Production Of Butyl Acetate Research Articles

Dynamic controlled atmosphere monitored by respiratory quotient as a new method to store pears: Effect on the volatile compounds profile and general quality

Pears (Pyrus communis) are climacteric fruit that require storage under appropriate conditions to extend availability and delay ripening. This study evaluated the production of volatile organic compounds (VOCs) and the physicochemical quality of ‘Santa Maria’ and ‘Rocha’ pears after storage in a controlled atmosphere (CA) or dynamic controlled atmosphere (DCA), monitored by respiratory quotient (RQ). The pears, harvested from an orchard in São Joaquim (Santa Catarina State), were stored at − 0.5 °C in CA (2.0 kPa O2) and DCA with RQ levels of 1.1, 1.2, 1.3, and 1.4, all under 1.0 kPa CO2. ‘Santa Maria’ pears were stored for four months, and ‘Rocha’ pears for six months, followed by seven days at 20 °C before quality analysis. Storage of ‘Santa Maria’ pears in CA resulted in fruit with a more yellow skin color, lower flesh firmness, and higher ethylene production, while ‘Rocha’ pears in CA retained higher flesh firmness and produced less ethylene at 4 and 7 days at 20 °C compared to DCA conditions. Storage conditions did not significantly affect soluble solids and acidity. In ‘Rocha’ pears, DCA, regardless of RQ, suppressed the production of butyl acetate, hexyl acetate, pentyl acetate, methyl acetate, and propyl acetate, while in ‘Santa Maria’ pears, esters such as butyl acetate and hexyl acetate were less affected. In conclusion, no significant differences were found between the DCA-RQ levels evaluated in this research in maintaining physicochemical quality and VOCs production. However, DCA suppressed VOCs production in both ‘Santa Maria’ and ‘Rocha’ pears compared with CA storage.

Catalytic performance of pyridinium dihydrogen phosphate ionic liquid for butyl acetate production: theoretical insights and reaction kinetic studies

Catalytic performance of pyridinium dihydrogen phosphate ionic liquid for butyl acetate production: theoretical insights and reaction kinetic studies

Novel Process for Butyl Acetate Production via Membrane Reactor: A Comparative Study with the Conventional and Reactive Distillation Processes

Butyl acetate (BuAc) is widely used as a solvent in many applications, mainly in the food and pharmaceutical industries. The conventional process for BuAc production is both capital and energy intensive. The purification process involves the separation of BuAc from the azeotropic mixture of water and n-butanol, which is difficult to accomplish using a simple distillation unit. In this study, a membrane reactor (MR) for BuAc production via the esterification of n-butanol was investigated. The MR using the Amberlyst-15 catalyst was modeled and validated with previously reported experimental data, and a good agreement was achieved. The ultimate conversion of n-butanol using the MR was 92.0%, compared to 69.8% for the conventional reactor. This study is the first to propose an intensified MR-based process for butyl acetate production. The MR-based process was developed and rigorously simulated using Aspen Plus for an annual plant capacity of 92,500 metric tons of BuAc. The MR-based process is environmentally friendly regarding CO2 emissions, with a reduction of 80% compared to the conventional process. The economic analysis of the MR-based process shows a payback period of 2.7 years and a return on investment (ROI) of 23.1%. The MR-based process for BuAc production is a promising technology that provides similar key benefits as compared to the reactive distillation (RD) process.

Controlling selectivity of modular microbial biosynthesis of butyryl-CoA-derived designer esters

Short-chain esters have broad utility as flavors, fragrances, solvents, and biofuels. Controlling selectivity of ester microbial biosynthesis has been an outstanding metabolic engineering problem. In this study, we enabled the de novo fermentative microbial biosynthesis of butyryl-CoA-derived designer esters (e.g., butyl acetate, ethyl butyrate, butyl butyrate) in Escherichia coli with controllable selectivity. Using the modular design principles, we generated the butyryl-CoA-derived ester pathways as exchangeable production modules compatible with an engineered chassis cell for anaerobic production of designer esters. We designed these modules derived from an acyl-CoA submodule (e.g., acetyl-CoA, butyryl-CoA), an alcohol submodule (e.g., ethanol, butanol), a cofactor regeneration submodule (e.g., NADH), and an alcohol acetyltransferase (AAT) submodule (e.g., ATF1, SAAT) for rapid module construction and optimization by manipulating replication (e.g., plasmid copy number), transcription (e.g., promoters), translation (e.g., codon optimization), pathway enzymes, and pathway induction conditions. To further enhance production of designer esters with high selectivity, we systematically screened various strategies of protein solubilization using protein fusion tags and chaperones to improve the soluble expression of multiple pathway enzymes. Finally, our engineered ester-producing strains could achieve 19-fold increase in butyl acetate production (0.64 g/L, 96% selectivity), 6-fold increase in ethyl butyrate production (0.41 g/L, 86% selectivity), and 13-fold increase in butyl butyrate production (0.45 g/L, 54% selectivity) as compared to the initial strains. Overall, this study presented a generalizable framework to engineer modular microbial platforms for anaerobic production of butyryl-CoA-derived designer esters from renewable feedstocks.

Comprehensive evaluation for the one-pot biosynthesis of butyl acetate by using microbial mono- and co-cultures

BackgroundButyl acetate has shown wide applications in food, cosmetics, medicine, and biofuel sectors. These short-chain fatty acid esters can be produced by either chemical or biological synthetic process with corresponding alcohols and acids. Currently, biosynthesis of short chain fatty acid esters, such as butyl butyrate, through microbial fermentation systems has been achieved; however, few studies regarding biosynthesis of butyl acetate were reported.ResultsIn this study, three proof-of-principle strategies for the one-pot butyl acetate production from glucose through microbial fermentation were designed and evaluated. (1) 7.3 g/L of butyl acetate was synthesized by butanol-producing Clostridium acetobutylicum NJ4 with the supplementation of exogenous acetic acid; (2) With the addition of butanol, 5.76 g/L of butyl acetate can be synthesized by acetate-producing Actinobacillus succinogenes130z (ΔpflA); (3) Microbial co-culture of C. acetobutylicum NJ4 and A. succinogenes130z (ΔpflA) can directly produce 2.2 g/L of butyl acetate from glucose by using microbial co-culture system with the elimination of precursors. Through the further immobilization of A. succinogenes130z (ΔpflA), butyl acetate production was improved to 2.86 g/L.ConclusionDifferent microbial mono- and co-culture systems for butyl acetate biosynthesis were successfully constructed. These strategies may be extended to the biosynthesis of a wide range of esters, especially to some longer chain ones.

Enhanced production of butyl acetate via methanol-extracting transesterification membrane reactors using organosilica membrane: Experiment and modeling

Experimentation and numeric calculation were focused on n-butyl acetate (BA) production from Methyl acetate (MA) and n-butanol (BuOH) via Membrane reactor to extract methanol (MeOH) through 1,2-bis(triethoxysilyl)acetylene(BTESA)-derived organosilica membranes. A batch reactor (BR) model was formulated using Damköhler number (Da) and Permeation number (θ) similarly to plug flow reactor. Simulation on the effect of Da, θ, permeance ratio of MeOH (αi) and MA/BuOH feed molar ratio (δ) showed that a α > 20 and a θ > 10 are required to achieve a high BA yield. BTESA membranes showed high performance for MeOH removal from the mixtures with various types of organic solvents such as various esters, alcohols, Toluene, and ketone. Two types of BTESA membranes: high-flux (M−1) and high-selectivity (M−2), which showed MeOH flux of 4.2 kg/(m2 h) and 2.6 kg/(m2 h), and separation factor of 3100 and 9200, respectively, for MeOH/BA mixtures (MeOH 10 wt%, 50°C), were used for the transesterification membrane reactor. Batch-type membrane reactor performances were evaluated experimentally using M−1 and M−2 membranes. At MA/BuOH feed molar ratio, δ , of 2, extraction of MeOH increased the BA yield reached as high as 95.4%, which was higher than that of equilibrium (60%). Experimental results agreed with numeric calculations without fitting parameters.

Economic, Thermodynamic, and Environmental Analysis and Comparison of the Synthesis Process of Butyl Acetate

The traditional production of butyl acetate (BA) has the problems of low equilibrium conversion rate and high energy consumption of product separation and purification. In this work, the production...

Metabolic and Process Engineering of Clostridium beijerinckii for Butyl Acetate Production in One Step.

n-Butyl acetate is an important food additive commonly produced via concentrated sulfuric acid catalysis or immobilized lipase catalysis of butanol and acetic acid. Compared with chemical methods, an enzymatic approach is more environmentally friendly; however, it incurs a higher cost due to lipase production. In vivo biosynthesis via metabolic engineering offers an alternative to produce n-butyl acetate. This alternative combines substrate production (butanol and acetyl-coenzyme A (acetyl-CoA)), alcohol acyltransferase expression, and esterification reaction in one reactor. The alcohol acyltransferase gene ATF1 from Saccharomyces cerevisiae was introduced into Clostridium beijerinckii NCIMB 8052, enabling it to directly produce n-butyl acetate from glucose without lipase addition. Extractants were compared and adapted to realize glucose fermentation with in situ n-butyl acetate extraction. Finally, 5.57 g/L of butyl acetate was produced from 38.2 g/L of glucose within 48 h, which is 665-fold higher than that reported previously. This demonstrated the potential of such a metabolic approach to produce n-butyl acetate from biomass.

Propyl-SO3H functionalized graphene oxide as multipurpose solid acid catalyst for biodiesel synthesis and acid-catalyzed esterification and acetalization reactions

A graphene based acid catalyst, GO-PrSO3H, was prepared through a simple two-step process. Surface modification with (3-mercaptopropyl) trimethoxysilane followed by oxidation of sulfide groups led to the production of sulfonic acid sites on graphene oxide nanosheets. The results of various physicochemical techniques approved the synthesis of desired catalyst. The amount of acid sites was measured via the acid-base treatment with triethylamine which exhibited 1.07 mmol/g H+ in the catalyst structure. Two kinds of acid-catalyzed reactions i.e. esterification and acetalization were adopted to evaluate the catalytic performance of prepared catalyst. More than 90% conversion was achieved for butyl acetate production in acetic acid esterification with n-butanol. Moreover, methyl oleate as one of the main components of biodiesel was produced with good yield over the prepared catalyst via oleic acid esterification with methanol. The 1H NMR technique was also conducted to characterize and determine the amount of produced methyl oleate. Finally, the benzaldehyde acetalization with ethylene glycol was performed which high conversion (92%) was obtained at 3 h. The catalyst reusability for both esterification and acetalization reactions demonstrated the catalyst stability after five reaction cycles.

Robust Trajectory Tracking in a Reactive Batch Distillation Process using Multirate Nonlinear Internal Model Control

Operating a reactive batch distillation (RBD) process in an optimal manner is of paramount importance for improving product quality and profitability in the face of changing market conditions. However, implementation of an open loop optimal control policy may lead to significant reduction in yield and amount of desired product produced when unmeasured disturbances occur during operation. In this work, an observer error feedback-based multirate nonlinear internal model control (NIMC) scheme is developed for optimal trajectory tracking in the face of unmeasured disturbances. In particular, mismatch in the initial conditions and process parameter variations that can occur during RBD operation are considered. To reduce the time required for online computations, a recently proposed reduced order RBD model [Reddy et al. Compt. Chem. Eng., 2017, 106, 40−56] is used for the controller synthesis. Because the thermodynamic model associated with the RBD process has discontinuities, a multirate version of unscented Kalman filter (UKF) has been developed on the basis of the reduced order model for solving the state estimation problem associated with the proposed NIMC formulation. The efficacy of the proposed approach has been demonstrated by simulating an optimal trajectory tracking problem in the RBD process involving production of butyl acetate. The proposed multirate NIMC formulation is found to be computationally efficient and work reasonably well when tested on the RBD process for solving the set point tracking problem in the presence of unmeasured disturbances. In particular, it is advantageous to operate the RBD process using the proposed UKF-NIMC scheme when the system is subjected to unmeasured disturbances.

