Method for producing biomass granules with improved flowability

Abstract

The present invention relates to a method for producing biomass with improved fluidity, and the biomass produced by the method for producing biomass with improved fluidity of the present invention uses a solid core component in the spraying and coating process, and as compared to using the same dried biomass without the core component, the bulk density is increased, and a free-flowing desiccant product can be secured.

Description

[Technical field]

[0001] [Cross-reference to related applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0190175 filed on December 28, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a method for producing biomass granules with improved flowability, which comprises spraying and coating a specific core component with a biomass fermentation liquid or concentrate. [Background technology]

[0003] Microalgae are one of the longest-living organisms on Earth, and they not only produce biomass but also capture carbon dioxide from the atmosphere. In general, biomass is a general term for plants that use solar energy to synthesize organic matter, and the animals, microorganisms, and other living organisms that feed on them. The purpose of drying biomass derived from microalgae is to obtain a high yield when converted into high-value-added substances such as biodiesel and omega-3.

[0004] In relation to this, Korean Patent Publication No. 10-2012-0055918 discloses a method for producing bio-oil from fibrous biomass using Thraustochytrid microalgae, Korean Patent Publication No. 10-2012-0125194 discloses a method for producing biomass by culturing microalgae in wastewater from the beer industry, and Korean Patent Registration No. 10-1298942 discloses a method for producing biomass using microalgae.

[0005] Usually, the process of producing dry biomass is roughly divided into the process of harvesting the cultivated microalgae and the process of dehydrating and drying the harvested microalgae. In order to produce dry biomass, the cultivated microalgae must first be harvested. There are membrane filtration, coagulation, and centrifugation techniques for harvesting microalgae, and of these, membrane filtration is the most widely used technique as it has the highest potential for mass production.

[0006] Meanwhile, common drying methods for removing moisture from harvested microalgae include the use of drum dryers and spray dryers. Biomass is a fermentation liquid that contains oxidation-sensitive components, which often contain lipids, especially polyunsaturated fatty acids. Due to the high lipid content, when drying through commonly used drum dryers or spray dryers, the particle size and bulk density are poor and the fluidity is low, limiting its practical use as a product.

[0007] Therefore, the present inventors have endeavored to develop a method for improving the physical properties of biomass. As a result, when a specific core component is added to a fluidized bed granulator and a biomass fermentation liquid is sprayed and coated at the bottom of the fluidized bed granulator to produce biomass granules, the bulk density increases and free-flowing is possible compared to when no core component is added or the same dried biomass is added, and thus the present invention has been completed. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Application No. 10-2021-0190175 [Patent Document 2] Korean Patent Publication No. 10-2012-0055918 [Patent Document 3] Korean Patent Publication No. 10-2012-0125194 [Patent Document 4] Korean Patent No. 10-1298942 Summary of the Invention [Problem to be solved by the invention]

[0009] The purpose of this application is to 1) producing a biomass fermentation liquid or a concentrated liquid; 2) spraying and coating the fermentation liquid or concentrated liquid of 1) onto a core material to form a biomass granule.

[0010] Another object of the present application is to provide a biomass granule with improved flowability, comprising a core material, which is an amino acid or a plant-derived protein, and a biomass fermentation liquid or concentrate, wherein the core material is coated with the biomass fermentation liquid or concentrate. [Means for solving the problem]

[0011] The present invention relates to 1) producing a biomass fermentation liquid or a concentrated liquid; 2) spraying and coating the fermentation liquid or concentrate of 1) onto a core material to form a biomass granule.

[0012] The biomass fermentation liquid or concentrated liquid of step 1) can be obtained by culturing microalgae of the genus Schizochytrium or Thraustochytrium.

[0013] The biomass fermentation liquid or concentrate can contain microalgae of the genus Schizochytrium or Thraustochytrium.

[0014] The term "genus Schizochytrium" used herein is one of the genus names belonging to the Thraustochytriaceae family of the order Thraustochytriales, and may be used in the same sense as the term "genus Schizochytrium". The term "genus Thraustochytrium" is one of the genus names belonging to the Thraustochytriaceae family of the order Thraustochytriales, and may be used in the same sense as the term "genus Thraustochytrium". The term "microalgae" refers to organisms that can be seen only under a microscope and cannot be seen with the naked eye, among plants that perform photosynthesis using chlorophyll, and that live freely floating in water, and are also called phytoplankton.

[0015] The core substance in step 2) may be a protein, an amino acid or a plant-derived protein.

[0016] In the core substance, the amino acid may be any one or more selected from the group consisting of lysine (Lys), methionine (Met), tryptophan (Trp), histidine (His) and arginine (Arg), but is not limited thereto.

