Temperature control system and temperature control method for active coke adsorption tower

Abstract

The invention belongs to the field of chemical engineering, and particularly discloses a temperature control system and a temperature control method for an active coke adsorption tower. The temperature control system for the active coke adsorption tower comprises the active coke adsorption tower, a purified flue gas cooler and a chimney, wherein an inlet gas chamber, an outlet gas chamber, a first-stage adsorption bed layer, a second-stage adsorption bed layer and an interstage gas chamber are sequentially arranged in the activated coke adsorption tower from bottom to top; the inlet gas chamber is connected with a to-be-purified flue gas feeding pipeline; the outlet gas chamber is connected with a purified flue gas discharging pipeline; the purified flue gas discharging pipeline is dividedinto two branches, the first branch pipeline is connected with the chimney, and the second branch pipeline is connected with an inlet of the purified flue gas cooler; and an outlet of the purified flue gas cooler is connected with the interstage gas chamber and the inlet gas chamber. According to the invention, purified flue gas is circulated back into the activated coke adsorption tower, so thetemperature of flue gas at the inlet of the activated coke adsorption tower and the temperature rise of a bed layer of the adsorption tower are effectively controlled; and meanwhile, the oxygen content and the water content of the flue gas are kept basically unchanged, and the safe and stable operation of the activated coke adsorption tower is ensured.

Description

technical field [0001] The invention belongs to the field of chemical industry, and more specifically relates to a temperature control system and a temperature control method for an activated coke adsorption tower. Background technique [0002] Activated coke dry purification technology began to be applied industrially in the 1980s. It has outstanding advantages such as high desulfurization efficiency, no water consumption for reaction, no waste water and residue discharge, and no equipment corrosion problems. With the increasing requirements of environmental protection, this technology has attracted more and more attention and has been widely used. Applying activated coke dry purification technology to catalytic cracking unit can effectively remove SO in regeneration flue gas 2 / SO 3 , while for NO x , particles and VOCs also have a synergistic removal effect, combined with the upstream SCR and downstream bag filter, the entire purification system can purify the regenera...

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Problems solved by technology

In addition, medium-temperature SCR (320-400°C) process is usually used for denitrification of regenerated flue gas in catalytic cracking units. Since the active components of SCR are mainly V 2 o 5 , the regenerated flue gas will have 1% to 2% SO after passing through the SCR 2 converted to SO 3 , resulting in SO in the regeneration flue gas 3 high content

Moreover, since the NH of the SCR 3 Escape at 2~3mg / Nm 3 , will bring the following two problems: one is the NH 3 with SO 3 The reaction produces very viscous NH 4 HSO 4 , will adhere to the catalyst fine powder in the flue gas, causing the economizer to quickly accumulate salt and block, NH 4 HSO 4 The formation temperature of SO is usually 190~240℃; the second is higher SO 3 The acid dew point of the flue gas is higher due to the content of the acid, which brings corrosion and other problems to the downstream equipment

Among them, setting the flue gas heater to SO 3 The concentration is high and there is a small amount of NH 3 When the flue gas with particulate matter is directly cooled, problems such as dew point corrosion, salt formation, and dust accumulation may occur; water spray cooling may cause the spray water to not be completely gasified, so that SO may be dissolved in the mist droplets 3 , bring corrosion problems to the flue and downstream equipment, increase water consumption at the same time, and the water content in the flue gas will further increase, which may affect the denitrification performance of the activated coke; mixing cold air to cool down will greatly increase the oxygen content of the flue gas, so that The oxygen content in the flue gas is higher than the reference oxygen content, and the requirements for the downstream activated coke dry purification facilities are higher, and the air mixed in the flue gas will directly dilute the concentration of pollutants in the flue gas. With the continuous improvement of environmental protection standards, it is possible in the future Similar measures that mix air directly into the flue gas will gradually be restricted

[0008] There are two main measures to control the bed temperature rise of the activated coke adsorption tower. One is to reduce the SO in the flue gas to be purified. 2 concentration, but this measure will limit the activated coke dry purification process in the treatment of high SO 2 The second is to reduce the temperature of the flue gas to be purified and reduce the heat released by the oxidation of the active coke bed to control the temperature rise of the bed

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