Scale-up of chemical processes is an expensive, time-consuming component on the path to commercialization. While many new lab-scale technologies have been created to improve specific aspects of scale-up, additional improvements can be achieved by making detailed performance prediction tools an integral part of the process development. This integration should be seamless and is particularly necessary when scaling up a multiphase reaction system or systems involving process intensification. Questions involving commercial process robustness and sensitivity to operation/feed parameters are compounded when process units, such as distillation and reactors, are int...
Significant advances have been made by industry and academic research organizations to establish ... more Significant advances have been made by industry and academic research organizations to establish the commercial advantages of Reactive Distillation (RD). It is an effective but challenging technique for energy-efficient synthesis of major commodity chemicals with added advantages of process simplification. However, the following key technical barriers hinder wider application of RD: a) effective ways to improve contact between the catalyst and reacting phases; b) effective thermal management approaches to maintain an optimal global temperature profile that would also influence global distribution of reactants and the localized temperature distribution in the catalyst bed; and c) a fundamental rate-based model to elucidate the effect improvements in thermal management and catalyst contact might have on the localized reactive multi-phase flows. This presentation will focus on the potential benefits of implementing several different thermal management approaches to a reactive distillat...
Organic acids, typically produced by fermentation of carbohydrate feedstocks, constitute an impor... more Organic acids, typically produced by fermentation of carbohydrate feedstocks, constitute an important class of biorenewable platform chemicals that can be further converted to useful products. Tri-ethyl citrate (TEC), produced from citric acid and ethanol, is currently gaining of attention as a non-toxic, biocompatible plasticizer that can be used in place of petroleum-based phthalate compounds. Phthalates have potential carcinogeneity and overall health concerns to the extent that they have been banned in Europe from use in children’s toys and human contact applications. At present, the potential of TEC is limited by the lack of large-scale, energy efficient and economic production. Esters are advantageously produced using reactive distillation, where simultaneous reaction and separation take place in the same process unit. However, the hardware design of standard reactive distillation columns exhibits challenges for slow chemical reactions such as tri-ethyl citrate formation, beca...
Cyclohexanol is a very important bulk chemical feedstock for the polymer industry, primarily as a... more Cyclohexanol is a very important bulk chemical feedstock for the polymer industry, primarily as a precursor to nylon but also a plasticizer component and solvent. The conventional process for cyclohexanol synthesis is either cyclohexane oxidation, hydrogenation of phenol, or the direct hydration of cyclohexene. The direct hydration route, which is the simplest in principle, suffers from limited solubilities of the cyclohexene-water pair, thus requiring large amounts of catalyst and high residence times. An alternative to the direct hydration of cyclohexene is the indirect hydration process where acetic acid is used as the reactive entrainer. In the first step of this process cyclohexene from the inlet mixture of cyclohexene and cyclohexane reacts with acetic acid to form cyclohexyl acetate, which is hydrolyzed with water to cyclohexanol in the second step. In this paper we present the reaction of cyclohexene from a mixture of cyclohexene and cyclohexane with acetic acid to form cycl...
Cyclohexanol is an important bulk chemical feedstock for the polymer industry, primarily as a pre... more Cyclohexanol is an important bulk chemical feedstock for the polymer industry, primarily as a precursor to nylon, but also as a plasticizer component and solvent. The conventional process for cyclohexanol synthesis is either cyclohexane partial oxidation, hydrogenation of phenol, or the direct hydration of cyclohexene. The direct hydration route of cyclohexene to form cyclohexanol, which is the simplest in principle, suffers from limited solubilities of the cyclohexene-water pair, thus requiring large amounts of catalyst and high residence times with intense mixing, and process chilling. An alternative to the direct hydration of cyclohexene is the two-stage indirect hydration process employing heat-integrated reactive distillation. The justification for a two-stage operation employing (1) esterification and (2) hydrolyzation builds upon the earlier studies by Sundmacher, et al., [1] Here acetic acid is used as the reactive entrainer in a reactive distillation operation. In the first...
... Navinchandra Asthana, Aspi Kolah, Dung T. Vu, Carl T. Lira, and Dennis J. Miller*. Department... more ... Navinchandra Asthana, Aspi Kolah, Dung T. Vu, Carl T. Lira, and Dennis J. Miller*. Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, USA. Org. Process Res. Dev. ...
Description/Abstract The following is the final report of the three year research program to conv... more Description/Abstract The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the ...
