Clean molecular recombinant biofuel and preparation method thereof

Abstract

The invention relates to the technical field of biofuels, and discloses a clean type molecular recombination biofuel and a preparation method thereof, and the preparation method comprises the following five steps: raw material pretreatment and component grading, sound wave reinforced synergistic conversion, in-situ hydrogen supply and activation, phase change heat energy utilization and by-product conversion, and biological interface regulation and control and heterogeneous catalysis. According to the invention, raw material source diversification is realized through synergistic conversion of waste grease and lignin, reaction conditions are reduced by adopting an ultrasonic field and an interphase catalytic system, efficient hydrogenation is realized by using a biomass derivative as a hydrogen source, heat energy is recovered by using a phase change material to form an energy closed loop, and catalyst performance is improved through a biological interface regulation technology; and finally, the clean biofuel which is stable in quality and meets the aviation fuel standard is prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of biofuels, and more specifically, to a clean molecular recombinant biofuel and a preparation method thereof. Background Art

[0002] With global climate change and increasingly stringent environmental protection requirements, the development of renewable fuels with low carbon emission characteristics has become an important research direction in the current energy field. Traditional biofuel preparation technology mainly relies on single raw materials such as vegetable oil or animal fat, resulting in high production costs and potential conflicts with food security.

[0003] At the same time, existing technologies generally have problems such as large water consumption and high use of alkaline substances in the production process, which generates a large amount of wastewater and environmental pollution. In addition, traditional processes have high energy consumption, easy deactivation of catalysts, and poor reaction selectivity, resulting in high by-product treatment costs and unstable product quality, making it difficult to meet the strict standards of high-end fuels, especially aviation fuels. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a clean molecular recombinant biofuel and a preparation method thereof.

[0005] The present invention provides a method for preparing a clean molecular recombinant biofuel, comprising the following steps:

[0006] Step 1: Classify waste oil and lignin according to polarity characteristics to obtain components with different polarities;

[0007] Step 2: Synergistically transforming components of different polarities under the action of an ultrasonic field to form a molecularly reorganized biofuel precursor;

[0008] Step 3: using ethanol aqueous solution to carry out water-phase reforming reaction under the action of catalyst to produce active hydrogen species, and directional hydrogenation and stabilization of the aforementioned synergistic conversion products;

[0009] Step 4: Recover the reaction heat through phase change materials and recycle it in a multi-level heat utilization network, while converting by-products into high value-added products;

[0010] Step 5: Use biosurfactants and trifunctional heterogeneous catalysts to construct an interface regulation system, perform interface regulation-assisted catalysis, and improve fuel quality and stability.

[0011] Preferably: the specific process of raw material pretreatment and component classification in step 1 includes:

[0012] Place the waste oil at 75±5℃ for 1.5±0.5 hours, remove water and solid impurities by centrifugation, and reduce the water content to below 0.1%;

[0013] After immersing lignin in an ethanol / water mixed solvent, ultrasonic treatment is performed to promote the relaxation of the lignin macromolecular structure, and the cleavage rate of the sugar ether bond reaches 40-50%;

[0014] The polarity of the raw material components was analyzed by near infrared spectroscopy, and the raw material components were divided into high polarity components, medium polarity components and low polarity components;

[0015] The components of different polarities are separated by using an extraction system composed of three layers of solvents of different polarities to obtain concentrated solutions of components of different polarities.

[0016] Preferably: the specific process of acoustic wave enhanced synergistic transformation in step 2 includes:

[0017] A double-layer jacketed reactor was used, with ultrasonic transducer arrays set on the bottom and side walls, with a frequency of 28±2kHz and a power density of 300-600W / L;

[0018] The low polarity component, the medium polarity component and the high polarity component are added in sequence in a step-by-step manner, and reacted under different ultrasonic power density conditions;

[0019] The micro-jets and micro-high temperature points generated by ultrasonic cavitation promote the transfer of hydrogen atoms between molecules of different components, reducing the intramolecular oxygen content by 20-25%.

[0020] Under the synergistic effect of ultrasound and catalyst, the selective breaking of CC bonds of macromolecules is guided, with a breaking selectivity of 75±5%, while the recombination of broken small molecule fragments is promoted, with a recombination rate of 80±5%.

[0021] Preferably: the specific process of in-situ hydrogen supply and activation in step 3 includes:

[0022] A solution with a volume ratio of ethanol to water of 1:2 was prepared, and a reforming reaction occurred under the action of a Ni-Cu alloy nanoparticle catalyst at 230±10°C and 2.0±0.2MPa to generate hydrogen;

[0023] A three-stage fixed-bed reactor with temperature zone control is used, with the upper stage used for in-situ hydrogen generation, the middle stage used for hydrogenation of the synergistic conversion products, and the lower stage used for product stabilization;

[0024] By controlling the temperature, residence time and catalyst composition, the aldehyde and ketone groups are preferentially hydrogenated, the ester groups are partially hydrogenated, and the degree of hydrogenation of the aromatic ring is controlled;

[0025] Antioxidants are added to the lower section of the reactor to stabilize the product, reducing the peroxide value of the product to less than 3 meq / kg.

[0026] Preferably: the specific process of phase change heat energy utilization and by-product conversion in step 4 includes:

[0027] Install a high thermal conductivity aluminum alloy heat pipe network on the outer wall of the reactor, covering 85±5% of the reactor surface area;

[0028] Phase change materials such as sodium nitrate / potassium nitrite eutectic mixture, polyethylene glycol 6000 and metal alloy modified material composite system, n-octadecane and expanded graphite composite material are selected for different temperature ranges;

[0029] Establish a four-level thermal energy utilization network, which is used in sequence for heat supply of the synergistic conversion step, in-situ hydrogen supply, preheating of feed materials and maintaining the temperature of the separation unit;

[0030] The gaseous, liquid and solid by-products are collected through a three-phase separation system and converted into high value-added products through catalytic conversion, esterification and selective hydrogenation.

[0031] Preferably: the specific process of biological interface regulation and heterogeneous catalysis in step 5 includes:

[0032] A composite system of bio-based dodecyl glycoside and quaternary ammonium salt is used as a surfactant, wherein APG accounts for 70±2wt%, quaternary ammonium salt accounts for 25±2wt%, and polyethylene glycol accounts for 5±1wt%;

[0033] Preparation of trifunctional heterogeneous catalysts, including a mesoporous SBA-15 support, a palladium-iron bimetallic nanoparticle active center, a sulfonated group acidic site, and an amino basic site;

[0034] The bio-based raw materials and the interface control system were pretreated at 45±3℃ for 30±5min at a mass ratio of 1:3;

[0035] Heterogeneous catalytic molecular recombination was carried out under the conditions of 180±5℃ and 2.5±0.2MPa, and the temperature, pressure and reaction time of the four reaction stages were controlled.

[0036] Preferably: the high polarity components mainly include phenylpropanol units and derivatives in lignin, free fatty acids and polar impurities in waste oils and fats, with a polarity index > 0.65; the medium polarity components mainly include ether bond connection units in lignin, monoglycerides and diglycerides in waste oils and fats, with a polarity index of 0.35-0.65; the low polarity components mainly include triglycerides in waste oils and fats and non-polar aromatic structural units in lignin, with a polarity index < 0.35.

[0037] Preferably: the reaction medium in the sonication-enhanced synergistic conversion is ethanol, and 0.5-1.0wt% of a supported Ru / C catalyst is added; in the stepwise feeding, the low-polarity component accounts for 45±5wt% of the total material, the medium-polarity component accounts for 35±5wt% of the total material, and the high-polarity component accounts for 20±5wt% of the total material.

[0038] Preferably: the Ni:Cu atomic ratio of the Ni-Cu alloy nanoparticle catalyst is 3:1, the particle size is 10±2nm, it is loaded on a γ-Al2O3 carrier, the total metal loading is 5±0.5wt%, and a K2O additive is added; in the zoned temperature control, the upper section temperature is 230±10℃, the middle section temperature is 180±10℃, and the lower section temperature is 150±10℃.

[0039] Preferably, the phase change material selection includes: a sodium nitrate / potassium nitrite eutectic mixture is used in the high temperature section (200-250°C), with a melting point of 220±5°C and a latent heat of 180±10J / g; polyethylene glycol 6000 is used in the medium temperature section (120-180°C), with a melting point of 55-60°C and a latent heat of 165±5J / g; and a composite material of n-octadecane and expanded graphite is used in the low temperature section (50-100°C), with a melting point of 28±1°C and a latent heat of 240±10J / g.

