Needle-like coke preparation method

Abstract

The invention provides a needle-like coke preparation method, which comprises that a raw material is heated to a temperature of 465-510 DEG C with a heating furnace, the heated raw material oil enters a coking tower, and the oil-gas produced from the reaction is discharged from the tower top; the produced oil-gas is separated to obtain gas, gasoline distillate, diesel oil distillate and wax oil distillate; and the wax oil distillate adopted as circulation oil is mixed with the raw material oil according to a certain circulation ratio, the mixture enters the coking tower, and a difficulty-coking substance is introduced from the lower material inlet of the coking tower when the outlet temperature of the heating furnace is higher than 490 DEG C until the reaction period is ended, and the generated needle-like coke is deposited on the bottom portion of the coking section. According to the present invention, the method uses the upper material feeding and the lower material feeding combined mode so as to effectively eliminate the disturbance of the material feeding on the eurytopic intermediate phase forming.

Description

technical field [0001] The invention relates to a method for preparing needle coke, in particular to a method for preparing needle coke with low coefficient of thermal expansion (CTE) and low volatile content by adopting a delayed coking process. Background technique [0002] Needle coke has the characteristics of low CTE and easy graphitization, and is the preferred material for the production of high-power and ultra-high-power graphite electrodes. During the formation of needle coke, the raw material oil needs to go through the process of formation, growth and fusion of small mesophase spheres, develop into a wide-area mesophase, and then form a linear texture structure under the action of air flow, and finally solidify Produce needle coke. In the early stage of coking, excessive disturbances in the system should be avoided to ensure the slow and stable development of mesophase spheres. The degree of development of mesophase directly affects the product performance of nee...

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Problems solved by technology

In addition, the entire coking reaction system is a temperature-variable operation process. The heat in the tower comes from the heat brought in by fresh raw materials. In order to gradually increase the temperature of the reaction system, it is often necessary to continuously increase the temperature of the heating furnace. Long-term high-temperature operation will inevitably lead to the heating of the furnace. internal coking

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