Fuel oils residual

The iQxm fuel oil is applied not only to distillate products (distillate fuel oil. Chapter 9) but also to residual material, which is distinguished from distillate type fuel oil by boiling range and, hence, is referred to as residual fuel oil (ASTM D-396). 

Detailed analysis of residual products, such as residual fuel oil, is more complex than the analysis of lower-molecular-weight liquid products. As with other products, there are a variety of physical property measurements that are required to determine whether the residual fuel oil meets specification, but the range of molecular types present in petroleum products increases significantly with an increase in the molecular weight (i.e., an increase in the number of carbon atoms per molecule). Therefore, characterization measurements or studies cannot, and do not, focus on the identification of specific molecular structures. The focus tends to be on molecular classes (paraffins, naphthenes, aromatics, polycyclic compounds, and polar compounds). 

Several tests that are usually applied to the lower-molecular-weight colorless (or light-colored) products are not applied to residual fuel oil. For example, test methods such as those designed for the determination of the aniline point (or mixed aniline point) (ASTM D-611, IP 2) and the cloud point (ASTM D-2500, ASTM D-5771, ASTM D-5772, ASTM D-5773) can suffer from visibility effects because of the color of the fuel oil. 

The reduction in viscosity of residua tends to reach a limiting value with conversion, although the total product viscosity can continue to decrease but other properties will be affected. Sediment (which is predominantly organic but may contain some mineral matter) may also form—a crucial property for residual fuel oil—and conditions should be chosen so that sediment formation is minimal, if it occurs at all. When shipment of the visbreaker product by pipeline is the process objective, addition of a diluent such as gas condensate can be used to achieve a further reduction in viscosity. Recovery of the diluent after pipelining is an option. 

The significance of the measured properties of residual fuel oil is dependent to a large extent on the ultimate uses of the fuel oil. Such uses include steam generation for various processes as well as electrical power generation and propulsion. Corrosion, ash deposition, atmospheric pollution, and product contamination are side effects of the use of residual fuel oil, and in particular cases properties such as vanadium, sodium, and sulfur contents may be significant. 

These fractions can be used directly as refined or may be blended with lighter fractions to produce the following finished products  

The high flash point, good storage stability, and potential energy value make residual fuel a relatively safe and economical energy source. 

This value provides an indication of the potential heating value which can be provided by the residual fuel. The heat energy obtained per unit volume of fuel is greatest for fuels having a high specific gravity. 

The flash point identifies the minimum temperature at which fuel vapors will ignite. In residual fuel applications, this is helpful in determining whether fuel may be contaminated with high-flash materials. 

This is one of the more important properties of residual fuel oil. It is an indication of both the pumpability characteristics of the fuel and the fuel atomization quality. 

---

The conversion takes place at high temperature (820-850°C) and very short residence time (hundredth of seconds) in the presence of steam. The by-products are hydrogen, methane and a highly aromatic residual fuel-oil. 

Residual fuel-oil represented more than 20 to 25% of the crude and the content in pollutants (sulfur, nitrogen, metals) increased. 

Residential sheathing Residual fuel Residual fuel oil Residual gas analyzers... 

Heavy oil, ie, grade nos. 4, 5, and 6, and residual fuel oils light oils, ie, no. 2 heating oil, kerosene, and jet fuel and petroleum coke are deflvered at... 

Thermal Cracking. In addition to the gases obtained by distillation of cmde petroleum, further highly volatile products result from the subsequent processing of naphtha and middle distillate to produce gasoline, as well as from hydrodesulfurization processes involving treatment of naphthas, distillates, and residual fuels (5,61), and from the coking or similar thermal treatment of vacuum gas oils and residual fuel oils (5). 

Noncatalytic partial oxidation of residual fuel oil accounts for the remainder of world methanol production. Shell and Texaco ate the predominant hcensors for partial oxidation technology (16) the two differ principally in the mechanical details of mixing the feedstock and oxidant, in waste heat recovery, and in soHds management. 

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. 

Visbreaking. Viscosity breaking (reduction) is a mild cracking operation used to reduce the viscosity of residual fuel oils and residua (8). The process, evolved from the older and now obsolete thermal cracking processes, is classed as mild because the thermal reactions are not allowed to proceed to completion. 

The pricing of carbon black feedstocks depends on their alternate market as residual fuel oil, especially that of high sulfur No. 6 fuel oil. The actual price is deterrnined by the supply/demand relationships for these two markets. Feedstock cost contributes about 60% of the total manufacturing cost. The market price of carbon black is strongly dependent on the feedstock cost as shown in Figure 8. 

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. 

Chemical Designations - Synonyms Residual fuel oil. No 4 Chemical Formula Not applicable. 

Chemical Designations - Synonyms Residual fuel oil. No 5 Chemical Formula Not applicable. Observable Characteristics - Physical State (asshipped) Liquid Color. Brown Odor. Like kerosine characteristic. 

The high-chromium casting alloys (50% nickel, 50% chromium and 40% nickel, 60% chromium) are designated for use at temperatures up to 900 C in furnaces and boilers Ared by fuels containing vanadium, sulfur and sodium compounds (e.g., residual petroleum products). Alloys with lower chromium contents cannot be used with residual fuel oils at temperature above 6S0 C because the nickel reacts with the vanadium, sulfur and sodium -impurities to form compounds that are molten above 650 C [27]. 

A hydroskimming refinery lends itself to locations where the market demands for the major fuel products (gasoline, gas oil, and residual fuel oil) approximate the quantities of these products obtainable by distillation from the available crudes. A typical hydroskimming refinery would include the following ... 

While a desalter costs more to install than the flash drum system, it has the advantage of removing up to 95% of the salt from the oil permanently. Because less salt reaches the fractionating tower in a unit equipped with a desalter, a smaller quantity of corrosion products is formed due to high temperature breakdown and hydrolysis, and the salt content of the residual fuel oil is much lower. 

All of the world s major economies, as well as scores of smaller, low-income nations, rely mainly on hydrocarbons. Crude oil now supplies two-fifths of the world s primary energy (Table 1). There are distinct consumption patterns in the shares of light and hea vy oil products the United States burns more than 40 percent of all its liquid fuels as gasoline, Japan just a fifth and the residual fuel oil accounts for nearly a third of Japanese use, but for less than 3 percent of the U.S. total. Small countries of the Persian Gulf have the highest per capita oil consumption (more than 5 t a year in the United Arab Emirates and in Qatar) the U.S. rate is more than 2.5 t a year European means arc around 1 t China s mean is about 120 kg, and sub-Saharan Africa is well below 100 kg per capita. 

The residuum from vacuum distillation became, and still is, the basic component of residual fuel oil. It contains the heaviest fraction of the crude, including all the ash and asphaltenes. It is extremely high in viscosity and must be diluted with light distillate flux (a low viscosity distillate or residual fraction which is blended with a high viscosity residual fraction to yield a fuel in the desired viscosity range) to reach residual fuel viscosity. The lowest value distillates, usually cracked stocks, are used as flux. In some cases the vacuum residuum is visbroken to reduce its viscosity so that it requires less distillate flux. 

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-... 

By 1973 about 1.4 million barrels per day of residual fuel oil were used for electric power generation in the United States. This accounted for 16.8 percent of U.S. electricity generation, mostly in areas where cheap, foreign heavy fuel could be delivered by tanker. That same year, another 1.4 million barrels per day of heavy fuel oil were used in the United States for industrial and commercial applications. Worldwide during 1973 about 2.6 million barrels per day of residual fuel oil were used in marine diesel engines, and another 1.1 million barrels per day were used for steamship propulsion. 

---