Boiler fuel distillate

It is anticipated that coal derived liquids boiling above about 350 F will be disposed of to the utility market. Table V summarizes the potential utility markets for various types of coal derived fuels which include solvent refined coal, heavy boiler fuels, distillate boiler fuels, turbine fuels and methanol. Speculative locations for these markets are indicated on Figure 2. 

The Fischer-Tropsch technology produces a wide variety of products which can be narrowed to gasoline, diesel fuel, boiler fuel, distillate oil, and synthetic natural gas. 

Solvent Refined Coal Process. Work ia the mid-1960s by the Speacer Chemical Co. (9) and dating the 1970s by the Gulf Chemical Corp. led to two solvent refined coal (SRC) processiag schemes SRC-I for productioa of low ash soHd boiler fuels and SRC-II for distillates, eg, "syn-cmde."... 

The volatile products from the soaking drum enter the fractionator where the distillates are fractionated into desired product oil streams, including a heavy gas oil fraction. The cracked gas product is compressed and used as refinery fuel gas after sweetening. The cracked oil product after hydrotreating is used as fluid catalytic cracking or hydrocracker feedstock. The residuum is suitable for use as boiler fuel, road asphalt, binder for the coking industry, and as a feedstock for partial oxidation. 

Although the first major use of coal liquids will be as boiler fuels, it is clear that in order to make the largest impact on the U.S. liquid fuel demand, products from direct liquefaction have to be upgraded to quality liquid fuels for both transportation and home heating oil uses. The products coming from the all-distillate coal liquefaction processes such as H-Coal Syncrude, SRC-II and Donor Solvent, along with shale oil production will be candidates for use as refinery feedstock. 

A brief outline of the products expected in a demonstration plant and in future commercial plants is shown in Figure 2. In future commercial plants, for example, ethane and propane could be utilized as chemical intermediates and naphtha as a source of chemicals or for production of high-octane unleaded gasoline. Synthesis gas produced in excess of the requirements for hydrogen could be utilized as a source of chemicals as well as a fuel. The fuel oil could be selectively fractionated to produce a middle distillate for use as turbine fuel, light industrial boiler fuel or refinery feedstocks, while the heavy distillate could serve as a fuel oil for large utility boilers. 

The medium oil contains quite low sulfur, but has a slightly lower pour point compared with commercial heavy oil A. It is used as a boiler fuel for the sewage treatment plant in Niigata city. The heavy fraction contains quite low sulfur and is used in a paper and pulp factory in Niigata city. The distillation properties of the oils are shown in Figure 26.3. 

The solvent-refined coal (SRC) processes were originally developed to produce cleaner boiler fuels from coal. A 0.5t/day plant was built in 1965 and scaled up in 1974 into two separate pilot plants located at Wilsonville (SRC-I, 6t/day) and Fort Lewis, WA (SRC-I, 50t/day). The Fort Lewis plant was later converted to an SRC-II unit. Due to the more severe conditions required for SRC-II, the capacity was downgraded to about 25 t/day. The objective of the SRC-II process was to produce distillate products. Detailed designs for large-scale plant were subsequently prepared, although these plants were not built. The Wilsonville plant continued to be funded... 

A general term applied to oil used for the production of power or heat. In a more restricted sense, it is applied to any petroleum product that is used as boiler fuel or in industrial furnaces. These oils are normally residues, but blends of distillates and residues are also used as fuel oil. The wider term, liquid fuel is sometimes used, but the term fuel oil is preferred. 

It is difficult to use as boiler fuel because of its 2.75% sulfur content. It is often utilized by blending it in bunker fuel or by converting it to acceptable distillate fuels by coking followed by hydrotreating. 

As mentioned already in the previous chapter, an alcohol mixture which is to be used as octane booster for motor fuels must not contain more than approximately 0.5 wt. % of water. It must also be stable , i.e. storable. Alcohol/water mixes, which contain much higher quantities of water, must therefore be purified to remove the low boilers and distilled to reduce their water content. 

The "H-COAL" process was developed by Hydrocarbon Research Inc. to convert all types of coal to high octane gasoline, petrochemicals, LPG, low sulfur distillate fuels and low sulfur heavy boiler fuel oil. 

Pitch and Tar The liquid and semiliquid residues from the distillation of petroleum and coal are known as pitch and tar. Most of these residues are suitable for use as boiler fuels. Some handle as easily and burn as readily as does kerosene, whereas others give considerable trouble. 

Boiler Fuels Feeds Heavy oils and distillation resides... 

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-... 

No. 2 fuel oil is a petroleum distillate that may be referred to as domestic fuel oil or industrial fuel oil. Domestic fuel oil is usually lighter and straight-run refined it is used primarily for home heating and to produce diesel fuel. Industrial distillate is the cracked type, or a blend of straight-run and cracked. It is used in smelting furnaces, ceramic kilns, and packaged boilers. 

Air emissions from a petroleum distillation unit include emissions from the combustion of fuels in process heaters and boilers, fugitive emissions of volatile constituents in the crude oil and fractions, and emissions from process vents. The primary source of emissions is combustion of fuels in the crude preheat furnace and in boilers that produce steam for process heat and stripping. When operating in an optimum condition and burning cleaner fuels (e.g., natural gas, refinery gas), these heating units create relatively low emissions of sulfur oxides, (SO c), nitrogen oxides (NO c), carbon monoxide (CO), hydrogen sulfide (H2S), particulate... 

Fuels used in marine applications are quite diverse in their properties. Low-viscosity distillate fuels and high-viscosity residual fuels can both be considered marine fuels. The applications, though, would differ and could include use in direct injected diesel engines, boilers, and gas turbines. Also, high-speed, medium-speed, and slow-speed engines can be found in marine applications. 

Marine residual fuels bunker fuel oil Grades ISO RMA through RML marine residual fuel and bunker fuel are blended from components such as atmospheric resid, vacuum resid, visbreaker resid, FCC bottoms, low-grade distillate, and cracked components. Bunker fuel has a maximum viscosity of 550 cSt 122°F (50°C), density of 0.990 g/cc, and sediment of 0.1 wt%. ISO marine fuel oil viscosities range from 10 to 55 cSt 212°F (100°C). These fuels are used in slow-speed diesel engines and boilers. 

Several methods of carbon dioxide production are in commercial use. These include the reaction between sulphuric acid and sodium bicarbonate, the combustion of fuel oil, the extraction of carbon dioxide from the flue gas of a boiler or similar heating facility, the distillation of alcohol and the fermentation of beer carbon dioxide is also a byproduct of fertiliser manufacture. Following manufacture the gas must be cleaned to ensure it is free from impurities and is fit for purpose. Two typical processes are described below. 

Feeds and Products, Barrels per Calendar Day Ref inery Input Severity Hydrotreating Distillate Hydrotreating and Catalytic Reforming Hydrogen Manufacture and Sulfur Plant Boiler Plant Refinery Fuel Motor Gasoline Kerosene Jet Fuel By- Products... 

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.

The low viscosity and pour point characteristics of the SRC-II distillates are also attractive in industrial boiler and industrial cogeneration applications substituting for No. 2 fuel oil or natural gas. Demonstration burn programs in industrial boilers are being planned. 

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