DD126703B1 - Separation of aqueous cultured liquid from biomass suspensions containing hydrocarbon - Google Patents

Description

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Application of the invention:

The invention relates to a process for the separation of aqueous culture liquid from biomass suspensions obtained by cultivating microorganisms from a hydrocarbon phase. The invention relates specifically to a process in which the hydrocarbon phase is not completely consumed and is known to boil together with the adhering microorganisms Biomass / hydrocarbon / water phase forms, if you bring the KuItürgemisch in a sedimentation vessel.

The invention has been used in plants in which liquid hydrocarbons with the help of microorganisms mikrc biologically reacted and separated.

Characteristic of known technical solutions

In the cultivation of microorganisms on a carbon source in the presence of an aqueous nutrient solution of known composition, stable emulsions are formed which result from the stability of the microorganism cells localized from the phase interfaces. For the first separation of the culture fluid, it is known to use a simple float, decanter or ticris ™ Au¬ frahmuugsprczeß met. J) Only Separating Culture ™

In general, liquid contains unused nutrients which are separated from the biomass and hydrocarbon phase for further use. "In general, the culture mixture is continuously withdrawn from a fermenter and introduced into a decanter."

In this vessel, the biomass decanted almost completely together with der.Kohlenwasserstoffphase and can be removed continuously »At the bottom of the vessel, the culture liquid is withdrawn continuously.

However, the floating biomass hydrocarbon suspension still contains a high proportion of aqueous culture fluid. In the known processes, this suspension is generally separated by multi-stage separation by means of plate separators into a hydrocarbon phase, a water and a biomass-enriched water phase.

In order to keep the effort in the separation low, it is desirable to achieve even by decantation a Weil-going separation of the aqueous JCulturflüsb'igkeitsanteiles, For this purpose, various ways have already been investigated and described. In »Dl Pat ent. No. 75 .94-4- the application of a Temperatarveränderung, an electrical alternating voltage, an irradiation with electromagnetic waves, in particular short waves, infrared rays or gamma rays is described in the emulsion. DT-OS 1.54-5.252 describes a phase separation of the per-mentor effluent by separation of most of the aqueous nutrient medium by decantation and subsequent addition of at least 10 g / l of a metal salt, preferably an alkali halide and a surface-active substance in the concentration of at least 0.5 g /1.

In addition to dex · application of demulsifying substances, the exploitation of flotative effects by introducing finely dispensed air is known.

However, these methods all have the disadvantage that in industrial application additional expenses for Eilfsstoffо

or flotation facilities arise. In flotation, there is also the risk that the suspension will have an apparent showering properties owing to the finely dispersed air and is therefore technically difficult to handle,

Object of the invention:

The invention is based on the objective to design a phase separation in the context of decantation without the use of expensive tools and energy so that the subsequent separation in the separation stage without the movement of larger Produktströrae and the separation operation zu.den separators can be done with consistent quality.

Dari'jung the essence of the invention;

From the object of the invention, the technical task is the specific design of decantation to facilitate the phase separation of biomass from the other phases »

Characteristics of the E

Surprisingly, it has been found that, by exploiting the structural properties of the suspension, together with the effects of V / ater and hydrocarbons on almost all conventional technical apparatus materials, it is possible to achieve an intensive influence on the suspension, which exploits them in a targeted manner, considerably improving the separation of aqueous Kuiburflübsigkeit from the above The result of the suspension is »These suspensions consist microscopically of a nearly continuous Ya'asserpbaoe in which hydrocarbon droplets of different sizes and also air bubbles are finely distributed.

The LIikrs Organisms, s. For example, yeast cells adhere predominantly to hydrocarbon droplets. Häuf Frequently observable Д) скенорок скорания bails from the DK drops and hicco

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organismenzelien. In addition, again Viassereinschlüsse can be seen. The microstructure of the suspensions is therefore very inhomogeneous, especially in the density ratios. Due to their high hydrocarbon content, the curls have a lower density than the water phase surrounding them.

If, for example, a culture mixture comprises

Candida Guilliermondii on 20% petroleum distillate Siedelage 220 - 380 ⁰ C and aqueous Kuiturflüssigkeit in a filled with saddles beaker introduces the mixture within about 5 min in about 50% by volume of water phase and about 50% by volume biomass suspension on. After another 10 minutes, the volume ratios did not change, d. no further substantial water separation was achieved. However, shallow, slowly increasing water inclusions can be observed within the suspension, but they do not break down the suspension. If water is now slowly added to the vessel through a test soil on the bottom, so that the biomass suspension moves upwards, it can be observed that the flat water inclusions slowly assume spherical shape when the body surfaces or the container wall are in contact with each other, and sink downwards , If the same experiment is repeated without a caliper body, it can be clearly seen that most of the shallow water inclusions are carried upwards by the suspension. "In the systematic work that has been carried out, it has been found that the degree of separation of culture fluid is decisively influenced by the choice of Ratio of wall surface to Volursen the decanter and can be influenced by the volume flow of the suspension.

