Coal-fired unit carbon emission accounting method and system for beccs and medium

Abstract

The application discloses a coal-fired unit carbon emission accounting method and system for BECCS, and a medium, and relates to the technical field of carbon emission accounting, which comprises the following steps: obtaining full-chain accounting basic data sets, including fuel basic parameters, emission factor parameters, coal-fired unit operation parameters, supply chain parameters and CCS system parameters; taking a predetermined unified power supply quantity benchmark and an accounting boundary as core benchmarks to determine the benchmark emission of the pure coal combustion benchmark line full life cycle link, the first carbon emission corresponding to the biomass replacement emission reduction link of the BECCS scenario combustion emission, the second carbon emission corresponding to the biomass supply full life cycle link, the third carbon emission corresponding to the raw coal supply chain link in the BECCS scenario, the fourth carbon emission corresponding to the power generation efficiency loss additional link, the fifth carbon emission corresponding to the CO2 capture system full link, the sixth carbon emission corresponding to the CO2 transportation and storage link, and calculating the net carbon emission of the BECCS scenario full life cycle.

Description

Technical Field

[0001] This invention relates to the field of carbon emission accounting technology, specifically to carbon emission accounting methods, systems, and media for coal-fired power units oriented towards BECCS. Background Technology

[0002] Against the backdrop of global climate change and profound energy structure transformation, reducing carbon dioxide emissions during fossil fuel utilization has become one of the core objectives of energy and environmental policies in various countries. Coal-fired power generation, as a crucial foundational power source in the current power system, can no longer achieve deep emission reduction targets simply through energy efficiency improvements and end-of-pipe treatment. In this context, biomass co-firing power generation with carbon capture, utilization, and storage (CCUS) technology is considered an important technological path for coal-fired units to achieve near-zero or even negative emissions. In particular, the Bio-energy with Carbon Capture and Storage (BECCS) model, which couples biomass co-firing with carbon capture and storage (CCS) technology, can theoretically achieve "net negative emissions" in the power generation process through carbon absorption during biomass growth and CO2 capture and storage after combustion, attracting widespread attention.

[0003] However, the carbon emission process of coal-fired units under the BECCS model is highly complex. Its sources include not only boiler combustion emissions, but also multiple stages such as the biomass supply chain (acquisition, transportation, pretreatment), coal supply processes, CCS system operating energy consumption, additional fuel consumption due to changes in power generation efficiency, and leakage emissions during CO2 transportation and storage. Significant differences exist between these stages in terms of time scale, spatial scale, and energy conversion pathways.

[0004] Currently, the main technical approaches for carbon emission accounting methods related to coal-fired power generation, biomass power generation, and CCUS include the following:

[0005] 1. Emission factor method based on fuel mass or fuel consumption

[0006] This type of method uses fuel consumption as activity data and combines it with parameters such as unit fuel carbon content and oxidation rate to calculate CO2 emissions. It is widely used in corporate greenhouse gas accounting, emission inventory preparation and carbon trading compliance.

[0007] 2. Carbon emission accounting methods based on life cycle assessment (LCA)

[0008] This type of method calculates greenhouse gas emissions from the entire process of fuel production, transportation, conversion, and end-use from a "cradle to gate" or "cradle to grave" perspective, and is often used to assess the emission reduction potential of biomass energy, renewable energy, and CCUS technologies.

[0009] 3. Simplified accounting methods for biomass co-firing or CCUS

[0010] In some studies or engineering practices, carbon emissions under biomass co-firing or CCUS scenarios are simplified by assuming that the biomass combustion process is "zero-emission" or by using a fixed capture rate and a fixed efficiency penalty coefficient.

[0011] The disadvantages of the above-mentioned existing technologies are: (1) Some methods only use fuel quality as the accounting basis and have not been uniformly converted to the energy scale, making them difficult to apply to different calorific value fuel blending conditions; (2) The changes in power generation efficiency caused by biomass blending ratio and CCUS capture process are often simplified or implied in the emission factors and do not explicitly reflect the engineering operation characteristics; (3) The baseline and emission reduction scenario are inconsistent in system boundary and functional unit, which can easily lead to deviations in the carbon emission reduction calculation results; (4) There is a lack of systematic and modular unified accounting methods for biomass supply chain, transportation, pretreatment and CCUS-related additional emissions.

[0012] In view of the above, this application is hereby submitted. Summary of the Invention

[0013] The technical problem this invention aims to solve is that current carbon emission accounting methods for coal-fired power units, biomass power generation, or CCUS technology are mostly based on emission factor methods or life cycle assessment (LCA) methods, and are usually applied to a single technology or scenario, making them difficult to directly apply to BECCS operation modes. Furthermore, existing methods lack unified standards in terms of accounting benchmarks, system boundaries, and efficiency impact handling, resulting in poor comparability of accounting results between different studies or engineering projects. The purpose of this invention is to provide a carbon emission accounting method, system, and medium for coal-fired power units oriented towards BECCS, specifically for calculating carbon emissions and carbon reductions for biomass-co-fired power units coupled with carbon capture and storage (CCS) technology. This invention is based on a unified power supply benchmark and introduces efficiency corrections to improve the accuracy and comparability of carbon emission and carbon reduction calculation results, thereby enhancing its practical industrial application value.

[0014] This invention is achieved through the following technical solution:

[0015] In a first aspect, the present invention provides a method for carbon emission accounting of coal-fired power units for BECCS, the method comprising:

[0016] Obtain the full-chain accounting basic dataset, which includes fuel basic parameters, emission factor parameters, coal-fired unit operating parameters, supply chain parameters, and CCS system parameters, etc.

