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Section 6. Chemistry
Ravshanov Dilshod, Tashkent chemical-technological institute, researcher
Kadirov Yuldoshxon, Tashkent chemical-technological institute, professor E-mail: [email protected]
PERFECTION OF TECHNOLOGY OF PROCESSING OF COTTON SOAPSTOCKS
Abstract: It can be seen that the process of processing soapstoks in general and cotton in particular has not been sufficiently studied. In addition, in the present study, new approaches have been taken to studies of the process of neutral fat digestion, containing in a co-abbreviated fat mixture, by the stepwise application of concentrated sulfuric acid and catalysts. To determine the influence of dilution of soapstock on the process of decomposition of soapstock on the process of decomposition of its soap part, experiments were carried out with varying the amount of water in the 0; 50; 75 and 100% of the total weight of the soapstock. The optimal regimes of the non-reactive cleavage of the cotton saopstock fat mixture are established: the amount of reaction water in the ratio of fat: water 1: 1.
Keywords: technology, soapstocks, physicochemical parameters, sulfuric acid, decomposition-splitting, Quality indicators.
One of the important stages in the new technol- with water [3; 4] and others with such a treatment
ogy of processing soapstocks is the stage of sulfuric acid treatment of soapstock, because the choice of optimal conditions for this process depends on: a) the completeness of the decomposition of the soap portion of the soapstock: b) the maximum removal of non-fat substances from the fat mixture; (coloring agents, phosphatides, etc.); c) the normal flow of subsequent processes (splitting, distillation); d) improvement of the quality of fatty acids and glycerin.
In the literature there are contradictory information about the process of decomposition-splitting of soapstocks in general and sulfuric acid treatment of soapstocks in particular, for example, in some sources [1; 3] it is indicated that the best decomposition-splitting occurs at a temperature of 80-90°, even 100 °C, and others [2] give preference to the conduct of the decomposition-splitting process at a temperature of 60-70 °C. In addition, some believe that sulfuric acid treatment should be carried out without additional dilution of the initial soapstock
are recommended to conduct with liquefied (water) soapstock [2], in order to improve the flow of decomposition of the soap portion of the soapstock. The question of the behavior of non-fatty substances in the sulfuric acid treatment of soapstocks and the degree of their removal from the fat mixture is completely unclear.
Finally, there is no reduction in the consumption of concentrated sulfuric acid necessary for the stepwise decomposition-splitting of the soap portion of the cotton soapstock, its neutral fat and the non-fat complex.
It can be seen that the process of processing soapstoks in general and cotton in particular has not been sufficiently studied. Therefore, we carried out research to find conditions for the decomposition-splitting of cotton soapstocks and the production of co-abdominal fat and glycerin waters, with a minimum content of foreign impurities of a group of non-fatty substances. In addition, in the present study, new approaches have been taken
to studies of the process of neutral fat digestion, containing in a co-abbreviated fat mixture, by the stepwise application of concentrated sulfuric acid and catalysts.
During the day of conducting laboratory experiments, the cotton soapstocks of JSC "Kokand-fat-oil" were initially used with the following indicators (Table 1).
Table 1. - Physicochemical parameters of cotton soapstock
Image numbers Composition of cott ton soapstock in %
Total content of fatty acids neutral fat soap non-fatty substances humidity Color
1. 58.45 21.55 31.15 5.48 24.05 Dark
2. 55.60 24.01 37.94 8.05 26.81 Dark brown
3. 59.24 18.95 33.51 6.84 25.41 Dark brown
4. 61.48 20.44 33.14 5.48 24.88 Dark brown
The consumption of sulfuric acid for the decomposition-splitting of soapstock varied widely, depending on the amount of soap and neutral fat contained in it.
In this connection, the content of soap, neutral fat and non-fatty substances was determined in each batch of soapstock.