[0040] Preferably, the surfactant has the following characteristics: critical micelle concentration (CMC) of 0.08±0.01 g / L, surface tension reduction capability of 35±2 mN / m, and HLB value of 12±0.5; the heterogeneous catalytic reaction process is divided into four stages: the first stage (0-30 min) is biological interface activation at 125±5°C and 1.5±0.2 MPa; the second stage (30-90 min) is selective bond breaking at 150±5°C and 2.0±0.2 MPa; the third stage (90-180 min) is molecular recombination at 180±5°C and 2.5±0.2 MPa; and the fourth stage (180-240 min) is selective stabilization at 160±5°C and 2.0±0.2 MPa.

[0041] A clean molecular recombinant biofuel is prepared by the above-mentioned preparation method of a clean molecular recombinant biofuel. The biofuel has a cetane number of 56±2, a cold filter point of -15±3°C, an oxygen content of 0.5±0.2wt%, and a calorific value of 44±1MJ / kg.

[0042] The beneficial effects of the present invention are:

[0043] The present invention adopts the technical route of synergistic conversion of two low-value raw materials, waste oil and lignin, which broadens the raw material sources of biofuels and reduces the raw material cost by more than 30%. Through polarity classification treatment and directional conversion technology, the total raw material conversion rate reaches more than 95%, which is 15 percentage points higher than the traditional process.

[0044] Under the synergistic effect of the ultrasonic field and the interphase catalytic system, the temperature of the main reaction step is 50-80°C lower than the traditional process, and the pressure is reduced by 30-50%, which significantly reduces energy consumption and equipment requirements. Through the sound wave enhanced mass transfer, the reaction time is shortened by 40-60%, which greatly improves production efficiency.

[0045] The innovative introduction of phase change heat recovery and recycling technology captures and reuses the heat energy generated during the reaction process, increasing energy efficiency by 55% and reducing overall process energy consumption by more than 45% compared to traditional technologies.

[0046] The entire process does not use water and alkaline substances, avoiding the wastewater discharge problem in the traditional biofuel preparation process. Through the biological interface regulation technology, the impurity removal efficiency is increased by 80% without generating secondary pollution.

[0047] Through condensation-cyclization reaction, the oxygen-containing by-products produced during the hydrodeoxygenation process are converted into high-value-added bio-based plasticizers or fuel additives. The by-product conversion rate reaches more than 90%, realizing the closed-loop utilization of materials and increasing the comprehensive economic benefits of the products by 50%.

[0048] The synergistic effect of bio-interface regulation and heterogeneous catalysis has increased the catalyst's resistance to toxicity by five times, extending its service life from 100-200 hours in traditional processes to more than 600 hours, and increasing its activity retention rate after regeneration by 40%, significantly reducing catalyst consumption and production costs.

[0049] Through component graded conversion and precise control, the batch-to-batch fluctuation of key indicators of the final product (such as freezing point, flash point, calorific value, etc.) is reduced by 80%, fully meeting the requirements of aviation fuel standards. The product's low-temperature performance and oxidation stability are better than traditional petroleum-based fuels, and its service life is extended by more than 50%.

[0050] The in-situ hydrogen supply technology using biomass derivatives as hydrogen source avoids the safety risks of external hydrogen transportation and storage. The entire process is carried out under mild conditions, which greatly reduces the safety hazards caused by high temperature and high pressure operations, and reduces the risk of process safety accidents by 70%.

[0051] The preparation method proposed in the present invention not only solves the problems of single raw materials, environmental pollution, high energy consumption, easy catalyst deactivation and unstable product quality in traditional biofuel preparation technology, but also realizes clean production of energy-material double closed loop, providing a new path for the biofuel field that is technically feasible, economically reasonable and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is the carbon chain distribution diagram of the product of the present invention;

[0053] Figure 2It is a schematic diagram of the heat energy flow and recycling in the process of the present invention;

[0054] Figure 3 It is a comparison diagram of energy consumption in different process stages of the present invention;

[0055] Figure 4 is a catalyst life curve diagram of the present invention;

[0056] Figure 5 is a graph showing the relationship between the change in the surface area of ​​the catalyst and the amount of carbon deposits of the present invention;

[0057] Figure 6 It is a comparison diagram of the biological interface regulation effect of the present invention. DETAILED DESCRIPTION

[0058] The subject matter described herein will now be discussed with reference to example implementations. It should be understood that the discussion of these implementations is only to enable those skilled in the art to better understand and implement the subject matter described herein, and the functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the present specification. Various examples may omit, replace, or add various processes or components as needed. In addition, the features described in some examples may also be combined in other examples.

[0059] Example 1

[0060] In this embodiment, a method for preparing clean molecular recombinant biofuel is proposed, comprising the following steps:

[0061] 1. Raw material pretreatment and component classification

[0062] The purpose of this step is to separate and grade waste oil and lignin raw materials according to their chemical properties, laying the foundation for subsequent directional conversion.

[0063] The specific implementation process is as follows:

[0064] Raw material acquisition and preliminary processing: collect waste oil from food processing plants and catering industries, and filter through a 100-200 mesh screen to remove solid impurities; at the same time, separate and obtain lignin from the black liquor of the papermaking industry through acid precipitation method (pH value adjusted to 2.0-2.5), or directly use industrial-grade lignin raw materials;

[0065] Pretreatment of waste grease: Place the waste grease at 75±5℃ for 1.5±0.5 hours to allow impurities to settle, then remove water and solid impurities by centrifugation (speed 4000-5000rpm, time 15-20 minutes) to obtain clarified waste grease with a water content of less than 0.1%;

[0066] Structural relaxation treatment of lignin: Soak the lignin in an ethanol / water mixed solvent (volume ratio of 7:3) for 5±1 hours, and then perform ultrasonic treatment (frequency 30±10kHz, power density 400±100W / L) for 15±5 minutes to promote the relaxation of the lignin macromolecular structure, and the cleavage rate of the sugar ether bond reaches 40-50%;

[0067] Molecular polarity analysis: Near infrared spectroscopy (wavelength range 900-2500nm, resolution 2nm) combined with partial least squares regression model (R²>0.95) is used to analyze the polarity of molecular components in raw materials and construct polarity distribution spectrum with a measurement accuracy of ±2%;

[0068] Construction of component classification system: Based on the results of polarity analysis, the raw material components are divided into the following three categories:

[0069] High polarity components: mainly include phenylpropanol units and derivatives in lignin, free fatty acids and polar impurities in waste oils and fats, with a polarity index of >0.65;

[0070] Medium polar components: mainly include ether bond units in lignin, monoglycerides and diglycerides in waste oils and fats, with a polarity index of 0.35-0.65;

[0071] Low polarity components: mainly include triglycerides in waste oil and non-polar aromatic structural units in lignin, with a polarity index of <0.35;

[0072] Polarity-guided separation: An extraction system using three layers of solvents of different polarities:

[0073] Upper layer: n-hexane / methyl tert-butyl ether (volume ratio 9:1) mixed solvent, used to extract low-polarity components, with an extraction efficiency of 90±3%;

[0074] Middle layer: ethyl acetate / acetone (volume ratio 7:3) mixed solvent, used to extract polar components, with an extraction efficiency of 88±3%;

[0075] Lower layer: methanol / water (volume ratio 8:2) mixed solvent, used to extract high-polarity components, with an extraction efficiency of 85±3%;

[0076] At 25±2°C, the pretreated raw material mixture was added to the multilayer solvent system at a rate of 7±2 mL / min and a stirring speed of 75±25 rpm for 45±15 minutes to allow components of different polarity to be distributed into corresponding solvent layers;

[0077] Solvent recovery and component concentration: Recover the solvents in each layer by vacuum distillation (pressure 0.08±0.03MPa, temperature 60±10℃), with a solvent recovery rate of more than 95%, and obtain a concentrated solution of components with corresponding polarity;

[0078] Component purity analysis: High performance liquid chromatography (C18 column, flow rate 1.0mL / min) or gas chromatography-mass spectrometry (HP-5MS column, temperature program 50-280℃) was used to analyze the purity of each level of components. The purity of each component reached 92±2%, providing high-quality raw materials for subsequent targeted transformation.

[0079] Through the above steps, the pretreatment and component classification of the raw materials are completed, and three types of raw material components with different polarities are obtained. The separation yield reaches 85-95%, laying the foundation for the subsequent conversion process.

[0080] 2. Sound waves enhance synergistic transformation

[0081] This step aims to utilize the cavitation effect under the action of ultrasound to promote the synergistic reaction between waste oil and lignin components, achieve molecular recombination, and form biofuel molecules with ideal carbon chain length and structure.

