Method for producing biomass granules with improved fluidity

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-Citation of Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0190175 dated 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 a step of 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. Generally, biomass refers to plants that use solar energy to synthesize organic matter, as well as the animals, microorganisms, and other living organisms that feed on them. The purpose of drying microalgae-derived biomass is to ensure high yields 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 cultivating microalgae in beer industry wastewater, and Korean Patent Registration No. 10-1298942 discloses a method for producing biomass using microalgae.

[0005] The process of producing dry biomass can generally be divided into two main steps: harvesting cultivated microalgae and dehydrating and drying the harvested microalgae. To produce dry biomass, the cultivated microalgae must first be harvested. Microalgae harvesting techniques include membrane filtration, flocculation, and centrifugation, with membrane filtration being the most widely used method as it has the 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 containing oxidation-sensitive components, which often contain lipids, particularly polyunsaturated fatty acids. Due to the high lipid content, drying using commonly used drum dryers or spray dryers results in poor particle size and bulk density, low fluidity, and limited practical use as a product.

[0007] Therefore, the present inventors have endeavored to develop a method for improving the physical properties of biomass, and 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 becomes possible compared to when the core component is not added or when the same dried biomass is added, and this has led to the completion of the present invention. [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 Registration 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 concentrate; 2) spraying the fermentation liquid or concentrated liquid of 1) onto a core material to coat it, thereby forming a biomass granule.

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

[0011] The present invention provides 1) producing a biomass fermentation liquid or concentrate; 2) spraying and coating the fermentation liquid or concentrated liquid 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] As used herein, the term "Schizochytrium" refers to a genus belonging to the family Thraustochytriaceae in the order Thraustochytriales, and may be used in a similar sense to the term "genus Schizochytrium." The term "Thraustochytrium" refers to a genus belonging to the family Thraustochytriaceae in the order Thraustochytriales, and may be used in a similar sense to the term "genus Thraustochytrium." The term "microalgae" refers to plants that perform photosynthesis using chlorophyll, and are visible only with a microscope, floating freely in water, and are also known as 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 performed using a fluidized bed granulator. The biomass solids and core material to be granulated are fluidized inside the fluidized bed granulator, and the biomass fermentation liquid or concentrated liquid to coat the biomass solids and core material is sprayed from the bottom of the fluidized bed granulator.

[0019] Step 2) is performed by bottom spray coating or top spray coating, preferably bottom spray coating. The bottom spray coating method has the advantage that it can be granulated / spray coated even with a smaller amount of core material than the top spray coating method.

[0020] The present invention also provides biomass granules with improved fluidity, which contain a core material of an amino acid or a plant-derived protein and a biomass fermentation liquid or concentrate, and the core material is 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 the same sense as the term "coating liquid."

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

[0024] The biomass granules may contain 5% or more by weight of the core material relative to the total weight of the biomass granules, and may also 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 granules 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 weight of the biomass granules.

[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 angle of repose (°) of the biomass granules may be 33° or less, 31° or less, or 30° or less.

[0030] The angle of repose is a method for evaluating the fluidity of granules. It is measured using a repose angle meter to measure the angle of a triangular heap of granules formed by pouring a certain amount of granules. 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, 14% or less, or 13% or less.

[0032] Carr's index is a method 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 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 the core material, 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. [Effects 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 the bulk density is increased compared to when the same dried biomass is used without the core component, thereby ensuring a desiccant product that is free-flowing. DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention will be described in more detail below through examples. However, these examples are intended to illustrate one or more specific examples, and the scope of the present invention is not limited to these examples.

[0037] <Preparing microalgae fermentation liquid> To produce biomass powder, the Schizochytrium fermentation broth was collected from the fermenter. Specifically, a Schizochytrium sp. strain was cultured in a 5L fermenter for 60 hours, with glucose as the carbon source, supplying 35% of the total culture broth. For seed culture, sterilized MJW02 medium was used in a 500mL flask, and the culture was carried out at 30°C and 150 rpm for approximately 20 hours. The seed culture flask was then dispensed and inoculated into a 5L fermenter, where it was cultured in sterilized MJW02 medium at 30°C, 500 rpm, 1.5 vvm, and pH 5-8.

[0038] Example 1. Production of biomass granules by core material type Example 1-1. Production 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 add biomass solids (g) and 50 g of lysine as the core material. The inlet air temperature was set to 100-130°C, and the internal temperature of the dryer was set to 60-80°C. 1400-1600 g of biomass fermentation liquor was spray-dried using the bottom spray coating method for approximately 2 hours 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 liquor added (g) and the amount of core material in the final sample (%) are shown in Table 1. In Table 1, the biomass solids (g) are calculated based on the solid content of the biomass fermentation liquor.

[0040] Example 1-2. Production of biomass granules containing methionine as a core substance Biomass granules containing methionine as a core material were produced in the same manner as in Example 1-1, using the contents listed in Table 1.

