DD160231A3 - PROCESS FOR OBTAINING AND DISTRIBUTING BIOMASS - Google Patents

Abstract

The invention relates to a process for the recovery and separation of biomass obtained by microbial conversion of hydrocarbons, for example petroleum distillates and yeasts, as a production stagnant and can be used in the microbiological industry. The aim of the invention is to make the process for the extraction and separation of biomass grown on hydrocarbons so that the technological cost can be reduced, the biomass shows a favorable extraction behavior and high quality requirements. The object of the invention is to provide a method in which a biomass is obtained whose micro- and macrostructure allows a maximum degree of extractive purification of existing hydrocarbon radicals and biogenic ingredients. According to the invention, the extraction and separation of biomass is carried out in two stages by separating the microorganisms / hydrocarbon phase from the aqueous culture medium by decantation and subsequently separating off the remaining residual hydrocarbons and the process water by heating in a separative way. The resulting process water is returned to the fermentation process.

Description

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title

Process for the extraction and separation of biomass

A field of application of the invention

The invention relates to a process for the recovery and separation of biomass, which was grown by a microbial conversion of hydrocarbons, particularly petroleum distillates with a chain length range Cq to C _50, with yeasts.

It can be used in the microbiological industry and is classified in the IPK C 12 N.

Characteristic of the known technical solutions

Microbial biomasses obtained by cultivating hydrocarbons based on hydrocarbons, for example petroleum distillates or alkanes of the chain length range Cq to C ~ q, are subjected to various process steps after the cultivation process, which are intended for their recovery and separation. The fermentation medium consisting of four phases - biomass / aqueous culture medium / petroleum distillate / air - must be separated and the biomass obtained must be purified in a subsequent extraction process. · The biomass is extracted and separated by mechanical and / or thermal separation processes.

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Methods are known which include processes of creaming or decantation, separation, vacuum evaporation and drying (WP 139 949, WP IO4 099). In addition, concentration processes are also known in which predominantly 5 mechanical separation processes are used. Thus, the use of high-performance separators enables a biomass enrichment of up to about 20 to 22%, so that a vacuum evaporation stage subsequent to the separation can be dispensed with.

Crucial to the extractability of the biomass to remove residual hydrocarbons is their micro- and macrostructure. An encapsulation of the substance to be extracted in the biomass leads to reduced extractability and thus to increased technological effort for the extraction. Therefore, in the known methods for obtaining and separating biomass from hydrocarbons, the idea of obtaining a biomass dry substance whose physicochemical property enables optimum extraction behavior in the removal of undesirable biogenic and nonbiogenic substances plays a major role. This requirement meet the known methods only imperfectly. The dry grain obtained after the drying process, mainly spray-drying process, is encapsulated in its microstructure and macrostructure, exhibits unfavorable mass transfer coefficients, low capillary activity and reduced porosity for the extractive purification diffusion processes. As a result, the extractive purification operations require a great deal of equipment and technology To obtain a biomass of the required quality »This increased effort can mechanical pretreatment of the dry product, its mashing or · pre-swelling with water or« selective solvents or the use of special extractors and extractant mixtures includes WP 139 650, WP 139 651, WP 142 488, WP 142 489).

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The described disadvantages resulting from the undesirable structure of the biomass also relate to the technology for removing the extractants from the purified biomass, where they cause a similar additional expense ·

Object of the invention

The aim of the invention is to make the process for the extraction and separation of biomass grown on hydrocarbons so that the technological and equipment cost can be reduced, that the biomass obtained is well extractable to remove residual hydrocarbons and biogenic ingredients, and high Meets quality requirements.

The object of the invention is to develop a process for the extraction and separation of biomass, as a result of which a biomass is obtained whose microstructure and macrostructure permit the highest possible degree of extractive purification for the removal of existing hydrocarbon radicals and biogenic constituents.

Explanation of the essence of the invention

According to the invention, the object is achieved in that the process for the recovery and separation of biomass obtained by microbial conversion of hydrocarbons with yeast is designed so that the separation of the aqueous culture medium from the four-phase biomass / culture medium / residual hydrocarbon / air carried out in two stages becomes. In a first stage, referred to as creaming, the normal conditions are separated from the aqueous culture medium by decantation of the microorganisms / hydrocarbon phase. The achieved degree of dewatering is between 40 and 70 vol. SS, preferably 55 to 65 vol .-% · Subsequently, the aqueous biomass suspension to 60 90 ⁰ C, but preferably 80-85 ° C, heated, the remaining residual hydrocarbons on separativem Paths and other process water also separated in one

