Vol. 13, no.2, 2021


Salting-in–salting-out effect of potassium salts on the binary liquid water + n-butoxyethanol system with a closed delamination region

Maksim P. Smotrov, Dmitry G. Cherkasov, Konstantin K. Il'in

N.G. Chernyshevsky Saratov National Research State University, https://sgu.ru/, Institute of Chemistry
Saratov 410012, Russian Federation
E-mail: maxim-smotrov@yandex.ru, dgcherkasov@mail.ru, ilinkk@sgu.ru

Received 11 May, 2021, peer-reviewed 14 May, 2021, accepted 18 May, 2021

Abstract: The work is devoted to the comparative characteristics of the salting-in –salting-out effect of potassium formate, nitrate and perchlorate on the binary liquid water + n-butoxyethanol system with a closed delamination region in a temperature range of 10–150°C. The introduction of potassium formate or potassium nitrate into the mixtures of the critical composition of the binary water + n-butoxyethanol system leads to a decrease in the LCST (lower critical solution temperature) and an increase in the UCST (upper critical solution temperature) of this system, while the addition of potassium perchlorate leads to an increase in the LCST and a decrease in the UCST. For three ternary systems potassium salt + water + n-butoxyethanol, the distribution coefficients of n-butoxyethanol between the aqueous and organic phases of the monotectic state were calculated for several temperatures. It has been found that the distribution coefficient increases with temperature in each system. It has been established that potassium formate and potassium nitrate have a salting-out effect, the former having a particularly strong one. Potassium perchlorate at low concentrations and relatively low temperatures is characterized by a salting-in effect, which turns into a weak salting-out effect at higher temperatures. The results obtained can be used to develop practical recommendations for carrying out selective extraction of organic solvents and extractive crystallization of salts.

Keywords: phase equilibria, critical phenomena, binary system, ternary system, salting-in, salting-out

UDC 544.344.016+536.44

RENSIT, 2021, 13(2):177-186. DOI: 10.17725/rensit.2021.13.177.

Full-text electronic version of this article - web site http://en.rensit.ru/vypuski/article/386/13(2)177-186e.pdf