Methods, systems, and reactors for producing 2g bioethanol

Abstract

The present disclosure refers to an ultrasonic baffled hydrothermal (UBH) reactor for lignocellulosic biomass pretreatment, which uses a rotating baffle (180) and blades (182) driven by an electric motor (73), around a heating coil (181) and an ultrasonic probe (177, 123). The present application also refers to the use of immobilized cellulase enzymes using metal organic frameworks (MOF). The present application also refers to a countercurrent saccharification process. The present application also refers to a thermosyphon that can be used in distillation coupled with a falling film. In addition, the present disclosure also refers to a process for the production of bioethanol using the UBH reactor, immobilized cellulase enzymes in a countercurrent process, and a falling film coupled with a thermosyphon. A system for the production of bioethanol is also presented, which comprises a UBH reactor, a countercurrent saccharification process, a falling film, and a thermosyphon. The use of a UBH reactor, enzymes, and a thermosyphon is also mentioned.

Description

Technical Field

[0001] This application relates to the energy and fuel sector, and more specifically, to improving the production levels and economic benefits of lignocellulosic 2G bioethanol. 2G bioethanol, or second-generation bioethanol, is a biofuel produced from non-food biomass, such as agricultural residues, forestry waste, or specialized energy crops (e.g., switchgrass). Unlike first-generation bioethanol derived from food crops such as sugarcane or corn, 2G bioethanol focuses on utilizing lignocellulosic materials—plant materials composed of cellulose, hemicellulose, and lignin.

[0002] This disclosure relates to a process and system for producing bioethanol by pretreating biomass using an ultrasonic baffled hydrothermal reactor.

[0003] This disclosure also relates to the encapsulation of enzymes and their production as part of the process.

[0004] This disclosure also relates to the use of a countercurrent saccharification system in the hydrolysis of pretreated biomass as part of the process.

[0005] This disclosure relates to a thermosiphon that can be coupled to a distiller for use in a distillation system that performs the process.

[0006] Reactors, enzymes, saccharification systems, and thermosiphons can be used to produce 2G of lignocellulose bioethanol. Background Technology

[0007] According to the OECD-FAO Agricultural Outlook 2020-2029, global bioethanol production is projected to grow from 122 billion liters (base period) to 143 billion liters by 2028. Notably, the leading biofuel producers are the United States, Brazil, Indonesia, Germany, China, Thailand, and Spain. Furthermore, the International Energy Agency (IEA) forecasts that biofuel production will reach 760 million tons of oil equivalent by 2050.

[0008] Before the COVID-19 pandemic, global bioethanol production was projected to reach 130 billion liters by 2024. Regulatory mandates for biofuels have been established in over 70 countries. For example, the Chinese government strongly supports non-food-based biofuels and second-generation ethanol plants. Indian regulators have mandated the construction of 12 second-generation ethanol plants. In the European Union (EU), the Renewable Energy Directive (RED) II sets targets for advanced biofuels and establishes a limit of 7% on the final energy consumption of traditional food-based biofuels, including bioethanol, in the road and rail transport sector by 2030.

[0009] In 2020, the European Commission updated its first action plan on the circular economy, which was launched in 2015. As part of the EU's Sustainable Growth Agenda, the revised Renewable Energy Directive (EU) 2018 / 2001 set a target of 3.5% for advanced biofuels in the transport sector. These biofuels must be produced from materials such as lignocellulosic biomass (bagasse, straw, or forestry waste).

[0010] Biofuel production from lignocellulosic biomass involves multiple steps, such as pretreatment, enzymatic saccharification, and microbial fermentation. A pretreatment step is essential for achieving efficient enzymatic saccharification of cellulose and thus, higher yields of fermentable sugars.

[0011] Pretreatment exposes cellulose by disrupting the lignocellulose matrix and makes it more reactive to cellulases [1]. During pretreatment, the complex polymer biomass structure is altered by breaking down the lignin barrier, removing lignin, and / or increasing its porosity. For practicality, pretreatment should meet the following requirements: low energy requirements and overall cost, efficient and rapid release of sugars in subsequent hydrolysis, reduced carbohydrate degradation, and avoidance of the formation of inhibitory compounds such as acids, furans, and phenols [2,3].

[0012] Due to the limited availability of non-renewable energy and the need to reduce CO2 emissions, the chemical industry is seeking more sustainable production routes to manufacture chemical compounds such as liquid fuels. Lignocellulosic biomass comprises cellulose (25-40%), hemicellulose (15-25%), and lignin (15-30%) as its main components. In the form of plant biomass, lignocellulosic biomass derived from any agricultural waste stream (such as grain straw and wood residues) is particularly suitable for conversion into biofuels due to its availability, low cost, and environmentally friendly production. Ethanol produced from non-food products or food waste, as well as other lignocellulosic biomass, is referred to as "second-generation ethanol."

[0013] The production of ethanol from cellulose is an important research topic worldwide. Producing ethanol from large quantities of inexpensive cellulose is a future trend. However, many key technological bottlenecks in this field remain unresolved.

[0014] Cao Lianying et al. pointed out in “Research Progress on Lignocellulosic Ethanol Key Technologies” that the cost of producing cellulosic ethanol based on lignocellulosic biomass is still very high. Instead, the main reason for this problem lies in the limitations of the following three key technologies: (1) efficient straw pretreatment technology; (2) low-cost industrial cellulase production technology; (3) optimization of mixed sugar ethanol fermentation technology [5].

[0015] Many established pilot or production lines, especially those in China, are currently in a dormant state. This is because, from the perspective of local technology, there are major problems such as incomplete cellulose purification, high waste mash pollution load, and difficulties in treatment.

[0016] Overall, the production of 2G bioethanol from lignocellulosic resources faces major limitations. These two limiting factors include low production efficiency and high production costs.

[0017] Developing sustainable and pollution-free energy is a technological trend. Agricultural production generates large quantities of lignocellulosic waste annually, such as straw and corn cobs. The main components of lignocellulosic materials are cellulose, hemicellulose, lignin, and a small amount of ash. While glucose can be obtained by enzymatically hydrolyzing and saccharifying cellulose components with cellulase, cellulosic ethanol can be produced through bio-fermentation of glucose. Cellulosic ethanol is considered a clean fuel.

[0018] As a novel biomass energy source, cellulosic ethanol possesses dual characteristics such as being renewable and environmentally friendly, and is the only renewable energy source that can be stored and transported. Currently, developed countries in Europe and the United States, as well as developing countries such as Brazil, have widely adopted cellulosic ethanol as fuel.

[0019] In combined pretreatment, biomass components are typically recovered separately in different feed streams. Compared to single technologies, combined pretreatment appears to increase process efficiency; they allow for higher sugar yields under milder operating conditions and require lower solvent and enzyme dosages, thus improving the cost and sustainability of the final product. Currently, combined methods such as ultrasound-assisted techniques and hydrothermal and alkaline processes have been proposed.

[0020] The most crucial step in the production of lignocellulose-based bioethanol is the conversion of cellulose and hemicellulose into soluble sugars. Recently, the enzymatic hydrolysis of cellulose has received considerable attention. In enzymatic hydrolysis, cellulase performs the hydrolysis of cellulose and hemicellulose into sugars. Besides bioethanol, the glucose obtained from the hydrolysis step can be converted into a variety of high-value-added chemicals.

[0021] Cellulose hydrolysis is a fundamental and costly step in the production of 2G bioethanol from lignocellulose, as the stability of cellulase requires challenging and demanding conditions in industrial processes. Therefore, cellulase recovery is a crucial process for creating sustainable and cost-effective 2G bioethanol production. On the other hand, the demand for cellulase in the hydrolysis step is even greater due to the various inhibitors generated during pretreatment, such as weak acids, furan derivatives, and phenols. Therefore, finding ways to protect cellulase from these inhibitors, eliminating the large number of separation and washing steps rich in cellulose solids from the pretreatment stage, and using the entire pulp from the pretreatment as a substrate in the enzymatic hydrolysis stage is attractive and considered economical.

[0022] To address the aforementioned drawbacks of free enzymes, numerous methods have been employed, including immobilization, artificial modification, protein and enzyme engineering, solvent engineering, and directed evolution of enzymes.

[0023] An important method for the protection and recovery of cellulase is to immobilize it on a substrate as a protective agent against environmental impacts. Cellulase immobilization is a powerful and convenient tool for addressing the challenges of using it as an industrial catalyst. Fortunately, in lignocellulosic biomass hydrolysis processes, immobilized cellulase exhibits properties similar to, and sometimes even superior to, free cellulase (e.g., in the presence of organic solvents).

[0024] In this disclosure, we attempt to significantly improve the economic and technical efficiency of the lignocellulose 2G bioethanol production process by focusing on two main limiting factors and creating the systems and reactors for implementing this process. Summary of the Invention

[0025] The task of this application

[0026] The objective of this application is to create an improved process and system for producing 2G bioethanol, which offers higher efficiency, lower cost, and greater process stability by mitigating the drawbacks of conventional processes. Furthermore, the objective of this application is to create an advanced reactor for producing 2G bioethanol based on the proposed process and system.

[0027] Therefore, the overall objective of this application is to increase output and economic benefits, and to reduce the disadvantages of conventional processes.

[0028] The first aspect of this disclosure is to provide an ultrasonic baffled hydrothermal (UBH) reactor for the pretreatment of lignocellulosic biomass.

[0029] The second aspect of this disclosure is to provide an immobilized enzyme using a metal-organic framework in a countercurrent saccharification system.

[0030] The third aspect of this application is to provide a method for producing enzyme complexes.

[0031] The fourth aspect of this disclosure is to provide a thermosiphon for use in distillation processes.

[0032] The fifth aspect of this disclosure provides a distillation system.

[0033] The sixth aspect of this disclosure is to provide a process for producing 2G of bioethanol.

[0034] The seventh aspect of this disclosure is to provide a system for producing 2G bioethanol, the system comprising a UBH reactor, a countercurrent saccharification process, a falling film reactor, and a thermosiphon.

[0035] The eighth aspect of this disclosure is the use of the UBH reactor.

[0036] The ninth aspect of this disclosure is the use of a thermosiphon.

[0037] The tenth aspect of this disclosure is a countercurrent saccharification process using cellulase@MOF (metal-organic framework cellulase complex).

[0038] In view of this, this disclosure aims to improve the production process of lignocellulose 2G bioethanol by creating methods and systems for pretreatment, hydrolysis, and distillation steps. Furthermore, it reduces production costs, including those associated with enzymatic hydrolysis, pretreatment, and fermentation processes. In the pretreatment stage, a three-part reactor with an ultrasonic homogenizer is used to improve delignification efficiency. In the hydrolysis stage, a series of operations, including the production of consumable enzymes and the use of cellulase@MOF in countercurrent saccharification technology, will significantly reduce enzyme-related costs. The distillation step also reduces energy consumption by using a falling film cooling system improved by a thermosiphon cooler.

