Choline-Based Deep Eutectic Solvent In The Liquid-Liquid Extraction Of Xylene From N-octane

The separation of alkanes and arenes is an important technology, and play a significant role in the field of petrochemical industry. Xylene and octane are always separated to satisfied a variety of requirement for their closing boiling points. They are easily to form azeotrope, however, A great of problems are waiting to be solved in traditional separation techniques.In 2003, a solvent which is a mixture of quaternary ammonium salt and amide with a certain proportion was found by Abbott el.,which possesses good physical and chemical properties, such non-poisonous easy to be biodegrade, and we call it deep eutectic solvent(DES). For atom utilization in the synthetics of it reached for 100%, we treat it as a kind of novel green solvents.In this work, three choline-based deep eutectic solvent are selected as the solvent in the extraction of xylene from octane. They are [ChCl][Malonic], [ChCl][Glycerol], [ChCl][Urea].At first, three kinds of choline-based DES was synthetize, after which determination of water content and purity analysis carried out through the method of NMR and Karl Fischer Moisture Titrator. And then, the liquid-liquid equilibrium (LLE) data for the ternary mixtures of {n-octane(1)+ o-xylene(2)+DES(3)}、{n-octane(1)+m-xylene(2)+DES(3)}、{n-octane(1) +p-xylene(2)+DES(3)} were experimentally determined at atmospheric pressure and T= 298.15 K. The consistency of tie-line data was ascertained by applying the Othmer-Tobias equations. From the experiment data、distribution coefficient and selective, we can found that:Overall performance of [ChCl][Glycerol] in separating xylene with octane is good, while performance of [ChCl][Urea] is excellent with a high mole fraction of xyplene. At last, The NRTL(non-random two liquid) model was used to correlate and predict the LLE data of system, the modes parameters were fitted. Besides this, the extraction simulation was made by Aspen Plus at atmospheric pressure and T=298.15 K for [ChCl][Glycerol],The results show that choline-based DES can be confirmed as a potential alternative solvent for the separation of xylene from octane.