membrane-based solvent dehydration to facilitate
TRANSCRIPT
U.S. Environmental Protection AgencyOffice of Research and Development
Membrane-based Solvent Dehydration to Facilitate Industrial Solvent
Reuse and Remanufacturing
Leland Vane1, Franklin Alvarez1, Vasudevan Namboodiri1, and Michael Abar2
1U.S. EPA, National Risk Management Research Laboratory, 26 W. Martin Luther King Dr., Cincinnati, Ohio2NCBA, SEE Program, 26 W. Martin Luther King Dr., Cincinnati, Ohio 45268 USA
l [email protected] l 513-569-7799
high
Motivation Solvents Targeted
Project Approach
References/Acknowledgements/Disclaimers
The life cycle of industrial solvents presents sources of emissions that potentially impact human health and the environment. The impact of using solvents can be reduced by recovering and reusing the solvents.
The Remanufacturing Exclusion in EPA’s Definition of Solid Waste rule1 intended, in part, to promote reuse of 18 organic solvents in four industrial sectors:
paints & coatings basic organic chemicals
pharmaceuticals plastics & resins
1) www.regulations.gov/document?D=EPA-HQ-RCRA-2010-0742-0368
2) “Review: Membrane materials for the removal of water from industrial
solvents by pervaporation and vapor permeation” by L.M. Vane (in review).
• This project is carried out under the Sustainable & Healthy Communities
national research program.
The views expressed herein are those of the authors and do not necessarily represent
the views or policies of the EPA. The mention of trade names or commercial products
does not constitute an endorsement or recommendation for use.
Toluene* Methanol
Xylenes* Ethanol*
Ethylbenzene* 1-Butanol*
1,2,4-Trimethylbenzene Tetrahydrofuran*
Chlorobenzene* N,N-Dimethylformamide
n-Hexane* Acetonitrile*
Cyclohexane* Methyl isobutyl ketone*
Chloroform* Methyl tert-butyl ether*
Chloromethane Acetone
Dichloromethane* 2-Propanol*
* Solvent forms azeotrope with water Solvent to be highlighted in this project Related solvent to be included in study
In-house development, evaluation, and review of advanced separation materials & technologies for energy-efficient solvent re-processing.
o Focus on separating solvent/water mixtures because most of the 18 targeted solvents form azeotropic aqueous mixtures.
o Emphasize the membrane processes pervaporation (PV) and vapor permeation (VP) which have proven effective at efficiently separating azeotropic mixtures.
• PV/VP separate based on sorption & diffusion differences
Developing and Evaluating Membranes
• Lab- and pilot-scale PV and VP testing.
• Creating new materials and modifying existing materials.e.g. “Preparation of water-selective polybutadiene membranes and their use in drying alcohols by pervaporation and vapor permeation technologies,” Vane, Namboodiri, Lin, Abar, and Alvarez, ACS Sustainable Chemistry & Engineering, 4, 4442-4450 (2016).
e.g. U.S. Patent 9,266,803: “Liquid separation by membrane assisted vapor stripping process” (2016), Vane and Alvarez.
• Demonstrate Innovative TechnologiesCooperative R&D Agreement (CRADA) with Membrane Technology and Research, Inc., “Membrane-based processes for the separation of solvent/water mixtures”.
Opportunities for collaboration
We seek input and partners from the end-user, separations, and regulatory communities to ensure the project is relevant, practical, and useful.
o Also demonstrating desalination brine treatment technologies
A robust and varied industry has developed to provide PV/VP membranes and systems for solvent dehydration.
Membranes made from at least 7 water-selective materials are commercially available for this application:
o Inorganic materials: Zeolites (NaA, T-type, and Chabazite) and Hybrid Silica.
o Polymeric materials: Poly(vinyl alcohol), Polyimides, and Amorphous Perfluoropolymers.
Reviewed Water-Selective Membranes2
Design and Demonstrate Efficient Solvent Drying Processes
• Incorporate PV/VP into existing solvent reclaiming operations.
• We will leverage prior experience developing efficient processes for the recovery and drying of alcohol-based biofuels.
Solvent reclamation requires separation technologies to recover and purify them to meet reuse specifications.
Water can be a problematic contaminant when difficult-to-separate “azeotropic” mixtures form with solvents.
Conventional solvent separation technologies introduce significant material and energy demands.
o separation of azeotropic mixtures further increases complexity and resource usage.
To make solvent reclamation/reuse as environmentally beneficial as possible, efficient alternative separation technologies are needed.
The Challenge
Ethanol/Water Feed Mixture
DriedEthanol
Ethanol-Depleted Water
Condenser
Make-up steam/gas
VaporCompressor
Water-selective vapor permeation membrane
Water vapor recycle
Vapor stripping column
.