Impurities in, Fuel

Trace Impurities in Fuels by Isotope Dilution Mass Spectrometry... 

Furthermore, slurry-coated cermet anodes have various long-term stability problems, particularly due to the fine particle size of the metallic component.It has also been reported that the tolerance for impurities in fuels is very limited. High levels (100 ppm) of H S may cause significant irreversible performance loss due to anode poisoning. 

There are other impurities in fuels too, but sulphur has always been seen as most characteristic of the air pollution problems of cities. 

Although air pollution and smoke have traditionally been closely linked, there were always those who thought there was more to air pollution than just smoke. We can now see how impurities in fuel give rise to further pollutants. In addition, the fact that we burn fuels, not in 02, but in air has important consequences. We have learnt that air is a mixture of 02 and N2. At high temperature, in a flame, molecules in air may fragment, and even the relatively inert N2 molecule can undergo reaction ... 

Table 6.6 Common impurities in fuel for various fuel cells [4]...

Matsuda Y (2009) Accumulation behavior of impurities in fuel cell hydrogen circulation system, 2009 fuel cell seminar, 16-11-2009 Courtesy associates, Washington... 

Another source of carbon oxide impurities in fuel cells is carbon corrosion. Carbon, which is employed as an electrode support in both anode and cathode, can undergo oxidation reactions and produce CO [15-20] ... 

The average lifetime of a vehicle is about 10 to 12 years, but the actual operating time is only in the order of 3000 to 5000 hours. Therefore, the fuel cells for automotive applications are expected to have a similar lifetime. Limited laboratory testing to date has confirmed that the PEM fuel cells can meet these expectations, although the effect of real-life conditions (numerous start-ups and shutdowns, impurities in fuel and in air) on the fuel cell and fuel cell system components life has yet to be determined. 

PEMFC contamination can also adversely impact membrane performance and life. The common impurities in fuel cell include anions, cations, CO, HjS, NH3, SO , NO, and volatile organic compounds. - Cationic impurities, including alkaline metals and ammonium, can infiltrate the membrane, considerably reducing performance. Metal ions, such as Fe + and Cu, can catalyze the radical formation reactions, strongly accelerating the chemical degradation of membranes in a PEMFC. Stainless steel is unsuitable as a material for end plates in PEMFCs. ... 

Natural gas requires no fuel treatment however, low-Btu gas, espeeially if derived from various coal gasification processes, requires various types of cleaners for use in a gas turbine. These cycles can get very complex as indicated by a typical system, which utilizes a steam bottoming cycle to achieve high efficiency. Vaporized fuel oil gas is already cleansed of its impurities in the vaporization process. 

The centrifugal fuel-cleaning process consists of mixing 5-10% water with the oil plus an emulsion breaker to aid the separation of water and oil. Then a mixer dispenses the wash water into the oil stream to aid the impurities in forming a water solution. The centrifuges then separate this water from the... 

The gas plant products, namely fuel gas, Cfs, 4, and gasoline, contain sulfur compounds that require treatment. Impurities in the gas plant products are acidic in nature. Examples include hydrogen sulfide (HjS), carbon dioxide (COj), mercaptan (R-SH), phenol (ArOH), and naphthenic acids (R-COOH). Carbonyl and elemental sulfur may also be present in the above streams. These compounds are acidic. 

Or S W. Basic sediment and water. The paraffin, sediments, and salt water impurities in crude and oil fuels that need to be removed prior to further processing or use. 

L.26 Sulfur is an undesirable impurity in coal and petroleum fuels. The mass percentage of sulfur in a fuel can be determined by burning the fuel in oxygen and dissolving the SO, produced in water to form aqueous sulfuric acid. In one experiment, 8.54 g of a fuel was burned, and the resulting sulfuric acid was titrated with 17.54 mL of 0.100 m NaOH(aq). (a) Determine the amount (in moles) of H2S04 that was produced, (b) What is the mass percentage of sulfur in the fuel ... 

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