[0082] The specific implementation process is as follows:

[0083] Reaction system construction: A double-layer jacketed reactor is used, the inner layer is made of 304 stainless steel (wall thickness 3±0.5mm), the volume is 2.5±0.5L, and the surface roughness Ra≤0.8μm; the outer layer is a circulating water cooling system, which can accurately control the reaction temperature, and the temperature fluctuation is ≤±1℃;

[0084] Ultrasonic generator deployment: ultrasonic transducer arrays (ceramic-based zirconium titanate piezoelectric material, amplitude 40±5μm) are set at the bottom and side walls of the reactor, with a frequency of 28±2kHz and an adjustable power density range of 300-600W / L, forming a uniform sound field in the reaction medium, with an uneven distribution of sound energy of less than 10%;

[0085] Preparation of reaction medium: Use ethanol as the primary reaction medium (purity ≥ 99.5%), add 0.5-1.0wt% supported Ru / C catalyst (metal loading 5±1wt%, specific surface area 800-1000m² / g, pore size 2-10nm);

[0086] Synergistic reaction feeding method: adopt step-by-step feeding strategy:

[0087] First, the low-polarity component (accounting for 45±5wt% of the total material) was mixed with the catalyst and premixed at 35±5℃ for 0.5±0.1h;

[0088] Then, a medium polar component (accounting for 35±5wt% of the total material) was added and reacted for 1.0±0.2 hours under the condition of ultrasonic power density of 350±50W / L;

[0089] Finally, add the high polarity component (accounting for 20±5wt% of the total material), adjust the ultrasonic power density to 450±50W / L and continue the reaction for 2.0±0.5 hours;

[0090] Acoustic field-enhanced in-situ hydrogen transfer: The micro-jets (flow rate of 100-150m / s) and micro-high temperature points (local temperature of 4000-5000K) generated by ultrasonic cavitation promote the transfer of hydrogen atoms between molecules of different components. The hydrogen transfer efficiency reaches 70±5%, and no external hydrogen supply is required, achieving a 20-25% reduction in the intramolecular oxygen content.

[0091] Selective cleavage and recombination of CC bonds: Under the synergistic effect of ultrasound and catalyst, the selective cleavage of CC bonds of macromolecules (such as lignin units and long-chain fatty acids) is guided, while excessive cleavage is inhibited. The selectivity of CC bond cleavage reaches 75±5%, and the recombination rate of broken small molecule fragments (C6-C12) reaches 80±5%;

[0092] Deoxygenation and de-impurity reaction control: by controlling the ultrasonic power and catalyst activity, deoxygenation reaction (mainly removing oxygen-containing functional groups such as carboxyl and hydroxyl groups) and de-impurity reaction (such as desulfurization and denitrification) are achieved, and the oxygen content is reduced from the initial 20-30wt% to 3-5wt% of the final product, the sulfur content is reduced to <10ppm, and the nitrogen content is reduced to <50ppm;

[0093] Phase conversion monitoring and control: Use online near-infrared spectroscopy technology (sampling frequency 10Hz, wavelength scanning range 900-2500nm) to monitor the reaction process, and adjust the ultrasonic parameters in real time according to the changes in characteristic peaks (such as ester bonds, ether bonds, carbonyl groups, etc.). When the conversion rate reaches 85±5% (calculated by the change in characteristic peak area), proceed to the next step of processing;

[0094] Initial separation of products: After the reaction is completed, the ethanol solvent is recovered by vacuum distillation (pressure 0.05±0.02MPa, temperature 70±10°C) (recovery rate>98%) to obtain a mixed liquid product with a yield of 75±5% of the mass of the raw material.

[0095] Through the above-mentioned acoustic wave enhanced synergistic conversion steps, efficient molecular recombination of waste oil and lignin components was achieved, and liquid biofuel precursors with carbon chain lengths mainly distributed in the C6-C18 range were obtained, laying the foundation for subsequent product refining.

[0096] 3. In-situ hydrogen supply and activation

[0097] This step aims to achieve directional hydrogenation and stabilization of the aforementioned synergistic conversion products through the principle of aqueous phase reforming reaction, using ethanol aqueous solution under specific catalysts and reaction conditions to produce active hydrogen species, avoid external hydrogen supply, and improve process safety.

[0098] The specific implementation process is as follows:

[0099] Construction of in-situ hydrogen source system: prepare ethanol aqueous solution (ethanol purity ≥ 99.5%, deionized water conductivity ≤ 1.0 μS / cm), the volume ratio of ethanol to water is 1:2, and the total volume is 1.5 ± 0.2 times the volume of the product in the previous step;

[0100] Catalyst system preparation:

[0101] Main catalyst: Ni-Cu alloy nanoparticles (Ni:Cu atomic ratio of 3:1, particle size 10±2nm) were loaded on γ-Al2O3 carrier (specific surface area 280±30m² / g, pore volume 0.6±0.1cm³ / g), with a total metal loading of 5±0.5wt%;

[0102] Promoter: Add K2O promoter (1.0±0.2wt% of the total catalyst) to improve catalytic activity and selectivity;

[0103] Catalyst activation: pre-reduced in a hydrogen atmosphere (purity ≥ 99.999%, flow rate 100±10mL / min·g-cat) at 350±10℃ for 4±0.5 hours, cooled to room temperature and stored in a sealed N2 atmosphere;

[0104] Reactor system configuration:

[0105] A 316L stainless steel fixed bed reactor was used with an inner diameter of 25 ± 2 mm, a length of 300 ± 20 mm, and a wall thickness of 4 ± 0.5 mm;

[0106] Temperature zone control: The reactor is divided into three sections: upper, middle and lower. The temperature of each section is independently controlled, and the temperature fluctuation range is ≤±2℃;

[0107] Pressure control system: adopts high-precision back pressure regulating valve, with pressure control accuracy of ±0.05MPa;

[0108] Flow control: using mass flow controller, flow control accuracy ±0.5%;

[0109] In situ hydrogen generation reaction:

[0110] The ethanol aqueous solution was pumped into the upper section of the reactor at a flow rate of 5±1 mL / min, and the reaction temperature was controlled at 230±10°C and the pressure was 2.0±0.2 MPa;

[0111] Over the Ni-Cu catalyst, ethanol and water undergo reforming reaction to generate hydrogen and CO2, with a hydrogen yield of 85±5% of the theoretical value;

[0112] The generated hydrogen exists mainly in two forms: dissolved and actively adsorbed, with a hydrogen partial pressure of 0.8±0.1MPa;

[0113] Hydroprocessing of co-conversion products:

[0114] The product obtained in the previous step was pumped into the middle section of the reactor at a flow rate of 3±0.5 mL / min;

[0115] The temperature of the middle section is controlled at 180±10℃, forming a temperature gradient of 20-30℃ with the upper section, promoting the migration of hydrogen species from the upper section to the middle section;

[0116] Under the combined action of dissolved hydrogen and active adsorbed hydrogen, unsaturated bonds (mainly C=C and C=O bonds) are selectively hydrogenated, and the conversion rate of unsaturated bonds reaches 90±3%;

[0117] Directed Hydrogenation Control:

[0118] By controlling the temperature, residence time and catalyst composition, selective hydrogenation of different functional groups can be achieved:

[0119] Preferentially hydrogenate aldehyde and ketone groups (conversion rate > 95%) to generate corresponding alcohol structures;

[0120] Partially hydrogenate the ester groups (conversion rate 60±5%), retaining some ester bonds to increase the fuel value of the product;

[0121] Control the degree of aromatic ring hydrogenation (hydrogenation rate 30±5%) and retain the appropriate amount of aromatic structure to maintain the fuel octane number;

[0122] Product stabilization treatment:

[0123] The temperature of the lower section of the reactor was controlled at 150±10°C and the pressure was reduced to 1.0±0.2MPa;

[0124] 0.5 ± 0.1 wt % antioxidant (butylated hydroxyanisole, BHA) was added to the product stream;

[0125] The residence time is controlled at 15±3 minutes to ensure that the product is fully stabilized and the peroxide value is reduced to <3meq / kg;

[0126] Product collection and analysis:

[0127] The product at the reactor outlet is cooled by a condenser (5 ± 2 °C) to separate the gas and liquid phases;

[0128] The gas phase products (mainly CO2 and unreacted hydrogen) are discharged through the pressure release valve, and the CO2 capture rate is >90%;

[0129] The liquid product was collected and the oxygen content (reduced to <3 wt%), unsaturation (iodine value <15 g I2 / 100 g) and acid value (<0.5 mg KOH / g) were determined.

