Coal distillation

Free-swelling tests are commonly used to measure a coal s caking characteristics. A sample of coal is packed in a cmcible or tube, without compaction, and heated at a fixed rate to about 800°C. Infusible coals distill without changing appearance or state of agglomeration. The fusible coals soften, fuse, and usually sweU. The profile of the resultant coke is compared to a series of reference profiles so that a swelling index can be assigned. The profiles represent indexes between 0 and 9. The best cokes come from coals having indexes between 4 and 9. 

Vegetable and fruit processing Coal distillation (coke ovens)... 

Cyanide Disinfectants SPA Sodium cyanide Copper cyanide Heat treatment of metal Coal distillation Electroplating Photographic Synthetic fibre Agriculture and horticulture Abattoirs Eood processing... 

Eluorides Hydrocarbons, general G S P A Hydrogen fluoride Calcium fluoride Cement Aluminium Coal distillation Petrochemicals Petroleum refineries... 

Sulphur oxides G Sulphur dioxide Sulphur trioxide Coal distillation Combustion of coal and heavy fuel oil Detergents (sulphonation of alkyl benzenes) Electricity generation... 

Kohle-rohx, n., -rohre,/. carbon tube, -schwe-lung, /. coal distillation, -stab, m. carbon rod. -Stahl, m. carbon steel, ordinary steel, -staub, m. coal dust charcoal diist. 

In the early days of organic chemistry, the word aromatic was used to describe such fragrant substances as benzaldehyde (from cherries, peaches, and almonds), toluene (from Tolu balsam), and benzene (from coal distillate). It was soon realized, however, that substances grouped as aromatic differed from most other organic compounds in their chemical behavior. 

Sulphur oxides G Sulphur dioxide Metal extraction and refining Coal distillation... 

Solid Anthracite coal bituminous coal lignite peat wood Coke charcoal petroleum coke breeze semi-coke (low-temperature coal distillate) pulverized coal... 

Hydrocarbons, general Calcium fluoride Aluminium Coal distillation Petrochemicals Refineries... 

Occupational exposure to 2,3-benzofuran may occur in several energy-related industries. 2,3-Benzofuran is part of the naphtha fraction of coal distillates and exposure is possible in coke production and coal gasification facilities (see Chapter 4). Exposure may also occur during the polymerization process used to produce coumarone-indene resin. 2,3-Benzofuran was not included in the NIOSH National Occupational Hazard Survey or the National Occupational Exposure Survey. However, the naphtha fraction of coal tar is considered in the NIOSH (1978) evaluation of occupational hazards associated with coal gasification. 

Table IV shows that the total tar acid yield increases with decreasing carbon content of the coal. Of the total tar acids for all the coals of Table IV, except the Pittsburgh bed coal, about 50% distill below 235° C. (458° F.) at atmospheric pressure. About 70% of the total tar acids from Pittsburgh bed coal distill below 235° C. (458° F.). These lower boiling tar acids are chiefly phenol, cresols, and xylenols, and they are present in the proportion 1 to 4 to 5, respectively. This proportion does not vary much with the carbon content of the coal. Data (86) on the character of the tar acids boiling above 235° (458° F.) show that ethylphenols and indanols are present in amounts of the same order of magnitude as that of the phenol in the > 235° C. (458° F.) fraction.

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