[0039] This application overview

[0040] The purpose of this application is achieved by a process for producing 2G bioethanol including the steps of claim 1, by the system of claim 9, and by an ultrasonic baffled hydrothermal (UBH) reactor for biomass pretreatment including the technical features of claim 10 as a key part of the process, and also by the thermosiphon cooling system of claim 16 and the countercurrent hydrolysis reactor of claim 18, all parts of the system. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the UBH reactor as seen from the outside.

[0042] Figure 2 This is an open diagonal schematic diagram of the UBH reactor, showing the interior of the reactor with baffles, ultrasonic probes, and heat sinks.

[0043] Figure 3 This is a top view of the interior of the UBH reactor, which includes baffles, ultrasonic probes, and heat sinks.

[0044] Figure 4 A first embodiment of a system for producing 2G of bioethanol is shown, which has all the equipment and process steps for producing 2G of bioethanol.

[0045] Figure 5 A falling film coupled with a thermosiphon is shown.

[0046] Figure 6 A diagonal view of the falling film coupled to the thermosiphon is shown.

[0047] Figure 7A , Figure 7B and Figure 7C Details of the thermosiphon are shown.

[0048] Figure 8 A distillation system with molecular sieves is shown.

[0049] Figure 9 The spectrum showing the effect of the baffle plate on lignin content is displayed.

[0050] Figure 10 The spectrum shows the effects of ultrasound and temperature on lignin content.

[0051] Figure 11 The FTIR peaks corresponding to the functional groups of the lignocellulose components according to Table 5 are shown.

[0052] Figure 12 The FTIR spectrum of the baffle effect test is shown.

[0053] Figure 13 FTIR spectra represent different combinations of ultrasound, baffles, and temperature.

[0054] Figure 14 Including scanning electron microscopy analysis of untreated rice straw.

[0055] Figure 15 Scanning electron microscopy analysis of rice straw treated with baffles (top), baffles of the present disclosure (middle), and conventional baffles (bottom).

[0056] Figure 16Scanning electron microscopy analysis of rice straw treated at 80℃ (top left), 80℃ + ultrasound (top right), 100℃ (middle left), 100℃ + ultrasound (middle right), 120℃ (bottom left), and 120℃ + ultrasound (bottom right).

[0057] Figure 17 A three-dimensional schematic diagram of the CCH system is shown.

[0058] Figure 18 Including scanning electron microscopy analysis of MAF-7.

[0059] Figure 19 Scanning electron microscopy analysis of cellulase@MAF-7 was included.

[0060] Figure 20 Images including the XRD patterns of MAF-7.

[0061] Figure 21 Images including the XRD pattern of cellulase@MAF-7. Detailed Implementation

[0062] Ultrasonic-assisted hydrothermal pretreatment is used in 2G bioethanol production to improve the efficiency of biomass conversion into biofuels. Furthermore, since no hazardous or toxic chemical reagents are used, it can be considered a green alternative to traditional pretreatment methods.

[0063] When hydrothermal processes are combined with ultrasound, the required energy input is lower. Consequently, the pretreatment process is enhanced to be more environmentally friendly because ultrasound breaks down the lignocellulosic matrix, making the biomass easier to process.

[0064] In view of this, protection is required such as Figures 1 to 3 The ultrasonic baffled hydrothermal (UBH) reactor is shown. This disclosure mentions a UBH reactor for biomass pretreatment, wherein the UBH reactor comprises:

[0065] The reactor body 172 is coupled to the flange-type top cover 176;

[0066] The flanged top cover 176 includes multiple inlets 66 for attachment:

[0067] -External heating / cooling inlet;

[0068] - Shaft 175 aligned with the center of the flanged top cover; and

[0069] - Multiple ultrasound probes 123;

[0070] The reactor body 172 includes:

[0071] a. Inlet 66, for untreated materials;

[0072] b. Bottom section, with an outlet 174 for reactor products;

[0073] c. Multiple heating / cooling coils 181 are located inside the reactor body;

[0074] d. Air pressure inlet / outlet, located on the top outer side of reactor body 172;

[0075] e. A stirring shaft 175, located inside the reactor body 172, is connected to a motor 73 and includes:

[0076] - The stirring system is located at the bottom of the stirring shaft 175;

[0077] - A 180° curved baffle plate is positioned above the stirring system;

[0078] The curved baffle 180 is configured to prevent swirling / eddy currents of the material in the reactor and to improve the mixing rate.

[0079] In this disclosure, the UBH reactor is composed of cylindrical and quasi-spherical sections, preferably wherein the top cover and bottom are quasi-spherical, and the middle part of the reactor is cylindrical. The reactor shaft 175 is also cylindrical and has an internal space that allows the stirring shaft 175 to rotate freely.

[0080] In this disclosure, the reactor includes 2 to 5 ultrasonic retainers 177, preferably three ultrasonic retainers 177 that are symmetrically distributed at equal intervals.

[0081] In this disclosure, the number of ultrasonic retainers 177 is proportional to the number of baffles 180. Viewed from above, the probe 123 must be positioned in the middle of the baffle 180.

[0082] Each ultrasonic retainer 177 includes at least one flange. Additionally, the feed inlet 66 and the top cover include flanges. Each flange includes approximately 8 to approximately 16 equally spaced bolts; preferably, the flange of the ultrasonic retainer 177 includes 8 bolts, the flange of the feed inlet includes 12 bolts, and the flange of the top cover includes 16 bolts. The ports of the reactor body 172 and the top cover are airtightly flange-sealed via the flanges of the ultrasonic retainers 177.

[0083] In addition, the number of bolts on a flange depends on availability and desired sealing, so the number of bolts can be changed, but must conform to specifications. For example, if the top cover flange is to be replaced, it must still be airtight.

[0084] The ultrasonic probe 123 in the reactor reduces inhibitor production by lowering the pretreatment temperature. Because ultrasound disrupts the lignocellulose matrix, making the biomass more manageable, it requires less energy input. Ultrasound increases access to the porous structure by creating microbubbles.

[0085] In addition, the top cover of the ultrasonic hydrothermal reactor includes two identical or different inlets 66, preferably identical.

[0086] In this disclosure, the heating / cooling coil 181 is wound around the reactor about 5 to about 20 turns, preferably about 10 to about 15 turns, more preferably 13 turns, and has an inlet and an outlet for steam. The selected number of turns achieves maximum heating surface.

[0087] The UBH reactor also includes a shell. This shell includes a heating jacket with an inlet and outlet 183 for oil, so that the internal temperature of the reactor can be controlled by raising or lowering the temperature if necessary.

[0088] The housing also includes at least two base arms or legs for lifting. Typically, it includes about two to about six legs and / or arms, preferably about four legs and / or arms.

[0089] For the purposes of this disclosure, the stirring system includes heat sinks having about 2 to about 6 blades 182, preferably having 4 blades 182. The heat sinks may be diagonally arranged.

[0090] In this disclosure, the UBH reactor includes approximately 3 to approximately 5 baffles 180, preferably 3 baffles 180, wherein the curved baffles 180 include holes located in each curved baffle. Since the baffles 180 do not allow turbulence and eddies in the system, free movement caused by the agitation of the lignocellulose component is achieved. The holes are circular in shape and related to the free movement of the lignocellulose component in the reactor; therefore, these baffles 180 prevent turbulence in the system while also allowing free movement of this component. The baffles 180 are equidistantly distributed, and each baffle 180 has approximately 5 to approximately 10 holes in the horizontal direction, the number of holes in the horizontal direction being directly related to the width of the baffle 180. Each baffle 180 also has approximately 15 to 25 holes in the vertical direction, the number of holes in the vertical direction being directly related to the length of the baffle 180.

[0091] In addition to preventing swirling / eddy currents of the material in the reactor (which occur together with thorough mixing in the three sections of the reactor), the baffle 180 of this disclosure also improves the efficiency of the mixing rate and reduces the operating time.

[0092] The UBH reactor disclosed herein can be used in a wide range of plants, such as petrochemical plants, biofuel plants, and other lignocellulose processes.

[0093] This disclosure also relates to cellulases immobilized with metal-organic frameworks (MOFs) for use in cellulose hydrolysis.

[0094] The cellulase fixed in this disclosure is a permeable or encapsulated cellulase, preferably an encapsulated cellulase.

[0095] In addition, in this disclosure, MOF is selected from the group including ZIF-7 (Zn), MOF-199 (Cu) and MAF-7 (Zn).

[0096] One of the most important steps in the production of 2G bioethanol is the hydrolysis / saccharification step. In enzymatic hydrolysis, cellulases perform the hydrolysis of cellulose and hemicellulose into sugars. Cellulase is a term used for a group of enzymes that includes endopeptidase β-1,4-glucanase (EG), cellobiose hydrolase (CBH), and β-glucosidase (β-G). Of these three groups of enzymes, EG and CBH convert cellulose to cellobiose, and then β-G converts cellobiose to glucose.

[0097] Metal-organic frameworks (MOFs) are hybrid porous materials. More specifically, these hybrid porous materials comprise crystalline structures composed of inorganic metals as nodes and organic compounds as linkers. MOFs can be used to effectively immobilize and protect enzymes. Due to their unique properties, such as high porosity (due to the lack of walls in the scaffold-like structure), high surface area, and good temperature stability, these structures have diverse applications, such as gas absorption, sensors, and heterogeneous catalysts. Similarly, these properties of MOFs provide thermal and chemical protection for enzymes and result in excellent adsorption capacity.

[0098] Immobilizing cellulase using MOFs can be achieved through precipitation methods and encapsulation within MOF pores. However, due to the microporous structure of MOFs, cellulase is often only immobilized on its outer surface, and its porosity is not effectively utilized. Nevertheless, "in-situ encapsulation" is an acceptable method for placing cellulase inside the MOF pore cavity because it significantly improves cellulase loading and binding, thereby minimizing leaching and waste during processing.

[0099] In addition, placing cellulase inside the pores of MOFs induces favorable structural defects in the framework backbone, thereby increasing the average pore size and improving the cellulose hydrolysis process. Generally, water-stable MOFs can withstand high temperatures and extreme pH conditions (high and low pH), which is desirable for saccharification processes. MOFs used in various studies on cellulase immobilization and cellulose hydrolysis include ZIF-8 (Zn), UiO-66-NH2 (Zr), MIL-100 (Fe), MIL-127 (Fe), Zn-mIm, Cu (PABA), Zr (MP-UIO-66), ZIF-8 hybrid membrane, UIO-66-Zr, zinc-based MOF (Zn-mlm), Uio-66-NH2, MAF-90, MIL-101 (Cr), MIL-53 (Al), and MOF-199 (Cu).

[0100] The mesoporous Zr-based MOF (MP-UIO-66) has been used to immobilize cellulase, and studies have shown that the affinity and catalytic efficiency of the substrate to the catalyst are higher than those of the substrate to free cellulase.

