Method for the production of a vegan leather alternative by making use of distiller's spent grain and brewer's spent grain

Abstract

The invention relates to the processing of distiller' s spent grain (DSG) and brewer' s spent grain ( BSG) extracted from alcohol production process and its application as a compound material in barley-based leather alternative, material obtained by this method of production and its use in the textile and related industries.

Description

[0001]METHOD FOR THE PRODUCTION OF A VEGAN LEATHER ALTERNATIVE BY MAKING USE OF DISTILLER’S SPENT GRAIN AND BREWER’S SPENT GRAIN DESCRIPTION FIELD OF THE INVENTION The invention relates to the processing of distiller’s spent grain (DSG) and brewer’s spent grain (BSG) extracted from alcohol production process and its application as a compound material in barley-based leather alternative. BACKGROUND OF THE INVENTION Animal leather and its vegan alternatives, fossil fuel leathers, have been proven to negatively impact the environment (McCartney, 2019). Livestock overgrowing for animal leather is using non-renewable resources of water and food, as well as emitting tonnes of greenhouse gases in the Earth’s atmosphere. Every year, total global emissions from livestock account for 7.1 gigatonnes of CO equivalent. Furthermore, according to FAO (2023), “About 44 % of livestock emissions are in the form of methane (CH). The remaining part is almost equally shared between nitrous oxide (NO, 29 %) and carbon dioxide (CO, 27 %).” Non-animal leather substitutes, which have been available in the market for years, are Polyvinyl Chloride or PVC and similar fossil fuel-based materials. PVC can be recycled which makes it partially sustainable, although its fossil fuel base has a greater impact on the environment than it can be reversed. Recycling PVC is either a mechanical or a chemical process, such as pyrolysis. The former poses a recycling challenge, due to the unpredictable composition of the recyclate. The latter, on the other hand, requires higher costs and leads to a low-value recyclate. As a result, only 0.25 % of PVC is recycled. As opposed to fossil fuel-based vegan leather, plant-based vegan leather alternatives are made by dehydrating plant waste, using less chemicals, i.e. polymers, in the process. Such polymers include polyurethane, polyamide, polyethylene, etc., but are not limited to them. Plant-based leather is an alternative to synthetic and traditional animal leather with an environmentally friendly impact. Plant-based leather can be made from a variety of cellulose based materials, including but not limited to cork, pineapple leaves, mango and mushrooms. In contrast to materials made from plants like cactus or pineapple, current innovation utilizes byproducts from the alcohol industry, some of which are occasionally repurposed as animal feed or otherwise discarded. One of the advantages over these plant based having in mind, for example, polyurethane as a polymer of choice, current innovation substitutes up to 80 % of the said polymer with barley malt, as opposed to using solely polyurethane. Consequently, the BSG-based leather is more environmentally friendly and partially biodegradable under the right conditions (e.g. temperature, humidity, aeration and time), with biodegradable being defined as the material’s ability to be naturally broken down by biological processes into simpler compounds over time, harmless to the environment. Prior art document WO2022189782 A1 (Plant-Based Flexible Material, Process for Preparation, And Uses Thereof, Publication Date 15.09.2022) describes preparation of the flexible material useful as an alternative to leather without the use of animal products. However, current invention differs from WO2022189782 A1 in several key aspects. Unlike the prior art use of carrageenan as a binder, which compromises durability, material disclosed in current invention utilises alternative with synthetic binders such as, but not limited to, PU with superior properties regarding degradability. Moreover, in WO2022189782 A1 compound materials are plant-based, which further lowers the durability, strength and heat-resistance. The use of compound materials derived from plant-based sources, particularly lignocellulosic biomass [used in WO2022189782], can lead to reduced durability, strength, and heat-resistance compared to materials of synthetic or mineral origin. This is primarily because lignocellulosic materials possess inherent properties that make them more susceptible to degradation, have a porous structure, and lack the structural integrity and heat-resistance of certain synthetic or mineral materials. Consequently, in applications requiring robust mechanical properties and heat resistance, such plant-based compounds may not perform as effectively. Alternatively, when combined with polymers or other matrices, BSG can provide increased strength and durability due to its fibrous nature. This reinforcement helps counteract the inherent weaknesses of some plant-based materials. Furthermore, while BSG is still a plant-based material and can be susceptible to heat and moisture, its incorporation into composite materials can offer better heat resistance compared to using the plant-based material alone. The matrix material, often a polymer, can provide a protective barrier, reducing the direct exposure of BSG to heat and improving overall heat resistance. Abrasion resistance of the material produced by current invention exceeds 100,000 cycles, significantly surpassing the prior art’s 30,000 martindales. Adhesion strength measures 30 N / 5 cm, while the prior art’s requirement is >4 N / 10 mm. Flexing crack resistance exceeds 150,000 cycles, far surpassing the lower limit value of 500 cycles. Coagulation in the manufacture of plant-based leather enhances its structural integrity, durability, and wear resistance by creating a solid and sturdy material. Lamination, on the other hand, while still providing decent structural integrity and durability, may not offer the same level of robustness and wear resistance as coagulated plant- based leather. By combining coagulation and lamination processes in the manufacture of plant-based leather, manufacturers can achieve a material with enhanced structural integrity, customizable properties, improved durability and wear resistance, and versatility in design and functionality. Due to consequential enhanced structural integrity, durability, and wear resistance obtained by incorporating coagulation in the manufacturing process, as opposed to CN112810260 A (Synthetic Leather Based on Plant Crops, Preparation Method and Application of Synthetic Leather, Publication Date: 18.05.2021) and CN113308908 A (Vegetable Lether Using Plant Fibers and Manufacturing Method of Vegetable Leather, Publication Date: 27.08.2021), the current invention provides significant advantage over said prior art. Furthermore, the current invention contains a binder, which ensures strong interlayer bonding, preventing delamination and improving longevity, whereas material in CN112810260 A lacks that aspect. Document WO2022213205 A1 (Plant-Based Leather Substitute Material, Publication Date: 13.10.2022) provides a non-vulcanized rubber on the textile substrate. By using a higher concentration of non-vulcanized natural rubber, the breathability and abrasion-resistance properties are compromised. Breathability is the essential property of a material that allows air and moisture vapour to pass through, thereby enabling comfort and preventing the accumulation of heat and sweat. Current invention shows significant advantage over WO2022213205 A1 in terms of breathability, where the said property is lower due to non- vulcanized rubber’s higher molecular weight and greater density, which results in a more tightly packed structure and reduced permeability of air through the material. Moreover, high concentrations of non- vulcanized rubber result in a softer and more pliable material, which is then more prone to wear and damage and consequently lowers abrasion- resistance of the competitor’s material. The state of art document US2022316133 A1 (Plant-Based Biodegradable Synthetic Leather, Publication Date: 06.10.2022.) does not incorporate the use of waste materials but instead utilizes virgin bamboo fibers, which leads to a greater negative environmental impact compared to current invention, since bamboo cultivation demands high water availability and consumption. Therefore, irrigation systems are necessary for bamboo growth in areas where sufficient water is unavailable. The absence of plant-based waste use in US2022316133 A1 formulation results in a product that essentially combines polyurethane with plant textile, akin to a cotton backing. Current invention exhibits different characteristics and advantages over JPH04100985 A (Production of Synthetic Leather, Publication Date: 02.04.1992). In comparison to the lamination process described in said prior art, current