This technology relates to a reinvention of the structure of spiral wound membrane module to increase productivity and to simplify the membrane fabrication process. Despite undergoing a long history of development, the structure of the spiral wound membrane modules remained the same. Each module is made up of several leaf sets, with each leaf set consisting of feed spacers, flat sheet membranes and a permeate carrier wrapped around the permeate collecting tube.
The technology here involves combining the 3 layers in a leaf set into 2 layers on an industrial-scale casting line such that more membrane can fit into a standard specific volume. By combining the permeate carrier and the membrane into a single sheet, we were able to eliminate the need for the typical non-woven backing for the membrane. As such, the leaf set thickness can be significantly reduced by approximately 10-20%, and hence the theoretical surface area and productivity of the membrane modules can be increased by 30-50%.
The material cost can potentially be reduced by 10-20% and the internal ion concentration polarization (ICP) is expected to be reduced due to less bulky structure. This design also lessen the work required to roll an element due to less sheets per leaf-set. The technology provider is currently seeking joint-venture partners for technology evaluation licensing with research collaboration agreement (RCA) to scale-up and commercialize the technology.
The membrane may be used for pressure driven water purification processes, e.g. Ultraflltration (UF), Forward Osmosis (FO), Reverse Osmosis (RO), Nanofiltration (NF), Pressure Retarded Osmosis (PRO), Microfiltration (MF).
Overall leaf set thickness in spiral wound membrane module is the key factor affecting performance in terms of pressure driven product throughput. In the reinvented design, the permeate carrier and the membrane combine into a single sheet which eliminated the typical non-woven support layer. As such, the leaf set thickness was significantly reduced and the productivity of the module can be improved as more membranes could be rolled within the same standard housing. Membrane SWM modules using the reinforced membranes have the potential to be the next low energy workhorse of the water industry