| As we all know, o-chlorobenzonic aldehyde is an important intermediate in the organic synthesis. It is valuably applied in the production of the medicine, agrochemical and dyestuff. As the demand in its market continuously enlarge, and particularly export the abroad , now lots of foreign companies are longing for acquiring the goods of o-chlorobenzonic aldehyde. China is a main exported country of o-chlorobenzonic aldehyde.Up to the present, there are about dozens of producing crafts inside and outside. This text has analyzed the weakness and advantage towards every kind of the methods, and selected the local and current method of chloride hydrolyzing. We are researching on the reformation of this method, intending at further declining the cost, increasing product quantity, reducing contamination to the environment, and adequately using the equipments of the production. I think it is an ideally green producing method which has contained the foreground of industrial development.The Creative points of the text: . 1 .Using the following craft to further declining the cost, increasing product quantity:In the chlorination process we must strictly control the formation of o-chloride benzonic trichloride ( content ≤ 1.11%)s, increase the rectification, and separation process of the chlorination, in order to get the highly pure o-chloride benzonic dichloride (content ≥ 96.6%)to hydrolyzation. The o-benzyl chloride and o-chlorobenzyl chloride of the rectification will return to the inside of original chlorination system to acquire the biggest limit of using the raw material o-chlorotoluene. So we have further declining the cost, increasing the quantity of o-chlorobenzonic aldehyde. 2.Chose reasonable catalyzing conditions, an ideally green producing methodThe chlorination reaction use the light to catalyze chlorination, and it is better than using the chemical catalyst, also avoids the strong oxidation of the chemical catalyst and the possibility of easily causing the safe trouble, forming seriously contamination. I think it is an ideally green producing method.3.Chose the reasonable chlorination temperature, the hydrolyzation temperature, the vacuum of rectification, availably control the content of vice- product, and increase the product's quantity:According to a series of comparison experiment, we make selection of the chlorination temperature around 120℃, the hydrolyzation temperature between 100℃-120℃, the vacuum of rectification under -0.098 MPa, and the water content below 0.05%, as far as possible not implying the metal ions. So that the effect is ideal and we can availably control the proceeding of the vice- reaction with the producing of polymer- tar, make the synthesis more reasonable.4.Make detail experiments of the reaction of chlorination, the rectification of the chlorination, the hydrolyzation, the method of intermediate controlling of the rectification of raw o-chlorobenzonic aldehyde.Because of this craft's characteristics, the strong causticity of the medium of chlorin, currently in my country we still have no appropriate instrument to watch the on-line process, and it cause the on-line analysis very difficult. So we take the samples timely andus GC to make analysis, and we find it is a better intermediate controlling and analyzing idea.Summary:Comparing to old crafts, in this new craft the raw material o-chlorotoluene was saved about 0.30 kg/ kg, chlorine gas was saved 0.40 kg/ kg, but the pure degree of product however be increased from 97.5% -98.5%( old crafts) to 98.5% - 99.5%( this new craft).Outlook:The success of this synthesizing method can develop 1000 - 5000 t/a production equipments, and also can improve the current craft of chlorination and hydrolyzation, with further lower cost, and increase the product quantity, reduce the let of waste water, and gain considerable economic benefits and social benefit.Moreover, in the new method we have to make further research on new ,more appropriate catalyst and how to regenerate the catalyst.
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