Process for advanced treatment of waste alkali in hydrogen sulfide removal

Abstract

The invention relates to a process for advanced treatment of waste alkali in hydrogen sulfide removal, belonging to the field of environmental protection in chemical industry. The process provided by the invention improves the effect of the oxidation reaction, improves the air lifting effect of the heavy hydrocarbons in the alkali and removes the stoppage phenomenon of the sieve shaped oxidation reactor. The process uses the deep liquid level reactor composed of a sieve plate and a down comer to oxidize the waste alkali of hydrogen sulfide removals, improves the gas-liquid mass transfer and reaction driving force through the reversed contacting of the gas-liquid, and obviously improves the oxidation effect of the alkali and the air lifting effect of the volatile organic materials; for waste alkali in hydrogen sulfide removal that the COD is 30,000 to 50,000 ppm, the deprivation rate is more than 98%. The specially designed down comer removes the collection of the solid suspension at the tray and overcomes the congestion phenomenon during the process. The process is suitable for advanced innocent treatment of waste alkali of pyrolysis gas in refinery, catalytic hydrogenation desulfurization tail gas and various sulfureted hydrogen containing tail gases after NaOH or Na2CO3 solution absorbes.

Description

technical field [0001] The invention relates to a new process and oxidation reaction equipment for advanced treatment of hydrogen sulfide waste alkali liquor. The process can be used for deep oxidation of inorganic sulfide in waste caustic liquor and high-efficiency gas stripping of volatile organic compounds after hydrogen sulfide in oil refinery and / or natural gas is absorbed and treated by caustic liquor. It belongs to the field of chemical environmental protection technology. Background technique [0002] In the pyrolysis gas or gasoline / diesel catalytic hydrogenation section of the refinery, a large amount of hydrogen sulfide (H 2 S) Exhaust gas, due to the high toxicity of hydrogen sulfide, cannot be directly discharged into the atmosphere. These tail gases are usually lye (Na 2 CO 3 or NaOH) for absorption treatment, that is, converting hydrogen sulfide into Na through chemical absorption 2 S is removed from the exhaust. The waste lye after absorption treatment ...

AI Technical Summary

Problems solved by technology

This treatment technology has the following disadvantages: (1) because the superficial velocity of the liquid in the reactor is very low, it is far from being able to carry a small amount of solid particles (mainly suspended solids and crystals of lye) in the tower from the top out, thereby causing reactor tray sieve hole and mixer clogging, it is necessary to regularly disassemble the tower and remove slag, which affects normal production; (2) Na in the lye 2 The oxidation effect of S is poor; (3) the hot air has a poor effect on the gas stripping of dissolved hydrocarbons in the waste lye, so that the COD concentration of the lye after treatment is still above 5000ppm, which cannot be discharged up to the standard; (4) the top of the tower lacks air The odor is large, the concentration of volatile organic compounds is high, and there is a problem of excessive emission

Images