Rate constants for the reactions H02 + O (1) and H02 + H (2) were measured in a discharge-flow apparatus fitted with back-to-back laser-induced fluorescence and vacuum UV resonance fluorescence detectors. The decays of [O] and [H] were monitored under conditions of large excess H02, generated by F + H202 and detected as OH after conversion with added excess NO. kl and k2 were found to be (5.4 ± 0.9) X 10"11 and (7.4 ± 1.2) X 10~n cm1 23 s'1, respectively. The branching ratios of (2), whose three sets of products are OH + OH (2a), H20 + O (2b), and H2 + 02 (2c) were determined by reacting small, known concentrations of H02 with large excess of H and measuring the [OH] and [0] formed. They were found to be 0.87 ± 0.04, 0.04 ± 0.02, and 0.09 ± 0.045, respectively. These results are compared with published data and discussed in terms of the likely course of the molecular interactions.

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An experimental study of the title reaction over the temperature range 250 to 459 K is described that uses the discharge-flow technique, laser-induced–fluorescence detection of OH and simultaneous monitoring of O and H atoms. In a teflon or halocarbon wax-coated flow tube, the reaction is well behaved and free from surface effect interference, but this is not true on clean Pyrex. OH radicals are generated in three different ways and at low initial concentrations (4 to 8×1010 cm−3) in order to eliminate side reactions. The rate constant is found to be (1.69±0.26)×10−12 at 298 K and (2.96±0.50)×10−12 exp[−(164±52)/T] cm3 s−1 over the above temperature range, a factor of two higher at 298 K and factors of 3 to 5 higher at 10 to 30 km altitude in the terrestrial atmosphere than earlier studies have indicated. These studies are re-examined, and for several of them, arguments are presented that reduce the discrepancy. The effects of the higher rate constant on atmospheric processes and on some recent laboratory measurements of other reactions are discussed briefly.

Naphthenic acid is a generic name used for all the organic acids present in crude oils. The quantitative determination of naphthenic acid number (NAN) is an essential parameter for petroleum refineries to evaluate corrosive properties of crude oils prior to their processing. Currently, most of the refineries are using total acid number (TAN) as a measure of corrosivity of crudes during their selection, valuation, and processing. Some of the organic molecules are being used as corrosion inhibitors to reduce corrosion in refinery process units, and the dosage of the same depends on the total acid number as it has been understood from the studies that acid inhibitors form a protective layer on the surface of the pipes and thus reduces the corrosion due to acids present in crude oil. TAN measurement by titration overestimates the acid number as each and every molecule like thiols and phenols etc. that are titratable by alkali are also included in the calculation and that causes the improper estimation of the addition of corrosion inhibitors. To get a better refinery margin in the present economic scenario, optimization of the addition of corrosion inhibitors is very much essential and thus accurate measurement of NAN is a primary concern. Hence, we present a quick and efficient mid-Fourier transform infrared (FTIR) spectroscopic method for the determination of NAN using a variable path length liquid cell with calcium fluoride windows. Two distinct photon absorption bands in the region of 1680 to 1800 cm–1 were observed during the spectral measurement and are due to the formation of monomeric and dimeric forms of carbonyl (CO) group of carboxylic acids, and hence both are considered for the quantification. The method is applicable even to highly volatile crude oils that are not measurable by the normal attenuated total reflectance (ATR)-FTIR technique. This article also presents the effect of solvents, hydrogen bonding, formation of monomer and dimer, etc. Currently, this method is being applied for the determination of NAN for crude oils and straight run vacuum gas oil (VGO) samples as they contain either negligible or no carbonyl compounds other than carboxylic acids that interfere in the region of interest.