Bagasse refining method and life cycle evaluation method thereof

Abstract

The invention discloses a life cycle evaluation method of a bagasse refining method, which is based on a bagasse refining production process system pretreated by a tribasic acid-alcohol DES system, and comprises the following steps: (1) life cycle evaluation of a DES process under a laboratory scale; (2) constructing an industrial potential model; (3) establishing a multi-dimensional system evaluation method; (4) environment monetization evaluation; and (5) constructing a sustainable evaluation integrated evaluation model. According to the life cycle evaluation method, life cycle evaluation and monetization environment accounting are combined, a multi-dimensional and data-driven environment and economic decision basis is provided for industrial application of the DES technology, and popularization of a green process and implementation of circular economy are assisted. And the process controllability and amplification feasibility are improved. And the energy and material balance modeling in the process amplification process is more accurate and controllable. And an environment-economy coupling evaluation method is constructed, so that a quantitative basis can be provided for green technology path selection and policy making.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomass refining and process evaluation, and particularly relates to a sugarcane bagasse refining method and a life cycle evaluation method thereof. BACKGROUND

[0002] Sugarcane bagasse is a byproduct generated in large quantities in the sugar industry and has a wide resource base in major sugar-producing countries such as China. As a typical lignocellulosic biomass, sugarcane bagasse has good renewability and carbon neutrality characteristics and exhibits high resource utilization potential in the bio-refining path. By converting it into platform chemicals or sugar products, it not only helps to reduce dependence on fossil resources, but also realizes waste resource utilization and promotes regional circular development. However, the complex cross-linked structure between lignin and carbohydrates in sugarcane bagasse seriously hinders the accessibility of enzymes and is the main obstacle to its efficient biological conversion. Although traditional acid / alkali pretreatment can destroy these structures to some extent, it is often accompanied by high energy consumption, generation of toxic by-products and difficulty in solvent recovery, which limits its sustainable application in industry.

[0003] In recent years, green solvent systems, especially deep eutectic solvents (DES), have become an important development direction for biomass pretreatment technology due to their low toxicity, biodegradability and component adjustability. Among them, the binary DES system composed of choline chloride and lactic acid can break the ether bonds of lignin through protonation mechanism, effectively improving the pretreatment efficiency. However, the strong acidic environment of this system may induce lignin condensation reaction, forming a more dense and hydrophobic three-dimensional structure, which seriously hinders the accessibility of cellulose and the enzymatic efficiency. To alleviate the above problems, alcohol components such as ethylene glycol are introduced to construct an acid-alcohol ternary DES system, which can protect the reaction sites of lignin through the hydroxyl group, inhibit its condensation, improve the lignin removal effect and increase the subsequent enzymatic efficiency. Although the ternary DES shows good performance under laboratory conditions, current related researches still mainly stay in the small test stage, and the focus is limited to isolated indicators such as sugar yield and lignin removal rate, lacking comprehensive evaluation of the entire process system in the technical, environmental and economic dimensions.

[0004] Life Cycle Assessment (LCA) as a standardized tool can quantify the environmental impact of products or processes throughout their life cycle. Traditional LCA is usually based on laboratory static data, which is difficult to accurately reflect the dynamic characteristics of resource input, emission changes and other dynamic characteristics during technology scaling. Multidimensional life cycle assessment methods can make more representative predictions of the environmental performance of emerging green technologies by simulating technology expansion paths. Not only can it quantify typical environmental loads such as greenhouse gas emissions, energy consumption, and water consumption, but it can also be monetized in combination with economic factors to assess resource efficiency, environmental cost, and cost performance, providing systematic decision support for the promotion of green processes. This multidimensional life cycle assessment method provides a scientific basis for comprehensive feasibility analysis of pretreatment technologies, and helps to identify technical bottlenecks, optimize design schemes and promote industrialization.

[0005] Therefore, it is urgent to establish a green pretreatment process evaluation framework for lignocellulosic waste such as sugarcane bagasse, which integrates green solvent optimization, biological conversion efficiency determination and multidimensional life cycle assessment methods, to comprehensively analyze its industrial scaling potential from the perspectives of technology, environment and economy, and to provide support paths for the transformation of green technology into actual engineering systems.

[0006] The information disclosed in this BACKGROUND section is only intended to increase an understanding of the general context in which the present application can be practiced. It is not admitted that this information constitutes prior art that is already known in the art. SUMMARY

[0007] The present application aims to provide a life cycle assessment method for a sugarcane bagasse refining method to overcome the problem that traditional LCA methods have deviations in environmental load assessment results and industrial actual conditions, or fail to quantify economic impacts simultaneously, and cannot support the comprehensive decision-making needs in the process of policy-making or industrialization. The purpose of the life cycle assessment method of the present application is to improve process controllability and scaling feasibility, and to provide quantitative basis for green technology path selection and policy-making.

