Distillate fuels

Oxidation stability (distillate fuel oil) NF M 07-047 ISO/DlS 12205 ASTM D 2274 Measurement of precipitate after 16 h of oxygen sparging at 95°C... 

B. K. Schmid and D. M. Jackson, "The SRC-11 Process," paper presented at Third Annual International Conference on Coal Gasification and Eiquefaction. University of Pittsburgh, Aug. 3—5, 1976 D. M. Jackson and B. K. Schmid, "Production of Distillate Fuels by SRC-11," paper presented at ACS Div. of Ind. and Eng. Chem. Symposium, Colorado Spriags, Col., Feb. 12,1979. 

Cmde oil can be easily separated into its principal products, ie, gasoline, distillate fuels, and residual fuels, by simple distillation. However, neither the amounts nor quaUty of these natural products matches demand. The refining industry has devoted considerable research and engineering effort as well as financial resources to convert naturally occurring molecules into acceptable fuels. Industry s main challenge has been to devise new ways to meet the tremendous demand for gasoline without, at the same time, overproducing other petroleum products. 

Regulations generally prohibit disposal of lubricants in streams, chemical dumps, or other environmental channels. Over half of disposed lubricants are burned as fuel, usually mixed with virgin residual and distillate fuels (77). 

Catalysis. As of mid-1995, zeoHte-based catalysts are employed in catalytic cracking, hydrocracking, isomerization of paraffins and substituted aromatics, disproportionation and alkylation of aromatics, dewaxing of distillate fuels and lube basestocks, and in a process for converting methanol to hydrocarbons (54). 

The word distillate is occasionally used by petroleum chemists with a specialized meaning. Although anything that has been distilled is, of course, a distillate, the term distillate is sometimes used to denote distillate fuel oil as opposed to residual fuel oil. 

Domestic fuel oils are those used primarily in the home and include kerosene, stove oil, and furnace fuel oil. Diesel fuel oils are also distillate fuel oils, but residual oils have been successhjlly used to power marine diesel engines, and mixtures of distillates and residuals have been used on locomotive diesels. Heavy fuel oils include a variety of oils, ranging from distillates to residual oils, that must be heated to 260°C or higher before they can be used. In general, heavy fuel oil consists of residual oil blended with distillate to suit specific needs. Heavy fuel oil includes various industrial oils and, when used to fuel ships, is called bunker oil. 

ASTM (atmospheric) ASTM D 86 Petroleum fractions or products, including gasolines, turbine fuels, naphthas, kerosines, gas oils, distillate fuel oils, and solvents that do not tend to decompose when vaporized at 760 mmHg... 

Shell Gas B.V. has constructed a 1987 mVd (12,500 bbhd) Fischer-Tropsch plant in Malaysia, start-up occurring in 1994. The Shell Middle Distillate Synthesis (SMDS) process, as it is called, uses natural gas as the feedstock to fixed-bed reactors containing cobalt-based cat- yst. The heavy hydrocarbons from the Fischer-Tropsch reactors are converted to distillate fuels by hydrocracking and hydroisomerization. The quality of the products is very high, the diesel fuel having a cetane number in excess of 75. 

Contaminants in fuels, especially alkali-metal ions, vanadium, and sulfur compounds, tend to react in the combustion zone to form molten fluxes which dissolve the protective oxide film on stainless steels, allowing oxidation to proceed at a rapid rate. This problem is becoming more common as the high cost and short supply of natural gas and distillate fuel oils force increased usage of residual fuel oils and coal. 

In general terms, the life of a combustor might be reduced by about 30 percent through use of a distillate fuel and by 80 percent through the use of residual fuel. The first stage turbine nozzle life can Be reduced by 20 percent through use of a distillate fuel and by about 6.5 percent when certain residual fuels are used. 

Since the reliability of gas turbines in the power industry has been lower than desired in recent years because of hot-corrosion problems, techniques have been developed to detect and control the parameters that cause these problems. By monitoring the water content and corrosive contaminant in the fuel line, any changes in fuel quality can be noted and corrective measures initiated. The concept here is that Na contaminants in the fuel are caused from external sources such as seawater thus, by monitoring water content, Na content is automatically being monitored. This on-line technique is adequate for lighter distillate fuels. For heavier fuels, a more complete analysis of the fuel should be carried out at least once a month using the batch-type system. The data should be input directly to the computer. The water and corrosion detecting systems also operate in conjunction with the batch analysis for the heavier fuels. 

Another U.S. policy to attain energy independence was to force all Alaskan North Slope crude oil to he consumed inside the United States and not be allowed to he exported. The problem was that North Slope crude oil is relatively heavy and not suitable for west coast fuel needs. The mismatch of supply and demand caused California refineries to sell heavy distillate fuels abroad and import lighter fuel additives. Furthermore, the forced selling of Alaska crude oil on a very saturated west coast market caused Alaska crude prices to he 1 to 5 per barrel less than the international price, resulting in less oil exploration and development in Alaska. The upshot of all this was lower tax revenue, a loss of jobs in the oil fields, and less oil exploration and development on the North Slope. The United States actually exported heavy bunker fuel oil at a loss, as opposed to the profit that could have been attained by simply exporting crude oil directly. 

By the end ofWorld War II the use of residual fuel oil in the United States had reached about 1.2 million barrels per day. The bulk of this use was in industri-al/commercial boilers, railroad locomotives, and steamships. Shortly thereafter, railroad use declined rapidly as diesel engines, which used distillate fuel, replaced steam locomotives. In the 19.30s and 1960s residual fuel oil use for marine and industrial applications, as well as for electric power generation, con-... 

Recovering the bitumen is not easy, and the deposits are either strip-mined if they are near the surface, or recovered in situ if they are in deeper beds. The bitumen could be extracted by using hot water and steam and adding some alkali to disperse it. The produced bitumen is a very thick material having a density of approximately 1.05 g/cm. It is then subjected to a cracking process to produce distillate fuels and coke. The distillates are hydrotreated to saturate olefinic components. Table 1-8 is a typical analysis of Athabasca bitumen. ... 

Table 15.4 shows typical applications for the range of oil fuels for use with major prime movers. Medium/high-speed diesel engines generally use distillate fuel oils while medium/low-speed units generally bum residual fuels. The gas turbine, which normally operates on liquid distillate fuels, is capable of running on residual fuels, although examples of these are normally associated with crude production facilities. 

The NO t constituent in the exhaust of machines firing natural gas is some 150 to 160 ppm, and for distillate fuels typically 260 ppm. In order to reduce these levels to the targets quoted above, catalytic filters can be used, but the systems currently available are expensive. As an alternative, certain manufacturers are developing low-NO burners but these limit the user to natural gas firing. 

Electricity works (excluding compression-ignition engines burning distillate fuel with a sulfur content of <1 per cent) ... 

Table 5-1. Comparison of X-ray, Bomb-Sulfur, and Lamp-Sulfur Methods for the Determination of Sulfur in Distillate Fuels...

The liquid products were distilled to determine the yield and properties of the residual (343°C+) and light liquid (343°C ) products. Table VI shows that Runs 2 and 3 in Table IV resulted in 27 and 34 wt.% conversion of the 343°C+ fraction, while the sulfur in this fraction was reduced to 0.25 and 0.18 wt.%, respectively. The distillate and light liquid product (343°C ) are also upgraded in this process. The additional light distillates produced could presumably be recycled to the liquefaction reactor or utilized as low sulfur light distillate fuel. 

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