FREON-TYPE, SOLVENT-RECYCLING SPRAY BOOTH

THIS PROPOSAL DESCRIBES THE DESIGN OF A SOLVENT SPRAY BOOTH THAT USES A MEMBRANE SYSTEM TO RECOVER AND RECYCLE SOLVENT. SOLVENT SPRAY CLEANING AND SOLVENT DEGREASING SYSTEMS ARE WIDELY USED IN A NUMBER OF CRITICAL CLEANING APPLICATIONS IN THE AEROSPACE INDUSTRY. CLEANING BOOTHS USE CFC-113, 1,1,1-TRICHLOROETHANE AND VARIOUS HCFC SOLVENTS. EMISSION OF THESE SOLVENT VAPORS TO THE ATMOSPHERE IS NO LONGER ACCEPTABLE. THE AIR FORCE IS INTERESTED IN DEVELOPING SOLVENT SPRAY BOOTH/VAPOR DEGREASER SYSTEMS THAT CONTAIN THE SOLVENTS AND CAN RECYCLE ANY VAPORS PRODUCED BACK TO THE SYSTEM. MEMBRANE TECHNOLOGY AND RESEARCH, INC. (MTR) HAS BEEN DEVELOPING MEMBRANE-BASED CFC/AIR SEPARATION SYSTEMS FOR SEVERAL YEARS AND HAS INSTALLED A NUMBER OF SMALL COMMERCIAL UNITS. THESE UNITS ARE ABLE TO REMOVE 98-99% OF CFC VAPORS FROM EFFLUENT AIR STREAMS, PRODUCING A CONCENTRATED CFC-CONTAINING PERMEATE STREAM THAT CAN BE RECYCLED. MTR BELIEVES THAT MEMBRANE-BASED SOLVENT RECOVERY UNITS OF THIS TYPE WOULD FORM AN IDEAL BASIS FOR THE ENVIRONMENTALLY ACCEPTABLE SYSTEMS THAT DOD REQUIRES. MEMBRANE TECHNOLOGY HAS MANY COMPELLING ADVANTAGES OVER CARBON ADSORPTION OR CRYOGENIC RECOVERY. IN THE PHASE I PORTION OF THIS PROGRAM, MTR PROPOSES TO SELECT AN EXISTING SPRAY BOOTH/VAPOR DEGREASER SYSTEM THAT CAN BE MODIFIED TO ACCEPT A TAILOR-MADE MEMBRANE SOLVENT RECOVERY AND RECYCLE SYSTEM. A COMPLETE DESIGN FOR THIS UNIT INCLUDING APPROPRIATE EMISSIONS MONITORING INSTRUMENTATION WILL BE PREPARED. IN THE PHASE II PROGRAM, THE COMPLETE UNIT WOULD BE CONSTRUCTED AND EVALUATED, FIRST IN THE LABORATORY AND LATER AT A DOD SITE. IT IS ESTIMATED THAT UP TO 300,000 TONS OF SOLVENT ARE EMITTED BY SOLVENT-CLEANING OPERATIONS ANNUALLY. A SPRAY BOOTH FITTED WITH MEMBRANE SYSTEMS TO ESSENTIALLY ELIMINATE SOLVENT EMISSIONS AND RECOVER THE SOLVENT FOR REUSE WOULD FIND NUMEROUS APPLICATIONS THROUGHOUT THE AEROSPACE, ELECTRONICS, PHARMACEUTICAL, AND OTHER "HIGH-TECH" INDUSTRIES.