Sulfur in petroleum

Table 5-3. Comparison of Speed, Accuracy, and Cost for Determination of Sulfur in Petroleum Products...

Oxidative microcoulometry has become a widely accepted technique for the determination of low concentrations of sulfur in petroleum and petroleum products (ASTM D3120). The method involves combustion of the sample in an oxygen-rich atmosphere followed by microcoulometric generation of a triiodide ion to consume the resulting sulfur dioxide. It is intended to distinguish the technique from reductive microcoulometry, which converts sulfur in the sample to hydrogen sulflde that is titrated with coulometrically generated silver ion. 

The paper presents a general picture both on a geographical and on a product basis of the distribution of sulfur in petroleum. Early processes for desulfurization and sweetening are briefly reviewed and process developments are discussed on the basis of a simple division of petroleum products into gases, light distillates, and middle distillates and fuel oils. Future needs of the industry are discussed, and the ways in which research is likely to be applied. 

Waldo, G. S., Mullins, O. C., Penner-Hahn, J. E., and Cramer, S. E. (1991b). Determination of the chemical environment of sulfur in petroleum asphaltenes by x-ray absorption spectroscopy. Fuel 70,549-559. 

ORR SINNINGHE DAMSTE Geochemistry of Sulfur in Petroleum Systems 3... 

Sulfur in Petroleum Products by Wavelenght Dispersive X-Ray Fluorescent Spectrometiy... 

D 4294 Sulfur in Petroleum Products by Energy-Dispersive X-Ray Fluorescence Spectroscopy... 

Reference to Table 4.1 indicates that olefins can be determined by the electrochemical generation in situ of halogens. Bromine is effective for both olefins and sulfur compounds and is the basis for an automatic coulometric titrator for continuous analysis of petroleum streams.17 The basic principle of this instrument is a potentiometric sensing system that monitors bromine concentration in a continuously introduced sample stream. The bromine in the solution reacts with the sample components and causes a decrease in the concentration of bromine. When this decrease is sensed by the potentiometric detection electrodes, the electrolysis current producing bromine adjusts itself to maintain the bromine concentration. Because the sample is introduced at a constant rate, the electrolysis current becomes directly proportional to the concentration of the sample component. Thus, the instrument records the electrolysis current as concentration of sample component and provides a continuous monitor for olefins or sulfur in petroleum streams. 

Sulfur. The analytical methods used for determination of sulfur in petroleum oils involve combustion under oxygen pressure in a bomb, or burning the oil in a wick lamp and absorbing the sulfur oxides in hydrogen peroxide. Conventional gravimetric or volumetric methods are then employed to determine the sulfate. A turbidimetric method is recommended in the case of low sulfur contents. 

The oxides of sulfur create global pollution problems because they have longer lifetimes in the atmosphere than the oxides of nitrogen. Some of the SO2 and SO3 in the air originates from biological processes and from volcanoes, but much comes from the oxidation of sulfur in petroleum and in coal burned for fuel. If the sulfur is not removed from the fuel or the exhaust gas, SO2 enters the atmosphere as a stable but reactive pollutant. Further oxidation by radicals leads to sulfur trioxide ... 

Prior to the formation of the API Project 48, the Bureau of Mines initiated research on the problem of sulfur in petroleum. For this reason the Advisory Council of Project 48 after its formation elected the Bureau of Mines to carry out a portion of its program because such an arrangement was to their mutual interest and would eliminate duplication of work. There are some phases of the Bureau s work on sulfur in petroleum that API Project 48 does not support. Some of the publications on this type of work and on Bureau of Mines work on sulfur in petroleum before the estabhshment of Project 48 are as follows (2, 20, Jfi, 49, 50, 112, 124, 1 4, IM- Other Bureau of Mines... 

Petroleum Companies. Some of the major petroleum companies are carrying on extensive research programs on problems associated with the presence of sulfur in petroleum and as a product of this research some information on the availability of sulfur compounds derivable from petroleum has been obtained. While much of this information is of necessity confidential, some portion of it is eventually presented at American Chemical Society meetings or is published in the chemical literature. Although no attempt can be made to name all the companies carrying on work of this sort, there have been recent contributions by research workers from Phillips Petroleum Company, Standard Oil Development Company, Anglo-Iranian Oil Company, Union Oil Company, and Standard Oil Company (Indiana). 

Sulfur in Petroleum Boiling Points, Freezing Points, Densities, and Refractive Indices of Some Sulfur Compounds. 

Distribution of sulfur in petroleum. Review of desulfurization and sweetening processes.)... 

A considerable number of tests are available to estimate the sulfur in petroleum or to study its effect on various products. Hydrogen sulfide dis-... 

The lamp combustion method (ASTM D-1266, IP 107) and the Wickbold combustion method (IP 243) are used for the determination of sulfur in petroleum and as trace quantities of total sulfur in petroleum products and are related to various other methods (ASTM D-2384, ASTM D-2784, ASTM D-2785, ASTM D-4045)... 

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