lamination techniques offer enhanced flexibility in achieving various textures based on the utilised polymer type. Furthermore, the current invention ensures a high level of durability, rendering it well-suited for applications involving prolonged handling and wear. Additionally, it enables the application of glossy or matte finishes through lamination or UV coating, providing increased aesthetic versatility. Lastly, JPH04100985 A does not use plant matter in its formulation, rendering it far less sustainable in comparison to current invention. To minimise waste and add to sustainability of the alcohol production industry, current solution utilises barley malt leftovers, also known as Brewer’s Spent Grain (BSG) or Distiller’s Spent Grain (DSG). Documents WO2023012841 A1 (Process for Treating of Brewing Industry By-Products, Publication Date: 09.02.2023), CA2155042 A1 (Process for the Preparation of Protein-Rich Product from Brewer’s Spent Grain, Publication Date: 05.02.1996) and EP0443813 A1 (Protein-rich Products of Brewer’s Spent Grain Origin, Publication Date: 28.08.1991) also describe recovering BSG, although their approach lacks innovation as it fails to introduce a novel product like the current invention. Furthermore, they do not repurpose the BSG, therefore their environmental impact falls short compared to this invention. What’s more, using malt grain as animal feed may not be the most optimal option due to the high level of protein degradation indicated by the Kolbach index, which ranges from 38 to 42 %. Several other reasons contribute to why malt grain may not be the best choice for animal feed. Firstly, the high protein degradation in malt grain means that a significant portion of the protein content has already been broken down or lost during the brewing process. This leads to a reduction in the overall nutritional value of the grain for animals. Secondly, animals require a balanced diet with sufficient protein to support their growth, health, and reproduction. Malt grain with its reduced protein content may not provide the necessary protein levels to meet the animals' nutritional requirements adequately. Moreover, proteins in animal feed should ideally have a balanced amino acid profile to support various physiological functions. The protein degradation in malt grain may alter the amino acid composition, leading to an imbalanced feed lacking essential amino acids. Additionally, apart from protein, animals also need energy-rich feed to maintain their body weight and perform daily activities. Malt grain, being a byproduct of the brewing process, may have lower energy content compared to dedicated animal feed ingredients. Furthermore, during the brewing process, certain anti-nutritional factors may develop in malt grain, which could have adverse effects on animal health and digestion. These factors might reduce feed efficiency and nutrient absorption. The high level of protein degradation might also affect the digestibility of malt grain in animals. Reduced digestibility can lead to inefficient nutrient utilization and potentially cause gastrointestinal disturbances. Considering its reduced nutritional value and possible need for additional supplements to meet the animals' dietary requirements, using malt grain as animal feed may not be cost-effective. What’s more, alcohol brewing industry has several negative environmental impacts. Water usage in the beer brewing process is substantial, with around 5-8 litres needed to produce 1 litre of beer, straining local water resources, especially in water-scarce regions. Moreover, according to Fillaudeau (2006) each ton of produced beer generates from 3 to 10 tons of brewery wastewater (BWW). Wastewater generation from brewing contains pollutants, posing risks to water bodies and aquatic life if not properly treated. Apart from improving the sustainability of the alcohol production industry, barley is also chosen due to its high fibre content and low amount of sugar. Fibre content is known to improve durability, while low sugar amounts eliminate the possibility of moulding as opposed to other plant-based leathers. In addition, low sugar content also decreases the nutritional value, limiting its potential alternative use as food and feed. Another common utilization of BSG, or more precisely the discarded yeast, is in animal feed. Even though Brewer’s spent yeast is a cheap and readily available source of protein, its high level of RNA poses a major challenge for human consumption. An excess of RNA in the diet can potentially cause health conditions, such as gout, due to a possible increase of uric acid in the bloodstream. The release of excess gas by animals, used for the production of leather, contributes to ozone depletion and compromised air quality, making the current invention greatly favourable to animal leather production. Additionally, the barley malt pomace undergoes decomposition, releasing gases into the atmosphere and promoting bacterial growth. This underscores the greater significance and potential for valorisation and repurposing of this byproduct. High fibre content and low sugar content make barley malt an ideal cellulose-based material for BSG-based leather production due to the minimum risk of moulding and a high amount of waste recovery. When considering resource utilization, the described method proposes a more sustainable, ecological and environmentally compatible solution than known from the prior art. Current innovation addresses two critical aspects: sustainability and durability. By valorising byproducts instead of relying on raw materials grown specifically for this purpose, the environmental impact of the alcohol and fashion industries is significantly reduced. Furthermore, the use of barley malt pomace, a byproduct commonly used for cattle feed, becomes even more valuable as the cattle industry faces a decline. This not only prevents waste but also maximizes the utilization of available resources. Regarding durability, our approach incorporates, for example, a smaller particle size and a PC-PU blend, resulting in a synthetic leather product that exhibits enhanced durability and longevity. In contrast to previous methods such as orange leather and cactus leather production, current invention deviates from using hydrogen peroxide or sodium hydroxide in the process. By eliminating the reliance on these chemicals, it reduces potential environmental impacts and ensures a more sustainable production process. Current innovation focuses on alternative techniques that achieve desired results without the need for these specific substances. In summary, current innovation offers a sustainable solution that addresses environmental concerns, utilizes valuable byproducts, and ensures the durability of the synthetic leather product. Through a thoughtful and eco-conscious approach, current invention contributes positively to the industry while minimizing the impact on the environment. BRIEF DESCRIPTION OF THE INVENTION Present invention discloses method for obtaining vegan leather alternatives 1. Method for obtaining vegan leather alternatives comprising following steps: a) malting barley for alcohol productions; b) isothermal mashing; c) cooking; d) washing; e) filtration of the leftover husk; f) drying; g) milling; h) sieving; i) mixing; j) mixing organic solvent with the mixture obtained by step i); k) mixing the product obtained by step j) with dissolved polymer in the concentrations of dry polymer content of 20 -50%; l) pumping and uniformly spreading the product of the step k) and the remaining portion of organic solvent onto the textile; m) performing wet process for production comprising following steps: (i) applying adhesive layer to the product obtained from step l); (ii) application of polymer; (iii)planting the barley malt powder and polymer mixture obtained from step i) on the top layer; (iv) applying curing process; or performing dry process for production comprising following steps: (v) barley malt powder and polymer mixture obtained from step i) is heated until molten and then applied to the product obtained by step l); (vi) coated fabric obtained from step (v) is passed through a series of rollers which apply pressure and heat to activate the adhesive properties of the polymer and bond it; n) wet coagulation process or dry coagulation process and / or wet lamination process or dry lamination process; o) distillation; p) drying; q) coating with polymer layer; r) lamination finishing process; s) pigmentation; t) digital print. The invention further discloses vegan leather alternative material obtainable by said process as well as its use in the textile and other related industries. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1. Sugar concentration at different isothermal rests, with optimal temperature ranges of sugar-relevant enzymes indicated at the top of the figure (Laus, A., Endres, F., Hutzler, M., Zarnkow, M., Jacob, F. 2022) Figure 2. Weight percent of material in fraction as a function of particle size Figure 3. Cumulative weight percent less than certain particle diameter DETAILED DESCRIPTION OF THE INVENTION Definitions Barley malt in any form is being referred to as raw material throughout this specification. Barley malt is called Brewer’s Spent Grain (BSG) or Distiller’s Spent Grain (DSG) after the process of boiling in strike water. Barley refers to the seed and malt is the result of barley seed sprouting through a process called malting. Malting is the process of soaking, germinating and drying grain. Barley is the brewer's preferred grain for several reasons. Firstly, barley exhibits effortless germination even in colder temperatures. Consequently, barley naturally possesses elevated levels of crucial starch-degrading enzymes, namely beta- and alpha-amylases, due to the germination process. These enzymes play a pivotal role in facilitating the inherent ethanol fermentation process when employed in a brewery or distillery. Secondly, barley possesses a suitable husk, which guarantees smooth wort separation during the brewing process in the brewhouse. Grain will also be referred to as “cereal crops”. Cereal are grasses which produce grain, not to be confused with animal leather which is often referred to as grain leather. Grain in non-vegan leather refers to the way animal hide looks depending on the epidermis layer. Grain in animal leather is divided into 3 layers: full grain, top grain and genuine or suede. As stated in The Potential of Brewer’s Spent Grain in the Circular Bioeconomy: State of the Art and Future Perspectives (2022), the main components of BSG are hemicellulose (19 - 20 % dry matter), cellulose (15.2 - 28.7 % dry matter), lignin (3.35 - 21 %), proteins (18.5 - 24.7 % dry matter), lipids (8.4 %), starch (5.3 %), and ash (3.7 %). Additionally, BSG contains phenolic compounds that are distributed among different parts of the barley kernel. by making use of distiller’s spent grain and brewer’s spent grain according to current invention comprises following steps: 1) Processing of raw organic compound materials In order to minimise moisture content, barley malt goes through a drying process, which includes but is not limited to sun drying, hot air drying, contact drying, infrared drying, freeze-drying, fluidized bed drying, and dielectric drying depending on location, resources and energy consumption at the time. Dry grain is then milled in a wet or dry milling process, to a particle size from 1 to 250 μm with a median size under 100 μm. Smaller particle sizes enable a higher percentage of plant powder in the polymer dispersion, ranging from 20 to 80 % which allows for greater flexibility in achieving desired properties of the finished material. Malting The utilization of barley malt in lieu of raw barley holds significant importance owing to its inherent association with the malting process and the consequential utilization of sugars and nutritional constituents in the context of human consumption. The initial phase involves immersing barley in water at a controlled temperature ranging from 12 to 26 °C, typically spanning a duration of 3 to 5 days, contingent upon the specific grain type, to initiate the germination process. Subsequently, prior to the emergence of roots from the grain, it is extracted from the water and subjected to drying procedures aimed at arresting the germination process. This drying process entails the application of air and heat, with temperatures varying between 15 and 50 °C, depending on the intended alcoholic product. The process of malting bears significance by facilitating the opening of the grain and subsequent release of nutrients into the strike water for consumption, thereby minimizing the wastage of otherwise valuable constituents. The leftover husk is used for filtration purposes of the alcoholic beverage, after which it is removed from the brewing and distilling process and processed for BSG-based leather due to the high fibre content and low nutritional value. Table 1. Comparative fibre concentrations of barley malt, apple pomace and grape pomace Fibre concentration, g / 100 g The differential fibre concentrations observed in barley malt, apple pomace, and grape pomace, shown in Table 1, serve to underscore the contrasting nutritional characteristics of these byproducts, emphasizing the higher fibre content present in barley malt. On average, barley malt contains 6x more fibre content compared to the two pomaces, which evidently makes it a much preferable substrate for plant based leather. Malting plays a crucial role in this case because of enzyme activation and sugar formation. The reason is that malting involves the process of germinating cereal grains, such as barley, under controlled conditions. During germination, enzymes present in the grains are activated, which are essential for converting the starches in the grains into fermentable sugars. These enzymes, particularly amylase and protease, break down the complex carbohydrates and proteins in the grains into simpler forms that yeast can utilize during fermentation. Regarding the sugar formation, the enzymes activate during malting, specifically alpha-amylase and beta-amylase. The enzymes then convert the starches in the malted grains into various sugars. Alpha-amylase breaks down the starch molecules into maltose, a disaccharide (consisting of two glucose molecules), while beta-amylase breaks down the starches into maltose and other fermentable sugars like glucose and maltotriose. These sugars are the primary food source for yeast during fermentation, which affects the possibility of moulding, described in more detail in chapter Correlation of sugar amount and moulding. After the desired amount of enzymatic activity is achieved during germination, the malted grains are kilned to stop further growth and deactivate the enzymes. Mashing In isothermal mashing, the optimum action of various enzymes is achieved at certain temperatures. This can be seen from the curves of the different sugar concentrations, shown in Figure 1. The course of the maltose concentration followed the optimum temperature of the α- and β-amylases. The concentration of maltose increased continuously in a temperature range from 41 to 57 °C until it reached a relatively constant peak of 73.06 g / L between 59 and 71 °C on average. This reflects the enzymatic action of α- and β-amylases on amylose and amylopectin. Greatest advantage of isothermal mashing is that it provides consistent conditions for the enzymatic conversion of starches to sugars. This results in a higher yield of fermentable sugars, meaning that there is lower sugar saturation in the final barley malt waste, which minimizes moulding possibility. However, step mashing can be more time-consuming and requires careful monitoring of the mash temperature to ensure that the enzymatic reactions proceed correctly. In terms of sustainability, isothermal mashing is generally considered to be more efficient and environmentally friendly than step mashing, due to its ability to save energy and water by maintaining a consistent temperature throughout the mashing process, thereby reducing resource consumption and associated environmental impacts. In contrast, step mashing requires more energy to heat and cool the mash at different stages, which can increase energy consumption and greenhouse gas emissions. Cooking Barley malt is then transferred to hot water, known as “strike water”, ranging from 70 to 78 °C which helps turn starch into simple sugar, leaving behind grain leftovers called Brewer’s Spent Grain (BSG) or, depending on the type of alcohol being developed to, Distiller’s Spent Grain (DSG). It’s a perishable product due to high water content and is produced in large quantities. Barley malt is collected from breweries after being removed from the brewing process, after boiling and before fermentation. This way there is no need to use temperature manipulation techniques to stop the process of fermentation such as storing the processed raw material at below 0°C or boiling at temperatures over 70°C for over 20 minutes. This makes for an additional layer of sustainability and a positive environmental impact as it lowers energy consumption. The moisture content of BSG at this stage is between 60 and 85 %, depending on the technique of removal. Because of the high moisture content and high temperature of barley malt, it is important to store the used grain in burlap sacks, or an equivalent material regarding airflow, as processed barley malt is a frugal ground for bacterial reproduction, causing mould and decomposition. Wet BSG and DSG are usable for 48 hours if being stored in an aerated, cool place (<10 °C). Washing Subsequent to its extraction from the brewing tank, barley malt undergoes a washing process aimed at diminishing the sugar content from an initial value of 0.8 g / 100 g to a reduced level of 0.1 g / 100 g. The waste sugar can be utilized