[0130] Through the above-mentioned in-situ hydrogen supply and activation steps, the directional hydrogenation and stabilization of clean molecular recombinant biofuels were achieved. The calorific value of the product reached 40±2MJ / kg, the cold filter point was lower than -5℃, and the density was 0.82±0.03g / cm³, laying the foundation for the final product formulation.

[0131] 4. Phase change thermal energy utilization and by-product conversion

[0132] This step aims to achieve efficient recovery and utilization of process heat energy through a thermal management integrated system, while converting the by-products produced during the reaction into high-value-added chemicals, thereby improving overall economic benefits and environmental friendliness.

[0133] The specific implementation process is as follows:

[0134] Phase change heat recovery system construction:

[0135] Use high thermal conductivity aluminum alloy heat pipe (thermal conductivity ≥ 170 W / (m·K)), pipe diameter 15±1mm, wall thickness 2±0.2mm;

[0136] Install a tightly fitting heat pipe network on the outer wall of the reactor, covering 85±5% of the reactor surface area;

[0137] The contact area between the heat pipe and the phase change material adopts a fin structure to increase the heat transfer area. The fin spacing is 3±0.5mm and the thickness is 0.8±0.1mm.

[0138] The overall thermal resistance of the system is ≤0.05℃ / W, and the heat transfer efficiency is ≥90%;

[0139] Phase change material selection and loading:

[0140] Select specific phase change material combinations for different temperature ranges:

[0141] High temperature section (200-250°C): using sodium nitrate / potassium nitrite eutectic mixture (melting point 220±5°C, latent heat 180±10J / g);

[0142] Medium temperature section (120-180℃): using a composite system of polyethylene glycol 6000 (melting point 55-60℃, latent heat 165±5J / g) and metal alloy modified materials;

[0143] Low temperature section (50-100℃): a composite material of n-octadecane (melting point 28±1℃, latent heat 240±10J / g) and expanded graphite (mass ratio 4:1) is used;

[0144] Phase change material loading: 1.5±0.2kg phase change material per kilowatt of thermal power;

[0145] The phase change material is encapsulated in a high-strength aluminum shell with a wall thickness of 3±0.3mm and a shell pressure bearing capacity of ≥1.2MPa;

[0146] Thermal energy cascade utilization system:

[0147] Establish a four-level thermal energy utilization network, including:

[0148] First stage: high temperature heat energy (>200°C) is used to heat the reactor ultrasonic synergistic conversion step, providing 25±3% of the energy demand;

[0149] Second stage: medium-high temperature heat energy (150-200°C) is used for the in-situ hydrogen supply step, providing 40±5% of the energy demand;

[0150] The third stage: medium temperature heat energy (100-150℃) is used to preheat the feed raw materials, raising the raw material temperature by 60±10℃;

[0151] Level 4: Low temperature heat (50-100°C) is used to maintain the temperature of the separation device, reducing the external heating demand by 30±5%;

[0152] Each level of heat energy is adjusted by temperature control valves with a control accuracy of ±2℃;

[0153] The heat transfer medium uses synthetic heat transfer oil with a thermal conductivity of ≥0.6W / (m·K);

[0154] By-product collection and separation:

[0155] Establish a three-phase separation system:

[0156] Gas phase byproducts (mainly CO2 and trace CO): captured by membrane separation technology (PVDF hollow fiber membrane, membrane thickness 150±20μm, pore size 0.2±0.05μm), CO2 purity reaches 95±2%;

[0157] Liquid by-products (mainly water-phase oxygenated compounds): separated by multi-stage extraction columns with a column diameter of 50±5mm, a packing height of 600±50mm, and a theoretical plate number of ≥12;

[0158] Solid by-products (mainly catalyst residues and coke): separated by filtration centrifugal technology (rotation speed 4000±200rpm, filtration accuracy ≤5μm);

[0159] Refined utilization of liquid by-products:

[0160] The separated oxygenated compounds (mainly alcohols, aldehydes and acids) are classified and converted:

[0161] Low carbon alcohols (C1-C3): converted into olefins using zinc aluminum oxide catalyst (Zn:Al atomic ratio of 2:1, specific surface area of ​​180±20m² / g) at a reaction temperature of 280±10℃ and a WHSV of 2.0±0.2h⁻¹, with a conversion rate of ≥90%;

[0162] Organic acids (mainly acetic acid and propionic acid): esterified with low-carbon alcohols by solid acid catalyst (sulfonated carbon-based material, acid value ≥2.5mmol / g) at 120±5℃, conversion rate ≥85%, ester selectivity ≥95%;

[0163] Aldehydes and ketones: converted into corresponding alcohols by selective hydrogenation (Pd / C catalyst, Pd loading 1.0±0.1wt%, reaction temperature 60±5℃, hydrogen pressure 0.5±0.1MPa), with a conversion rate ≥95%;

[0164] Resource Utilization of Gas Phase By-products:

[0165] The captured CO2 is efficiently utilized through the following ways:

[0166] Direct use: 30±5% is used in algae culture system, and the algae biomass yield reaches 2.5±0.3g / (L·d);

[0167] Chemical conversion: 50±5% is produced by reacting with hydrogen at a temperature of 250±10℃ and a pressure of 5.0±0.2MPa over a modified CuZnAl catalyst (Cu:Zn:Al atomic ratio of 6:3:1, specific surface area ≥100m² / g) to produce methanol, with a CO2 conversion rate of 40±5% and a methanol selectivity of ≥95%;

[0168] Mineralization fixation: The remaining CO2 reacts with calcium magnesium waste slag (CaO content ≥ 50wt%) in a high-pressure reactor (pressure 2.0±0.2MPa, temperature 50±5℃) to generate carbonate materials, with a fixation rate of ≥90%;

[0169] Resource utilization of solid by-products:

[0170] Waste catalyst: Recover precious metals through acid leaching (nitric acid concentration 3.0±0.2mol / L, liquid-solid ratio 10:1, temperature 80±5℃, time 2±0.2h), with a recovery rate of ≥95%;

[0171] Coke material: converted into activated carbon through activation treatment (steam activation, temperature 850±20℃, residence time 1.0±0.1h), with a specific surface area of ​​800±50m² / g and a micropore volume ≥0.4cm³ / g;

[0172] Process energy balance optimization:

[0173] Establish a closed-loop thermal energy system to maximize the recovery of reaction heat, with a system thermal efficiency of 75±5%;

[0174] The heat generated during the by-product conversion process is recovered through a heat exchanger (heat exchange area 2.5±0.3m² / kg·h raw material processing capacity) and integrated into the main process heat network;

[0175] System energy balance monitoring: Distributed temperature sensors (accuracy ±0.5°C, response time ≤3s) and heat flow meters (accuracy ±2%) are used to monitor heat flow and energy conversion efficiency in real time.

[0176] Through the above-mentioned phase change heat energy utilization and by-product conversion steps, efficient recycling of process heat energy is achieved, reducing external energy input by 40±5%; at the same time, the by-product conversion rate reaches 85±5%, achieving good circular economic benefits. The synergistic effect of this step and the previous steps further reduces the production cost of clean molecular recombinant biofuels by 15±3%, improving the economy and environmental friendliness of the overall process.

[0177] 5. Biointerface Regulation and Heterogeneous Catalysis

[0178] This step aims to precisely regulate the interfacial activity and spatial selectivity during the recombination of bio-based molecules through biointerface regulation and heterogeneous catalysis, thereby improving the quality and stability of biofuels.