[0017] Based on the full-chain accounting dataset, and with the predetermined unified power supply benchmark and accounting boundary as the core benchmark, the following are determined: the benchmark emissions corresponding to the entire life cycle of pure coal combustion, the first carbon emissions corresponding to the combustion emissions in the BECCS scenario, the second carbon emissions corresponding to the entire life cycle of biomass supply, the third carbon emissions corresponding to the raw coal supply chain in the BECCS scenario, the fourth carbon emissions corresponding to the additional emissions from power generation efficiency loss, the fifth carbon emissions corresponding to the entire CO2 capture system, and the sixth carbon emissions corresponding to the CO2 transportation and storage.

[0018] Based on the first, second, third, fourth, fifth, and sixth carbon emissions and the negative CO2 emission deduction, calculate the net carbon emissions over the entire life cycle of the BECCS scenario.

[0019] Furthermore, the method for determining the unified power supply benchmark and accounting boundary is as follows:

[0020] Based on the basic information of coal-fired power units, the BECCS retrofit technical plan and accounting requirements, the accounting boundaries covering the entire life cycle of raw coal and biomass, boiler combustion, power generation, and carbon capture, transportation and storage are delineated.

[0021] It also establishes a unified power supply benchmark E that is shared by the baseline pure coal working condition and the BECCS scenario, and clarifies the accounting cycle and the data caliber specifications for the entire process.

[0022] Furthermore, the process for determining the baseline emissions is as follows:

[0023] Using the predetermined unified power supply benchmark and accounting boundary as the core benchmark, and based on the raw coal basic parameters, emission factor set, raw coal supply chain parameters and unit plant power parameters in the full-chain accounting basic dataset, the benchmark intermediate quantity one, benchmark intermediate quantity two and benchmark intermediate quantity three are calculated in sequence.

[0024] The values ​​of reference intermediate quantity one, reference intermediate quantity two, and reference intermediate quantity three are added together to obtain the reference emission quantity; at the same time, the unit power supply efficiency under the reference emission quantity operating condition is output. ;

[0025] Among them, the first benchmark intermediate quantity is the fossil source CO2 emission generated by the combustion of pure coal at the baseline; the second benchmark intermediate quantity is the carbon emission of the entire process of raw coal mining, washing, and transportation; and the third benchmark intermediate quantity is the carbon emission generated by the auxiliary energy consumption of conventional plant power.

[0026] Furthermore, the process for determining the first carbon emission is as follows:

[0027] Using a predetermined unified power supply benchmark and accounting boundary as the core benchmark, and based on basic data such as raw coal and biomass fuel parameters, biomass blending ratio, and CO2 capture rate parameters in the full-chain accounting basic dataset, the fossil source CO2 emissions are calculated. CO2 emissions from biomass sources ;

[0028] Among them, fossil source CO2 emissions The figures represent fossil-source CO2 emissions and biomass-source CO2 emissions from the combustion of surplus raw coal under the BECCS scenario. This refers to the CO2 emissions from biomass combustion.

[0029] Furthermore, the process for determining the second and third carbon emissions is as follows:

[0030] Based on the biomass consumption, supply chain parameters, emission factor set, and agricultural input application data in the whole-chain accounting basic dataset, the carbon emissions of the biomass production and collection stage, the carbon emissions of the long-distance transportation stage, and the carbon emissions of the crushing and molding pretreatment stage are calculated in sequence.

[0031] The second carbon emission figure is obtained by summing the carbon emissions from the biomass production and collection process, the carbon emissions from the long-distance transportation process, and the carbon emissions from the crushing and pre-treatment process. ;

[0032] The process for determining the third carbon emission level is as follows:

[0033] Based on the raw coal consumption, mining and washing parameters, transportation parameters, and corresponding emission factors in the full-chain accounting basic dataset, the third carbon emissions from the raw coal mining, washing, and transportation processes are calculated. .

[0034] Furthermore, the expression for the fourth carbon emission is:

[0035] ;

[0036] in, The total additional carbon emissions resulting from power generation efficiency loss. The fifth carbon emission is the fossil-source carbon emissions resulting from the additional consumption of raw coal due to efficiency losses. E represents the carbon emissions from biomass sources resulting from additional biomass consumption due to efficiency losses, with E serving as a uniform power supply benchmark. The calorific value of biomass fuels and the blending ratio under the BECCS scenario. For the unit power supply efficiency under the BECCS scenario, The power supply efficiency of the unit under the baseline pure coal operating condition is used as a reference. The lower heating value of raw coal is the base calorific value. The carbon content per unit of calorific value of raw coal. The carbon oxidation rate of raw coal refers to the mass ratio of carbon elements oxidized to CO2 during the combustion of raw coal to the total carbon content. For biomass to receive lower heating value, The carbon content per unit of calorific value of biomass. The carbon oxidation rate of biomass.

[0037] Furthermore, the process for determining the fifth carbon emission level is as follows:

[0038] Based on the carbon capture system operating parameters, emission factor set, solvent replenishment and related parameters, and fossil-source CO2 emissions from the full-chain accounting basic dataset. And the theoretically cultivable total, in order of fifth carbon emissions I, fifth carbon emissions II, and fifth carbon emissions III;

[0039] Adding the values ​​of Fifth Carbon Emission I, Fifth Carbon Emission II, and Fifth Carbon Emission III together yields the Fifth Carbon Emission. ;

[0040] Among them, the fifth carbon emission one is the carbon emission generated by the auxiliary power consumption of the capture system, the fifth carbon emission two is the carbon emission generated by the solvent reheat consumption, and the fifth carbon emission three is the carbon emission generated by the production and replenishment of capture solvent.