Improvement of the butyl acetate process through heat integration: A sustainability-based assessment

The heat integration of a conventional and a reactive distillation technologies for butyl acetate production is studied in this work. Different configurations were evaluated and compared to the original designs in terms of their sustainable performances. The comparison was carried out through the Eco-efficiency Comparison Index method by determining six ecological indicators (raw materials consumption, fuel consumption, energy consumption, CO2 emissions, water consumption and wastewater generation), five economic indicators (specific raw materials cost, specific energy cost, specific water cost, liquid waste cost fraction and yield factor) and three safety indicators (safety hazard fire/explosion, chemical exposure index and chronic toxicity factor). The heat integration proved to be a convenient strategy since it significantly improved the conventional and reactive distillation processes’ eco-efficiencies. While the reactive distillation technology has a 53% higher environmental performance than the conventional route, the former’s integrated arrangement increases its eco-efficiency up to 62% when compared to the latter. Finally, we propose new intensified flowsheets for both the conventional and reactive distillation schemes, being the latter approximately 49% more sustainable than the former.

Dynamics and control of entrainer enhanced reactive distillation using an extraneous entrainer for the production of butyl acetate

This paper introduces the dynamics and control of entrainer-enhanced reactive distillation(ERD) for the efficient production of n-butyl acetate via esterification reaction of butanol and acetic acid. It was recently reported that using an extraneous instead of the internal entrainer (butyl acetate) could considerably improve the process efficiency (Cho et al., 2014). In the ERD system, different multiplicities were found to appear depending on whether the azeotrope that the entrainer forms with water is binary or ternary. In the case of binary azeotrope formation, the extraneous entrainer only takes the role of entrainer if the liquid level of the organic phase in the decanter is controlled. However, in the case of ternary azeotrope formation, both the extraneous entrainer and butyl acetate can take the role of entrainer. Keeping a proper inventory of the extraneous entrainer in the column was crucial for ensuring that the system was at a high conversion steady state, leading to a high butyl acetate yield. This is mainly because the presence of too much extraneous entrainer in the reactive distillation column results in a drop in the reaction yield. We propose two different control schemes depending on the type of azeotrope that the extraneous entrainer forms with the reaction mixture. The proposed control schemes were demonstrated to be effective in maintaining a high reaction yield and product purity.

A hybrid reactive distillation process with high selectivity pervaporation for butyl acetate production via transesterification

A hybrid reactive distillation system with high selectivity pervaporation was examined to produce butyl acetate and methanol via transesterification of methyl acetate with butanol. High selectivity pervaporation was combined with reactive distillation to eliminate a hitherto required column for the separation of a methanol and methyl acetate azeotrope. The polyamide-6 membrane was used for this purpose because of its high selectivity for methanol while also allowing sufficient permeate flux. The high purity methyl acetate recovered in the retentate stream leads to high conversion in the reactive distillation column, which enhances the energy savings (up to 71%) of this process. The feasibility of the proposed hybrid processes and several alternative designs were evaluated by rigorous simulation and optimization using the Aspen Plus software package. The effects of several designs and operating variables were also investigated for the proposed design. The high potential of the hybrid reactive distillation and pervaporation system for butyl acetate production is very promising; it may not only reduce the total annual costs relative to conventional systems but may also provide an attractive strategy to address problems associated with methanol and methyl acetate azeotropes in the effluent generated in the polyvinyl alcohol industry.