[0008] Another object of the present application is to provide a sugarcane bagasse refining method to improve the pretreatment efficiency of sugarcane bagasse and the subsequent enzymatic sugar yield.

[0009] To achieve the above-mentioned objects, the present application provides a life cycle assessment method for a sugarcane bagasse refining method based on a ternary acid-alcohol DES system pretreatment of sugarcane bagasse refining production process system, comprising the following steps:

[0010] (1) Life cycle assessment of DES process at laboratory scale: define the target and scope, conduct life cycle inventory analysis and life cycle environmental impact assessment, and build a full life cycle sustainability evaluation index system for DES production process system;

[0011] (2) Construction of industrialization potential model: based on the completion of life cycle inventory analysis at laboratory scale, sort out the key process parameters and material and energy consumption data, and preliminarily construct the corresponding industrial data inventory structure to provide the original input framework for industrial process modeling;

[0012] (3) Establish a multi-dimensional system evaluation method: build a complete life cycle assessment model, select environmental impact indicators for multi-dimensional quantitative evaluation, and then integrate and evaluate the multi-dimensional environmental impact results;

[0013] (4) Environmental monetization assessment;

[0014] (5) Construction of sustainability evaluation integrated evaluation model.

[0015] Preferably, in the above technical solution, step (1) defines the target and scope, including:

[0016] 1) Evaluation target: quantifying the environmental impact of solvent DES preparation and its use in biomass pretreatment process, and evaluating the environmental impact of the process preparation of the solvent;

[0017] 2) Functional unit: obtain 1 kg of glucose;

[0018] 3) System boundary, including DES raw material acquisition and transportation, DES synthesis process, biomass pretreatment process and waste liquid treatment;

[0019] 4) Assumptions and limitations: including the use of analytical pure reagents in the laboratory; assuming that the energy is standard grid electricity, using the local national average power structure; if there is no specific waste liquid treatment data, refer to the literature or use the disposal in the hazardous waste system simulation.

[0020] Preferably, in the above technical solution, step (1) life cycle inventory analysis includes:

[0021] 1) Data collection: the collected data includes one or more of the following data, DES raw material consumption, synthesis temperature and time, stirring power, biomass feed quantity, pretreatment temperature / time, separation method and energy consumption, equipment power consumption, cooling water or other auxiliary product use, chemical reagent environmental data;

[0022] 2) Unit process modeling: establish independent process units for each process of DES synthesis, biomass pretreatment and solid-liquid separation, and conduct LCA modeling.

[0023] Preferably, in the above technical solution, the step (2) industrialization potential model construction comprises:

[0024] 1) Data amplification and conversion method: reasonably extend and convert the laboratory data, including linear or nonlinear extrapolation of material consumption through material and energy conservation principles; adjusting the energy consumption of stirring, heating and distillation unit operations according to the performance parameters of typical industrial equipment;

[0025] 2) Process integration and system modeling: integrating the amplified unit operations into a complete industrial process, covering the core steps of DES synthesis, biomass pretreatment, material separation and solvent recovery; combining laboratory data acquisition, industrial process design guidelines and life cycle modeling requirements, completing the systematic connection and material flow mapping of multi-unit process.

[0026] 3) Construction of energy and material balance model of amplification process: according to the actual production requirements of industrial scale, set up industrial amplification unit, combined with the ratio parameters used in the experiment, systemically construct the material and energy balance model of the whole process of DES pretreatment process;

[0027] 4) Parameterized modeling of solvent recovery subsystem: for the DES recycling process, select representative industrial condensing and distilling equipment, collect key parameters such as power / thermal energy consumption and solvent recovery rate, establish an independent database for solvent recovery process, which is part of the life cycle system model, included in the system boundary, and used to quantitatively evaluate the mitigation effect of solvent regeneration on overall environmental load.

[0028] Preferably, in the above technical solution, the method of step 1) reasonably extending and converting laboratory data comprises approximation method, engineering analogy method, process simulation method and empirical scaling method.

[0029] Preferably, in the above technical solution, step 3) energy and material balance model of amplification process covers: reactant and solvent material consumption; energy consumption of heating, stirring, distillation and drying in operation engineering; contribution of heat recovery, waste heat utilization and solvent circulation to system energy efficiency; wherein the energy consumption of each step is estimated by multiplying the equipment power by time, and the heat consumption is calculated and checked by process temperature and heat transfer coefficient.