[0101] UIO-66-Zr has been used to stabilize cellulase, and it has been observed that the enzyme activity can still be maintained at 80% after 6 cycles.

[0102] Cellulase was immobilized on a ZIF-8 hybrid membrane. Compared to free cellulase, the immobilized enzymes maintained their activity at high temperatures and high pH values.

[0103] Zinc-based mesoporous MOFs (Zn-mlm) have been used to stabilize cellulase. Cellulase@Zn-mlm maintains up to 65% of its enzyme activity at pH 8, compared to only 10% for free cellulase. Furthermore, after four cycles, the enzyme activity is retained at 77%.

[0104] Cellulase was stabilized on a Uio-66-NH2 magnetic core-shell. This system can be continuously recovered for up to 5 cycles. A catalyst was produced by immobilizing cellulase on Uio-66-NH2, and the catalyst exhibits high heat resistance and high pH resistance. In this study, 85% of the enzyme activity was retained at 80 °C. Moreover, after 10 cycles, 75% of the initial activity was retained.

[0105] MAF-7 has been used in catalytic systems to stabilize magnetic nanoparticles and lactate dehydrogenase (LDH). This system exhibits better tolerance to acids, bases, temperatures and strong solvents [4]. Studies have shown that the enzyme activity of catalase or urease stabilized by the hydrophilic MAF-90 and MAF-7 is retained under harsh environmental conditions (high temperature, denaturants or proteolytic agents, etc.), while ZIF-8 does not provide tolerance [5].

[0106] Besides their crystallinity, porosity, and active sites, MOFs are also referred to as "enzyme-like" materials because their structures are similar to those found in natural metalloproteinases. Therefore, MOFs are ideal catalysts for biochemical reactions such as cellulose hydrolysis.

[0107] The metal nodes and organic linkers in MOFs can be synthesized during synthesis or during post-synthetic modification, modified with functional groups (such as sulfonic acids, amines, amides, etc. as acid-base centers) and metals (as redox sites), and provide a special environment for the hydrolysis of cellulose biomass. It should be noted that most common MOFs, such as MOF-5 and MOF-199, are manufactured on an industrial scale by various companies, including BASF.

[0108] Compared to free cellulase, immobilized cellulase exhibits better tolerance to formic acid and vanillin (two typical inhibitors found in lignocellulose pre-hydrolysates). To make lignocellulose biorefining more economically feasible, it is necessary to recover and reuse cellulase after hydrolysis. Therefore, immobilization is an effective and convenient tool to address the problems associated with using enzymes as industrial catalysts, namely enzyme recyclability, enzyme stability, enzyme selectivity, and reducing the inhibitory effects of compounds present in the reaction medium.

[0109] MOF materials possess the advantages of high porosity and high specific surface area, leading to their widespread application, especially in enzyme immobilization. MOFs offer a high surface area and large pore volume, facilitating the transport of enzyme substrates through porous networks. Compared to other traditional porous materials (such as mesoporous metal oxides and silica), they also provide excellent thermal and chemical protection for enzymes.

[0110] The metal ions that form MOF materials can be selected based on their low cost, low toxicity, and, of course, their potential to form MOFs in water at room temperature, in order to achieve a closed loop of economic, environmental, and energy sustainability throughout the synthesis, application, and disposal lifecycle.

[0111] Enzymes are relatively unstable, especially their tertiary structures that give them their biocatalytic properties. Even limited changes in temperature or acidity, the presence of foreign chemicals in the medium, or, of course, the use of non-aqueous solvents, can lead to enzyme inactivation. Therefore, one-pot immobilization of enzymes means that the carrier must be able to form in the presence of the enzyme without altering its structure / activity.

[0112] The method, known as "biomimetic mineralization," is carried out in the absence of a capping agent. In this approach, enzymes induce MOFs to grow in water, ultimately embedding the enzyme within the MOF crystals. Table 1 shows an overall comparison of enzyme immobilization methods using MOFs.

[0113] Table 1 - Comparison of Enzyme Immobilization Methods

[0114]

[0115] This disclosure also relates to a method for synthesizing cellulase@MOF. This method is carried out via the following general route:

[0116] a) Prepare an aqueous solution of the metal salt; simultaneously prepare a citrate buffer solution of 2 mg cellulase / mL and 50% by weight of polyvinylpyrrolidone;

[0117] b) Preparation of aqueous solutions of organic ligands;

[0118] c) Add solution (a) slowly and dropwise to the stirred solution (b) at room temperature;

[0119] d) After approximately 6 to approximately 12 hours, centrifuge and wash the structure;

[0120] e) Finally, dry and store the structure.

[0121] In this disclosure, the structure is dried by a freeze dryer and stored in a refrigerator at a temperature of about 0°C to about 6°C, preferably about 2°C to about 5°C, and most preferably about 4°C.

[0122] Enzymes can be obtained from different companies. However, it is also possible to produce enzymes using fungal species.

[0123] Overall, enzyme costs account for a significant portion of the cost of lignocellulose-based 2G bioethanol production processes. In this disclosure, in addition to producing the enzyme within the system itself and using MOFs to recover and stabilize the enzyme, a countercurrent saccharification method has been used as the basic system in the enzymatic hydrolysis step, reducing enzyme consumption by more than 15 times compared to other commonly used methods. This characteristic is well known to significantly reduce the production cost of lignocellulose-based 2G bioethanol. Furthermore, by placing the cellulase within an MOF, it can be protected from environmental impacts.

[0124] Cellulase@MOF is used in hydrolysis / saccharification processes. More precisely, it can be used in conjunction with a countercurrent system (CCH) to convert cellulose into sugars such as glucose.

[0125] This disclosure relates to a thermosiphon heat pipe condenser 103, wherein the thermosiphon includes:

[0126] - Upper chamber 102 and lower chamber 102, the top chamber includes:

[0127] - Top wall, bottom wall, and two side walls;

[0128] - Multiple fans 161 installed on the top wall;

[0129] - A plurality of refrigerant pipes 160 located inside the upper chamber and attached to the side walls of the two upper chambers, the refrigerant pipes 160 passing through the bottom wall of the upper chamber 102 and entering the bottom chamber 102 through the top wall of the bottom chamber;

[0130] -The bottom chamber includes:

[0131] - Top wall, bottom wall, and two side walls;

[0132] - Inlet 159 for steam;

[0133] - For liquid outlet 163;

[0134] - A pipe with multiple spirals connecting the inlet and outlet;

[0135] - Refrigerant pipe 160 attached to the side wall of the bottom chamber.

[0136] The thermosiphon disclosed herein is a passive cooling system that relies on gravity and density to circulate the refrigerant fluid, rather than on a capillary wick structure. The advantages of this device include its compact design, water conservation, and ability to operate for extended periods without external power.

[0137] In one embodiment, the bottom wall of the upper chamber is connected to, or is the same as, the top wall of the bottom chamber. In another embodiment, an open space exists between the upper and bottom chambers, in which the refrigerant piping is in contact with air.

[0138] Typically, a thermosiphon is used to preheat the still (e.g., a falling film still). However, in this disclosure, the thermosiphon is used as a condenser and is responsible for cooling the still.

[0139] For the distillation of viscous fluids and slurries, falling film distillation columns are an effective choice. This process is simple and similar to conventional distillation columns, but with some differences. For example, hot steam is used to heat the feed instead of a boiler at the bottom of the column. This disclosure also mentions distillation systems, which include:

[0140] - Falling film evaporator 154 has an inlet 155 for low concentration ethanol, a top outlet 105 and a bottom outlet 157, wherein the bottom outlet 157 transmits residue and the top outlet transmits 2g of gaseous bioethanol.

[0141] -Thermosiphon 103, configured to convert gaseous ethanol into liquid ethanol and cool the evaporator;

[0142] - Optional additional purifier to improve product purity.

[0143] Figure 5 An embodiment of a distillation system is shown, the distillation system comprising:

[0144] - Falling film evaporator, which includes:

[0145] -Feed inlet 155;

[0146] -Hot steam inlet 106;

[0147] - Falling film tower shell 154;

[0148] - Steam outlet 105;

[0149] - Residue / slurry outlet 157;

[0150] - Separate water particles from steam 158;

[0151] - A thermosiphon condenser 103 with a distillate output of 163.

[0152] Optionally, such as Figure 8 As shown, it may also include:

[0153] - Purification of fluidized beds, including:

[0154] - The molecular sieve 164 recovery unit is designed to operate in a vacuum environment;

[0155] - Molecular sieve 164, which includes a silica gel bath and is designed to operate under pressure.

[0156] The distillation system disclosed herein can be used in a variety of plants, such as petrochemical plants, biofuel plants (such as 2G bioethanol), and other processes that require a distillation step.

[0157] This disclosure also relates to a process for producing 2G of bioethanol, wherein the process includes the following steps:

[0158] I. Obtaining raw materials;

[0159] II. Physical pretreatment of raw materials;

[0160] III. The material leaving step I is subjected to hydrothermal pretreatment to form a mixture of lignin, cellulose and hemicellulose;

[0161] IV. In the presence of an enzyme solution, cellulose and hemicellulose are converted into sugars;

[0162] V. Ferment sugars into diluted crude ethanol.

[0163] VI. Distilling crude ethanol; and

[0164] VII. Obtain 2G of bioethanol product.

[0165] For the purposes of this disclosure, step III, hydrothermal pretreatment of the material, includes converting the material in an ultrasonic baffled hydrothermal (UBH) reactor as previously described.

[0166] The following paragraphs describe the steps of the process.

[0167] Step I – Obtaining Raw Materials

[0168] For the purposes of this disclosure, raw materials and biomass have similar meanings. Among possible raw materials, agricultural and forestry waste includes, but is not limited to, bagasse, wheat straw, rice straw, corn stalks, forestry residues, fruit and vegetable waste, and similar wastes containing abundant biomass energy.

[0169] Step II – Physical Treatment

[0170] In this disclosure, step II begins with the transfer of raw materials. Given the raw materials and their need for crushing, storage, or drying, a combination of different machines may be used.

[0171] In one possible embodiment, step II includes the following sub-steps:

[0172] A' – Drying raw materials to produce dried straw;

[0173] B' – Storing dry materials in silos; and

[0174] C' – Using an extruder to crush and compress dry materials.

[0175] In the storage silo of sub-step B', the raw materials are compressed and then stored under optimal environmental conditions to protect them from spoilage over a longer period. Sub-step A' can be performed in a rotary dryer, vertical dryer, or open-air conditions.

[0176] In this embodiment, the compressed straw is crushed into small particles by an extruder before entering the main pretreatment reactor to increase the available surface area and thus improve process efficiency.

[0177] In this disclosure, Embodiments II A'-B'-C' are preferred embodiments.

