CS209994B1 - Method of processing the formates - Google Patents

Abstract

The invention provides a method of processing formates from aldehydes and / or ketones in alkaline environment. The corresponding formate is treated by decomposition a suitable inorganic acid, e.g. nitric acid, thereby releasing it formic acid and form e.g. calcium formate. The reaction mixture is essential it is concentrated and distilled off formic acid. this the distillate is further processed to concentrated formic acid or is boiled to go to the main process to neutralize of the reaction solution from the formaldehyde reaction with a higher aldehyde or ketone. The residual concentrate may be preferably processed in the production of fertilizer or use directly ’, eg in ροϊ’ηοhh · ·

Description

(54) Method of processing ravens

The invention provides a process for treating ants from the reaction of formaldehyde with aldehydes and / or ketones in an alkaline medium.

The appropriate formate is digested with a suitable inorganic acid, e.g. nitric acid, thereby releasing formic acid and forming e.g. calcium formate. The reaction mixture is substantially concentrated and at the same time the formic acid is distilled off. This distillate is either further processed to concentrated formic acid or can be returned to the main process to neutralize the reaction solution from the reaction of formaldehyde with a higher aldehyde or ketonor. The residual concentrate may advantageously be processed in the manufacture of the combined fertilizer or directly used, e.g. in ροϊ’ηοhospodárs tve ·

209 994

209 994

It is an object of the present invention to provide a process for treating ants of formaldehyde and aldehydes and / or ketones in an alkaline medium.

Higher alcohols, e.g. pentaerythritol, trimethylolpropane, neopentyl glycol and others are commonly produced by reacting formaldehyde with aldehyde and / or ketones, e.g. with acetaldehyde, n-butyraldehyde and others. The reaction takes place in an aqueous alkaline medium, the alkali metal or alkaline earth hydroxide, e.g. sodium or calcium hydroxide. With regard to the process conditions of the reaction, a small excess of this alkaline component is added to the reaction mixture as compared to the theoretically required amount, generally up to 20%. sulfuric acid, formic, carbon dioxide, etc. ·

As a by-product of the ongoing reactions, formic acid ion is formed which forms the appropriate formate with the alkaline component present, e.g. sodium or calcium. According to the process chosen, the formate is then decomposed or recovered as a by-product in the form of a solid, suspension or solution during further processing.

The economic use of this by-product is a major problem. It can be used directly as a silage preservative, converted to hydrosulfite and processed in paper making or used as one of the raw materials in formic acid production. However, processing of the reaction mixture resulting from the reaction of a strong acid to formate is a considerable problem.

If sulfuric acid is used for the decomposition according to the commonly used procedure, a considerable volume of sulphate is obtained after separation of water and formic acid, e.g. Calcium, which does not provide recovery and is a nuisance waste. If according to MS. of the author's certificate no. We decompose the formate by the action of nitric, phosphoric acid or mixtures thereof to obtain the byproduct of the corresponding nitrate or phosphate in the form of a solid phase, encounter considerable handling difficulties requiring a large number of operations and relatively complex equipment (filtration or centrifugation, drying, transport). solids, etc.).

According to the present invention, a process for treating formates formed from the reaction of formaldehyde with aldehydes and / or ketones having 2 to 5 carbon atoms in an alkaline medium to form water-soluble calcium salts is carried out by concentrating the reaction mixture by evaporating water and formic acid to inorganic salt content. % to 98 wt. and to a content of formic acid in the liquid phase of 1 to 48% by weight, preferably 1 to 10% by weight. the resulting concentrate is added to 1 reaction mixture to prepare a mixture of ammonium nitrate with calcium nitrate and / or a combined fertilizer such that the ratio of the dry matter of the concentrate to the dry matter of the reaction mixture is 0.01 to 0.1 prior to concentration and / or granulation of the reaction mixture or in a known manner, preferably for a liquid fertilizer, and part or all of the distillate, preferably after further concentration

209 994 to at least 60 $ wt. formic acid, in addition to neutralizing the reaction mixture from the reaction of formaldehyde with aldehydes and / or ketones in an amount corresponding to 0.8 to 1.2 times the stoichiometric limit of the neutralization reaction of formic acid and alkali present in the reaction mixture prior to neutralization, or is treated in a known manner, for example, to concentrated formic acid.