[0030] Preferably, in the above technical solution, the environmental impact indicators for environmental impact assessment include: global warming potential, water resource consumption, human toxicity, ecological toxicity, acidification potential, eutrophication and cumulative energy consumption;

[0031] Global warming potential GWP

[0032] The relative contribution of a unit mass of greenhouse gas to climate warming within a certain time scale is measured, with the unit being ; Formula: ;

[0033] where: Ei is the emission of the i-th greenhouse gas, in kg; GWP i , 100 is the global warming potential coefficient of the gas at a time scale of 100 years, for example = 1, = 27.2, = 273;

[0034] TAP

[0035] measures the potential impact of acidic substances, such as , , on soil systems, in kg H+eq ; formula: ;

[0036] where: E k : emission of the k-th acidic precursor; APFk: its acidification potential factor, for example: =1; =0.7; =1.88;

[0037] HTP

[0038] measures the potential harm to human health caused by toxic substances, in kg 1,4-DCB -eq , p-dichlorobenzene equivalent; formula: ;

[0039] where: E n : emission of the n-th toxic substance into air, water or soil; : human toxicity potential factor;

[0040] WDP

[0041] measures the total freshwater use in a unit process, in m ; it can be further weighted using a water scarcity weight; formula: ;

[0042] where: W p : freshwater use (m 3 ) of the p-th process; WS p : water scarcity coefficient of the region;

[0043] ETP

[0044] formula: ;

[0045] where mj is the emission and EFj is the ecotoxicity factor;

[0046] Eutrophication EP

[0047] Equation: ;

[0048] Where: mj: the emission of pollutant j (unit: kg); EPj: the eutrophication equivalent factor of the pollutant, unit: ; EP: the total eutrophication potential, unit: ;

[0049] The integrated assessment of multi-dimensional environmental impact results includes selecting a unified functional unit FU, processing 1 kg of sugarcane residue; and normalizing each environmental impact index according to the regional or global average annual emission per capita: ;

[0050] Where, imapct i refers to the i th environmental impact category, that is, a specific environmental impact dimension being evaluated, such as the global global warming potential, water resource consumption, human toxicity, ecological toxicity, acidification potential, eutrophication, and cumulative energy consumption index; Reference i represents the total burden per person per year in the i th category on a global or regional average; Normalized i : i indicates the proportion of the total annual environmental burden of the system in the category.

[0051] Preferably, in the above technical solution, step (4) environmental monetization assessment is: on the basis of standardized LCA results, a monetization factor system is introduced to convert each environmental load into corresponding economic cost, quantify the environmental externality of green process, and provide comparable monetary units for environmental and economic coupling analysis; each index is converted into RMB unit, and social carbon price, water price, and toxicity burden cost are commonly used; Equation: ;

[0052] Where: i represents the i th environmental impact dimension, such as global warming GWP, acidification TAP, eutrophication EP, and other indexes; Normalized i represents the normalized result of the i th category, indicating its proportion relative to the reference burden, unit: dimensionless; W i represents the weighting coefficient of the i th category, reflecting its importance / priority in the total environmental burden, unit: dimensionless or monetization; total score represents the final comprehensive environmental impact score, a single value of a dimensionless or weighted unit, representing the total amount of overall environmental burden.

[0053] Preferably, in the technical scheme, the step (5) of constructing the sustainability evaluation integrated evaluation model comprises: combining raw material consumption, energy intensity, pollutant emission, solvent recovery efficiency and environmental cost indicators to establish a process-resource-environment-economy integrated evaluation framework to form a multi-dimensional analysis result of the pretreatment path sustainability and industrial expansion.

[0054] A sugar cane bagasse refining method for the above-mentioned life cycle assessment; the sugar cane bagasse refining method comprises the following steps:

[0055] (1) washing, drying, crushing and sieving the sugar cane bagasse;

[0056] (2) mixing and stirring choline chloride as a hydrogen bond acceptor and ethylene glycol and lactic acid as hydrogen bond donors to obtain a ternary eutectic solvent;

[0057] (3) mixing and reacting the ternary eutectic solvent and the pretreated sugar cane bagasse, after the reaction, washing, suction filtering and drying to obtain the sugar cane bagasse treated by the DES.

[0058] Preferably, in the technical scheme, the sugar cane bagasse refining method, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor in step (2) is 1:2-1:10, and the temperature of the mixing reaction is 70-90 DEG C; wherein the molar ratio of the mixed ethylene glycol and lactic acid in the hydrogen bond donor is 1:2-1:5;

[0059] In step (3), the solid-liquid ratio of the ternary eutectic solvent and the pretreated sugar cane is 1:10-1:15, and the reaction is carried out at 100-150 DEG C for 1-3 h.

