8 results about "Oleum" patented technology

The application discloses a multi-stage fuming sulfuric acid absorption tower and a process method for absorbing sulfur trioxide by using the fuming sulfuric acid absorption tower. The multi-stage fuming sulfuric acid absorption tower comprises a primary absorption assembly and a secondary absorption assembly. The primary absorption assembly is provided with a first containing cavity. A first acid distributor is arranged in the first containing cavity and is arranged close to the upper wall surface of the first containing cavity and used for spraying acid liquid into the first containing cavity. The primary absorption assembly is provided with a flue gas inlet communicated with the first containing cavity. The secondary absorption assembly is arranged above the primary absorption assembly. The secondary absorption assembly is provided with a second containing cavity. The second containing cavity is communicated with the first containing cavity and used for receiving flue gas from the first containing cavity. A second acid distributor is arranged close to the upper wall surface of the second containing cavity and used for spraying acid liquid into the second containing cavity. The upper end of the secondary absorption assembly is provided with a flue gas outlet communicated with the second containing cavity. In this way, the sulfur trioxide absorption rate can be improved, and the product purity can be ensured.

This invention relates to the field of flame retardant chemical synthesis technology, and discloses ethylene bis(tetrabromophthalimide) and its preparation method and applications. The method includes reacting phthalic anhydride and ethylenediamine in an aqueous medium at a controlled mass ratio of 3.0-5.5:1 to obtain an intermediate; reacting the intermediate with bromine in a fuming sulfuric acid medium, controlling the dropping temperature at 45-60℃ and the holding temperature at 130-150℃; and washing the reaction product followed by high-temperature heat treatment at 150-220℃ to constant weight. This invention effectively inhibits residual active amino groups and organic carbonization by strictly controlling the intermediate synthesis ratio and the temperature range of the bromination reaction. By utilizing high-temperature heat treatment, it thoroughly removes deep-seated acidic volatiles that cannot be removed by conventional drying, solving the problems of yellowing appearance, poor heat resistance, and easy corrosion of processing equipment in existing products. It is applicable to the field of flame-retardant engineering plastics.

The present application belongs to the field of boron trifluoride production, and relates to a method for preparing boron trifluoride and its complex by continuous flow reaction. The method comprises the following steps: uniformly mixing boric acid with concentrated sulfuric acid, then adding oleum or continuously introducing sulfur trioxide gas to obtain an oleum solution of boric acid; introducing the obtained solution and anhydrous hydrogen fluoride gas into a continuous flow reactor at a uniform speed to obtain boron trifluoride gas; purifying and removing impurities from the boron trifluoride gas generated in the reaction; continuously introducing the purified boron trifluoride gas into a complexing solvent for a complexing reaction to obtain a boron trifluoride complex. The method uses a continuous flow reactor to react anhydrous hydrogen fluoride with the oleum solution of boric acid, so that the raw materials can be continuously and uniformly mixed, the reaction is rapid and complete, the process conditions are simplified, the sulfuric acid waste liquid can be recycled after treatment, and the method has economic advantages and process innovation, and is suitable for industrial production.

This invention proposes an environmentally friendly and efficient method for preparing aminosulfonic acid, belonging to the field of chemical technology. It includes: (1) sulfonation reaction; (2) crude product filtration; (3) dissolution and crystallization; and (4) drying and packaging. The reaction process of this invention features mild reaction conditions, short reaction time, and a yield exceeding 97%. The process, using fuming sulfuric acid and urea at a lower temperature, significantly reduces polluting components in the waste gas. It has many advantages, including simple operation, low cost, high yield, and greater environmental friendliness.

This invention discloses a method for producing chromatographic grade cyclohexane, comprising the following steps: A) Taking cyclohexane as raw material, adding fuming sulfuric acid to the cyclohexane raw material, stirring and allowing it to stand, and then separating the cyclohexane; B) Adding pure water to the cyclohexane obtained in step A, stirring and allowing it to stand, and then separating the cyclohexane; C) Adding activated alumina and 10X molecular sieve to the cyclohexane obtained in step B, stirring and allowing it to stand, and then filtering; D) Distilling the cyclohexane obtained in step C to obtain chromatographic grade cyclohexane. This invention uses fuming sulfuric acid to remove impurities from the cyclohexane raw material, then washes it directly with pure water, followed by adsorption filtration using molecular sieves and alumina, and finally distillation to obtain chromatographic grade cyclohexane with optical properties meeting market customer requirements. The preparation process of this invention is not complex, the consumption of auxiliary agents is low, and the cost is within a controllable range, achieving the goal of industrial production of chromatographic grade cyclohexane with high optical properties.

The application relates to the field of flame-retardant materials, and particularly discloses a preparation process of ethylene bis-tetrabromophthalimide with high thermal stability; the preparation process of ethylene bis-tetrabromophthalimide with high thermal stability comprises the following specific steps: phenolic anhydride and ethylenediamine are mixed in water, heated to react, centrifuged, dried to obtain an intermediate; the intermediate is mixed with bromine, fuming sulfuric acid and a catalyst to obtain a reaction solution, heated to react, deacidified, washed with water and dried to prepare ethylene bis-tetrabromophthalimide; the catalyst is a composite of ferric chloride and iodine; the ethylene bis-tetrabromophthalimide intermediate is synthesized by phenolic anhydride and ethylenediamine, and then bromination reaction is carried out, so that the instantaneous intense heat release caused by excessively high local bromine concentration is reduced, the escape of HBr and the loss of bromine are reduced, and the purity of the product is improved.

The application provides a method for continuously producing AMPS, and belongs to the technical field of sulfonic acid; the production method comprises a sulfonation reaction, an addition reaction and separation and refining; the method for the sulfonation reaction is that qualified acrylonitrile and oleum are continuously input into a pipeline mixer to obtain a mixture; 75-85% of the mixture is continuously input into a reaction kettle; the remaining mixture circulates in the pipeline mixer; meanwhile, acrylonitrile is continuously input into the reaction kettle; the liquid level in the reaction kettle continuously rises; the mixture overflows from an upper overflow port and is input into a reaction kettle 2; the method for continuously producing AMPS provided by the application can obtain AMPS with a purity of 99.22-99.37% and a yield of 89.91-91.27%.

The application relates to the technical field of drilling fluid treating agents, and discloses a high-temperature-resistant sulfonated asphalt for drilling fluid and a preparation method thereof, the preparation method being as follows: asphalt is crushed, melted at 140-160 DEG C, then cooled to 120-130 DEG C, fuming sulfuric acid is added dropwise, after the dropwise addition is completed, stirring reaction is carried out for 2-3 h, the temperature is continuously lowered to 90-100 DEG C, deionized water is added, a sodium hydroxide solution with a mass fraction of 20% is used to adjust the pH of the system to 8-9, then sulfobetaine type zwitterions and modified nano silicon dioxide are added into the system, high-speed stirring is carried out at 1000-1500 rpm for 30-60 min, drying is carried out, crushing is carried out, and the high-temperature-resistant sulfonated asphalt for drilling fluid is obtained. The high-temperature-resistant sulfonated asphalt for drilling fluid prepared by the application has good high-temperature resistance and shale inhibition performance.