Such a process has a number of substantial advantages over the prior art. By avoiding the thickening process up to the separate solid phase recovery stage, the process is greatly simplified, without compromising product quality. On the contrary, after the reaction mixture has been concentrated to a depth such that it contains the inorganic salts still partially or completely dissolved, we avoid both the troublesome conveying and scavenging processes, and we also leave them in solution or suspension! yet some formic acid, which, when used in agriculture, has further beneficial effects. Addition of formic acid significantly improves the preservation and disinfection properties of the by-product, e.g. when used as fertilizer, fertilizer additive or other agricultural purpose.

By suitably selecting the formic acid content of the batch, the concentration of the acid obtained can be determined in a wide range, from very dilute to concentrated, to the corresponding azeotropic mixture. If necessary, it is possible to include a 'next technological step and get' formic acid at virtually any concentration.

The formic acid thus obtained can be used either directly as a neutralizing agent to terminate the reaction in the production of the higher alcohol, or further processed for other purposes.

In this way, the necessary neutralizing acid is obtained by treating the intermediate itself, the reaction mixture does not introduce a foreign substance (such as using sulfuric acid), and the technical and economic parameters of such a process are much more favorable with respect to better utilization of raw materials and energy. !.

Example 1

To the suspension! 50 parts of calcium formate, obtained as a byproduct in the production of pentaerythritol, 50 parts of water and 2 parts of urea added to suppress the oxidative effect of nitric acid are added with stirring and cooling, successively 53.5 parts of 65% nitric acid. The reaction mixture is concentrated by evaporation to give 63 parts by weight of a distillate having a HCOOH concentration of 35% by weight. and 109 parts of a residue containing 55 wt. calcium nitrate and 7.3 formic acid. The distillate is added to the reaction mixture from the reaction of formaldehyde with aoetaldehyde in an aqueous medium having a Ca (OH) ₂ concentration of 1% by weight. so as to neutralize the entire amount of Ca (OH) _{2 present} , i.e. at a rate of 3.7 parts of distillate per 100 parts of reaction mixture.

209 994

The calcium nitrate concentrate is added to the reaction mixture to produce the C 33 flask in such a ratio that the total calcium nitrate content of the finished product is 6 wt.

Example 2

To the batch of 50 parts of calcium formate, 50 parts of 35% formic acid and 2 parts of urea, 53.5 parts of 65% nitric acid are successively fed and stirred. The reaction mixture is concentrated at 50 kPa to 65 parts of a 58% by weight HCOOH distillate. and 100 parts concentrate containing 60% calcium nitrate and 9.5 HCOOH. The distillate is further used to produce concentrated formic acid, the concentrate being processed as a liquid fertilizer.

Example 3

The calcium formate obtained as a by-product in the preparation of pentaerythritol is treated as in Example 1. The distillate is concentrated to a formic acid content of 60 to 65% by weight. and added to the reaction mixture to produce pentaerythritol so as to obtain a final pH of the mixture in the range of 5.0 to 6.0. The calcium nitrate concentrate is added to the reaction mixture to produce the combined fertilizer in an amount such that the total nitrogen content of the mixture is 10 to 13% by weight.

Claims (1)

OBJECT OF THE INVENTION Process for the treatment of formates resulting from the reaction of formaldehyde with aldehydes and / or ketones having 2 to 5 carbon atoms in an alkaline medium forming water-soluble calcium salts, characterized in that the reaction mixture is concentrated by evaporating water and formic acid to an inorganic salt content of 40 to 98 fy wt. and to a formic acid content in the liquid phase of 1 to 48% by weight, preferably 1 to 10% by weight, the resulting concentrate is added to the reaction mixture for the preparation of a mixture of ammonium nitrate and calcium nitrate and / or combined fertilizer so that to the dry weight of the reaction mixture is 0.01 to 0.1, before concentration and / or granulation of the reaction mixture, or is worked up in a known manner, preferably into a liquid fertilizer, and part or all of the distillate, preferably after further concentration to 60% wt. of formic acid, leads to neutralization of the reaction mixture from the reaction of formaldehyde with aldehydes and / or ketones in an amount corresponding to 0.8 to 1.2 times the stoichiometric ratio of the neutralization reaction of formic acid and alkali present in the reaction mixture before. neutralizing it, or treating it in a known manner, for example, with concentrated, formic acid.