Hydrocarbon fuel, sulfur composition

The MS analysis, whether it is done by El or FI, determines the hydrocarbon t5 e composition of the whole analyzed sample. In real practice very often it is necessary to estimate the composition of a certain distillation fraction without having to distill the sample (e.g. when the sample is available in a very small amoimt), or to prepare a blend that meets requirements in a specified boiling range. It may also be necessary to know sulfur distribution in order to choose the right cut point for a refinery stream to make a fuelblending component that will help maintain fuel spec in the particular situation at a specific refinery. All of these needs could be addressed by presenting the MS data distributed by boiling point. 

Fischer-Tropsch (FT) synthesis converts natural gas-, coal- and biomass-derived syngas into liquid hydrocarbon fuels which are totally free of sulfur- and nitrogen-containing compounds and have very low aromatic contents [1]. FT synthesis proceeds on cobalt metal sites, the overall niunber of cobalt metal sites on supported catalysts depends on both cobalt dispersion and reducibility. Decomposition of cobalt precursor is an important step in the catalyst preparation, which could significantly influence both cobalt dispersion and cobalt phase composition [2,3]. 

Products of Combustion For lean mixtures, the products of combustion (POC) of a sulfur-free fuel consist of carbon dioxide, water vapor, nitrogen, oxygen, and possible small amounts of carbon monoxide and unburned hydrocarbon species. Figure 27-12 shows the effect of fuel-air ratio on the flue gas composition resulting from the combustion of natural gas. In the case of solid and liquid fuels, the... 

Synthetic FT diesel fuels can have excellent autoignition characteristics. The FT diesel is composed of only straight-chain hydrocarbons and has no aromatics or sulfur. Reaction parameters are temperature, pressure and H/CO ratio. FT product composition is strongly influenced by catalyst composition the yield of paraffins is higher with cobalt catalytic ran and the yield of olefins and oxygenates is higher with ironcatalytic ran. 

Data on aerosol formation from irradiated automobile exhaust 5.193.23. 239 confirm the marked sensitivity to hydrocarbon type observed in individual hydrocarbon studies. Aerosol formation increases with the olefinic and aromatic fuel content. However, changes in mode of engine operation (acceleration, idle) and inorganic variables (sulfur dioxide, relative humidity) have a more pronounced effect on aerosol formation than change in fuel composition. ... 

Fuel oils are petroleum products that are used in many types of engines, lamps, heaters, furnaces, stoves, and as solvents. Fuel oils come from crude petroleum and are refined to meet specifications for each use. Fuel oils are mixtures of aliphatic (open chain and cyclic compounds that are similar to open chain compounds) and aromatic (benzene and compounds similar to benzene) petroleum hydrocarbons. In addition, they may contain small amounts of nitrogen, sulfur, and other elements as additives. The exact chemical composition (i.e., precise percentage of each constituent) of each of the fuel oils discussed in this profile may vary... 

The new specifications not only limit the concentration of sulfur to 0.05% but also specify that the fuel should have the combustion properties of a 10% or lower aromatics-containing fuel and have a minimum cetane number of 40. Fuels that have more than 10% aromatics are now able to meet these specifications through additives (22). However, as smoke emission standards become more restrictive, the aromatics content of diesel fuels may have to be lowered to a true value of 10% or less. A very thorough review of the consequences of this potential problem has recently been written by Stanislaus and Cooper, which covers in detail aromatic hydrocarbon hydroprocessing kinetics, thermodynamics, catalyst compositions, and mechanisms (109). There is little need to repeat the details of that report... 

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