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Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents a proposal for the automation of a batch reactor for the production of addition polymers, in which an exothermic chemical reaction, generated in the polymerization process, takes place. We propose to control the temperature of the product through a split range control strategy with cascade controllers considering the product temperature loop as the primary loop and the jacket temperature loop as the secondary loop. The phenomenological modeling of the reactor was carried out from material and energy balances to obtain the transfer function of the system and estimate the parameters of the controllers. The results obtained in the simulation and control of the process show the good performance of the system working with the process temperature set-point between 92 °C and 96 °C. In addition, a significant improvement in the monomer-polymer conversion of the product is observed in this range. [ABSTRACT FROM AUTHOR]

Copyright of Ingenius, Revista Ciencia y Tecnología is the property of Universidad Politecnica Salesiana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Colombiana de Biotecnología is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Alkaline wastewater is a by-product of many textile industries. A pH adjustment is required by the addition of acidic products. By determining the kinetics of the neutralization reaction between these waters and CO2, the conceived treatment system will be more efficient. Objective: Define the rate law for the reaction between textile wastewater and carbon dioxide in the UB "Desembarco del Granma". Materials and Methods: Residual water from the textile process and CO2 were used. Experiments were carried out in a batch reactor. The integral method of kinetic data analysis and non-parametric hypothesis tests were used. Results and Discussion: The basic pH of the effluent to the mill is due to the use of NaOH in textile processes. Two non-parametric hypothesis tests for the values of the reaction-specific rate constants (k) reflected standard deviations of 0.171 and 0.76 respectively, higher than 0.05, so there are no significant differences between the four groups considered for each temperature. With the non-parametric hypothesis test for k at 50 and 30 °C, the level of significance (0.001) corroborated the dependence of each k with temperature. Conclusions: The specific rate constants for the temperatures of 30°C and 50°C determined are 57.98 and 105.94 L/(mol s) respectively for the neutralization reaction of the textile wastewater with CO2. The reaction is of order 2 presents an activation energy value of 24.5 kJ/mol. [ABSTRACT FROM AUTHOR]

Introduction: Anaerobic digestion of cheese whey is a very attractive and widely used technology, although strategies are needed to counteract the rapid whey acidification, which causes a pH dismiss and subsequent failures. Objective: To evaluate cheese whey anaerobic digestion using anaerobic pig manure sludge as inoculum, as well as the influence of different inoculum-substrate relationships and the reaction kinetics in each case. Materials and Methods: Inoculum and serum characterization was carried out in the UNISS laboratories according to standard methods; 2 L batch reactors were used to determine methane yield at three inoculum-substrate ratios (1:1, 2:1 y 3:1). Results and Discussion: It is possible to degrade this serum with the pig manure inoculum in the first 24-48 hours, although the potential of contained methane is not reached, due to the necessary prior inoculum adaptation and the inhibition implied by the substrate acidity. Reactors with a 3:1 substrate-inoculum ratio showed the highest methane yield (191 LNCH4kgVS-1). Kinetic analysis revealed that the Hill model was the best fit, although the fit of all the experimented models allows predicting the methane yield. Conclusions: This work demonstrates that it is possible to use anaerobic pig manure sludge to start bioreactors that treat cheese whey, and the Hill model can be used to predict methane formation. [ABSTRACT FROM AUTHOR]

Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ingenius, Revista Ciencia y Tecnología is the property of Universidad Politecnica Salesiana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main objective of this study was to analyze the antioxidant capacity (measured with FRAP and ABTS) and the chelating potential of iron over time at different enzyme and substrate conditions. Enzymatic hydrolysis of bovine whey powder was performed in a batch reactor with a capacity of 0.5 L and constant temperature. The most active hydrolysates were separated according to their molecular size at a rate of> 100, 10-100, <10 and <3 KDa to verify the antioxidant capacity contributed by each of them. The data obtained showed that antioxidant activity is higher at lower enzyme concentrations. But, the potential for peptide fractions with the ability to neutralize ABTS+ cations is low at low substrates. The increase in hydrolysis degree favors the antioxidant activity measured by the ABTS method and the chelating activity of hydrolyzed metals. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sorbitol is an important platform molecule with applications in the food, cosmetics and pharmaceutical sectors and with potential in biopolymers. It is obtained in batch reactors through the hydrogenation of glucose, on Ni-Raney catalysts. The leaching of nickel in the reaction media involves additional purification steps and makes the product more expensive. This work evaluates the current and future market of sorbitol, considering its applications. In addition, it collects information on the use of different metals and supports that offer higher selectivity in obtaining sorbitol from glucose or directly from cellulose, from biomass residues. It was verified that the sorbitol market presents an expectation of growth of more than 5 % until 2022. Even though the Ni-Raney catalyst is the most economically competitive, it can be replaced efficiently by the ruthenium supported in different materials. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present work, the parametric sensitivity of the cyclonite production in a batch reactor was assessed. The objective was to establish safe operation conditions for this highly exothermic reaction. The reaction rate law was fitted using experimental data published in the literature. Mass and energy balances were reparametrized. Thus, reaction temperature sensitivity criteria were established as a function of initial reaction and cooling temperatures. Critical reaction conditions were defined using the temperature-sensitivity, temperature-conversion, and the locus of the temperature maxima. A critical heat generation potential (M) equal to 34 was defined together with the following runaway critical conditions: a Semenov number (ψ) equal to 0.684, a heat of reaction parameter (B) equal to 15 and an Arrhenius-type number (γ) of 20. Therefore, temperature-conversion profiles precise a critical relation between the cooling and heat potential (N/M) of 2.5786. [ABSTRACT FROM AUTHOR]

Copyright of Avances en Ciencias e Ingeniería is the property of Avances en Ciencias e Ingenieria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A kinetic model was used to study the reaction rate of hydrolysis of bovine plasma proteins and alcalase 2.4 L, in a batch reactor. The influence of variables, such as the concentration of initial enzyme substrate and the degree of hydrolysis was studied, and kinetic parameters of the rate equation were determined by analyzing its relationship with the work variables. A zero-order kinetic model and enzyme deactivation by substrate was found, as well as the direct relationship between the fraction of enzyme-substrate and the rate of formation of hydrolysis products. [ABSTRACT FROM AUTHOR]