Grantee Research Project Results
Final Report: Power Production through the use of Pressure Retarded Osmosis and Solar Distillation Ponds
EPA Grant Number: SU835687Title: Power Production through the use of Pressure Retarded Osmosis and Solar Distillation Ponds
Investigators: Venkatadriagaram, Sundararajan
Institution: University of California - Riverside
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 15, 2014 through August 14, 2015
Project Amount: $14,999
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2014) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Air Quality , P3 Challenge Area - Safe and Sustainable Water Resources , P3 Awards , Sustainable and Healthy Communities
Objective:
The purpose of this project was to create a hardware prototype of a closed loop power generating system. The prototype consists of three subsystems: 1) membrane, 2) solar distillation, and 3) turbine. The membrane housing used for testing is composed of a two plastic plates specifically milled to support the structure of the membrane while allowing the necessary flows. The two plates sandwich the membrane and are sealed with an o-ring. The flow of water produced by the osmosis of fresh water into the higher salinity water is made to pass through a turbine to produce energy. The solar distillation used in this project includes two heat exchangers in order to separate the salt and fresh water for it to be reusable. The the prototype consists of PVC pipes connecting to the membrane housing where the salinity gradient will cause an osmotic pressure and drive fresh water flow through.
Summary/Accomplishments (Outputs/Outcomes):
In Phase I, we restricted our scope to a small scale closed loop system that can be tested in a laboratory environment. This consisted of testing for a closed loop system; however, in order to properly test for closed loop system, membrane testing was necessary to determine permeability. The membranes tested consisted of HTI’s OsMem CTA-NW membrane and CTA-3H membrane. The key concept for this design was to create a module which would facilitate easy membrane replacement when testing different flow rate patterns and pressures. Testing the HTI Membrane: The goal of the test was to determine the permeate flux of fresh water pressure between the separated water zones. Results determined that as concentration differences increase, the osmotic pressure and water flow will increase. The CTA-NW membrane produced less pressure in comparison to the CTA-3H membrane. Tests were performed with a salt concentration of 35 gl-1, a molar concentration of .589 mol l-1, and a room temperature of T=298K.
Conclusions:
The team currently is testing nano filtration membranes in order to test higher concentrations of salt water. The team is also continuing testing Porifera membrane testing. However, calculations showed that solar distillation of water is infeasible for producing a net gain of electrical generation for the PRO system. To make the system feasible, alternate solutions need to be investigated.
The 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.