[0060] Compared with the prior art, the present application has the following beneficial effects:

[0061] (1) The sugar cane bagasse refining method of the present application, by constructing a ternary eutectic solvent (DES) system, i.e. designing a ternary acid-alcohol DES system, introducing an alcohol component with hydroxyl protection effect, effectively inhibiting lignin condensation reaction, improving cellulose accessibility, thereby realizing glucose enzymatic hydrolysis yield breakthrough 95%, having significant advantages in improving sugar yield and resource conversion efficiency. The DES system constructed in the refining method of the present application, by regulating the components and acid-base environment, effectively improves the defects of traditional DES in the pretreatment process, i.e. easily causing lignin condensation and limiting enzymatic hydrolysis, thereby significantly improving the accessibility of enzymes and sugar yield, promoting the efficient utilization and resource conversion of waste biomass such as sugar cane bagasse.

[0062] (2) The life cycle assessment method of the sugarcane bagasse refining method of the present application covers key links such as raw material traceability, energy consumption accounting, solvent recovery and environmental load allocation, and can be used for quantitative analysis of resource efficiency and environmental impact of each unit operation in the DES synthesis and pretreatment process. The method combines life cycle assessment and monetized environmental accounting to provide multi-dimensional, data-driven environmental and economic decision-making basis for the industrial application of DES technology, and helps the promotion of green process and the implementation of circular economy.

[0063] (3) The life cycle assessment method of the present application builds an industrial energy-material balance model based on a 100 L reaction volume as a basic unit, combines the actual energy consumption calculation methods of unit operations such as stirring, heating, distillation and drying, and introduces solvent recycling and heat recovery strategies to realize accurate scaling from experimental data to pilot data, and improve process controllability and scaling feasibility. That is, the energy and material balance modeling in the process scaling is more accurate and controllable.

[0064] (4) The life cycle assessment method of the present application builds a multi-dimensional environmental impact assessment and monetization model to support sustainable optimization decision-making. According to the ISO 14040 / 44 standard, a multi-index evaluation system including global warming potential (GWP), water consumption (WDP), human toxicity (HTP), ecological toxicity (ETP), acidification potential (TAP), and eutrophication (EP) is systematically introduced, and further combined with environmental monetization factors such as social carbon price, water price, and toxicity burden to build an environment-economy coupled assessment method, which can provide quantitative basis for green technology path selection and policy making. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 is a sugar enzymatic hydrolysis efficiency diagram of pretreated sugarcane bagasse and untreated sugarcane bagasse according to the sugarcane bagasse refining method of the present application.

[0066] Figure 2 is a normalized environmental assessment result diagram based on the life cycle assessment method of the bio-refining process of the present application.

[0067] Figure 3 is a normalized environmental assessment result diagram based on the life cycle assessment method of the bio-refining process of the present application. DETAILED DESCRIPTION

[0068] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present application is not limited by the specific embodiments.

[0069] Unless otherwise expressly provided, throughout the specification and claims, the term "comprise" or variations such as "comprises" or "comprising" will be understood to imply the inclusion of a stated element or group of elements but not the exclusion of any other element or group of elements.

[0070] The instruments and reagents used in the following examples are commercially available. Example

[0071] The process steps of pretreating bagasse by DES, i.e. the bagasse refining method, include the following steps:

[0072] (1) The bagasse was pretreated, i.e. washed, dried, and crushed and then passed through a 60-mesh sieve. The main components of the bagasse were determined as follows: cellulose content 40.92%, hemicellulose content 24.72%, acid-soluble lignin content 23.13%, acid-insoluble lignin content 2.63%, and ash content 0.07%.

[0073] (2) Then, DES was prepared by mixing choline chloride as the hydrogen bond acceptor and ethylene glycol and lactic acid as the hydrogen bond donors. The molar ratio of the hydrogen bond acceptor to the hydrogen bond donor was controlled to be 1:2, and the molar ratio of ethylene glycol to lactic acid in the hydrogen bond donor was 1:2. After mixing, the mixture was placed in a beaker and placed on a double-digital constant-temperature magnetic stirrer. The mixture was stirred at 80°C for one hour until the DES system became a transparent solution, and the final ternary DES was obtained.

[0074] (3) The pretreated bagasse was pretreated using the ternary DES prepared above. The solid-liquid ratio of the reaction was set to 1:10, and the pretreatment was performed at 150°C for 3 h. After the reaction was completed, 60 mL of anhydrous ethanol was used to rinse the DES and poured into a Buchner funnel for suction filtration. When the DES was completely suction-filtered, it was poured into a 500 mL beaker, and anhydrous ethanol was added to 400 mL and left to stand. The suction filtration was continued, and the qualitative filter paper with solid residues was taken out and placed in a petri dish and dried in an oven at 105°C until the water was removed. The dried bagasse was crushed using an electric plant fiber crusher and stored in a bag. Example

[0075] The enzymatic hydrolysis experiment of the bagasse was performed according to the following steps:

[0076] (1) The preparation of sodium citrate buffer: 2.101 g of citric acid and 2.941 g of trisodium citrate were dissolved in a small beaker, respectively, and then poured into a 100 mL volumetric flask, respectively, and made up to volume. After preparation twice, 165.6 mL of citric acid solution and 194.4 mL of trisodium citrate solution and 360 mL of deionized water were taken by a pipette and placed in a 1000 mL blue cap bottle to prepare a sodium citrate buffer with a pH value of 4.8.

