Combustion method Complexation

The in situ combustion method of enhanced oil recovery through air injection (28,273,274) is a chemically complex process. There are three types of in situ combustion dry, reverse, and wet. In the first, air injection results in ignition of cmde oil and continued air injection moves the combustion front toward production wells. Temperatures can reach 300—650°C. Ahead of the combustion front is a 90—180°C steam 2one, the temperature of which depends on pressure in the oil reservoir. Zones of hot water, hydrocarbon gases, and finally oil propagate ahead of the steam 2one to the production well. 

The in situ combustion method of enhanced oil recovery through air injection (397,503,504) is an exceeding complex process chemically. However, because little work has been done on the effect of chemical additives to oil recovery efficiency, this process will not be discussed herein. 

Use of the combustion method in an atmosphere of air or oxygen to prepare complex metal oxides seems obvious. In the last three to four years, a variety of oxides have been prepared using nitrate mixtures with a fuel such as glycine or urea. It seems that almost any ternary or quaternary oxide can be prepared by this method. All the superconducting cuprates have been prepared by this method, although the resulting products in fine particulate form have to be heated to an appropriate high temperature in a desired atmosphere to obtain the final cuprate [18], Table 2 lists typical materials prepared by the combustion method. 

Rare earth silicates exhibit potential applications as stable luminescent materials for phosphors, scintillators, and detectors. Silica and silicon substrates are frequently used for thin films fabrication, and their nanostructures including monodisperse sphere, NWs are also reliable templates and substrates. However, the composition, structure, and phase of rare earth silicates are rather complex, for example, there are many phases like silicate R2SiOs, disilicate R2Si207 (A-type, tetragonal), hexagonal Rx(Si04)602 oxyapatite, etc. The controlled synthesis of single-phase rare earth silicate nanomateriais can only be reached with precisely controlled experimental conditions. A number of heat treatment based routes, such as solid state reaction of rare earth oxides with silica/silicon substrate, sol-gel methods, and combustion method, as well as physical routes like pulsed laser ablation, have been applied to prepare various rare earth silicate powders and films. The optical properties of rare earth silicate nanocrystalline films and powders have been studied. 

Shan, W., Feng, Z., Li, Z., Zhang, J., Shen, W., and Li, C. Oxidative steam reforming of methanol on CeogCuo.iOy catalysts prepared by deposition-precipitation, coprecipitation, and complexation-combustion methods. Journal of Catalysis, 2004, 228 (1), 206. 

Since the average concentration of organic C, estimated by the dry combustion method, in the water layer from 0 to 100 m equals about 1.8 mg T and at depths of more than 2000 m from 1.2 to 1.4 mg T for three oceans (Skopintsev et al., 1976), the fraction of carbon from identified labile organic compounds in the deep oceanic waters will be less than 10%. The remaining 90% are probably made up of refractory (stable) organic complexes — the water humus. 

The glycine nitrate process is one of a general class of combustion methods for the preparation of ceramic powders. A highly viscous mass formed by evaporation of a solution of metal nitrates and glycine is ignited to produce the powder (101). Glycine, an amino acid, forms complexes with the metal ions in solution which... 

This combination of anaerobic and aerobic environment adds some complexity to the process but enables larger loads to be purified such as shown in Figure 2-23. One of the primary effluent gasses is trimethylamine. This tertiary amine has the very characteristic odor of rotten fish. Combustion methods can be used to treat this waste but these will produce NOj, effluents unless very special measures are employed in waste treatment. An alternative wet chemical processes was developed (Bohrer, 1999). The liquid solution waste can also be oxidized to produce a non-odoriferous solid using hydrogen peroxide. This alternative waste treatment process keeps the nitrogen fixed, reducing the atmospheric... 

Since the discovery that fullerenes form in supersonic molecular beams (7), many techniques (2-9) have been used to produce fullerenes. Out of these many techniques, carbon-arc and combustion methods have been used for commercial production of fullerenes. In the carbon-arc method, yields of 5% to 8% are common, and yields as high as 40% have been reported (10). It has been a puzzle for some time how a molecule as complex as fiillerene can be formed so readily. Various formation mechanisms have been proposed (11-14). In particular the isolated pentagon rule (IPR) appears to explain many of the experimental observations. 

Wang KJ, Zhong P, Zhu JJ. (2009). Preparation of Highly Active and Stable Perovskite-like Catalyst by Combustion Method Effect of Complex. Catal Lett. 131, 672-5. 

The formation of such materials may be monitored by several techniques. One of the most useful methods is and C-nmr spectroscopy where stable complexes in solution may give rise to characteristic shifts of signals relative to the uncomplexed species (43). Solution nmr spectroscopy has also been used to detect the presence of soHd inclusion compound (after dissolution) and to determine composition (host guest ratio) of the material. Infrared spectroscopy (126) and combustion analysis are further methods to study inclusion formation. For general screening purposes of soHd inclusion stmctures, the x-ray powder diffraction method is suitable (123). However, if detailed stmctures are requited, the single crystal x-ray diffraction method (127) has to be used. 

In modem Hquid-fuel combustion equipment the fuel is usually injected into a high velocity turbulent gas flow. Consequently, the complex turbulent flow and spray stmcture make the analysis of heterogeneous flows difficult and a detailed analysis requires the use of numerical methods (9). 

Chemical Volume Reduction Incineration has been the method commonly used to reduce the volume of wastes chemically. One of the most attractive features of the incineration process is that it can be used to reduce the original volume of combustible sohd wastes by 80 to 90 percent. The technology of incineration has advanced since 1960 with many mass burn facihties now have two or more combustors with capacities of 1000 tons per day of refuse per unit. However, regiila-tions of metal and dioxin emissions have resulted in higher costs and operating complexity. 

This method involves very simple and inexpensive equipment that could be set up m any laboratory [9, 10] The equipment consists of a 250-mL beaker (used as an external half-cell), two platinum foil electrodes, a glass tube with asbestos fiber sealed m the bottom (used as an internal half-cell), a microburet, a stirrer, and a portable potentiometer The asbestos fiber may be substituted with a membrane This method has been used to determine the fluoride ion concentration in many binary and complex fluondes and has been applied to unbuffered solutions from Willard-Winter distillation, to lon-exchange eluant, and to pyrohydrolysis distil lates obtained from oxygen-flask or tube combustions The solution concentrations range from 0 1 to 5 X 10 M This method is based on complexing by fluonde ions of one of the oxidation states of the redox couple, and the potential difference measured is that between the two half-cells Initially, each cell contains the same ratio of cerium(IV) and cerium(tll) ions... 

Authenticity evaluation has recently received increased attention in a number of industries. The complex mixtures involved often require very high resolution analyses and, in the case of determining the authenticity of natural products, very accurate determination of enantiomeric purity. Juchelka et al. have described a method for the authenticity determination of natural products which uses a combination of enantioselective multidimensional gas chromatography with isotope ratio mass spectrometry (28). In isotope ratio mass spectrometry, combustion analysis is combined with mass spectrometry, and the ratio of the analyte is measured versus a... 

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