Hossein Abolghasemi; Hadis Khakbaz
Abstract
1,3-Butadiene, BD is produced from C4-cut by extractive distillation. The separation of 1,3-Butadiene from C4-cut is not possible through the conventional distillation processes, because several mixtures have consisted of close boiling points constituents and make azeotrope. The BASF extraction distillation ...
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1,3-Butadiene, BD is produced from C4-cut by extractive distillation. The separation of 1,3-Butadiene from C4-cut is not possible through the conventional distillation processes, because several mixtures have consisted of close boiling points constituents and make azeotrope. The BASF extraction distillation process in BD unit of Jam and Amirkabir Petrochemical Company improves the relative volatilities of components by addition of a high boiling point solvent (namely N- methylpyrrolidone, 8.3%wt H2O). With respect to high mass ratio of total solvent to feed, the solvent has significant role in separation. In this study, extractive distillation system was simulated with the HYSYS3.1 software to investigate the effect of the temperature and as well as that of feed entry stage of the solvent on the separation. It was found that; the reduction of solvent temperature had no considerable effect on products’ specifications, but rather, it could minimize the solvent rate.
Sohrabali Ghorbanian; Hossein Abolghasemi; Mohammad Ali Mousavian; Sa'eed Reza Radpour
Sohrabali Ghorbanian; Hossein Abolghasemi; Seyyed Mohammad Ali Mousavian
Abstract
In this research paper, an experimental breakthrough curve for citric acid in an adsorption recovery process was determined by an ion-exchange resin in 20, 35, 55 °C. Also, a mathematical model for breakthrough curve was presented. Among ion exchange resins that have been experienced, many weak and ...
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In this research paper, an experimental breakthrough curve for citric acid in an adsorption recovery process was determined by an ion-exchange resin in 20, 35, 55 °C. Also, a mathematical model for breakthrough curve was presented. Among ion exchange resins that have been experienced, many weak and strong basic anionic resins are available such as, IRA-92, IRA-93, IRA-420 and IRA-458 and all of them were experienced in this work. It was shown that IRI-93 has good performance and compatibility. To obtain concentration of citric acid in the outlet stream from the resin glass column, spectrophotometer UV-VIS, Cary 1E/ Cary 3E from Varian Company was used. The results indicated weak basic kinds are suitable for organic acids recovery, especially for citric acid. Also, the results showed that Amberlite IRA-93 is one of the best resins for recovery of citric acid. In the transient state adsorption, the breakthrough isothermal adsorption curve was obtained in different temperatures. Generally, although an increase in temperature causes an increase in diffusion coefficient of particles, the saturation capacity of resin (or the effective adsorption of acid in the bed) decreases. Several models in different forms, such as fractional, polynomial and exponential, were developed and with analyzing these models a new mathematical model in the form of and modified form of were developed for prediction of the breakthrough curve with low error. Also, if the model is to be used for the break through curve between start and terminal rapture points, the situation of fitting is in the best condition and error less than 1% could be achieved. In this way, least square method in Eviews software was applied. With using these models, the variation of similar breakthrough curves could be fitted, appropriately.