[0017] In the core material, the plant-derived protein may be, but is not limited to, Soy Protein Concentrate (SPC) or Soy Bean Molasses (SBM).

[0018] Step 2) is carried out using a fluidized bed granulator. The biomass solids and core materials to be made into granules are fluidized inside the fluidized bed granulator, and the biomass fermentation liquid or concentrated liquid to coat the biomass solids and core materials is sprayed from the bottom of the fluidized bed granulator.

[0019] Step 2) is carried out by a bottom spray coating method or a top spray coating method, and is preferably carried out by a bottom spray coating method. The bottom spray coating method has an advantage that it is possible to granulate / spray and coat even if the amount of the core material is small compared to the top spray coating method.

[0020] The present invention also provides a biomass granule with improved flowability, comprising a core material of an amino acid or a plant-derived protein, and a biomass fermentation liquid or concentrate, the core material being coated with the biomass fermentation liquid or concentrate.

[0021] The biomass fermentation liquor or concentrate can contain microalgae of the genus Schizochytrium or Thraustochytrium.

[0022] The "biomass fermentation liquid or concentrated liquid" can form a coating layer that coats the core material, and in this specification, the "biomass fermentation liquid or concentrated liquid" can be used in a similar sense to the term "coating liquid."

[0023] The coating may be performed by a bottom spray coating method.

[0024] The biomass granule may contain 5% or more by weight of the core material based on the total weight of the biomass granule, and may contain 5 to 30% by weight, 5 to 25% by weight, 10 to 30% by weight, 10 to 25% by weight, 15 to 30% by weight, or 15 to 25% by weight.

[0025] In the core substance, the amino acid may be any one or more selected from the group consisting of lysine (Lys), methionine (Met), tryptophan (Trp), histidine (His) and arginine (Arg), but is not limited thereto.

[0026] In the core material, the plant-derived protein is, but is not limited to, Soy Protein Concentrate (SPC) or Soy Bean Molasses (SBM).

[0027] The biomass granule may contain amino acids or plant-derived proteins as a core substance, and the protein content may be 15% by weight or more, 10% by weight or more, or 5% by weight or more based on the total biomass granule weight.

[0028] Biomass granules are 1) producing a biomass fermentation liquid or concentrate; and 2) spraying the fermentation liquid or concentrated liquid of 1) onto a core material to coat it, thereby forming a biomass granule.

[0029] The biomass granules may have an angle of repose (°) of 33° or less, 31° or less, or 30° or less.

[0030] The angle of repose is one method for evaluating the fluidity of granules, and refers to the angle of a triangular heap of granules formed by pouring a certain amount of granules, measured using a repose angle meter. The angle can be calculated by measuring the base and height of the triangle and calculating tan θ. The smaller the angle of repose, the better the fluidity can be evaluated.

[0031] The biomass granules may have a Carr's index value of 15% or less, or 14% or less, or 13% or less.

[0032] Carr's index is one of the methods for evaluating the fluidity of granules, and can be calculated by substituting the measured packing density and natural density of the granules into the following calculation formula.

[0033] [Calculation formula] Carr's Index=(Filling density - Natural density) / Filling density x 100 The smaller the Carr's index value, the better the fluidity.

[0034] Biomass granules contain amino acids or plant-derived proteins as core materials, resulting in a high protein content. In addition, they have a low angle of repose, a low Carr's index value, and improved fluidity, making them more usable than biomass powders produced using conventional methods. Effect of the Invention

[0035] The biomass produced by the method for producing biomass with improved fluidity of the present invention uses a solid core component during the spraying and coating process, so that the bulk density is increased and a free-flowing desiccant product can be secured compared to the case where the same dried biomass product is used without the core component. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The present invention will be described in more detail with reference to the following examples. However, these examples are merely for illustrative purposes and are not intended to limit the scope of the present invention.

[0037] <Preparation of microalgae fermentation liquid> To produce biomass powder, the Schizochytrium fermentation broth was collected from the fermenter. Specifically, Schizochytrium sp. strain was cultured in a 5L fermenter for 60 hours by supplying 35% glucose carbon source to the total culture broth. For the purpose of seed culture, sterilized MJW02 medium was used in a 500mL flask and cultured at 30℃ and 150 rpm for about 20 hours. The flask in which seed culture was performed was dispensed and inoculated into a 5L fermenter, and cultured in sterilized MJW02 medium and in a culture environment at 30℃, 500 rpm, 1.5 vvm, and pH 5-8.

