Date of Award

1-31-1992

Document Type

Thesis

Degree Name

Master of Science in Applied Chemistry - (M.S.)

Department

Chemical Engineering, Chemistry and Environmental Science

First Advisor

Henry Shaw

Second Advisor

Howard David Perlmutter

Third Advisor

Barbara B. Kebbekus

Abstract

The selective removal of nitric oxide from gas streams was investigated using 3,6-dimethyl-3-octyl hydroperoxide, p-menthane hydroperoxide, pinane hydroperoxide, and cumene hydroperoxide in solutions of n-hexadecane (cetane). The influence of different parameters such as temperature, gas stream flow rate (or residence time), and concentration of hydroperoxide compounds on efficiency of NO removal was evaluated. The basis of this research was to duplicate atmospheric reactions between hydroperoxides and NO in order to produce NO2. We succeeded in removing NO from gas streams, but failed to produce NO2. NO reacted with the hydroperoxides to produce nitrates. These nitrates are easily hydrolyzed with ammonium hydroxide to ammonium ni¬trates and alcohols. The hydroperoxides used in this study were selected to be inexpensive and commercially available, low vapor pressure to avoid loss of reagent when contacted with hot flue gas, and easily regenerated. This research was conducted in a scrubbing reactor system with associated feed and products flow measurement equipment. The reactor consisted of a fritted disk through which a gas stream of NO in helium was bubbled into the hydroperoxide solution. Feed and effluent gas stream were analyzed using a gas chromatograph (GC) with a thermal conductivity detector (TCD) or a chemiluminescent NOx analyzer. A Fourier transform infrared spectrometer (FTIR) was used to determine organic product distribution and an ion chromatograph (IC) was used to measure inorganic products from the hydrolysis, and from an aqueous scrubber used to detect NO2.

Higher rates of oxidation were obtained with cumene and pinane hydroperoxide than with the other two organic hydro-peroxides tested. The highest rates of NO removal were ob¬tained at the highest temperatures, highest concentrations, and lowest gas flow rates. With p-menthane hydroperoxide as the oxidizer, the main product is p-menthane nitrate. No NO2 was produced. Consequently, it is assumed that the main product from the other hydroperoxides is also the nitrate. In this research, excellent nitrogen mass balance were obtained to within 100 + 10% with p-menthane hydroperoxide. Again it is assumed that equivalent material balances are achieved with the other hydroperoxides.

p-Menthane nitrate can be efficiently denitrated in dilute aqueous ammonia to produce ammonium nitrate and menthanol. Some experiments were conducted with hydroperoxylated polypropylene fibers as a solid oxidizer to remove NO. High rates of removal of NO was achieved at similar condi¬tions to those used with the liquid hydroperoxides, namely, high temperature, high concentration of the hydroperoxide group, and low gas flow rate (high residence time).

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