CS261464B1 - Process for preparing monoacylglycerols - Google Patents

Abstract

The solution relates to food production emulsifiers such as monoacylglycerols aliphatic monocarboxylic acids catalytic Elycerolysis of fats at 230 ° C and deactivation catalyst (CaO) defined the amount of orthophosphoric acid in the reaction temperature, and agaration of the deactivated catalyst blasting at 120 to 125 ° C and isolating monoacyglycerols by molecular distillation, The method allows multiple reuse of non-responders and side-by-side glycerolysis products.

Description

The invention relates to monoacylglycerols of aliphatic monocarboxylic acids 0 ₁₂ ^C 24 * ^{Ϊ3Ϊ; 0 monoacyl 1} s ¹ y ^{cerols are} surfactants which are used as emulsifiers, especially in the food industry.

The most common industrial production of monoacylglycerols of aliphatic monocarboxylic acids is based on the glycerol fatty alcoholysis. It is a reversible reaction usually taking place at temperatures of 200 - 280 ° C or higher, mostly in the presence of a catalyst, which is an alkali metal or alkaline earth metal hydroxide or oxide. Monoacylglycerols are obtained from the reaction mixture, mostly after neutralization of the catalyst, by, for example, molecular distillation or extraction. The aim is to reuse unreacted or by-products of alcoholysis. The production processes are mostly discontinuous, but continuous processes are also described, with an emphasis on vigorous mixing of the reaction mixture.

A disadvantage of the known processes for the production of monoacylglycerols of aliphatic monocarboxylic acids is, in particular, that the neutralization of the catalyst results in a finely divided salt which is very difficult to remove, reducing the possibility of re-use of unreacted fractions and by-products of alcoholysis.

These disadvantages are eliminated by a method for producing monoglycerides of monocarboxylic acids ali fatic 0 _12-0 ^ ₂ according to the invention, wherein the oil is reacted with glycerol, the weight ratio of glycerol to fat Lu 3: 1 in the presence of 0.02 to 0.2 wt% CaO as a catalyst (based on fat), the reaction temperature being 220-250 ° C. After completion of the reaction, the calcium oxide is deactivated by a precisely defined amount of orthophosphoric acid and separated from the reaction mixture, from which monoacylglycerols are then isolated by at least two-stage molecular distillation. In the second step, the final product is obtained as a distillate containing at least 90% by weight of monoacylglycerols. The distillation residue contains at least 70% by weight of diacylglycerols

- 2,261,464, in that the deactivation of calcium oxide is carried out at a reaction temperature of 220-250 ° C by the addition of orthophosphoric acid (H 2 PO 4), with 0.7 moles of orthophosphoric acid per mole of calcium oxide being preferred, Of a concentration of 75% or more by weight. The reaction mixture is then cooled to 120-140 ° C and at this temperature, by blasting, it removes free glycerol undissolved in the fat phase and sludges containing deactivated calcium oxide in the form of orthophosphoric acid salts. The free glycerol obtained by blasting and / or molecular distillation and / or the fat fraction obtained by molecular distillation and / or the distillation residue from the preceding batch are added to the starting reaction mixture of the following batch, which reuse, preferably all of said unreacted and by-products. at least six times in a row. The glycerol of the preceding batch constitutes at most 70% by weight of the total glycerol content of the fresh reaction mixture and the fat fraction obtained in the molecular distillation and / or the distillation residue from the molecular distillation always constitutes at most 50% by weight of the total fat fraction in the fresh reaction mixture.

An advantage of the process of preparing the monoacylglycerols of the aliphatic monocarboxylic acids of the invention is that they are operated at lower temperatures, unreacted fractions and by-products can be reused, and polyglycerol formation and glycerol decomposition are reduced. This reduces the total consumption of raw materials by an average of more than 10% by weight. Due to the des-activation and removal of calcium oxide, deposits do not form on the distillation apparatus. The distillation residue from molecular distillation is itself a quality intermediate product for the preparation of food emulsifiers.

The following examples illustrate the process for preparing the monoacylglycerols of the present invention.

Example 1

A 4.5 liter lo glass flask was charged with 3 kg of a reaction mixture containing 75 parts by weight (hereinafter dw) of fully hardened tallow (hereinafter tallow) and 25 wt. d. glycerol. After the mixture was heated to 230 ° C, 0.05% by weight of calcium oxide (tallow) was added as a slurry in glycerol.

After an hour, calcium oxide was deactivated at 230 ° C by adding 75 percent orthophosphoric acid to the reaction mixture, with 0.7 mol orthophosphoric acid per mole of calcium oxide.

