Membrane adsorber device

Abstract

The present invention is an adsorber membrane and a device containing one or more such membranes. Both the membrane and the device have a Peclet number (Pe) of at least 100. The membrane and the device are designed for the removal of trace contaminants in protein containing streams such as exist in the biopharmaceutical industry. A preferred membrane has tight pore size distribution and high permeabilities that allow for high throughput separations. A device of the present invention can contain a flat sheet membrane such as a pleated filter, a tangential flow filter or a spiral wound filter. Preferably, the device is formed in a stacked disk arrangement where one or more layers of membrane are sealed to each of the two large surface of the disk. One such device is formed of a series of disks, each disk having eight layers of membranes sealed to each of the two large surfaces of the disk. These disks are placed within a sealed capsule having an inlet on one end and an outlet on the other. The disks are sealed so that all fluid that exits the outlet does so by having first passed through the membranes on one side of a disk.

What I claim:  
     
         1 . A membrane adsorber device comprising a housing having an inlet and an outlet and one or more layer of an adsorptive membrane wherein the device has a Peclet number (Pe) of at least 100.  
     
     
         2 . The device of  claim 1  wherein the Pe is at least 150.  
     
     
         3 . The device of  claim 1  wherein the Pe is at least 200.  
     
     
         4 . The device of  claim 1  wherein the Pe is at least 500.  
     
     
         5 . The device of  claim 1  wherein the Pe is at least 2000.  
     
     
         6 . The device of  claim 1  wherein the Pe is from about 100 to about 4000.  
     
     
         7 . The device of  claim 1  wherein the one or more layers of membranes are formed on one or more porous disks with their inner and outer edges being sealed to the disks forming a space between the membranes and the disk into which filtered liquid can flow, an outlet from the disk for the filtered liquid.  
     
     
         8 . The device of  claim 1  wherein the one or more membranes have a Pe of at least 100.  
     
     
         9 . The device of  claim 1  wherein the one or more membranes have a Pe of at least 200.  
     
     
         10 . The device of  claim 1  wherein the one or more membranes have a Pe of at least 500.  
     
     
         11 . The device of  claim 1  wherein the one or more membranes have a Pe of at least 1000.  
     
     
         12 . The device of  claim 1  wherein the one or more membranes have a Pe in the range of from about 100 to about 4000.  
     
     
         13 . The device of  claim 1  further comprising a flow distributor located between the inlet and the one or more layers of membranes.  
     
     
         14 . A process for the removal of trace contaminants from an aqueous protein containing stream comprising the steps of selecting a membrane based adsorber device wherein the membrane and device each have a Pe of at least 100 and flowing an aqueous protein containing stream through said membranes of said device to remove any trace contaminants.  
     
     
         15 . The process of  claim 14  wherein the trace contaminants are selected from the group consisting of viruses, endotoxins, DNA, RNA and mixtures thereof.  
     
     
         16 . A process for determining the Peclet number of a membrane absorber comprising the steps of: (a) equilibrating the membrane or membrane adsorber device with an equilibration buffer at a known pH and conductivity; (b) challenging the membrane with a known concentration of a specific solute in the equilibration buffer; (c) monitoring the breakthrough of the solute downstream of the membrane as a function of value selected from the group consisting of time, challenge volume and other suitable variable related to total quantity of material challenged to membrane; (d) analyzing the solute breakthrough curve to determine pertinent flow characteristics of the membrane adsorber device; and (e) comparing the results calculated in step (d) to results from known integral devices.  
     
     
         17 . The method of  claim 16  wherein the analysis of (d) is by calculating the sharpness of the breakthrough curve.  
     
     
         18 . The method of  claim 16  wherein the monitoring of step (c) is by a detector.  
     
     
         19 . The method of  claim 16  wherein the analysis of (d) is by monitoring the time of solute breakthrough.  
     
     
         20 . The method of  claim 16  wherein the analysis of step (d) is by monitoring a variable related to total quantity of material challenged to membrane adsorber at a point in time selected from the group consisting of the initial onset of solute breakthrough and a fraction of solute breakthrough.  
     
     
         21 . The method of  claim 16  wherein the analysis of step (d) is by monitoring a variable related to total quantity of material challenged to membrane adsorber at a specific fraction of solute breakthrough.  
     
     
         22 . The method of  claim 16  wherein the analysis of step (d) is by monitoring a variable related to total quantity of material challenged to membrane adsorber at a specific fraction of solute breakthrough wherein that fraction is from about 5% to about 50%.  
     
     
         23 . The method of  claim 16  wherein the analysis of step (d) is by monitoring a variable related to total quantity of material challenged to membrane adsorber at a specific fraction of solute breakthrough wherein that fraction is from about 5% to about 20%.  
     
     
         24 . The method of  claim 16  wherein the analysis of step (d) is by monitoring a variable related to total quantity of material challenged to membrane adsorber at a specific fraction of solute breakthrough wherein that fraction is from about 5% to about 10%.  
     
     
         25 . The method of  claim 16  wherein the analysis of step (d) is by calculating a breakthrough curve sharpness and an initial onset of solute breakthrough.