[0038] Example 1. Preparation of biomass granules by type of core material Example 1-1. Preparation of biomass granules containing lysine as a core material After the fermentation, the biomass fermentation liquid was dried to produce biomass granules containing lysine as a core substance.

[0039] Specifically, a fluidized bed granulator (Daesung Machinery, PD-40) was used to feed biomass solids (g) and 50g of lysine as a core material, and the inlet air temperature was set at 100-130°C, the dryer internal temperature at 60-80°C, and 1400-1600g of biomass fermentation liquid was spray-dried for about 2 hours using the bottom spray coating method to form fluidized bed granules. The core material was produced at a level of 20% of the sample after final drying was completed. The amount of fermentation liquid fed in (g) and the amount of core material in the final sample (%) are shown in Table 1. In Table 1, biomass solids (g) are calculated by the solid content contained in the biomass fermentation liquid.

[0040] Example 1-2. Preparation of biomass granules containing methionine as a core material Biomass granules containing methionine as a core material were produced in the same manner as in Example 1-1 by applying the contents listed in Table 1.

[0041] Example 1-3. Preparation of biomass granules containing tryptophan as a core material Biomass granules containing tryptophan as a core material were produced in the same manner as in Example 1-1 by applying the contents listed in Table 1.

[0042] Examples 1-4. Preparation of biomass granules containing histidine as a core material Biomass granules containing histidine as a core material were produced in the same manner as in Example 1-1 by applying the contents listed in Table 1.

[0043] Examples 1-5. Preparation of biomass granules containing arginine as a core material Biomass granules containing arginine as a core material were produced in the same manner as in Example 1-1 by applying the contents listed in Table 1.

[0044] [Table 1]

[0045] Examples 1-6. Preparation of biomass granules containing soy protein concentrate as a core material After the fermentation, the biomass fermentation liquid was dried to produce biomass granules containing concentrated soy protein as a core material.

[0046] Specifically, using a fluidized bed granulator (Daesung Machinery), 50g of concentrated soy protein as the core material was spray-dried with 1485g of biomass fermentation liquid by bottom spray coating at a temperature of 60~80℃ to form fluidized bed granules. The core material was produced at a level of 20% of the sample after final drying. The amount of fermentation liquid added (g) and the amount of core material in the final sample (%) are shown in Table 2 below.

[0047] Examples 1-7. Preparation of biomass granules containing soybean molasses as a core material Biomass granules containing soybean meal as a core material were produced in the same manner as in Examples 1-6, applying the contents listed in Table 2.

[0048] [Table 2] Comparative Example 1. Production of biomass granules not containing a core material Using a fluidized bed granulator (Daesung Machinery), 1520g of biomass fermentation liquid was spray-dried without core material onto 190g of biomass solids using bottom spray coating at 60~80℃ to form fluidized bed granules. The biomass solids content (g) and the sprayed biomass fermentation liquid content are shown in Table 3 below.

[0049] Comparative Example 2. Preparation of biomass granules containing biomass powder as the core material Biomass granules containing biomass powder as a core material were prepared in the same manner as in Example 1-1, applying the contents listed in Table 3. The biomass powder was prepared by drying using a spray dryer (Ein System) at an inlet temperature of 150°C and an internal temperature of 80°C.

[0050] [Table 3] Experimental Example 1. Characterization of biomass granules according to the type of core material Experimental Example 1-1. Moisture content, angle of repose and fluidity analysis of biomass granules according to type of core material In order to evaluate the fluidity of biomass granules depending on the type of core material, the moisture content, angle of repose, and fluidity of each biomass granule produced in Examples 1-1 to 1-7, Comparative Examples 1 and 2 were analyzed as follows.

[0051] Specifically, the moisture content was measured by the loss on drying method according to the general moisture content test method of the Food Code. 3-5 g of the sample was accurately weighed, placed in a drying oven at 105°C for more than 3 hours, dried in a desiccator at room temperature for more than 30 minutes, and then weighed. The sample was then dried again in a drying oven for 1-2 hours, cooled, weighed, and repeatedly measured until the moisture content was reached.

[0052] The angle of repose was measured using a repose angle meter by pouring a certain amount of granules and measuring the angle of the triangular pile of granules. The angle can be calculated by measuring the base and height of the triangle and finding tan θ. The fluidity was evaluated using the repose angle value according to Table 4 below. The evaluation results of the moisture content, angle of repose and fluidity of the measured biomass granules are shown in Table 5 below.

[0053] [Table 4]

[0054] [Table 5] As a result, as shown in Table 5, it was confirmed that biomass granules containing the amino acids lysine, methionine, tryptophan, histidine, and arginine as core substances and biomass granules containing plant-derived proteins such as concentrated soy protein and soybean meal have lower moisture content, smaller angles of repose, and better fluidity than biomass granules not containing a core substance or biomass granules containing biomass powder as a core substance.

