Fuel sweetening additives

Compounds such as H2S and mercaptans are not commonly found in finished fuels. However, the possibility of carryover of these compounds into finished fuels can occur if fuel processed from high-sulfur crude oil is not properly stripped, caustic washed, or sweetened through refining. If H2S and mercaptans are found in finished fuel, they can still be removed by the addition of chemical sweetening additives. 

Amine compounds including primary amines and amine-aldehyde condensation products are commonly utilized as fuel sweetening applications. Primary amines will react with H2S to form amine sulfide compounds. These products are somewhat unstable and may tend to solubilize into water. 

Amine-aldehyde condensation compounds are believed to react with H2S to form more complex carbon-sulfur bonded products. 

Mercaptans are more difficult to remove from fuel than H2S. Amine hydroxide compounds have been shown effective at removing mercaptans from fuel. The reaction products are typically not fuel soluble and must be separated before the fuel can be used. 

The most common compound used to improve the cetane number of distillate fuel is 2-ethylhexyl nitrate, an isooctyl nitrate. Dibutyl peroxide, certain glycols and other nitroparaffins are also effective at improving the cetane number of diesel fuel, but their acceptance is not as widespread as isooctyl nitrate. 

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Use fuel sweetening additives which chemically react with corroding agent use sweetener at treat rate of one to two times the concentration of the corroding agent... 

Some chemical additives such as corrosion inhibitors, wax crystal modifiers, detergents, and demulsifiers provide performance which is difficult to duplicate through refining without adversely affecting some other fuel property. Other additives such as metal chelators, fuel sweeteners, biocides, lubricity improvers, foam control agents and combustion enhancers can also be used to solve fuel performance problems. 

The gasoline specification ASTM D-4814 states that gasoline must pass the ASTM D-130 test with a corrosion rating of lb or better before it can be sold. The addition of sweetening additives to fuels which do not meet this specification can often improve the corrosion rating. Additive treat rates of 25 to 1000 ppm are common. The following test conditions are recommended for various fuels and oils ... 

In addition to using a phosphate buffer solution of pH 7, solutions of different pH values can often be evaluated. The use of pH 4 and pH 10 buffer solutions are typically requested. The use of pH 4 buffer simulates acid carryover into fuel from acid washing, acid extraction, or acid catalysis. The use of pH 10 buffer simulates caustic washing or caustic carryover from fuel sweetening and neutralization processes. 

Uses Monomer for industrial and automotive clear coatings, dye additives intermediate for water treatment and oil field chems. stabilizer for fuel oils sweetening agent for various hydrocarbon oils acrylic resin modifier for automotive industry rubber modifier and stabilizer retention aid for paper mfg. water clarifier for o/w emulsions Properties Clear liq. m.w. 185.27 sp.gr. 0.922 (20/20 C) f.p. < -60 C b.p. 114 C (30 mm) flash pt. 77 C... 

Obtained duties from HYSYS were implemented in a developed excel sheet aiming to calculate the flow rate of CO2 (kg/hr) produced from burning fuel (for furnace and for steam generation) in addition to the flow rate of CO2 emitted from the acid gas stream at the top of the regenerator in Acid Gas Sweetening unit. Fig.2 shows the results of all scenarios for units with Carbon Footprint. 

Methanol is produced in the body by the action of the digestive system on a wide range of products, particularly natural products such as fruit and also on some man-made additives such as the sweeteners used in diet drinks. It is interesting to note that the body decomposes the methanol, in the liver, to carbon dioxide in exactly the same step-wise fashion as the fuel cell. The steps are methanol to formaldehyde, formaldehyde to formic acid, and formic acid to carbon dioxide. The problem is not the methanol per se, but the formic acid formed in the breakdown process. This acidifies the blood and causes fatal problems if allowed to reach excess levels. 

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