Sulfur in fuel

Plant operators should aim at using fuel with less than 0.5% sulfur (or an emissions level corresponding to 0.5% sulfur in fuel). High-sulfur fuels should be directed to units equipped with SO, controls. Fuel blending is another option. A sulfur recovery system that achieves at least 97% (but preferably... 

There are well over 100 gaseous and aqueous phase reactions that can lead to acid formation and more than fifty oxidizing agents and catalysts may be involved. However, in the simplest terms sulfur in fuels is oxidized to SO2, and SO2 in the atmosphere is further oxidized and hydrolyzed to sulfuric acid. Most nitric acid is formed by the fixation of atmospheric nitrogen gas (N2) to NO. (NO and NO2) during high temperature combustion, followed by further oxidation and hydrolysis that produces nitric acid in the atmosphere. These materials can be dry-... 

Although rarely found in finished fuels, elemental sulfur could appear as a reaction product in fuels exposed to oxygen, rust or acids. The source of elemental sulfur in fuel is usually hydrogen sulfide gas. Reactions which can liberate sulfur can proceed... 

The degree of conversion to sulfur trioxide is influenced by three factors 1) the amount of sulfur in fuel, b) the amount of excess air used in combustion and, c) the presence of oxidation catalysts. Figure 1 illustrates SO3 formation for coal and oil as a function of excess air used in combustion. More pronounced... 

Cooperative research has also become increasingly important—notably through the establishment, just 25 years ago, of the API program of fundamental research. Much joint work has also been done with other industries. The automobile industry has joined in various important studies on the effect of octane number, vapor pressure, and sulfur in fuels, and on the increasingly important subject of additive-containing lubricating oils. The airplane industry and the airplane users—particularly the Armed Forces—have likewise cooperated, and have profited greatly by the results. 

For these reasons, the burden of environmental protection is falling on the manufacturers of the fuels to produce products that will have minimal impact on the environment, and this translates to very low levels of sulfur in fuels. So-called deep refining of petroleum products is thus required, although the extent of this refining may vary, depending on the type of fuel and its content of contaminants. 

J.E. Johnsson and P. Glarborg. Sulfur Chemistry in Combustion I - Sulfur in Fuels and Combustion Chemistry. Kluwer Academic Publishers, Amsterdam, 2000. 

The deposition of molten Na.SOj in gas turbines is believed to be related to the reaction between the residual sulfur in fuel and sodium, which may... 

S.41 of gypsum is formed per I of sulfur in fuels in flue gas desulfui ization... 

Sorbent Fuel Description Sulfur in Fuel (ppmw) Adsorption Conditions Breakthrough Capacity (mg-S/g) Saturated Capacity (mg-S/g) Affiliation Reference... 

Sorbent Fuel Description Sulfur in Fuel (ppmw) Adsorption Conditions... 

In many industrial areas, emissions of gaseous oxides of sulfur (SOx), especially sulfur dioxide (S02), also rival natural sulfur gas emissions from volcanoes, wetlands, and oceans. SOx are produced from the oxidation of sulfur in fuels, especially coals and residual oils, and are responsible in large part for acid rain (Section 4.6.3). In fuels, sulfur typically occurs either in organic compounds (organic S) or as pyrite (FeS2). SOx also are formed from the refining of the ores of the many metals that occur in the form of metal sulfides [e.g., copper (Cu), lead (Pb), and nickel (Ni)]. 

Although some sulfuric acid is emitted directly by fuel-burning equipment, most of the sulfur in fuel is oxidized to and emitted as sulfur dioxide (S02). Sulfur dioxide contains sulfur in the ( + IV) oxidation state and dissolves in water to form sulfurous acid (H2S03), a relatively weak acid. In the presence of hydroxyl radicals in the atmosphere, sulfur dioxide is oxidized to sulfur trioxide (S03), which contains sulfur in the (+VI) oxidation state. Sulfur trioxide reacts with water to form H2S04, a strong acid. 

It might be specifically emphasized that Thai lignite is a highly sulfurous fuel containing 1.7-3.0% (in some samples up to 7.0%) of sulfur in fuel mass as-received. The share of SO2 emission from the power generation sector accounts for 60-65%, the predominant part of which belongs to the Mae Moh Power Plant. The contribution shares of other pollutants (NOx, CO2, CO) formed in utility and industrial boilers of power and other sectors are much lower (Chungpaibulpatana et al, 1997). 

Op, Np, Sp = content of oxygen, nitrogen, and sulfur in fuel, % by volume,... 

Because of such poor quality of data, the U.S. EPA did not include D 4294 as one of the preferred methods for determining sulfur in fuels of the future. With active help fi-om instrument vendors, ASTM is looking into the possibility of improving the accuracy and the precision of new technology EDXRF methods. Several such initiatives are underway. 

TABLE 9—Analysis for low levels of sulfur in fuel products. 

Given the increasing importance of precisely measuring lower and lower quantities of sulfur in fuels of the future, it is not surprising that a number of organizations are working to develop better methods for such analyses. Some of these methods, which have been presented for ASTM review, include ... 

Low-Level Sulfur In Fuel Determination Using Monochromatic WD XRF—ASTM D 7039-04... 

ABSTRACT Current and upcoming regulations worldwide require maximum concentrations of sulfur in fuels to be in the range 10-50 mg/kg. This paper describes a new on-line analyzer for ultra low sulfur, the first to etrqtloy Pyro-electrochemical technology, which is significantly sinyler than other pyrolysis methods such as Pyro-microcoulometry and Pyro-UV fluorescence. 

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