Co-carbonization of ethylene tar pitch and coal tar pitch to form needle coke

The co-carbonization of ethylene tar pitch (ETP) and coal tar pitch (CTP) was studied in a tube bomb. A small amount of CTP was found to effectively modify the carbonization properties of ETP to produce excellent needle coke of low nitrogen content without formation of mosaic coke at the reactor bottom (bottom mosaic coke) in a wide range of carbonization temperatures and pressures. Blending 30–50 wt% CTP into ETP provided lump coke of thin lamellar flow texture, with a good CTE value and nitrogen content after calcination at 1000 °C. The influences of carbonization temperature and pressure on the nitrogen remaining in the coke were also investigated.