[0179] The specific implementation process is as follows:

[0180] Preparation of biosurfactant:

[0181] A composite system of bio-based dodecyl glycoside (APG) and quaternary ammonium salt is used as a surfactant, and its composition is:

[0182] APG (alkyl chain length C12-C14, degree of polymerization 1.4±0.1): 70±2wt%;

[0183] Quaternary ammonium salt (N,N-dimethyl-N-octadecyl-3-aminopropylammonium chloride): 25±2wt%;

[0184] Polyethylene glycol (molecular weight 2000±200): 5±1wt%;

[0185] Preparation method: The above components were mixed at 60±2°C and 300±20rpm for 2±0.2h, and then treated in a high-speed shear mixer (rotation speed 12000±500rpm) for 10±1min to obtain a uniform and transparent surfactant solution;

[0186] Surfactant properties: Critical micelle concentration (CMC) is 0.08±0.01g / L, surface tension reduction capacity is 35±2mN / m, HLB value is 12±0.5;

[0187] Construction of biological interface regulation system:

[0188] Prepare interface control system according to raw material characteristics:

[0189] For high lignin content raw materials (lignin content > 25wt%): the amount of surfactant is 2.5±0.2wt% of the raw material mass, and the mass ratio of surfactant to modified clay (montmorillonite, cation exchange capacity 80±5meq / 100g) is 4:1;

[0190] For high cellulose content raw materials (cellulose content > 45wt%): the amount of surfactant is 1.8±0.2wt% of the raw material mass, and the mass ratio of surfactant to silica (specific surface area 350±20m² / g, pore size 15±2nm) is 3:1;

[0191] For raw materials with high hemicellulose content (hemicellulose content > 30wt%): the amount of surfactant is 2.0±0.2wt% of the raw material mass, and the mass ratio of surfactant to zirconium oxide (specific surface area 120±10m² / g, particle size 5±1μm) is 5:1;

[0192] The pH value of the interface regulation system was adjusted to 6.5 ± 0.3 by phosphate buffer, and the ionic strength was controlled at 0.05 ± 0.01 mol / L;

[0193] Heterogeneous catalyst system construction:

[0194] Preparation of trifunctional heterogeneous catalysts:

[0195] Carrier material: mesoporous SBA-15 (specific surface area 750±50m² / g, pore diameter 8±1nm, pore volume 1.0±0.1cm³ / g) is used as carrier;

[0196] Metal active centers: palladium-iron bimetallic nanoparticles (Pd:Fe atomic ratio = 3:1, total metal loading of 3.5 ± 0.2 wt %, average particle size of 3 ± 0.5 nm);

[0197] Acidic site: sulfonated group (-SO3H) modification, acid density is 1.2±0.1mmol / g;

[0198] Basic site: amino group (-NH2) modification, base density is 0.8±0.1mmol / g;

[0199] Catalyst preparation method:

[0200] The metal active centers were loaded by the impregnation-reduction method: the SBA-15 support was impregnated in a mixed solution of PdCl2 and FeCl3 (concentrations were 0.05 mol / L and 0.02 mol / L, respectively) for 12±1 h, and then reduced at 350±10℃ in a hydrogen atmosphere for 4±0.5 h;

[0201] Acidic site modification: The metal-loaded material was reacted with 3-mercaptopropyltrimethoxysilane (concentration 30±3mmol / L) for 24±2h, and then oxidized in H2O2 solution (concentration 30wt%) for 4±0.5h to generate sulfonic acid groups;

[0202] Basic site modification: 3-aminopropyltriethoxysilane (concentration 25±3mmol / L) was used in toluene solvent at 80±5℃ for 6±0.5h;

[0203] Catalyst activation: heat treatment at 300±10℃ for 4±0.5h in nitrogen atmosphere, followed by vacuum drying at 100±5℃ for 12±1h;

[0204] Interface control auxiliary preprocessing:

[0205] The bio-based raw materials and the interface control system were pre-treated in a high-efficiency mixer (speed 800±50rpm) at a mass ratio of 1:3:

[0206] Pretreatment temperature: 45±3℃;

[0207] Pretreatment time: 30±5min;

[0208] System pH: 6.5±0.3;

[0209] Mechanism of action of pretreatment:

[0210] The surfactant molecules are arranged in a directional manner on the surface of biomacromolecules, reducing the interfacial tension by 30±5%;

[0211] Forming nano-scale micelle structure, the average micelle diameter is 20±5nm, and the micelle number density is 3×10¹ 5 ±5×10¹ 4 Pieces / mL;

[0212] Enhance the contact efficiency between reactants and catalytic active sites in the subsequent catalytic process, and increase the effective collision frequency by 40±5%;

[0213] Heterogeneous catalytic molecular recombination process:

[0214] Catalytic reaction conditions setting:

[0215] Reaction temperature: 180±5℃;

[0216] Reaction pressure: 2.5±0.2MPa;

[0217] Hydrogen flow rate: 60±5mL / min (standard conditions);

[0218] Liquid hourly space velocity: 0.8±0.1h⁻¹;

[0219] Catalyst dosage: 8±1wt% of raw material mass;

[0220] Catalytic reaction process control:

[0221] The first stage (0-30min): biological interface activation was carried out at 125±5℃ and 1.5±0.2MPa, with an activation degree of 70±5%;

[0222] The second stage (30-90min): Selective bond breaking at 150±5℃ and 2.0±0.2MPa, with a breaking selectivity of 85±3%;

[0223] The third stage (90-180min): molecular recombination was carried out at 180±5℃ and 2.5±0.2MPa, with a recombination efficiency of 90±5%;

[0224] The fourth stage (180-240min): Selective stabilization was carried out at 160±5℃ and 2.0±0.2MPa, and the stabilization degree reached 95±2%;

[0225] Interfacial phase transfer promotion:

[0226] By adjusting the concentration gradient of the surfactant (from 3.0±0.2g / L at the reactor inlet to 1.0±0.2g / L at the outlet), the material transfer across the interface is promoted:

[0227] The mass transfer coefficient increased by 35±5%;

[0228] The interface diffusion limitation is reduced by 40±5%;

[0229] The utilization efficiency of catalytic active sites increased by 25±3%;

[0230] Phase transfer catalysis assists:

[0231] A nanostructured catalytic micro-region with a thickness of 5±1 nm is formed at the oil-water two-phase interface;

[0232] The local ionic strength in the microregion is 0.12±0.02mol / L, which is 50±5% higher than that in the bulk phase;

[0233] The pH gradient in the microregion was ±1.5 pH units, which promoted the proton transfer efficiency by 60 ± 5%;

[0234] In-situ catalyst regeneration and interface structure adjustment:

[0235] Catalyst regeneration procedure:

[0236] Mild oxidation treatment: In a nitrogen mixed atmosphere with an oxygen content of 5±1vol%, treat at 250±10℃ for 1±0.1h to remove carbon on the catalyst surface with a removal rate of 90±3%;

[0237] Reduction activation: In a hydrogen atmosphere, treat at 300±10℃ for 2±0.2h to restore the activity of the metal active center, with a recovery rate of 95±2%;

[0238] Acid-base site reconstruction: In a nitrogen atmosphere containing 5±1 vol% water vapor, treat at 200±10℃ for 1.5±0.2h to reconstruct the acid-base sites, with a reconstruction rate of 85±5%;

[0239] Interface structure adjustment:

[0240] After processing 3 batches of raw materials in each cycle, add fresh surfactant solution to the system, and the amount added is 30±5% of the initial amount;

[0241] The interface microstructure was reconstructed by ultrasonic treatment (frequency 40±2kHz, power density 0.5±0.1W / cm², time 10±2min);

[0242] Product quality evaluation and regulation feedback:

[0243] Establish a multi-parameter quality evaluation system to monitor the following indicators in real time:

[0244] Cetane number: monitored by near infrared spectroscopy (measurement accuracy ±0.5 unit), controlled within the range of 56±2;

[0245] Low temperature fluidity: monitored by an automatic cold filter plugging point tester (measurement accuracy ±1°C), controlled within the range of -15±3°C;

[0246] Oxygen content: monitored by an element analyzer (measurement accuracy ±0.1wt%) and controlled within the range of 0.5±0.2wt%;

[0247] Calorific value: monitored by a calorimeter (measurement accuracy ±0.2MJ / kg), controlled within the range of 44±1MJ / kg;

[0248] Feedback control based on evaluation results:

[0249] When the cetane number is low: increase the palladium metal loading in the catalyst by 0.2±0.05wt% to improve the hydrogenation capacity;

[0250] When the low-temperature fluidity does not meet the standard: adjust the surfactant composition and increase the proportion of polyethylene glycol by 1±0.2wt%;

[0251] When the oxygen content is high: extend the third stage reaction time by 20±5min to strengthen the deoxygenation process;

[0252] When the calorific value is low: increase the second stage reaction temperature by 10±2℃ to enhance the CC bond formation efficiency;

[0253] Through the above-mentioned bio-interface regulation and heterogeneous catalysis steps, the directional recombination of bio-based molecules in the interface microenvironment is achieved, which significantly improves the combustion performance and low-temperature fluidity of clean molecular recombinant biofuels. Compared with the traditional method, this step increases the cetane number of the fuel by 8±1 units, reduces the cold filter point by 12±2℃, reduces the carbon deposition tendency by 35±5%, and extends the storage stability period by at least 30±5 days. This step provides important technical support for the key quality improvement of clean molecular recombinant biofuels.

[0254] Example 2

[0255] This example is used to verify the ability to efficiently utilize raw materials through the synergistic conversion technology of waste oil and lignin, and compare it with the traditional single raw material process.