[0178] Step III – Hydrothermal Treatment

[0179] During step III, cellulose and wet lignin are further separated, and the black liquor containing lignin enters its own area for lignin separation, where it can be dehumidified in a decanter, while the remaining solids containing cellulose and cellulose enter step IV.

[0180] Different treatments have different advantages and disadvantages. Therefore, using a combined approach helps to create complementarity between different methods. To this end, a hydrothermal reactor combining alkaline and ultrasonic methods is proposed.

[0181] The material enters UBH reactor 172. In this reactor, the material is exposed to hydrothermal conditions and ultrasound. Moreover, the partitioning of the reactor's internal space facilitates the transport of the energy and heat required for ultrasound generation.

[0182] In this process, after the biomass / raw material is treated in step I, it is introduced into the UBH reactor 172. In this reactor, the mixture is exposed to critical hot water at temperatures up to about 150°C, preferably about 120°C to about 145°C, and most preferably about 130°C to about 140°C. These temperatures can enhance the process but reduce the damage to the cellulose structure. Conventional methods use 170°C to 180°C, thus less damage to the cellulose structure has been observed in this process.

[0183] The applied pressure was also as high as approximately 13.6 atm (1.27 × 10⁻⁶). 7 Pa), preferably about 7 atm (7.1 × 10 Pa). 5 Pa) to approximately 12 atm (1.2 × 10⁻⁶ Pa) 6Pa), most preferably about 9 atm (9.1 × 10 Pa). 5 Pa) to approximately 10 atm (1×10 6 Pa).

[0184] In this disclosure, the pressure and temperature of steam / water break down the biomass structure and make it more readily available for subsequent enzymatic conversion.

[0185] Furthermore, because of the high pressure and high temperature used, the UBH reactor 172 must be airtight, therefore it must be operated in batches. The operation time is at least approximately 30 minutes.

[0186] Because the alkali content is lower than that of conventional alkaline pretreatment (approximately 0.01M to approximately 0.1M), the lignocellulose structure, such as hemicellulose and cellulose, suffers less damage, but the lignin removal rate is higher than that of liquid hot water (LHW) pretreatment without NaOH. NaOH also prevents the formation of acid inhibitors (furfural, hydroxymethylfurfural (HMF), and acids) and improves the accessibility of carbon structures in the enzymatic hydrolysis step while reacting with hemicellulose acetate.

[0187] To avoid acidification of the reaction conditions due to high temperatures, we use a NaOH solution. The consumption of this solution is solely to maintain the reaction medium at a neutral pH. Therefore, compared to hydrothermal methods, fewer inhibitors are generated, and compared to traditional chemical methods, fewer chemicals are used.

[0188] The ultrasonic probe 123 also reduces inhibitor production by lowering the pretreatment temperature. Because ultrasound breaks down the lignocellulose matrix, making the biomass easier to process, it requires less energy input.

[0189] Furthermore, ultrasound enhances access to the porous structure by creating microbubbles and improves the efficiency of enzymatic hydrolysis, thus compensating for the efficiency reduction caused by the temperature limitations imposed by the reactor. Ultrasound is generated by a stirrer inside the reactor body. Baffles divide the internal space of the reactor, allowing the ultrasonic energy to interact optimally with the substrate to a greater extent.

[0190] The reactor baffle 180 improves fluid distribution while enhancing heat transport. The baffle described in this disclosure prevents eddies and increases the mixing rate.

[0191] It should be noted that by using vacuum recovery methods, the consumption of chemicals, water, and total energy can be reduced to the desired level. Furthermore, using a single reactor reduces overall construction and maintenance costs.

[0192] In such Figure 4In one embodiment of this application, the hydrothermally pretreated product is separated by a centrifuge, and simultaneously, cellulose and hemicellulose are transferred to step IV, while wet lignin is decanted and can be used for other products (step VII).

[0193] Lignin can also be recovered from black liquor through precipitation, that is, by lowering the pH with CO2, dewatering using a filter press, and redissolving it in water and acid. The pulp is then dewatered and washed again to produce a high-purity lignin stream.

[0194] Lignin is one of the most important byproducts of the 2G bioethanol production process. It can be used to produce a wide variety of products across various industries, including bibbers, phenolic compounds, activated carbon, fuels, and bioplastics.

[0195] Water discharged from the dehydration tank is returned to the pretreatment reactor to save water consumption.

[0196] Step IV – Hydrolysis / Saccharification

[0197] In step IV, cellulose and hemicellulose are converted into glucose and xylose via saccharification. The saccharification of step IV is performed in about 3 to about 8, preferably about 3 to about 5, saccharification countercurrent reactors, using a commercially available or manufactured cellulase. The enzyme may be a metal-organic framework-cellulase complex (cellulase@MOF). For this application, the enzyme is preferably an encapsulated enzyme as previously described.

[0198] At this step, the countercurrent saccharification (CCH) method, aided by encapsulated vitaminase or permeable cellulase catalysts, is considered to improve the hydrolysis efficiency of cellulose and hemicellulose and reduce operation time.

[0199] Traditionally, enzymatic saccharification is performed using a batch process, with a typical reaction time of approximately 3 to 7 days. At the end of batch saccharification, the enzyme activity is retained, but the remaining enzyme is usually discarded. To reduce enzyme costs by reusing the remaining enzyme, a countercurrent process was developed.

[0200] For chemical processes, countercurrent systems are generally more efficient than batch systems and offer advantages such as more efficient substrate utilization, continuous processing that avoids downtime during loading and unloading, and lower product inhibition.

[0201] In a countercurrent saccharification (CCH) system, biomass and liquid flows enter the system in opposite directions. Fresh biomass encounters the product liquid at one end, while degraded biomass encounters fresh liquid at the other end. The sites of enzyme (especially β-glucosidase) addition are carefully selected to maximize enzyme utilization. Enzymes present in the product liquid are utilized by the fresh, active biomass at one end, thus reducing the impact of product inhibition. At the other end, the degraded biomass is washed with fresh liquid to recover inactive enzymes and product sugars, thereby improving process efficiency. Because the liquid product is the last to contact fresh, highly active biomass, it can potentially achieve high sugar concentrations.

[0202] Optimal operation was achieved through the efficient use of enzymes, allowing for a reduction in enzyme load of approximately 8 to approximately 20 times compared to conventional methods.

[0203] Such as Figure 17 What we see here is not a single reactor used for hydrolysis, but a continuous system using multiple connected reactors. Solids from the pretreatment step enter from one side of this system 145 (the first reactor) along with the cellulase@MOF catalyst, and the enzyme solution enters from the other side of the system 231 (the last reactor).

[0204] In this innovation, metal-organic frameworks (MOFs) function in two stages: first, by mixing with the fresh biomass entering the system; and second, by residing in the final container. The MOFs mixed with the biomass act as a buffer against the inhibitory effects of glucose and lignin on the enzyme, moving with the biomass along the entire pathway and continuing saccharification even at high sugar concentrations. The MOFs in the final container also contribute to the complete conversion of cellobiose to glucose, and because they are recyclable, they significantly reduce enzyme consumption. This innovation marks the first use of hydrophilic metal-organic framework MOFs to stabilize cellulase. Studies have shown that the enzymatic activity of this catalyst is comparable to that of the free enzyme, while unlike the free enzyme, the system is reusable.

[0205] In summary, this application provides a complete system for the saccharification of lignocellulosic biomass. This system comprises multiple reactors arranged sequentially in rows. The first reactor forms a countercurrent saccharification (CCH) system, and the last reactor 147 is associated with a cellulase@MOF system. Freshly pretreated biomass, along with a small amount of cellulase@MOF, enters the penultimate reactor, where it encounters a sugar-rich solution. Consequently, its cellulose and hemicellulose compounds are hydrolyzed by soluble enzymes and enzymes stabilized in the cellulase@MOF, producing reducing sugars. The solid biomass, along with the cellulase@MOF mixed with it, then separates from the enzyme solution and enters the preceding reactor, from where it moves countercurrently along the system with the enzyme solution until it finally enters the first reactor.

[0206] In the first reactor, the biomass, whose majority of cellulose and hemicellulose components have been converted into reducing sugars, is exposed to a fresh enzyme solution. With the help of the cellulase@MOF system, which still retains relatively high activity, this fresh solution saccharifies the remaining cellulose and hemicellulose in the hydrolyzed biomass, producing reducing sugars. The solution from the penultimate reactor also enters the final reactor. In the final reactor, the solution containing cellobiose and other monosaccharides is mixed with the cellulase@MOF catalyst, and the remaining cellobiose is converted into glucose. In each existing biomass reactor, these are mixed with the enzyme solution and the cellulase@MOF catalyst at a temperature of 50 to 60 degrees Celsius for a certain period of time (1 to 2 days).

[0207] This innovation addresses the problems existing in current saccharification systems. As mentioned, traditional batch systems consume large amounts of enzymes, while countercurrent methods can largely solve this problem. However, in countercurrent reactors, the reaction time must be limited due to the inhibitory effects of sugars and lignin, which reduces saccharification efficiency. The cellulase@MOF system overcomes this limitation by reducing the inhibitory effects of sugars and lignin. Furthermore, countercurrent systems require the addition of fresh enzyme solution and β-glucosidase supplements during the process. However, the presence of the cellulase@MOF catalyst, which moves along the system with the biomass, solves this requirement and saves on enzyme consumption. In the final step, the final sugar solution enters the reactor containing cellulase@MOF, and the remaining cellulose and cellobiose are converted into sugars, resulting in an increased conversion percentage.

[0208] exist Figure 4In the process, fresh enzyme / buffer solution (FRESHENZ) enters the SACC3 reactor and is mixed with cellulose (BIO2OUT) previously used for saccharification in SACC2. SF3 is the mixture of FRESHENZ and BIO2OUT entering the SACC3 reactor. It must be noted that a mixer (MIX3) is required in the flow diagram design due to limitations in the simulator's ability to introduce feed streams into the reactor. However, this is unnecessary; the two streams can enter SACC3 without initial mixing. Thus, after the saccharification reaction occurs in the SACC3 tank, product SP3 is discharged from the reactor; this stream contains residues of the cellulose component used three times (now waste (BIO3OUT)) and a sugar solution (SUG1ENZY) produced mixed with the enzyme / buffer solution. BIO3OUT is waste without any remaining sugar to be produced and is disposed of; SP3 passes through a separator (SEP3) to separate SUG1ENZY and BIO3OUT from each other, and then SUG1ENZY enters SACC2 for further use. Therefore, a separator must be used after each saccharification reactor. Then, as previously mentioned, SUG1ENZY enters SACC2 and is mixed with the cellulose component (i.e., BIO1OUT) that has been used once from tank SACC1.