Multi-objective optimization of a reactive batch distillation process using reduced order model

Reactive batch distillation (RBD) processes are highly nonlinear in nature and use of first principles model into the optimization problem demands high computational time. Therefore, a reduced order model for RBD process is proposed which is based on selection of states of prime importance, identification of input state variables, definition of reference trajectories for nominal case, and definition of additional variable transformation to facilitate adaptation of the model to variations in operating conditions. Further, the work focuses on development of a multi-objective optimization formulation for arriving at an optimal operation policy for RBD, and a modified version of Non-dominated sorting Genetic algorithm (NSGA-II) is developed for its solution. The proposed approach is evaluated by application to a simulation case study for production of butyl acetate. The optimization results obtained using the reduced order model are comparable to those obtained with first principles model, while requiring only 1/20th of the time.

VOLATILE COMPOUNDS IN GOLDEN DELICIOUS APPLE FRUIT (Malus domestica) DURING COLD STORAGE

Biosynthesis of volatile compounds (VC), as well as activity of related enzymes (lipoxygenase LOX, alcohol acyltransferase AAT, and alcohol dehydrogenase ADH), and fatty acids (palmitic, stearic, oleic, linoleic and linolenic acids) were assessed in Golden Delicious fruit apples (Malus domestica Borkh.) during 1 ºC storage at different atmosphere conditions. Three atmosphere conditions were used: 21 % O2 and > 1 % CO2 (Regular Atmosphere, RA), 3 % CO2 and 2 % O2 (Controlled Atmosphere, CA), and CA, with 7 d under RA conditions (CA + RA), to evaluate the effect of shorts periods under air storage. CA conditions inhibited the production of butyl acetate and hexyl acetate esters, and increased hexanol concentration. Production of the branched ester 2-methyl butyl acetate did not decrease under CA conditions. As a result of 7 d under RA, butyl acetate and hexyl acetate in CA + RA increased, mainly after one month of storage. Storage under CA conditions inhibited LOX and AAT activity at some stages whereas ADH activity increased during CA storage. LOX activity showed high correlation with production of aldehydes (r2 = 0.85) and cis-2-hexenal (r2 = 0.94), during storage of apples under CA conditions. Good correlation was found between AAT activity and total esters and butyl acetate content under CA storage of apples (r2 = 0.92 and r2 = 0.93, respectively). While most fatty acids increased in concentration during RA and CA storage, linolenic acid content decreased. No correlation between volatile compounds content and fatty acid production was found.

Design of Model Predictive Control for Butyl Acetate Production in Reactive Distillation

An efficient operation of the reactive distillation is challenging due to its complex dynamics resulting from the coupling of reaction and separation tasks into a single unit. Conventional control schemes cannot always handle with highly nonlinear and multivariable systems. Therefore, this study considers the implementation of a model predictive control (MPC) to the reactive distillation column in which the esterification of butanol and acetic acid to produce butyl acetate is chosen as a case study. The control objective is to maintain the butyl acetate product at a desired purity without the accumulation of unreacted reactants in the reactive zone of the reactive distillation. Two alternative control structures of MPC controller are proposed. The first one is based on the two-point temperature control (CS1), whereas the second one involves the one-point temperature control and the direct control of the acetic acid composition (CS2) within the reactive distillation. It is found that the MPC with CS2 structure shows a better performance under disturbance rejection and set-point tracking case studies; faster and smoother responses with less oscillation are observed.

Entrainer-Enhanced Reactive Distillation for the Production of Butyl Acetate

A new reactive distillation (RD) process using a mass separation agent (extraneous entrainer) for the efficient production of butyl acetate from butanol and acetic acid via an esterification reaction was proposed. Until now, butyl acetate, a product of the esterification reaction, has been used as an internal entrainer in the production of butyl acetate. It has also been accepted that a configuration consisting of a prereactor followed by a reactive distillation column is most suitable for the production of butyl acetate. The use of an internal entrainer may shift the reaction equilibrium to be favorable to the reverse reaction in the reactive section, limiting the reaction yield. However, an extraneous entrainer, such as cyclohexane, can resolve the problem. It can be used to break the water–alcohol azeotrope and remove water more efficiently from the reactive section. In this study, we proposed a single reactive distillation configuration without a prereactor and the use of an extraneous entrainer (cycl...

