Hydrogen sensitivity analysis

Dougherty E P and Rabitz H 1980 Computational kinetics and sensitivity analysis of hydrogen-oxygen combustion J. Chem. Phys. 72 6571... 

In a silane-hydrogen discharge the feedstock gases SiHa and H2 take part in all the processes that occur. A large number of reactions have been proposed (see e.g. Kushner [190]). Nienhuis et al. [191] have performed a sensitivity analysis in their self-consistent fluid model, from which a minimum set of reactions have been extracted for a typical low-pressure RF discharge. Tables II and III list these reactions. They will be used in the plasma models described in subsequent sections. The review articles on silane chemistry by Perrin et al. [192] and on hydrogen by Phelps [193] and Tawara et al. [194] have been used. The electron collision data are compiled in Figure 13 [189]. 

Figure 17.12 shows some aspects of flame behavior that are revealed through sensitivity analysis (sensitivity analysis is discussed Section 15.5.4). For example, the maximum temperature is relatively insensitive to reaction rates, except very near the extinction point. At the extinction point, all sensitivities become unbounded because at the turning point the Jacobian of the system is singular. Near extinction, the hydrogen-atom concentration is... 

The kinetic and deactivation models were fitted by non-linear regression analysis against the experimental data using the Modest software, especially designed for the various tasks -simulations, parameter estimation, sensitivity analysis, optimal design of experiments, performance optimization - encountered in mathematical modelling [6], The main interest was to describe the epoxide conversion. The kinetic model could explain the data as can be seen in Fig. 1 and 2, which represent the data sets obtained at 70 °C and 75°C, respectively. The model could also explain the data for hydrogenated alkyltetrahydroanthraquinone. 

Sensitivity Analysis. The sensitivity of hydrogen price to the following variables was calculated raw materials cost, plant capital cost, stream factor, plant size, and by-product credits. 

M.D. Smooke, H. Rabitz, Y. Reuven and F.L. Dryer, Application of Sensitivity Analysis to Premixed Hydrogen-Air Flames, Comb. Sci. Tech. 59 (1988) 295-319. 

Complete a Monte Carlo sensitivity analysis of hydrogen storage and transportation costs. 

H2Sim compares the end-use cost of using hydrogen in either FCV or hybridized, direct hydrogen combustion vehicles in 2020 with today s internal combustion engine vehicles, hybrid, and electric vehicles. It also considers a 2020 FCV with onboard production of hydrogen. The default costs associated with each of the vehicles included in H2Sim were summarized in Table 8.1. This chapter focuses on the fuel and the total end-use costs associated with each vehicle based on fuel and vehicle cost sensitivity analysis. 

Figure 11.9 shows a static sensitivity analysis for a region with 100 fueling stations. The transport costs have been calculated to show the influence of the different parameters based on certain assumptions about transport distance and cars per FS. In the sensitivity analysis shown, the assumptions were 10 km dedicated distribution pipeline for each FS and 60 /MWh electricity costs for liquefaction. Onsite technologies are considered if transportation costs exceed 9 ct/kWh of hydrogen and if utilization is not too low (no fewer than 100 cars per FS). 

While the produced hydrogen can be sold as a versatile fuel on the market, it can also serve as a storage medium for electrical energy in the power system (see Sect. 2.3). As a consequence both kinds of use are in competition. A sensitivity analysis of electrolyzer costs and market prices of hydrogen is conducted. Based on this analysis, the main drivers for the potential of electrolytically produced hydrogen until 2050 are identified. 

Figure 2.4 shows the results of the sensitivity analysis concerning the variation of the market value of hydrogen and the investment costs of electrolyzers. The two diagrams at the top illustrate the situation in 2040, while the situation in 2050 is shown in the two diagrams at the bottom. Investment costs for the electrolysis system are assumed to amount to 1000 /kW in the diagrams on the left, whereas... 

An overview of the methods used previously in mechanism reduction is presented in Tomlin et al. (1997). The present work uses a combination of existing methods to produce a carbon monoxide-hydrogen oxidation scheme with fewer reactions and species variables, but which accurately reproduces the dynamics of the full scheme. Local concentration sensitivity analysis was used to identify necessary species from the full scheme, and a principle component analysis of the rate sensitivity matrix employed to identify redundant reactions. This was followed by application of the quasi-steady state approximation (QSSA) for the fast intermediate species, based on species lifetimes and quasi-steady state errors, and finally, the use of intrinsic low dimensional manifold (ILDM) methods to calculate the mechanisms underlying dimension and to verify the choice of QSSA species. The origin of the full mechanism and its relevance to existing experimental data is described first, followed by descriptions of the reduction methods used. The errors introduced by the reduction and approximation methods are also discussed. Finally, conclusions are drawn about the results, and suggestions made as to how further reductions in computer run times can be achieved. 

Dougherty, E. P. and Rabitz, H. (1980) Computational Kinetics and Sensitivity Analysis of Hydrogen - Oxygen Combustion , J.Chem.Phys. 72, 6571-6586. 

From the sensitivity analysis (Table 30.2), it appeared that the jacket temperatme Tjacket and hydrogen fraction xhi are the dominant influences. 

Zsely et al. (2003) performed numerical experiments to investigate this consequence of global similarity. Initially the concentration profiles were calculated for simulations of the adiabatic explosion of a stoichiometric hydrogen-air mixture using a nominal parameter set based on the values recommended by Baulch et al. (2005). Local sensitivity analysis was then used to select those parameters with the largest influence oti the simulated species concentrations based on a study of A-factors for the reaction rate coefficients. Five reactions were selected as dominating the influence on the calculated concentrations. At the next stage, the... 

Smooke, M.D., Rabitz, H Reuven, Y Dryer, F.L. Application of sensitivity analysis to premixed hydrogen-air flames. Combust. Sci. Technol. 59, 295-319 (1988)... 

H.D. Ng, Y. Ju, J.H. Lee, Assessment of detonation hazards in high-pressure hydrogen storage from chemical sensitivity analysis. Int. J. Hydrogen Energy 32(2), 93-99 (2007)... 

Batisse, R., Bailleul, M., 2007. Sensitivity Analysis of Clock Spring Repair to Hydrogen Gas-Effect on Burst Pressure. Report for Naturally, D0020-WP4-P-0., January. 

The major role of TOF-SARS and SARIS is as surface structure analysis teclmiques which are capable of probing the positions of all elements with an accuracy of <0.1 A. They are sensitive to short-range order, i.e. individual interatomic spacings that are <10 A. They provide a direct measure of the interatomic distances in the first and subsurface layers and a measure of surface periodicity in real space. One of its most important applications is the direct determination of hydrogen adsorption sites by recoiling spectrometry [12, 4T ]. Most other surface structure teclmiques do not detect hydrogen, with the possible exception of He atom scattering and vibrational spectroscopy. 

It is possible to use halogen-sensitive detectors in glc analysis of active hydrogen compounds by sdylating them with a halogenated sdylating agent, eg, CMDMS (9). 

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