Black coke

Allotropic forms of carbon. In the solid state, the element carbon exists in three different allotropic modifications—amorphous carbon and the two crystalline forms known as diamond and graphite. Amorphous carbon includes numerous common products such as wood charcoal, bone black, coke, lamp black, and carbon black. Each of these varieties of crystalline and amorphous carbon possesses properties that render it useful for a variety of purposes. 

A reactor constructed of stainless steel 410 was used for pyrolysis since it contained no nickel. The coke layer formed during pyrolysis was usually thin and greyish. Less frequently, a piece of black coke was found on the surface. The metal surface (Surface C) was always grey. Figure 5 shows the two types of coke formed at Surface A in the stainless steel 410 reactor. The black (less frequent) coke appeared to be a floe of fine filaments, about 0.05 / m in diameter, with occasional 0.4- m filaments. The predominant deposit seems to be platelets of coke that include metal crystallite inclusions, the lighter area. The metal particles in the coke deposits, as detected by EDAX, were chromium rich compared with the bulk metal, as reported in Table III. Some sulfur also was present in the deposit the sulfur was present, no doubt, because of the prior treatment of the surface with hydrogen sulfide. Surfaces B and C for the stainless steel 410 reactor are also shown in Figure 6. Surface B indicated porous coke platelets. Surface C was covered mostly with coke platelets, and cavities existed on the surface. Metal crystallites rich in iron apparently were pulled from the metal surface and were now rather firmly bound to Surface B. Surface C was richer in chromium than the bulk metal. 

Passage of the off-gases through a mass of bone-black, coke, or pumice results in the dismutation of the phosgene into tetrachloromethane and carbon dioxide (see Section 8.2). 

Alumina Aluminum hydroxide Attapulgite Bone black Coke... 

Only one calcium halide is known to have been used as a pigment, die calcium fluoride mineral fluorite q.v.). However, it has been suggested that bone (widely known as a pigment and used eidier as a white calcination product or a black coke) is to be considered a fluorinated calcium phosphate, fluorapatite (qq.v.). 

Graphite and diamond are two well-known structures of elemental carbon, but many other forms of elemental carbon, such as carbon black, coke, and the more recently discovered fullerenes and nanotubes have many industrial applications. 

A Class II - Group F atmospheres containing carbon black, coke or coal dust. 

Particulate carbon as soot, carbon black, coke, and graphite originates from auto and truck exhausts, heating furnaces, incinerators, power plants, and steel and foimdry operations, and composes one of the more visible and troublesome particulate air pollutants. Because of its good adsorbent properties, carbon can be a carrier of gaseous and other particulate pollutants. Particulate carbon surfaces may catalyze some heterogeneous atmospheric reactions, including the important conversion of SO2 to sulfate. 

All modern refineries have conversion units, designed to transform black effluent streams into lighter products gas, gasoline, diesel fuel. Among these conversion units, coking processes take place by pyrolysis and push the cracking reaction so far that the residue from the operation is very heavy it is called coke . 

Approximately 50—55% of the product from a coal-tar refinery is pitch and another 30% is creosote. The remaining 15—20% is the chemical oil, about half of which is naphthalene. Creosote is used as a feedstock for production of carbon black and as a wood preservative. Because of modifications to modem coking processes, tar acids such as phenol and cresyUc acids are contained in coal tar in lower quantity than in the past. To achieve economies of scale, these tar acids are removed from cmde coal tar with a caustic wash and sent to a central processing plant where materials from a number of refiners are combined for recovery. 

The carbon black (soot) produced in the partial combustion and electrical discharge processes is of rather small particle si2e and contains substantial amounts of higher (mostly aromatic) hydrocarbons which may render it hydrophobic, sticky, and difficult to remove by filtration. Electrostatic units, combined with water scmbbers, moving coke beds, and bag filters, are used for the removal of soot. The recovery is illustrated by the BASF separation and purification system (23). The bulk of the carbon in the reactor effluent is removed by a water scmbber (quencher). Residual carbon clean-up is by electrostatic filtering in the case of methane feedstock, and by coke particles if the feed is naphtha. Carbon in the quench water is concentrated by flotation, then burned. 