in various ways, thus yet again contributing to the concept of circular economy. Some potential applications lie in the production of biogas, bioethanol, food, feed or biochemicals like organic acids and enzymes, as well as its use to fertilize crops. The procedure of washing barley malt holds considerable significance due to the positive associations established between sugar content and the occurrence of mold formation, particularly in applications pertaining to the fashion and other industries where plant-based leather is exposed to environmental factors such as rain, sweat, and other sources of moisture. Correlation of sugar amount and moulding Apple pomace, grape pomace, and barley pomace are all byproducts of food processing and have different compositions, including different amounts of sugar. Apple pomace is the pulp and fibre leftover from apple juice production. It typically contains around 20 to 30 % sugar, mostly in the form of fructose and glucose. Grape pomace is the skin, seeds, and stems leftover from winemaking. It also contains sugar, but typically in lower amounts than apple pomace, around 10 to 20 % sugar, mostly in the form of glucose and fructose. Barley pomace is the residue leftover from the brewing process, and it has a lower sugar content than the other two. Barley pomace contains around 2 to 6 % sugar, mostly in the form of maltose. Table 2 shows the amount of sugar in barley, barley malt, and washed barley malt. Table 2. Comparative amount of sugar in barley, barley malt, and barley malt washed Amount of sugar, g / 100 g There is a positive correlation between the amount of sugar and mold growth. Mold is a type of fungus that requires moisture and a source of nutrients to grow, and sugar provides a readily available food source for mold. The more sugar that is present, the more likely it is that mold will grow. This is why foods that are high in sugar, such as baked goods, candy, and syrups, are more prone to developing mold than foods with lower sugar content. Additionally, the moisture content of a food also plays a role in mold growth, as mold thrives in damp environments. Therefore, it is important to store sugary foods in a dry environment to prevent mold growth. Drying Dehydration After washing, barley malt is then dehydrated in industrial size dehydrators- stackable dehydrators, shelf dehydrators or cabinet dehydrators, powered by gas or electricity. The process of drying can also be accomplished by hot air drying, contact drying, infrared drying, freeze-drying, fluidized bed drying, and dielectric drying, and through the utilization of UV light or natural sunlight, as is the case with cactus leather. Although employing natural sunlight is considered highly sustainable and energy-efficient, it is constrained by its inherent dependence on prevailing weather conditions and geographical location, rendering it unreliable. Furthermore, this approach poses challenges in terms of scalability, impeding its widespread application, limiting the positive impact of materials produced in this invention. Granulation of the grain at this stage is heterogenous, ranging approximately from 1 to 7 mm, depending on the type of barley used. Because of this, standard dehydrating shelves need an additional netting in order to hold the smaller seed particles. Netting has to be temperature resistant (over 70°C) to avoid melting onto the barley malt and to hold shape so that the thickness of the barley malt layer can be accurately measured. Silicone dehydrator sheets ought to be avoided as they prolong the drying process and dehydrate grain unevenly. Spray drying Spray drying is a widely employed method for transforming liquid or slurry-like substances into dry, powdered form. The process involves the following steps: 1. Atomization: The liquid or slurry is introduced into a spray dryer chamber. Atomization is the first stage, where the material is converted into fine droplets. This can be achieved using various techniques such as rotary atomizers, pressure nozzles, or centrifugal atomizers. The goal is to create a large surface area for efficient drying. 2. Drying: The droplets are exposed to a stream of hot air or gas within the drying chamber. The hot air rapidly evaporates the moisture from the droplets, allowing them to dry. The drying process occurs through simultaneous heat transfer, mass transfer, and evaporation. The temperature and airflow are carefully controlled to achieve optimal drying without causing degradation or overheating of the product. Due to the evaporative cooling effect, the inlet temperature on this type of dryer is normally quite high relative to the dry products’ temperature limitations. Typical inlet temperatures for spray dryers range from 200 to 540°C depending on the application. The higher temperatures are normally for inorganic salt drying, and the lower temperatures are normally for organic temperature-sensitive products. 3. Particle Separation: Once the droplets have dried completely, the resulting powder or particles are separated from the exhaust air. This separation is typically accomplished using cyclones or bag filters. The dried particles are collected for further processing or packaging, while the remaining exhaust air is usually passed through filtration systems to remove fine particles before being discharged. Dehydration offers the advantage of minimizing yeast fermentation and is typically preferred to be carried out before dry milling processes. On the other hand, spray drying demonstrates increased efficacy when employed after wet milling operations. This distinction arises from the effect of particle size, whereby smaller particles tend to exhibit a higher tendency for agglomeration. Milling The milled BSG or DSG, obtained through either wet or dry processing, exhibits a particle size ranging from 1 to 1000 μm, while its Mohs hardness scale is below 2 out of 10. Achieving a particle size below 100 μm is desirable as it increases the proportion of plant-based content in the formulation, in contrast to larger particles that diminish the abrasion resistance of the top coat and impact the final material's texture. Moreover, different properties of the material are obtained with different granulations. Dry milling typically involves reducing the size of materials through direct contact between particles, while wet milling entails dispersing the material in a liquid and using solid grinding elements to achieve size reduction. Wet milling, alternatively referred to as wet grinding, is a complex procedure in which particles suspended in a liquid slurry are dispersed by means of shearing or crushing while immersed in the liquid medium. Once the milling is finished, these particles can be utilized immediately or dried and separated for incorporation into other products. Although wet milling is more complex due to the liquid component, it has the capability to reduce a product into finer particles, allowing for a wider range of byproducts and potentially enhancing the physical properties of the final product. In contrast, dry milling does not involve any liquid and is primarily employed for reducing the particle size of dry materials such as powders and granules. The husk and endosperm are two components of a grain such as barley, wheat, or rice. The husk is the outer layer of the grain and is typically dry and fibrous. It serves to protect the inner parts of the grain from external damage and moisture, and also provides a natural filter bed during the brewing process. In beer brewing, the husk is important for providing filtration and clarity to the finished beer. The endosperm is situated within the husk. It is considered the primary component of the grain, as it is the starchy part that contains most of the nutrients and energy needed for the growth of the plant. In milling, the endosperm is separated from the rest of the husk and used to produce various food products, such as flour, cereals and pasta. In beer brewing, the endosperm is used to produce the sugars and other nutrients needed for the yeast to ferment and produce alcohol. Sieving Sieving is a critical process employed in various industries to separate and classify materials based on their particle size. It serves important purposes such as quality control, particle size analysis, and impurity removal. By separating particles based on size, sieving helps identify and remove oversized or undersized particles, maintaining product quality and adhering to regulatory standards. In order to achieve homogeneous powder in current invention, milled BSG or DSG is sieved through a fine sieve with openings smaller than 100 μm. Particle size analysis is another significant application, providing valuable information about material characteristics, optimizing processes, and ensuring consistency in production. In the current invention, particles from 100 to 350 μm are returned to the mill in a dry milling process. Particle size distribution