Centro Sperimentale Metallurgico S.p.a.

Luigi Palumbo

Angelo Colletta

Giampaolo Giromella

A carbonaceous material with high characteristics of surface area and activity is produced in a continuous process by heating and drying ground pit coal at 200 to 300.degree. C. for 15 to 120 minutes in air, and then heating in two further stages in fluidized bed reactors. The first of these further stages is 400 to 600.degree. C. for 10 to 60 minutes while the second is 800 to 1100.degree. C. for 10 to 60 minutes. Tar is condensed from the offgases of the first further stage and the residual gas is divided and 10 to 95% recycled to the first further stage. Similarly, 10 to 95% of the off-gases from the second further stage are recycled.

Carbonaceous material with high characteristics of surface area and

Coke is produced with high yield and low sulfur by heating and drying ground coking coal at 200.degree. to 300.degree. C. for 15 to 120 minutes in air, and then heating in two semicoking stages in nitrogen in fluidized bed reactors. The first semicoking stage is 400.degree. to 600.degree. C. for 10 to 60 minutes while the second is 800.degree. to 1,100.degree. C. for 10 to 60 minutes. Tar is condensed from the offgases of the first semicoking stage and the residual gas is divided and 15 to 95% recycled to the first semicoking reactor. Similarly, 15 to 95% of the offgases from the second semicoking reactor is recycled. The condensed tar is fed to the final coke-forming operation.

Coke production

Coke is produced with high yield and low sulfur by heating and drying ground coking coal at 200.degree. to 300.degree. C. for 15 to 120 minutes in air, and then heating in three semicoking stages in fluidized bed reactors. The first semicoking stage is 300.degree. to 470.degree. C. for 10 to 20 minutes; the second is 400.degree. to 600.degree. C. for 10 to 20 minutes; while the third is 800.degree. to 1100.degree. C. for 10 to 20 minutes. Tar is condensed from the offgases of the first two semicoking stages and the residual gas from each is divided and 60 to 80% recycled as fluidizing gas to the same semicoking reactor. 10 to 20% of the offgases from the third semicoking stage is recycled to the third stage as fluidizing gas. In addition, oxygen is used as make-up fluidizing gas in each of the three stages, in the amount of 10 to 30 liters per kilogram of dry coal in the first stage, 5 to 20 liters per kilogram of dry coal in the second stage, and 40 to 100 liters per kilogram of dry coal in the third stage. The offgas from the third stage is high in reducing power. The condensed tar is fed to the final coke-forming operation.

In the production of formed coke, the temperatures and times of the oxidation and carbonization phases can be reduced if 5 to 12% by volume of oxygen is included in the fluidizing gas in a fluidized bed reactor in which the carbonization phase is conducted.

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Rome, Italy

Luigi Palumbo