Blast furnaces are charged through the top with coke, flux (usually iron metal and siUca), and scrap while air is iajected through tuyeres continuously at the bottom just above the black copper. The coke (100 kg/1 slag) bums to maintain furnace temperatures of 1200°C, provides the reductant, and maintains an open border. A charge of 10 t/h is typical. The furnace produces a molten black copper that contains about 80% copper. The 2iac, lead, and... 

Production. In the commercial production of strontium carbonate, celestite ore is cmshed, ground, and stored in bins before it is fed to rotary kilns. As the ground ore is being conveyed to the kilns, it is mixed with ground coke. In the kilns, the celestite is reduced to strontium sulfide [1314-96-1J, known as black ash, according to the reaction ... 

Most barium compounds are prepared from reactions of barium carbonate [513-77-9] BaCO, which is commercially manufactured by the "black ash" process from barite and coke ki a process identical to that for strontium carbonate production. Depending on the co-product, soda ash and/or carbon dioxide are also consumed. 

Of the alkaline-earth carbonates, BaCO requires the greatest amount of heat to undergo decomposition to the oxide. Thus carbon in the form of coke, tar, or carbon black, is added to the carbonate to lower reaction temperature from about 1300°C in the absence of carbon to about 1050°C. The potential for the reverse reaction is decreased by removing the CO2 as shown in equation lb. 

Property Modifiers. Property modifiers can, in general, be divided into two classes nonabrasive and abrasive, and the nonabrasive modifiers can be further classified as high friction or low friction. The most frequently used nonabrasive modifier is a cured resinous friction dust derived from cashew nutshell Hquid (see Nuts). Ground mbber is used in particle sizes similar to or slightly coarser than those of the cashew friction dusts for noise, wear, and abrasion control. Carbon black (qv), petroleum coke flour, natural and synthetic graphite, or other carbonaceous materials (see Carbon) are used to control the friction and improve wear, when abrasives are used, or to reduce noise. The above mentioned modifiers are primarily used in organic and semimetallic materials, except for graphite which is used in all friction materials. 

Carbon black from oil is the main competition for the product from coal, which is used in filters. Carbon for electrodes is primarily made from petroleum coke, although pitch coke is used in Germany for this product. The pitch binder used for electrodes and other carbon products is almost always a selected coal tar pitch. 

Product separation for main fractionators is also often called black oil separation. Main fractionators are typically used for such operations as preflash separation, atmospheric crude, gas oil crude, vacuum preflash crude, vacuum crude, visbreaking, coking, and fluid catalytic cracking. In all these services the object is to recover clean, boiling range components from a black multicomponent mixture. But main fractionators are also used in hydrocracker downstream processing. This operation has a clean feed. Nevertheless, whenever you hear the term black oil, understand that what is really meant is main fractionator processing. 

Three other forms of carbon are manufactured on a vast scale and used extensively in industry coke, carbon black, and activated carbon. The production and uses of these impure forms of carbon are briefly discussed in the Panel on p. 274. 

Production and Uses of Coke, Carbon Black and Activated Carbon ... 

Pech-kiefer,/. pitch pine, -kohle,/. pitch coal jet. -koks, m. coke from pitch or tar. -ol, n. tar oil, oil of tar, -pflaster, n. asphalt paving. -riickstand, m. pitch residue, pechschwarz, a. pitch-black. 

The heaviest products obtained directly from oil arc lubricants, waxes, asphalt, and coke. These products have both domestic and industrial uses. Lubricants, for example, are applied in the operation and maintenance of industrial equipment and machinery. Asphalt, because it is not reactive to chemicals in the environment, is a superb material of construction in the building of roads and in roofing. It is also used in the waterproofing of concrete, the manufacture of black paints, and as a material lor tire threads, battery housing, electrical insulation, and other applications. The heaviest of all the petroleum products, coke, is used extensively as a major component of industrial electrodes and as a commercial fuel. 

Group F Garbon black, coal, or coke dust... 

Soft carbon is also classified by its crystallinity. For example, acetylene black and carbon black are regarded as typical carbon materials with low crystallinity. Coke materials are carbon materials with intermediate crystallinity. It is easy to obtain these materials because they are made from petroleum and coal and they were actively studied in the 1980s. In contrast, there are some graphite materials which have high crystallinity their capacity is greater than that of coke materials, and these materials have been studied more recently, in the 1990s [76-80]. 

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