Maximum cracking degree determination method of coking raw material

Abstract

The present invention relates to a maximum cracking degree determination method of a coking raw material. The method comprises: taking 5-20 g of a coking raw material oil sample to carry out a heat reaction test, controlling the reaction temperature of 410-450 DEG C and the reaction time of 5-40 min, collecting the gas, the liquid and the residues oil sample, weighing, carrying out chromatographic simulated distillation on part of the residue oil after the reaction and the raw material oil, adopting the sum of the increment of the distillate with the boiling range of less than or equal to 540 DEG C before and after the reaction and the gas yield to characterize the cracking depth, washing the other part of the residue oil after the reaction with toluene, carrying out centrifugation separation, adopting the yield of the after-reaction toluene insoluble to characterize the condensation depth, and controlling different reaction conditions to obtain the oil sample cracking-condensation curve, wherein the curve inflection point is the maximum cracking degree of the oil sample. With application of the method to determining the maximum cracking degree of the coking raw material, characteristics of convenience, fastness, accuracy and reliability are provided.

Description

technical field [0001] The invention relates to a method for measuring the maximum crackability of coking raw materials, in particular to the field of delayed coking for heating heavy oil in petroleum processing. Background technique [0002] Delayed coking is a process that utilizes the characteristics of heavy oil that is not easy to produce coking precursors when the thermal conversion depth is low, obtains the energy required for the lightening of heavy oil in the coking heating furnace tube, and then completes the coke formation reaction in the coke tower . Controlling the coking rate of the coking furnace tube is the basis for ensuring the long-term operation of the delayed coking unit; maximizing the amount of heat given by the coking furnace to the coking reaction (heat absorption) ensures the heat required for the coking reaction (heat absorption), and reduces the coke production rate of the unit. The technological key to obtaining economic benefits in this process...

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Problems solved by technology

[0004] When the cracking depth is low, the formation of coking precursors cannot be detected in the experiment; but when the cracking depth increases to the appearance of coking precursors, the yield of coking precursors increases rapidly with the increase of cracking depth, and the cracking depth and condensation depth ( Toluene insoluble product yield) curve obviously has an accelerated "inflection point" phenomenon; the reason for this phenomenon may be that the cracking reaction of heavy oil is a free radical reaction process, and when the cracking depth of the reaction is low, the free radicals generated in the reaction process are destroyed The "cage" of heavy oil colloids hinders the further superposition of free radicals, so the formation of coke precursors is slow; once the cracking depth increases, resulting in an increase in the concentration of free radicals, the "cage" effect of heavy oil colloids is destroyed, the superposition between free radicals is unobstructed, and the yield of coke precursors increases sharply with the increase of cleavage depth

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