A solvent-free post-treatment process known as vapor phase infiltration (VPI) is used to engineer the organic solvent reverse osmosis (OSRO) performance of polymer of intrinsic microporosity 1 (PIM-1) membranes via infiltration of trimethylaluminum (TMA) metal-organic vapor. The infiltration of inorganic aluminum constituents hybridizes the pure polymer PIM-1 into an organic-inorganic material (AlOxHy/PIM-1) with enhanced chemical stability. A homogenous distribution of inorganic loading in PIM-1 is achieved due to the reaction-limited infiltration mechanism, and the OSRO performance is enhanced as a result. OSRO separations of ethanol/isooctane mixtures using these membranes are shown to be capable of breaking the azeotropic composition with a separation factor for ethanol over isooctane greater than 5 and an ethanol permeance of 0.1 Lm–2h–1bar–1. Thus, these organic-inorganic hybrid membranes created via VPI show promise as an alternative method for separating azeotropic liquid mixtures.
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Ultrasound-Mediated Nonequilibrium Separation of Ethanol-Water Solutions, Including Avoidance of the Azeotropic Bottleneck
Separation of liquid mixtures, frequently by distillation, is ubiquitous in the chemical and process industries (CPI). Distillation accounts for ~95% of the energy used in liquid separations, ~25–40% of overall energy used in CPI, and ~3% of global energy consumption.1-2 The low efficiency of distillation is largely due to two issues. First, there are large irreversible losses due to heat transfer.3 Second, a significant fraction of energy used in liquid separations is used to separate azeotropic mixtures in azeotrope-forming systems (e.g., ethanol/water). While a number of conventional distillation technologies4-5 (e.g., pressure-swing, extractive distillation, and azeotropic distillation6) and new separation approaches5 (e.g., dividing-wall columns, membranes, molecular sieves, and bio-absorbance) have been developed for azeotropic systems, these approaches largely rely on thermal separation via phase equilibrium or involve large capital and/or operational costs.
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- Award ID(s):
- 2113915
- PAR ID:
- 10523604
- Editor(s):
- AIChE
- Publisher / Repository:
- 2018 AIChE Annual Meeting. AIChE
- Date Published:
- Format(s):
- Medium: X
- Location:
- 2018 AIChE Annual Meeting. AIChE, 2018
- Sponsoring Org:
- National Science Foundation
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