[0041] Simultaneously, the theoretically survivable total CO2 from fossil sources and biomass sources are calculated; and based on these theoretically survivable total CO2 from fossil sources, the theoretically survivable total CO2 from biomass sources, and the CO2 leakage rate of the CO2 capture system, the CO2 negative emission offset is calculated. .

[0042] Furthermore, the process for determining the sixth carbon emission level is as follows:

[0043] Based on the CO2 transportation and storage parameters, corresponding emission factor sets, transportation distance and mode parameters, energy consumption parameters in the storage stage, and CO2 negative emission deduction amount in the full-chain accounting basic dataset. The carbon emissions generated by energy consumption in the CO2 transportation process, the leakage emissions in the transportation and geological storage processes, and the carbon emissions generated by auxiliary energy consumption in the storage process are calculated in sequence.

[0044] The sixth carbon emission figure is obtained by summing up the carbon emissions from energy consumption during CO2 transportation, the leakage emissions during transportation and geological storage, and the carbon emissions from auxiliary energy consumption during storage. .

[0045] Furthermore, the formula for calculating net carbon emissions is:

[0046] ;

[0047] in, Net carbon emissions For fossil-source CO2 emissions, This is the second largest source of carbon emissions. It is the third largest source of carbon emissions. It is the fourth largest carbon emission source. It is the fifth largest carbon emission source. It is the sixth largest carbon emission. This is a deduction amount for negative CO2 emissions.

[0048] Secondly, this invention also provides a carbon emission accounting system for coal-fired power units oriented towards BECCS, the system comprising:

[0049] The acquisition unit is used to acquire the basic dataset for full-chain accounting. The basic dataset for full-chain accounting includes fuel basic parameters, emission factor parameters, coal-fired unit operating parameters, supply chain parameters, and CCS system parameters, etc.

[0050] The first calculation unit is used to determine the baseline emissions corresponding to the entire life cycle of pure coal combustion baseline, the first carbon emissions corresponding to the combustion emissions in the BECCS scenario, the second carbon emissions corresponding to the entire life cycle of biomass supply, the third carbon emissions corresponding to the raw coal supply chain in the BECCS scenario, the fourth carbon emissions corresponding to the additional emissions from power generation efficiency loss, the fifth carbon emissions corresponding to the entire CO2 capture system, and the sixth carbon emissions corresponding to the CO2 transportation and storage, based on the full-chain accounting basic dataset and with a predetermined unified power supply benchmark and accounting boundary as the core benchmark.

[0051] The second calculation unit is used to calculate the net carbon emissions over the entire life cycle of the BECCS scenario based on the first carbon emissions, the second carbon emissions, the third carbon emissions, the fourth carbon emissions, the fifth carbon emissions, the sixth carbon emissions, and the negative CO2 emission deduction.

[0052] Thirdly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calculating carbon emissions from coal-fired power units oriented towards BECCS.

[0053] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0054] This invention provides a method, system, and medium for calculating carbon emissions from coal-fired power units using BECCS (Biomass Co-firing System). It offers a method for calculating carbon emissions and carbon reductions from coal-fired power units that are coupled with carbon capture and storage (CCS) technology. The invention is based on a unified power supply benchmark and incorporates efficiency corrections to improve the accuracy and comparability of the calculated carbon emissions and carbon reductions, thereby enhancing its practical industrial application value. Attached Figure Description

[0055] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0056] Figure 1 This is a flowchart of the carbon emission accounting method for coal-fired power units oriented towards BECCS according to the present invention;

[0057] Figure 2 This is a structural block diagram of the carbon emission accounting system for coal-fired power units according to the present invention, which is oriented towards BECCS. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0059] Example 1

[0060] like Figure 1 As shown, this invention provides a carbon emission accounting method for coal-fired power units oriented towards BECCS. The method includes:

[0061] S1. Obtain the full-chain accounting basic dataset, which includes fuel basic parameters, emission factor parameters, coal-fired unit operating parameters, supply chain parameters, and CCS system parameters, etc.

[0062] In this embodiment, the present invention constructs a verified full-chain accounting foundation dataset based on external basic data such as emission factors released by regional authorities, and internal operational data such as enterprise-side fuel intake inspection reports, unit operation history ledgers, CCS system design and operation parameters, and energy and material consumption ledgers. This dataset is organized according to basic fuel parameters (including basic parameters of raw coal and biomass), emission factor parameters, unit operation parameters, supply chain parameters, and CCS system parameters. This full-chain accounting foundation dataset will serve as the sole input data source for all subsequent sub-item accounting stages.

[0063] S2, based on the full-chain accounting basic dataset, with the predetermined unified power supply benchmark and accounting boundary as the core benchmark, determines the benchmark emissions corresponding to the entire life cycle of pure coal combustion, the first carbon emissions corresponding to the combustion emissions in the BECCS scenario, the second carbon emissions corresponding to the entire life cycle of biomass supply, the third carbon emissions corresponding to the raw coal supply chain in the BECCS scenario, the fourth carbon emissions corresponding to the additional generation efficiency loss, the fifth carbon emissions corresponding to the entire CO2 capture system, and the sixth carbon emissions corresponding to the CO2 transportation and storage.

[0064] In this embodiment, determining a unified power supply benchmark and accounting boundary establishes a unified standard for the entire process of accounting. The unified power supply benchmark and accounting boundary are determined as follows:

[0065] Based on three core information categories—basic information of coal-fired power units, BECCS retrofit technology solutions, and basic accounting requirements—accounting boundaries covering the entire life cycle of raw coal and biomass, boiler combustion, power generation, and the entire process of carbon capture, transportation, and storage are defined.

[0066] It also establishes a unified power supply benchmark E that is shared by the baseline pure coal working condition and the BECCS scenario, and clarifies the accounting cycle and the data caliber specifications for the entire process.

