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Öğe Production and Recovery of Pyruvic Acid: Recent Advances(Springer India, 2017) Pal D.; Keshav A.; Mazumdar B.; Kumar A.; Uslu H.Pyruvic acid is an important keto-carboxylic acid and can be manufactured by both chemical synthesis and biotechnological routes. In the present paper an overview of recent developments and challenges in various existing technique for the production and recovery of pyruvic acid from fermentation broth or from waste streams has been presented. The main obstacle in biotechnological production of pyruvic acid is development of suitable microorganism which can provide high yield and selectivity. On the other hand, technical limitation in recovery of pyruvic acid from fermentation broth is that, it could not be separated as other carboxylic acid in the form of salts by addition of alkali. Besides, pyruvic acid cannot be crystallized. Commercial separation by distillation is very expensive because pyruvic acid decomposes at higher temperature. It is also chemically reactive due to its peculiar molecular structure and has tendency to polymerize. Thus, at high concentration the various type of reaction leads to lower yield of the product, and hence, conventional methods are not favorable. Alternate separation technologies viable to both synthetic and biological routes are the current research areas. Latest techniques such as reactive extraction is new to the field of recovery of pyruvic acid. Recent development and future prospects in downstream processing of biochemically produced pyruvic acids has been discussed in this review article. © 2017, The Institution of Engineers (India).Öğe Reactive separation of p-nitro phenol (PNP) from aqueous solution using tri-n-butyl phosphate: equilibrium and COSMO-RS studies(Taylor and Francis Inc., 2019) Kumari A.; Gaur A.; Uslu H.; Kumar S.The present study is aimed to optimized diluent type, tri-n-butyl phosphate (TBP) composition and temperature for the reactive extraction of p-nitro phenol (PNP) in two different PNP concentration ranges [(0.00036–0.00646) kmol·m?3 and (0.00646–0.01437) kmol·m?3] as found in industrial effluents. 1-Octanol is investigated as the best diluent with TBP based on COSMO-RS theory. Equilibrium study based on mass action law is performed to find the insights of extraction mechanisms, equilibrium constant (K = 295.12 k·mol?1) and stoichiometry (m:n = 1:1) as also confirmed by FTIR. Thermodynamic parameters, enthalpy (?H°), and entropy (?S°) are determined 27.51 K J mol?1 and ?50.21 J mol?1 K?1, respectively. © 2018, © 2018 Taylor & Francis Group, LLC.Öğe Separation of Levulinic Acid Using Polymeric Resin, Amberlite IRA-67(American Chemical Society, 2019) Uslu H.; Datta D.; Santos D.; Öztürk M.The adsorptive separation of levulinic acid (LA) from its aqueous solution was studied by using a commercial adsorbent and weakly basic anion exchange resin, Amberlite IRA-67 (IRA-67). The data were generated for equilibrium and kinetic studies, and to analyze the performance of IRA-67 on the removal efficiency. The equilibrium study was performed to see the effect of adsorbent quantity (0.25-1.5 g) and initial LA concentrations (2-4 g·L-1) at three different temperatures (298, 308, and 318 K). To determine the kinetics of adsorption process, concentration profile was achieved up to a time of 90 min at 298 K. It was observed that both the intake capacity (32-64 mg·g-1) and removal efficiency (6.75-72.5%) of IRA-67 were increased with an increase in the quantity of adsorbent (0.25-1.5 g) at 298 K. From the kinetics of adsorption, 50 min was considered as an equilibrium time. Different isotherm and kinetic models were used to determine the equilibrium and kinetic parameters of LA adsorption process. From the temperature study (298, 308, and 318 K), the thermodynamic properties were also estimated at three different LA concentrations. © 2019 American Chemical Society.