The highest degrees of separation were achieved when additional conical surfaces in the form of sheets, sieves, calipers, Raschi 'rings or turnings were created in the vessel *

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The precursors that take place at the interface are obviously of a complex nature, whereby the hydrocarbons or microbial metabolites adsorbed in monomolecular films certainly also play a role. However, they express themselves overall in an increase in the separation of the culture liquid up to two times under otherwise identical conditions as in the following Beispie3.en still be shown.

Ks were observed in addition to the increase in the degree of separation and the fact that the proportion of large hydrocarbon droplets in the suspension has significantly increased after passing éіпея decanter with additional contact surfaces, which certainly also affects the'Wasserabtrennung from the suspension.

In general, the investigations were carried out with the suspension flow velocities characteristic of these processes in a decanter of about 0.2 to 10 cm / minute. Higher flow rates affect the process in principle negative because then the Pallgeschwindigkeit of the droplets can be exceeded in the suspension.

Low speeds have the consequence that the vessels must be disproportionately large. Abor au recognize that at these low flow rates disturbing the internal structure of the creamy suspension hardly occurs.

On the other hand, if one tries to create a disturbance by stirring, then no effective effect will be obtained, 6a stirring the water agglomerates again will be divided.

Au gfuhru ng sbc mp le s

In the following table, exemplary embodiments are given for the continuous operation of a 1.1 m ¹ decantata ion cell with different internals. In order to clarify the effect of the solution according to the invention, column 1 of the table shows a control without any built-in components.

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led, and therefore, apart from the modification of the internals, the same technological parameters were used «

The decantation cells represent a cubic G. vessel with 1 m edge length, in the bottom of which a pyramidal tip terminates. At the bottom, the separated culture liquid is withdrawn. At a height of approx. 0.3 m above the ground edge, the product feed is drilled into the holes via three distributor rings. The surface of the vessel was swept over by a "clearing device" driven by tracks, through which the dehydrated suspension was transported to a receiver »

These de / kantationssellen v / ground continuously with a culture mixture consisting of about 20% petroleum distillate Siedelage 220 - 360 ⁰ C, 8.1% yeast cells (= about 2.0 % yeast dry matter) and about 82 % mechanically separated aqueous culture liquid (Water) fed from a continuous fermentation plant. The quantity supplied was around 2 t / h »The duration of a trial lasted around 120 h. During the experiment, the separating layer was regulated in a constant manner in the chute of the vessel, for example. Every 2 hours », the dehydrated suspension of yeast dry matter content was analyzed to determine the degree of separation.

The following examples were investigated: Example 1: Control experiment without fixtures Example 2i Ia distance of 0.1 m hinged sheets

Example 3: on a false bottom in 0,4 -ra. Cows until the

10 cm diameter ceramic distillation saddle body

Example 4: Teflon coated on the same bed

(Polytetrafluoroethylene) - ^ rohspäne (0.5 mm chip thickness, turned from eignem 5 ^ m diameter Teflonstabmate.rial strong ".

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The following results were achieved:

1 2 3 4 HTS concentrate % 3.01 3.52 4.02 5.51 Water separation % 41.6 53.0 61.0 77.5

% HTS in the separated culture fluid 0.016 0.015 0.015 0.014

From this table it can be seen that the degree of water separation increases with the increase of the contact surface. «

Claims (3)

Invention claim? 1. separation of aqueous Kulturflüsnigkeit from hydrocarbon biomass suspensions by decantation, characterized in that the decantation on Fontaktflächen in Eorm of sheets, sieves, saddles, Raschig rings or turnings with a surface load ο ρ below 10 cnr of suspension per cm of contact area and hour at a flow rate of the suspension of 0.5 - 10 cn per Hinute, 2. Separation of aqueous culture fluid according to Unict 1, characterized in that the suspension contains 5 to 50 % of hydrocarbons. « 3. Separation of aqueous culture fluid according to item 1 and 2, characterized in that the Siedelage the Kohlomvai is. Hydrocarbons under normal conditions 100 - A-OO ⁰ C