[0067] The unified power supply benchmark E established above will serve as the core benchmark for subsequent combustion emission accounting and efficiency loss accounting, while the accounting boundaries and data caliber will provide a clear scope basis for the entire process of data collection.

[0068] In this embodiment, the general core symbols involved in the following calculation process are explained in Table 1.

[0069] Table 1 General Core Symbols

[0070]

[0071] In this embodiment, the baseline emissions are: the total life-cycle carbon emissions from pure coal combustion.

[0072] The core function of this step is to establish a benchmark for assessing the emission reduction effectiveness of the BECCS scenario. The process for determining the benchmark emissions is as follows:

[0073] Using the predetermined unified power supply benchmark E and the accounting boundary as the core benchmarks, and based on the raw coal basic parameters, emission factor set, raw coal supply chain parameters and unit power consumption parameters in the full-chain accounting basic dataset, benchmark intermediate quantity one, benchmark intermediate quantity two and benchmark intermediate quantity three are calculated in sequence; among them, benchmark intermediate quantity one is the fossil source CO2 emission generated by the pure coal combustion at the benchmark line, benchmark intermediate quantity two is the carbon emission of the entire process of raw coal mining, washing and transportation, and benchmark intermediate quantity three is the carbon emission generated by the auxiliary energy consumption of conventional plant power consumption.

[0074] Add the values ​​of benchmark intermediate quantity one, benchmark intermediate quantity two, and benchmark intermediate quantity three together to obtain the benchmark emission quantity. Simultaneously output baseline emissions The power supply efficiency of the unit ;in It will serve as the core benchmark for the final net carbon emissions calculation. This provides key input parameters for subsequent calculation of additional emissions due to power generation efficiency losses. Baseline emissions The expression is:

[0075]

[0076] In the formula, The baseline is the total carbon emissions over the entire life cycle, i.e., the baseline emissions, expressed in tCO2. This is the total raw coal consumption corresponding to the same power supply within the accounting period under the baseline pure coal operating condition, in tons. Under the baseline pure coal operating condition, the total amount of conventional plant power consumption of the unit corresponding to the same power supply within the accounting period is expressed in MWh.

[0077] The baseline emissions are the total life-cycle carbon emissions under pure coal operating conditions, with the same uniform power supply E as a benchmark. This value itself does not directly participate in the calculation of the first to sixth carbon emissions; however, the unit power supply efficiency η0, which is output synchronously in the baseline calculation, will serve as a key input parameter for the fourth carbon emission (additional power generation efficiency loss). The baseline emissions are ultimately used in step S3 as a benchmark for emission reduction effects, used to calculate the total carbon emission reduction ΔQ and the comprehensive carbon emission reduction rate η under the BECCS scenario relative to the pure coal operating conditions. reduction .

[0078] In this embodiment, the first carbon emission is the BECCS scenario combustion emission.

[0079] The BECCS scenario-based combustion emissions calculation uses a predetermined unified power supply baseline E and calculation boundary as the core benchmarks. Based on fundamental data such as raw coal and biomass fuel parameters and biomass blending ratio parameters from the full-chain accounting basic dataset, it calculates fossil source CO2 emissions. CO2 emissions from biomass sources Among them, fossil-derived CO2 emissions The figures represent fossil-source CO2 emissions and biomass-source CO2 emissions from the combustion of surplus raw coal under the BECCS scenario. This refers to the CO2 emissions from biomass co-firing and combustion.

[0080] The output of this stage This data will be used for subsequent emission accounting of the capture system and the summary of net emissions across the entire chain. The total theoretical capture amount of the two types of CO2 will provide core data support for the accounting of leakage emissions from the capture system and the calculation of the total net CO2 storage.

[0081]

[0082] in,

[0083]

[0084] In the formula, This represents the fossil-source CO2 emissions from the combustion of residual raw coal under the BECCS scenario, expressed in tCO2. This refers to the CO2 emissions from biomass combustion under the BECCS scenario, expressed in tCO2.

[0085] In this embodiment, the second carbon emission: carbon emissions throughout the entire life cycle of biomass supply.

[0086] The entire life-cycle carbon emission accounting of the biomass and raw coal supply chain, with the biomass supply carbon emission accounting segment covering three main biomass sources: agricultural waste, forestry waste, and energy crops. The process for determining the second carbon emission level is as follows:

[0087] Based on the biomass consumption, supply chain parameters, emission factor set, and agricultural input application data in the whole-chain accounting basic dataset, the carbon emissions of the biomass production and collection stage, the carbon emissions of the long-distance transportation stage, and the carbon emissions of the crushing and molding pretreatment stage are calculated in sequence.

[0088] The second carbon emission figure is obtained by summing the carbon emissions from the biomass production and collection process, the carbon emissions from the long-distance transportation process, and the carbon emissions from the crushing and pre-treatment process. Second carbon emissions The expression is:

[0089]

[0090] In the formula, Total carbon emissions for the entire biomass supply chain (production / collection, transportation, pretreatment), expressed in tCO2. The total carbon emissions from the production / collection of agricultural waste used in co-firing, expressed in tCO2. The total carbon emissions from the collection of forestry waste used in co-firing are expressed in tCO2. The total carbon emissions from the production / collection of energy crops used in co-firing, expressed in tCO2. The total transportation distance of biomass from the production site to the power plant, in km; The proportion of the l-th mode of transportation to the total transportation distance of biomass is dimensionless. The retention ratio after biomass pretreatment refers to the proportion of biomass mass that can be used for co-firing after pretreatment to the total mass before pretreatment, and is dimensionless. The amount of the j-th type of fuel consumed per unit of pre-treated biomass, in t / t biomass; Let be the carbon emission factor of the j-th fuel, expressed in tCO2 / GJ. The power consumption per unit of biomass grinding and drying process is expressed in MWh / t biomass. The electricity consumption per unit of biomass pelleting process is expressed in MWh / t biomass.