[0077] (2) 0.5 g of pretreated bagasse was added to a 50 mL conical flask, and two parallel experiments were set up for each sample. The cellulase was added at a loading of 20 FPU / g, and the conical flask was placed in a beaker containing a sodium citrate buffer solution with a pH value of 4.8. After stirring evenly, the solution was made up to volume with a 250 mL volumetric flask. 25 mL of the prepared solution was added to the conical flask, which was placed in a constant temperature shaker at 50°C for incubation.

[0078] (3) Sample 1.5 mL at appropriate intervals (3 h, 6 h, 9 h, 12 h, 24 h, 36 h, 48 h, 72 h), centrifuge at 4°C for 10 min in a high-speed refrigerated centrifuge. Take 1 mL of supernatant, filter with a 0.22 μm membrane, and determine the glucose content in each group of samples by high performance liquid chromatography. Finally, calculate the corresponding enzymatic hydrolysis efficiency. The enzymatic hydrolysis efficiency of sugarcane bagasse pretreated by the sugarcane bagasse refining method and untreated sugarcane bagasse Figure 1 is shown. Example

[0079] A life cycle assessment method for a sugarcane bagasse refining method based on a ternary acid-alcohol DES system pretreatment of sugarcane bagasse refining production process system. It includes the following steps:

[0080] I. Life cycle assessment of DES process at laboratory scale

[0081] Define the target and scope, conduct life cycle inventory analysis and life cycle environmental impact assessment, and build a full life cycle sustainability evaluation index system for the DES production process system. The normalized environmental assessment results of the life cycle evaluation method at laboratory scale are shown in Figure 2 .

[0082] 1. Target and scope definition

[0083] (1) Evaluation target: Quantify the environmental impact of green solvent DES preparation and its use in biomass pretreatment; evaluate the environmental impact of the process preparation of the green solvent; and provide environmental friendliness reference for subsequent industrial scale-up.

[0084] (2) Functional unit: Obtain 1 kg of glucose.

[0085] (3) System boundary: including DES feedstock acquisition and transportation, DES synthesis process, biomass pretreatment process and waste liquid treatment; excluding downstream enzymatic hydrolysis, fermentation, product purification, etc. which are not the research objectives.

[0086] (4) Assumptions and limitations: including the use of analytical grade reagents in the laboratory; assuming that the energy is standard grid electricity, using the local national average electricity structure; if there is no specific waste liquid treatment data, refer to the literature or use "disposal in hazardous waste system" simulation.

[0087] 2. Life cycle inventory analysis

[0088] (1) Data collection, as shown in Table 1.

[0089] Table 1 Data collection

[0090]

[0091] (2) Unit process modeling: each process (DES synthesis, biomass pretreatment, solid-liquid separation) establishes an independent process unit for LCA modeling.

[0092] (3) Life cycle impact assessment, select representative impact categories, as shown in Table 2.

[0093] Table 2

[0094]

[0095] (4) Construct the green solvent DES production process system of the whole life cycle sustainability evaluation index system.

[0096] II. Construction of industrialization potential model

[0097] Based on the completion of the life cycle inventory analysis at the laboratory scale, the key process parameters and material and energy consumption data are sorted out, and the corresponding industrial data inventory structure is preliminarily constructed to provide the original input framework for industrial process modeling. The normalized environmental assessment results of life cycle assessment at the industrial scale are shown in Table 3. Figure 3

[0098] (1) Data scaling and conversion method: combined with the scaling characteristics and process complexity, approximate method, engineering analogy method, process simulation method, empirical scaling method, etc. are used to reasonably expand and convert the laboratory data. Among them, the material and energy consumption is linearly or nonlinearly extrapolated through the conservation of mass and energy; the energy consumption of stirring, heating and distillation unit operations is adjusted according to the performance parameters of typical industrial equipment.

[0099] ​(2) Process integration and system modeling: The scaled-up unit operations are integrated into a complete industrial process, covering DES synthesis, biomass pretreatment, material separation and solvent recovery, etc. The simulation process combines laboratory data collection, industrial process design guidelines, and life cycle modeling requirements to complete the systematic connection and material flow mapping of multi-unit processes.

[0100] (3) Construction of energy and material balance models for scaled-up processes: Based on the actual production requirements of current industrial scale, a 100 L reaction volume is set as the basis for industrial scaling of the unit, and combined with the experimental ratio parameters, a material and energy balance model for the entire DES pretreatment process is systematically constructed.