data can be presented in both tabular and graphical formats. Tabular data show the amount of material in each measured fraction, and cumulative percentages smaller or larger than certain values are often included. Graphs are then generated to determine the mean particle size and other fractiles. One type of graph shows the weight percent of material in each fraction as a function of the midpoint diameter of the fraction (Figure 2). Another type of graph, using a cumulative probability scale, shows the amount of material less than a given particle diameter (Figure 3). Skewed data can be treated using a logarithmic scale. Graphical representation is useful for comparing samples and assessing the breadth of the particle size distribution. Impurity removal is another key objective of industrial sieving. By effectively separating impurities or foreign matter from materials, sieving enhances product purity, safety, and overall value. Sieves, essential tools in this process, come in different types to suit specific applications. The most common types include vibratory, gyratory, and centrifugal sieves. Vibratory sieves utilize vibration to convey and separate materials, making them suitable for high- capacity applications. Gyratory sieves use a gyratory motion to achieve efficient sieving and are often preferred for delicate or difficult-to-screen materials. Centrifugal sieves employ centrifugal force to separate materials based on particle size, making them ideal for applications where high-speed rotation is necessary. When selecting sieves, various factors must be considered, such as mesh size and shape play a critical role in determining sieving capacity and accuracy. Mesh size refers to the number of openings per linear inch in the sieve screen, and so the finer the mesh sizes, the smaller the separated particles. Along with size, mesh shape also plays a role in sieving efficiency. Different mesh shapes, such as square, rectangular, or circular, have varying open area percentages. The choice of mesh shape affects the sieving capacity, as it determines the amount of material that can pass through the screen. The shape of the mesh can impact the flow of particles and the overall efficiency of the sieving process. The design of sieving equipment also influences the efficiency and effectiveness of the sieving process. Factors such as vibration intensity, screen inclination, and flow rates contribute to overall performance. Vibration intensity affects the movement and stratification of particles on the sieve, promoting efficient separation. Adjusting the screen inclination angle can impact the flow of material across the sieve, optimizing sieving efficiency. Proper control of flow rates ensures that the material is evenly distributed across the sieve screen, enhancing accuracy and preventing overloading. Mixing Mixing refers to the process of combining two or more substances or components to create a uniform and homogenous mixture. The purpose of mixing is to ensure that all the components are thoroughly combined, resulting in a consistent and desired final product. In industrial settings, mixing is often performed using industrial mixers that include, but are not limited to: horizontal ribbon mixer, paddle mixer, tumbler mixer, emulsifier, drum mixer, static mixer and planetary mixer. These machines provide the necessary mechanical energy to disperse, dissolve, or distribute the components evenly throughout the mixture. Efficient mixing is essential for achieving product uniformity, maintaining product quality, and optimizing production processes. It helps to achieve consistent properties, such as colour, texture, viscosity, and chemical composition, while also ensuring the desired product characteristics and performance. 2. Vegan Leather Alternative Production Fuel-based or synthetic leather is commonly created through a process that involves saturating textiles with a certain type of polymer, forming a bond that imparts similar mechanical properties and tactile feel to genuine leather. In contrast, the process of BSG-based and DSG-based leather production substitutes up to 80 % of a certain polymer, e.g. polyurethane (PU), with barley malt, making it more sustainable and biodegradable, due to the lower PU content. The production begins with the combination of the solvent dimethylformamide (DMF) and barley powder, which are then mixed with dissolved polyurethane. The resulting mixture, with a dry PU content ranging from 20 to 50 % and the remaining portion being DMF, is pumped onto a textile and uniformly spread. The viscosity of the PU is a crucial factor influencing the textile's absorption capacity. Lower viscosity leads to increased solution absorption, while higher viscosity results in reduced absorption. Controlling the viscosity of the PU in the fabric coating process is crucial to achieve desired properties such as absorbency, coating thickness, adhesion, flexibility, mechanical strength, and surface smoothness in the final material. Besides polyurethane, polymers most used in the production of coated and coagulated barley-based fabrics are the following: rPU (recycled polyurethane), TPU (thermoplastic polyurethane), rTPU (recycled thermoplastic polyurethane) PC-PU (polycarbonate-polyurethane) , rPC- PU (recycled polycarbonate-polyurethane) PA (polyamide), rPA (recycled polyamide), PP (Polypropylene), rPP (recycled polypropylene), PE (polyethylene) rPE (recycled polyethylene), PLA (polylactic acid), rPLA (recycled polylactic acid), PHA (polyhydroxyalkanoates), rPHA (recycled polyhydroxyalkanoates), PHBV (poly(3-hydroxybutyrate-co-3-hydroxyvalerate)), rPHBV (recycled poly(3-hydroxybutyrate-co-3-hydroxyvalerate)), bio-based polymers, vegetable oil-based polymers and natural and synthetic latexes. BSG-based leather production includes lamination and coagulation processes, respectively. Lamination (L) can be utilized both as a method for the merging of the fabric substrate and the coating, i.e. polymer + barley malt, as well as a finishing method (Lf) that creates a material with desired external texture. Coagulation (C) is used to solidify a synthetic polymer mixture, creating a foam-like material on a fabric substrate. Lamination and coagulation both have two possible variations - wet and dry. Lamination used for the finishing of the material has three possible variations - cold-melt, hot-melt and UV. Consequently, the production can be possible in the following different combinations: 1. wet C only 2. dry C only 3. wet L only 4. dry L only 5. wet C + cold-melt Lf 6. wet C + hot-melt Lf 7. wet C + UV Lf 8. dry C + cold-melt Lf 9. dry C + hot-melt Lf 10. dry C + UV Lf 11. wet L + cold-melt Lf 12. wet L + hot-melt Lf 13. wet L + UV Lf 14. dry L + cold-melt Lf 15. dry L + hot-melt Lf 16. dry L + UV Lf C - coagulation L - lamination Lf - lamination as a finishing method In the wet process of lamination of BSG-based and DSG-based leather production, the initial step involves applying an adhesive layer to a fabric substrate, followed by the application of polymer and plant, i.e. barley malt powder dispersion on top. After the coating is evenly spread over the fabric, the material undergoes a curing process, allowing the adhesive to set and the polymer to solidify, resulting in a strong bond. Alternatively, the dry method of lamination of BSG-based and DSG-based leather involves the use of heat and pressure to bond a synthetic polymer layer to a fabric substrate without the need for any liquid adhesives or solvents. In this method, a layer of polymer and plant, i.e. barley malt powder is applied to the fabric substrate using a hot-melt coating process, where the polymer is heated until it becomes molten and then applied to the fabric. The coated fabric is then passed through a series of rollers, which apply pressure and heat to activate the adhesive properties of the polymer and bond it to the fabric substrate. Another method is the wet process of coagulation, that involves the use of a coagulant solution to solidify a synthetic polymer dispersion into a coherent layer. The coagulation process starts with soaking the chosen permeable or semi-permeable fabric in the mixture of polymers, additives such as foaming agents, antibacterial agents and other agents based on desired properties as well as processed grain leftovers which results in the formation of a foam-like material. Key step is mixing barley malt powder with a solvent such as DMF rather than water or liquified polymers in order to avoid granulation. Moreover, the wet coagulation technique involves the use of specific ions, such as aluminium (Al ) or calcium (Ca ), which play a vital role in the coagulation process. These ions act as coagulating agents, facilitating the precipitation and solidification of suspended particles within the synthetic effluent. As a result, the alkalinity of the effluent is effectively reduced, leading to a subsequent decrease in pH levels. Furthermore, during