[0091] The complete collection and emission data from agricultural / forestry / energy crop production is as follows:

[0092]

[0093] In the formula, The amount of nitrogen fertilizer applied during the production of agricultural waste is expressed in tons (t). The carbon emission factor per unit of nitrogen fertilizer production is expressed in tCO2 / t. The amount of phosphate fertilizer applied during the production of agricultural waste is expressed in tons (t). The carbon emission factor per unit of phosphate fertilizer production is expressed in tCO2 / t. The amount of potassium fertilizer applied during the production of agricultural waste is expressed in tons (t). The carbon emission factor per unit of potash fertilizer production is expressed in tCO2 / t. The total amount of inorganic nitrogen fertilizer applied during the growth period of agricultural waste is expressed in tN. The total amount of organic nitrogen fertilizer applied during the growth period of agricultural waste is expressed in tons (tN). The IPCC recommended direct N2O emission factor for farmland soil, dimensionless; The global warming potential (GWP) of N2O over the IPCCAR 6100-year timescale is used to convert N2O into CO2 equivalents and is dimensionless. The ratio of nitrogen volatilized in the form of NH3 / NOx from inorganic nitrogen fertilizer is dimensionless. The ratio of nitrogen volatilized from organic nitrogen fertilizer in the form of NH3 / NOx is dimensionless; 0.01 is the IPCC recommended N2O emission factor for nitrogen atmospheric deposition from soil and water surface, dimensionless. For areas where leaching / runoff occurs, the proportion of nitrogen lost through leaching and runoff in the managed soil relative to the total nitrogen application is dimensionless. The N2O emission factor recommended by the IPCC for nitrogen leaching / runoff is dimensionless; The total mass of agricultural waste used for co-firing, expressed in tons; Electricity purchased for agricultural waste collection, measured in MWh;

[0094]

[0095] In the formula, The total mass of forestry waste used for co-firing, expressed in tons (t). The electricity purchased for the collection of forestry waste is expressed in MWh / t of forestry waste.

[0096]

[0097] In the formula, The total mass of energy crops used for co-firing, expressed in tons; The amount of seed consumed per unit of energy crop, expressed in t / t of energy crop. Carbon emission factor per unit of seed production, expressed in tCO2 / t; The herbicide consumption is per unit of energy crop, expressed in t / t of energy crop. Carbon emission factor per unit of herbicide production, expressed in tCO2 / t; The amount of nitrogen fertilizer applied during the production of agricultural waste is expressed in tons (t). The carbon emission factor per unit of nitrogen fertilizer production is expressed in tCO2 / t. The amount of phosphate fertilizer applied during the production of agricultural waste is expressed in tons (t). The carbon emission factor per unit of phosphate fertilizer production is expressed in tCO2 / t. The amount of potassium fertilizer applied during the production of agricultural waste is expressed in tons (t). The carbon emission factor per unit of potash fertilizer production is expressed in tCO2 / t. This represents the total greenhouse gas emissions from direct N2O emissions during energy crop production, expressed in tCO2. This represents the total greenhouse gas emissions from indirect N2O emissions during energy crop production, expressed in tCO2. The CO2 equivalent emissions from land use change resulting from planting 1 t of energy crops are expressed as tCO2e / t energy crops. Carbon emissions from fuel combustion during the production / collection of energy crops, expressed in tCO2. This refers to the carbon emissions generated from purchased electricity during the production / collection of energy crops, expressed in tCO2.

[0098] In this embodiment, the third carbon emission: carbon emissions from raw coal supply under the BECCS scenario.

[0099] The carbon emission accounting for raw coal supply targets the blended surplus raw coal under the BECCS scenario. Specifically, based on the raw coal consumption, mining and washing parameters, transportation parameters, and corresponding emission factors in the full-chain accounting dataset, it calculates the third carbon emissions from the raw coal mining, washing, and transportation stages. Third carbon emissions The expression is:

[0100]

[0101] In the formula, This represents the total carbon emissions from the entire supply chain of surplus raw coal under the BECCS scenario, i.e., the third carbon emissions, expressed in tCO2.

[0102] In this embodiment, the fourth carbon emission: carbon emissions additional due to power generation efficiency loss.

[0103] Based on a predetermined uniform power supply standard E, and according to the biomass calorific value blending ratio... BECCS scenario unit power supply efficiency Fuel base parameters, and baseline power supply efficiency of the preceding output. The additional carbon emissions from fossil sources resulting from the extra raw coal consumption due to efficiency losses are calculated separately. The additional carbon emissions from biomass sources resulting from extra biomass consumption are ultimately summed up to obtain the total additional carbon emissions due to power generation efficiency losses. Among them, fossil sources add carbon emissions It will be included in the total net carbon emissions calculation across the entire chain.

[0104] The expression for the fourth carbon emission is:

[0105] ;

[0106] in, The total additional carbon emissions resulting from power generation efficiency losses; The fossil-source carbon emissions resulting from the additional consumption of raw coal due to efficiency losses, i.e., the fourth carbon emission, are measured in tCO2. Carbon emissions from biomass sources resulting from additional biomass consumption due to efficiency losses, expressed in tons of CO2 (tCO2); E is a uniform electricity supply benchmark. The calorific value of biomass fuels and the blending ratio under the BECCS scenario. For the unit power supply efficiency under the BECCS scenario, The power supply efficiency of the unit under the baseline pure coal operating condition is used as a reference. The lower heating value of raw coal is the base calorific value. The carbon content per unit of calorific value of raw coal. The carbon oxidation rate of raw coal refers to the mass ratio of carbon elements oxidized to CO2 during the combustion of raw coal to the total carbon content. For biomass to receive lower heating value, The carbon content per unit of calorific value of biomass. The carbon oxidation rate of biomass.