Bio-based succinic acid (SA) obtained by fermentation is considered a major platform molecule for... more Bio-based succinic acid (SA) obtained by fermentation is considered a major platform molecule for the future chemical industry. It can be used as feedstock and intermediate in production of solvents, surfactants, biodegradable polymers, specialty chemicals and commodities. With some organisms, fermentation to produce SA also produces acetic acid (AcAc) and small amounts of pyruvic, lactic, and/or formic acid, making difficult to isolate pure SA crystals. Among proposed alternatives to economically separate and recover these carboxylic acids esterification has proven an attractive alternative. Because esterification is equilibrium limited, the ongoing removal of products during reaction is required to achieve complete reaction. In that sense, reactive distillation (RD) columns can be used not only to overcome equilibrium limitations by removing reaction products, but it also can separate succinic esters from other carboxylic acid esters formed. In this work, a pilot scale reactive di...
Fatty acid butyl esters (FABE) are commercially important chemicals used in a wide range of appli... more Fatty acid butyl esters (FABE) are commercially important chemicals used in a wide range of applications such as lubricants, emulsifiers, detergents, and as biofuel constituents. An alternate approach to direct esterification of fatty acids for producing higher alcohol esters is to first make the fatty acid methyl esters (FAME) via traditional base catalysis and then transesterify FAME with other alcohols using heterogeneous catalysts to produce the desired esters. In previous work, we have characterized kinetics of methyl stearate transesterification with n-butanol using Amberlyst 15; this reaction is slow at 90oC even with a very large excess of butanol. Above 90°C or at high catalyst loadings, ether formation takes place, liberating water which leads to hydrolysis of the esters. Conventional reactive distillation will likely be uneconomical for this reaction system because of the slow reaction rate and temperature limitations. We present here a study that evaluates the potential ...
Reactive distillation is a multifunctional process where chemical reaction and distillation occur... more Reactive distillation is a multifunctional process where chemical reaction and distillation occur simultaneously in a single integrated vessel. The numerous advantages arising from the synergistic interaction of unit operations in a single unit over conventional, sequential operation of a reactor followed by a distillation column include overcoming thermodynamic limitations of chemical reaction, improving selectivity via rapid removal of products from the reaction zone to limit secondary reactions, reacting away azeotropes, utilizing exothermic heat of reaction for vaporization, and avoiding hot spot formation. Organic acid esters, produced by reaction of organic acids and alcohols, can be classified as biorenewable or green chemicals that replace petroleum-based solvents. Succinic acid esters have low toxicity and vapor pressure at the same time exhibit exceptional solvent properties and find commercial applications in solvents and paint strippers. In addition succinate esters are ...
The production of biodiesel from plant triglycerides leads to formation of byproduct glycerol, a ... more The production of biodiesel from plant triglycerides leads to formation of byproduct glycerol, a versatile feedstock in itself for producing chemicals such as propylene glycol and epichlorohydrin. It is well known that glycerol can be converted into cyclic acetals via condensation with aldehydes; for example, 2-methyl-4-hydroxymethyl-1,3-dioxolane and 2-methyl-5-hydroxy-1,3-dioxane are formed via reaction of glycerol with acetaldehyde. These compounds have desirable properties as fuel additives via improving pour point and viscosity of biodiesel, and reducing particulate emissions from fuel combustion. Glycerol acetals can be synthesized directly with aldehydes or by transacetalization with another acetal compound. In this paper, we present results of glycerol acetal synthesis using 1,1-diethoxyethane (DEE). Reaction kinetics and equilibria, along with physical property data such as reactant miscibility, have been studied at different reaction temperatures, reactant molar ratios, an...
Diluted aqueous solutions of organic acids are generated in different fermentation processes as t... more Diluted aqueous solutions of organic acids are generated in different fermentation processes as the valuable product or byproduct. Many of those fermentation systems yield a mixture of products depending on the intended metabolic pathways and conditions within the bioreactor. The recovery and purification of individual species from fermentor effluents can be costly, contributing more than 50% of the overall production cost in some cases. Several alternatives have been proposed to overcome this problem. Among others, reactive distillation (RD) has proved success in the recovery of different acids through esterification with a variety of alcohols. Taking this into account, this work is focused on the process to recover and esterify mixed acids produced by fermentation. Initially it is presented a new and simple method to recover carboxylic acids from diluted aqueous solutions prior esterification reaction. After recovery, and based upon a previous work involving lactate and citrate es...