the coagulation process, the ionic dispersion and coagulating media present in the impregnated sheet are effectively removed. This removal is crucial for achieving a purified and clarified synthetic effluent. By eliminating these components, the resulting sheet gains improved stability and enhanced properties suitable for further processing or utilization in various applications. With another method, in the dry coagulation process the textile is impregnated with polymer and barley malt powder, dissolved in DMF and the impregnated textile is subsequently dried. Because of the organic solvent, a porous flexible structure is developed upon coagulation resulting in a flexible leather-like material. In addition, mixing barley malt powder with DMF rather than water or liquified polymers is preferable to avoid granulation. Following coagulation, an internal distillation process is employed to remove the DMF from the material. Within a distillation apparatus, the coated material is subjected to temperatures above DMF’s boiling point (153 °C), causing the DMF to vaporize. The vapour is then condensed and collected, leaving behind the purified material free from DMF, thereby ensuring the removal of residual solvent from the fabric, enhancing its quality and reducing potential environmental and health hazards. The water used for washing is recycled back into the system with only 2 % annual loss, and is kept at around 26-28 °C all year round. The material then undergoes squeezing rollers to facilitate drainage, after which it is dried in an oven heated with oil at a temperature of 180 °C. Notably, the PU is dissolved at the working temperature of the machinery, at approximately 70 °C, thereby rendering the process even more sustainable compared to the process of pre-heating the PU. After drying, the material is coated in a dry process with a polyurethane layer to create a finished BSG-based leather product. The wet process is commonly used in the production of plant-based leather because it allows for greater control over the properties of the final material, such as its thickness and texture. Another method of BSG-based leather production includes wet milling the barley malt into particles ranging from 1 to 350 µm into a slurry with moisture level of 60 to 85 % and adding the natural or synthetic additives based on the required properties of the material with constant mixing in one of the aforementioned industrial mixers until it forms a homogeneous mixture. The additives can be, but are not limited to previously described in factory production of plant-based leather. The slurry is then placed into, for example, dehydrators for a range of 6 to 12 hours depending on the thickness of the slurry or subjected to one of the aforementioned drying methods to lower the moisture level to 1 to 30 %, based on desired properties. The drying methods include, but are not limited to sun drying, hot air drying, contact drying, infrared drying, freeze-drying, fluidized bed drying, and dielectric drying. After drying, the material goes through a lamination process, for example applying a film or protective spray until a topcoat is cured. Same finishing and embossing methods apply as in every other described processes of current invention. A similar method includes spreading the unmilled BSG slurry and additives onto the dehydrating trays, in the same form they were collected from the brewing or distilling facility. This method lowers the energy consumption needed for milling, thus making the process more sustainable and environmentally friendly. Because of the larger particle size and roughness and orientation of the grain, multiple layers of the topcoat need to be applied in order to counter the lowered abrasion resistance of the surface. Furthermore, larger particle size lowers flexibility, thus limiting application. Particle analysis of the material obtained with previous inventions is given in Table 3, where all the values are weighted by volume fraction. Table 3. Statistical description of particle analysis which resulted in poorer durability N = Mean σ d d d The material obtained with all methods consists of multiple layers, a base heat-resistant fabric that can endure temperatures up to 195°C without changing physical or chemical properties or catching fire, such as cotton and cotton blends. However, various materials can be used for backing in synthetic leather production, depending on the desired properties and intended applications of the final product. Some common materials used for backing in synthetic leather include, but are not limited to woven backing, non woven backing, foam backing and knit backing. Fabrics like polyester, nylon, or cotton can be used as backing materials for synthetic leather. These fabrics provide added strength, stability, and flexibility to the synthetic leather, enhancing its overall durability and tear resistance. Non-woven materials, such as spunbond or needle-punched fabrics, are often used as backing in synthetic leather. These materials offer good dimensional stability, tensile strength, and tear resistance while providing a soft and comfortable feel. Foam materials, such as polyurethane (PU) foam or ethylene-vinyl acetate (EVA) foam, can be used for backing in synthetic leather. Foam backings provide cushioning, support, and improved comfort, making them suitable for applications like upholstery, footwear, and padded accessories. Knitted fabrics, typically made from polyester or nylon yarns, are sometimes used as backing materials in synthetic leather. Knit backings offer flexibility, stretchability, and breathability to the synthetic leather, making them suitable for applications that require a high degree of comfort and flexibility. Cellulose plays a crucial role in the production of BSG-based leather, significantly impacting its properties. Firstly, it contributes to the strength and durability of the material due to its fibrous and robust nature, providing structural integrity and resistance to tearing and wear. Additionally, the presence of cellulose gives the BSG-based leather a texture and feel reminiscent of natural leather, which can be further tailored through different manufacturing processes. Moreover, cellulose-based plant materials offer breathability, allowing air circulation through the fabric and ensuring comfort, especially in warmer conditions, by regulating temperature and moisture. Their absorbency property adds to the comfort, as plant- based leather can absorb and release moisture to create a natural feel. Another advantage is its eco-friendliness and potential for biodegradability, as cellulose is sourced from renewable plant sources, reducing the environmental impact compared to synthetic materials. Cellulose's ability to take dyes and finishes allows manufacturers to achieve a wide variety of colours and finishes for plant-based leather products. Its sustainability as a renewable resource further positions it as an environmentally responsible alternative to traditional animal leather, which contributes to deforestation and requires animal husbandry. Additionally, cellulose-based materials offer versatility in processing methods, enabling various techniques like coating, laminating, and embossing, leading to diverse design possibilities for plant-based leather products. The ease of manufacturing cellulose- rich materials facilitates scalability and commercial viability in the production of BSG-based leather. Another excellent property of cellulose-based plant materials is that they are often hypoallergenic, making BSG-based leather suitable for individuals with sensitive skin, setting it apart from some synthetic materials and certain types of animal leather. Additives In synthetic leather production, various additives can be added to achieve desired properties and enhance the performance of the material. Some of the common additives used include softening, anti- foaming, anti-flammability, UV protection, waterproofing agents, colorants and pigments, antioxidants, antimicrobial agents and stabilizers. Softening agents are typically added to synthetic leather to improve its flexibility, suppleness, and overall tactile feel. They enhance the leather-like texture and make the material more comfortable to touch. Anti-foaming agents are used in wet coagulation processes of synthetic leather production. During the coagulation process, when the impregnated fabric is immersed in water, foaming can occur due to the release of gases or air bubbles. These agents also help prevent or reduce foaming, ensuring a smooth and consistent coagulation process. Synthetic leather can be treated with anti-flammability agents to improve its fire-resistant properties. These agents help reduce the flammability of the material and enhance its safety. Furthermore, anti-flammability agents are particularly important for applications where fire resistance is a critical requirement. UV protection agents are added to synthetic