Abstract: A process is provided for determining the suitability of pyrolysis tar, such as steam cracker tar, for upgrading using hydroprocessing without long term fouling of the hydroprocessing reactor. The process includes heating a sample of the tar, quenching the sample, and measuring the total free radical content of the quenched sample. A pyrolysis tar can be blended with one having a lesser total free radical content to produce a blend that can be hydroprocessed with decreased fouling.

Abstract: A process is provided for determining the suitability of pyrolysis tar, such as steam cracker tar, for upgrading using hydroprocessing without long term fouling of the hydroprocessing reactor. The process includes heating a sample of the tar, quenching the sample, and measuring the total free radical content of the quenched sample. A pyrolysis tar can be blended with one having a lesser total free radical content to produce a blend that can be hydroprocessed with decreased fouling.

Abstract: A method and a system for producing calcium carbide, the method including mixing powdery carbon-containing raw material with powdery calcium-containing raw material, and directly heating the mixture by combusting a part of carbon-containing raw material in an oxygen-containing atmosphere to produce calcium carbide. The carbon-containing raw material can be coal, semi-coke or coke, the calcium-containing raw material can be calcium carbonate, calcium oxide, calcium hydroxide or carbide slag. The system includes a raw material preheating unit, such as a fluidized bed or an entrained flow bed, and a reaction unit such as an entrained flow bed. By combustion of the by-product CO produced during the production of calcium carbide or auxiliary fuel in the air to preheat the raw materials to 500-1500° C., the carbon consumption and the oxygen consumption for the calcium carbide production can be reduced, and thus process energy consumption is further reduced.