Pervaporation Desulfurization of a Thiophene/n-Octane Mixture Using PPO Membranes Modified with Hybrid Star-Shaped Macromolecules

Abstract

The presence of sulfur-containing impurities in petroleum naphtha causes a decrease in the cost and quality of fuels, a reduction in the service life of car engines, and an increase in the amount of harmful emissions into the atmosphere. Pervaporation is an alternative cost-effective fuel desulfurization method. In this study, hybrid membranes based on poly(2,6-dimethyl-1,4-phenylene oxide) and a star-shaped modifier for the pervaporation separation of a thiophene/n-octane model mixture is developed. Hybrid star-shaped macromolecules comprising six polystyrene arms and six poly(2-vinylpyridine)-block-poly(tert-butyl methacrylate) diblock copolymer arms grafted onto a common fullerene C 60 central core are used as the modifier. Membrane structure is analyzed by scanning electron microscopy and atomic force microscopy. Thermal properties are studied by differential scanning calorimetry. The separation properties of the membranes are determined at low thiophene concentrations (up to 0.08 wt %). It is shown that the introduction of a starshaped modifier leads to an increase in the extraction efficiency of sulfur-containing impurities from octane, which is the main fuel component.

Strongly Selective Polymer Membranes Modified with Heteroarm Stars for the Ethylene Glycol Dehydration by Pervaporation

“…Hybrid PPO membranes modified with star macromolecules composed of a C 60 core and six polystyrene (PS) arms and six poly-2-vinylpyridine (P2VP) arms have provided enhanced selectivity in dehydration of acetic acid [26] and separation of the quaternary mixture (n-propanol/acetic acid/propyl acetate/water) [27]. It has been reported [27][28][29][30][31] that PPO membranes modified with star macromolecules exhibited enhanced pervaporation performance, presumably due to the presence of polymer arms with a different chemical nature (nonpolar and polar) in a modifier. The PS arms are fully compatible with the PPO matrix and a phase separation does not occur up to the temperatures of their thermal destruction [32].…”

Novel Polyester Amide Membranes Containing Biquinoline Units and Complex with Cu(I): Synthesis, Characterization, and Approbation for n-Heptane Isolation from Organic Mixtures

“…Thus, the study of the transport parameters of the membranes in pervaporation of the thiophene/n-heptane mixture showed that the PEA membrane is more selective for the isolation of thiophene impurities, although the polymer-metal complex exhibits a higher total flux. The membranes under study demonstrate moderate separation properties over those of the literature data [15][16][17][18]21]; however, they are very thermally and mechanically strong and show long-term operational stability.…”

“…The main sulfur-containing impurity in hydrocarbons extracted from the Earth is thiophene; therefore, in this work, a model gasoline consisting of a binary mixture of thiophene and n-heptane is considered. As membrane material for removal of thiophene from gasoline, different polymers such as polyphenylene oxide, polyphosphazene, polyvinylidene fluoride, polyhedral oligomeric silsesquioxane POSS, polysulfone, and polyether-block-amide Pebax, have been used [15][16][17][18][19][20][21][22].…”

A Review of Recent Developments of Pervaporation Membranes for Ethylene Glycol Purification

“…Hyder and Chen provided another method for PVA modification that consisted of mixing a polymer solution with different amounts of chitosan (CS) (25,50,70,75, and 80 wt.%) [30]. It is known that successful mixing can improve separation characteristics, since the mobility of macromolecular chains changes in the process of intermolecular interactions between polymers.…”

“…Introducing star-shaped macromolecules as fillers can be a promising way to improve the separation capacity of pervaporation membranes [ 73 , 74 , 75 ]. Hybrid membranes based on poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) modified with heteroarm stars (HAS) ( Figure 3 ) were developed by Rostovtseva et al [ 76 ].…”