Purification of organic solvent fluids

Abstract

A chemical distribution system having improved organic solvent fluid purity and consistency includes a vessel containing ion-exchange media positioned within a fluid flow pathway such that the organic solvent fluid passes through the ion-exchange media, thereby effecting removal of undesired impurities. Different embodiments of the invention position the vessel at varying locations within the fluid flow pathway. The chemical distribution system also preferably includes a return chemical flow pathway that recirculates purified organic solvent fluid through the ion-exchange media-containing vessel and thereby enables the system operator to conduct incremental adjustment of the solvent purity until a desired overall purity is attained.

1 . A method of reducing the number of metallic and ionic impurities in an organic solvent fluid supplied to a purification system by a solvent supply source, comprising: 
 positioning a vessel within a fluid flow pathway including a return chemical flow pathway that recirculates the organic solvent fluid through at least a portion of the fluid flow pathway and a fluid outlet, the vessel containing an ion-exchange media having electrically charged species that ionically interact with the metallic and ionic impurities in the organic solvent fluid such that these impurities are removed from the organic solvent fluid as the fluid passes through the ion-exchange media; and    directing the organic solvent fluid through the vessel multiple times such that a desired organic solvent fluid purity level may be achieved by controlling the number of times the organic solvent fluid passes through the ion-exchange media and thereby incrementally adjusting the purity level of the organic solvent fluid until a desired purity level is attained.    
   
   
       2 . The method of  claim 1 , in which the chemical purification system includes a chemical distribution module that supplies a motivating force that pumps the organic solvent fluid out of the solvent supply source.  
   
   
       3 . The method of  claim 2 , in which multiple chemical distribution modules supply the motivating force.  
   
   
       4 . The method of  claim 1 , in which the vessel including the ion-exchange media is located within the chemical distribution module.  
   
   
       5 . The method of  claim 1 , in which the vessel including the ion-exchange media is positioned adjacent to the solvent supply source.  
   
   
       6 . The method of  claim 1 , in which the vessel including the ion-exchange media is positioned adjacent to the fluid outlet.  
   
   
       7 . The system of  claim 2 , in which the vessel including the ion-exchange media is positioned between the organic solvent supply source and the chemical distribution module.  
   
   
       8 . The method of  claim 2 , in which the vessel including the ion-exchange media is positioned between the chemical distribution module and the fluid outlet.  
   
   
       9 . The method of  claim 1 , in which the chemical purification system includes multiple vessels.  
   
   
       10 . The method of  claim 9 , in which the multiple vessels are positioned in parallel alignment.  
   
   
       11 . The method of  claim 9 , in which the multiple vessels are positioned in series alignment.  
   
   
       12 . The method of  claim 1 , in which the ion-exchange media is of a macroporous type.  
   
   
       13 . The method of  claim 1 , in which the ion-exchange media is of a strong acid type.  
   
   
       14 . The method of  claim 1 , in which the ion-exchange media is of a strong base type.  
   
   
       15 . The method of  claim 1 , in which the ion-exchange media is a mixture of a macroporous strong acid type media and a macroporous strong base type media.  
   
   
       16 . The method of  claim 1 , in which the vessel contains multiple types of ion-exchange media.  
   
   
       17 . The method of  claim 1 , in which the lower purity organic solvent fluid includes an amphiprotic organic solvent.  
   
   
       18 . The method of  claim 17 , in which the amphiprotic organic solvent is selected from the group consisting essentially of isopropanol, ethanol, ethyl lactate, n-butyl acetate, ethylene glycol, cyclopentanone, and mixtures thereof.  
   
   
       19 . The method of  claim 1 , in which the lower purity organic solvent fluid includes a polar aprotic solvent.  
   
   
       20 . The method of  claim 19 , in which the polar aprotic solvent is selected from the group consisting essentially of acetonitrile, acetone, dimethylformamide, and mixtures thereof.  
   
   
       21 . The method of  claim 1 , in which the lower purity organic solvent fluid includes an aromatic compound.  
   
   
       22 . The method of  claim 21 , in which the aromatic compound is selected from a group consisting essentially of benzocyclobutene, polyaryl ethers, and mixtures thereof.  
   
   
       23 . The method of  claim 1 , in which the lower purity organic solvent includes a dielectric precursor fluid.  
   
   
       24 . The method of  claim 23 , in which the dielectric precursor fluid is selected from a group consisting essentially of tetraethylsilicate, porous or non-porous organic silicate esters, fluorinated organic silicate esters, perfluorocyclobutenes, hydrogen silsequioxanes, methyl silsequioxane and mixtures thereof.  
   
   
       25 . The method of  claim 1 , in which the organic solvent fluid is an edge-bead removal chemical.  
   
   
       26 . The method of  claim 1 , in which the edge-bead removal chemical includes a lactate solvent.  
   
   
       27 . The method of  claim 1 , in which the impurity is selected from a group consisting essentially of aluminum, antimony, arsenic, barium, beryllium, bismuth, boron, cadmium, calcium, chloride, chromium, cobalt, copper, gallium germanium, gold, iron, lead, lithium, magnesium, manganese, molybdenum, nickel, niobium, potassium, silver, sodium, strontium, tantalum, thallium, tin, titanium vanadium, zinc, and zirconium.  
   
   
       28 . The method of  claim 1 , in which the rate of flow of the organic solvent fluid passing through the fluid flow pathway is substantially constant such that the incidence of impurities being dislodged from the system is minimized.  
   
   
       29 . The method of  claim 1 , in which the purification system further includes a storage tank forming a secondary supply source that supplies organic solvent fluid to the fluid flow pathway.