Hydrocarbons as fuels

HO oxidation of CO is much faster than the reaction with methane, resulting in a mean CO lifetime of about two months, but considerably slower than reaction with the majority of the nonmethane hydrocarbons. Table I gives representative removal rates for a number of atmospheric organic compounds their atmospheric lifetimes are the reciprocals of these removal rates (see Equation E4, below). The reaction sequence R31, R13, R14, R15 constitutes one of many tropospheric chain reactions that use CO or hydrocarbons as fuel in the production of tropospheric ozone. These four reactions (if not diverted through other pathways) produce the net reaction... 

The hydrocarbons from fossil fuels can be use to make products of far greater value than gasoline and fuel oil. These products affect every facet of modem life. They include things as diverse as drugs, paint, plastics, rubber, cloth, and lubricants. These alternate uses provide a strong motivation for terminating the use of hydrocarbons as fuels and preserving them for beneficial future uses. 

The result of our profligate burning of valuable hydrocarbons will be the escalation of their price. The high price will effectively deprive future generations of their use and the large number of valuable materials derived from them. To preserve these unique resources for future high value uses we should immediately make plans to develop other sources of energy and terminate the use of hydrocarbons as fuels. We should also maximize our recycle of these materials. 

It is this type of reaction that accounts for the wide use of hydrocarbons as fuels. 

In contrast to stationary applications, portable applications require frequent start and stop procedures. Therefore for SOFC, a robust cell design and adapted electrode-electrolyte assemblies are an important issue. Frequent thermal cycles between room temperature and an operation temperature of about 600-800 °C pose challenges to the layered system consisting of solid anode, ceranfic electrolyte and solid cathode with respect to thermal and mechanical stability. For several years, different approaches to developing tubular nficro SOFC have been undertaken but did not lead to a commercial product yet. As SOFC can be operated with pure hydrogen, reformate and hydrocarbons as fuel as well - the latter option means direct internal reforming at the anode catalyst — various investigations focused on reduced operation temperature and a parallel conversion of fuels [21]. 

The anode is exposed to hydrogen or hydrocarbons as fuel. It should be a mixed conductor with dominantly electronic conducting to allow the transportation of the electrons produced as a result of the chemical reaction at the anode surface. The electrode composition, powder particle size, and the manufacturing method are important parameters that affect the electronic and ionic conductivity and the activity for the electrochemical reactions. The electrical resistance is composed... 

Grain growth and sintering of Ni during operation and susceptibility of Ni towards sulfur poisoning and carbon deposition constrain the application of Ni-based cermet anode in certain applications. Generally, to use hydrocarbons as fuel in Ni cermet-based anode, a considerable amount of... 

Geneva presented a thin film fuel cell concept in a 1962 patent [12]. Also in 1962, Sandstede from the Battelle Institute in Frankfurt gave the first report on the use of hydrocarbons as fuel in solid oxide cells [13]. At about the same time, fuel cell work was started in France by Kleitz [14], and in Britain, a patent was filed in 1963 [15] to form fuel cells by depositing layers on a porous metallic carrier. In Japan, Takahashi published in 1964 his first results obtained on fuel cells with solid oxide electrolytes [16]. 

Working temperature of solid oxide fuel cells (SOFC) varies in the range of 600-900 °C. A unique feature of these cells is their ability to utilize methane or other hydrocarbons as fuels. In combination with high power density (about 1 W cm ), this makes SOFCs a very attractive power source for residential applications. 

Hydrocarbons—compounds that contain only carbon and hydrogen—are the simplest organic compounds. However, because of the uniqueness of carbon, many different kinds of hydrocarbons exist. We use hydrocarbons as fuels. Candle wax, oil, gasoline, LP gas, and natural gas are all composed of hydrocarbons. Hydrocarbons are also the starting materials in the synthesis of many different consumer products including fabrics, soaps, dyes, cosmetics, drugs, plastic, and rubber. 

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