The decomposition of cotton soapstocks was carried out on a laboratory installation. Stirring was carried out by a mechanical stirrer making 100-150 rpm; the reaction mass was heated in a water bath. After the introduction of the components of the reaction medium, the process lasted for 2 hours, and then the mass was left for stratification, which resulted in three layers: the bottom was concentrated in the water layer, the upper layer of fat, and at the interface between the aqueous and fat phases, an emulsion layer (a resinous layer of non-fatty substances)
To determine the optimum conditions for carrying out the process of sulfuric acid treatment of sopstocks of various compositions, the following effects were investigated:
- additionally introduced water for liquefaction of soapstock;
- excess of concentrated sulfuric acid;
- temperature of the reaction mass;
- is the amount of catalyst.
To determine the influence of dilution of soapstock on the process of decomposition of soapstock
on the process of decomposition of its soap part, experiments were carried out with varying the amount of water in the 0; 50; 75 and 100% of the total weight of the soapstock.
The amount of concentrated sulfuric acid necessary for the decomposition of the soap portion of the soapstock, the maintenance of the corresponding strongly acidic reaction medium, the partial cleavage of the neutral fat, and the decomposition-splitting of the non-fatty substances of the soapstock was calculated on the basis of the content of soap in copulation with 30% excess.
The experimental conditions and results are shown in the (Table 2).
The data of (Table 2) shows that, when the water (distilled) is introduced into the reaction mass in the ratio-co-liquor: water = 1:1, 1:0.75, the decomposition proceeds normally, the mixture separation takes of a very long time (experiment 1-5). The intermediate layer (emulsion and resinous substances) in all experiments has a brown color.
In experiments 8-10 (without introducing additional water into the soap), the process of mixing the mass was difficult.
In experiments 6, 7 (the ratio of co-liquids: water 2:1) plus added 3 g of sulfuric acid dramatically improved the decomposition process, it passed normally, the corresponding phases were clearly separated in a short time. The intermediate layer (the emulsion layer)
p NO oo On y> to r I
o o o o o o o o o o o o o o o o o o o o soapstock Amount g
to o C>J o o C>J o o to o to o C>J o o o o o o o o o water
34.0+3.0 34.0+3.0 34.0+3.0 34.0+3.0 34.0+3.0 34.0 34.0 34.0 34.0 34.0 sulfuric acid with 30% excess
input of concentrated sulfuric acid Duration a min.
to o to O to to to O to o to to o to o to o The process of decomposition-splitting
90-92 90-93 90-93 90-92 90-91 90-92 90-93 90-95 88-90 88-92 The temperature of the decomposition process, °C
lh 50m lh 50m to to o o to to Sludge of the reaction mass in hours
i i Poor separation NO oo to C>J oo C>J to o Number of intermediate layer (layer, emulsion) g
i i Undefined C>J o o C>J o o to to to to to oo to to CM Output of the soap oil mixture
i i i 92.0 92.7 69.0 70.0 76.0 76.0 76.0 ON
1.65 1.65 1.68 1.50 1.59 0.71 0.63 0.58 0.51 0.68 Containing sulfuric acid in acidic waters,%
i i i i i The rapid seeding was parted. i i i Avery long time Separation of the reaction mixture
i i i i Color dark brown layer more dense i i i i Brown color Characteristics of the intermediate layer (emulsion)
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was more dense and in a smaller amount, compared with previous experiments. The color of the intermediate layer is dark brown. Therefore, it was decided to carry out subsequent experiments according to the experimental regime No. 6, No. 7, but with a variation in the excess of the input concentrated sulfuric acid.
Thus, we studied the process ofupgrading cotton soapstock by an improved method that allows us to save scarce caustic soda while manufacturing fatty acids from sapstocks and to exclude the use oftable salt. Without reactive cleavage of the soap-oil fat mixture was carried out on a specially made 1.4-liter cameral autoclave. Splitting of the fat mixture was conducted in two phases with a duration of 6 hours each at a temperature of 225 ° C and a pressure of 2.2-2.4 MPa (22-24 kg / cm2).
Cotton soapstock fat mixture before loading into the autoclave was thoroughly washed with hot water to remove traces of sulfuric acid. In this case, of course, partially washed and sulfate. The presence of sulfuric acid in the fat is not allowed, since it destroys the effect on the material of the autoclave. Distilled water was used for both phases during the cleavage.