[0055] Experimental Example 1-2. Analysis of natural density, packing density, Carr's Index and fluidity of biomass granules according to type of core material In order to evaluate the fluidity of biomass granules depending on the type of core material, the natural density, packing density, Carr's index, and flowability of each biomass granule prepared in Examples 1-1 to 1-7, Comparative Example 1, and Comparative Example 2 were analyzed as follows.

[0056] Specifically, the natural density was measured as follows. After measuring the mass of an empty container, the container was fully filled with samples up to the top, and the samples stacked on top of the container were cut into flat plates and the mass was measured. After measuring the mass, this was repeated five or more times until the difference in the measured values ​​was within 0.3%. The measured value was substituted into the following formula to calculate the natural density.

[0057] [Calculation formula] Natural density = (weight of powder filled into empty container (g) - weight of empty container (g)) / volume of container (100 cm 2 )

[0058] The packing density was measured in the following manner. After measuring the mass of the empty container, an auxiliary cylinder was connected on top and the sample was fully packed up to the top of the auxiliary container. Then, tapping was performed more than 1000 times until there was no change in volume, and after removing the auxiliary container, the sample was cut into a flat plate and the mass was measured. This was repeated five times or more until the difference in the measured values ​​was within 0.3%. The measured values ​​were substituted into the following formula to calculate the packing density.

[0059] [Calculation formula] Packing density = (weight of cylinder completely filled with powder after tapping (g) - weight of cylinder (g)) / volume of cylinder (100 cm 2 )

[0060] Carr's index is often used as an indirect index of fluidity and is calculated by substituting the measured packing density and natural density into the following formula. The smaller this value is, the better the fluidity is.

[0061] [Calculation formula] Carr's Index=(Filling density - Natural density) / Filling density x 100

[0062] The flowability was evaluated using the Carr's index value according to the following Table 6. The evaluation results of the natural density, packing density, Carr's index and flowability of the measured biomass granules are shown in Table 7 below.

[0063] [Table 6]

[0064] [Table 7] As a result, as shown in Table 7, biomass granules containing the amino acids lysine, methionine, tryptophan, histidine, and arginine as core substances and biomass granules containing plant-derived proteins such as concentrated soy protein and soybean meal had higher natural density and significantly lower Carr's index values ​​than biomass granules not containing a core substance or biomass granules containing biomass powder as a core substance, demonstrating good fluidity.

[0065] Example 2. Production of biomass granules with different contents of core substances (lysine and concentrated soy protein) Example 2-1. Production of biomass granules containing 7.4% lysine as a core material in the final sample In order to evaluate the difference in fluidity depending on the content of the core material, the contents listed in Table 8 were applied in the same manner as in Example 1-1 to produce biomass granules containing 7.4% lysine as the core material in the final sample.

[0066] Example 2-2. Preparation of biomass granules containing 9.1% lysine as the core material in the final sample In order to evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 9.1% lysine as the core material in the final sample were produced by applying the contents listed in Table 8 in the same manner as in Example 1-1.

[0067] Example 2-3. Preparation of biomass granules containing 11.5% lysine as the core material in the final sample In order to evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 11.5% lysine as the core material in the final sample were produced by applying the contents listed in Table 8 in the same manner as in Example 1-1.

[0068] Example 2-4. Preparation of biomass granules containing 16.4% lysine as the core material in the final sample In order to evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 16.4% lysine as the core material in the final sample were produced by applying the contents listed in Table 8 in the same manner as in Example 1-1.

[0069] Example 2-5. Preparation of biomass granules containing 28.7% lysine as the core material in the final sample In order to evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 28.7% lysine as the core material in the final sample were produced by applying the contents listed in Table 8 in the same manner as in Example 1-1.

[0070] [Table 8] Example 2-6. Production of biomass granules containing 7.3% soy protein concentrate (SPC) as the core material in the final sample To evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 7.3% soy protein concentrate (SPC) as the core material in the final sample were produced using the same method as in Example 1-1, applying the contents listed in Table 9.

[0071] Example 2-7. Production of biomass granules containing 9.0% soy protein concentrate (SPC) as the core material in the final sample To evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 9.0% soy protein concentrate (SPC) as the core material in the final sample were produced using the same method as in Example 1-1, applying the contents listed in Table 9.

[0072] Example 2-8. Production of biomass granules containing 12.0% soy protein concentrate (SPC) as the core material in the final sample To evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 12.0% soy protein concentrate (SPC) as the core material in the final sample were produced using the same method as in Example 1-1, applying the contents listed in Table 9.

