Hydrogen mass balance

From hydrogen mass balance. b From elemental balance. 

The solution hydrogen concentration at any time t, [Hj], may be found by integration of the hydrogen mass balance ... 

DCL Axial dispersion Hydrogen mass balance Plug flow Partially backmixed Negligible Chemical (23) reaction... 

The preheater models are based on plug-flow behavior of both gas and the slurry phases, as the L/D ratios in preheater are usually large. Reliable estimates of the fluid properties such as viscosity and density, pressure drop across the preheater and heat transfer coefficient are needed for an optimum design of the preheater and, these have been recently reviewed by Shah (11). Parulekar et al. (17) have proposed a kinetic model for the preheater based on certain fast reactions taking place in the preheater whereas Nunez et al. (18) evaluated the hydrogen mass balance and a heat balance on the preheater. 

Turpin [46] recommends that hydrogen mass balances should be closed to less than 0.5% error This can be difficult without detailed verificahon of measured flow rates. We recommend that cahbrahon proceed even if the hydrogen balance cannot be closed. However, it may not be possible to perform a finely tuned cahbrahon as a result... 

To properly determine the hydrogen consumption in the hydrogen mass balance, the solubUity of the hydrogen in the liquid streams on Figure 12.7 is required. The mass-balance equations are based on the assumption that the gas-liquid equilibrium can be described by Henry s law as follows ... 

To estimate the current yield of magnesium alloys, the weight loss is determined indirectly over the volumetric measurement of the evolved hydrogen in the apparatus in Fig. 6-9 in Section 6.2.4. The mass balance for oxygen-free media follows from Eqs. (6-1) and (6-5a,b) or (6-14) ... 

To anticipate some of the results to be presented later, it is instructive to compute the equilibrium compn ofPETN at 1600°K. PETN is nearly oxygen-balanced and as will be shown later its Tfr- 1600°K. The empirical formula for PETN is CgHs On. Let X be the number of moles of C03 at equilibrium, and C, H, O the original gram atoms of carbon, hydrogen and oxygen respectively. Then from mass balance and Raoult s law... 

Pseudo-first order kinetics with respect to lactose implies (at constant hydrogen pressure) that the mass balance of lactose becomes... 

In any case, the time dependence of the hydrogen ion concentration at the interface should be obtainable from a mass-balance equation as... 

The amounts of exchange and addition were calculated from a hydrogen isotope mass balance of the coal products, donor solvent and gas phase hydrogen. The starting and product weights of the coal and hydrogen compositions of the coal and coal products are shown in Table IV. From the values in Table IV, the net amount of hydrogen added to the coal, H, is... 

The effect of hydrogen pressure in the reaction network and kinetics of quinoline hydrodenitrogenation has been matter of debate. Some controversial results and explanation were raised by the proposal of light hydrocarbons formation [78], The lack of observation of these hydrocarbons in previous experiments was explained by the low pressure employed and the deviations observed of the mass balances in these experiments were an evidence for the formation of lights HCs. The controversy is not clear yet and might be the subject for further investigations. 

In the present estimation, a continuous dehydrogenation reactor in which decalin is supplied to the catalyst at various feed rates without internal refluxing is assumed. Here all the condensable products and unconverted decalin were removed from the reactor to the condensation part (see Figure 13.22). Now, the stationary rates of hydrogen generation (VH), naphthalene formation (VN), and evaporation of unconverted decalin (VD) are defined as the magnitudes per area of the catalyst layer (mol/m2h). All these rates are expressed from mass balance as follows . 

In this chapter, we develop a mass balance model of the fractionation in reacting systems of the stable isotopes of hydrogen, carbon, oxygen, and sulfur. We then demonstrate application of the model by simulating the isotopic effects of the dolomitization reaction of calcite. 

In the following, the mass balance for substrate S and hydrogen in the liquid phase are written, considering that assumptions 1 to 4 hold. For a more illustrative view, mass balance is proposed with the concentrations as variables. In general, if the reaction stoichiometry is known, then the conversion number is used as the unified single variable. 

E. Matthijs, P. Gerike, H. Klotz, J.G.A. Kooijman, H.G. Karber and J. Waters, Removal and Mass Balance of the Cationic Fabric Softener Di(Hydrogenated)Tallow Dimethyl Ammonium Chloride in Activated Sludge Sewage Treatment Plants European Association of Surfactant Manufacturers (AIS/CESIO), Brussels, Belgium, 1992. 

The remaining equations are phase equilibria for ammonia (eq. K4) and water (eq. K5), mass balances for ammonia (eq. XV) and hydrogen sulfide (eq. XVII), the condition of bulk electroneutrality (eq. XIX), the mole balance in the vapor phase (eq. XX), and the assumption that, for the ammonia-rich systems considered exclusively, in the mass balance for the liquid hydrogen sulfide may be neglected. The system of eight equations can easily be solved ... 

The gas channels contain various gas species including reactants (i.e., oxygen and hydrogen), products (i.e., water), and possibly inerts (e.g., nitrogen and carbon dioxide). Almost every model assumes that, if liquid water exists in the gas channels, then it is either as droplets suspended in the gas flow or as a water film. In either case, the liquid water has no affect on the transport of the gases. The only way it may affect the gas species is through evaporation or condensation. The mass balance of each species is obtained from a mass conservation equation, eq 23, where evaporation/condensation are the only reactions considered. 

During the chemisorptions of Ru3(CO)i2 or Os3(CO)i2 on silica, the first step with the surface silanols was to produce a covalent bonding with the silica surface by oxidative addition of the silanol group to the metal-metal bond of the clusters. The nature of surface molecular species [=Si-0)(M3( x-H)(CO)io)j covalently linked to the silica surface (M = Ru, Os) was clearly defined and structurally characterized by a series of physical and chemical techniques, including mass balance taking into account the evolution of two molecules of CO and one molecule of hydrogen [27, 33, 35]. 

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