Pérez, Alan

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Alan
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Alan Pérez

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2016 - 201972020 - 20222
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Autor:in: Fontalvo, Javier ×

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Gerade angezeigt 1 - 9 von 9
  • Vorschaubild nicht verfügbar
    Publikation
    Liquid extraction with immobilized liquids for product recovery from fermentation broths
    (Elsevier, 2022) Pérez, Alan; Gössi, Angelo; Riedl, Wolfgang; Schuur, Boelo; Fontalvo, Javier; Thatoi, Hrudayanath; Mohapatra, Sonali; Das, Swagat Kumar [in: Innovations in fermentation and phytopharmaceutical technologies]
    Nowadays, many fermentation chemicals are produced at an industrial scale. Numerous technological improvements have been developed and implemented to achieve high quality and quantity of fermentation products. However, several drawbacks in fermentation processes still limit their application at an industrial level. In situ product removal (ISPR) is a potential alternative to overcome the conventional drawbacks of the fermentative processes, increasing the fermentation's productivity and reducing the separation steps for recovery and purification. Currently, liquid extraction has emerged as a promising separation technology for ISPR, with immobilized liquids such as membrane-assisted extraction and microchannel liquid membrane, due to the high mass transfer rates, scalability, easy integration, and efficiency. This chapter will discuss these technologies regarding their integration into fermentative processes.
    04A - Beitrag Sammelband
  • Vorschaubild nicht verfügbar
    Publikation
    Liquid–liquid equilibria for trioctylamine/1-dodecanol/citric acid/water system at 303.1 and 308.1 K: Experimental data and prediction
    (American Chemical Society, 2020) Murcia-Montalvo, Laura; Pérez, Alan; Fontalvo, Javier [in: Journal of Chemical & Engineering Data]
    The present work experimentally tests the liquid–liquid equilibria (LLE) of aqueous citric acid (CA) solutions with trioctylamine (TOA) in 1-dodecanol at 303.2 and 308.2 K. A predictive model has been developed based on the experimental data. This model considers the physical dissolution of CA and complexation with TOA. At low CA concentrations, the stoichiometric ratio of acid/amine is (1:1). However, the acid/amine ratios of (1:1), (1:2), and (2:1) are present at high CA concentrations. The equilibrium constants for the different complexes were determined and compared to previous studies, which employed other organic solvents. The equilibrium constants obtained in this study are comparatively higher, making 1-dodecanol an attractive solvation medium. Also, the literature presents LLE experiments with contact times from minutes to hours. Because of this lack of consensus, this work displays experimental evidence to suggest contact and settling times required for experimental evaluation of the equilibria in liquid–liquid systems based on the standard deviation.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Modeling of a liquid membrane in Taylor flow integrated with lactic acid fermentation
    (Elsevier, 10/2019) Pérez, Alan; Van der Bruggen, Bart; Fontalvo, Javier [in: Chemical Engineering and Processing: Process Intensification]
    The application of a liquid membrane in Taylor flow (LMTF) is a promising method that can be integrated with other separation or reactive processes in view of process intensification. In this work, a model for a hybrid LMTF – fermentation system was developed for lactic acid production using batch fermentation and LMTF experimental data. The hybrid model is compared to experimental data of the hybrid system. Through a sensitivity analysis of the main variables of the LMTF an optimum value of the overall volumetric mass transfer coefficient (0.0122 1/s) was achieved for lactic acid removal. This was further used for modeling the hybrid system. The fermentation time of the hybrid system is reduced by 7 h, the productivity and biomass concentration is increased by 2.578 g/(L·h) and 2.7016 g/L, respectively, as compared with a batch fermentation. In addition, the effect of the number of channels of the LMTF is modeled and its impact on productivity, fermentation time, and final biomass concentration is analyzed. It was concluded that lactic acid removal through the LMTF from the fermentation broth is an alternative to control the pH within fermenter.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Integration of a liquid membrane in Taylor flow regime with a fermentation by Lactobacillus casei ATCC 393 for in-situ lactic acid removal
    (Elsevier, 06/2019) Pérez, Alan; Rodríguez-Barona, Sneyder; Fontalvo, Javier [in: Chemical Engineering and Processing: Process Intensification]
    A new type of liquid membranes called liquid membrane in Taylor flow was integrated to a lactic acid fermentation, using Lactobacillus casei ATCC 393, for lactic acid removal during fermentation. The performance in terms of lactic acid production of the hybrid batch system is compared to a conventional batch fermentation. Lactic acid removal rate increases proportionally with the LA concentration within the fermenter. The lactic acid, the biomass production and the LA productivity in the hybrid system increased by 41.8, 12 and 26.6%, respectively, as compared to the conventional batch fermentation. However, toxicity effects reduce LA to glucose yield in 15.9% as compared to conventional fermentation. Liquid membranes in Taylor flow results promising for enhancing batch and continuous fermentation processes by a hybrid system.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild
    Publikation
    A new concept of liquid membranes in Taylor flow. Performance for lactic acid removal
    (Elsevier, 05/2019) Pérez, Alan; Fontalvo, Javier [in: Chemical Engineering and Processing: Process Intensification]