- 3,261,464

The reaction mixture was then cooled to 120 ° C at which temperature undissolved glycerol and sludges containing calcium phosphate deactivated by orthophosphoric acid (hereinafter referred to as sludges) were separated from the mixture in a centrifuge. The remaining reaction mixture contained 9> 4% by weight of free glycerol, 51> 4% by weight of monoacylglycerol aliphatic monocarboxylic acids (hereinafter MAG), 1.3 · 10 ^J $ by weight of calcium oxide and its color was characterized by grade 8 color scale according to ČSN 58 0101 ( hereinafter referred to as the "color scale"). Two-stage molecular distillation followed. In the first stage, the residue of free glycerol and the fat fraction (hereinafter referred to as TP) containing raonoacylglycerols, free aliphatic monocarboxylic acids and a small amount of diacylglycerols and triacylglycerols were distilled off at a temperature of 175-180 ° C. In the second step, a distillate containing 96.4% by weight MAG, 1.5% by weight ⁴ % by weight calcium oxide, 0.2% by weight glycerol was obtained at 190-200 ° C, and its color was characterized by a 4 color scale scale. The distillation residue contained 7.3% by weight of MG, 80.4% by weight of diacylglycerols (hereinafter DAG), 12.3% by weight of triacylglycerols (hereinafter TAG) and 2.3 · 10 10% by weight of calcium oxide, the color being characterized 12-color scale.

Example 2

3 kg of a reaction mixture consisting of 35-7 wt. tallow and 14 »3 wt. d. glycerol, on the one hand, all the returning portions from the previous batch treated as in Example 1, i.e. 7.1 wt. d. TP from the first stage of molecular distillation, 32.2 wt. d. distillation residue, 4.3 wt. d. centrifuge glycerol; and 7 »8 wt. d. glycerol from the first stage of molecular distillation. The reaction temperature and the deactivation temperature of the catalyst (CaO) were 220 ° C, the temperature at which the glycerol and sludge were centrifuged was 125 ° C. Otherwise, the procedure was the same as that described in Example 1. The distillate contained 94.2% (w / w) MG, 0.3% w / w. glycerol, 1.1 ♦ 10 ~ ⁴ % & * · calcium oxide, color - grade 4 color scale.

Example 3

A 3 kg reaction mixture consisting of 39.7 wt. d. tallow and 8.4 wt. d. glycerol, on the one hand, all the recoverable fractions of the preceding batch, of which:

- 4 "

261 464 processing is given in Example 2, namely 6.7 wt. d. TP from the first stage of molecular distillation, 28.6 wt. d. distillation residue, 8.3 wt. d. glycerol obtained by blasting and 7.8 wt. d. glycerol from molecular distillation. The reaction temperature and the deactivation temperature of the calcium oxide were 250 ° C, the blasting temperature was 140 ° C. Otherwise, the procedure was the same as in Example 1. The centrifugation reaction mixture contained 9.6 wt. glycerol, 51.4% -7 in wt. BG, 2.0. 10% wt. calcium oxide, color - grade 11 color measuring scale. The distillate contained 95.6 wt. MAS, 0.1 wt. glycerol, 0.7. 10% wt. calcium oxide, color - grade 4 color measuring scale. The distillation residue contained 80.3 wt% DAS, 13.9 wt%. TAS, 5.7 wt. MS and 5.1. 10 ~ ^ wt. calcium oxide, color - grade 15 color measuring scale.

Example 4

Into a 4.5 L glass flask was charged a fresh reaction mixture containing 38.2 wt. tallow and 10.1 wt. d. glycerol and, on the other hand, all the recoverable fractions of the previous batch whose treatment is given in Example 3, namely 5.5 wt. d. TP from molecular distillation, 31.3 wt. d. distillation residue, 8.1 wt. d. blasted glycerol and 6.8 wt. d. glycerol from molecular distillation. The reaction mixture was worked up as in Example 1. The distillate contained 95.1 wt. MS, 0.2% wt. glycerol and 1.3 · 10 ^ wt. calcium oxide, color - grade 4 color measuring scale.

Example 5

A fresh reaction mixture containing 40.8 wt. tallow and 10.1 wt. d. glycerol and, on the other hand, all the recoverable fractions of the preceding batch whose treatment is given in Example 4, namely 4.0 wt. d. TP from molecular distillation, 30.2 wt. d. distillation residue, 7.5 wt. d. glycerol obtained by blasting and 7.4 wt. d. glycerol from molecular distillation. The working up procedure was the same as in Example 1. The reaction mixture after centrifugation of glycerol and sludge contained 10.0 wt. glycerol, 52.2 wt. MS, 2.7 · 10 * ^% wt. the color of the calcium oxide and its color corresponded to the degree 14 of the color measuring scale. The distillate contained 94.8 wt. MS, 0.3 wt. glycerol, 1.1 · 10 "^ wt. calcium oxide, color - grade 4 color measuring scale. The distillation residue contained 72.7 wt. DAG, 17.0 wt. MAG, 10.3 wt. TAS and 1.0 · 10 calcium oxide, color - grade 17 color measuring scale.

