Improved method of delay coking process

Abstract

The invention provides a method for improving the delayed coking technique. The method is as follows: coked raw material residual oil is heated by a heating furnace and enters into a coking tower; coke generated is accumulated in the coking tower; and gas, naphtha, light diesel oil, heavy diesel oil, light wax oil and heavy wax oil are obtained after separation of oil gas fluid products through a coking and fractionating tower. The light diesel oil, the heavy diesel oil, the light wax oil or the heavy wax oil are used as circulation materials through adjustment of the sources, the distillation range and the circulation of the circulation materials, and then the coking induction period of mixture can be prolonged and the coking dynamics of the coked raw material residual oil can be changed; and the coking reaction of the residual oil is delayed to be performed in the coking tower more completely, thereby achieving the aim of prolonging the operating period of a heating furnace tube. The operating period of the coking and heating furnace can be prolonged to be between 3 and 18 months generally according to the extended degree of the coking induction period determined by the sources, the distillation range and the circulation of the circulation materials selected.

Description

technical field [0001] The invention belongs to the technical field of chemical engineering, and relates to a delayed coking process improvement method. Specifically, a distillate oil derived from petroleum and coal tar is circulated to prolong the coking induction period of the coking raw material residue to make the coking reaction It is fully delayed to the coke tower to effectively prevent coking in the heating furnace tube, thereby prolonging the start-up period of the coking heating furnace tube. Background technique [0002] Delayed coking is a decarbonization process that can process residual oil raw materials from a wide range of sources to obtain high value-added light oil products. Since the coking process does not use catalysts, there is no restriction on the residual carbon value of raw materials, metal content, etc.; the investment and operating costs of the delayed coking process are low, and it has generally become residual oil (especially low-quality residue...

AI Technical Summary

Problems solved by technology

In order to prevent the clogging of heating furnace tubes in industry, water steam injection or large circulation ratio measures are often adopted to reduce the residence time of residual oil raw materials in heating furnace tubes and prevent coke deposition and agglomeration, but these measures cause energy consumption of the process system increase, and even induce the production of projectile coke, bringing production hazards

Patent CN1286947C divides a coking cycle into three stages. From one stage to the next stage, it is necessary to adjust the temperature of the heating furnace and switch different raw material oil products. Such frequent adjustments are difficult to achieve smooth operation for large coking units.