[0209] This is the same as described regarding SACC3 and what has already happened; thus, for SACC2, BIO1OUT and SUG1ENZY are mixed (due to simulator limitations, mixer MIX2 has to be used), and enter the SACC2 tank as SF2, which is the feed material stream for SACC2 (it is worth noting that mixer MIX2 is not actually necessary). After the saccharification process occurs in SACC2, the SP2 product material stream exists in SACC2. The SP2 product material stream contains a more saturated sugar solution containing a mixture of enzyme / buffer solution (SUG2ENZY) and a residue of partially used cellulose (because it has already been used once in SACC1). This partially used cellulose will be used in SACC3, called BIO2OUT. The separator (SEP2) is used to separate SUG2ENZY and BIO2OUT from each other. Thus, SUG2ENZY enters SACC1 to be mixed with untreated and fresh cellulose from the hydrothermal process.

[0210] This is the same as described for SACC3 and SACC2, and what has already happened; thus, for SACC1, the feed stream to the SACC1 reactor is SF1, which contains fresh / untreated cellulose (HEMICELL) from the pretreatment step and a partially saturated sugar solution (SUG2ENZY) mixed with a twice-used enzyme / buffer solution. Due to simulator limitations, a mixer (MIX1) is shown in the flow chart, but as previously mentioned, it is not actually necessary. After the saccharification step, the product is discharged as SP1. SP1 contains the final concentrated sugar solution (FINALSUG) and treated / once-used cellulose (BIO1OUT), the final concentrated sugar solution (FINALSUG) which will be used in the fermentation step. A separator (SEP1) must be used to separate FINALSUG and BIO1OUT from each other. Thus, the FINALSUG feed stream will be used in the fermenter to produce crude ethanol, while the BIO1OUT will be used in SACC2.

[0211] In the first reactor, the inlet stream SF1 consists of fresh / untreated cellulose (HEMIELL) from the pretreatment step and a partially saturated sugar solution (SUG2ENZY) mixed with an enzyme / buffer solution. The outlet stream SP1 consists of the final concentrated sugar solution (FINALSUG) and treated / used cellulose (BIO1OUT).

[0212] In the second reactor, the inlet stream SF2 consists of cellulose that has been used once (BIO1OUT) and a sugar solution produced once (SUG1ENZY) mixed with an enzyme / buffer solution. The outlet stream SP2 consists of a partially saturated sugar solution mixed with an enzyme / buffer solution (SUG2ENZY) and cellulose that has been used twice (BIO2OUT).

[0213] Finally, in the fifth reactor, the inlet stream SF5 consists of cellulose used four times (BIO4OUT) and fresh enzyme / buffer solution (FRESHENZY). The outlet stream SP5 consists of a single-production sugar solution mixed with enzyme / buffer solution (SUG1ENZY) and cellulose used five times (BIO5OUT).

[0214] Cellulose that has been used five times (BIO5OUT) will be cleaned up, and the final concentrated sugar solution (FINALSUG) will be fed into the fermentation reactor.

[0215] The reactors have the same specifications and characteristics and operate under the same conditions. The saccharification temperature is from about 35°C to about 50°C, preferably from about 40°C to about 45°C. The applied pressure is about 0.5 atm (5 × 10⁻⁶). 5Pa) to 2 atm (2×10 5 Pa), preferably 1 atm (1×10 Pa), preferably 1 atm (1×10 Pa) 5 Pa).

[0216] Step V – Fermentation Step

[0217] The fermentation step (step V) is performed using a fermenter. The raw materials include many microorganisms, such as yeast and bacteria. Typically, *Saccharomyces cerevisiae* and *Megaserulum cirrhosa* are responsible for performing the fermentation. In this disclosure, *Saccharomyces cerevisiae* is added to the fermenter.

[0218] One of the byproducts of this process is carbon dioxide.

[0219] For this disclosure, the first phase of production will last approximately 2-3 days (batch process). After that, the process will transition to a semi-continuous or continuous process, thereby allowing for the daily production of 2G of bioethanol.

[0220] The fermentation process is carried out at a temperature of about 30°C to about 40°C, preferably about 32°C to about 35°C, for 3-4 days. Similar to the saccharification process, a pressure of about 0.5 atm (5 × 10⁻⁶) is applied. 5 Pa) to 1 atm (1×10 5 Pa), preferably about 0.7 atm (7×10 Pa). 4 Pa) to approximately 0.9 atm (9 × 10) 4 Pa).

[0221] Step VI – Distillation Step

[0222] After leaving the fermenter, the diluted crude ethanol feed stream enters a continuous centrifuge. The centrifuge separates the diluted crude ethanol into two feed streams: a fermentation broth feed stream and a water / crude ethanol mixture feed stream. The crude ethanol mixture then enters a falling film distillation column for purification. The waste residue of water / crude ethanol / fermentation broth exits from the bottom of the column, and the final product 2G of bioethanol is produced from the top of the column by condensing ethanol vapor. For this disclosure, the distillation unit is a falling film evaporator (FFE) column 154 coupled to a thermosiphon condenser 103.

[0223] A low concentration of crude ethanol, including ethanol, enters the FFE 154 to increase the ethanol concentration to the azeotropic point (95.6%). For example, hot steam at a temperature of approximately 70°C to approximately 90°C is present in the falling film tube 156. The feed is then heated using this hot steam, instead of using a boiler located at the bottom of the falling film tower. The steam from the FFE then enters the thermosiphon cooling system 103.

[0224] exist Figure 5In the process details, the feed enters the column via inlet (A) 155; as the feed is inside the column, small plates impact the feed in the top portion of the falling film channel 156, resulting in better feed distribution. Then, the column is filled with hot steam via steam inlet (B) 106. The steam passes through channel 156, heating the feed inside the channel and flowing down the column. At the end of the falling film process, the hot steam loses its temperature due to heating the feed inside and remains in the column via outlet (D) 105.

[0225] The feed is then distilled due to falling film transport, which causes the concentrated slurry to be discharged as residue from the bottom of the small channel. The residue is discharged from the bottom section (E) 157 of the column as a heavier and more concentrated form of the feed, while the distillate moves (F) for further separation and is then discharged to the condenser via the top outlet.

[0226] As shown in the figure, part (F) is a simple flash tank 158, which operates to separate liquid from vapor for higher production yield.

[0227] When the distillate enters condenser 103, it passes through a series of coiled pipes 160, then condenses and remains at the bottom outlet 163 of the condenser. The condenser is filled with a refrigerant, for example, R134a, water, NH4OH, or similar substances, as the primary source for cooling ethanol vapors.

[0228] Figure 7A , Figure 7B and Figure 7C The thermosiphon column (heat pipe) 160 is positioned to create a natural refrigerant circulation during continuous system operation. When ethanol vapor enters the condenser 103, the ethanol vapor imparts its heat to the refrigerant and condenses into a liquid. Now the refrigerant is hot and in a lighter state, it exists in the upper part of the bottom chamber and enters the upper chamber 102, which is cooled by the fan 161. When the refrigerant is sufficiently cooled and becomes heavier, it exists in the upper chamber 102 and enters the lower part of the bottom chamber 102.

[0229] This thermosiphon 103 consists of a refrigerant-containing storage tank 102 connected by a heat pipe 160. The heat pipe 160, containing hot vapor (such as ethanol), enters the refrigerant-containing storage tank 102 and heats the liquid refrigerant as it passes through the tank. Due to the density difference, the heat is transferred through the heat pipe 160 to another storage tank 102 equipped with a fan 161. The cooled liquid returns to the first storage tank 102 due to the increased density (heat transfer) and is used to cool the pipe containing the hot vapor.

[0230] It is worth noting that the thermosiphon 103 is a passive cooling system that relies on gravity to circulate the refrigerant fluid, rather than on a capillary wick structure. The benefits of these systems include compact design, water conservation, and the ability to operate for extended periods without external power.

[0231] When 2g of hot bioethanol passes through the tube, the refrigerant absorbs heat, and the 2g of bioethanol cools. Due to the density difference, the heated refrigerant enters the upper chamber 102 without a pump and is cooled by a dedicated fan 161, and then returns to the main storage tank due to the density and gravity difference. The heated refrigerant enters the upper chamber 102 without a pump and is cooled by a dedicated fan 161, and then returns to the main storage tank due to the density and gravity difference. Ethanol vapor can be cooled using a thermosiphon cooler 103 without a pump and additional power consumption. The cooled 2g of bioethanol then enters the chamber containing powdered molecular sieves 164.

[0232] Molecular sieve 164 consists of synthetic beads with small pores. The pores are large enough to allow water molecules to pass through, but small enough to restrict the inflow of ethanol into the beads. Molecular sieve 164 is widely used due to its high adsorption capacity, strong thermal stability, and other advantages. Water saturates the beads, and dry ethanol passes through the system. Type 3A molecular sieve 164 is considered the most efficient type for drying ethanol. High temperature and pressure fluctuations vaporize the water within the beads. The beads are reused for further separation. This technique is a physical separation, meaning that azeotropes do not limit the ability to remove water.

[0233] This disclosure also teaches a system for producing 2g of ethanol. The system includes:

[0234] The ultrasonic hydrothermal reactor 172 is configured to convert raw materials into a multiphase mixture of cellulose, hemicellulose and lignin.

[0235] A decanter / separator is configured to receive a multiphase mixture of cellulose, hemicellulose and lignin from an ultrasonic hydrothermal reactor and separate the solid phase from the solution.

[0236] Five or more saccharification countercurrent reactors 146, each configured to convert cellulose and hemicellulose into sugars via a metal-organic framework cellulase complex (cellulase@MOF), a mixer located before each reactor for mixing at least cellulose / hemicellulose and cellulase@MOF, and a separator located after each reactor for separating one or more of the unconverted cellulose / hemicellulose, cellulase@MOF, and glucose;

[0237] The fermenter is configured to receive separated glucose from a mixer located after the first reactor and convert the glucose into diluted crude ethanol and slurry.

[0238] Decanter / separator 230 is configured to receive and separate diluted ethanol and slurry;

[0239] The falling film still 154 has an inlet 155 for diluting ethanol, a top outlet 105 and a bottom outlet 157, wherein the bottom outlet transmits residue and the top outlet transmits 2G of bioethanol vapor.

[0240] The thermosiphon 103 is configured to convert 2G of bioethanol vapor into 2G of liquid bioethanol.

[0241] Different embodiments of the application may include combinations of machines.

[0242] Upstream of UBH reactor 172, the following components may be selected, but are not limited to:

[0243] - A shredder that transforms a raw material stream into shredded straw; and / or

[0244] - A dryer configured for drying straw, wherein the dryer may be a rotary dryer, vertical dryer, fluidized bed, infrared dryer, drum bed, or may be capable of drying under sunlight; and / or

[0245] - Storage silos to extend shelf life; and / or

[0246] - A mixer configured to mix the input of a dry straw stream and the input of a water stream.

[0247] Different decanters or separators can be used. In this disclosure, centrifugal separators are used due to their efficiency and performance.

[0248] In this disclosure, the UBH reactor is used in the process for the pretreatment of biomass to produce biofuels such as 2G bioethanol, biogas and biodiesel.