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

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

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

[0044] [Table 1]

[0045] Examples 1-6. Preparation of biomass granules containing soy protein concentrate as the core material After the fermentation, the biomass fermented 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 using bottom spray coating at temperatures between 60-80°C 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 (g) added and the content (%) of the core material in the final sample are shown in Table 2 below.

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

[0048] [Table 2] Comparative Example 1. Production of biomass granules containing no core material Using a fluidized bed granulator (Daesung Machinery), 1520 g of biomass fermentation liquid without a core material was spray-dried onto 190 g of biomass solids using a bottom spray coating method at temperatures between 60 and 80°C to form fluidized bed granules. The biomass solids content (g) and the amount of sprayed biomass fermentation liquid are shown in Table 3 below.

[0049] Comparative Example 2. Production of biomass granules containing biomass powder as the core material Biomass granules containing biomass powder as a core material were prepared using the same method 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. Evaluation of biomass granule characteristics based on the type of core material Experimental Example 1-1. Analysis of moisture content, angle of repose and fluidity of biomass granules depending on the type of core material 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, moisture content was measured using the loss on drying method in accordance with the general moisture content test method of the Food Code. 3-5 g of sample was accurately weighed, placed in a drying oven at 105°C for at least 3 hours, cooled in a desiccator at room temperature for at least 30 minutes, and then weighed. The sample was then dried again in the 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 calculating tan θ. The fluidity was evaluated using the angle of repose value according to Table 4 below. The results of the moisture content, angle of repose, and fluidity evaluation 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 that do not contain a core substance or biomass granules that contain 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 depending on the type of core material 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 Examples 1 and 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 filled with sample up to the top, and the sample stacked on top of the container was cut into a flat plate and then 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 as follows. After measuring the mass of the empty container, an auxiliary cylinder was attached on top and the sample was fully filled up to the top of the auxiliary container. Then, tapping was performed 1,000 times or more until there was no change in volume. After removing the auxiliary container, the sample was cut into a flat plate and its mass was measured. This was repeated five times or more until the difference in the measured values ​​was within 0.3%. The measured value was substituted into the following formula to calculate the packing density.

[0059] [Calculation formula] Packing density = (weight of the cylinder completely filled with powder after tapping (g) - weight of the cylinder (g)) / volume of the 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, the better the fluidity.

[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 Table 6 below. The natural density, packing density, Carr's index, and flowability evaluation results 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 densities and significantly lower Carr's index values ​​than biomass granules that did not contain a core substance or biomass granules that contained 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 the core material in the final sample To evaluate the difference in fluidity depending on the content of the core material, biomass granules containing 7.4% lysine 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 8.

[0066] Example 2-2. Preparation of biomass granules containing 9.1% lysine 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 9.1% lysine as the core material in the final sample were prepared using the same method as in Example 1-1, applying the contents listed in Table 8.

[0067] Example 2-3. Preparation of biomass granules containing 11.5% lysine 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 11.5% lysine as the core material in the final sample were prepared using the same method as in Example 1-1, applying the contents listed in Table 8.

[0068] Example 2-4. Preparation of biomass granules containing 16.4% lysine 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 16.4% lysine as the core material in the final sample were prepared using the same method as in Example 1-1, applying the contents listed in Table 8.

[0069] Example 2-5. Preparation of biomass granules containing 28.7% lysine 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 28.7% lysine as the core material in the final sample were prepared using the same method as in Example 1-1, applying the contents listed in Table 8.

[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 prepared 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 prepared 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 prepared 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 prepared using the same method as in Example 1-1, applying 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 prepared 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 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 using the same method 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 content of sprayed biomass fermentation liquid increased and the content 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 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 increased, i.e., the lower the content of core material in the final sample, the lower the Carr's index value and the higher the fluidity.

Claims

1. 1) Producing a biomass fermentation liquid or concentrate containing microalgae of the genus Schizochytrium or Thraustochytrium; and 2) spraying the fermentation liquid or concentrated liquid of 1) onto the core material to coat it, thereby forming biomass granules; A method for producing biomass granules, wherein the core material is soybean meal.

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

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

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

5. The method for producing biomass granules according to claim 4, wherein the biomass granules contain a core material and have a protein content of 15% by weight or more based on the total weight of the biomass granules.

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

7. A biomass fermentation liquid or concentrate containing a core substance and microalgae of the genus Schizochytrium or Thraustochytrium, the core material is soybean meal; The biomass granules having improved flowability, wherein the core material is coated with the biomass fermentation liquid or concentrated liquid.

8. The biomass granule according to claim 7, wherein the biomass granule contains 5 to 30 wt % of the core material based on the total weight of the biomass granule.

9. The biomass granule of claim 7 , 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.

10. The biomass granules according to claim 7, wherein the flowability of the biomass granules has been improved to a Carr's index of 15 or less.

11. The biomass granules according to any one of claims 7 to 10, wherein the biomass granules are produced by the production method of claim 1.

Images