DD160230A3 - PROCESS FOR EXTRACTION OF DRIED MICROBIAL BIOMASSES - Google Patents

Abstract

The invention relates to a process for the removal of hydrocarbons from dried biomass by Zuecht. v. Microorganisms were obtained on hydrocarbon-containing substrates. She belongs in d. Area d. microbial protein production. It is the object of the invention to significantly reduce the content of dry biomass of hydrocarbons and reduce the effort for extraction. The object of the invention is to use additives in the mixture biomass / extractant to achieve the object of the invention. This object is achieved according to the invention in that the extraction of the dry biomass previously brought to a water content of 20 to 60% by mass with hydrocarbons in the boiling range from 40 to 140 ° C. in the presence of, based on dry biomass, 0.01 to 5 Ma. -% surfactants of the polyethylene glycol type is carried out. The addition of the surfactants can be carried out in the stages of fermentation and / or separation and / or extraction.

Description

230U0 8

Title of the invention;

Process for extracting dried microbial biomass

Field of application of the invention:

The invention belongs to the field of microbial protein production, IPK C 12 K. The invention can be used in plants in which microbial biomasses are prepared and purified by solvent extraction in which lipophilic constituents are removed from protein-rich products by solvent treatment.

Characteristic of the known technical solutions;

Microbial biomass grown on hydrocarbons as a substrate still contains substrate levels, i. Hydrocarbons that must be removed from the biomass. For this, methods are known in which a solvent extraction of the dried biomass takes place. The solvents used are hexane or lower gasoline cuts, ketones, methanol or mixtures of hexane or hexane-rich gasoline cuts with ketones (acetone), alcohols (methanol, ethanol, isopropanol) and / or water.

The use of solvent mixtures, in particular of hydrocarbons and alcohol, leads to technologically only with considerable effort manageable phase separations in internal circuits, but is preferably used because of the high purity of the resulting purified products.

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A technologically more easily controllable process is to carry out the extraction with hydrocarbons (DD-AP 53984). However, the end product grades containing are inferior because of the higher content of hydrocarbons.

Furthermore, it is known that to improve the end product qualities in the extraction (DD-PS 110 052) or to improve the Absinkverhaltens in the extraction in continuous agitator column extraction (DD-PS 139 650) when using hydrocarbons as extractant water introduced into the extraction system However, the resulting pesticides in their content of hydrocarbons do not meet the requirements, ie, their content of hydrocarbons from the carbon source used in the fermentation substrate (petroleum distillate) is still too high. Only through a variety of extraction stages can it be brought to the required low level.

Object of the invention:

The aim of the invention is to reduce by suitable means and measures the content of the extracted biomass of hydrocarbons significantly and thus to reduce the effort to improve the extraction effect. Explanation of the essence of the invention;

The invention has for its object to achieve a faster and thus more thorough removal of the lipophilic substances and thus also the hydrocarbons by an additive in the extraction of dried and subsequently with water or aqueous biomass suspensions to a water content of 20 to 60 mass # brought biomass.

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Surprisingly, it has been found that surfactants are particularly effective as additives in the extraction of moistened with water or aqueous biomass suspensions biomass with hydrocarbons in the boiling range of 40 - 14O ° C. A particularly good effectiveness nonionic surfactants of the polyethylene glycol type. Of these surfactants, both those having a low HLB number (oil or gasoline-soluble) and those having a medium or high HLB number (water-soluble) are suitable.

Thus, compounds of the general formula HO - (CH ₂ -CH ₂ -O) _n - R ₁ -R ₂

in amounts of from 0.01 to 5.00% by weight, based on the amount of pesticides, is particularly effective. Where:

R _{1 is} an alkylene or acylene radical having 6-22 C atoms or a radical (-CH-CH ₂ -O-) _ffl with

m β 3 to 250

R _{2 is} a radical (-OH-CH ₂ -CH ₂ ) _n -CH or H η is a number from 3 to 200

For example, polyethylene glycol ethers of medium to long-chain fatty alcohols or polyethylene glycol esters of medium to long-chain fatty acids and polycondensation products of ethylene oxide with polypropylene glycol, individually or in a mixture of good activity.

The addition of the surfactant or of the surfactants can be carried out in each stage of the process of producing the biomass up to and including the extraction. The stages of fermentation, creaming, separation or extraction are preferred individually or in combination. The addition of different surfactants in individual stages is also possible. Advantageously, the addition of the surfactants having a moderate or high HLB number is carried out via the aqueous system and that of the surfactants of low HLB number via the extractant.

