Distillation products, sulfur content

The feed and products were characterized in order to determine the total sulfur content and distillation curve. Sulfur content in the feedstock and products was determined with HORIBA equipment (SLFA-2100) by using the standard ASTM D-4294 method. The variation coefficient of the analysis with this instrument is 0.006%. 

Assuming that demand for petroleum continues to increase at a rate of 1.2% per annum to 2010,37 and that all gasoline and diesel produced by U.S. refineries will have a sulfur content of less than 30 ppm, desulfurization of gasoline and diesel to these low levels will require extensive hydrotreating of both catalytic cracker feed and product of distillate. 

Liberated gasses are drawn off at the top of the tower with the naptha. The gas is recovered to manufacture refrigerated liquefied petroleum gas (LPG). The naptha is condensed at a temperature of about 52 °C (125 °F). Part of the condensed naptha is normally returned to the top of the tower. The naptha product stream is split into light naptha for gasoline blending and heavy naptha for further reforming. Inside the tower, kerosene is withdrawn at a temperature of about 149 °C (300 °F). Diesel is withdrawn at a temperature of 260 °C (500 °F). These middle distillates are usually brought up to specification with respect to sulfur content with hydrodesulfurization. The heavy oil... 

Characterization of LNAPL in pools underlying the site consisted of collecting and analyzing over 120 LNAPL samples. LNAPL product samples were distilled and analyzed to determine API gravity, lead, and sulfur content. Boiling point and percent recovery data were used to generate distillation curves. 

Light Distillates (6). The main products in this category are gasolines and kerosenes. As far as sulfur is concerned in these products, in most countries there is now a fair agreement with regard to quality requirements. Both products are expected to have no objectionable smell, to pass a corrosion test, and to have sulfur content below 0.25% by weight. 

It is in the field of middle distillates and fuel oils that sulfur may confront some refiners with major problems that will grow as the production of higher sulfur crudes increases. It may be worth while to consider in some detail the case of high speed Diesel oil, for which discussion about sulfur content is controversial. Curiously enough it is in the United States, where low-sulfur material has been in relatively plentiful supply, that... 

Hydrocracking, the other major cracking operation, is predicted to grow approximately 3-5% annually, mainly because it operates at relatively high hydrogen pressure (typically >100 atm), which results in high removal rates of S and N heteroatoms from the feedstock and deep saturation of aromatic compounds. Consequently, it produces middle distillates with excellent product qualities, namely, jet and diesel fractions with very low sulfur content and very good combustion properties. 

Figure 2-2 Sulfur content (wt%) of distillation products from a West Texas crude oil. 

Figure 7-4 Sulfur content of distillation products of a California crude oil. 

Table IV gives the properties of the SRC-II fuel oil compared to a low-sulfur residual oil utilized in a recent combustion test. The SRC-II fuel oil is a distillate product with a nominal boiling range of 350-900°F, a viscosity of 40 Saybolt seconds at 100°F and a pour point below -20°F. Thus, it is readily pumpable at all temperatures normally encountered in transportation of the fuel oil. The fuel oil has a very low content of ash and sediment as well as a low Conradson carbon residue. These characteristics are favorable from the standpoint of particulate emissions during combustion. Tests of compatibility with typical petroleum fuel oils and on stability of the coal distillates over time have not revealed any unusual characteristics that would preclude utilization of these coal-derived fuels in conventional boiler applications.

Hydrotreated shale oil has an advantage as a refinery feed. In contrast to most petroleum crude oils, it contains essentially no residuum. Properties of the hydrotreated product from whole shale oil are similar to those of distillate fractions from waxy petroleum Arabian or Sumatran crudes. An exception is the sulfur content which is much lower for hydrotreated shale oil than for most crudes. 

The Mizushima Oil Refinery of Japan Energy Corporation first implemented a high conversion operation of vacuum residue, versus a constant desulfurization operation, in the commercial residue hydrodesulfurization unit equipped with fixed-bed reactors, to produce more middle distillates as well as fuel oil with lower viscosity. The catalysts will be replaced when the sulfur content in the product oil reaches the allowable limit. Since we have believed that an increase in the residue conversion decreases the catalyst activity by coke deposition, we have been interested in controlling the coke deactivation to maximize the residue conversion during a scheduled operating period. 

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