leather to provide resistance against UV radiation, for example from the Sun. These agents help prevent fading, discoloration, or degradation of the material due to exposure to UV rays. UV protection agents are used to preserve the pigments and overall appearance of the synthetic leather. Waterproofing agents can be incorporated into synthetic leather formulations to enhance the material's resistance to water absorption. These agents help repel water and prevent moisture penetration, increasing the material's durability and resistance to staining or damage caused by water exposure. Waterproofing agents can be added to the entire formulation or applied as a topcoat. Colorants and pigments are used to enhance the visual appearance of synthetic leather. They add colour and improve the aesthetic appeal, allowing manufacturers to produce synthetic leather in a wide range of styles and patterns to meet market demands. Incorporating pigments into the formulation, results in consistent coloration throughout the material. By applying a layer of pigment and additives to the surface, it provides the material with desired properties such as UV resistance, hydrophobicity, fire resistance, and more. Antioxidants are added to inhibit oxidation reactions, which can lead to discoloration, brittleness, and other forms of deterioration. Therefore, these agents help maintain the integrity and prolong the lifespan of synthetic leather products. Antimicrobial agents are used because synthetic leather can be susceptible to the growth of bacteria, fungi, and other microorganisms. Stated agents are added to prevent the growth of these microorganisms, reducing the risk of odours, stains, and deterioration caused by microbial activity. This is particularly important in applications where hygiene is a concern, such as medical equipment or upholstery in public spaces. Stabilizers are used to maintain the stability and structural integrity of the material, preventing it from becoming brittle, discoloured, or deteriorated. These agents improve the durability and resistance of synthetic leather to external conditions, ensuring it retains its desired characteristics for a longer period. Water purification system The water used in the process is potable water from the country's supply system (Prato, Florence, Italy). It was filtered to remove the solvents and reverse changes in pH levels, which result from its chemical treatment. Water can be purified by dissolving DMF in cold distilled water and separating the solid product by filtration. The water purification process in this invention results in less than 2 % annual water loss, greatly adding to the sustainability of the process. The ion exchange process is a common method, used for the water purification in this invention. It works by replacing the contaminants with a safer ionic substance. To ensure successful removal, both the exchanged substance and the contaminant must have the same electrical charge and be soluble in water. Water softening is an example of the ion exchange process, which aims to decrease the levels of magnesium and calcium in water. Additionally, ion exchange can be used to eliminate harmful metals from water. For the ion exchange process to take place, the necessary equipment should include a micro-porous exchange resin. This resin holds a solution that is loosely bound. When the process is used for water softening, sulfonated polystyrene beds are inserted into the unit. These beds are soaked with a sodium solution, forming a coating on the bed's surface. As water passes through the resin bed, the ions adhere to the beads, causing the release of the aforementioned solution into the water sample. Over time, the beds become saturated with contaminants, necessitating the regeneration or recharging of the exchange resin. To complete the regeneration process, it is crucial to use a salt brine solution that flushes the exchange resin. The salt brine solution comprises sodium ions that substitute the contaminants coating the resin bed, subsequently flushing out the contaminants with the waste water. The ion exchange process can be effectively utilized to address water softening needs in instances of hard water containing elevated levels of magnesium and calcium, along with its broader applications in general water treatment. Finishing Lamination Lamination is done via cold, hot-melt and UV lamination. For a textured finish, the material is warmed by hot cylinders which press on the material in order to create the texture, or warmed with a UV lamp depending on the type of polymer used. Lamination adheres a plastic film to the sheet of paper, while UV coating applies a liquid coat that is cured at 170 °C using ultraviolet light. Both can give the final material a glossy or matte finish. Laminated materials are much more durable than UV cured, making them suitable for products that will see long-term handling and wear like book covers. Pigmentation The material can be coloured in two ways: Firstly, by incorporating pigments into the formulation, resulting in consistent coloration throughout the material. The pigments are mixed into the formulation at the optimal temperature of 48 degrees Celsius. Secondly, by adding them to the formulation in the top coat, along with additives for desired properties such as UV resistance, hydrophobicity, fire resistance, and more. By introducing pigments through this method, a heightened vividity is achieved, as it is not mixed with barley powder. Moreover, in instances where the pigments do mix with barley powder, the latter constitutes merely 10 % of the top coat, primarily due to its impact on abrasion resistance. Consequently, even if the barley malt is present, it is in small amounts, so it does not significantly affect the visibility of the colours. Digital print Digital printing on synthetic leather refers to a modern printing technique that involves the application of digital ink directly onto the surface of synthetic leather material. It utilizes advanced digital printers equipped with specialized inkjet technology to create high-resolution and detailed prints on synthetic leather. In the digital printing process, a digital image or design is first created or selected using computer software. The image is then sent to the digital printer, which accurately reproduces the design onto the synthetic leather substrate. The printer sprays microscopic droplets of ink onto the material, forming the desired pattern, texture, or color. The finishing method in question offers several advantages for synthetic leather production. It allows for intricate and complex designs, including fine details and gradients, to be reproduced accurately. It offers versatility in terms of color choices and customization options. Furthermore, digital printing eliminates the need for traditional screen printing techniques, which can be more time-consuming and have limitations in design flexibility. Lifespan Based on targeted endurance, virgin PU has a longer life expectancy than bio based PU, which is useful for industries with fast changing trends- such as the fashion industry. For industries with a longer expected lifespan (10+ years) such as the automotive and home textiles, polycarbonate blends minimise waste and frequent replacement. Polyurethane (PU) is a polymer made from isocyanates and polyols, while polycarbonate is a polymer made from bisphenol A and phosgene monomers. Polyurethane is used for production of flexible foam, coatings and sealants because of its flexibility, low density and durability. Polycarbonate (PC) is used for construction purposes and production of impact discs because of its high impact resistance and ability to withstand high temperatures. Polycarbonate is one of the strongest polymers currently available for industrial use. Polyurethane’s inability to withstand temperatures higher than 93 °C is countered by polycarbonate’s properties, and polycarbonate’s low scratch resistance (average 118 in the Rockwell R scale) is countered by polyurethane’s durability, resulting in higher abrasion (>100.000 cycles). This invention refers to PC-PU blend to be the optimal polymer to be used in the textile industry as an alternative for traditional synthetic leather alternatives if durability is a desired property. Additionally, PC-PU has ideal properties for industries requiring high abrasion results, such as interior design and automobile industry. For example, it is stated in the article Designing High Performance Polyurethanes with PC-based PU Prepolymers (2023) that upon heating polycarbonate based polyurethanes in an oven at 120 °C for 50 days, the reduction in tensile strength is typically only 15-20 %. Moreover, immersion in water at 80 °C for 40 days causes a less than 10 % loss of tensile strength, whereas weathering in a climate chamber for 1200 hours leads to a 5 % decrease in strength. Furthermore, according to the article stated above, PC-PU are primarily used in