Needle coke

Table 1. Typical Properties of Isotropic and Needle Cokes ...

Property Aluminum anode-grade coke Graphite electrode-grade needle coke... 

Coal-Tar Pitch Coke. Coal-tar pitch is used to produce needle coke primarily in Japan. Processes for producing needle coke from pitch have also been developed in Germany (4). The key to producing needle coke from coal tar or coal-tar pitch is the removal of the high concentrations of infusible sohds, or material insoluble in quinoline (QI), which are present in the original tar. The QI inhibits the growth of mesophase and results in an isotropic, high CTE coke from coal-tar pitch. After removal of the QI, very anisotropic and low CTE cokes are obtained from coal-tar-based materials. 

Petroleum cokes, on the other hand, represent the second largest source of consumable industrial carbon in the United States. In 1992, about 2 million tons of anode coke and 250,000 tons of needle coke were used in the United States. 

Coke produced from delayed coking is described as delayed sponge, shot, or needle coke depending on its physical structure. Shot coke is the most common when running the unit under severe conditions with sour crude residues. Needle coke is produced from selected aromatic feedstocks. Sponge coke is more porous and has a high surface area. The properties and markets for petroleum cokes have been reviewed by Dymond. Table 3-4 shows the types of petroleum cokes and their uses. ... 

A schematic diagram of the liquid solvent extraction process is illustrated in Figure 1. Where the production of liquid hydrocarbons is the main objective an hydrogenated donor process solvent is used, whereas in the production of needle coke this is not necessary and a coal derived high boiling aromatic solvent may be used (e.g. anthracene oil). An essential economic requirement of the process is that a high extraction yield of the coal is obtained and this will depend upon the coal used and the digestion conditions. 

Petroleum petroleum pitch delayed coke, calcined coke needle coke, carbon fibers, binder and matrix carbon1... 

Needle coke Ribbonlike parallel-ordered anisotropic domains that can also occur as folded structures... 

Most petroleum coke is used for fuel, but some premium delayed coke known as needle coke is used to make anodes for the aluminum industry. That coke is first calcined to less than 0.5 percent volatiles at 1300 to 1400°C before it is used to make anodes. 

In a study of the carbonization (- 525°C) and graphitization (- 2500°C) of thianthrene in comparison with anthracene, it was shown that the carbons of the heterocycle are nongraphitable between 1200°C and 2500°C, sulfur was evolved continuously (85MI3). Aluminum chloride catalytic carbonization of thianthrene has also been studied. At lower temperatures than without a catalyst, thianthrene produced an isotropic coke catalytic co-carbonization with anthracene and 9,10-dihydroanth-racene gave mosaic and needle cokes, respectively (80MI6, 80MI7). Po-ly(arylene sulfides) were shown to be produced by aluminum chloride treatment of thianthrene at 180-350°C (79URP659582). 

Thirty papers were presented at the 1984 symposium. Speakers were free to develop their topics, but encouraged to focus on their own work and to provide full reference lists for readers who wish to pursue particular topics in further depth. The twenty-five papers appearing in this volume were completed after the symposium so that authors could write with the benefits of the questions and discussions at the symposium. One paper entitled Feedstocks for Carbon Black, Needle Coke, and Electrode Pitch, was published elsewhere, and readers are referred to that publication (75) for an analysis of market trends and an outlook for heavy aromatic oil supplies. Two other papers were also published elsewhere, and these appeared substantially in the same form as in the symposium preprints (14, 15). 

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