Modularized deconstruction carbon footprint evaluation method in complex petrochemical process

Abstract

The invention discloses a modular deconstruction carbon footprint evaluation method for a complex petrochemical process, and solves the problem of inaccurate carbon footprint accounting caused by substance backflow cross cyclic utilization in the petrochemical process. The method comprises the steps that a target product technological process is deconstructed to form a plurality of modules; establishing a module independent carbon footprint model according to module input and output; establishing a module accumulated carbon footprint model according to the input intermediate product carbon footprint and the independent carbon footprint model, wherein the intermediate product carbon footprint is obtained according to the mass fraction of the intermediate product carbon footprint in the module and the accumulated carbon footprint of the module; and calculating the accumulated carbon footprints of the modules by combining the accumulated carbon footprint models of all the modules, and carrying out result analysis. According to the method, the complex flow relation of materials and energy among all production devices in the petrochemical technology is considered, and the problems that comprehensive and accurate actual production data is difficult to obtain in the prior art, and due to insufficient support of a background database, an accounting result cannot accurately reflect the current situation of the current product carbon footprint are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon footprint, in particular to a complex petrochemical process modularization deconstruction carbon footprint evaluation method. BACKGROUND

[0002] The petrochemical industry is an important department of greenhouse gas emission. Due to the complexity of the production process, the involvement of multiple production links and the diversity of production processes, the production process has high integration, the materials and energy are highly coupled between multiple devices and units, which increases the difficulty of carbon emission accounting and data acquisition. The raw materials and products of each production link are complex, and there are many material reflux and recycling between devices, which requires considering the allocation of carbon emissions among multiple products. The petrochemical process also has obvious spatio-temporal heterogeneity, and different production cycles, processes, devices and geographical locations will also lead to dynamic changes in carbon emission levels. These factors make it difficult to account for carbon emissions in the petrochemical industry.

[0003] Since the traditional life cycle assessment method regards the entire production process of the product as a black box process, it does not consider the complex flow relationship of materials and energy between production devices in the process, especially the material reflux, cross recycling and multi-product carbon footprint allocation in the complex production chain. At the same time, it is also difficult to obtain comprehensive and accurate actual production data, and the background database is not sufficient, which leads to the fact that the accounting result cannot accurately reflect the current product carbon footprint status. Therefore, it is urgent to propose a product carbon footprint accounting method suitable for the characteristics of the petrochemical industry to solve the problems of complex process, material reflux, cross recycling and multi-product carbon footprint allocation. For example, patent No. 201611019876.6, a method for measuring the carbon footprint of petrochemical products, calculates the carbon footprint of petrochemical products in the whole life cycle, mainly according to the carbon emissions of crude oil extraction, crude oil transportation, petrochemical product emission process, product sales process, and petrochemical product use and disposal process. This patent does not consider the material reflux, cross recycling and multi-product carbon footprint allocation between devices, which leads to inaccurate carbon footprint accounting of the production process. SUMMARY

[0004] The present application mainly solves the problem of inaccurate carbon footprint accounting caused by complex petrochemical process, material reflux, cross recycling, and provides a complex petrochemical process modularization deconstruction carbon footprint evaluation method.

[0005] The above technical problems of the present application are mainly solved by the following technical scheme: a complex petrochemical process modularization deconstruction carbon footprint evaluation method, comprising the following steps: determining a target product, and deconstructing the process flow of the target product to form multiple modules; establishing a module independent carbon footprint model according to the input and output of the module; The cumulative carbon footprint model is established according to the input intermediate product carbon footprint and the independent carbon footprint model, and the intermediate product carbon footprint is obtained according to the mass fraction thereof in the module and the cumulative carbon footprint of the module. The cumulative carbon footprint of all modules is calculated by combining the cumulative carbon footprint models of all modules. The result analysis is performed according to the module carbon footprint.

[0006] The present application performs module decomposition on the petrochemical process, constructs a carbon footprint model according to the numerous material reflux and recycling involved in each module, and jointly calculates the carbon footprint of each module according to the module carbon footprint model, so as to ensure that the carbon footprint accounting has high accuracy and comparability. The present application considers the complex flow relationship of materials and energy between various production devices in the petrochemical process, and also solves the problem that the existing method is difficult to obtain comprehensive and accurate actual production data, and the background database is insufficient, resulting in that the accounting result cannot accurately reflect the current product carbon footprint. The present application realizes accurate control of carbon footprint accounting, determines the emission sources of different production links and intermediate products through the involvement of the carbon footprint of each module, reduces the unclear or missing emission situation of the life cycle boundary in the existing method, and ensures the comprehensive coverage of carbon emission sources. The collection and processing method of carbon footprint data is optimized, the relationship between the emission sources and the emission categories is systematized through the integration of modularization and flow graph, the efficiency and accuracy of data collection are improved, and reliable data support is provided for subsequent carbon footprint analysis. The carbon footprint accounting accuracy of intermediate products and reflux process is improved, the problem of insufficient attention to intermediate products and reflux process in the existing method is overcome, and all carbon emission paths and links are reasonably included in the carbon footprint accounting system. The applicability and flexibility of carbon footprint accounting are enhanced, and the scalability of the modular multi-equation solving method makes the method suitable for petrochemical production processes of different scales and different processes, and has strong universality and adaptability.

[0007] As a preferred scheme, the module cumulative carbon footprint model inputs the sum of the carbon footprints of the intermediate products of the current module and the sum of the independent carbon footprints of the current module for all other modules.

[0008] In the complex petrochemical process, numerous material reflux and recycling are involved between devices, and the problem of carbon emission allocation between multiple products also needs to be considered. In the model construction process, the independent carbon footprint of the module excluding reflux is calculated based on the input and output of each module, i.e., the independent carbon footprint model is established based on the input and output of the module, except for the intermediate product as the material part. The independent carbon footprint of the module is calculated by the independent carbon footprint model. On the basis of the independent carbon footprint model, the cumulative carbon footprint model is established by accumulating the carbon footprints of the intermediate products supplied by other modules for use in the current module, which reflects the complex flow relationship of materials between modules.

[0009] As a preferred solution, the mass fraction of the intermediate product in the module is obtained by: determining the module where the intermediate product is output from; obtaining the total mass of all output products of the module, all products including the target product, the intermediate product and the byproduct, calculating the proportion of the intermediate product in the total mass of all products to obtain the mass fraction of the intermediate product.

[0010] The cumulative carbon footprint of each module is allocated to all products, including the target product, the intermediate product and the byproduct, according to the mass fraction principle, and the carbon footprint of the intermediate product output by each module is calculated and accumulated in the next module or other modules. The mass fraction of each product is the ratio of the mass of the product produced by the module to the sum of the mass of all products produced by the module, i.e. the mass proportion of the product in the module.

[0011] As a preferred solution, the carbon footprint of the intermediate product is obtained by: obtaining the carbon footprint of the intermediate product according to the product of the mass fraction of the intermediate product and the cumulative carbon footprint of the module.

[0012] Due to the complexity of petrochemical production processes, there are many material refluxes and recycling between devices, and the input of the module also includes the intermediate products of other modules. When there is reflux in the module, the product of the downstream module is refluxed as raw material to the upstream module, and the cumulative carbon footprint of the downstream module is unknown. Therefore, in the calculation process of the present application, the cumulative carbon footprint of the module is taken as an unknown quantity to construct a cumulative carbon footprint model, and finally all the cumulative carbon footprint models of the modules are solved together to obtain the cumulative carbon footprint of all the modules.

[0013] As a preferred solution, the cumulative carbon footprint models of all the modules are obtained, the cumulative carbon footprint is taken as an unknown quantity, equations are established, a multiple equation set is constructed by combining all the cumulative carbon footprint models, and the cumulative carbon footprint of each module is obtained by solving the equation set.

[0014] When there is reflux in the module, the cumulative carbon footprint of the downstream module is unknown. For the cumulative carbon footprint and independent carbon footprint of any module, a multiple equation set is satisfied, and the cumulative carbon footprint of each module can be obtained by solving the equation set.

[0015] As a preferred solution, The devices in the process flow are taken as the smallest accounting unit, and the process flow is divided into several modules according to the devices.

[0016] The present scheme is to modularize the process flow, take the device as the minimum accounting unit, modularize and package the process flow chart, structure a complex process system into several module units, model each module separately, ensure more accurate data collection and calculation of each module, make the accounting range more clear and transparent, facilitate the tracing of carbon footprint contribution of different module units, and identify emission hotspots. The beginning module and the end module in the accounting range are determined after the deconstruction, ensuring the integrity of the system input and output, wherein the beginning module is the initial raw material input module and the end module is the product output module.

[0017] As a preferred scheme, adjacent devices are merged based on data integrity, and the final device constitutes a module.

[0018] The following principles must be met for modular deconstruction. First, the data availability principle. Based on the availability of module energy consumption, material, and emission data, the module is deconstructed. If the data is complete, the module is refined to the smallest device. If the data is not complete, the module with incomplete data is merged with adjacent modules until a merged module with available data is obtained. Second, the module quantity maximization principle. Under the premise of data availability, the module is maximally split to improve the calculation accuracy and avoid treating the entire production process as a module. Finally, the uniqueness principle of modular deconstruction. For the same production process of the same product, the result of modular deconstruction is unique, ensuring the reproducibility and comparability of the carbon footprint of the product.

[0019] As a preferred scheme, a module independent carbon footprint model is established according to the input and output of the module, including: Determining the functional unit, reference flow, and accounting range of the target product carbon footprint calculation; Based on the flow relationship between the modules after process modularization, a module correlation diagram is established; Based on the module correlation diagram, the input and output flow between modules is determined, the flow relationship between modules is clarified, the emission sources of each module are integrated, and a module flow graph is constructed; Based on the module flow graph mapping, an emission inventory is generated, and data is collected according to the emission inventory; Establishing a module independent carbon footprint model according to the scope one carbon emission, scope two carbon emission, and scope three carbon emission.

[0020] Accounting target and range determination; determine the target product of accounting, the range includes functional unit, reference flow, and accounting range.

