Hydrocarbon combustion, problems

It appears that a permanent solution to the world energy problem, dramatic reduction of biospheric hydrocarbon combustion pollution, and eliminating the need for nuclear power plants (whose nuclear component is used only as a heater) could be readily accomplished by the scientific community [18]. However, to solve the energy problem, we must (1) update the century-old false notions in electrodynamic theory of how an electrical circuit is powered and (2) correct the classical electrodynamics model for numerous foundations flaws. 

At this time of an escalating world oil crisis and particularly a shortage of refining facilities, a very rapid and permanent solution to the oil crisis and the rapidly increasing demand for electricity—and also much of the problem of the present pollution of the biosphere by combustion byproducts, and of the present global warming enhancement by the emitted CO2 from the hydrocarbon combustion—can be provided cheaply, widely, and expeditiously. 

You have seen, written, and balanced several types of reaction equations so far in this textbook. In the following sample problem, you will learn an easy way to write and balance hydrocarbon combustion equations. 

Reactions in the Gas Phase VOCs are major air pollutants, and catalytic combustion is one of the most important technologies for eliminating low concentrations of VOCs in effluent systems [64] Platinum metal is the most active catalyst for hydrocarbon combustion and is widely used supported on AI2O3 and other oxides. It is important for this combustion to take place at low temperatures. However, the water vapor produced during combustion under these conditions can be adsorbed on the oxide support due to its hydrophilicity, which can negatively affect the catalytic activity of the metal. This activity can also be affected by humidity in the feeding stream. Hydrophobicity of carbon materials could overcome this problem, and activated carbons have been proposed as supports in VOC combustion [65,66]. 

Environmental Problems Associated with Hydrocarbon Combustion... 

Because we work on such a small scale, we can be somewhat venturesome in making measurements. We want to describe briefly some measurements of species that have not been reported in explosives by any other method, namely carbon clusters. The problem of soot formation is certainly a long standing one in any hydrocarbon combustion study as well as in modeling detonations. For example, neglecting the heat release from soot formation in... 

If the natural gas produced is used locally as a fuel for combustion engines operating compressors or power-generating turbines, the presence of higher hydrocarbons can cause combustion problems or even accelerate aging of the engines. 

Computer experiments particularly use quantum chemical approaches that provide accurate result with intense computational cost. Classical or semiempirical methods on the other hand are able to simulate thousands or up to millions of atoms of a system with pairwise Lennard-Jones (LJ)-type potentials [104-107]. Thus, LJ-type potentials are very accurate for inert gas systems [108], whereas they are unable to describe reactions or they do so by predetermined reactive sites within the molecules of the reactive system [109]. van Duin and coworkers [109-115] developed bond-order-dependent reactive force field technique is called ReaxFF as a solution to the aforementioned problems. Therefore, ReaxFF force field is intended to simulate reactions. They are successfully implemented to study hydrocarbon combustion [112,115,116] that is based on C-H-0 combustion parameters, fuel cell [110,111], metal oxides [117-122], proteins [123,124], phosphates [125,126], and catalyst surface reactions and nanotubes [110-113] based on ReaxFF water parameters [127]. Bond order is the number of chemical bonds between a pair of atoms that depends only on the number and relative positions of other atoms that they interact with [127]. Parameterization of ReaxFFs is achieved using experimental and quantum mechanical data. Therefore, ReaxFF calculations are fairly accurate and robust. The total energy of the molecule is calculated as the combination of bonded and nonbonded interaction energies. 

Perhaps the most time-consuming part of the detailed transport property computation is the solution of Eqs. (3.25a), which involves the inversion of approximately a 3AT x 3AT matrix. The solution of this set of equations is necessary for the evaluation of the thermal conductivity and the thermal diffusion coefficients in the mixture. However, in hydrocarbon combustion systems N may be 20 or more, and if all these components are included the cost of the calculation becomes prohibitive. One approach to overcoming the problem is to exclude from this part of the calculation minor reaction intermediates which are unlikely to contribute appreciably either to the thermal conductivity or to thermal diffusion. This reduces the mixture to seven or eight effective components which are normally H, N2 or Ar, O2, H2, CO, CO2, H2O, and the initial hydrocarbon. 

In summary, the bad features of partial combustion processes are the cost of oxygen and the dilution of the cracked gases with combustion products. Flame stability is always a potential problem. These features are more than offset by the inherent simplicity of the operation, which is the reason that partial combustion is the predominant process for manufacturing acetylene from hydrocarbons. 

The problems with the combustion reaction occur because the process also produces many other products, most of which are termed air pollutants. These can be carbon monoxide, carbon dioxide, oxides of sulfur, oxides of nitrogen, smoke, fly ash, metals, metal oxides, metal salts, aldehydes, ketones, acids, polynuclear hydrocarbons, and many others. Only in the past few decades have combustion engineers become concerned about... 

The most widespread and persistent urban pollution problem is ozone. The causes of this and the lesser problem of CO and PMjq pollution in our urban areas are largely due to the diversity and number of urban air pollution sources. One component of urban smog, hydrocarbons, comes from automobile emissions, petroleum refineries, chemical plants, dry cleaners, gasoline stations, house painting, and printing shops. Another key component, nitrogen oxides, comes from the combustion of fuel for transportation, utilities, and industries. 

Examples of the need for multimedia models are found in contemporary problem areas. Polynuclear aromatic hydrocarbons and metals are emitted into the atmosphere as trace impurities with the products of coal combustion. The organics have low vapor pressure and partially condense on emitted particulates in a stack plume. The particulates are transferred to the soil by dry deposition, rainout or washout. The metals manifest... 

The two most important environmental hazards faced by humankind today are air pollution and global warming. Both have a direct link with our current overdependence on fossil fuels. Pollutants produced from combustion of hydrocarbons now cause even more health problems due to the urbanization of world population. The net increase in environmental carbon dioxide from combustion is a suspect cause for global warming, which is endangering the Earth—the only known place to support human life. In addition, the import of expensive hydrocarbon fuel has become a heavy burden on many countries, causing political and economic unrest. 

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