Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Polish Journal of Chemical Technology

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Thermodynamics

Sortuj według:

Ogranicz wyniki do:

Thermodynamic analysis on disproportionation process of cyclohexylamine to dicyclohexylamine

Valeš Roman, Dvořák Bohumír, Krupka Jiří

Polish Journal of Chemical Technology

2021

Vol. 23, nr 3

43--48

This work deals with a study of the effect of temperature on the cyclohexylamine disproportionation to dicyclohexy-lamine, conjointly with the thermodynamic analysis of this process. The laboratory experiments were carried out in a glass tubular continuous-flow reactor in a gaseous phase at the reaction temperature 433–463 K over a nickel catalyst. The results show, that the temperature has a trifing effect on equilibrium conversion of cyclohexylamine. However, temperature affects the formation of hydrocarbons, benzene and cyclohexane, and dehydrogenation products of dicyclohexylamine, i.e. N-cyclohexylidenecyclohexanamine and N-phenylcyclohexylamine. The latter one is the dominant product of dicyclohexylamine dehydrogenation. The disproportionation of cyclohexylamine has slightly exothermic character. At the experimental reaction temperature range, the cyclohexylamine disproportionation is spontaneous reaction and other reactions of this process are non-spontaneous.

Adsorption of congo red from aqueous solutions by porous soybean curd xerogels

Zhang Z., Li Y., Du Q., Li Q.

Polish Journal of Chemical Technology

2018

Vol. 20, nr 3

95--102

Soybean curd is a very popular food containing high-quality protein, polyunsaturated fats, vitamins, minerals and other nutrients. This study aims to prepare porous soybean curd xerogels via a vacuum freeze drying method and uses them as adsorbents to remove congo red from aqueous solutions. The morphology and functional groups of the soybean curd xerogels were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. The adsorption properties of congo red onto the soybean curd xerogels were carried out through investigating the influencing experimental parameters such as the drying method, solution pH, adsorbent dose, contact time and temperature. The results showed that the adsorption isotherm data were fitted well to the Freundlich isotherm. Adsorption kinetics of congo red onto the soybean curd followed the pseudo-second-order kinetic model. The thermodynamic parameters, such as ΔG°, ΔH° and ΔS°, were also determined.