[0249] Example

[0250] This disclosure refers to the UBH reactor, which includes a reactor body 172, an ultrasonic probe 177, a flexible baffle plate 180, a flexible heating coil 181, a shell (jacket), a top cover 176, and a stirring system 182.

[0251] The reactor body 172 includes a cylindrical and quasi-spherical portion, a product outlet 174, a feed inlet 66, an ultrasonic flange top cover, and a shaft 175 that holds the baffle 180 shown. The reactor body 172 and the top cover 176 are sealed with an airtight flange.

[0252] The reactor body 172 is a 5000-liter conventional cylindrical chemical reactor, which has a quasi-spherical head and bottom.

[0253] At the top of the reactor cylinder, flange 176 is intended to seal the body and top cover together.

[0254] The reactor includes an outlet 174 for discharging the treated straw, which is a conventional cylindrical pipe with a flange head.

[0255] The reactor has a cylindrical shaft 175, which serves as the base for holding the curved baffles 180. The shaft 175 has an internal space that allows the stirring shaft 175 to rotate freely.

[0256] The top cover has two feed inlets, which are formed by two identical ports. Sixteen (16) bolts are used to seal the top cover and reactor flange together. Each feed inlet has a flange with 12 bolts.

[0257] Three ultrasonic retainers 177 are equidistant from the center point, and the three ultrasonic retainers 177 include ends that are equidistant from each other; these retainers 177 are equipped with flanges so that the ports are completely sealed after ultrasonic treatment. Each retainer has a flange with 8 bolts.

[0258] The reactor also includes a thermometer holder, which has the same precise dimensions and characteristics as the ultrasonic holder and is positioned parallel to one of the ultrasonic holders.

[0259] The reactor also includes two pairs of air inlets and outlets for pressure regulation. Each pair of inlets and outlets has a flange with the same characteristics as the other ports with eight bolts.

[0260] The reactor's baffles 180 are curved, each with a circular hole. From a top view, the ultrasonic probe 123 is precisely positioned between a pair of baffles 180. All baffles 180 are equidistant, have a thickness of 0.5 cm, and a radius of 45 cm. The baffles 180 are also positioned 15 cm from the reactor body 172. Each baffle 180 has 7 holes in the horizontal direction and 21 holes in the vertical direction.

[0261] Regarding heating regulation, a tapered spring tube heating coil 181 is used. The coil 181 is wound around the reactor in 13 turns and has an inlet and outlet 183 for steam. The steam port 183 has the same flange characteristics as the ultrasonic retainer flange.

[0262] The stirring system includes a four-bladed conventional diagonal heat sink 182 for stirring.

[0263] The shell serves as a heating jacket, which is considered to enclose the reactor. It has the same inlet and outlet for oil. It also has two bases to fully elevate and hold the reactor. These ports are not strictly necessary. Furthermore, legs can be added to the shell, allowing the reactor to be upright.

[0264] test

[0265] 1.1 Straw content

[0266] 1.1.1 General Industrial Characteristics

[0267] The biomass used in the following tests was rice straw samples.

[0268] Industrial analysis provides insights into the moisture, volatile matter, and ash content of a sample, ultimately estimating the total fixed carbon for a specific sample. Therefore, the rice straw used in this study underwent three analyses.

[0269] The moisture content was found to be 15.6% by mass. Generally speaking, any carbon-containing material with a high percentage of moisture content will hinder the flammability of the substance.

[0270] The ash content in the sample was observed to be 13.4%.

[0271] Similarly, the presence of a high percentage of volatile matter indicates the presence of multiple active sites on the substance. A volatile matter content of 62.8% was found. This, along with a carbon content of 8.3%, ensures a substantial carbon network, which may contribute to sample retention after delignification. Table 2 includes the percentage of content in each analysis.

[0272] Table 2 – Straw content analysis (w / w%)

[0273]

[0274] 1.1.2 Lignin content

[0275] The UV-Vis spectroscopy results related to the total amount of acid-soluble lignin demonstrate the effectiveness of the selected pretreatment method.

[0276] The table below contains data related to the effectiveness of lignin content determination and pretreatment methods.

[0277] Table 3 – Absorbance results of different methods

[0278]

[0279] It is an abbreviation for ultrasound.

[0280] 100 and 120 are temperatures in degrees Celsius.

[0281] like Figure 9 and Figure 10 As can be seen in Table 3, absorbance decreases with the presence of baffles and ultrasound. This means that the 14.05% delignification rate achieved with the new baffles, compared to the 9.64% delignification rate obtained with conventional baffles, confirms an improvement in the degree of delignification.

[0282] 1.2. Effect of baffles on solubility

[0283] Table 4 shows the effectiveness of the presence of the baffles described in this disclosure compared to conventional baffles and the absence of baffles.

[0284] Table 4 – Baffle Plate Test

[0285]

[0286] Therefore, potassium permanganate droplets were added to water in the absence of baffles, in the presence of conventional baffles, and in the presence of novel baffles. The novel baffles were tested under two conditions: first, the curvature of the blades was in the same direction as the solution circulation, and second, the curvature of the blades was in the opposite direction to the solution circulation.

[0287] The data mentioned above show that the solubility in the reactor is significantly increased when baffles are present.

[0288] 1.3 Structural Changes

[0289] 1.3.1 Fourier Transform Infrared Spectroscopy (FTIR)

[0290] FTIR technology was used to study the chemical and structural changes in straw caused by pretreatment. Figure 11 The spectrum of untreated straw can be seen in the image.

[0291] Table 5 lists the assignments of the FTIR peaks corresponding to the functional groups of the lignocellulose components.

[0292] Table 5 – Wavelength

[0293]

[0294] As can be seen, the FTIR spectra of the untreated and treated samples show significant differences in intensity and shape.

[0295] Untreated rice straw is 1600-1610 cm thick. -1 The peaks at 1495-1520 cm⁻¹ show C=C stretching of the lignin aromatic ring.-1 The peaks at 1045-1055 cm⁻¹ show the vibrational stretching of the C=C aromatic ring skeleton of the lignin benzene ring. -1 The peak at 780 cm⁻¹ shows the C–O–C stretching of primary alcohols in cellulose and hemicellulose. This spectrum was used to examine the baffle effect as well as temperature and ultrasound. -1 The first peak observed corresponds to the C–H groups present in lignin and the out-of-plane vibrations of the C–H groups in lignin.

[0296] like Figure 12 As can be seen from the FTIR spectra, all functional groups in the pretreated rice straw samples were detected in the untreated rice straw samples when baffles were present.

[0297] However, after pretreatment, lower intensities of these peaks were observed, indicating the dissolution of lignin and some hemicellulose components. (1320 cm⁻¹) -1 (CO of lilac base) and 1268 cm -1 The characteristic lignin peak at (CO of the guaiac ring) has been significantly reduced.

[0298] Figure 12 Notably, the peak intensity showed a greater decrease in the presence of baffles compared to the absence of baffles. Furthermore, the baffles designed by our researchers exhibited the lowest peak intensity.

[0299] Furthermore, compared to the raw materials, the CH deformation of the glucose ring in the cellulose and hemicellulose of the pretreated samples was 885-890 cm⁻¹. -1 The higher strength at this location also indicates changes in the cellulose structure after the pretreatment step. (3400-3200cm) -1 The broadband and 2910 cm -1 The signals at these locations are attributed to OH stretching and CH bonding, respectively. These bands are sensitive to the characteristic features of cellulose. The decrease in the transmission peak of OH vibrations in pretreated rice straw is likely due to a reduced percentage of lignin, which enhances the interaction between radiation and cellulose.

[0300] One of the effects of pretreatment is the removal of wax from straw. Pretreated straw samples were taken at approximately 2850 cm³. -1 and 2920 cm -1 The decrease in the CH2- stretching band at this point indicates a reduction in the amount of aliphatic components in the wax. It can be seen that the pretreated straw at 1735 cm⁻¹ represents a decrease in the amount of hemicellulose. -1 The carbonyl band at [location] decreased. This is expected, as the pretreatment is known to remove most of the hemicellulose. In other words, the carbonyl band at 1720 cm⁻¹ corresponds to the C=O functional group. -1The nearby signals are the acetyl, feruloyl, and p-coumaryl groups that link the hemicellulose and lignin esters. The characteristic peak of the lignin-ester bond is almost completely absent. The near disappearance of this peak indicates that the pretreatment removed lignin through ester bond cleavage.

[0301] These results are consistent with chemical composition analysis and confirm that the pretreatment resulted in a decrease in lignin content and an increase in cellulose content, indicating that lignin degradation was well achieved and that the straw structure was suitable for the hydrolysis process.

[0302] exist Figure 11 Middle, 900 cm -1 The signal at this location was also attributed to β-1,4-glycosidic linkages, thus revealing the typical structure of cellulose. 1735 cm -1 The band at 1510 cm⁻¹ represents the characteristic peak of the hemicellulose-lignin complex. In pretreated rice straw, the intensity disappears, indicating that alkaline pretreatment not only hydrolyzes lignin components but also extracts some hemicellulose. In NaOH-pretreated straw, the band at 1510 cm⁻¹... -1 The peak at 1510 cm⁻¹ (derived from the guaiac ring of lignin) has largely disappeared, indicating significant delignification. The saponification reaction between NaOH and the intermolecular ester bonds in lignin is a key factor leading to structural changes in lignocellulose after NaOH pretreatment, which facilitates lignin removal and cellulose release. In untreated straw, the peak at 1510 cm⁻¹ is observed. -1 This spectral band at that location.

[0303] The (120+ultrasound(ultra)) spectrum showed the most significant structural changes, while the (100) spectrum showed the smallest changes. In the pretreated sample, the 3330 cm⁻¹ represents the stretching of OH. -1 The band at 1430 cm⁻¹ shifts to higher intensities, indicating an increase in free hydroxyl groups and a decrease in intermolecular hydrogen bonds. -1 and 897 cm -1 The absorption bands at 1430 cm⁻¹ represent crystalline cellulose I and amorphous cellulose II, respectively. After pretreatment, the absorption bands at 1430 cm⁻¹... -1 The spectral band at 897 cm⁻¹ decreased, while at 897 cm⁻¹... -1 The bands at that point became stronger, which means that the pretreatment reduced the crystallinity of the cellulose.

[0304] 2852 cm -1 2925 cm -1 and 2935 cm -1 The absorption band at 1600 cm⁻¹ is characteristic of lignin structure, corresponding to symmetric and asymmetric CH stretching of CH₃, CH₂, and CH₄. This absorption band weakens after pretreatment, possibly due to lignin depolymerization. In pretreated biomass, the absorption band at 1600 cm⁻¹...-1 The near disappearance of the band at 3100 cm⁻¹ (due to the stretching of the aromatic benzene ring in lignin) indicates partial removal of lignin. Major changes in the functional groups of the rice straw components (hemicellulose, cellulose, and lignin) were observed. The strong broad band between 3100 cm⁻¹ and 3500 cm⁻¹ is attributed to the OH stretching vibration of lignin. In untreated rice straw, the infrared spectrum at 3409 cm⁻¹ is due to the presence of phenolic and alcoholic hydroxyl groups.