Separation of methanol–n-butyl acetate mixtures by pervaporation: Potential of 10 commercial membranes

The transesterification reaction to produce methanol and butyl acetate has great interest in the chemical industry. The separation of these two compounds from the reaction media increases the productivity, thus, a hybrid configuration composed of reaction–pervaporation is of interest. In this work, 10 commercial specialty membranes (PolyAn and Sulzer Pervap membranes) have been studied in a pervaporation setup at three temperatures (30, 40 and 50°C) and a feed concentration ranging between 20 and 80mol% methanol/butyl acetate in order to determine their performance in terms of permeance, selectivity and the McCabe–Thiele separation diagram. From the results, it can be observed that most of the membranes are butyl acetate selective, with selectivities up to 307 and permeances of butyl acetate up to about 80,000 GPU. In general, an increase in temperature decreases the permeance of butyl acetate through the PolyAn membranes and it has a dramatic effect on the Pervap 1201 membrane since the selectivity to butyl acetate decays from 300 at 30°C to around 0.2 at 50°C. The Pervap 2255–50 membrane presents an increase of selectivity as the temperature increases. On this basis the potential of developing a pervaporation membrane reactor for production of butyl acetate by transesterification is assessed.

Effects of physicochemical properties of ionic liquids on butyl acetate synthesis using Candida antarctica lipase B

Butyl acetate synthesis in imidazolium ring-based ionic liquids (ILs) containing trifluoromethanesulfonate, [TfO]− using Candida antarctica lipase B was demonstrated. Among the ILs tested, the highest butyl acetate production and its initial rate was achieved in [Bmim][TfO]. Compared with tert-butanol, which has been the conventional solvent for transesterification reactions, the initial reaction and conversion rate were approximately 1.4 and 1.1 times, respectively, higher. Some physicochemical parameters, such as viscosity, hydrophobicity, and partial charge of ILs were examined to find the relations which influence reaction rates. Although only weak correlations between each parameter and enzyme activity were found, it shed a light on understanding the generalization complexity of ILs for enzyme reaction.

Optimal Design of Staged Three-Phase Reactive Distillation Columns Using Nonequilibrium and Orthogonal Collocation Models

Reactive distillation with potential liquid-phase split and subsequent formation of a third phase is a highly complex process system nevertheless quite common in the production of useful solvents and biofuels through esterification. The optimal design of such process systems requires the development and solution of reliable and accurate process models that lead to a computationally demanding mathematical problem. In this work, a nonequilibrium (NEQ) model coupled with the orthogonal collocation on finite elements (OCFE) technique is developed for the simulation and optimal design of three-phase reactive distillation systems. The resulting NEQ/OCFE model combines the predictive accuracy of the NEQ model as well as the model reduction and approximation capabilities of the OCFE formulation. Therefore, an accurate but compact in size and thus easier to solve model that accounts for all the physical phenomena, the interactions among the multiple phases, and the occurring chemical reactions becomes available. The NEQ/OCFE model is enriched with an accurate prediction procedure for the identification and tracking of the phase transition boundaries (point of transition for a single liquid phase to two liquid-phase regimes and vice versa) inside the column for varying operating conditions. The model is validated using experimental results and utilized in the optimal design and the dynamic simulation of a staged reactive distillation column for the production of butyl acetate via the esterification reaction of butanol with acetic acid. The optimal column configuration defined by the number of stages in each column section, the feed strategy (single feed or multiple feed points), the location of the feed stages, and the operating conditions are calculated through a rigorous design optimization procedure for tight production purity specifications. At optimal conditions the specific column appears to have both two- and three-phase regions that are separated by the feed stage.