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separated separation stage, with degrees of concentration between 10 to 23 % biomass dry substance can be achieved. By recycling the accumulated here and the process water obtained in the above decantation in the continuous process of fermentation, a biomass is obtained in the micro and macro area with inorganic components such as potassium, iron, magnesium, zinc, manganese, from the yeast cell in the aqueous medium is discharged and the porosity of the biomass favorably influenced, saturated · is particularly favorable the return of the after the temperature increase to 60 to 90 ⁰ C separated by separation process water on the structure of the biomass

 The described inventive measures a biomass is obtained, which contains inorganic components due to the specific process conditions and thereby undergoes a structural structure that does not allow encapsulation d'es grain. The associated favorable extraction behavior makes it possible to obtain a biomass that meets the high quality requirements of a feed yeast.

embodiment

The invention will be explained in more detail with reference to the following example.

In a stirred fermentor with a capacity of 250 t and a working volume of 90 t, the yeast strain Lodderomyces elongisporus IMET H 128 is cultivated on a petroleum distillate fraction with the carbon chain length C ₁ Q to Cpg in a continuous process.

The n-alkane content in the petroleum distillate is 17.0% by mass, the stirring power in the per- mentor 210 KW, the registered air volume 6900 Dr / h.

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The composition of the culture medium, based on one cubic meter of water, is:

Phosphoric acid (74%) 590 ml

Potassium chloride 620 g

Magnesium sulfate 290 g

Ferric chloride 21 g Manganese sulfate 19 g

Zinc sulfate 16.5 g

An auxiliary of the type of a propylene oxide ethylene oxide adduct in a concentration of 600 mg / 1 process water is added to the process water to intensify the process of the fermentation. The pH is adjusted with concentrated ammonia solution and adjusted to 4.2. The per- ⁴ · mentationstemperatur is 33 ° C, the residence time 4 hours. The productivity of the fermentation process is 3.7 kg / t · h.

The permentor spout is placed in a frying vessel within 30 minutes to cream the yeast and the oil. Here it is possible to separate 60% of the process water and there is also a degassing.

For the biomass / oil suspension about 0.8 g of Hilfstoffee described again added and the suspension is heated to 85 ° C. The separation of oil is carried out by a separative route and thereafter the biomass suspension is likewise concentrated separately to 19.2% by mass of yeast dry matter. The resulting aqueous culture media, namely 40 % of the process water obtained from the creaming stage and 100% of the process water separated by a separate means, are recycled continuously to the per-mentor.

Overall, a degree of recycling of 75 % of the aqueous medium is realized.

The concentrated biomass suspension is dried using a conventional spray drying process. The yeast dry substance has the following composition. Yeast dry matter 90.7 Ma. -% crude protein content 6i, 5Ma .-% water content 6.3 Ma.-Sß

Ash content 3.0% by mass

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The yeast dry substance is extracted in a continuous, semi-rotary extractor at 4O ⁰ C with the selective extraction mixture gasoline-ethanol-water = 80-19-1% by volume. Here, a very good extraction behavior is achieved, which is characterized in that in the withdrawn Miszella a pesticide content of <0.1 % is achieved. After removal of the residual extractants present in the extractively purified biomass, an end product of high quality is obtained.

Composition of biomass:

Crude protein content 62.1 Ma. -%

Water content 5.2 Ma. -%

Ash content 2.8 Ma. -%

Hydrocarbon content 0.19Ma .-%

Aromatic content 0.0032 Ma. -%

The advantages of using the method according to the invention are in addition to the recovery of a biomass with favorable extraction behavior in reducing the fresh water requirement, the rational use of inorganic Uähr- and trace salts, as well as auxiliaries, e.g. Surfactants in the fermentation process. In addition, can be dispensed with certain process steps, such as the evaporation of the process water.

Claims (2)

230219 · 3 Invention claim 1. A process for the recovery and separation of biomass obtained by microbial conversion of hydrocarbons with yeasts, characterized in that the separation of the aqueous culture medium from the four-phase system biomass / culture medium / residual hydrocarbons / air is carried out in two stages, referred to as a creaming first dehydration stage, which is carried out under Kormalbedingungen, the pre-dewatered Biomssesuspension to 60 to 90 ⁰ C, preferably 80 to 85 ⁰ C, heated and the removal of the residual hydrocarbons are realized by a first separation and the further dewatering by a second separation, wherein the each separated process water from all stages is continuously recycled to the fermentation process, so that a maximum saturation of the biomass with the constituents of the process water, in particular the inorganic, the particularly advantageous for extraction micro and macro-structure of biomass. 2, process according to item 1, characterized in that preferably the process water obtained after heating to 60 to 90 ° C and subsequent separation or a part thereof is recycled to the fermentation process «