Rapid Process Scale-Up Through Innovative Design Methodologies John Prindle1, Richard Doctor1, As... more Rapid Process Scale-Up Through Innovative Design Methodologies John Prindle1, Richard Doctor1, Aspi Kolah2, Carl Lira2, Dennis Miller2, and C.B. Panchal1 1E3tec Service, LLC, Clarksville, MD 21029, USA 2Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, USA Abstract Scale-up of chemical processes is an expensive, time-consuming component on the path to commercialization. While many new lab-scale technologies have been created to improve specific aspects of scale-up, additional improvements can be achieved by making detailed performance prediction tools an integral part of the process development. This integration should be seamless and is particularly necessary when scaling up a multiphase reaction system or systems involving process intensification. Questions involving commercial process robustness and sensitivity to operation/feed parameters are compounded when process units, such as distillation and reactors, are int...
Significant advances have been made by industry and academic research organizations to establish ... more Significant advances have been made by industry and academic research organizations to establish the commercial advantages of Reactive Distillation (RD). It is an effective but challenging technique for energy-efficient synthesis of major commodity chemicals with added advantages of process simplification. However, the following key technical barriers hinder wider application of RD: a) effective ways to improve contact between the catalyst and reacting phases; b) effective thermal management approaches to maintain an optimal global temperature profile that would also influence global distribution of reactants and the localized temperature distribution in the catalyst bed; and c) a fundamental rate-based model to elucidate the effect improvements in thermal management and catalyst contact might have on the localized reactive multi-phase flows. This presentation will focus on the potential benefits of implementing several different thermal management approaches to a reactive distillat...
Organic acids, typically produced by fermentation of carbohydrate feedstocks, constitute an impor... more Organic acids, typically produced by fermentation of carbohydrate feedstocks, constitute an important class of biorenewable platform chemicals that can be further converted to useful products. Tri-ethyl citrate (TEC), produced from citric acid and ethanol, is currently gaining of attention as a non-toxic, biocompatible plasticizer that can be used in place of petroleum-based phthalate compounds. Phthalates have potential carcinogeneity and overall health concerns to the extent that they have been banned in Europe from use in children’s toys and human contact applications. At present, the potential of TEC is limited by the lack of large-scale, energy efficient and economic production. Esters are advantageously produced using reactive distillation, where simultaneous reaction and separation take place in the same process unit. However, the hardware design of standard reactive distillation columns exhibits challenges for slow chemical reactions such as tri-ethyl citrate formation, beca...
Cyclohexanol is a very important bulk chemical feedstock for the polymer industry, primarily as a... more Cyclohexanol is a very important bulk chemical feedstock for the polymer industry, primarily as a precursor to nylon but also a plasticizer component and solvent. The conventional process for cyclohexanol synthesis is either cyclohexane oxidation, hydrogenation of phenol, or the direct hydration of cyclohexene. The direct hydration route, which is the simplest in principle, suffers from limited solubilities of the cyclohexene-water pair, thus requiring large amounts of catalyst and high residence times. An alternative to the direct hydration of cyclohexene is the indirect hydration process where acetic acid is used as the reactive entrainer. In the first step of this process cyclohexene from the inlet mixture of cyclohexene and cyclohexane reacts with acetic acid to form cyclohexyl acetate, which is hydrolyzed with water to cyclohexanol in the second step. In this paper we present the reaction of cyclohexene from a mixture of cyclohexene and cyclohexane with acetic acid to form cycl...
Cyclohexanol is an important bulk chemical feedstock for the polymer industry, primarily as a pre... more Cyclohexanol is an important bulk chemical feedstock for the polymer industry, primarily as a precursor to nylon, but also as a plasticizer component and solvent. The conventional process for cyclohexanol synthesis is either cyclohexane partial oxidation, hydrogenation of phenol, or the direct hydration of cyclohexene. The direct hydration route of cyclohexene to form cyclohexanol, which is the simplest in principle, suffers from limited solubilities of the cyclohexene-water pair, thus requiring large amounts of catalyst and high residence times with intense mixing, and process chilling. An alternative to the direct hydration of cyclohexene is the two-stage indirect hydration process employing heat-integrated reactive distillation. The justification for a two-stage operation employing (1) esterification and (2) hydrolyzation builds upon the earlier studies by Sundmacher, et al., [1] Here acetic acid is used as the reactive entrainer in a reactive distillation operation. In the first...
... Navinchandra Asthana, Aspi Kolah, Dung T. Vu, Carl T. Lira, and Dennis J. Miller*. Department... more ... Navinchandra Asthana, Aspi Kolah, Dung T. Vu, Carl T. Lira, and Dennis J. Miller*. Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, USA. Org. Process Res. Dev. ...
Description/Abstract The following is the final report of the three year research program to conv... more Description/Abstract The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the ...
Uploads
Papers by Aspi Kolah