- 5 Example 6 261 464

3 kg of reaction mixture containing 39.8 wt. d. tallow and 10.2 wt. d. fresh glycerol and any recoverable fractions from the previous batch whose treatment is given in Example 5, namely 3.7 wt. d. TP from molecular distillation, 31.4 wt. d. distillation residue, 6.9 wt. d. glycerol separated in a centrifuge and 7.9 wt. d. glycerol from molecular distillation. The working procedure was identical to that described in Example 1. The distillate contained 93.7 wt. MAG, 0.1 wt. glycerol and 1.4 · 10 wt. calcium oxide, color - grade 5 color measuring scale.

Example 7

In a 4.5 L glass flask 3 kg of reaction mixture containing 41.5 wt. d. tallow and 9.7 wt. d. glycerol, on the one hand, all the returning portions from the previous batch whose preparation is shown in Example 6, i.e. 3.0 wt. d. TP from molecular distillation, 30.5 wt. d. distillation residue, 7.5 wt. d. glycerol separated in a centrifuge and 7.7 wt. d. glycerol from molecular distillation. The working-up procedure was identical to that described in Example 1. After centrifuging the undissolved glycerol and the slurries, the reaction mixture contained 10.0 wt. glycerol, 52.0 wt. BG, 2.7 · 10 ~ ^ wt. the color of the calcium oxide and its color corresponded to the degree 7 of the color scale. The distillate contained 92.9 wt. MAG, 0.1 wt. glycerol and 1.2 · 10 * wt. calcium oxide, color - grade 5 according to the color scale. The distillation residue contained 80.0 wt. DAG,

6.6% wt. MAG, 13.4 wt. TAG and 1.6 · 10 ² % wt. calcium oxide, color - grade 18 color measuring scale.

Example 8

Preparation for quarter operation. 60 kg of reaction mixture containing 75 wt. d. tallow and 25 wt. d. glycerol. After the mixture was heated to 230 ° C, 0.05 wt. calcium oxide (based on tallow) in the form of a suspension in glycerol. After one hour, the calcium oxide was deactivated at 230 ° C by adding 70 percent orthophosphoric acid to the reaction mixture, with 0.7 mol of acid per mole of calcium oxide. The reaction mixture was then cooled to 120 ° C and at this temperature sludge and undissolved glycerol with a residual content of 0.02% by weight were separated in a LAPX 202 plate self-cleaning centrifuge. calcium oxide. The remaining reaction mixture contained 9.3 wt. free

- 6,261,464 glycerol, · 51.4 $ wt. · MG and 1.5 · 10 ”^ wt. The calcium oxide was subjected to two-stage molecular distillation under the conditions set forth in Example 1. The distillate contained 97.3% wt. MG, 0.1 $ wt. and glycerol. 1.3 · Io ^'2 *'.% wt. Calcium oxide, color - grade 4 of the color scale. The distillation residue contained 8.5 wt. MG, 79.7 wt. DAG, 10.8 wt. TAG and 2.5. 10 ~ ² # wt. Calcium oxide, color - grade 12, color scale. The recoverable fractions, i.e. the TP from the first distillation, the distillation residue, the centrifuged glycerol and the first from the first distillation, were used repeatedly as in Examples 2 to 7.

The process for the production of the monoacylglycerols of the aliphatic monocarboxylic acids according to the invention is particularly useful in the fat industry in the production of emulsifiers useful in many areas of the food industry.

Claims (2)

SUBJECT OF THE INVENTION 261 464 1. A process for producing monoglycerides aliphatic, monocarboxylic acid ^reaction ₂ ^ 0 ^ fat of glycerol at a weight ratio of fat to glycerol 3: 1, at a temperature of 220-250 0 ° using calcium oxide as a catalyst, deactivation of the catalyst and its removal from the reaction mixture together with a portion of the free glycerol, by multistage molecular distillation of the remaining reaction mixture, in which the free glycerol residue and the fatty portion containing free aliphatic monocarboxylic acids are removed and monoacylglycerols in the form of a distillate and diacylglycerols in the form of a distillation residue are obtained, by adding orthophosphoric acid to the reaction mixture at a temperature of 220 to 250 ° C, preferably 230 ° C, with 0.5 to 0.8 mol, preferably 0.7 mol of orthophosphoric acid, preferably at least 75 moles per mole of calcium oxide. %, react The mixture is then cooled to 120 to 140 ° C, preferably 120 to 125 ° C and centrifugation at this temperature removes inactivated calcium oxide and a portion of the free glycerol, followed by molecular distillation of the product, followed by free glycerol obtained by centrifugation ε / or the free glycerol removed by molecular distillation and / or the fatty moiety containing free aliphatic monocarboxylic acids, removed by molecular distillation and / or the distillation residue from one or more of the preceding batches returns the following batches to the starting reaction mixture. 2. The process for producing monoacylglycerols according to claim 1, characterized in that the returned glycerol constitutes up to 70% by weight of the total glycerol content of the reaction mixture and the returned fat fraction removed by molecular distillation and / or wherein said returning of said portions is carried out at least six times in a row.