In the first and second phase of the cleavage, the amount of fat mixture of distilled water and pressure in the autoclave was constant, respectively, 450 and 440 g, respectively; 450 and 400 g; 22 MPa, and when studying the effect of the amount of reactive water on the cleavage process, these amounts were equal to 450 and 440 g; 390 and 340g; 22 MPa.
The results of the study of the process of the non-reactive cleavage of cotton sapostock fat mixture are presented in (Tables 2 and 3).
At the end of the first phase of the cleavage, the mass was set aside. After the first glycerin water was drained, the second phase of decomposition was carried out. The separation of aqueous phases occurred normally without the formation of an emulsion.
From the data of (Table 2)shows that when the ratio of the fat blend to water phase I at 1:1, in phase II of 1:0.9 and with the duration of the degradation process until 6 watch is best depth equal splitting 93.4-94.1%
(experiments 1 / 61-2 / 61). Subsequent reduction of the duration of the cleavage process up to 4 hours (I phase), 3:00 (II phase) already affected the depth cleavage soapstock fat, reducing it to 91.1%. Further decrease in the duration of the cleavage process up to 3 hours (phase I) and 3 hours (II phase) still lowered the depth of fat splitting to 84.0%.
Also, the acid numbers from 183.1 mg KOH to 179.6 mg KOH decreased. After the first phase of cleavage, the content of glycerin in water was 6.57.4%, after the second phase 2.0-4.1%.
Table 4 shows the results of a study of the effect of the amount of introduced reaction water on the process of the reactive cleavage of the cotton copolymer mixture.
In order to clarify the possibility of concentration of the first glycerin water in the case of no-reactive cleavage, an attempt was made to reduce the ratio of the amount of water introduced to the fat of 0.87:1 in the first cleavage phase and 0.77: 1 in the second cleavage phase. As shown by the data obtained, the decrease in the amount ofwater affected the decrease in the depth of splitting of the sap grease mixture both in the 1st phase and in the second cleavage phase (the cleavage depth after the II phase fluctuated within 85.4-89.0% at acidic number of crude fatty acids in the range of 176.0-181.0 mg KOH, although the concentration of glycerol waters increased somewhat) after the II phase - up to 4.3%.
It follows that when splitting the co-paste fats of cotton soapstock in a non-reactive way, it is not recommended to reduce the amounts of reactive water below the ratio of fat: water 1: 1 and 1: 0.9.
For purification and processing, glycerin water, obtained after both cleavage phases, was mixed and processed into glycerol. It was purified by neutralization with milk of lime. Glycerin water from all experiments obtained by the method of hydrolysis of a cotton soap fat mixture by a reactive method (using sulfuric acid, a sulfonol catalyst) and without a reactive method was purified, neutralized, evaporated and analyzed.
Table 3.- Effect of the duration of the process on the depth of the split of the cotton fat mixture
№ of experiment I Phase of the cleavage II Phase of the cleavage
Continuing resident, process, h Temperature of the mass, ОС Glycerin water Continu-ingprocess, h Temperature of the mass, °C Glycerin water The splitting depth% CN crude oil. Acidity, mg KOH
Color Concentration, % Color Concentration,%
1/61 6 220 yellow, green 7.2 4 220 yellow 4.0 93.4 183.1
2/61 6 219 - 7.4 4 220 - 4.1 94.1 183.6
3/61 4 218 - 6.8 3 220 yellow 2.6 91.1 181.5
4/61 4 220 yellow 6.9 3 220 - 2.8 90.8 180.8
5/61 3 220 yellow 6.5 3 220 yellow 2.0 85.1 180.0
6/61 3 220 yellow 6.6 3 220 yellow 2.3 84.0 179.6
Table 4,- Effect of reactive amounts of water on the process of splitting the fat blend of cotton
I Phase of the cleavage II Phase of the cleavag e
№ of experiment Con- Tem- Pres- Glycerin water Tem- Pres- Glycerin water CN
tinuin-gresi-dent. process, h perature of the mass, С sure, in an autoclave, MPa Color Concentration^ Fat mixture, g Distilled water, g Con-tinu-ingpro- cess, h perature of the mass, С sure, in an autoclave, MPa Color Concentration^ The splitting depth% crude oil. Acidity, mg KOH
7/61 6 220 22 yellow 7.1 440 340 4 218 22 yellow 4.3 89.0 180.5
8/61 6 220 22 - 7.0 440 340 4 219 22 - 4.2 88.4 181.0
9/61 4 220 22 yellow 6.5 440 340 3 220 22 - 3.8 85.4 176.0
10/61 4 220 22 yellow 6.3 440 340 3 220 22 - 3.6 85.4 176.0
11/61 3 219 22 yellow 6.1 435 340 3 218 22 - 3.1 86.1 177.5
12/61 3 219 22 yellow 6.8 440 340 3 219 22 - 3.0 85.5 176.1
When the mixture of glycerin waters was settled, some quantities of fatty acids appeared on their surface and were removed by depletion.