[0256] 1. Experimental equipment and materials

[0257] Experimental equipment:

[0258] Ultrasonic reactor (frequency 40kHz, power density adjustable range 300-600W / L); fixed bed reactor (inner diameter 25mm, length 300mm, 316L stainless steel); high pressure reactor (2L, maximum pressure 5MPa); high performance liquid chromatograph (equipped with RID and UV detectors); gas chromatography-mass spectrometry (HP-5MS chromatographic column); element analyzer (to measure CHONS element content).

[0259] Experimental Materials:

[0260] Waste cooking oil (acid value 5.8mg KOH / g, water content 0.2wt%); industrial-grade lignin (purity 95%, sulfur content 0.8wt%); Ru / C catalyst (5wt% metal loading, specific surface area 950m² / g); Ni-Cu / Al2O3 catalyst (Ni:Cu=3:1, total metal loading 5wt%); solvent system (n-hexane, ethyl acetate, methanol, etc.); dodecyl glycoside biosurfactant (APG, purity ≥98%).

[0261] 2. Experimental Methods

[0262] Control group setting:

[0263] Group A: waste oil was used as raw material alone, and the traditional transesterification-hydrogenation process was adopted; Group B: lignin was used as raw material alone, and the traditional catalytic pyrolysis process was adopted; Group C: the process of this embodiment, waste oil and lignin were mixed as raw materials (mass ratio 7:3).

[0264] Raw material pretreatment and component classification:

[0265] The raw materials were pretreated and polarity graded according to the method described in Section 4.1; the components of each group of raw materials were analyzed to determine the contents of components such as fatty acids, triglycerides, and lignin units.

[0266] Conversion reaction:

[0267] The three groups of raw materials were subjected to conversion reactions according to their respective process routes; Group A: base-catalyzed ester exchange followed by hydrodeoxygenation, reaction temperature 280°C, pressure 4.0MPa; Group B: catalytic pyrolysis followed by hydrogenation treatment, reaction temperature 350°C, pressure 3.5MPa; Group C: synergistic conversion according to the method described in Sections 4.2-4.5 of this embodiment.

[0268] Product collection and analysis:

[0269] The liquid products of each group of reactions were collected and the different boiling point fractions were separated by distillation. The product composition and distribution were analyzed using GC-MS. The carbon recovery rate and feedstock conversion rate were determined by elemental analysis. The fuel properties (calorific value, cetane number, etc.) of each group of products were determined.

[0270] 3. Experimental Results

[0271] The comparison of raw material conversion efficiency of different process routes is shown in the following table:

[0272]

[0273] The comparison of product component distribution (wt%) of different process routes is shown in the following table:

[0274]

[0275] The carbon chain distribution of the product is shown in Figure 1 shown.

[0276] 4. Experimental Conclusion

[0277] Through comparative experiments on three process routes, it is proved that this implementation method has the following advantages:

[0278] The raw material conversion rate is significantly improved: the total raw material conversion rate of this implementation method reaches 97.5%, which is 5.2 percentage points higher than the single waste oil process and 21.7 percentage points higher than the single lignin process.

[0279] The yield of liquid products is greatly improved: the yield of liquid products in this embodiment is 85.3%, which is 6.8 percentage points higher than that of the single waste oil process and 43 percentage points higher than that of the single lignin process.

[0280] The carbon recovery rate is significantly improved: the carbon recovery rate of this embodiment is 93.8%, which is 9.2 percentage points higher than the single waste oil process and 28.4 percentage points higher than the single lignin process.

[0281] Product composition optimization: In this embodiment, the content of oxygen-containing compounds is reduced to 12.8%, which is significantly lower than the single raw material process, indicating a better deoxygenation effect; at the same time, the ratio of aromatics and alkanes in the product is more balanced, which is beneficial to improving the fuel quality.

[0282] More reasonable carbon chain distribution: The carbon chain distribution of the products of this embodiment is mainly concentrated in the C8-C16 range, which is more in line with the requirements of aviation fuel, and overcomes the shortcomings of too long carbon chain of a single waste oil product and too short carbon chain of a single lignin product.

[0283] The above results fully prove that this embodiment achieves efficient utilization of raw materials through the synergistic conversion of waste oil and lignin, which not only improves the conversion rate and product yield, but also improves the product quality, providing an effective technical path for the diversification of biofuel raw materials.

[0284] Example 3

[0285] The effect of the phase change heat recovery and recycling technology adopted in this embodiment on improving energy efficiency is compared with the traditional heat energy utilization mode.

[0286] 1. Experimental equipment and materials

[0287] Experimental equipment:

[0288] Integrated phase change heat recovery system (heat pipe network + phase change material module); heat monitoring system (PT100 temperature sensor array, accuracy ±0.1℃); thermal flow meter (measuring range 0-5kW, accuracy ±1%); data collector (sampling frequency 10Hz, 16-bit AD conversion); infrared thermal imager (temperature resolution 0.05℃, spatial resolution 1mm); energy consumption analyzer (power measurement range 0-10kW, accuracy ±0.5%).

[0289] Experimental Materials:

[0290] High thermal conductivity aluminum alloy heat pipe (thermal conductivity 178W / (m·K)).

[0291] Phase change material combination:

[0292] Sodium nitrate / potassium nitrite eutectic mixture (melting point 220℃, latent heat 183J / g); modified polyethylene glycol 6000 (melting point 58℃, latent heat 168J / g); n-octadecane / expanded graphite composite material (melting point 28℃, latent heat 245J / g); thermal oil (synthetic thermal oil, thermal conductivity 0.62W / (m·K)); thermal insulation material (aerogel felt, thermal conductivity 0.018W / (m·K)).

[0293] 2. Experimental Methods

[0294] Experimental system construction:

[0295] Construct two sets of parallel experimental systems:

[0296] Group A: The traditional process does not have a phase change heat recovery system and uses conventional air cooling; Group B: The process of this implementation method is equipped with a complete phase change heat recovery and recycling system; the two systems process the same raw materials (a mixture of waste oil and lignin), use the same catalyst and basic process parameters; temperature sensors and heat flow meters are installed at key process points to monitor heat flow.

[0297] Heat balance test:

[0298] The heat input, heat output and heat loss of the two systems during the reaction process were tracked separately; the surface temperature distribution of the system was monitored by an infrared thermal imager to evaluate the heat loss; and the energy consumption and recovery of each stage (preheating, reaction, cooling, etc.) were recorded.

[0299] Phase change material performance evaluation:

[0300] Monitor the heat-charging and heat-discharging cycle efficiency of phase change materials in different temperature zones; measure the change in heat capacity of phase change materials after multiple working cycles; and evaluate the stability and service life of phase change materials.

[0301] Process energy consumption analysis:

[0302] Record the energy consumption of each stage of the complete process; calculate the energy utilization efficiency and energy saving rate of the system; analyze the flow of energy and the cause of loss; evaluate the effect of cascade thermal energy utilization: test the actual benefits of the four-level thermal energy utilization network; evaluate the effect of waste heat recovery for preheating feed, maintaining separation devices, etc.; calculate the net energy consumption and carbon emission intensity of the overall process.

[0303] 3. Experimental Results

[0304] The energy efficiency comparison of the two process routes is shown in the following table:

[0305]

[0306] The performance data of heat recovery of phase change materials are shown in the following table:

[0307]

[0308] Schematic diagram of heat energy flow and recovery in the process Figure 2 shown.

[0309] The energy consumption comparison chart of different process stages is as follows: Figure 3 shown.

[0310] 4. Experimental Conclusion

[0311] Through comparative experiments on energy efficiency between the traditional process and this implementation method, the following conclusions are drawn:

[0312] The total energy consumption is significantly reduced: the total energy consumption of this implementation is 2.68kWh / kg product, which is 44.7% lower than the 4.85kWh / kg product of the traditional process, achieving a significant energy-saving effect.

[0313] The heat recovery rate is greatly improved: the heat recovery rate of the traditional process is only 15.3%, while this implementation method increases the heat recovery rate to 72.5% through the phase change material energy storage system, an increase of 4.7 times, and realizes the effective recovery and utilization of most of the waste heat.

[0314] Energy utilization efficiency doubled: The energy utilization efficiency of this implementation method reaches 78.6%, which is 123.3% higher than the 35.2% of the traditional process, indicating that energy transfer and conversion are more efficient.

[0315] Significant reduction in heat loss: This implementation method reduces the heat loss rate from 45.8% of the traditional process to 12.5% ​​through a high-efficiency heat pipe network and a phase change material energy storage system, reducing heat loss by 72.7%.

[0316] Phase change materials have excellent performance: Phase change materials in three different temperature zones show good thermal capacity and cycle stability. After 300 thermal cycles, the capacity retention rate is above 95%, ensuring long-term and stable thermal energy storage performance.

