Accession Number : ADA294695

Title :   Heterogeneous-Phase Reactions of Nitrogen Dioxide With Vermiculite-Supported Magnesium Oxide (As Applied To The Control of Jet Engine Test Cell Emissions).

Descriptive Note : Doctoral thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Kimm, Larry T.

PDF Url : ADA294695

Report Date : 1995

Pagination or Media Count : 216

Abstract : Controlling nitrogen oxides (NO(x)) from a non-steady-state stationary source like a jet engine test cell (JETC) requires a method that is effective over a wide range of conditions. A heterogeneous, porous, high surface area sorbent material comprised of magnesium oxide powder attached to a vermiculite substrate has been commercially developed for this purpose. Data from extensive laboratory testing of this material in a packed-bed flow system are presented. NO2 removal efficiencies, kinetics, and proposed NO2 removal mechanisms over a range of representative JETC exhaust gas characteristics are described. Exhaust gas variables evaluated included: NO2 concentration, temperature, flow rate (retention time), oxygen content and moisture content. Availability of water and oxygen were found to be important variables. It is probable that water is necessary for the conversion of MgO to Mg(OH)2, which is a more reactive compound having thermal stability over the range of temperatures evaluated. Gaseous oxygen serves to oxidize NO to NO2, the latter being more readily removed from the gas stream. The presence of oxygen also serves to offset thermal decomposition of NO2 or surface nitrite/nitrate. Effective 'lifetime' and regenerability of the exposed sorbent material were also evaluated. NO2 removal efficiencies were found to greatly exceed those for NO, with a maximum value greater than 90 percent. The effective conversion of NO to NO2 is a crucial requirement for removal of the former. The reaction between NO2 and MgO-vermiculite is first-order with respect to NO2. jg

Descriptors :   *JET ENGINES, *CHEMICAL REACTIONS, *MAGNESIUM OXIDES, *NITROGEN DIOXIDE, TEMPERATURE, LABORATORY TESTS, EXPOSURE(GENERAL), WATER, POWDERS, COMPOSITE MATERIALS, REACTIVITIES, THERMAL STABILITY, TEST EQUIPMENT, SUBSTRATES, MOISTURE CONTENT, TIME, VARIABLES, IRON, SURFACES, OXYGEN, FLOW RATE, ABSORBERS(MATERIALS), ALUMINUM, NITROGEN OXIDES, SILICATES, MINERALS, PYROLYSIS, GAS FLOW, ADSORBENTS, NITRATES, EXHAUST GASES, NITRITES.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE