Method for inhibiting hydrocarbons steam cracking furnace from coking and carburizing

A technology of cracking furnace and steam, which is applied in cracking, non-catalytic thermal cracking, petroleum industry, etc. It can solve problems such as difficult maintenance, influence on downstream systems, and long time for injecting inhibitors, and achieves simple and easy operation methods and improved transmission Thermal effect, effect of suppressing catalytic coking

Active Publication Date: 2008-10-29
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Carburizing causes the furnace tube to creep and rupture, which greatly shortens the service life of the furnace tube
[0009] The existing coking suppression methods in the prior art have the following disadvantages: 1) It affects the downstream system, making the operation of the latter system difficult; 2) The additive is toxic and pollutes the environment; 3) The inhibitor is injected before the cracking furnace is put into oil. If the time is too long, the ethylene output will be reduced; 4) processing and maintenance are difficult and the cost is high; 5) the carburization of the cracking furnace tube cannot be effectively improved; 6) the effect of inhibiting coking and carburization is not ideal, etc.
[0011] However, only setting enhanced heat transfer furnace tubes such as twisted sheet tubes in the radiant section of the ethylene cracking furnace has limitations. The operating cycle of the furnace, but there is still coking between the enhanced heat transfer components such as twisted sheets and the inner wall of the furnace tube. After a period of operation, the cracking furnace will have to be shut down due to severe coking

Method used

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  • Method for inhibiting hydrocarbons steam cracking furnace from coking and carburizing
  • Method for inhibiting hydrocarbons steam cracking furnace from coking and carburizing

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] Example 1 and Example 2 are the results of the treatment of the industrial cracking furnace.

[0047] Example 1

[0048] Set the solid content to 20%, SiO 2 / Al 2 O 3 =8, aluminosilicate sol with a pH of 3~4 is diluted with water to SiO with an oxide mass concentration of 1% 2 -Al 2 O 3 Sol aqueous solution. The device is a 60,000-ton / year ethylene SRT-IV (HC) industrial cracking furnace, which is divided into six groups of feeds, and three waste heat boilers are connected in parallel. The furnace tubes in the radiant section of the cracking furnace are arranged along the axial direction at intervals. The twisted piece tube made integrally with the furnace tube, the twisted piece is twisted by 180°, and the distance between two adjacent twisted pieces is 15 pitches; during the hot standby after the cracking furnace is scorched, the outlet temperature of the cracking furnace is 700 ~850℃, under 0.4Mpa operating pressure, the diluted SiO 2 -Al 2 O 3 The sol aqueous solution...

Embodiment 2

[0050] Set the solid content to 20%, SiO 2 / Al 2 O 3 =8, aluminosilicate sol with a pH of 3~4 is diluted with water to SiO with an oxide mass concentration of 2% 2 -Al 2 O 3 Sol aqueous solution. The device is a 30,000-ton / year ethylene GK-V cracking furnace, which is divided into four groups of feeds. There are two waste heat boilers. The radiant section of the cracking furnace is spaced apart in the form of twisted fin tubes. The twisted fins are twisted. 180°, the distance between two adjacent twisted pieces is 20 pitches; during the hot standby after the scorching of the cracking furnace, the outlet temperature of the cracking furnace is 700~850℃. Under the operating pressure of 0.3Mpa, it will dilute Good SiO 2 -Al 2 O 3 The sol aqueous solution is injected from the cross section of the cracking furnace with the carrier gas water vapor (10kg / h), in which SiO 2 / Al 2 O 3 The molar ratio is 8:1, the injection volume is 1.5kg / h, and the injection time is 2 hours. SiO 2 -Al 2 O 3...

Embodiment 3

[0055] To simulate the SRT-III cracking furnace, using the method of the present invention, three twisted sheet tubes are added to the radiant section of the furnace tube. When the outlet temperature of the cracking furnace is 800°C, the SiO 2 A neutral silica sol with a mass concentration of 20% and a pH of 6.5 to 7.5 is diluted with water into pure oxide SiO with a mass concentration of 0.5% 2 The sol aqueous solution is injected from the cross section of the cracking furnace, the injection rate is 200g / h, the injection time is 1 hour, and the SiO 2 The sol forms a ceramic film layer on the inner wall of the cracking furnace tube, which can inhibit the coking and carburization of the furnace tube. After the cracking furnace tube is treated with the above method, steam cracking is carried out with naphtha as the raw material. Its physical properties are: distillation range 48~211℃, specific gravity D 15.6 0.7287g / ml, sulfur content of 165PPM; cracking conditions: cracking tempera...

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Abstract

The invention relates to a method for suppressing coking and carburizing of hydrocarbon steam cracking furnaces, which comprises the following steps: arranging at least one segment of heat transfer enhancement furnace pipe in the furnace pipe of radiation section of the cracking furnace, and preprocessing the hydrocarbon steam cracking furnace by using a sol composition during heat reserve period of the cracking furnace, wherein the sol composition contains at least one selected from Si sol, Al sol and Zr sol, and the mass concentration of pure oxide in the sol composition is 0.1 to 10% the weight of the sol composition. The method provided by the invention has the advantages of low cost, simple operation, environment friendliness, and no influence on downstream system, and can significantly prolong the service life and the operation cycle of the cracking furnace on the basis of effectively suppressing coking and carburizing of the cracking furnace pipe, thus improving output of ethylene products, etc. and improving the economic benefit of an ethylene plant.

Description

Technical field [0001] The invention relates to a method for inhibiting coking and carburization of a hydrocarbon steam cracking furnace in the petrochemical field. Background technique [0002] In the thermal cracking method to produce ethylene, the cracking furnace is the most critical core equipment, and about 60% of the energy consumption of ethylene production is consumed in the cracking furnace. The cracking furnace tube is the component with the highest operating temperature in the ethylene production device. The cracking reaction of hydrocarbons is carried out in the furnace tube. Due to secondary reactions such as polymerization and condensation, coke will inevitably be generated on the inner wall of the cracking furnace tube and the inner wall of the quenching boiler tube. dirt. Coking increases the thermal resistance of the tube wall, reduces the heat transfer coefficient, increases the wall temperature and causes local overheating; coking increases the energy consumpt...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C10G9/16C10G9/20C10G9/36
Inventor 王红霞王国清陈硕戴伟张利军
Owner CHINA PETROLEUM & CHEM CORP
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