[0317] The energy-saving effect in the process stage is obvious: this implementation method has achieved significant energy saving in each process stage, among which the energy saving effect in the preheating stage is the most significant, with an energy saving rate of 51.9%, which is mainly due to the efficient recovery effect of the cascade heat energy utilization system.

[0318] The carbon emission intensity is greatly reduced: the carbon emission intensity of this implementation method is 1.45kgCO2 / kg product, which is 53.5% lower than the 3.12kgCO2 / kg product of the traditional process, reflecting significant environmental benefits.

[0319] The above results fully prove that this embodiment achieves efficient utilization and recovery of energy through phase change thermal energy utilization and circulation technology, which not only reduces production costs but also reduces environmental impact, providing an effective technical path for the clean production of biofuels.

[0320] Example 4

[0321] This example verifies the effects of biointerface regulation and heterogeneous catalytic technology on catalyst stability and lifespan, and compares them with traditional catalytic systems to evaluate performance changes during long-term operation.

[0322] 1. Experimental equipment and materials

[0323] Experimental equipment:

[0324] Continuous flow fixed bed reaction system (316L stainless steel, pressure resistance 5MPa, maximum temperature 450℃);

[0325] In-situ catalyst characterization device (equipped with XRD, FTIR, TEM sampling interface);

[0326] High-pressure microreactor array (16 channels of parallel reaction, programmable temperature control, pressure 0-10MPa);

[0327] Automatic sample injector and online GC-MS analysis system (Agilent 7890B / 5977A);

[0328] High-precision electronic balance (accuracy 0.0001g);

[0329] Program-controlled multi-channel catalyst evaluation device (reaction temperature 25-450℃, pressure 0-10MPa).

[0330] Experimental Materials:

[0331] Traditional catalysts:

[0332] Commercial Ni-Mo / Al2O3 catalyst (Ni 3.5wt%, Mo 12wt%, surface area 220m² / g);

[0333] Commercial Pd / C catalyst (Pd 5wt%, surface area 950m² / g).

[0334] Catalyst of this embodiment:

[0335] Biointerface-regulated Pd-Fe / SBA-15 catalyst (preparation described in Section 4.5);

[0336] Dodecyl glycoside biosurfactant (APG, purity ≥98%).

[0337] Reaction materials:

[0338] Standard biomass feedstock model mixture: a model mixture prepared from waste cooking oil and lignin (oxygen content 20±2wt%);

[0339] Sulfur, nitrogen, phosphorus and other impurity standard substances (used for catalyst poisoning testing).

[0340] Catalyst regeneration and evaluation reagents:

[0341] Hydrogen (purity 99.999%);

[0342] Nitrogen (purity 99.999%);

[0343] Oxygen (purity 99.999%);

[0344] Tetrahydrofuran (chromatographically pure, ≥99.9%);

[0345] n-Hexane (chromatographic grade, ≥99.9%).

[0346] 3. Experimental Methods

[0347] Catalyst stability evaluation experiment:

[0348] The conventional catalysts (Ni-Mo / Al2O3 and Pd / C) and the catalyst of this embodiment (biointerface regulated Pd-Fe / SBA-15) were respectively loaded into a continuous flow fixed bed reactor (catalyst loading amount 10.0±0.1 g).

[0349] Reaction conditions:

[0350] Reaction temperature: 180±2℃;

[0351] Reaction pressure: 2.5±0.1MPa;

[0352] Raw material LHSV: 0.8±0.05h -1 ;

[0353] Hydrogen to oil ratio: 600±20Nm³ / m³;

[0354] Continuous operation test: Keep the reaction conditions constant, run continuously for 800 hours, and sample and analyze the product composition and conversion rate every 4 hours.

[0355] Performance monitoring indicators:

[0356] Raw material conversion rate: calculated by GC-MS analysis of feed and product composition;

[0357] Target product selectivity: Selectivity of C8-C16 carbon chain products;

[0358] Catalyst surface area change: measured every 100 hours by BET method;

[0359] Carbon deposit amount: measured every 100 hours by TGA method.

[0360] Catalyst anti-toxicity test:

[0361] Design a phased impurity addition plan:

[0362] Stage 1 (0-200h): 50ppm sulfur (in the form of dibenzothiophene) is added to the feedstock;

[0363] Second stage (200-400h): 100ppm sulfur and 50ppm nitrogen (in the form of quinoline) are added to the feedstock;

[0364] The third stage (400-600h): 150ppm sulfur, 100ppm nitrogen and 30ppm phosphorus (in the form of triphenylphosphine) were added to the feed.

[0365] Three catalysts were tested in parallel in an array of high-pressure microreactors for their anti-poisoning properties:

[0366] The catalytic activity (characterized by the conversion rate of the model reaction) was measured every 12 h;

[0367] Catalyst samples were collected every 50 hours for surface analysis (XPS and FTIR);

[0368] The poisoning rate and activity recovery capacity were recorded.

[0369] Catalyst regeneration performance evaluation:

[0370] Catalyst regeneration solution:

[0371] Mild oxidation treatment: in a nitrogen mixed atmosphere containing 5 vol% oxygen, at 250±5℃ for 1.5h.

[0372] Reduction activation: In a pure hydrogen atmosphere, treat at 300±5℃ for 2h.

[0373] Regeneration cycle test:

[0374] The catalyst is used until its activity decreases to 65% of the initial activity and then regenerated;

[0375] Each catalyst was subjected to five complete use-regeneration cycles;

[0376] The activity recovery rate and selectivity changes after each regeneration were recorded.

[0377] Evaluation of biological interface regulation effects:

[0378] Set up a control group:

[0379] Group A: The catalyst of this embodiment does not contain any biosurfactant;

[0380] Group B: the catalyst of this embodiment is added with a conventional petroleum-based surfactant (sodium dodecyl sulfate, SDS);

[0381] Group C: The catalyst of this embodiment is added with a biosurfactant (APG).

[0382] Evaluation indicators:

[0383] Catalyst activity retention rate: the ratio of initial activity to activity after t hours;

[0384] Changes in catalyst surface wettability: measured by contact angle;

[0385] Reactant mass transfer efficiency: determined by internal diffusion control experiments;

[0386] Interfacial layer stability: Determined by dynamic light scattering and interfacial tension.

[0387] IV. Experimental Results

[0388] The comparison of stability indicators of different catalyst systems is shown in the following table:

[0389]

[0390] The comparison of the anti-poisoning performance of different catalysts is shown in the following table:

[0391]

[0392] The comparison of catalyst regeneration performance (activity recovery rate %) is shown in the following table:

[0393]

[0394] The catalyst life curve is as follows Figure 4 As shown;

[0395] The relationship between catalyst surface area change and carbon deposition amount is as follows: Figure 5 As shown;

[0396] Comparison of biological interface regulation effects Figure 6 shown.

[0397] 4. Experimental Conclusion

[0398] Through a systematic evaluation of the stability, anti-toxicity and regeneration performance of different catalyst systems, the following conclusions were drawn:

[0399] The catalyst life is significantly extended: the bio-interface-regulated Pd-Fe / SBA-15 catalyst of this embodiment still maintains 76.8% of its initial activity after 800 hours of continuous operation, and the deactivation rate is only 2.1% / 100h, which is much lower than the traditional Ni-Mo / Al2O3 catalyst (7.5% / 100h) and Pd / C catalyst (6.3% / 100h). Its catalytic half-life is 925 hours, which is 2.9 times and 2.4 times longer than that of traditional catalysts, respectively.

[0400] Greatly improved anti-poisoning performance: The catalyst of this embodiment has an activity retention rate of 68.3% in the presence of high concentration impurities (150ppm sulfur + 100ppm nitrogen + 30ppm phosphorus), which is 39.9 and 30.8 percentage points higher than the traditional Ni-Mo / Al2O3 catalyst and Pd / C catalyst, respectively, indicating that it has excellent anti-poisoning performance. This is mainly attributed to the protective layer formed by biological interface regulation, which can effectively block catalytic poisons from contacting the active center.

[0401] Excellent catalyst regeneration performance: After 5 complete use-regeneration cycles, the average activity retention rate of the catalyst in this embodiment reached 92.0%, which is much higher than that of the traditional Ni-Mo / Al2O3 catalyst (64.5%) and Pd / C catalyst (75.6%). Even after the fifth regeneration, its activity recovery rate still remained at a high level of 86.5%, indicating that the catalyst has excellent durability and regeneration ability.

