Method for processing sulfur-containing waste lye

Technical Field

The invention relates to a sulfur-containing waste lye treatment method, a catalytic oxidation processing method, in particular to a supported cobalt phthalocyanine catalytic oxidative desulfurization method.

Background Art

In the production of the petroleum chemical, alkali cleaning technology widely used in the production process, such as liquid hydrocarbon alkali refining process, the alkaline cleaning process of gasoline, diesel oil and ethylene alkali wash process alkali wash process of pyrolysis gas. Most the amine washes at home and abroad with the alkali in the process of getting rid of pyrolysis gas H₂ S, CO₂, COS and other acidic gas. Formed after alkali wash process the waste lye containing a relatively high concentration of sulfide, ammonia, phenol at the same time, pollutants such as cyanide and oil, has a strong odor, can not be directly discharged into the sewage treatment plant, need for pretreatment.

The treatment of the waste lye start earlier study abroad, on in the sixties the United States have begun to explore the use of the wet-oxidation process, that is, the high-temperature and high-pressure chemical oxidation of the sulfide and mercaptans. Although the process is complete, but capital costs and operating costs are very high. Japan's major use of carbon dioxide and sulfuric acid neutralized, recoverable elemental sulfur, but in and after the waste liquid still need to be addressed. The current method for treatment of waste lye at home and abroad can be roughly divided into three categories: neutralization method, oxidation method and comprehensive utilization.

The catalytic oxidation is to blast air in the alkali toward waste at the same time, into a kind of active catalyst, under the action of a catalyst, the oxidation of sodium sulfide and sodium sulfate into sodium thiosulfate. This kind of method as with direct oxidation method, there is no secondary pollution caused by the exhaust gas.

yu Zhengzhe and others ("north-east power institute Journal" 2003 years (4): 24-27) based on the processing advanced oxidation technology research of the waste lye ethylene production. The process is the homogeneous chemical catalytic oxidation technology to processing ethylene cracking waste lye, the reaction temperature is 40 the [...] , the reaction time is more than 90 min, air water ratio (aeration amount) for 75      1, Mn²⁺ initial concentration is 15 mg ·]^-1 under the condition of, S^2- the conversion rate can be up to 96% more, BOD₅/CODcr of the pretreatment value can be 0.21 to 0.50. In the process, however, there is a need to consume the oxidizing agent, the drawback of the large processing cost.

CN1111582C has introduced a kind of processing oil products in petroleum refining industry method of alkali refining waste lye, in other words the the 100-190 [...] and 0.3-3.0 MPa pressure, the waste lye contact with an oxygen-containing gas, as molecular oxygen from being oxidized in the waste lye inorganic sulfides and organic sulfide, wherein the oxygen-containing gas in waste lye inorganic sulfides and organic sulfide is oxidized to sulfate the desired amount of the 100%-180%, so that the sulfur into the sulfate or thiosulfate, and then the oxidized waste lye step-down cooling, its recovery wherein the phenol and naphthenic acid, for waste water obtained by intermittent activated sludge process, enter the batch activated sludge process waste water in the biological reaction tank and controlling the content of the salt 30 g/l the following. This kind of method has caused by high-temperature and high-pressure caused by the high energy consumption, the great shortcoming of the operation cost.

Now many introducing device adopts the wet air oxidation process processing ethylene sulfur-containing waste lye, that this method, however, the harsh requirements on equipment, difficulty of operation, high energy consumption, low capacity. The catalytic oxidation process can be applied to various nature of the sulfur-containing waste water, which is particularly suitable for small water quantity sodium salt sulfur-containing waste water. And the processing efficiency is high, low energy consumption, is the use of a catalyst, as a result of the widespread attention. At the domestic and foreign literature: preparing a supported cobalt phthalocyanine for mercaptan removal of many research, preparing a supported cobalt phthalocyanine used for catalytic oxidation of the sulfur-containing waste lye studies have not been reported.

wang Huiguo and others ("petroleum refining and chemical" 2001 year (1) 49-53: "model mercaptan oxidation dual-function catalyst research CoSPc/Mg (Al) O") in the laboratory, magnesium-aluminum oxide solid solution in the solid alkali is mg (Al) O carrier, load four preparation of sulfonated cobalt phthalocyanine (CoSPc) double-function catalyst, the mercaptan oxidation reaction has good catalytic activity. The catalyst is used for the jet fuel deordorization test, the initial activity is superior to the activated carbon load sulfonated cobalt phthalocyanine catalyst, but its alkali center is easy to be CO₂, H₂ O and an acidic substance poisoning and deactivation.

CN   1074313C, bangs ultra research such as a supported cobalt phthalocyanine mercaptan oxidation catalyst. The catalyst is supported on a solid alkaline oxide surface, with negative ion group is sulfonate phthalocyanine is cobalt phthalocyanine drill or salt of a carboxylic acid with a quaternary ammonium salt having a cation group of cobalt phthalocyanine the ion pair complex formed. The catalyst is used for the mercaptan oxidation or oil products deodorizing. The mercaptan oxidation reaction is used for adding liquid alkali is not used, and at the same time having a high catalytic activity and stability.

CN1164592C in oxidative desulfurization catalyst preparation of cobalt phthalocyanine sulfonate, in removing sulfur-containing waste water is used as organic sulfides and inorganic sulfide oxidative desulfurization catalyst, application method is applied directly to the cobalt phthalocyanine in the sulfur-containing waste lye, this kind of traditional application method has the problem of run off effluent drills along with phthalocyanine.

Content of the invention

The purpose of this invention is to overcome the deficiency of the prior art, provides a supported cobalt phthalocyanine catalytic oxidative desulfurization processing method for sulfur-containing waste lye.

