Lower Net Pressure Reverse Osmosis Membranes and Systems - Cost and Performance Advantages and Limitations

摘要

Reverse osmosis systems are generally designed and utilized on the basis of reference membrane water flux and desalting performance at 400 psi net driving pressure (NDP). Membranes now being offered and tested at a preliminary commercial stage are capable of equivalent performance at 200 psi NDP. These membranes offer immediately obvious savings in energy costs for reverse osmosis desalting and water reclamation. In addition, they can make a most important contribution to reduced membrane replacement costs and improved permeate quality when operating on high salinity feeds at higher recovery levels. A number of hypothetical cases were developed and tabulated, assuming a 200 psi NDP sea water membrane was available. Substantial benefits could be expected if such a membrane could be developed and reduced to practice. Additional cost savings and performance improvements can be realized by operating the 200 psi NDP membranes at somewhat higher applied pressures which preserve or enhance NDP.