To neutralize water containing sulfuric acid and free fatty acids, it was treated with milk of lime.
Lime milk was prepared by quenching calcined lime, as well as diluting the calcareous creeper with tap water.
Neutralization of acidic glycerol waters after the reactive cleavage of the co-abbreviated fat mixture was carried out with lime milk by stirring with a mechanical stirrer making 65 rpm. At a temperature of70-83 ° C - until a slightly alkaline reaction (by titration).Neu-tralization is completed, if 3-5 liters of 0.01 N hydrochloric acid are consumed while titrating 25mm of neutralized glycerin water. This corresponds to an excess of alkali 0.003-0.005% in terms of calcium oxide.
The neutralized glycerol water from all the experiments was then defended, a layer of floating foam, calcium soaps separated, filtered and allowed to evaporate in vacuum at a residual pressure of 10 mm Hg. During the evaporation, sodium sulfate was separated in the flask, from which glycerin was separated by decantation. After cooling at room temperature, some more sulfate was separated from the glycerin, after which all the resulting glycerol batches were filtered and then analyzed.
The glycerin waters of the non-reactive cleavage of co-abstained fatty mixtures contained less organic and mineral impurities, they were neutralized with lime milk, defended, filtered and evaporated in vacuum. During the evaporation of sulfate, the separation was significantly less than when working with glycerol water after cleavage with sulfuric acid and sulphonol.
Since the glycerol water produced by splitting cotton sapstock fat mixtures turned out to be dirtier than the glycerin water obtained in the cleavage of pure triglycerides, it was necessary to develop special processing regimes for treating these contaminated glycerol waters. For this purpose, the following technological regimes for treating co-pumped glycerol waters are proposed.
1. Primary treatment
The combined glycerol waters after the I and II cleavage phases at 80-84 C were neutralized with lime milk until a slightly alkaline reaction, then filtered and evaporated in vacuum with periodic separation of sodium sulfate. However, the resulting glycerin was of low quality and therefore subjected to additional secondary processing.
2. Secondary treatment
Glycerin water after the primary treatment was again neutralized with lime milk, filtration and subsequent treatment at a temperature of80-82 ° C and agitation with alumina. At the end of the introduction of alumina, glycerol water was mixed for another 1.5-2 hours then defended and filtered.
The excess of alumina was qualitatively determined by adding a small amount of alumina solution to the filtered sample of glycerol water. The absence of a deposit of alumina hydrate indicates that alumina is added to glycerol water in sufficient quantity.
The filtered weakly acidic waters were neutralized with lime, they were defended for another 1.5 hours. and then concentrated by evaporation to 25-30%. The semi-evaporated products were treated with activated carbon at 55-60 ° C and stirred by a mechanical stirrer for 2-2.5 hours. The amount of activated carbon varied widely and was determined depending on the color of the glycerol waters obtained after purification and the quality parameters of the finished glycerin. The purified glycerol water after filtration was finally evaporated in vacuum to a concentration of about 88%.
The results of the studies are presented in (Tables 5 and 6).
In all experiments, the yield of glycerin is about 7% of the weight of neutral fat contained in the cotton soapstock.
In order to study the quality of the glycerol obtained, depending on the methods of treating glycerol waters, separate experiments were performed for the non-reactive cleavage ofcotton saphonic fatty mixtures.