[0101] This model covers: material consumption of reactants, solvents, etc.; energy consumption of main operation processes (heating, stirring, distillation, drying, etc.); the contribution of heat recovery, waste heat utilization and solvent circulation to the improvement of system energy efficiency.

[0102] The energy consumption of each step is estimated by multiplying the equipment power by the time, and the heat consumption is calculated and checked by the process temperature and heat transfer coefficient.

[0103] (4) Parameterized modeling of solvent recovery subsystem: For the DES recycling process, representative industrial condensing and distillation equipment is selected, and key parameters such as energy consumption (electricity / heat) and solvent recovery rate are collected to establish an independent database for the solvent recovery process. This database is part of the life cycle system model, included in the system boundary, and used to quantitatively evaluate the mitigation effect of solvent regeneration on the overall environmental load.

[0104] Three, establish a multi-dimensional system evaluation method

[0105] Construct a complete life cycle assessment model, select environmental impact indicators for multi-dimensional quantitative evaluation, and integrate and evaluate the multi-dimensional environmental impact results.

[0106] (1) Select environmental impact indicators for multi-dimensional quantitative evaluation: Based on ISO 14040 / 44 standards, a complete life cycle assessment model is constructed, and typical environmental impact indicators are selected for multi-dimensional quantitative evaluation to reflect the advantages and disadvantages of the technical scheme in the environmental dimension. Among them, the environmental impact indicators include global warming potential, water resource consumption, human toxicity, ecological toxicity, acidification potential, eutrophication, and cumulative energy consumption, etc.

[0107] Global Warming Potential (GWP)

[0108] Measures the relative contribution of a unit mass of greenhouse gas to climate warming over a certain time scale, with a unit of ; Formula: ;

[0109] where: Ei is the emission of the ith greenhouse gas, in kg; GWP i , 100 is the global warming potential coefficient of the gas at a 100-year time scale, for example = 1, = 27.2, = 273.

[0110] Terrestrial Acidification Potential (TAP)

[0111] Measures the potential impact of acidic substances, such as , , on soil systems, in ; formula: ;

[0112] where: E k : the emission of the kth acidic precursor; APFk: its acidification potential factor, for example = 1; = 0.7; = 1.88.

[0113] Human Toxicity Potential (HTP)

[0114] Measures the potential harm to human health caused by toxic substances, in , dichlorobenzene equivalents; formula: ;

[0115] where: E n : the emission of the nth toxic substance to air, water or soil; : the human toxicity potential factor.

[0116] Water Scarcity / Consumption (WDP)

[0117] Measures the total freshwater use in a unit process, in ; it can be further weighted using a water scarcity weight; formula: ;

[0118] where: W p : the freshwater use (m 3 ) of the pth process; : the water scarcity factor of the region.

[0119] Ecotoxicity Potential (ETP)

[0120] Equation: ;

[0121] Where mj is the emission, and EFj is the ecotoxicity factor.

[0122] Eutrophication Potential (EP)

[0123] Equation: ;

[0124] Where: mj: the emission of pollutant j (unit: kg); EPj: the eutrophication equivalent factor of the pollutant, unit: ; EP: the total eutrophication potential, unit: .

[0125] (2) Multi-dimensional environmental impact result integration assessment, select a unified functional unit FU, process 1 kg of sugarcane residue; normalize each environmental impact index according to regional or global average per capita annual emission: ;

[0126] Where, imapct i is the i th environmental impact category, that is, a specific environmental impact dimension being evaluated, such as the global global warming potential, water resource consumption, human toxicity, ecological toxicity, acidification potential, eutrophication, and cumulative energy consumption index; Reference i represents the total burden per person per year in the i th category on a global or regional average; Normalized i : i indicates the proportion of the total annual environmental burden of the system in the category.

[0127] Four, environmental monetization assessment

[0128] On the basis of standardized LCA results, introduce a monetization factor system to convert each environmental load into corresponding economic cost, quantify the environmental externality of green process, and provide comparable monetary units for environmental and economic coupling analysis; convert each index into RMB unit, commonly use social carbon price, water price, and toxicity burden cost; Equation: ;

[0129] Where: i represents the i th environmental impact dimension, such as global warming GWP, acidification TAP, eutrophication EP, etc.; Normalized i represents the normalized result of the i th category, indicating its proportion relative to the reference burden, unit: dimensionless; W iWi represents the weighting coefficient of the ith category, reflecting its importance / priority in the total environmental burden, unit: dimensionless or monetization; total score represents the final comprehensive environmental impact score, a single value of dimensionless or weighted unit, representing the total amount of overall environmental burden.