the production of high-performance polyurethanes. The exceptional properties exhibited by PC-PU, in comparison to their traditional counterparts based on polyester or polyether, can be attributed to the incorporation of carbonate groups within the polymer structure. The carbonate group offers superior stability against hydrolysis and exhibits greater resistance to UV radiation and high temperatures, compared to the ether group. Consequently, polyurethane products containing polycarbonate moieties demonstrate exceptional durability against degradation agents such as hydrolysis, chemicals, thermal degradation, and UV radiation. For instance, these products remain relatively unchanged after soaking in water at 80°C for 3 to 4 weeks. In addition, PC-PU prepolymers offer numerous advantages in producing polycarbonate polyurethanes. They are easier to handle, exhibit storage stability, have better compatibility with other components, and result in a more uniform structure and improved polymer properties. Additionally, they provide a useful working pot life for various production procedures. Overall, utilizing PC-PU prepolymers enhances the efficiency and quality of PC-PU production. PC-PU prepolymers serve as the foundation for PU coatings that offer superior performance characteristics, including thermal stability, exceptional scratch and abrasion resistance, and superior gloss retention. Its technical characteristics are demonstrated in Table 4. Furthermore, they are highly resistant to water, chemicals and staining. Compared to polyurethanes based on polyether-diol or polyester-diol, PC-PU coatings demonstrate significant advantages - they experience over 85 % reduction in yellowing caused by weathering, over 50 % reduction in water absorption, nearly 90 % reduction in coating volume loss when subjected to harsh abrasion, and nearly 100 % gloss retention after heat ageing. Table 4. Technical characteristics of BSG-based leather made with PC- PU Tensile Max. elongation > 10 % ISO 1421 (along) Application of the method In the following non-limiting examples, BSG-based and DSG-based leather can be applied to the textile industry, fashion apparel, accessories, shoes, furniture, upholstery, luggage, in sports, for saddles and horsemanship etc. BSG-based leather finds diverse applications across various industries, catering to the growing demand for ethical and sustainable alternatives. In the fashion and apparel sector, it is a popular choice for creating clothing items like jackets, skirts, pants, and shoes, appealing to environmentally conscious consumers seeking cruelty-free options. The footwear industry extensively utilizes animal leather alternatives for producing sandals, boots, and sneakers, offering a comparable look and feel to traditional leather without using animal-derived materials. Moreover, BSG-based leather is harnessed to craft various accessories, including belts, wallets, handbags, backpacks, and purses, caused by demand from those seeking sustainable alternatives to animal leather products. In the field of interior design, BSG-based leather has use in various applications like wall coverings, lampshades, and decorative elements, as well as upholstery material for furniture like sofas, chairs, and cushions, providing an eco-friendly choice for furnishing homes and offices. The automotive industry also embraces this sustainable option, utilizing BSG-based leather to upholster car seats, steering wheels, and other interior components. Furthermore, BSG-based leather has applications in aviation and transportation sectors, where it is used for upholstering seats and interior components in a more environmentally friendly manner. The versatility of BSG-based leather extends to electronic device covers, protecting smartphones, tablets, and laptops with a sustainable alternative to synthetic or animal-derived materials. Additionally, it is utilized in bookbinding to create eco-friendly book covers, retaining the traditional look and feel of leather-bound books without using animal products. Even the medical and healthcare industries have begun exploring the potential of plant-based leather, employing BSG-based leather as an opportunity to be used for medical purposes such as orthopaedic supports or prosthetics, providing an ethical alternative to animal- derived materials in healthcare. Non-Patent citations Zeko-Pivač, A., Tišma M., Žnidaršič-Plazl, P., Kulisic, B., Sakellaris, G., Hao, J., Planinić, M. (2022) The Potential of Brewer’s Spent Grain in the Circular Bioeconomy: State of the Art and Future Perspectives. Frontiers in Bioengineering and Biotechnology, 10. doi: 10.3389 / fbioe.2022.870744 Mirum® plastic-free alternative to animal leather: Stella McCartney UK. MIRUM® Plastic-Free Alternative to Animal Leather. (2019) https: / / www.stellamccartney.com / ie / en / sustainability / mirum.html Key facts and findings. FAO. https: / / www.fao.org / news / story / en / item / 197623 / icode / Wang, S., Zhao, Q., Yu, H., Du, X., Zhang, T., Sun T., Song, W. (2023), Assessing the potential of Chlorella sp. phycoremediation liquid digestates from brewery wastes mixture integrated with bioproduct production. Front. Bioeng. Biotechnol. 11:1199472. doi: 10.3389 / fbioe.2023.1199472 Cimini, A., Moresi, M. (2016) Carbon footprint of a pale lager packed in different formats: assessment and sensitivity analysis based on transparent data. Journal of Cleaner Production, 112, 4196– 4213. doi:10.1016 / j.jclepro.2015.06.063 Duotank (2020) The carbon footprint of delivering beer to a bar [Whitepaper] Dishman, K. L. (2000) Sieving in Particle Size Analysis. Encyclopedia of Analytical Chemistry. doi:10.1002 / 9780470027318.a1514 Laus, A., Endres, F., Hutzler, M., Zarnkow, M., Jacob, F. (2022) Isothermal Mashing of Barley Malt: New Insights into Wort Composition and Enzyme Temperature Ranges. Food and Bioprocess Technology, 15(10), 2294–2312. doi: 10.1007 / s11947-022-02885-2 Designing High Performance Polyurethanes with PC-based PU Prepolymers. Polymer-Additives.specialchem.com. https: / / polymer- additives.specialchem.com / tech-library / article / designing-high- performance-polyurethanes-with-pc-based-pu-prepolymers

Claims

CLAIMS 1. Method for obtaining vegan leather alternatives comprising following steps: a) malting barley for alcohol productions; b) isothermal mashing; c) cooking; d) washing; e) filtration of the leftover husk; f) drying; g) milling; h) sieving; i) mixing; j) mixing organic solvent with the mixture obtained by step i); k) mixing the product obtained by step j) with dissolved polymer in the concentrations of dry polymer content of 20 -50%; l) pumping and uniformly spreading the product of the step k) and the remaining portion of organic solvent onto the textile; m) performing wet process for production comprising following steps: (i) applying adhesive layer to the product obtained from step l); (ii) application of polymer; (iii)planting the barley malt powder and polymer mixture obtained from step i) on the top layer; (iv) applying curing process; or performing dry process for production comprising following steps: (v) barley malt powder and polymer mixture obtained from step i) is heated until molten and then applied to the product obtained by step l); (vi) coated fabric obtained from step (v) is passed through a series of rollers which apply pressure and heat to activate the adhesive properties of the polymer and bond it;n) wet coagulation process or dry coagulation process and / or wet lamination process or dry lamination process; o) distillation; p) drying; q) coating with polymer layer; r) lamination finishing process; s) pigmentation; t) digital print.

2. Method according to claim 1 wherein the step f) is performed by dehydration or spray drying.

3. Method according to any of the preceding claims wherein the polymer used is selected from the group: polyurethane, rPU (recycled polyurethane), TPU (thermoplastic polyurethane), rTPU (recycled thermoplastic polyurethane) PC-PU (polycarbonate-polyurethane) , rPC-PU (recycled polycarbonate-polyurethane) PA (polyamide), rPA (recycled polyamide), PP (polypropylene), rPP (recycled polypropylene), PE (polyethylene) rPE (recycled polyethylene), PLA (polylactic acid), rPLA (recycled polylactic acid), PHA (polyhydroxyalkanoates), rPHA (recycled polyhydroxyalkanoates), PHBV (poly(3-hydroxybutyrate-co-3- hydroxyvalerate)), rPHBV (recycled poly(3-hydroxybutyrate-co-3- hydroxyvalerate)), bio-based polymers, vegetable oil-based polymers and natural and synthetic latexes.

4. Method to any of the preceding claims wherein step s) is cold-melt, hot-melt or UV lamination finishing process.

5. Vegan leather alternative obtainable by method according to any of the preceding claims.

6. Use of vegan leather alternative according to claim 5 in textile industry, fashion apparel industry, for making accessories, shoes, furniture, upholstery, luggage, sport items, saddles and horsemanship.

Images