[0107] Existing technologies have never so explicitly decomposed efficiency penalties into fossil and biomass sources and precisely correlated them with uniform power output E and calorific value blending ratio λ. The formula in this invention directly transforms an engineering problem (efficiency reduction leading to increased fuel consumption) into a calculable emission item, which is key to overcoming the shortcomings of oversimplified efficiency changes.

[0108] In this embodiment, the fifth carbon emission: the total carbon emissions of the CO2 capture system.

[0109] Based on the CCS capture system operating parameters, emission factor set, solvent replenishment amount and related parameters in the full-chain accounting basic dataset, the fifth carbon emission amount one, the fifth carbon emission amount two, and the fifth carbon emission amount three are calculated sequentially. Among them, the fifth carbon emission amount one is the carbon emission amount generated by the auxiliary power consumption of the capture system, the fifth carbon emission amount two is the carbon emission amount generated by the solvent reheat consumption, and the fifth carbon emission amount three is the carbon emission amount of the capture solvent production and replenishment process.

[0110] The values ​​of Fifth Carbon Emissions I, Fifth Carbon Emissions II, and Fifth Carbon Emissions III are summed to obtain the Fifth Carbon Emissions. ;

[0111] The above is the fifth carbon emission. It will be included in the total net emissions of the entire chain.

[0112] Fifth carbon emissions The expression is:

[0113]

[0114] In the formula, The total carbon emissions of the entire CO2 capture system, also known as the fifth carbon emission, are expressed in tCO2. The total power consumption of the CO2 capture system during the accounting period is expressed in MWh. The total heat consumption for solvent regeneration in the CO2 capture system during the accounting cycle is expressed in GJ. The amount of solvent replenished to the CO2 capture system during the accounting period, in tons; The carbon emission factor per unit of captured solvent production is expressed in tCO2 / t.

[0115] Simultaneously, the theoretically survivable total CO2 from fossil sources and biomass sources is calculated. Based on these two figures, and the CO2 leakage rate of the CO2 capture system, the CO2 negative emission offset is calculated. , This provides core data for subsequent transportation and storage accounting and final negative emission deduction.

[0116]

[0117]

[0118]

[0119] The theoretical total amount of CO2 that can be captured from fossil sources is expressed in tCO2. This represents the theoretically achievable total CO2 capture from biomass sources, expressed in tCO2. The actual capture rate of fossil CO2 by the CO2 capture system refers to the proportion of fossil CO2 captured to the total amount of fossil CO2 produced by combustion. The actual capture rate of CO2 from biomass sources by the CO2 capture system refers to the proportion of CO2 captured from biomass sources to the total amount of CO2 produced from the combustion of biomass sources. The CO2 leakage rate of a CO2 capture system refers to the proportion of CO2 leaked from pipelines, storage tanks, valves, and other components during the capture process to the total amount of CO2 captured.

[0120] This refers to the net total amount of CO2 entering the transportation and storage stages during the accounting period (after deducting leakage after capture), which is the negative CO2 emission offset amount, in tCO2.

[0121] The above net total CO2 The design explicitly distinguishes between fossil source capture rates. and system leakage rate Furthermore, it correctly considered all biomass CO2 as theoretically captureable and accurately calculated the net sequestration volume that could actually be used to offset negative emissions.

[0122] In this embodiment, the sixth carbon emission: CO2 transport and storage carbon emissions.

[0123] Based on the CO2 transportation and storage parameters, corresponding emission factor sets, transportation distance and mode parameters, energy consumption parameters in the storage stage, and CO2 negative emission deduction amount in the full-chain accounting basic dataset. The carbon emissions generated by energy consumption in the CO2 transportation process, the leakage emissions in the transportation and geological storage processes, and the carbon emissions generated by auxiliary energy consumption in the storage process are calculated in sequence.

[0124] The sixth carbon emission figure is obtained by summing up the carbon emissions from energy consumption during CO2 transportation, the leakage emissions during transportation and geological storage, and the carbon emissions from auxiliary energy consumption during storage. This result will be included in the final net carbon emissions total across the entire chain.

[0125] The expression for the sixth carbon emission is:

[0126]

[0127] In the formula, The total carbon emissions from the entire process of CO2 transportation and storage, also known as the sixth carbon emission, are expressed in tCO2. This represents the total transportation distance of CO2 from the power plant to the storage site, in km; The carbon emission factor per unit CO2 per unit distance transported is given by transport mode (tanker, pipeline, ship) and is expressed in tCO2 / (t·km). Leakage rate during CO2 transportation; This refers to the long-term leakage rate in the CO2 geological storage process; The total power consumption for CO2 storage during the accounting period is expressed in MWh. The total heat consumption for CO2 sequestration during the accounting period is expressed in GJ.

[0128] S3, based on the baseline emissions, calculates the net carbon emissions over the entire life cycle of the BECCS scenario based on the first, second, third, fourth, fifth, and sixth carbon emissions and the negative CO2 emission credit.

[0129] Step S3 integrates the output results of all preceding steps, including baseline emissions. fossil-derived CO2 emissions Second carbon emissions Third carbon emissions Fourth carbon emissions Fifth carbon emissions Sixth carbon emissions and net total CO2 ,first This is used as a deduction for negative CO2 emissions, accurately characterizing the negative emission characteristics of BECCS technology, and calculating the net carbon emissions throughout the entire life cycle of the BECCS scenario. Then, based on the baseline total carbon emissions, the total carbon emission reduction ΔQ and the comprehensive carbon emission reduction rate η of the BECCS scenario relative to the pure coal operating condition are calculated. reduction Furthermore, the formula for calculating net carbon emissions is:

[0130] ;

[0131] in, Net carbon emissions For fossil-source CO2 emissions, This is the second largest source of carbon emissions. It is the third largest source of carbon emissions. It is the fourth largest carbon emission source. It is the fifth largest carbon emission source. It is the sixth largest carbon emission. This is a deduction amount for negative CO2 emissions.