    A liquid membrane in Taylor flow regime is a novel alternative kind of contact in three-phase flow for liquid membranes that preserves the advantages of conventional emulsion liquid membranes while overcomes the stability problems of emulsion systems. As a proof of concept, this work presents experimental results of a liquid membrane in Taylor flow for lactic acid removal. Several operating conditions, such as injection times, delay times and flow of the membrane phase were tested for a channel length and inner diameter of 348.8 cm and 2.5 mm, respectively. The lactic acid removal is mainly affected by the driving force of lactic acid concentrations between donor droplets and the membrane interface, and the space-time. Thus, the lactic acid removal process through the liquid membrane in Taylor flow is enhanced at low injection times and high droplet velocity considering that enough space-time is provided. This technology results promising as an alternative to conventional liquid membranes and the intensification of chemical and fermentative processes.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Liquid–liquid equilibria of lactic acid/water solutions in tri-iso-octylamine/dodecane/1-dodecanol at 306.1, 310.1, and 316.1 K. Experimental data and prediction
    (American Chemical Society, 2019) Pérez, Alan; Rodríguez-Barona, Sneyder; Fontalvo, Javier [in: Journal of Chemical & Engineering Data]
    The liquid–liquid equilibria of systems that involves lactic acid in the aqueous phase and tri-iso-octylamine with diluents as dodecane and 1-dodecanol (active or/and inert) were measured experimentally at three temperatures (306.15, 310.15, and 316.15 K). A previous liquid–liquid equilibrium model that is based on Nernst’s distribution law and mass action law equilibrium equations was extended and generalized for stoichiometric ratios (amine/acid) 1:n. The effect of the diluents and the tertiary amine on the liquid–liquid equilibrium is shown and quantified in terms of the predicted values of the distribution coefficient, chemical equilibrium constants, and temperature. The lactic acid concentration in equilibrium for the organic phase decreases as follows: water/LA/TiOA/1-dodecanol system > water/LA/TiOA/dodecane/1-dodecanol > system water/LA/TiOA/dodecane system.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Liquid–liquid equilibrium and molecular toxicity of active and inert diluents of the organic mixture tri-iso-octylamine/dodecanol/dodecane as a potential liquid membrane for lactic acid removal
    (American Chemical Society, 2019) Pérez, Alan; Gómez, Verónica M.; Rodríguez-Barona, Sneyder; Fontalvo, Javier [in: Journal of Chemical & Engineering Data]
    Lactic acid can be in situ removed from a fermentation broth through reactive liquid extraction or a liquid membrane to enhance the fermentation process. The organic mixture tri-iso-octylamine (TiOA)/dodecanol/dodecane at 10 vol % of the amine is a potential organic mixture for lactic acid removal. Liquid–liquid equilibria with lactic acid aqueous solutions and molecular toxicity on the bacteria Lactobacillus casei ATCC 393 were measured with several dodecanol proportions in dodecane (0 to 90 vol %) and 10 vol % TiOA as potential solvents or membrane phases for LA removal from a fermentation broth. Effects of the organic phase on the bacteria as cell growth, biomass production, glucose consumption, productivity, and product to biomass yield are analyzed. Dodecanol increases the lactic acid chemical equilibrium constant for the liquid–liquid equilibria, while increasing the molecular toxicity on the bacteria. However, for dodecanol concentrations from 30 to 40 vol % the value of the chemical equilibrium constant is high enough for lactic acid distribution between the phases and its toxicity is low enough on the bacteria, making a proper range of dodecanol concentrations for lactic acid removal. Also, the distribution coefficient and the chemical equilibrium constant are fitted as a function of the dodecanol concentration in the organic mixture.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Study of overall mass transfer coefficients in a liquid membrane in Taylor flow regime: Calculation and correlation
    (Elsevier, 12/2018) Pérez, Alan; Van der Bruggen, Bart; Fontalvo, Javier [in: Chemical Engineering and Processing: Process Intensification]
    The use of a liquid membrane in Taylor flow regime is a recent technology, which extends and generalizes the definition of a membrane. It has been developed and tested for lactic acid removal. A challenge in understanding the technology is that the values of the overall volumetric mass transfer coefficients are not known, and it is unclear how they are related with the operational conditions. In this work, the overall volumetric mass transfer for the liquid membrane in Taylor flow was calculated from experimental results and three empirical models, two of which are from literature and one was developed in this work based on dimensional analysis. From combination of experimental results and the developed models the main variables (operational conditions) of the liquid membrane in Taylor flow that have a strong influence on the overall volumetric mass transfer coefficients (in the donor and in the membrane phase) were defined. The relative velocity results as the variable that has the largest influence on the performance of this new liquid membrane technology.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Liquid–Liquid equilibria for trioctylamine/1-dodecanol/lactic acid/water system at 306.1, 310.1 and 316.1 K: Experimental Data and Prediction
    (American Chemical Society, 2016) Pérez, Alan; Rodríguez-Barona, Sneyder; Fontalvo, Javier [in: Journal of Chemical & Engineering Data]
    Liquid–liquid equilibria of aqueous solutions of lactic acid with trioctylamine diluted in 1-dodecanol was measured experimentally at three temperatures (306.1, 310.1, and 316.1 ± 0.1 K). During the transfer process, lactic acid reacts with trioctylamine to produce an amine–lactate complex. Two models were proposed to predict the liquid–liquid equilibria. The first model considered the equilibrium constant of chemical reaction and the distribution coefficient. Those parameters have been determined by fitting the experimental data. The distribution coefficients have also been experimentally measured. It was found that as temperature increases, the distribution coefficient increases and equilibrium constant decreases. The second proposed model involved the non-random two liquid activity model. Energies of binary interaction and the equilibrium constant of chemical reaction were fitted to experimental data. The equilibrium constant and partition coefficients show the same trends as the first model; however, the first model shows a better prediction as compared to the second model of the liquid–liquid equilibrium data. These two models are especially suitable at low lactic acid concentrations in the aqueous phase where the experimental standard deviation is low.
    01A - Beitrag in wissenschaftlicher Zeitschrift