SU523935A1 - Method for neutralizing hydrolyzed vegetable raw materials - Google Patents

Description

freed from sediment, and the creeping mixture is finally neutralized with ammonia water.

Example. The hydrolysis obtained by gadrolysis wood raw material diluted sulfuric acid, is subjected to neutralization in two stages.

For this, preferably 70-75% of the hydrolyzate is separated from the total flow and neutralized with lime milk to a pH3 value, 5, corresponding to the complete binding of the sulfuric acid hydrolyzate to gypsum. After separating the precipitated gypsum by filtration to the filtrate, the content of dissolved gypsum in which is higher than its ultimate solubility (for example, 2.36 g / l versus 1.8 g / l), the rest (20-25%) of the hydrolyzate is added and the mixture is neutralized to pH 4.5 25% ammonia water. The content of dissolved gypsum in the neutralized hydrolyzate does not exceed the limiting solubility (for example, 1.76 g / l versus 1.8 g / l). The nitrogen content in it is also less than the maximum permissible (for example, 0.66 g / l versus 0.7 g / l).

To reduce the content of organic impurities in the neutralized hydrolyzate, which pollute it, the method of neutralizing wood hydrolysates can be carried out in the following embodiment.

70-75% of the hydrolyzate is separated from the total flow by neutralizing it with lime milk to a pH of 3.5 and filtering the precipitated gypsum. The content of dissolved gypsum in the filtrate, for example, 2.18 g / l.

In parallel, 20–25% of the hydrolyzate is neutralized with ammonia water to a pH of 4.5 and the organic compounds are filtered to coagulate. Hydro-isat treated with lime milk is shifted with the hydrolyzate treated with ammonia water, and the mixture is neutralized with ammonia water to pH 4.4. The content of dissolved gypsum in the neutralized hydrolyzate, for example, 1.8 g / l, and nitrogen -0.55 g / l.

It is also possible the implementation of the method in the following embodiment. Deep neutralization with ammonia water is subjected to the main stream (70-75%) of the hydrolyzate after treatment with lime milk and separation of the precipitated gypsum. In this case, the remainder of the hydrolyzate is not neutralized with ammonia water prior to mixing with the main stream.

The method is simple to implement, does not require additional reagents, and reduces lime consumption for neutralization.

In order to most deeply reduce the content of dissolved gypsum and organic impurities in the final stream, phosphates (for example, superphosphates) are introduced into the initial hydrolyzate before neutralization. Thus, technical superphosphate is introduced at a rate of 2 g / l in hot (at 90 ° C) hydrolyzate at a five-minute stirring, while the superphosphate dissolves completely, the amount of phosphate in the hydrolyzate is 0.57 g / l per anhydride. Next, the hydrolyzate is neutralized with lime milk to a pH of 3.5, the precipitated gypsum is separated and neutralized with ammonia water to pH 8, the yield of the precipitate is 1.70 g / l, including organic matter 0.74 g / l, the content of dissolved gypsum in the filtrate 1 , 49 g / l, phosphorus - 0.07 g / l; the content of dissolved gypsum in the final neutralization is 1.15 g / l.

Claims (4)

In this case, when the main stream is deeply neutralized with ammonia water after separation of precipitated gypsum from it (up to pH 6 and above), calcium as insoluble calcium monophosphate is additionally removed with organic matter and its formation contributes to a deeper coagula: organic colloids, knowing hydrolyzed. Claim 1. A method for neutralizing plant material hydrolysates, including a two-stage treatment with reagents for contacting sulfuric and organic acids, characterized in that, in order to improve the quality of neutralization and reduce the content of dissolved gypsum, eliminate equipment gypsum, in the first stage of the total flow, part of the hydrolyzate is taken for neutralization, a neutralizing agent is introduced into it, followed by separation of the precipitate from the solution and mixing the latter with the remaining part of the hydrolyzate. olisate, and in the second stage, the resulting mixture is neutralized. 2. A method according to claim 1, characterized in that, in the first stage, from the total stream directed to neutralization, a hydrolyzate is selected in an amount of preferably 70-75%. 3. A method according to claim 1, characterized in that, in the first stage, lime milk is added to neutralize the hydrolyzate, and the resulting mixture is neutralized with ammonia water. 4. Method according to paragraphs. 1-3, characterized in that phosphates, such as superphosphate, are introduced into the hydrolyzate before neutralization. 5. A method according to claim 1, characterized in that in the first stage a portion of the hydrolyzate stream in an amount of preferably 25-30% is treated with ammonia water, followed by separating the precipitated sludge, and then mixed with the main hydrolyzate stream, pretreated with lime milk and freed from sludge , and the resulting mixture is again neutralized with ammonia water. Sources of information taken into account in the examination: 1. Sharkov. V.I., Technologists of hydrolytic and sulphate-alcohol production, Goslesbumizdat, 1959, p. 148. 2. Andreev A. A., Bryzgalov L. I, Production of fodder yeast, ed. Forest industry, 1970, p.46. 3. Avt.svid. N 104439, MU C 13 K 1/02. 4. Sharkov V.I. Technologists of hydrolysis production, publishing house Lesna industry, 1973, p. 87.