[0130] V. Construction of the sustainability assessment integrated assessment model

[0131] Combining raw material consumption, energy intensity, pollutant emission, solvent recovery efficiency and environmental cost indicators, an integrated evaluation framework of "process-resource-environment-economy" is established, forming a multi-dimensional analysis result of the sustainability and industrial expansion of the pretreatment path.

[0132] The foregoing description of specific exemplary embodiments of the application is intended to be illustrative only and is not intended to limit the application to the precise forms described. Many modifications and variations are possible in light of the above teachings without departing from the spirit or essential characteristics of the application. The exemplary embodiments are chosen and described in order to explain the principles of the application and its practical application to thereby enable others skilled in the art to best utilize the application and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the application be defined by the claims and their equivalents.

Claims

1. A method for life cycle assessment of a bagasse refining process, characterized by, A sugarcane bagasse refining production process system based on a ternary acid-alcohol DES system pretreatment, comprising the following steps: (1) Life cycle assessment of the DES process at the laboratory scale: define the target and scope, conduct life cycle inventory analysis and life cycle environmental impact assessment, and construct a full life cycle sustainability evaluation index system for the DES production process system; (2) Construction of an industrialization potential model: based on the completion of the life cycle inventory analysis at the laboratory scale, sort out the key process parameters and material and energy consumption data, and preliminarily construct the corresponding industrial data inventory structure to provide the original input framework for industrial process modeling; (3) Establish a multi-dimensional system evaluation method: build a complete life cycle assessment model, select environmental impact indicators for multi-dimensional quantitative evaluation, and then integrate and evaluate the multi-dimensional environmental impact results; (4) Environmental monetization assessment; (5) Construction of an integrated sustainability assessment model.

2. The method for life cycle assessment of a bagasse refining method according to claim 1, characterized in that, Step (1) defines the target and scope, including: 1) Evaluation target: quantify the environmental impact of solvent DES preparation and its use in biomass pretreatment, and evaluate the environmental impact of the process preparation of the solvent; 2) Functional unit: obtain 1 kg of glucose; 3) System boundary, including the acquisition and transportation of DES raw materials, the synthesis process of DES, the biomass pretreatment process and waste liquid treatment; 4) Assumptions and limitations: including the use of analytical grade reagents in the laboratory; assuming that the energy is standard grid electricity, using the local national average electricity structure; if there is no specific waste liquid treatment data, refer to the literature or use the disposal in the hazardous waste system simulation.

3. The method for life cycle assessment of a bagasse refining method according to claim 1, characterized in that, Step (1) life cycle inventory analysis includes: 1) Data collection: the collected data includes one or more of the following data, DES raw material consumption, synthesis temperature and time, stirring power, biomass feed quantity, pretreatment temperature / time, separation method and energy consumption, equipment power consumption, cooling water or other auxiliary product use, chemical reagent environmental data; 2) Unit process modeling: each process of DES synthesis, biomass pretreatment and solid-liquid separation is established as an independent process unit for LCA modeling.

4. The method for life cycle assessment of the bagasse refining method according to claim 1, characterized by, Step (2) construction of an industrialization potential model includes: 1) Data scaling and conversion method: reasonably scale and convert the laboratory data, including linear or nonlinear extrapolation of material consumption based on the principle of conservation of mass and energy; adjust the energy consumption of stirring, heating and distillation unit operations according to the performance parameters of typical industrial equipment; 2) Process integration and system modeling: integrate the scaled unit operations into a complete industrial process, covering the core steps of DES synthesis, biomass pretreatment, material separation and solvent recovery; simulate the process by combining laboratory data collection, industrial process design criteria and life cycle modeling requirements, and complete the systematic connection and material flow mapping of multiple unit processes; 3) Construction of energy and material balance model for scaling process: according to the actual production requirements of industrial scale, set up industrial scaling units, combine the ratio parameters used in the experiment, and systematically construct the material and energy balance model for the whole process of DES pretreatment process; 4) Solvent recovery subsystem parameterization modeling: For the DES recycling process, representative industrial condensation and distillation equipment is selected, and key parameters such as power / thermal energy consumption and solvent recovery rate are collected to establish an independent database for the solvent recovery process. This database is part of the life cycle system model, included in the system boundary, and used to quantitatively assess the mitigation effect of solvent regeneration on overall environmental load.

5. The method for life cycle assessment of a bagasse refining method according to claim 4, characterized in that, Step 1) The method for reasonably extending and converting laboratory data includes approximation method, engineering analogy method, process simulation method, and empirical scaling method; And / or step 3) scale-up process energy and material balance model covers: reactant and solvent material consumption; energy consumption of heating, stirring, distillation, and drying in operation; contribution of heat recovery, waste heat utilization, and solvent circulation to system energy efficiency; wherein the energy consumption of each step is estimated by multiplying the equipment power by the time, and the heat consumption is calculated and checked by the process temperature and heat transfer coefficient.

