Abstract
Hydrocarbon separation relies on energy-intensive distillation. Membrane technology can offer an energy-efficient alternative but requires selective differentiation of crude oil molecules with rapid liquid transport. We synthesized multiblock oligomer amines, which comprised a central amine segment with two hydrophobic oligomer blocks, and used them to fabricate hydrophobic polyamide nanofilms by interfacial polymerization from self-assembled vesicles. These polyamide nanofilms provide transport of hydrophobic liquids more than 100 times faster than that of conventional hydrophilic counterparts. In the fractionation of light crude oil, manipulation of the film thickness down to ~10 nanometers achieves permeance one order of magnitude higher than that of current state-of-the-art hydrophobic membranes while retaining comparable size- and class-based separation. This high permeance can markedly reduce plant footprint, which expands the potential for using membranes made of ultrathin nanofilms in crude oil fractionation.
Filtering hydrocarbons
Thin-film composite membranes synthesized through interfacial polymerization on a porous supports are used for water filtration on an industrial scale. Li
et al
. incorporated hydrophobic vesicles into the synthesis process to act as carriers to bring pure hydrocarbon or fluorinated hydrocarbon molecules into the thin top layer of the polymer film. This approach boosts the permeance for hydrophobic solvents, enabling the membranes to combine high permeance and high rejection rates when dealing with mixtures of organic molecules, and the authors were able to demonstrate the separation of realistic crude oil mixtures. —MSL
Polymer-composite membranes can separate components of crude oil.