[0132] Furthermore, the formula for calculating the total carbon emission reduction ΔQ is as follows:

[0133]

[0134] Furthermore, the overall carbon emission reduction rate η reduction The calculation formula is as follows:

[0135]

[0136] The above formula sums up the net carbon emissions, which will include the net total CO2. This is deducted as a negative item, thus mathematically demonstrating the net negative emissions characteristic of BECCS. This is one of the most fundamental differences from any non-CCUS accounting method.

[0137] This invention provides a method for calculating carbon emissions and carbon reductions for biomass-co-fired power units coupled with carbon capture and storage (CCS) technology. This method is based on a unified power supply benchmark and introduces efficiency correction to improve the accuracy and comparability of the calculated carbon emissions and carbon reductions, thereby enhancing its practical industrial application value.

[0138] Example 2

[0139] like Figure 2As shown, the difference between this embodiment and Embodiment 1 is that this embodiment provides a carbon emission accounting system for coal-fired power units oriented towards BECCS, which corresponds one-to-one with the carbon emission accounting method for coal-fired power units oriented towards BECCS in Embodiment 1; the system includes:

[0140] The acquisition unit is used to acquire the basic dataset for full-chain accounting. The basic dataset for full-chain accounting includes fuel basic parameters, emission factor parameters, coal-fired unit operating parameters, supply chain parameters, and CCS system parameters, etc.

[0141] The first calculation unit is used to determine the baseline emissions corresponding to the entire life cycle of pure coal combustion baseline, the first carbon emissions corresponding to the combustion emissions in the BECCS scenario, the second carbon emissions corresponding to the entire life cycle of biomass supply, the third carbon emissions corresponding to the raw coal supply chain in the BECCS scenario, the fourth carbon emissions corresponding to the additional emissions from power generation efficiency loss, the fifth carbon emissions corresponding to the entire CO2 capture system, and the sixth carbon emissions corresponding to the CO2 transportation and storage, based on the full-chain accounting basic dataset and with a predetermined unified power supply benchmark and accounting boundary as the core benchmark.

[0142] The second calculation unit is used to calculate the net carbon emissions over the entire life cycle of the BECCS scenario based on the first carbon emissions, the second carbon emissions, the third carbon emissions, the fourth carbon emissions, the fifth carbon emissions, the sixth carbon emissions, and the negative CO2 emission deduction.

[0143] The execution process of each unit can be carried out according to the carbon emission accounting method for coal-fired power units oriented to BECCS in Example 1, and will not be described in detail in this example.

[0144] Meanwhile, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-mentioned carbon emission accounting method for coal-fired power units oriented towards BECCS.

[0145] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A carbon emission accounting method for coal-fired power units oriented towards BECCS, characterized in that, The method includes: Obtain the full-chain accounting basic dataset, which includes fuel basic parameters, emission factor parameters, coal-fired unit operating parameters, supply chain parameters, and CCS system parameters; Based on the full-chain accounting dataset, and with the predetermined unified power supply benchmark and accounting boundary as the core benchmark, the following are determined: the benchmark emissions corresponding to the entire life cycle of pure coal combustion, the first carbon emissions corresponding to the combustion emissions in the BECCS scenario, the second carbon emissions corresponding to the entire life cycle of biomass supply, the third carbon emissions corresponding to the raw coal supply chain in the BECCS scenario, the fourth carbon emissions corresponding to the additional emissions from power generation efficiency loss, the fifth carbon emissions corresponding to the entire CO2 capture system, and the sixth carbon emissions corresponding to the CO2 transportation and storage. Based on the first carbon emissions, the second carbon emissions, the third carbon emissions, the fourth carbon emissions, the fifth carbon emissions, the sixth carbon emissions, and the negative CO2 emission offset, calculate the net carbon emissions over the entire life cycle of the BECCS scenario.

2. The carbon emission accounting method for coal-fired power units oriented towards BECCS according to claim 1, characterized in that, The process for determining the baseline emissions is as follows: Using the predetermined unified power supply benchmark and accounting boundary as the core benchmark, and based on the raw coal basic parameters, emission factor set, raw coal supply chain parameters and unit plant power parameters in the full-chain accounting basic dataset, the benchmark intermediate quantity one, benchmark intermediate quantity two and benchmark intermediate quantity three are calculated in sequence. The values ​​of the first, second, and third reference intermediate quantities are added together to obtain the reference emission quantity; at the same time, the unit power supply efficiency under the reference emission quantity is output. Among them, the first benchmark intermediate quantity is the fossil source CO2 emission generated by the combustion of pure coal at the baseline, the second benchmark intermediate quantity is the carbon emission of the entire process of raw coal mining, washing and transportation, and the third benchmark intermediate quantity is the carbon emission generated by the auxiliary energy consumption of conventional plant power.

3. The carbon emission accounting method for coal-fired power units oriented towards BECCS according to claim 1, characterized in that, The process for determining the first carbon emission amount is as follows: Using the predetermined unified power supply benchmark and accounting boundary as the core benchmark, and based on the parameters of raw coal and biomass fuel, biomass blending ratio and CO2 capture rate in the full-chain accounting basic dataset, the CO2 emissions from fossil sources and CO2 emissions from biomass sources are calculated. Wherein, the fossil source CO2 emissions are the fossil source CO2 emissions generated by the combustion of residual raw coal under the BECCS scenario, and the biomass source CO2 emissions are the biomass source CO2 emissions generated by the combustion of biomass.

