RU2786987C1 - Method and apparatus for cultivating microalgae using a fugate of alcohol distiller's spent grains - Google Patents

Abstract

FIELD: biotechnology.

SUBSTANCE: invention relates to biotechnology, namely, to a method and apparatus for cultivating microalgae chlorella using a fugate of alcohol distiller's spent grains. It is proposed that the composition of the nutrient medium include the liquid phase of alcohol distiller's spent grains — fugate, produced by centrifuging the alcohol bard. After separation, the fugate is supplied to the cooling unit, then to the dosing unit and to the nutrient medium normalising unit, then the fugate is supplied to a photobioreactor with a suspension of a strain of microalgae together with a special nutrient medium, wherein cultivation thereof is conducted.

EFFECT: possibility of shortening the cultivation time of microalgae.

4 cl, 2 dwg

Description

Technical field

The invention relates to the field of biotechnology, namely to a method and device for growing microalgae.

State of the art

During the production of alcohol from grain raw materials, a significant amount of production waste is generated - post-alcohol liquid stillage, which, when discharged into drains, causes environmental pollution. At the same time, vinasse has a well-known nutritional and fodder value, since it is in the vinasse that all grain protein remains after the starchy components are processed into ethanol. In agriculture in many countries, products based on stillage, containing protein, easily digestible carbohydrates, vitamins, micro- and macroelements, are widely used.

From the application WO 2010127182, published 04.11.2010, a method for the production of biofuels and biodiesel using stillage is known, while the stillage is grain from distillers with soluble substances (WDGS), grain from distillers with soluble substances (DDGS), grain from condensed distillers with solubles (CDS) or grain from distillers (DG).

From the patent of the Russian Federation 2556122, published on 07/10/2015, a method for processing distillery stillage is known, in which a light filtrate (centrate) from a sedicanter is fed for additional processing to a photobioreactor with microalgae, where the biomass of microalgae is increased and a finished feed product is obtained in the form of a suspension of microalgae.

The disadvantages of the known method are:

- the light filtrate from the sedicanter is fed for additional processing into the photobioreactor with microalgae, it is not taken into account that the temperature of the light filtrate at the outlet of the sedicanter is 90°C, at which microalgae cells die;

- light filtrate is not a nutrient medium, it is only an addition to the nutrient medium;

- the amount of light filtrate supplied to the photobioreactor is not dosed, as a result of which the excess of the filtrate dose causes the death of the microalgae culture;

- the pH value (measure of acidity) of the light filtrate is 4.2-4.5 and after introduction into the culture of microalgae it must be adjusted to a level of at least 7.0-7.2, otherwise the growth of microalgae biomass will not occur;

- when introducing centrate obtained during the processing of wheat or other grain materials (corn, barley, etc.) and their mixtures with wheat, it is first necessary to conduct a biological test for their acceptability for use in the cultivation of microalgae.

The essence of the invention

The aim of the invention is to eliminate the above disadvantages.

The technical result achieved by the claimed invention is to reduce the cultivation time.

More specifically, the technical result achieved by the claimed invention is to reduce the time of cultivation of microalgae due to the use of centrate as an organic additive in the composition of the nutrient medium.

The technical result is achieved by the fact that, according to the invention, the method for cultivating microalgae using distillery stillage centrate includes:

- separation of vinasse into a dispersed phase and a liquid medium (fugate),

- centrate supply to the cooling unit to bring the microalgae strain suspension to the optimum temperature,

- supply of centrate to the dosing unit for its introduction in an amount that does not cause the death of microalgae,

- supply of the centrate to the block of normalization of the nutrient medium, for the introduction of the centrate into the suspension of the microalgae strain,

- feeding the suspension of the microalgae strain into the photobioreactor for cultivating microalgae and obtaining biomass.

In a preferred embodiment of the proposed method, the following strain is used as the microalgae strain: Chlorella vulgaris BIN.

In a preferred embodiment of the proposed method, planktonic strains of microalgae are used, for the cultivation of which a nutrient medium is used, of the following composition:

Nitrogen-phosphorus, solution: 0.25 ml; Ferric chloride, solution: 0.15 ml; Copper-cobalt, solution: 0.010 ml; Potassium sulphate, solution: 0.20 ml; Centrate distillery stillage: 10 ml; Tap water: 1000 ml.

In a preferred embodiment of the proposed method, the pH of the centrate, after being introduced into the culture of microalgae, is adjusted to the values: 7.0-7.2.

Another object of the claimed invention is a device for cultivating microalgae using distillery stillage centrate, including:

- a block for separating stillage into a dispersed phase and a liquid medium (fugate),

- unit for cooling the centrate to the optimum temperature of the suspension of the microalgae strain,

- dosing block of centrate in an amount that does not cause the death of microalgae,

- centrate rationing unit as a nutrient medium in the photobioreactor.