[0073] Example 2-9. Production of biomass granules containing 16.7% soy protein concentrate (SPC) as the core material in the final sample To evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 16.7% soy protein concentrate (SPC) as the core material in the final sample were produced using the same method as in Example 1-1 and the contents listed in Table 9.

[0074] Example 2-10. Production of biomass granules containing 27.8% soy protein concentrate (SPC) as the core material in the final sample To evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 27.8% soy protein concentrate (SPC) as the core material in the final sample were produced using the same method as in Example 1-1, applying the contents listed in Table 9.

[0075] [Table 9] Experimental Example 2. Evaluation of the fluidity of biomass granules depending on the content of core material Experimental Example 2-1. Analysis of moisture content, angle of repose and fluidity of biomass granules depending on the content of core material In order to evaluate the fluidity of biomass granules depending on the content of core material, the moisture content, angle of repose, and fluidity of each biomass granule produced in Examples 2-1 to 2-10 were analyzed in the same manner as in Experimental Example 1-1, and the results are shown in Tables 10 and 11 below.

[0076] [Table 10]

[0077] [Table 11] As a result, it was confirmed that the granule size increased as the amount of sprayed biomass fermentation liquid increased and the amount of core material in the final sample decreased, but the angle of repose value did not change significantly and the moisture content decreased.

[0078] Experimental Example 2-2. Analysis of natural density, packing density, Carr's Index and fluidity of biomass granules depending on the content of core material In order to evaluate the fluidity of biomass granules depending on the content of core material, the natural density, packing density, Carr's index and flowability of each biomass granule produced in Examples 2-1 to 2-10 were analyzed in the same manner as in Experimental Example 1-2, and the results are shown in Tables 12 and 13 below.

[0079] [Table 12]

[0080] [Table 13] As a result, it was confirmed that the more the amount of sprayed biomass fermentation liquid was increased, i.e., the lower the content of core material in the final sample, the lower the Carr's index value was, and the more fluidity was increased.

Claims

1. 1) Producing a biomass fermentation liquid or concentrate; and 2) spraying the fermentation liquid or concentrated liquid of 1) onto a core material to coat it to form a biomass granule.

2. The method for producing biomass granules according to claim 1 , wherein the biomass fermentation liquid or concentrated liquid in step 1) contains microalgae of the genus Schizochytrium or Thraustochytrium.

3. The method for producing biomass granules according to claim 1 , wherein the core substance in step 2) is an amino acid or a plant-derived protein.

4. The method for producing biomass granules according to claim 3, wherein the amino acid is one or more selected from the group consisting of lysine, methionine, tryptophan, histidine and arginine.

5. The method for producing biomass granules according to claim 3 , wherein the plant-derived protein is concentrated soy protein or soybean meal.

6. The method for producing biomass granules according to claim 1 , wherein step 2) is carried out using a fluidized bed granulator.

7. The method for producing biomass granules according to claim 1 , wherein step 2) is performed by a bottom spray coating method.

8. The method for producing biomass granules according to claim 1, wherein the biomass granules contain 5 to 30% by weight of a core material based on the total weight of the biomass granules.

9. The method for producing biomass granules according to claim 8 , wherein the biomass granules contain a core material and have a protein content of 15% by weight or more based on the total biomass granule weight.

10. The method for producing biomass granules according to claim 1 , wherein the biomass granules have a fluidity improved to a Carr's index of 15 or less.

11. A biomass granule having improved flowability, comprising a core material of an amino acid or a plant-derived protein, and a biomass fermentation liquid or concentrate, the core material being coated with the biomass fermentation liquid or concentrate.

12. The biomass granule according to claim 11, wherein the biomass granule contains 5 to 30% by weight of the core material based on the total weight of the biomass granule.

13. The biomass granule according to claim 11 , wherein the biomass fermentation liquid or concentrated liquid contains microalgae of the genus Schizochytrium or Thraustochytrium.

14. The biomass granule of claim 11, wherein the amino acid is one or more selected from the group consisting of lysine, methionine, tryptophan, histidine and arginine.

15. The biomass granule of claim 11 , wherein the plant-derived protein is soy protein concentrate or soybean meal.

16. The biomass granule of claim 11, wherein the biomass granule contains a core material and has a protein content of 15% by weight or more based on the total biomass granule weight.

17. The biomass granule according to claim 11, wherein the flowability of the biomass granule is improved to Carr's index of 15 or less.

18. The biomass granules according to any one of claims 11 to 17, wherein the biomass granules are produced by the production method of claim 1.

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