4. The carbon emission accounting method for coal-fired power units oriented towards BECCS according to claim 1, characterized in that, The process for determining the second and third carbon emissions is as follows: Based on the biomass consumption, supply chain parameters, emission factor set and agricultural input application data in the whole chain accounting basic dataset, the carbon emissions of biomass production and collection, long-distance transportation, and crushing and pre-treatment are calculated in sequence. The carbon emissions from the biomass production and collection process, the long-distance transportation process, and the crushing and pre-treatment process are combined to obtain the second carbon emission. The process for determining the third carbon emission is as follows: Based on the raw coal consumption, mining and washing parameters, transportation parameters and corresponding emission factors in the full-chain accounting basic dataset, the third carbon emissions of raw coal mining, washing and transportation are calculated.

5. The carbon emission accounting method for coal-fired power units oriented towards BECCS according to claim 1, characterized in that, The expression for the fourth carbon emission is: ； in, The total additional carbon emissions resulting from power generation efficiency loss. The fossil-source carbon emissions resulting from the additional consumption of raw coal due to efficiency losses, i.e., the fourth carbon emissions; E represents the carbon emissions from biomass sources resulting from additional biomass consumption due to efficiency losses, with E serving as a uniform power supply benchmark. The calorific value of biomass fuels and the blending ratio under the BECCS scenario. For the unit power supply efficiency under the BECCS scenario, The power supply efficiency of the unit under the baseline pure coal operating condition is used as a reference. The lower heating value of raw coal is the base calorific value. The carbon content per unit of calorific value of raw coal. The carbon oxidation rate of raw coal refers to the mass ratio of carbon elements oxidized to CO2 during the combustion of raw coal to the total carbon content. For biomass to receive lower heating value, The carbon content per unit of calorific value of biomass. The carbon oxidation rate of biomass.

6. The carbon emission accounting method for coal-fired power units oriented towards BECCS according to claim 1, characterized in that, The process for determining the fifth carbon emission is as follows: Based on the carbon capture system operating parameters, emission factor set, solvent replenishment amount and related parameters in the full-chain accounting basic dataset, the fifth carbon emission first, fifth carbon emission second and fifth carbon emission third are calculated in sequence; Add the fifth carbon emission one, the fifth carbon emission two, and the fifth carbon emission three together to obtain the fifth carbon emission; Among them, the fifth carbon emission one is the carbon emission generated by the auxiliary power consumption of the capture system, the fifth carbon emission two is the carbon emission generated by the solvent reheat consumption, and the fifth carbon emission three is the carbon emission generated by the production and replenishment of capture solvent. Simultaneously, the theoretical total captureable amount of CO2 from fossil sources and the theoretical total captureable amount of CO2 from biomass sources are calculated; and based on the theoretical total captureable amount of CO2 from fossil sources, the theoretical total captureable amount of CO2 from biomass sources, and the CO2 leakage rate of the CO2 capture system, the CO2 negative emission offset amount is calculated.

7. The carbon emission accounting method for coal-fired power units oriented towards BECCS according to claim 3, characterized in that, The process for determining the sixth carbon emission is as follows: Based on the parameters of CO2 transportation and storage, the corresponding emission factor set, transportation distance and transportation mode parameters, energy consumption parameters of storage, and the negative CO2 emission deduction amount in the full-chain accounting basic dataset, the carbon emissions generated by energy consumption in CO2 transportation, the leakage emissions in transportation and geological storage, and the carbon emissions generated by auxiliary energy consumption in storage are calculated in sequence. The sixth carbon emission is obtained by summing up the carbon emissions generated by energy consumption in the CO2 transportation process, the leakage emissions in the transportation and geological storage process, and the carbon emissions generated by auxiliary energy consumption in the storage process.

8. The carbon emission accounting method for coal-fired power units oriented towards BECCS according to claim 1, characterized in that, The formula for calculating net carbon emissions is as follows: ； in, Net carbon emissions For fossil-source CO2 emissions, This is the second largest source of carbon emissions. It is the third largest source of carbon emissions. It is the fourth largest carbon emission source. It is the fifth largest carbon emission source. It is the sixth largest carbon emission. This is a deduction amount for negative CO2 emissions.

9. A carbon emission accounting system for coal-fired power units oriented towards BECCS, characterized in that, The system includes: The acquisition unit is used to acquire the full-chain accounting basic dataset, which includes fuel basic parameters, emission factor parameters, coal-fired unit operating parameters, supply chain parameters and CCS system parameters; The first calculation unit is used to determine the baseline emissions corresponding to the entire life cycle of pure coal combustion baseline, the first carbon emissions corresponding to the combustion emissions in the BECCS scenario, the second carbon emissions corresponding to the entire life cycle of biomass supply, the third carbon emissions corresponding to the raw coal supply chain in the BECCS scenario, the fourth carbon emissions corresponding to the additional emissions from power generation efficiency loss, the fifth carbon emissions corresponding to the entire CO2 capture system, and the sixth carbon emissions corresponding to the CO2 transportation and storage, based on the full-chain accounting basic dataset and with a predetermined unified power supply benchmark and accounting boundary as the core benchmark. The second calculation unit is used to calculate the net carbon emissions over the entire life cycle of the BECCS scenario based on the first carbon emissions, the second carbon emissions, the third carbon emissions, the fourth carbon emissions, the fifth carbon emissions, the sixth carbon emissions, and the negative CO2 emission offset.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the carbon emission accounting method for coal-fired power units oriented towards BECCS as described in any one of claims 1 to 8.

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