Environment-friendly synthetic method for hydroxylamine salt

Abstract

The invention belongs to the field of organic chemical industry and provides an environment-friendly synthetic method for hydroxylamine salt. Aliphatic ketone, ammonia and hydrogen peroxide are adopted as raw materials and catalyzed through a nano-pore skeleton bi-metal hybrid ammoximation catalyst to prepare ketoxime in an ammoximation mode, the ketoxime directly reacts with inorganic acid in a hydrolysis mode after being desolvated and deaminized to prepare the hydroxylamine salt, aliphatic ketone can be reused, the effective utilization rate of hydrogen peroxide is larger than or equal to 97%, and the product purity is larger than or equal to 99%. The environment-friendly synthetic method for the hydroxylamine salt is suitable for large-scale industrial production.

Description

technical field [0001] A green synthesis method of hydroxylamine salt. The invention relates to a green synthesis method of hydroxylamine salt, in particular to ammoximation and hydrolysis reactions. technical background [0002] There are three main synthetic methods for hydroxylamine salts. The first is nitromethane and acid hydrolysis, the second is traditional acetone oximation, and the third is acid-catalyzed hydrolysis of ketoxime. [0003] The first nitromethane acid hydrolysis method is the main method for industrial production of hydroxylamine salt. This method is as introduced by Cheng Yonggang ("Fire and Explosives", No. 4, pp. 10-12, December 1993) and Tang Zhenqiu ("Hunan Chemical Industry", No. 4, 1990) and other introductions. At first, nitromethane must be produced, and then nitromethane Hydrolyze under acidic conditions to prepare hydroxylamine hydrochloride. The preparation methods of nitromethane include natural gas method, chloroacetic acid method, hal...

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Problems solved by technology

[0008] Compared with cyclohexanone, small molecular aliphatic ketones such as acetone and methyl ethyl ketone have smaller molecules, and are easily oxidized by titanium-silicon molecular sieves during long-term operation of industrial devices, thereby affecting catalyst activity. In 2012, Zhang Shengjian et al. reported TS-1 titanium-silicon After molecular sieves are used continuously for 7 times, the conversion rate of ketones drops below 50% (Chin.J.Org.Chem.2012, 32, 786-789), which is not conducive to industrial production

In 2008, RajaRobert et al. reported a transition metal-containing aluminophosphate redox catalyst, which used oxygen as an oxidant to perform ammoximation reaction on cyclohexanone. The conversion rate of ketone was 56-97%, and the selectivity of oxime was 84-100%, but catalyst preparation and ammoximation process conditions are complicated, which is not conducive to industrialization (WO2009 / 004342, WO2010079324)

In 2002, HerwigJuergen et al. used titanium siliceous rock as catalyst, ammonium salt of inorganic acid or carboxylic acid as cocatalyst, and solvent partially miscible or immiscible with water as solvent, adding interphase contact agent, two-phase ammonia oxime chemical reaction, complex reaction system, low conversion rate and selectivity (CN02152443.2, WO2005063691)

In 2010, Zeng Yuanhui used organic-inorganic composite heteropoly acid salts as catalysts to ammoximate cyclohexanone. The conversion rate of ketone was ≥90%, and the yield was ≥80%, but the selectivity was only 80%, and the recovery rate of the catalyst was low. Gao (Master's thesis of Xiangtan University "Preparation of organic-inorganic composite heteropolyacid salts and its catalytic cyclohexanone oxime ammoximation reaction")

In 2014, XiaolingXue et al. reported a polyoxometalate K 6 PW 9 V3O 40 4H 2 O catalyst, under 25 DEG C with isopropanol as solvent condition, aliphatic ketone ammoximation, although the selectivity of oxime is greater than 99%, but the preparation of catalyst is complicated, it is difficult to separate from the product, and the conversion rate is only 80-87% ( Catalysis Communications, 33(2013), 61-65)

The cyclohexanone oxime used in this process has a slow hydrolysis rate during the hydrolysis process. Due to the high boiling point of cyclohexanone, it cannot be removed in time, the conversion rate is low, and the separation cost is high.

And the process adopts a batch production process. The catalyst TS-1 needs to be separated every time it is used, washed with alcohol and water, and then activated at high temperature. The operation is complicated and the operation cost is high (CN201310351567.9)

Above-mentioned several methods are all unfavorable for industrialized production owing to factors such as environmental protection, economic benefit

[0013] In summary, the nitromethane and acid hydrolysis method and the traditional acetone oximation method produce a large amount of waste gas, waste salt and waste water due to the high toxicity of raw materials and intermediate products, complicated process

However, the reported ketoxime hydrochloric acid hydrolysis methods basically have the disadvantages of using ketoxime with high cost as raw material, failing to realize the recycling of materials and complicated process operations; and the microporous titanium such as TS-1 required for the synthesis of ketoxime Silica molecular sieve has small pores (pore size ≤ 2nm), easy to block, and short single operation cycle, which limits its industrial application

The hybridization of non-silicon elements based on MCM-41 and SBA-15 mesoporous and composite materials is mainly used in olefin epoxidation, etc., and there are not many studies on double metal doping in transition metals, let alone Ammoximation Reports Applied to Ketones

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