[0021] Process flow construction: Analyze the process of the target product, verify the accounting scope, generate process units, direct emissions, three wastes, and material and product flow relationships. Determine the main initial raw materials for the production of the target product within the accounting scope, the starting device of the first production process of the initial raw materials, the final target product, and the export device of the target product leaving the production process. Combine the actual production situation to construct the process flow.

[0022] The process flow analysis specifically includes: Material flow analysis: Identify the flow paths of main raw materials, auxiliary materials, and products, determine the key raw material feeding position, and assess the product destination. Energy flow analysis: Identify the energy input and usage of each production unit. Greenhouse gas and waste emission analysis: Determine the greenhouse gas emissions and waste disposal methods of each production unit, such as wastewater, waste gas, and solid waste.

[0023] Module decomposition: Decompose the target product process flow into multiple modules, with the device as the smallest accounting unit. Split and package the complex process system into several module units.

[0024] Constructing a module flow graph: First, establish a module correlation graph, which is based on the modular decomposition results and shows the material and product flow relationships between modules. Specifically, clarify the material input and output flow between modules, including raw material flow and auxiliary material flow, product flow, byproduct flow, and intermediate product flow. Ensure that all material flows are included to avoid missing key carbon footprint sources. Use a rectangular box to represent each accounting module and an arrow to represent material flow (raw materials, auxiliary materials, products, byproducts, etc.). For circulating material flow, such as a module's product supplying the previous module as a production raw material, ensure that the connection relationship is clear. Based on the module correlation graph, integrate direct and indirect emission sources in the entire process to form a module that includes all carbon emissions, providing a more accurate scope for carbon footprint accounting. Standardized symbols are used to represent different flow directions.

[0025] Emission inventory generation: Based on the module flow graph, sort the input and output emission sources of each module, classify the emission sources of each module, and fill in the corresponding emission inventory table to form a standard emission inventory. If there is a group of emission sources in the module flow graph, there is a corresponding group of data in the emission inventory table, forming a one-to-one correspondence between emission sources and data.

[0026] Data collection and analysis: Data collection includes real scene data and background data. Among them, the real scene data comes from the actual production process, including raw material consumption, energy consumption, product production, direct emission and three waste emissions. For the unit carbon footprint coefficient of purchased electricity and basic chemical raw materials, a suitable background database (such as ecoinvent, GaBi, etc.) needs to be selected. In the data analysis process, ensure the integrity, consistency and reasonableness of the data, and meet the selection rules.

[0027] Module carbon footprint model construction: From the beginning module, the carbon footprint model of each module is constructed one by one. According to the scope one, scope two and scope three carbon emissions, the module independent carbon footprint model is established. The module carbon footprint is allocated to each product by mass allocation. When the intermediate product produced by the upstream module is supplied to the downstream module, the carbon footprint of the intermediate product is accumulated to the downstream module. According to the input intermediate product carbon footprint and independent carbon footprint model, the module cumulative carbon footprint model is established as a preferred scheme. Determine the scope one carbon emission, including various greenhouse gas direct emissions, including CO2 emission, CH4 emission, N2O emission; Determine the scope two carbon emission, including power consumption emission, heat consumption emission; Determine the scope three carbon emission, including purchased raw material carbon emission, transportation carbon emission, waste treatment carbon emission.

[0028] In this scheme, the module independent carbon footprint model is established according to the scope one, scope two and scope three carbon emissions. The independent carbon footprint model is obtained by adding the three scope carbon emissions. The scope one carbon emission is direct carbon emission, including CO2, CH4, N2O and other greenhouse gas emissions; The scope two carbon emission is indirect energy emission, including power consumption, heat consumption and other indirect energy emissions; The scope three carbon emission is the upstream and downstream emissions on the supply chain, including purchased raw material carbon emission, transportation carbon emission, waste treatment carbon emission and other upstream and downstream emissions on the supply chain.

[0029] As a preferred scheme, the result analysis according to the module carbon footprint includes: According to the module independent carbon footprint, the contribution degree of the module in the petrochemical process is calculated, the high emission module is identified according to the contribution degree, and the corresponding carbon emission optimization is carried out on the high emission module.

[0030] Get the independent carbon footprint of all modules, add to get the whole petrochemical process carbon footprint, calculate the proportion of each module independent carbon footprint in the whole petrochemical process carbon footprint as the module contribution degree, identify the high emission module according to the contribution degree, and carry out the corresponding carbon emission optimization on the high emission module.

[0031] A complex petrochemical process modular deconstruction carbon footprint evaluation system, comprising, A target determination unit determines a target product, determines a functional unit for carbon footprint calculation, a reference flow, and an accounting scope; A module deconstruction unit deconstructs a process flow of the target product to form a plurality of modules; A model generation unit establishes a module independent carbon footprint model according to the scope 1 carbon emission, the scope 2 carbon emission, and the scope 3 carbon emission, and establishes a module cumulative carbon footprint model according to the input intermediate product carbon footprint and the independent carbon footprint model; A carbon footprint calculation unit calculates the cumulative carbon footprint of the module by simultaneously solving the cumulative carbon footprint models of all the modules; A result analysis unit performs result analysis according to the module carbon footprint.

[0032] Therefore, the present application has the following advantages: The present application deconstructs a petrochemical process into modules, constructs a carbon footprint model according to the numerous material reflux and recycling involved in each module, and jointly calculates the carbon footprint of each module by simultaneously solving the module carbon footprint models, thereby ensuring that the carbon footprint accounting has high accuracy and comparability.

[0033] The complex flow relationship between materials and energy among the production devices in the petrochemical process is considered, and the problem that it is difficult to obtain comprehensive and accurate actual production data and the background database is insufficiently supported, resulting in that the accounting result cannot accurately reflect the current product carbon footprint, is solved. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a process schematic diagram of the present application.

[0035] Figure 2 is a schematic diagram of a product production process in an embodiment of the present application.

[0036] Figure 3 is a schematic diagram of a module correlation diagram in an embodiment of the present application.

[0037] Figure 4 is a schematic diagram of a module flow graph in an embodiment of the present application.

[0038] Figure 5 is a schematic diagram of generating an emission list in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be further specifically described below by means of embodiments and in combination with the drawings.

[0040] Embodiment 1: The present embodiment is a complex petrochemical process modular deconstruction carbon footprint evaluation method, as shown in Figure 1 the following steps are included: S1. Determine the target product and the scope.

[0041] Determine the accounting target product, determine the scope including functional units, benchmark flow and accounting range.

[0042] S2. Analyze the target product process to build a process flow.

[0043] Through detailed analysis of the production process of the target product, verify the accounting range, generate process units, direct emissions, three wastes and material product flow relationship. Determine the main initial raw materials of the target product production in the accounting range, the starting device of the first production process of the initial raw materials, the final target product, and the export device of the target product leaving the production process, and build the process flow combined with the actual production situation.

[0044] The process flow analysis specifically includes: Material flow analysis: identify the flow path of main raw materials, auxiliary materials and products, determine the key raw material feeding position, and the material conversion relationship of each production unit, and evaluate the product destination; Energy flow analysis: identify the energy input and use of each production unit; Greenhouse gas and waste emission analysis: determine the greenhouse gas emissions and waste water, waste gas, solid waste and other waste emissions and treatment methods of each production unit.

[0045] S3. Disassemble the target product process flow to form multiple modules.

[0046] With the device as the smallest accounting unit, the process flow is split and packaged, and the complex process system is structured into several module units. Model each module separately to ensure more accurate data collection and calculation for each module, making the accounting range more clear and transparent, facilitating the tracing of carbon footprint contributions of different module units and identifying emission hotspots. After disassembly, the initial module and the final module in the accounting range are clear, ensuring the integrity of the system input and output, where the initial module is the initial raw material input module and the final module is the product output module.

[0047] Based on the data integrity, adjacent devices are merged to obtain the final device module.

[0048] The following principles must be met for modular disassembly: Data availability principle: based on the availability of module energy consumption, material, and emission data, the module is disassembled. If the data is complete, the module is refined to the smallest device. If the data is not complete, the module with incomplete data is merged with adjacent modules until the data of the merged module is available.

[0049] The principle of maximizing the number of modules, under the premise of data availability, maximizes the number of modules, improving the accuracy of accounting and avoiding treating the entire production process as a module.

[0050] Modular deconstruction is the principle of uniqueness. For the same production process of the same product, the result of modular deconstruction is unique, ensuring the reproducibility and comparability of the carbon footprint result of the product.

[0051] S4. Establish module association diagram.

[0052] The module association diagram is based on the results of modular deconstruction, showing the material and product flow relationship between modules. Specifically, clarify the material input and output flow between modules, including raw material flow and auxiliary material flow, product flow, by-product flow and intermediate product flow, ensure that all material flows are included, and avoid missing key carbon footprint sources. Use a rectangular box to represent each accounting module, and use arrows to represent material flow (raw materials, auxiliary materials, products, by-products, etc.). For circulating material flow, such as the product of a module being used as a raw material for the previous module, ensure that the connection relationship is clear.

[0053] S5. Construct module flow graph.

[0054] On the basis of the module association diagram, integrate the direct and indirect emission sources in the entire process to form a module containing all carbon emissions, providing a more accurate range for carbon footprint accounting. Among them, standardized symbols are used to represent different flow directions.

[0055] S6. Emission inventory generation.

[0056] Based on the analysis of input and output emission sources in the module flow graph, a dynamic mapping mechanism between the module flow graph and the carbon emission inventory data is established, which automatically identifies the carbon emission source data in the flow graph, and realizes the automatic linkage between the visualization result and the carbon emission data source.

[0057] S7. Data collection and analysis.

[0058] Data collection includes real scene data and background data. The real scene data comes from the actual production process, including raw material consumption, energy consumption, product production, direct emission and three waste emissions. For the unit carbon footprint coefficient of purchased electricity and basic chemical raw materials, a suitable background database (such as ecoinvent, GaBi, etc.) needs to be selected. In the data analysis process, ensure the completeness, consistency and reasonableness of the data, and meet the selection rules.

[0059] S7. Module carbon footprint model construction, including: S71. Establish module independent carbon footprint model according to the input and output of the module; Specifically, starting from the initial module, the carbon footprint model of each module is constructed one by one. For each module, establish a module independent carbon footprint model according to the scope one, scope two and scope three carbon emissions.

[0060] Scope 1 carbon emissions, including direct emissions of various greenhouse gases, such as CO2 emissions, CH4 emissions, N2O emissions; Scope 2 carbon emissions, including power consumption emissions, heat consumption emissions; Scope 3 carbon emissions, including purchased raw material generated carbon emissions, transportation carbon emissions, waste disposal carbon emissions.

[0061] The independent carbon footprint model is the sum of Scope 1, Scope 2, and Scope 3 carbon emissions, and the carbon footprint of mold i is represented as follows: ICF(i) = CFS1(i) + CFS2(i) + CFS3(i) Where ICF(i) represents the independent carbon footprint of mold i, CFS1(i) represents the Scope 1 carbon emissions of mold i, CFS2(i) represents the Scope 2 carbon emissions of mold i, and CFS3(i) represents the Scope 3 carbon emissions of mold i.

[0062] Scope 1 carbon emissions: Where m a represents the amount of various greenhouse gas emissions, and a represents the type of greenhouse gas. Scope 2 carbon emissions: CFS2(i) = E e × PCE e + H h × PCE h Where E e represents power consumption, PCF e represents the power carbon footprint coefficient, H h represents heat consumption, PCF h represents the heat carbon footprint coefficient.

[0063] Scope 3 carbon emissions: CFS3(i) = CFS3M(i) + CFS3W(i) + CFS3T(i) Where CFS3M(i) represents raw material generated carbon emissions, CFS3W(i) represents carbon emissions during waste disposal, and CFS3T(i) represents transportation process carbon emissions, M m represents the amount of raw materials consumed, PCF m represents the raw material carbon footprint coefficient, W w represents the amount of waste disposal, PCF w represents the carbon footprint coefficient of waste disposal, T t represents the transportation mass, D t represents the transportation distance, PCF tThe transport carbon footprint coefficient is denoted by

[0064] S72. Calculate the mass fraction of all products of the module according to the mass fraction principle.

[0065] The products produced by the module include intermediate products and by-products, and the final module located at the most downstream also includes target products.

[0066] Except for the most downstream final module, the module I∈[1, n-1], I≠j produces k intermediate products IP mass fraction flowing to the module j∈[1, n]: Where n represents the number of all modules, mIP I-j，k represents the mass of k intermediate products produced by module I flowing to module j, m I represents the sum of the mass of all products of module I, mIP I represents the sum of the mass of all intermediate products produced by module I, mBP l represents the sum of the mass of all by-products produced by module I.

[0067] The module I produces k by-products BP mass fraction: Where mBP l，k represents the mass of k by-products produced by module I.

[0068] For the most downstream module, the mass fraction of all products includes, The module n produces target product mass fraction: Where module n is the most downstream module, m n represents the sum of the mass of all products of module n, mP n represents the mass of target products produced by module n, mIP n represents the sum of the mass of all intermediate products produced by module n, mBP n represents the sum of the mass of all by-products produced by module n.

[0069] The module n produces k intermediate products IP mass fraction flowing to the module j: Where mIP n-j，k represents the mass of k intermediate products produced by module n flowing to module j, m n represents the sum of the mass of all products of module n .

[0070] The module n produces k by-products BP mass fraction: wherein, mBP n，k represents the quality of k items of by-products produced by module n.

[0071] S73. Establishing a module cumulative carbon footprint model according to the input intermediate product carbon footprint and the independent carbon footprint model, the intermediate product carbon footprint being obtained according to its quality fraction in the module and the cumulative carbon footprint of the module.

[0072] The cumulative carbon footprint of a module is obtained by calculation of the module cumulative footprint model. The cumulative carbon footprint of a module is the carbon footprint of the intermediate product supplied by any module j on the basis of the independent carbon footprint, which reflects the complex material flow relationship between modules. The cumulative carbon footprint of module i∈[1, n], i≠j (module i includes all modules I and module n) and the cumulative carbon footprint model of the carbon footprint of the intermediate product supplied by any module j are: wherein, CF(i) represents the cumulative carbon footprint of module i, fIP j-i represents the quality fraction of k items of intermediate products produced by module j and supplied to module i for use as raw materials in all products of module j, CF(j) represents the cumulative carbon footprint of module j, and i≠j.

[0073] S74. Calculating the cumulative carbon footprint of all modules by simultaneously solving the cumulative carbon footprint models of all modules.

[0074] When there is partial reflux in a module, the products of a downstream module are refluxed to an upstream module as raw materials, the CF(i) of the downstream module is an unknown quantity. The CF(i) of any module i and the ICF(i) satisfy a multivariate equation set, and the equation set is obtained as: Solving the equation set can obtain the CF(i) value, i.e. the cumulative carbon footprint of each module.

[0075] S8. Performing result analysis according to the module carbon footprint.

[0076] According to the module independent carbon footprint, the contribution degree of the module in the petrochemical process is calculated, the high-emission module is identified according to the contribution degree, and the corresponding carbon emission optimization is performed on the high-emission module.

[0077] The independent carbon footprints of all modules are obtained, the entire petrochemical process carbon footprint is obtained by addition, the contribution degree of each module independent carbon footprint in the entire petrochemical process carbon footprint is calculated as the module contribution degree, the high-emission module is identified according to the contribution degree, and the corresponding carbon emission optimization is performed on the high-emission module.

[0078] Based on the constructed module carbon footprint model, the mass fraction of each module, the module independent carbon footprint, the module cumulative carbon footprint, the product carbon footprint and the product carbon footprint coefficient of all products in each module are calculated one by one to obtain the target product carbon footprint and the carbon footprint coefficient.

[0079] The cumulative carbon footprint of each module is distributed to all products in the module according to the mass, so the target product carbon footprint of module n is: CFP n = fP n × CF(n) The carbon footprint of k intermediate products IP flowing from module i to module j: CFIP i-j，k = fIP i-j，k × CF(i) The carbon footprint of k by-products BP produced by module i: CFBP i，k = fBP i，k × CF(i) Based on the mass distribution, the carbon footprint coefficients of all target products, intermediate products and by-products produced by the same module are equal, which are expressed as: The carbon footprint of the entire petrochemical process containing all modules is calculated: CF total = ICF(1) + ICF(2) + … + ICF(i) The carbon footprint contribution degree of each module:

[0080] According to the contribution degree, high-emission modules are identified, and corresponding carbon emission optimization is performed on the high-emission modules.

[0081] The embodiment also includes a complex petrochemical process modular deconstruction carbon footprint evaluation system for implementing the above method, and the system includes: A target determination unit determines the target product, determines the functional unit for carbon footprint calculation, the reference flow and the accounting range; A module deconstruction unit deconstructs the target product process to form a plurality of modules; A model generation unit establishes a module independent carbon footprint model according to the range one, range two and range three emissions, and establishes a module cumulative carbon footprint model according to the input intermediate product carbon footprint and independent carbon footprint model; A carbon footprint calculation unit simultaneously calculates the cumulative carbon footprint of all modules; A result analysis unit analyzes the results according to the module carbon footprint.

[0082] Example 2: The embodiment discloses a complex petrochemical process modular decomposition carbon footprint evaluation method, and uses examples to illustrate the carbon footprint of p-xylene produced by a petrochemical enterprise, which comprises the following steps: S1. Determine the target product and the scope.

[0083] The target product is p-xylene, and the target product related function unit, reference flow and accounting range are as follows: Function unit: 1 ton of p-xylene; Reference flow: 1 ton of p-xylene; Accounting range: from cradle to gate process.

[0084] S2. Analyze the target product process to construct a process flow.

[0085] The process uses naphtha as raw material and adopts continuous reforming technology to produce p-xylene. The specific process flow includes naphtha hydrogenation, continuous reforming reaction, catalyst regeneration, aromatic distillation, disproportionation and alkylation, extraction, isomerization, adsorption separation and other processes to produce p-xylene. Based on the process production related flow, the material flow, energy flow, greenhouse gas and other emissions and waste discharge types of each device are determined, and the specific information is shown in Table 1. The initial raw material is determined as naphtha, the starting device is determined as the continuous reforming device, the target product is determined as p-xylene, and the outlet device is determined as the adsorption separation device. The process flow is constructed as shown in Figure 1 .

[0086] Table 1 Product process flow information S3. Decompose the target product process flow to form a plurality of modules.

[0087] Combined with the availability of process data, the process flow is modularly decomposed with the device as the minimum accounting unit. Since the data of the pretreatment unit, the reforming reaction unit and the catalyst regeneration unit cannot be obtained alone, the actual data is the statistics of the continuous reforming device. Therefore, the process is decomposed into five modules: module one (continuous reforming device), module two (aromatic distillation device), module three (disproportionation device), module four (extraction device) and module five (adsorption separation device). The initial module is module one (continuous reforming device), and the final module is module five (adsorption separation device).

[0088] S4. Establish a module correlation diagram.

[0089] Based on the results of the modular decomposition, a module correlation diagram of the p-xylene process is constructed to clearly show the material input and output flow relationship between the modules, as shown in Figure 2 .

[0090] S5. Construct a module flow graph.

[0091] On the basis of the module correlation diagram, the emission sources of the entire module, including purchased raw materials, electricity and heat and other energy, direct emissions, waste emissions, intermediate products, byproducts and target products, etc. are represented by standardized symbols to represent different emission types, forming a module flow diagram, as shown in Figure 3 .

[0092] S6. Emission inventory generation.

[0093] Based on the module flow diagram, the input and output emission sources of each module are sorted out, and the corresponding emission inventory table is generated by mapping. The emission sources in the flow diagram correspond one-to-one with the data in the emission inventory. As shown in Figure 4 , take module one as an example, generate the corresponding emission inventory.

[0094] S7. Module carbon footprint model construction.

[0095] S71. Establish a module independent carbon footprint model according to the input and output of the module; Using a step-by-step accounting method, start from the initial module and build the carbon footprint model of each module one by one. For each module, establish a module independent carbon footprint model according to the scope one, scope two and scope three emissions.

[0096] Determine the scope one carbon emissions, including various greenhouse gas direct emissions, such as CO2 emissions, CH4 emissions, N2O emissions; Determine the scope two carbon emissions, including electricity consumption emissions, heat consumption emissions; Determine the scope three carbon emissions, including purchased raw materials carbon emissions, transportation carbon emissions, waste disposal carbon emissions.

[0097] The independent carbon footprint model is the sum of the carbon emissions of the three scopes, then the carbon footprint of module i is represented as follows: ICF(i) = CFS1(i) + CFS2(i) + CFS3(i) Scope one carbon emissions: Scope two carbon emissions: CFS2(i) = E e × PCE e + H h × PCE h Scope three carbon emissions: CFS3(i) = CFS3M(i) + CFS3W(i) + CFS3T(i) S72. Calculate the quality score of all products of the module according to the quality score principle.

[0098] S73. Build a cumulative carbon footprint model for the module from the input intermediate product carbon footprint and the independent carbon footprint model.

[0099] Module one: feed S3M1, output streams: intermediate product IP(1-2), intermediate product IP(1-3), by-product BP(1).

[0100] Mass fractions of intermediate products and by-products: Module one independent carbon footprint: ICF(1) = CFS1(1) + CFS2(1) + CFS3(1) Module one cumulative carbon footprint: CF(1) = ICF(1) Carbon footprints of intermediate products IP(1-2), IP(1-3) and by-product BP(1): CFIP 1-2，1 = fIP 1-2,1 x CF(1) CFIP 1-3,1 = fIP 1-3,1 x CF(1) CFBP 1，1 = fBP 1，1 x CF(1) Carbon footprint factors of intermediate products IP(1-2), IP(1-3) and by-product BP(1): Module two: feed S3M2 and intermediate products IP(1-2), IP(3-2), IP(4-2), IP(5-2), output streams: intermediate products IP(2-3), IP(2-4), IP(2-5) and by-product BP(2).

[0101] Mass fractions of intermediate products IP(2-3), IP(2-4), IP(2-5) and by-product BP(2): Module two independent carbon footprint: ICF(2) = CFS1(2) + CFS2(2) + CFS3(2) Module two cumulative carbon footprint: CF(2) = ICF(2) + fIP 1-2，1 x CF(1) + fIP 3-2,1 x CF(3) + fIP 4-2,1 x CF(4) + fIP 5-2,1 x CF(5) Carbon footprint of intermediate products IP(2-3), IP(2-4), IP(2-5) and by-product BP(2): CFIP 2-3,1 = fIP 2-3,1 x CF(2) CFIP 2-4，1 = fIP 2-4,1 x CF(2) CFIP 2-5,1 = fIP2 2-5,1 x CF(2) CFBP 2,1 = fBP 2，1 x CF(2) Carbon footprint factors of intermediate products IP(2-3), IP(2-4), IP(2-5) and by-product BP(2): Module three: feed S3M3 and IP(2-3), IP(1-3), product streams: intermediate product IP(3-2) and by-product BP(3).

[0102] Mass fractions of intermediate product IP(3-2) and by-product BP(3): Module three independent carbon footprint: ICF(3) = CFS1(3) + CFS2(3) + CFS3(3) Module three cumulative carbon footprint: CF(3) = ICF(3) + fIP 2-3,1 x CF(2)) + fIP 1-3,1 x CF(1) Carbon footprint of intermediate product IP(3-2) and by-product BP(3): CFIP 3-2，1 = fIP 3-2,1 x CF(3) CFBP 3，1 = fBP 3，1 x CF(3) Carbon footprint factors of intermediate product IP(3-2) and by-product BP(3): Module four: feed S3M4 and intermediate product IP(2-4), output streams: intermediate product IP(4-2) and by-product BP(4).

[0103] Mass fractions of intermediate product IP(4-2) and by-product BP(4): Module four independent carbon footprint: ICF(4) = CFS1(4) + CFS2(4) + CFS3(4) Module four cumulative carbon footprint: CF(4) = ICF(4) + fIP 2-4,1 x CF(2) Carbon footprint of intermediate product IP(4-2) and by-product BP(4): CFIP 4-2,1 = fIP 4-2,1 x CF(4) CFBP 4，1 = fBP 4，1 x CF(4) Carbon footprint factors of intermediate product IP(4-2) and by-product BP(4): Module five: feed: S3M5 and intermediate product IP(2-5), output stream: intermediate product IP(5-2), by-product BP(5) and target product P(5).

[0104] Mass fractions of intermediate product IP(5-2), by-product BP(5) and target product P(5): Module five independent carbon footprint: ICF(5) = CFS1(5) + CFS2(5) + CFS3(5) Module five cumulative carbon footprint: CF(5) = ICF(5) + fIP 2-5,1 x CF(2) Carbon footprint of intermediate product IP(5-2), by-product BP(5) and target product P(5): CFIP 5-2,1 = fIP 5-2,1 x CF(5) CFBP 5,1 = fBP 5，1 x CF(5) CFP5 = fP5 x CF(5) Carbon footprint factors of intermediate product IP(5-2), by-product BP(5) and target product P(5): S74. Calculate the cumulative carbon footprint of all modules by simultaneously solving the cumulative carbon footprint models of all modules.

[0105] There is partial backflow in the module, and CF(2), CF(3), CF(4) and CF(5) in the module are unknown numbers. The following equation group is obtained by cumulatively modeling the carbon footprint of all modules: CF(1) = ICF(1) CF(2) = ICF(2) + fIP 1-2,1 ×CF(1) + fIP 3-2,1 ×CF(3) + fIP 4-2,1 ×CF(4) +fIP 5-2,1 ×CF(5) CF(3) = ICF(3) + fIP 2-3，1 ×CF(2) + fIP 1-3,1 ×CF(1) CF(4) = ICF(4) + fIP 2-4，1 ×CF(2) CF(5) = ICF(5) + fIP 2-5,1 ×CF(2) Solving the equation group can obtain the cumulative carbon footprint of all modules.

[0106] S8. Analyzing the results according to the carbon footprint of the modules.

[0107] The carbon footprint of the entire petrochemical process containing all modules is calculated as follows: CF total = ICF(1) + ICF(2) + ICF(3) + ICF(4) + ICF(5) The contribution of the carbon footprint of each module:

[0108] According to the contribution, identify the high-emission module, and optimize the corresponding carbon emission of the high-emission module.

[0109] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, but will not deviate from the spirit of the present application or exceed the scope defined by the appended claims.

Claims

1. A method for modular deconstruction of carbon footprint assessment of complex petrochemical processes, characterized in that, The method comprises the following steps: determining a target product, and decomposing a process flow of the target product into a plurality of modules; establishing a module independent carbon footprint model according to input and output of the modules; establishing a module cumulative carbon footprint model according to an input intermediate product carbon footprint and the independent carbon footprint model, the intermediate product carbon footprint being obtained according to a mass fraction of the intermediate product in a module and a cumulative carbon footprint of the module; calculating cumulative carbon footprints of all the modules by simultaneously solving the cumulative carbon footprint models of all the modules; performing result analysis according to the module carbon footprints.

2. The method according to claim 1, wherein the cumulative carbon footprint model is a sum of carbon footprints of intermediate products input into the current module by all other modules and a sum of independent carbon footprints of the current module. Module The mass fraction of the intermediate product in the module is obtained by:

3. A method of evaluating carbon footprint of a complex petrochemical process in a modularized manner according to claim 2, characterized in that, determining the module in which the intermediate product is located according to an output source of the intermediate product; obtaining a total mass of all output products of the module, the output products including the target product, the intermediate product and by-products, and calculating a proportion of the intermediate product in the total mass of all the products to obtain the mass fraction of the intermediate product. The intermediate product carbon footprint is obtained by:

4. The method of claim 3, wherein the method is characterized by, multiplying the mass fraction of the intermediate product by the cumulative carbon footprint of the module to obtain the intermediate product carbon footprint.

5. The method according to any one of claims 1 to 4, wherein the cumulative carbon footprints of all the modules are obtained by: establishing equations with the cumulative carbon footprints as unknown quantities, constructing a multivariate equation system by combining all the cumulative carbon footprint models, and solving the equation system to obtain the cumulative carbon footprints of the modules. The process flow of the target product is decomposed into a plurality of modules by:

6. The method of claim 1, wherein the method is characterized by, dividing the process flow into a plurality of modules according to devices in the process flow.

7. The method according to claim 6, wherein the devices are merged based on data integrity to obtain the modules. The module independent carbon footprint model is established according to input and output of the modules by: determining a functional unit for calculating the carbon footprint of the target product, a reference flow and a calculation range; 8. The method of claim 1 or 6, wherein the method is characterized in that, establishing a module correlation diagram based on flow relationships between the modules after the process is modularized; clearing the flow relationships between the modules, integrating emission sources of the modules, and constructing a module flow graph based on the module correlation diagram; generating an emission list based on the module flow graph, and collecting data according to the emission list; establishing the module independent carbon footprint model according to range 1 carbon emission, range 2 carbon emission and range 3 carbon emission.

9. The method according to claim 8, wherein the range 1 carbon emission includes direct emission of various greenhouse gases. The range 2 carbon emission includes emission caused by power consumption and heat consumption. The range 3 carbon emission includes carbon emission caused by purchased raw materials, transportation and waste disposal. The result analysis according to the module carbon footprints comprises: ​ ​ 10. A method of evaluating carbon footprint of a complex petrochemical process in a modular deconstruction according to claim 9, characterized in that, ​ According to the contribution degree of the module independent carbon footprint calculation module in the whole petrochemical process, the high emission module is identified according to the contribution degree, and the corresponding carbon emission optimization is carried out on the high emission module.

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