Processing of Green Solvents

Solvents are valuable processing tools in the chemical and related industries used to enhance mass transfer, heat transfer and processing aids not used in the final product. Solvents are very valuable but cause significant problems with volatility and associated emissions. Manufacturing processes that utilize green technology or solvents for process improvement and reduced emissions are very desirable. This program addresses a family of green solvents that are superior to conventional solvents and have low volatility, resulting in fewer emissions problems.Compact Membrane Systems has developed an amorphous perfluoro membrane to enhance the use of these desirable green solvents. Recent developments allow working with green amorphous perfluoropolymers, specifically, the elimination of perfluoro octanoic acids (PFOA) in the synthesis of these 15 directly responsive to the EPA’s directive to eliminate PFOA surfactants. In Phase I, Compact Membrane Systems demonstrated in laboratory scale the concept of efficiently drying ionic liquids (ILs) for reuse using a perfluorinated composite membrane as well as the economic advantage. Ionic liquids are potentially advantageous in the processing/extraction of sugars from cellulosic biomass. Sugar recovery requires mixing the IL with water. The wet ionic liquid must be dehydrated for reuse. Efficient water removal from the ionic liquid was observed despite the low driving force for water permeation. The water permeance was approximately constant over a wide range of water concentration and temperature. Permeation of the IL through the membrane is negligible, resulting in extremely high water/IL separation factors. This leads to quantitative recovery of the IL, which is critical for low-cost pretreatment of biomass.In Phase II, Compact Membrane Systems will scale up the membrane system and build a pilot test unit to demonstrate the concept in pilot scale. The membrane system and process conditions to achieve IL dehydration for recycle will be optimized. Through a long-term test, the company will demonstratesystem performance stability and resistance to process upsets such as daily startups and shutdowns. Using the pilot scale data, Compact Membrane Systems will conduct an engineering and economic analysis to highlight the economic advantage of the proposed concept versus conventional technologies suchas evaporation and will verify that the IL can still pre-treat cellulosic biomass after multiple membrane dehydration cycles. Several organizations, including pioneers in the development and use of ionic liquids for processing biomass, are interested in partnering with Compact Membrane Systems regarding the development and implementation of methods for dewatering ionic liquids.