Sulfur-containing waste lye in general the majority of the sulphide in the form of sodium salt, also a small amount of mercaptan, sulfur etherses substance, when after fully contacting with the compressed air, can be gas-liquid two-phase oxidation reaction, but the reaction time is relatively long, if the waste water is oxidized to adding a certain amount of cobalt phthalocyanine compound as a catalyst, then the reaction time can be greatly shortened.

Cobalt phthalocyanine compound for the oxidative desulfurization reaction with catalytic role in the principle of cobalt phthalocyanine with very high oxygen velocity, oxygen cobalt phthalocyanine compound after the reductive substance foregather, will release of live to oxygen, so that the reducing material is oxidized, its activity can be repeatedly regenerated in the oxygen supply is restored, this for its industrial application provide a reliable guarantee.

Traditional application method is applied directly to the cobalt phthalocyanine in the sulfur-containing waste lye, presence of phthalocyanine cobalt along with the loss of water, it will, on the one hand an increase in the cost of the handle, on the other hand, the cobalt ion is possible to cause the loss of water outlet in the water environment, cause secondary pollution.

The present invention provides a processing method for sulfur-containing waste lye, in other words: A) by using the impregnation process in the cobalt phthalocyanine sulfonate load on the active carbon carrier preparing activated carbon supported cobalt phthalocyanine catalyst; B) the supported cobalt phthalocyanine catalyst added in reactor; C) sulfur-containing waste lye respectively with an oxygen-containing gas into the reactor, the catalyst bed of catalytic oxidative desulfurization process is completed.

The said cobalt phthalocyanine sulfonate can be according to CN   1164592C prepared by the method. Cobalt phthalocyanine sulfonate can be through dipping process load of the activated carbon carrier after activation (cobalt phthalocyanine sulfonate with activated carbon weight ratio of 1 the [...] the 50-1 [...] 500), dried preparation leaves the activated charcoal supported cobalt phthalocyanine sulfonate catalyst.

The method of the present invention is preferably used for the tower reactor of the reactor. An oxygen-containing gas is preferably compressed air. The catalytic oxidation reaction is preferably the normal temperature and the normal pressure conditions.

The method of the present invention sulfur-containing waste lye and an oxygen-containing gas is preferably countercurrent contact of the catalyst bed, catalytic oxidation of desulfurization process is completed.

Because the activated carbon is a very important and widely applied to the metal catalyst carrier, as a kind of adsorption catalytic material, the chemical, petroleum, light industry, food, environmental protection, and widely applied to the field, is the performance of the surface by its pore structure and the chemical nature of the decision. It has a high specific surface area, of the surface of the porous structure and special chemical nature, can be the active ingredient in the catalyst is fully dispersed and adjuvant. Therefore, in the method of the invention uses activated carbon as the catalyst carrier, the method of the present invention the raw material is easy to obtain, the cost is low, the high-efficiency catalytic characteristics.

Cobalt phthalocyanine catalytic oxidation reaction of sodium sulfide to a subject. So that the concentration of sodium sulphide removal rate in a linear correlation with the sodium sulfide. That is, the higher the concentration of the reactant, the higher the reaction rate. Because activated carbon having a strong adsorption effect, an activated carbon supported cobalt phthalocyanine has good adsorption performance, the catalyst surface and the periphery of the of the sodium sulfide concentration higher than the concentration of the liquid phase, the catalytic oxidation rate.

Pure cobalt phthalocyanine catalytic oxidation of the sodium sulfide, the reactant concentration is high to a certain degree, the reaction rate is increased is not obvious. This is because oxygen more difficult to dissolve in water, so the reaction is dissolved in the water concentration of the oxygen in the constraints, that is, in the size of the mass transfer rate. The activated carbon also has the role of oxygen, thus can solve the above-mentioned raising the reaction rate by shui Zhongyang concentration restricted.

In addition pure activated carbon adsorption can not realize the degradation of the pollutants, can only realize the enrichment of the pollutants, and the absorption of the activated carbon need of the regenerating, operation immodesty also will result in atmospheric pollution. Activated carbon supported cobalt phthalocyanine, cobalt phthalocyanine has the catalytic oxidative desulfurization activity, can make the absorption of sulfide and other pollutants to be oxidized rapidly, thereby achieving the role of the pollutant removal, the activated carbon would not need to be regenerated. Activated carbon supported cobalt phthalocyanine catalyst, because of not only retains the good adsorptivity of activated carbon, and with high load of the catalytic oxidative desulfurization activity of cobalt phthalocyanine, generated in the reaction system the adsorption-reaction-desorpt integrated state, the catalytic reaction is, the promotion of the catalytic oxidation rate.

This invention adopts the low priced activated carbon as a catalyst carrier, phthalocyanine the cobalt is solid is contained in the inner portion and the surface of the activated carbon, preparing the supported catalyst has the advantages of simple preparation process, catalytic efficiency, and the like. By adopting the method of the invention for treating the sulfur-containing waste lye, not only can prevent the cobalt phthalocyanine directly into secondary pollution caused by the water, but also can improve its processing sulfur-containing desulfurizing effect of the waste lye, the results from the contrast can be seen the embodiment of: activated carbon supported cobalt phthalocyanine catalytic oxidation activity is high. On the other hand, the process is simple, the safety is high.

The current as the state of the importance to the environmental protection, the requirements of environmental protection are increasingly high. Preparing a supported cobalt phthalocyanine catalyst is used for the catalytic oxidation of sulfur-containing waste lye, not only conforms to the requirements of the environmental protection, but also can improve the catalytic oxidative desulfurization of the catalyst capacity, can satisfy the governance of the ever-increasing requirements of the source.