Accession Number : ADA307353

Title :   Measurements of the Efficiency of a NASA/Air Force Alkaline Scrubber in Removing Waste NO2/N2O4 Vapors,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA TECHNOLOGY OPERATIONS

Personal Author(s) : Westberg, Karl

PDF Url : ADA307353

Report Date : 01 DEC 1995

Pagination or Media Count : 36

Abstract : An alkaline scrubber was installed at Vandenberg Air Force Base's Hypergolic Storage Facility (HSF) in late 1991 to remove waste N2O4/NO2 vapors in nitrogen diluent. A test was run on 13 December 1991 to determine this scrubber's efficiency. Measurements were made with the nitrogen diluent flowing at about 53 SCFM (standard cubic feet per minute) and at about 90 SCFM. The mole fractions of NOx and NO entering and leaving the scrubber were repeatedly measured in real time with a chemiluminescent analyzer. The mole fraction of NOx entering the scrubber was between 250,000 and 280,000 ppm in nitrogen. The mole fraction of NOx leaving the scrubber and vented into the atmosphere increased with increasing diluent flow rate. The measured mole fraction of NOx in the exhaust stream was 870 ppm when the nitrogen flow was 53 SCFM and 1675 ppm when the nitrogen flow was about 90 SCFM. The scrubber's performance matched that of similar scrubbers tested elsewhere. Over 99% of the N2O4/NO2 vapors were scrubbed even when the nitrogen diluent flow was 90 SCFM. Nevertheless, the maximum diluent gas flow through the scrubber has been limited to about 53 SCFM in accordance with the requirement set by the Santa Barbara Air Pollution Control District that the scrubber's exhaust plume be colorless. Air pollution regulations in Santa Barbara County require that the performance of the scrubbers at Vandenberg Air Force Base be remeasured every few years. Past performance measurements made by others have been highly inaccurate. This report discusses how to accurately measure both the amount of nitrogen oxides that enters the scrubber and the amount that leaves the scrubber and is exhausted into the atmosphere. Scrubber chemistry is discussed quantitatively in some detail.

Descriptors :   *EFFICIENCY, *WASTE DISPOSAL, *NITROGEN OXIDES, *SCRUBBERS, *ALKALINITY, REQUIREMENTS, REMOVAL, AIR POLLUTION, REAL TIME, NITROGEN, CHEMISTRY, AIR FORCE FACILITIES, ANALYZERS, REGULATIONS, EXHAUST PLUMES, STREAMS, GAS FLOW, CHEMILUMINESCENCE, DILUENTS.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Air Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE