RU2434048C2 - Procedure for preparation of hydroxi-methyl derivatives of brown coal fulvic acids - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: procedure for preparation of hydroxi-methyl derivatives of fulvic acids consists in transition of brown coal crumbled to dimension of particles 500 mcm into water dissolved salts of high molecular compounds. Further, it is transited into high molecular organic acids consisting of constituent non-soluble in water in form of hydro-gels and constituent in form of paste soluble in water. Fulvic acids are extracted from paste by extraction with isopropyl alcohol. Fulvic acids are transformed into hydroxi-methyl derivatives of fulvic acids under effect of formaldehyde.

EFFECT: production of more reactive hydroxi-methyl derivatives of fulvic acids.

1 ex, 4 dwg

Description

The proposed patent for the invention relates to the field of non-fuel use of brown coal and can be used in the synthesis of various chemical products based on brown coal fulvic acids.

Humic and fulvic acids are a mixture of high molecular weight compounds having various functional groups that are capable of chemical interactions.

The average structural formulas of humic acids (HA) and fulvic acids (FA) are given below.

The irregular structure of the carbon skeleton of HA and FA determines the diversity and variable composition of the structural fragments that form their molecules. To describe chemical reactions involving fulvic acids, in the future we will display the FC formula with the symbol: [R _fulvo-H ].

Among the known methods for producing hydroxymethyl derivatives, a known method for producing humic formaldehyde polymers by the interaction of humic acids with formaldehyde (I.N. Ryabova, G.A. Mustafina / Modification of carbonic acids with formaldehyde // Journal of Applied Chemistry, 2003, v. 76, no. 2, p. 269-271).

Features of the prototype: humic-formaldehyde polymer in comparison with HA has a high molecular weight and low reactivity, which is why it is recommended for use as sorbents or soil builders.

The aim of the invention is to obtain a fulvic formaldehyde product with high reactivity, suitable for further use in organic syntheses.

This goal is achieved by the fact that fulvic acid isolated by extraction with isopropyl alcohol from brown coal paste interacts with formaldehyde in the reactor, forming an elastic fulvic-formaldehyde product: R _fulvo-Н + СН ₂ О → R _{fulvo-CH 2} OH.

The invention is illustrated by the technological scheme (figure 1) and a description of the process. Lignite is ground in a mechanical ball mill 1 with steel balls to a particle size of 0-500 microns.

From the ball mill, the crushed brown coal is loaded into the screw feeder of raw material 2. A 5% sodium hydroxide solution is poured into the raw material meter 3, which is then poured into the intermediate collector 4. The horizontal vibrocentrifugal mill CEM-7 5 is turned on (hereinafter referred to as activator mill 5 ) and pump 6 pump a solution of sodium hydroxide through a pipeline through an activator mill 5 ("Mills and mechanochemical activators". Promotional brochure of the Institute of Solid State Chemistry and Mechanochemistry SB RAS).

When the activator mill 5 is turned on, a screw feeder for feed 2 is turned on and finely ground coal is introduced into the sodium hydroxide solution. In the mill activator 5 they are mixed and at the same time additional grinding of coal. After all the coal from the dispenser enters the activator mill 5, the coal suspension is pumped through the activator mill 5 for a certain time until the maximum conversion of brown coal to water-soluble salts of high molecular weight compounds occurs. As the process ends, the activator 5 is stopped and the finished suspension of water-soluble salts of macromolecular compounds with residual brown coal from the collector 4 is pumped by pump 7 through the control filter 9 into the receiving collector 12. The brown coal slurry that has not passed through the control filter 9 is poured into the collector 8, from where, as accumulations are directed to a precipitation-filtering centrifuge 10, where water-soluble salts of macromolecular compounds are separated from the residual brown coal, which, as it accumulates in the collector 11, They are re-milled into an intermediate tank 4. From the tank 12, water-soluble salts of macromolecular compounds are pumped by pump 13 into a tank 15, where, using a 10% hydrochloric acid solution supplied from measuring unit 14, water-soluble salts of macromolecular compounds are transferred at pH 2 to free acids , some of which are soluble in water (fulvic acids), and the other part is not soluble in water (humic acids). In the collection 16, sedimentation and separation of free acids into two layers takes place, which are finally separated in a precipitation-filtering centrifuge 17. The water-insoluble substance in the form of acidic hydrogels of high molecular weight humic acids is discharged into the collection 18 for storage and further processing, and the soluble aqueous component is less high molecular weight fulvic acids are sent to a measuring device 19, from where they are transferred to a distillation cube 21 for distillation of hydrochloric acid. The distillation cube 21 is equipped with a heater and a water cooler 22. As hydrochloric acid is distilled off into the receiver 23, the distillation cube 21 is cooled and a certain volume of isopropyl alcohol is charged from the measurer 20, mixed and passed through the filter filter 24 to the isopropyl extract collector 25. Extraction with isopropyl alcohol is carried out several times until deep extraction of fulvic acids. An isopropyl extract of fulvic acids from collector 25 is transferred to a reactor 28, from which a certain volume of isopropyl alcohol is distilled off through a water cooler 29 to a collector 30. Formaldehyde is poured from a measurer 27 into a reactor 28 and the hydroxymethyl derivatives of fulvic acids are synthesized with stirring. At the end of the synthesis, excess solvent is distilled off from the reaction mass, after which the mobile reaction mass is cooled, and then the obtained elastic polymer product is extruded from the reactor 28 onto a suction filter 31 and then used in various organic syntheses.

An example of obtaining hydroxymethyl derivatives of fulvic acids from brown coal.

For the synthesis of hydroxymethyl derivatives of fulvic acids, a commercial sample of brown coal of grade 2B of the Kaychaksky open pit mine (Barandatskoye field, Kuzbass) is used.

Characteristics of the original brown coal: Moisture Content, W ^a ,% by mass 5,0 Ash content, A ^d ,% by weight 9.8 Higher calorific value, Qs ^daf , kcal / kg 4700 Volatiles yield, V ^daf , by weight 45.8 Carbon, C ^daf 72.9 Hydrogen, H ^daf 5.3

Fulvic acids obtained by the above technology in an amount of 50 ml (30% solution in isopropyl alcohol) are mixed in a reactor with 90 ml (30% aqueous formaldehyde solution) and at a reaction temperature of 60 ° C with stirring for 1 hour turn into hydroxymethyl derivatives of fulvic acids. At the end of the synthesis, excess solvent is distilled off from the reaction mass, after which the mobile reaction mass is cooled, and then the obtained elastic polymer product is squeezed out of the reactor onto a suction filter and then used in various organic syntheses.

To assess the quality of the obtained product, IR spectra of the initial and modified fulvic acids are recorded (FIG. 2).

For hydroxymethyl derivatives of fulvic acids, a new absorption band of 3391 cm ^{–1 appeared} , corresponding to stretching vibrations of hydroxyl groups. The bifurcated intense absorption band in the region of 2976-2891 cm ^-1 corresponds to stretching vibrations of aliphatic groups (CH ₂ ) and (CH ₃ ). A less intense bifurcated band in the region of 1470-1391 cm ^-1 also belongs to the aliphatic groups (CH ₂ ) and (CH ₃ ).

In the interaction of hydroxymethyl derivatives of fulvic acids with diisocyanate, hard polyurethane was obtained, the infrared spectrum of which is shown in Fig. 3. For this polymer, a new intense narrow band appeared in the region of 1677 cm ^–1 , which is associated with stretching vibrations (CN) and deformation vibrations (NH) of amide groups.

Figure 4 shows electronic photographs of modified fulvic acids. It can be seen that the structures of the polymers differ markedly.

Claims (1)

A method of preparing hydroxymethyl derivatives of brown coal fulvic acids, characterized in that the brown coal, crushed to a particle size of less than 500 microns, is converted into water-soluble salts of high molecular weight compounds, and then into high molecular weight organic acids, consisting of a water-insoluble component in the form of hydrogels and a soluble component in the form of a paste from which fulvic acids are isolated by isopropyl alcohol, which, under the action of formaldehyde, are converted into more reactive hydroxymetics derivatives of fulvic acids.

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