High-temperature dechlorination agent and preparation method thereof

Abstract

The invention discloses a high-temperature dechlorination agent and a preparation method thereof. The high-temperature dechlorination agent is suitable for an environment at a temperature of 200 to 500 DEG C. The high-temperature dechlorination agent is prepared from 20 to 30% of Na2CO3, 20 to 30% of NaOH, 20 to 40% of bentonite, 2 to 10% of polyvinyl alcohol and 1 to 2% of (NH4)2CO3 by mixing. The high-temperature dechlorination agent has the advantages that component compatibility is good so that all technical indexes are high; through the high-temperature dechlorination agent, chloride content of raw material oil is reduced to content below 0.45mg / L from content above 10mg / L; a dechlorination ratio reaches above 95%; a chloride capacity reaches 53%; all the technical indexes are superior to technical indexes of congeneric products; raw material oil feeding requirements from a device can be satisfied; and the solution of device chlorine-corrosion problems is promoted.

Description

technical field [0001] The invention relates to a high-temperature dechlorination agent mainly composed of sodium carbonate, bentonite and sodium hydroxide, which is mainly used for high-temperature (200-500° C.) dechlorination in a prehydrogenation system of a continuous reforming unit. Background technique [0002] The main source of chlorine in feedstock oil of Lanzhou Petrochemical Company’s continuous reforming unit is that the use of organic chlorides in the oil recovery process increases the chlorine content in feedstock oil to 3-10mg / L, making chlorine in the feedstock oil of the pre-hydrogenation system of the unit The compound content is as high as 10mg / L or more. These chlorides are converted into inorganic hydrogen chloride after being catalytically converted in the pre-hydrogenation system along with the raw material oil. Hydrogen chloride is a corrosive medium with strong oxidizing properties. The harm to the prehydrogenation system of the continuous reforming...

AI Technical Summary

Problems solved by technology

Chinese patent CN1064099A discloses a dechlorination agent that uses alkali metals and alkaline earth metals as dechlorination active components and uses natural inorganic clay as a binder. When the reaction temperature is lower than 280°C, the hydrogen chloride content after dechlorination can be reduced to 0.50mg / L or less; Chinese patent CN1079415A discloses a dechlorination agent using alumina and alkali metal and alkaline earth metal carbonates, which can reduce the hydrogen chloride content in raw materials to below 0.50mg / L; Chinese patent CN1178133A uses carbonic acid Sodium, calcium carbonate and magnesium oxide are the active components, and the natural inorganic clay is used as the carrier. When the reaction temperature is lower than 480°C, the chlorine in the raw material can be reduced to below 0.1mg / L, but the chlorine capacity can only reach 30%. ; Chinese patent CN1539921A discloses a multifunctional dechlorination agent composed of molecular sieves and active substances. : 5 ~ 20%, alkali metal-alkaline earth metal oxide: 30 ~ 90%, synergist: 1 ~ 5%, can work in a wide temperature range (100 ~ 550 ℃), but only the raw materials Chlorine is reduced to about 1mg / L

In short, most of these known dechlorination agents are prepared by impregnating less than 17% active components on porous supports, and the chlorine capacity is generally not high, so higher dechlorination effects cannot be achieved, and usually only Can be used at lower temperatures (≤500°C)

[0004] The dechlorination agents originally used in the continuous reforming unit of the refinery of Lanzhou Petrochemical Company include: NC-2 (produced by Nanjing University of Chemical Technology) dechlorination agent, KT-405 dechlorination agent (developed and produced by the Kunshan Joint Venture of Northwest Chemical Research Institute), etc. However, the effect of these dechlorination agents in this device shows that the dechlorination efficiency is low, and it cannot fully meet the requirements of the device for the chloride content in the raw oil.

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