Section 6. Chemistry
Table 5.- Quality indicators of the obtained batches of glycerol depending on the methods of treatment of glycerol waters
Name of glycerol waters after splitting Glycerin water after primary processing, filtration and partial evaporation Glycerin after the secondary water treatment, filtration and residue
№ of ex. Concentration of glycerol waters to processing Concen-tration% Content,% Concentra-tion% Content,%
Non volatile organic remnant ashes Non volatile organic remnant ashes
64 9.2 15-20 11.4-11.8 12.5-13.01 83.04 3.85-3.90 3.7-3.8
65 9.6 21.5 12.5-12.7 13.15-13.41 87.10 4.15-4.16 3.91-4.01
66 9.5 19-20 11.1-11.4 12.1-12.3 84.15 4.20-4.48 4.04-4.21
67 10.4 19.5 10.4-11.5 11.0-12.1 83.50 3.95-3.99 3.95-4.31
68 11.0 24.0 11.0-11.1 12.1-12.5 85.10 4.45-4.80 4.11-4.40
69 10.1 20.0 12.0-12.1 11.5-12.5 86.15 4.50-5.01 4.10-4.50
70 9.8 19.0 12.0-12.8 12.0-13.0 84.25 4.14-4.28 4.08-4.15
Glycerin water had a concentration in the range of 6.81-7.4% after the first phase of the cleavage. Glycerin water after the I phase and 3.31-4.50% after the II phase of the cleavage. Glycerin water after the appropriate primary treatment and filtration (see above) were light yellow, and after final filtration and evaporation - light brown. The qualitative characteristics of the products obtained during the splitting and the composition of the treated glycerol waters are shown in (Table 5).
The data in (Table 5) show that, with a non-reactive cleavage of a cotton soapostock fat mixture, the depth of the fatty mixture is achieved to 94.18% and the glycerol water concentration is up to 7.4%.
The optimal regimes of the non-reactive cleavage of the cotton saopstock fat mixture are established:
The glycerin obtained after filtration, secondary processing and evaporation had a concentration of 88.97% and contained a non-volatile organic residue up to 3.65% and ash to 1.49%. According to these indicators, the glycerin obtained corresponded to the requirements of the standard for commercial grade 2 glycerin.
Thus, the expediency of the non-reactive cleavage (hydrolysis) of cotton saphonic fatty mixtures and the production of crude fatty acids and glycerol is shown. At the same time, the depth splitting of the fat mixture 93,4-94,1%, acid number of crude fatty acids 181,5-183,6mg KOH corresponding to the standard TU Uz86-6-98.
- the amount of reaction water in the ratio of fat: water 1: 1;
Table 6.- Qualitative indicators of glycerin
Soapstock fat, g Depth splitting Concentration glycerol water Glycerol obtained after filtration, secondary processing of glycine. the water of their residue
Phase I Phase II After Phase I After Phase II After Phase I After Phase II Glycerol at recalculation 88%-percent Con tent,%
Non-volatile organic remnant ashes
450 425 89.75 93.85 6.81 3.31 86.97 2.56 1.04
450 420 88.70 94.01 7.40 3.41 88.5 2.57 1.49
450 430 88.75 93.15 6.95 4.11 88.0 3.59 1.14
450 425 89.40 94.18 7.01 4.50 88.6 3.65 1.11
- The temperature of the process of splitting of - The pressure in the autoclave is about 2.4 MPa the I phase - 6h., Phase II - 4h. (24 kgf / cm2).
References:
1. Rukovodstvo po tehnologii polucheniya i pererabotki rastitel'nyih masel i zhirov. VNIIZH,- 1961.- T
3.- 67 s.
2. Kasparov G. N. i dr. "Nepreryivnyiy process razlozheniya soapstokov sernoy kislotoy" MZHP,- 1966.-No. 7.- 14 s.
3. RacionaTnyie metodyi ochistki glicerinovyih vod v proizvodstve glicerina - M. CINTI Pisheprom,-1968.- S. 32-34.
4. Mad T. K. Continous Acidulution of Soapstock and Recovery ofAsid oil J. A. O. Ch, Soc.,- 1983.- No. 5.- P. 1008-1011.