6. The method for life cycle assessment of the bagasse refining method according to claim 1, characterized by, The environmental impact indicators for environmental impact assessment include: global warming potential, water resource consumption, human toxicity, ecological toxicity, acidification potential, eutrophication, and cumulative energy consumption; Global warming potential GWP A measure of the relative contribution of a unit mass of a greenhouse gas to climate warming over a certain timescale, with units of ; formula: ; wherein: Ei is the emission of the ith greenhouse gas, in kg; 100 is the global warming potential coefficient of the gas on a 100-year time scale, for example = 1, = 27.2, = 273; Acidification potential TAP measuring acidic substances, such as , , potential impact on soil systems, in units of ; formula: ; wherein: E k : the emission of the kth acid precursor; APFk: its acid potential factor, as defined by: = 1; = 0.7; = 1.88; Human toxicity HTP The potential of a toxic substance to cause harm to human health, measured in units of , equivalent to dichlorobenzene; formula: ; wherein: E n : the amount of the nth toxic substance emitted into the air, water, or soil; : the human toxicity potential factor; Water resource consumption WDP Total fresh water usage in the unit process, in units of ; can be further weighted using water scarcity weights; formula: ; Wherein: W p : Freshwater usage of the pth process (m 3 ); WS p : Water scarcity coefficient of the region; Ecological toxicity ETP Equation: ; Wherein, mj is the emission, and EFj is the ecological toxicity factor; Eutrophication EP Equation: ; Wherein: mj: the emission amount of pollutant j (unit: kg); EPj: the eutrophication equivalent factor of the pollutant, unit: ; EP: the total eutrophication potential, unit: ; The integrated assessment of the results of the multi-dimensional environmental impact includes selecting a uniform functional unit FU, which is 1 kg of bagasse; and normalizing each environmental impact indicator according to the regional or global average annual emissions per capita: ; where imapct i is the i-th environmental impact category, i.e. a specific environmental impact dimension under evaluation, such as the global warming potential, water resource consumption, human toxicity, ecotoxicity, acidification potential, eutrophication, cumulative energy consumption indicators mentioned above; Reference i represents the total burden per person per year in the world or in a region under the category i; Normalized i : i represents the proportion of the total annual environmental burden of the system under the category.

7. The method for life cycle assessment of a bagasse refining process according to claim 6, characterized in that, Step (4) environmental monetization evaluation: On the basis of standardized LCA results, introduce a monetization factor system to convert each environmental load into corresponding economic cost, quantify the environmental externality of green process, and provide comparable monetary units for environmental and economic coupling analysis; convert each index into RMB unit, commonly use social carbon price, water price, and toxicity burden cost; formula: ; where: i represents the i-th environmental impact dimension, such as: global warming GWP, acidification TAP, eutrophication EP, etc. indicators; Normalized i represents the normalized result of the i-th category, representing its proportion relative to the reference burden, unit: dimensionless; W i represents the weighting coefficient of the i-th category, reflecting its importance / priority in the total environmental burden, unit: dimensionless or monetization; total score represents the final comprehensive environmental impact score, a single value of a dimensionless or weighted unit, representing the total amount of overall environmental burden.

8. The method for life cycle assessment of the bagasse refining method according to claim 1, characterized by, Step (5) Construct an integrated assessment model for sustainability assessment, including: combining raw material consumption, energy intensity, pollutant emission, solvent recovery efficiency, and environmental cost indicators to establish a process-resource-environment-economy integrated evaluation framework, and form a multi-dimensional analysis result of the sustainability and industrial expansion of the pretreatment path.

9. A method of refining bagasse, characterized by, The method for refining sugar cane bagasse according to claim 1 comprises the following steps: (1) washing, drying, crushing and sieving the sugar cane bagasse; (2) mixing and stirring choline chloride as a hydrogen bond acceptor, ethylene glycol and lactic acid as hydrogen bond donors to obtain a ternary eutectic solvent; (3) mixing and reacting the ternary eutectic solvent with the pretreated sugar cane bagasse, then rinsing, filtering and drying to obtain the sugar cane bagasse treated by DES.

10. The bagasse refining method according to claim 9, characterized in that, Step (2) The molar ratio of hydrogen bond acceptor to hydrogen bond donor is 1:2-1:10, and the temperature of the mixed reaction is 70-90 ℃; wherein the molar ratio of ethylene glycol and lactic acid mixed in the hydrogen bond donor is 1:2-1:5; Step (3) The solid-liquid ratio of the acid eutectic solvent DES and the pretreated sugar cane is 1:10-1:15, and the reaction is carried out at 100-150 ℃ for 1-3 h.

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