[0305] Based on FTIR data, we can understand the significant importance of ultrasound in increasing delignification efficiency.

[0306] 1.3.2. Scanning Electron Microscopy (SEM) Analysis

[0307] The microstructure and morphology of untreated and pretreated biomass were determined using scanning electron microscopy. Figure 14 and Figure 15 The image shows scanning electron microscope (SEM) images of untreated rice straw (RS), straw treated with a baffled flow system, and straw treated with a baffled flow system for 15 minutes. Figure 14 and Figure 15 It indicates the changes in the surface morphology of rice straw.

[0308] After pretreatment, the surface roughness increased, and the presence of baffles resulted in a higher surface roughness compared to the absence of baffles. Therefore, the baffles are more effective in increasing the surface area of ​​the rice straw, which is beneficial for the action of enzymes and microorganisms, thereby promoting biofuel production. The increase in the surface area of ​​the rice straw can be attributed to the degradation of lignin and hemicellulose, which enhances the amorphous properties of cellulose.

[0309] The structural changes in rice straw caused by the pretreatment process were studied using scanning electron microscopy.

[0310] like Figure 14 The untreated rice straw exhibits a rigid and highly ordered structure. Furthermore, the surface contains tiny spots called papillae and silica-containing structures called phytoliths, which exist in larger, blocky forms. After pretreatment, cellulose fibers are clearly exposed on the surface, adjacent to dumbbell-shaped silica bodies, indicating the disruption of microfibrils and cellular structures such as the cuticle, silica layer, and silica bodies, along with lignin.

[0311] The absence of these surface groups, along with the clean cellulose fibers, helps improve enzyme accessibility to cellulose, resulting in good degradation rates and saccharification properties. Since a significant amount of hemicellulose and lignin components are removed after pretreatment, examining the morphological changes in rice straw using scanning electron microscopy becomes meaningful.

[0312] Figure 14 , Figure 15 and Figure 16 The image shows longitudinal sections of rice straw before and after pretreatment. As we observed, significant morphological changes did indeed occur. Untreated rice straw exhibited rigid and highly ordered fibrils, while the fibers in the pretreated sample were twisted. Furthermore, the microfibrils separated from the initial interconnected structure and were fully exposed, thus increasing the outer surface area and porosity of the rice straw.

[0313] As can be seen, the untreated rice straw exhibits a complete physical structure, without cracks or cavities, and is covered by a complete waxy coating.

[0314] In summary, pretreatment in the presence of NaOH and at different temperatures resulted in structural changes on the biomass surface due to the effective removal of the cuticle wax and silica layers. The use of UBH reactors facilitated the formation of more porous structures and an increase in biomass surface area. Their modified structure allowed for improved enzyme accessibility to the internal cellulose filaments within the substrate.

[0315] 2. Hydrolysis / saccharification steps

[0316] 2.1. Saccharification Method

[0317] In the laboratory, using multiple centrifuge bottles to achieve countercurrent movement of solids and liquids is convenient and practical. The countercurrent test was designed as a 5-bottle (5-step) process. Each container was filled with 30% rice straw substrate and citrate buffer, and then 0.002 g of enzyme per gram of rice straw was added.

[0318] Samples were taken from the fifth container every day (every 24 hours). During this period, the sugar solution and solid substrate moved in opposite directions inside the container, and the sugar solution left the third container. Finally, on the last day, the solutions from all five containers were mixed together.

[0319] Along with this reaction, a simple one-pot hydrolysis was used as a control reaction, which has the same enzyme concentration and substrate weight as the countercurrent method.

[0320] The results were analyzed by determining the amount of sugar produced using HPLC.

[0321] Based on HPLC chromatographic results, the optimal performance of enzymatic hydrolysis depends on the efficient use of the enzyme. Compared to conventional methods, countercurrent saccharification allows for a several-fold reduction in enzyme loading. Table 6 shows the amount of sugar produced during each of the two methods, simple hydrolysis and countercurrent hydrolysis.

[0322] Table 6 – Sugar content after hydrolysis

[0323]

[0324] Because the difference between batch hydrolysis and countercurrent hydrolysis will be greater once the volume and number of countercurrent bottles are increased, the experimental results are favorable.

[0325] CCH demonstrates its high efficiency when more steps are used in the process.

[0326] The CCH system maximizes conversion rate, minimizes enzyme requirements, and reduces enzyme load requirements while maintaining high conversion and high product concentration.

[0327] 2.2. Biomimetic mineralization method and catalyst activity determination

[0328] In biomimetic mineralization methods, organic solvents, as well as high and low temperatures, are avoided to prevent damage to the enzymes.

[0329] In this disclosure, enzyme-immobilized catalysts are prepared in an encapsulated form (cellulase@MOF) and via a biomimetic method of mineralization in a one-pot process.

[0330] The catalyst is synthesized via the following general route:

[0331] a) Prepare an aqueous solution of the metal salt, and simultaneously prepare a 2 mg cellulase / mL citrate buffer solution;

[0332] b) Preparation of aqueous solutions of organic ligands;

[0333] c) Add solution (a) slowly and dropwise to the stirred solution (b) at room temperature;

[0334] d) After approximately 6 to approximately 12 hours, centrifuge and wash the structure;

[0335] e) Finally, dry and store the structure.

[0336] In this disclosure, the structure is dried by a freeze dryer and stored in a refrigerator at a temperature of about 0°C to about 6°C, preferably about 2°C to about 5°C, and most preferably about 4°C.

[0337] f) The enzyme activity of the catalyst was investigated using DNS reagent and by studying the resulting ultraviolet spectrum at 540 nm.

[0338] Table 7 shows the synthetic yields of cellulase @MAF-7 and MAF-7 prepared by biomimetic mineralization.

[0339] Table 7 – Catalyst Synthesis

[0340]

[0341] Table 8 shows the UV absorption results at a wavelength of 540 nm. The catalyst refers to the enzyme@MOF sample, the control catalyst refers to the MOF without the enzyme, and the synthesis solution refers to the solution obtained by washing the enzyme@MOF catalyst, which contains the remaining enzyme that is not fixed in the structure.

[0342] Table 8 – Ultraviolet Absorption of Catalysts

[0343]

[0344] These results indicate that cellulase@MAF-7 is a sample well-suited for enzyme immobilization.

[0345] Using MOFs as coatings to protect enzymes under harsh conditions provides a new and promising tool for the further development of biocomposites for industrial applications.

[0346] 2.3 Scanning electron microscopy of MOF catalysts

[0347] Figure 18 and Figure 19 Scanning electron microscopy (SEM) images of MAF-7 and cellulase@MAF-7 samples are shown. Although SEM analysis revealed that the structures were not completely dry and the MAF-7 particles were adhered together, the presence of MAF-7 structures is acceptable considering that these structures were prepared in an aqueous environment without heating or pressurization. The distribution of the enzyme on the MAF-7 structures is also clearly visible in the images associated with cellulase@MAF-7.

[0348] 2.4 X-ray diffraction of MOF catalysts

[0349] Figure 20 and Figure 21 XRD spectra of MAF-7 and cellulase@MAF-7 samples are shown. In the XRD spectrum of MAF-7, the characteristic 2θ angles corresponding to these organometallic frameworks are clearly visible (angles 11, 13, 16, 18, 25, and 30). However, in cellulase@MAF-7, due to the presence of the enzyme within the structure, although peaks related to the MAF-7 angles are present, the overall structure exhibits very low crystallinity and has become amorphous. This can indicate the distribution of the enzyme within the structure.

[0350] In summary, the proposed UBH reactor clearly has a significant impact on the pretreatment of biomass, disrupting the stubborn structure of lignocellulose and thus accelerating lignin breakdown without the need for expensive or unsafe additives and / or acidic environments. Using the UBH reactor in the pretreatment step, combined with countercurrent hydrolysis using MOF permeases or encapsulated enzymes (which can be reused during the process), not only accelerates the process but also provides a higher sugar content to the fermentation broth, thereby reducing residue discharge. The falling film coupled with a thermosiphon also reduces energy costs.

[0351] Compared to 9.64% using conventional baffles, the UBH reactor of this disclosure provides a delignification rate of 14.05% (a solubility improvement of over 45%). Therefore, the proposed baffle solubility (32%) is more than 7% higher than that of conventional baffles. Consequently, the pretreatment efficiency exceeds 51%.

[0352] In addition, during the hydrolysis / saccharification step, results showed that using the CCH system maximized conversion, minimized enzyme demand, and reduced enzyme load while maintaining high conversion and product concentration. The use of cellulase@MOF during this stage also improved process efficiency and reduced enzyme consumption.

[0353] In the case of distillation in the final stage, a falling film coupled with a thermosiphon is used to reduce process time, cost and energy consumption by eliminating the condenser.

[0354] In summary, the proposed second-generation bioethanol production not only provides a more economical and faster way to reduce competition between biofuels and food, but also alleviates energy problems and mitigates current agricultural waste pollution.

[0355] The descriptions of different exemplary methods are for illustrative and descriptive purposes only and should not be exhaustive or limited to the described methods. Many modifications and variations will become apparent to those skilled in the art. Furthermore, different exemplary embodiments may provide different features compared to other exemplary embodiments. The selected and described embodiments are intended to better explain the principles and practical application of the embodiments and to allow those skilled in the art to understand the descriptions of various embodiments with various modifications suitable for a particular intended use.

[0356] List of references:

[0357] 1- Mariano, A. P. B., Unpaprom, Y., Ponnusamy, V. K., & Ramaraj, R.(2021). Bioethanol production from coconut pulp residue using hydrothermaland postalkaline pretreatment. International Journal of Energy Research,45(6), 8140-8150.

[0358] 2- Cirujano, F. G. (2019). Engineered MOFs and enzymes for thesynthesis of active pharmaceutical ingredients. ChemCatChem,11(23), 5671-5685.

[0359] 3- Fang, R., Dhakshinamoorthy,A., Li, Y., & Garcia, H. (2020). Metalorganic frameworks for biomass conversion. Chemical Society Reviews, 49(11),3638-3687.

[0360] 4- Battisti, R., Machado, R. A., & Marangoni, C. (2021). ComparativeStudy of the Separation of a Binary Mixture Ethanol-Water and 2G-Ethanol in aPilot-Scale Thermosiphon -Assisted Falling Film Distillation Unit. ChemicalEngineering Transactions, 86, 1099-1104.

[0361] 5- Cao, C., Xie, L., Xu, S., Liu, Q., & Du, Y. (2020). Improved HeatTransfer Performance of Falling Film Evaporator for Desalination Industry byBalanced Liquid Distribution. Industrial & Engineering Chemistry Research, 59(46), 20492-20503.

