Browse Prior Art Database

HOLLOW FIBER ULTRAFILTRATION MODULE WITH COMPOSITE CERAMIC-POLYMER MEMBRANE

IP.com Disclosure Number: IPCOM000224147D
Publication Date: 2012-Dec-11
Document File: 4 page(s) / 121K

Publishing Venue

The IP.com Prior Art Database

Abstract

This invention relates to ultrafiltration module for water treatment. The invention is a hollow fiber ultrafiltration module with composite ceramic-polymer membrane. The module design is a hollow fiber module, with the fibers comprising a thin flexible ultrafiltration membrane consisting of a thin ceramic porous layer (anodized alumina) with pore size between 5 and 500 nm and thickness less than 3 microns, disposed on a porous polymeric support. The ceramic layer by nature of its method of production, has a tight pore size distribution with a tunable size ranging from 5 to 500 nm. These pore sizes correspond to the microfiltration (>200 nm), ultrafiltration (200 to 10 nm), and nanofiltration (<10 nm) ranges. The advantages of the composite membrane include permeability up to an order of magnitude higher than a comparably rated polymer UF membrane, with equivalent selectivity. The invention is also a method for filtering fluids using said module. The filtration can be performed in either dead end or cross-flow modes. In produced water applications such as water treatment for heavy oil production or shale gas frac flowback, such membranes could be used to separate oil emulsion droplets from water.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 43% of the total text.

HOLLOW FIBER ULTRAFILTRATION MODULE WITH COMPOSITE CERAMIC-POLYMER MEMBRANE

BACKGROUND

This invention relates to ultrafiltration module for water treatment. The invention addresses the problem of improving the economics and efficacy of membrane filtration for oil removal applications. Current membrane economics are driven by the required area and the operating performance for given throughput. To achieve a particular pore size cut-off, it is necessary to set the target pore size to ensure that the tail of the distribution with larger pore sizes does not compromise the performance. Polymeric membranes are formed by a process that results in a relatively broad pore size distribution. Anodized aluminum oxide (AAO) membranes have a tighter pore size distribution which leads to a higher permeance entitlement because there is a greater areal density of pores. However, AAO membranes are difficult to manufacture as high flux components. This is because the structure must be sufficiently thick to ensure mechanical stability.

Prior attempts to filter water using AAO membranes have been performed on free-standing filters. These have been successful at small scales (up to 47 mm discs), but is not practical at larger scales, which are necessary for commercial use in the water filtration applications described earlier. There have been efforts to filter viruses using a block copolymer-based separation layer (Yang et al. 2006). This invention overcomes the problem of maintaining the benefits of an AAO membrane, along with the scalability of polymer-based membranes, for the filtration applications of interest.

BRIEF DESCRIPTION OF DRAWINGS

Hollow fiber ultrafiltration module with composite ceramic-polymer membrane is disclosed with reference to the following drawings in which:

Figure 1 shows a comparison of permeability against separation factor for the IAAO membrane of the invention.

Figure 2 shows the construction of filtration modules incorporating IAAO membrane.

DETAILED DESCRIPTION

The invention is a hollow fiber ultrafiltration module with composite ceramic-polymer membrane. The module design is a hollow fiber module, with the fibers comprising a thin flexible ultrafiltration membrane consisting of a thin ceramic porous layer (anodic alumina) with pore size between 5 and 500 nm and thickness less than 3 microns, disposed on a porous polymeric support. The ceramic layer is anodized aluminum oxide, which by nature of its method of production, has a tight pore size distribution with a tunable size ranging from 5 to 500 nm. These pore sizes correspond to the microfiltration (>200 nm), ultrafiltration (200 to 10 nm), and nanofiltration (<10 nm) ranges. By disposing the ceramic on a porous hollow fiber polymeric support such that the ceramic layer is thin, advantages in flux are achieved while maintaining selectivity provided by the pore size. A plot of performance for the composite structure (IAAO), relative to conventional polymeric membranes, and free-stan...