NOX box

Figure 13 Observed ozone production rates (P(03)) and concentrations of HO 2 and OH during SONEX (8-12 km altitude, 40-60° N latitude) plotted a function of the NOx concentration (NOx = observed NO + modelled NO2) The observed rates and concentrations are averaged over 24 h, using did factors obtained from a locally constrained box model. The lines on the three panels correspond to model-calculated values for median upper tropospheric conditions as encountered during SONEX ...

N and ppm levels of various metals such as vanadium and nickel). These elements are harmful to the environment, as upon combustion they produce SOx and NOx gases (responsible for acid rain), and to the chemical industry, as these molecules can poison the catalysts needed for the subsequent cracking and reforming operations (see Box 2, and Chapter 1, Section 1.2.1). 

SAFETY PROFILE Confirmed carcinogen. It will ignite in contact with ait or water. When heated to decomposition it emits toxic fumes of BeO, BOx, and NOx. See also BERYLLIUM COMPOUNDS and BORON COMPOUNDS. 

Patents were filed by Babcock Wilcox [21-23] concerning the so-called SOx-NOx-Rox Box process, according to which, in line with Fig. 6b, contemporary SO2 and NOx removal (the former by adsorption on lime, the latter by catalytic reduction with ammonia) is accomplished by the use of catalytic filters, prepared as described in Section III. A schematic of the catalytic baghouse assembly is presented in Fig. 7. The results of the application of such technology to the treatment of a lab-scale atmospheric fluidized-bed coal boiler (capacity 0.5 MWe) were reported in Refs. 9 and 29. The achieved abatement efficiencies were 70-80% for SO2, 90% for NOx(NH3/NO ratio = 1 ammonia slippage = 10-15%), and 99% for particulate. Since March 1992 a 5-MWe demonstration project, funded by the U.S. Department of Energy and by the Ohio Coal Development Office,... 

Organic nitrates are formed by radical coupling reactions between NO2 and either peroxyalkyl or peroxyacyl free radicals (see list of air free radicals in Box 1.). These nitrates redissociate both thermally andphotochemically, and thus represent temporary reservoirs for NOx, as follows from reaction (24)... 

Air. Compounds other than halogenated ones such as NOx and SO can likely cause damage to the ozone layer hence, they also should be included for investigation under this box. 

We have incorporated reactions (l)-(7) into a photochemical box model of the MBL [23]. The model treats chemical reactions in the gas phase and deliquesced sea-salt particles, as well as exchange between the two phases standard 03-NOx-HOx-S chemistry [23] is used. The sea-salt aerosol concentration was 3x10 m ... 

It is impossible to enumerate the many ions which can be determined with currently commercially available ion-selective electrodes because their number is continually increasing. Those cations or anions which are specifically and directly detected with these electrodes number about 30. In addition, there are those ions which, with the help of these 30, can be determined indirectly through chemical complexation, precipitation or biochemical reactions which serve to change the activity of the indicated ion in the solution equilibrium. Modified electrodes also make it possible to directly indicate gases such as NH3, CO2, NOx, SO2, etc., as well as organic compounds such as amino acids, amygdalin, cholesterol, urea, penicillin, etc. A current summary (Fig. 2) shows the periodic table with shaded boxes for elements which are directly indicated and boxes divided in half for elements which at present can be indicated only indirectly. The second row lists either the form in which the ion is specifically indicated or the chemical reaction with which the indirectly determined ion can be measured. No one has yet attempted to detect the remaining elements with the help of ion-selective electrodes as far as the author is aware (1973). 

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