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Because of the use of the extracted biomasses as animal feed additives, the surfactants are of the ethoxylated polypropylene glycols or ethoxylated straight chain alcohols of medium to high chain length or of the polyethylene glycol fatty acid esters of medium to long chain fatty acids as well as biogenic phospholipids or diglycerides of medium to long chain fatty acids (C _Q to C ₂₂ ) or surface-active sugar esters are particularly suitable ·

EXAMPLES

1 »example;

In a circulating extractor of 10 liters of content are added 2.5 kg of spray-dried biomass, which was obtained by culturing Lotteromyces elongisporus on a petroleum distillate boiling range 250 to 36O ⁰ C as the sole C source · Add 1.25 kg of water with stirring , so that the biomass has a water content of 40% · For 15 minutes is stirred for uniform distribution of the added water occasionally · Then 5 kg of gasoline of the boiling range 60/85 ⁰ C is added, which has a temperature of 40 ⁰ C and in which 25 g of 7-Eto-dodecanol are dissolved. While maintaining the temperature, the mixture is stirred for 15 minutes and then filtered. The separated filter cake is extracted three more times analogously with a solution of 25 g of 7-ethodecanol in 5 liters of gasoline boiling at 60 ° to 85 ^° C. at 40 ^° C. and after separation the Miszella the filter cake is air-dried. The hydrocarbon content of the extracted product was 0.14% by mass and the extract amount was 450 g. In a comparative experiment without surfactant addition, the hydrocarbon content of the extracted product was 0.58% by mass and the extract amount was 235 g.

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2 »Example:

In an extractor as in Example 1, 2.5 kg of biomass were added as in Example 1. The moistening was carried out outside the extractor with one liter of a 19% biomass suspension containing 0.3% of a surfactant. This surfactant was an ethoxylated polypropylene glycol having an average molecular weight of 1950 and a ratio of propylene oxide: ethylene oxide 53: 47 · The wet solid was extracted as described in Example 1, four times at a temperature of 4O ⁰ C with a gasoline boiling range from 60 to 85 ⁰ C. The dried pesticide had a hydrocarbon content of 0.23%, it incurred 325 g of extract. In a comparative experiment without surfactant, the extracted pesticide had a hydrocarbon content of 0.67 Ma. % and only 215 g of extract were obtained.

3 * example;

On a petroleum distillate boiling range 250 - 36O ⁰ C, a yeast strain of the species Lodderomyces elongisporus was continuously cultured in a continuous stirring fermentor of 3 30 nr content. The stirring power of the per- mentor was 20 kW with an air intake of 750 nr / h. The culture medium had, based on 1 nr liquid, the following composition: phosphoric acid (70%) 600 ml, potassium chloride 600 g, magnesium sulfate 280 g, iron (II) chloride 20 g, manganese sulfate 20 g, zinc sulfate 15 g · To improve the extraction behavior of the spray-dried product were added to the fermentor liquid according to the invention 800 g of the surfactant as in Example 2 per nr culture liquid. At the same time, the temperature kept at 33 ⁰ C and the pH by adding ammonia at 4.2 "The productivity was 3.8 kg / nr ^# h. By creaming carried out a concentration of biomass to 3.2 g / l with simultaneous degassing. The suspension was then added according to the invention again with 1 kg / nr cream of the surfactant as in Example 2

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and after heating to a temperature in the range of 80 85 ⁰ C subjected to a separation separation of the main amount of oil · In a second separation stage was concentrated to a pesticide content of 20.4%. This suspension was dried by means of a conventional spray drier with pressure nozzle atomization and had the following composition: crude protein 58.3%, water 14.3%, lipids 22.2%, hydrocarbons 8.3%, surfactant content 1.27%, particle size 0.050 to 0.500 mm After moistening to 30% water content, extraction was effected four times with η-hexane as in Example 1. The pesticide had a hydrocarbon content of 0.32%, and a sample which had been fermented and separated comparatively without surfactant still had a hydrocarbon content after extraction of 0.85%.

4 «Example;

The spray-dried biomass from Example 3 was moistened as indicated in Example 1 to 45% water content and extracted with the addition of 0.5% Laurinsäurepentaethylenglycolester to extraction gasoline. The extraction was carried out in 4 stages at 45.degree. The resulting pest had a hydrocarbon content of 0.12%.

In a comparative experiment, the extraction of the same pesticide with pure gasoline, ie without the addition of the surfactant. This extracted pesticide still contained 0.24% hydrocarbons.

Claims (6)

230U0 8 claim for invention 1 · Method for extracting dried microbial
Biomass from microorganisms bred on petroleum distillates with hydrocarbons in the boiling range of 40 to 140 ⁰ C, preferably 55 to 90 ⁰ C, with a water content of the biomass of 20 to 60%, characterized in that the extraction in the presence of 0.01 to 5.0 %, based on biomass, of one or more surfactants of the general formula
HO- (CH ₂ -CH ₂ -O) _n -R ₁ -R ₂ wherein R- is an alkylene or acylene radical having 6 to 22 carbon atoms or a radical
(-CH - CH ₂ - 0 -) _m with m = 3 to 250, R _{2 is} a radical (--0 - CH ₂ - CH ₂ -) _{n is} OH or H and η is a number from 3 to 200. 2. The method according to item 1, characterized in that the addition of the surfactant to the solvent. 3 · Method according to item 1, characterized in that the moistening and addition of surfactant is carried out before the contact of the biomass with the extraction hydrocarbons. 230U0 8 4 · Method according to item 1, characterized in that moistening and surfactant addition takes place after contact of the biomass with the extraction hydrocarbons. 5 Process according to point 3 and 4, characterized in that the addition of the surfactant to the pesticide takes place before, during or after the moistening with water and / or aqueous biomass suspension. 6. The method according to item 1, characterized in that the addition of the surfactant is carried out in the stage of fermentation and / or separation ·