An Efficient PFO-SPS System for Concentration of Brines and Wastewater Using Low Enthalpy Geothermal Heat

This Small Business Innovation Research Phase I project will develop the design of a system concentration of brines and wastewater using low enthalpy geothermal heat. The system combines a forward osmosis (FO) membrane with a thermally switchable draw. Forward osmosis technology excels in processing difficult-to-treat waters, such as brines and oil and gas wastewater. Porifera’s FO membrane has higher flux and reduced reverse salt flux compared to conventional membranes. It is more chemically stable, enabling the development of a system that uses a draw solute which can recovered using low-grade heat from geothermal sources. The draw solute can obtain high osmotic pressure and is recyclable for reuse within the system. Compared to other state of the art technologies, the system will have higher water recovery and treat more problematic water using low-enthalpy geothermal heat to drive the system. Concentration of brines and wastewater is an energy intensive process and does not utilize available geothermal heat. This proposal will enable the design of a pilot system that will concentrate brines and wastewater using low enthalpy geothermal heat. The system will have higher water recovery and treat more problematic water using less energy compared to state of the art technologies. For this SBIR Phase I project we will first identify a target pilot site for demonstration of the technology and then design and specify the components of the pilot system. We will target customers in the oil and gas industry, geothermal brines for mineral recovery, or power plant wastewater treatment.