Description of drawings

The figure 1 schematically shows the method of cultivating microalgae using distillery stillage centrate.

Figure 2 schematically shows a device for cultivating microalgae using distillery stillage centrate.

Positions in figure 2:

1 - stillage separation unit, 2 - cooling unit, 3 - dosing unit, 4 - normalization unit, 5 - photobioreactor.

Implementation of the invention

The method and device for cultivating microalgae using centrate distillery stillage can be implemented as follows.

The stillage separation unit (1) into a dispersed phase and a liquid medium (centrate) can be made in the form of a decanter - a horizontal centrifuge with a screw unloading of continuous action, designed for mechanical centrifugal separation (separation) due to the difference in density of substances.

Next centrate is fed into the cooling unit (2) for its cooling to the optimum temperature of the microalgae strain suspension. The centrate cooling unit to the optimal temperature of the microalgae strain suspension can be made in the form of a device heat exchanger in which heat exchange is carried out between two media having different temperatures. The optimum growing temperature depends on the type of strain being cultivated. Strains are subdivided into thermophilic, mesophilic and cryophilic. The selection of the temperature level should be carried out by analyzing the natural habitat of the strain. The optimum temperature of the suspension, regardless of the type of illumination from the beginning of cultivation to completion should be 28-30°C.

Next centrate is fed into the dosing unit (3) for dosing it in an amount that does not cause the death of microalgae. The centrate dosing unit can be made in the form of a dispenser - a device for automatically measuring (dosing) and issuing a given mass or volume of a substance in the form of portions or a constant flow rate with a specified error. The composition of the nutrient medium included:

Nitrogen-phosphorus, solution: 0.25 ml; Ferric chloride, solution: 0.15 ml; Copper-cobalt, solution: 0.010 ml; Potassium sulphate, solution: 0.20 ml; Centrate distillery stillage: 10 ml; Tap water: 1000 ml.

Next, the centrate is fed into the rationing unit (4) of the nutrient medium, for the introduction of the centrate into the suspension of the microalgae strain. The nutrient medium is added in a ratio of 1:1 for the formation and activation of bacterial-algological microbiocenosis.

Further, the suspension of the microalgae strain together with the nutrient medium is fed into the photobioreactor (5) for the cultivation of microalgae. The following strain can be used as the microalgae strain: Chlorella vulgaris BIN.

The photobioreactor is filled with the initial suspension of microalgae to the required volume. Illumination of the culture of microalgae in the photobioreactor is carried out naturally or with lamps for 8-10 hours. Stirring of the culture of microalgae in the photobioreactor is performed every two hours of cultivation. After adding the nutrient medium, the pH of the culture is measured. If the indicator is below 7.0, it is necessary to bring the pH in the culture to 7.0-7.2. After 10 hours of cultivation, the optical density of the culture was determined, which reached the standard. The yield of dry biomass was 1.2 g/L. The cultivation period was 1 day.

Thus, as a result of using the method and device for cultivating microalgae using centrate post-alcohol stillage, the time of its cultivation is reduced.

Claims (20)

1. A method for cultivating chlorella microalgae using post-alcohol stillage centrifuge, including: - separation of vinasse into a dispersed phase and a liquid medium (fugate), - centrate supply to the cooling unit to bring the microalgae strain suspension to the optimum temperature, - supply of centrate to the dosing unit for its introduction in an amount that does not cause the death of microalgae, - supply of the centrate to the nutrient medium standardization unit for the introduction of the centrate into the suspension of the microalgae strain, - feeding the suspension of the microalgae strain into the photobioreactor for cultivating microalgae and obtaining biomass, moreover, the pH of the centrate, after being introduced into the culture of microalgae, is adjusted to values of 7.0-7.2. 2. A method for cultivating chlorella microalgae using distillery stillage centrate according to claim 1, characterized in that the following strain is used as a strain of chlorella microalgae: Chlorella vulgaris BIN. 3. A method for cultivating chlorella microalgae using post-alcohol stillage centrate according to claim 1, characterized in that the following composition is used as a nutrient medium: Nitrogen-phosphorus, solution: 0.25 ml; Ferric chloride, solution: 0.15 ml; Copper-cobalt, solution: 0.010 ml; Potassium sulphate, solution: 0.20 ml; Centrate distillery stillage: 10 ml; Tap water: 1000 ml. 4. A device for cultivating chlorella microalgae using post-alcohol stillage centrate according to the method according to claims 1-3, including: - a block for separating stillage into a dispersed phase and a liquid medium (fugate), - unit for cooling the centrate to the optimum temperature of the suspension of the microalgae strain, - dosing block of centrate in an amount that does not cause the death of microalgae, - centrate rationing unit as a nutrient medium in the photobioreactor.

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