Grantee Research Project Results
Final Report: On-Site Recovery of Glycols from Airport Deicing Fluid Using Polymeric/Ceramic Composite Membranes
EPA Contract Number: 68D60058Title: On-Site Recovery of Glycols from Airport Deicing Fluid Using Polymeric/Ceramic Composite Membranes
Investigators: Liu, Paul K.T. , Ciora, Richard J.
Small Business: Media and Process Technology Inc.
EPA Contact: Richards, April
Phase: II
Project Period: September 1, 1996 through September 1, 1998
Project Amount: $225,000
RFA: Small Business Innovation Research (SBIR) - Phase II (1996) Recipients Lists
Research Category: Watersheds , SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)
Description:
As a result of governmental regulation and the inadequacies of conventional treatment technology, waste aircraft deicing fluid has become both an economic and environmental liability for airports throughout the US and Canada. About 200 to 600 million gallons of spent aircraft deicing fluid containing >1 to ca. 35 vol% glycol are generated per year at over 1,500 airports throughout the U.S. and Canada today. The EPA has classified this material as a regulated industrial process wastewater under the NPDES 40 CFR Part 122. As a result, disposal of spent deicing fluid has become both an environmental and economic liability and very few airports today have successfully fulfilled the requirements set forth by the EPA. Media and Process Technology, Inc. (M&P) has developed a hybrid process for spent aircraft deicing fluid recovery employing (i) an innovative polymeric/ceramic composite membrane based vapor permeation technology, and (ii) a low cost high performance ceramic ultrafiltration membrane technology. This simple hybrid technology overcomes the problems associated with conventional deicing fluid technology (distillation, reverse osmosis, biofiltration, etc.) to deliver high purity glycol from spent deicing fluid.Summary/Accomplishments (Outputs/Outcomes):
To produce a saleable product, it is necessary to reduce the water content as well as remove the turbidity, color, odor, and various other contaminants from spent aircraft deicing fluid. Water can be removed via conventional evaporation technology, although by comparison, vapor permeation with an innovative polymeric/ceramic composite membrane (PCC Membrane) developed by M&P has a variety of advantages. Additionally, M&P's low cost high performance ceramic ultrafiltration membranes and proprietary polishing technology had been demonstrated for turbidity, color, and odor removal in the recycling of spent aircraft deicing fluid. Economic projections and bench treatability tests showed that these technologies could be integrated to deliver a viable process for the production of high quality propylene glycol from spent deicing fluid.In general in our process, spent deicing fluid is first chemically pretreated to remove contaminants and additives. It is then filtered to remove particulate debris, suspended solids and turbidity at high temperature (75 to 95 C) using proprietary/patented ceramic ultrafiltration membrane technology developed by M&P. Next, the deicing fluid is dewatered in the vapor phase via the PCC Membrane or conventional distillation technology to the final product concentration. Finally, a proprietary polishing step is used to polish the crude product to produce a finished glycol for resale. The salability of this product has been established by our Phase III commercialization partner. Based upon an established market value of $3.40 per gallon of recycled propylene glycol, excellent profitability is achieved.
In the pre-treatment step, proprietary chemicals are employed to precipitate the corrosion inhibitors and inorganic contaminants commonly found in the spent deicing fluid. >90% removal efficiency can be achieved using the M&P formulation. The high temperature ceramic membrane filtration process was developed to effectively and efficiently remove residual particulates, emulsified oil and others to deliver a clear salable glycol/water mixture. More importantly, the viscosity modifier commonly used in the deicing fluid was removed via this high efficiency ultrafilter. The high temperature filtration offers unique process advantages in enhancing throughput and reducing fouling potential. The use of this highly effective ultrafilter is critical to (1) prevent fouling and enhance the efficiency of the polishing step and to (2) keep the cost of the polishing step to a minimum.
With the PCC Membrane, the spent deicing fluid is first partially vaporized then passed over the membrane surface at temperatures in excess of 135?C. Water vapor preferentially permeates the membrane leaving an enriched glycol stream behind. The chemical oxygen demand (COD) of the permeate water was less than 800ppm and therefore suitable for direct discharge to many POTW's. This type of membrane is attractive in comparison to conventional technology for a number of reasons, specifically, (i) there is no limitation as to the enrichment that can be achieved (unlike reverse osmosis), (ii) fluctuations in feed glycol content can be easily handled (unlike distillation), (iii) glycol recovery can be practiced (unlike biodegradation), (iv) wastewater produced with this process could be directly discharged to a POTW (unlike distillation), (v) foaming of the feed sample due to the surfactants is not a problem (unlike distillation), and (vi) on-site unattended mode operation is possible. If conventional distillation technology is used for dewatering, the PCC membrane is an excellent add-on technology to reduce the COD of the overhead condensate to meet the discharge requirement.
Conclusions:
The M&P deicing fluid recovery technology consists of chemical pretreatment followed by high temperature ceramic ultrafiltration for the removal of additives, contaminants, suspended solids, and others, and high temperature vapor permeation to dewater the spent deicing fluid to a desirable glycol concentration. Then, a proprietary polishing step is used to remove trace contaminants to deliver a high quality propylene glycol product for resale. This process has the potential to eliminate the twin environmental and economic problem of spent deicing fluid management faced by airports throughout the U.S. and Canada.Commercialization Status:
Pretreatment of spent deicing fluid using the M&P ceramic membrane has been commercialized by M&P. One full-scale ultrafiltration system has been installed and integrated into the existing deicing fluid recovery process in a major US airport. Presently M&P is participating in the pilot testing program using its ceramic membrane as pre-treatment for reverse osmosis to concentrate the dilute (i.e., 1 to 3%) deicing fluid to ~10%. In addition, a pilot testing has been conducted to successfully demonstrate the developed technology for pre-treatment of spent thylene glycol (automobile antifreeze) before re-refining with the conventional distillation process. Based upon the positive results from these two pilot tests, the full scale systems are expected to be installed in the near future. The PCC membrane is currently under further manufacturing development by M&P.
Supplemental Keywords:
deicing fluid, ceramic membrane, membrane, ultrafiltration, glycol, polymeric-ceramic composite membrane., Scientific Discipline, Water, Sustainable Industry/Business, Chemical Engineering, cleaner production/pollution prevention, Wastewater, Environmental Chemistry, Chemistry, Engineering, Chemistry, & Physics, Environmental Engineering, hazardous liquid waste, ceramic membrane, glycol recovery, wastewater treatment, industrial wastewater, cleaner production, clean technology, membrane filtration, membrane-based, pollution control, aircraft deicing, glycols, polymeric membrane, control technologies, airport deicing, pollution prevention, aqueous waste streamSBIR Phase I:
On-Site Recovery of Glycols from Airport Deicing Fluid Using Polymeric/Ceramic Composite MembranesThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.