[0402] The carbon deposition inhibition effect is significant: after 800 hours of continuous operation, the carbon deposition of the catalyst in this embodiment is only 7.2wt%, which is much lower than the traditional Ni-Mo / Al2O3 catalyst (31.5wt%) and Pd / C catalyst (25.7wt%). The low carbon deposition keeps the catalyst surface area retention rate at a high level (82.3%), effectively delaying the catalyst deactivation.

[0403] The key role of biointerface regulation: Experiments have shown that the addition of biosurfactants (APG) is a key factor in improving catalytic performance. Compared with no surfactant and conventional petroleum-based surfactants, biosurfactants significantly improved the catalyst activity retention rate (83.2% vs. 68.5% and 75.8%), reactant mass transfer efficiency (91.5% vs. 52.3% and 68.7%) and surface area retention rate (89.2% vs. 62.7% and 73.4%). This is mainly attributed to the orderly microenvironment formed by biosurfactants, which can promote the directional contact of reactants and the rapid separation of products, reducing side reactions and carbon deposition.

[0404] Active center protection mechanism: XPS and FTIR characterization revealed that after long-term operation of the bio-interface-regulated catalyst, the electronic state of the metal active site changed little and the coordination environment remained stable, indicating that the bio-interface layer can effectively prevent the oxidation, agglomeration and poisoning of the active center, and is an important mechanism for improving the catalyst life.

[0405] Economic benefit analysis: Based on the extended life of the catalyst and the improved regeneration ability, the use cost of the catalyst in this embodiment is about 65% lower than that of the traditional catalyst, and the catalyst-related cost per ton of product is reduced from 85-120 yuan in the traditional process to 25-40 yuan, which significantly improves the economic feasibility of the process.

[0406] In summary, this experiment verified the significant improvement effect of bio-interface regulation and heterogeneous catalysis technology on catalyst life in this embodiment. This technology not only greatly extended the service life of the catalyst, improved anti-toxicity and regeneration performance, but also achieved a more efficient and economical biofuel production process by reducing carbon deposit formation and improving mass transfer efficiency.

[0407] The above describes an embodiment of the present invention, but this embodiment is not limited to the above-mentioned specific implementation mode. The above-mentioned specific implementation mode is merely illustrative and not restrictive. Under the guidance of this embodiment, ordinary technicians in this field can also make more forms of equivalent embodiments, all of which are within the protection of this embodiment.

Claims

1. A method for preparing clean molecular recombinant biofuel, characterized in that: The following steps are involved: Step 1: Classify waste oil and lignin according to polarity characteristics to obtain components with different polarities; Step 2: Synergistically transforming components of different polarities under the action of an ultrasonic field to form a molecularly reorganized biofuel precursor; Step 3: using ethanol aqueous solution to carry out water-phase reforming reaction under the action of catalyst to produce active hydrogen species, and directional hydrogenation and stabilization of the aforementioned synergistic conversion products; Step 4: Recover the reaction heat through phase change materials and recycle it in a multi-level heat utilization network, while converting by-products into high value-added products; Step 5: Use biosurfactants and trifunctional heterogeneous catalysts to construct an interface regulation system, perform interface regulation-assisted catalysis, and improve fuel quality and stability.

2. The method for preparing a clean molecular recombinant biofuel according to claim 1, characterized in that: The specific process of raw material pretreatment and component classification in step 1 includes: Place the waste oil at 75±5℃ for 1.5±0.5 hours, remove water and solid impurities by centrifugation, and reduce the water content to below 0.1%; After immersing lignin in an ethanol / water mixed solvent, ultrasonic treatment is performed to promote the relaxation of the lignin macromolecular structure, and the cleavage rate of the sugar ether bond reaches 40-50%; The polarity of the raw material components was analyzed by near infrared spectroscopy, and the raw material components were divided into high polarity components, medium polarity components and low polarity components; The components of different polarities are separated by using an extraction system composed of three layers of solvents of different polarities to obtain concentrated solutions of components of different polarities.

3. The method for preparing a clean molecular recombinant biofuel according to claim 2, characterized in that: The specific process of the acoustic wave enhanced synergistic transformation in step 2 includes: A double-layer jacketed reactor was used, with ultrasonic transducer arrays set on the bottom and side walls, with a frequency of 28±2kHz and a power density of 300-600W / L; The low polarity component, the medium polarity component and the high polarity component are added in sequence in a step-by-step manner, and reacted under different ultrasonic power density conditions; The micro-jets and micro-high temperature points generated by ultrasonic cavitation promote the transfer of hydrogen atoms between molecules of different components, reducing the intramolecular oxygen content by 20-25%. Under the synergistic effect of ultrasound and catalyst, the selective breaking of CC bonds of macromolecules is guided, with a breaking selectivity of 75±5%, while the recombination of broken small molecule fragments is promoted, with a recombination rate of 80±5%.

4. The method for preparing a clean molecular recombinant biofuel according to claim 1, characterized in that: The specific process of in-situ hydrogen supply and activation in step 3 includes: A solution with a volume ratio of ethanol to water of 1:2 was prepared, and a reforming reaction occurred under the action of a Ni-Cu alloy nanoparticle catalyst at 230±10°C and 2.0±0.2MPa to generate hydrogen; A three-stage fixed-bed reactor with temperature zone control is used, with the upper stage used for in-situ hydrogen generation, the middle stage used for hydrogenation of synergistic conversion products, and the lower stage used for product stabilization.

5. The method for preparing a clean molecular recombinant biofuel according to claim 1, characterized in that: The specific process of phase change heat energy utilization and by-product conversion in step 4 includes: Install an aluminum alloy heat pipe network on the outer wall of the reactor, with a coverage rate of 85±5% of the reactor surface area; For different temperature ranges, sodium nitrate / potassium nitrite eutectic mixture, polyethylene glycol 6000 and metal alloy modified material composite system, and n-octadecane and expanded graphite composite material were selected; Establish a four-level thermal energy utilization network, which is used in sequence for heat supply of the synergistic conversion step, in-situ hydrogen supply, preheating of feed materials and maintaining the temperature of the separation unit; The gaseous, liquid and solid by-products are collected through a three-phase separation system and converted into high value-added products through catalytic conversion, esterification and selective hydrogenation.

6. The method for preparing a clean molecular recombinant biofuel according to claim 1, characterized in that: The specific process of biological interface regulation and heterogeneous catalysis in step 5 includes: A composite system of bio-based dodecyl glycoside and quaternary ammonium salt is used as a surfactant, wherein APG accounts for 70±2wt%, quaternary ammonium salt accounts for 25±2wt%, and polyethylene glycol accounts for 5±1wt%; Preparation of trifunctional heterogeneous catalysts, including a mesoporous SBA-15 support, a palladium-iron bimetallic nanoparticle active center, a sulfonated group acidic site, and an amino basic site; The bio-based raw materials and the interface control system were pretreated at 45±3℃ for 30±5min at a mass ratio of 1:3; Heterogeneous catalytic molecular recombination was carried out under the conditions of 180±5℃ and 2.5±0.2MPa, and the temperature, pressure and reaction time of the four reaction stages were controlled.

7. The method for preparing clean molecular recombinant biofuel according to claim 2, characterized in that: The high polarity components include phenylpropanol units and derivatives in lignin, free fatty acids and polar impurities in waste oils and fats, with a polarity index greater than 0.65; the medium polarity components include ether bond connection units in lignin, monoglycerides and diglycerides in waste oils and fats, with a polarity index of 0.35-0.65; and the low polarity components mainly include triglycerides in waste oils and fats and non-polar aromatic structural units in lignin, with a polarity index less than 0.

35.

8. The method for preparing clean molecular recombinant biofuel according to claim 3, characterized in that: The reaction medium in the sonication-enhanced synergistic conversion is ethanol, and 0.5-1.0wt% of a supported Ru / C catalyst is added; in the stepwise feeding, low-polarity components account for 45±5wt% of the total material, medium-polarity components account for 35±5wt% of the total material, and high-polarity components account for 20±5wt% of the total material.

9. The method for preparing clean molecular recombinant biofuel according to claim 4, characterized in that: The Ni-Cu alloy nanoparticle catalyst has a Ni:Cu atomic ratio of 3:1, a particle size of 10±2nm, is loaded on a γ-Al2O3 carrier, has a total metal loading of 5±0.5wt%, and is added with a K2O additive; in the zoned temperature control, the upper section temperature is 230±10°C, the middle section temperature is 180±10°C, and the lower section temperature is 150±10°C.

10. A clean molecular recombinant biofuel, characterized in that: The clean molecular recombinant biofuel is prepared by the preparation method of any one of claims 1 to 9.

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