[0362] List of Numbers

[0363] 66. Inlet for untreated materials, see Figure 5 and Figure 6

[0364] 73. Stirring motor

[0365] 102 Refrigerant Tank

[0366] 103 Thermosiphon Body

[0367] 105 Steam outlet

[0368] 106 Steam Inlet

[0369] 123 Ultrasonic probe, see Figure 2 and Figure 3

[0370] 145 Countercurrent feed inlet

[0371] 146 Second Countercurrent Reactor

[0372] 147 Last Countercurrent Reactor

[0373] 148 Countercurrent Exit

[0374] 154 FFE

[0375] 155 FFE feed inlet

[0376] 156 FFE channels

[0377] 157 Falling film residue outlet

[0378] 158 Separator Tank

[0379] 159 Thermosiphon Inlet

[0380] 160 heating pipe

[0381] 161 Fan

[0382] 163 Thermosiphon outlet

[0383] 164 molecular sieve

[0384] 172 Reactor body, see Figure 1 , Figure 2 and Figure 3

[0385] 174. Export of reactor products, see [link / reference]. Figure 1 and Figure 2

[0386] 175 Agitator shaft, see Figure 2 and Figure 3

[0387] 176 Reactor top cover

[0388] 177. Ultrasonic retainer, see [link / reference] Figure 3

[0389] 178 Thermometer

[0390] 180° curved baffle

[0391] 181 Heating / cooling coils inside the reactor, see [reference needed] Figure 2 and Figure 3

[0392] 182. Blades inside the reactor, see [reference]. Figure 2 and Figure 3

[0393] 183 Coil oil inlet / outlet

[0394] 230 centrifuge

[0395] 231 Reflux enzyme inlet

[0396]

[0397]

[0398]

Claims

1. A method for producing 2G of bioethanol, comprising the following steps: i. Obtaining raw materials; ii. Perform physical pretreatment on the raw materials; iii. The material leaving step ii is subjected to hydrothermal pretreatment to form a mixture of lignin, cellulose and hemicellulose, wherein the hydrothermal pretreatment includes converting the material in an ultrasonic baffled hydrothermal (UBH) reactor (62); iv. In the presence of enzymes, the cellulose and hemicellulose are converted into glucose and xylose; v. To ferment sugars into diluted crude ethanol; vi. Distilling the crude ethanol; and vii. Obtain 2G of bioethanol products.

2. The method according to claim 1, wherein, Step iii also includes: a. Crush the raw materials; b. Drying the pulverized raw materials to produce dried straw; and c. Mix the dried straw with water.

3. The method according to claim 1, wherein, Step iii also includes: The cellulose / hemicellulose and wet lignin are separated; and The wet lignin is dehumidified.

4. The method according to claim 1, wherein, Add NaOH to the reactor in step iii.

5. The method according to claim 1, wherein, Step iv is performed in three or more countercurrent saccharification (CCH) reactors, each reactor being configured to convert cellulose / hemicellulose into sugars via a metal-organic framework cellulase complex (cellulase@MOF), wherein the cellulase is at least one of permeation cellulase and encapsulation cellulase, and wherein the metal-organic framework is selected from the group comprising ZIF-7(Zn), MOF-199 and MAF-7(Zn).

6. The method according to claim 1, wherein, Step v is performed at a temperature of 30°C to 45°C and 0.5 atm (5 × 10⁻⁶). 5 Pa) to 1 atm (1×10 5 The operation is carried out under a pressure of (Pa).

7. The method according to claim 1, wherein, Step vi includes distilling the diluted ethanol in a falling film evaporator at a temperature of about 70°C to about 90°C.

8. The method according to claim 1, wherein, Distillation also includes using a thermosiphon to convert gaseous bioethanol into liquid bioethanol.

9. A system for producing bioethanol, comprising: a. An ultrasonic baffled hydrothermal (UBH) reactor (62) configured to convert raw materials into a wet material stream of cellulose / hemicellulose and lignin as described in claim 1; b. A decanter / separator configured to receive a wet material stream of cellulose / hemicellulose and lignin from an ultrasonic hydrothermal reactor and to separate the cellulose / hemicellulose from the wet lignin; c. Five or more countercurrent saccharification (CCH) reactors, each configured to convert cellulose / hemicellulose to sugars via a metal-organic framework cellulase complex (cellulase@MOF), wherein only the final sugar solution and cellulase@MOF are mixed in one reactor at the end, a mixer is located before each reactor for mixing at least the cellulose / hemicellulose and the cellulase@MOF as well as the free enzyme, and a separator is located after each reactor for separating one or more of the unconverted cellulose / hemicellulose, cellulase@MOF, and glucose solution; d. A fermenter configured to receive separated glucose from a mixer located after the first reactor and convert the glucose into diluted crude ethanol and slurry; e. A decanter / separator configured to receive the diluted crude ethanol and separate the diluted crude ethanol into low bioalcohol and slurry; f. A falling film still having an inlet, a top outlet, and a bottom outlet for the low-bioethanol crude ethanol, wherein the bottom outlet delivers residue and the top outlet delivers gaseous bioethanol; g. A thermosiphon configured to convert the gaseous bioethanol into liquid bioethanol.

10. An ultrasonic baffled hydrothermal (UBH) reactor (62) for biomass pretreatment, comprising: i) The reactor body (172) is coupled to a flanged top cover; ii) wherein the flanged top cover (176) includes a plurality of inlets for attachment of: an external heating / cooling inlet (183); a shaft (175) aligned with the center of the flanged top cover; and a plurality of ultrasonic probes (123). iii) Wherein, the reactor body (172) includes: iii) a. Inlet (66), for untreated material; iii) b. Bottom section, with an outlet (174) for reactor products; iii) c. Multiple heating / cooling coils (181) located inside the reactor body; iii) d. Air pressure inlet / outlet, located on the top outer side of the reactor body; iii) e. A stirring shaft (175), located inside the reactor body, the stirring shaft being connected to a motor (73), and comprising: iii) ei) A stirring system (182) located at the bottom of the stirring shaft (175); iii) e.ii) A curved baffle (180) is located above the stirring system (182); iii) e.iii) Wherein, the curved baffle (180) is configured to prevent swirling / eddying of the material in the reactor and to increase the mixing rate; and iv) A housing, including a heating jacket (181) having identical inlet and outlet for oil, wherein the housing also includes at least two bases or legs for raising and holding the reactor.

11. The UBH reactor according to claim 10, wherein, The UBH reactor includes 3 to 5 baffles (180), each baffle (180) having 15 to 25 holes, wherein the curved baffles (180) are configured to prevent swirling / eddying of materials in the reactor and to increase the mixing rate, are equally spaced, and each of the curved baffles (180) includes at least one of circular and elliptical holes in the range of 5 to 10.

12. The UBH reactor according to claim 10 further comprises equally spaced ultrasonic retainers (177), and the number of ultrasonic retainers (177) is proportional to the number of baffles (180), such that the number of ultrasonic retainers (177) is in the range of 2 to 5, wherein, Each ultrasonic retainer (177) includes at least one flange with 8 to 16 equidistant bolts; further wherein the flange of the feed inlet includes 12 bolts and the flange of the top cover includes 16 bolts; and wherein the plurality of heating / cooling coils (181) are wound around the reactor in 5 to 20 turns, the plurality of heating / cooling coils (181) having an inlet and an outlet (183) for steam.

13. The UBH reactor according to claim 10, wherein, The stirring system also includes heat sinks ranging from 2 to 6.

14. The UBH reactor according to claim 10, wherein, The temperature in the UBH reactor is in the range of 120°C to 150°C.

15. The UBH reactor according to claim 10, wherein, The pressure in the UBH reactor is in the range of 7 atm (7.1 x 10⁵ Pa) to 13.6 atm (1.27 x 10⁷ Pa).

16. A thermosiphon cooling system for condensing distilled ethanol, comprising: The device body includes an input section and an output section, wherein the device body comprises: a. Inlet (159), used for distillation of ethanol vapor; b. A convoluted pipe (160) transports ethanol from the inlet to the outlet; c. Liquid refrigerant (102); d. Outlet section (163), for ethanol cooled by the system; e. Outlet pipe (160) delivers refrigerant from the main body to the cooling section; f. Cooling section (102), including fan and heating pipes; g. Inlet pipe (160) delivers refrigerant from the cooling section to the main body.

17. The thermosiphon cooling system of claim 16, for cooling ethanol vapor and converting it into a liquid state.

18. A plurality of countercurrent hydrolysis (CCH) reactors (139) for pretreatment of biomass saccharification, comprising: i) Five or more reactors (141) are placed together in sequence; ii) The reactor body (145) is coupled to a flanged top cover; iii) Wherein, the flanged top cover includes multiple inlets for attachment: an external heating / cooling inlet; and a shaft aligned with the center of the flanged top cover; iv) Wherein, the reactor body includes: iv) a. Inlet (146), used for inputting feed material; iv) b. Quasi-spherical bottom portion with an outlet for reactor products; iv) c. Multiple heating / cooling coils located inside the reactor body; iv) d. Air pressure inlet / outlet, located on the top outer side of the reactor body; iv) e. A stirring shaft, inside the reactor body, the stirring shaft being connected to a motor, and comprising: iv) ei) A stirring system located at the bottom of the stirring shaft; iv) e.ii) A curved baffle plate located above the stirring system; iv) e.iii) Wherein, the curved baffle is configured to prevent swirling / eddying of the material in the reactor and to increase the mixing rate; and v) A housing, including a heating jacket having a uniform inlet and outlet for oil, wherein the housing also includes at least two bases or legs for raising and holding the reactor.

19. The CCH reactor according to claim 18, wherein, The UBH reactor includes baffles, wherein the baffles are curved and each baffle has a circular hole. All baffles are equally spaced, and each baffle is 1 cm thick, 10 cm wide, and 140.37 cm high. The baffles are also positioned 2.5 cm from the reactor body. The baffle plates are connected using 0.75-inch bolts.

20. The CCH reactor of claim 18 further comprises a conical spring tube heating coil with an inner diameter of 3 cm and a thickness of 0.5 cm. The distance between the coils is 10 cm. The coil is wound around the reactor in 14 turns and has an inlet and an outlet for steam. The consistent steam ports have the same flange characteristics.

21. The CCH reactor according to claim 18, wherein, The stirring system consists of paired four-bladed conventional diagonal heat sinks and anchor ends. The shaft has a diameter up to 10 cm; the blades have a length of 42.5 cm, a height of 10 cm, and a thickness of 2 cm. The distance between the stirrer and the baffle is 5 cm. The distance between each heat sink is 50 cm, and the base shaft of each heat sink has a diameter of 12 cm and a height of 10 cm.

22. The CCH reactor according to claim 18, wherein, The temperature in the reactor is in the range of 45 ℃ to 55 ℃.

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