Coke (fuel)
 | Coke is an important material in metallurgy (particularly steel making). It is made, basically, by heating high-grade coal in oxygen-less atmosphere. | |||||||
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Definitions
PI - Pollution Index. Indication of the amount and severity of the pollution generated during the life cycle of an item. The higher number, the more pollution.
DI - Depletion Index. Indication of the amount of resources used during production and disposal of an item. The higher number, the more resources are used (and the less sustainable the product is).
EI - Entropy Index. - Indication of the amount of energy wasted during the life cycle of an item. The higher number, the more energy is wasted.
CEII - Composite Environmental Impact Index. Indication of the item's impact on the environment, taking into account the resources used and the pollution generated during production, use, and disposal of the item. The higher number, the higher impact.
Comments
1 comment postedVolatile constituents of the coal—including water, coal-gas, and coal-tar—are driven off by baking in an airless furnace or oven at temperatures as high as 2,000 degrees Celsius. This fuses together the fixed carbon and residual ash. Most modern facilities have "by-product" coking ovens. Today, the hydrocarbons are considered by-products of coke-making, but many American steel companies capture and use them to create other products. Non by-product coking furnaces or coke furnaces (ovens) burn the hydrocarbon gases produced by the coke-making process to drive the carbonization process.
Bituminous coal must meet a set of criteria for use as coking coal, determined by particular coal assay techniques. These include moisture content, ash content, sulfur content, volatile content, tar, and plasticity.
The greater the volatile matter in coal, the more by-product can be produced, but too low or too high levels of volatile matter in the coal results in inferior coke produced in respect to coke quality properties. It is generally considered that levels of 26-29 % of volatile matter in the coal blend is good for coking purposes. Thus different types of coal are proportionally blended to reach acceptable levels of volatility before the coking process begins.