Carbon footprint calculation method of coal-fired power product

Abstract

The invention discloses a method for calculating a carbon footprint of a coal-fired power product. The method comprises the following steps of: 1, determining a system boundary of the carbon footprint in a life cycle of the coal-fired power product; 2, dividing the carbon footprint into a raw material acquisition stage, a transportation stage and an operation power generation stage in the system boundary; 3, greenhouse gas emission factors in the raw material obtaining stage, the transportation stage and the operation power generation stage are determined respectively, and a carbon emission formula is constructed; 4, obtaining the carbon footprint of the coal-fired power product through the carbon emission formula of each stage; according to the method, greenhouse gas emission generated by the coal-fired power product in the whole life cycle can be comprehensively quantified, the carbon footprint in the coal-fired power product is accurately calculated, and carbon emission intensity evaluation is provided for different coal-fired power generation enterprises; therefore, solid data support and decision basis are provided for carbon emission reduction strategic planning in the power industry and even related industrial fields.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation and emission reduction measurement and evaluation methods, in particular to the technical field of carbon footprint calculation. Background Art

[0003] At present, the boundary demarcation of the carbon footprint of coal-fired power generation in the industry is not comprehensive. Most of the research contents focus on the environmental impact of a certain stage or a certain category of coal-fired power generation, which leads to insufficient demarcation of boundaries and inventory completeness, and the lack of credibility of the results. For example, Wang Siyi (Carbon Footprint and Economic Cost Evaluation of Power Generation Enterprises from the Perspective of Resource Value Stream: Comparative Study of Coal-fired Power Generation and Biomass Power Generation [J]. Industrial Technology and Economy, 2018, 37(12): 78- 85.) et al. failed to fully consider the boundaries when conducting carbon footprint analysis of the life cycle of coal-fired power generation, especially the coal mining and processing stages. They only took electricity consumption into consideration and failed to fully reflect the carbon footprint of the entire upstream process. Similarly, Jia Yalei (Environmental Load Analysis of Wind Power Generation, Photovoltaic Power Generation and Coal-fired Power Generation Based on LCA [J]. Journal of Power Engineering, 2016, 36(12): 1000-1009.) When conducting life cycle assessments on the environmental impacts of different power generation methods, although the boundary setting for coal-fired power generation was relatively comprehensive, the impact of upstream links was also ignored in the inventory analysis; the limitations of these studies show that in order to improve the comprehensiveness and accuracy of the assessment, a detailed and comprehensive examination of the entire life cycle of coal-fired power generation products must be conducted.

[0004] Coal-fired units are the core equipment in the power production system and the main source of carbon emissions from coal-fired power products. Quantifying the greenhouse gas emissions of coal-fired units and rating the carbon emission intensity based on these data can not only enable coal-fired power generation companies to have a clear understanding of carbon emissions during coal combustion and clarify their own emission reduction responsibilities, but also provide data support for the carbon emission reduction strategy planning of the power industry and even related industrial fields. However, the industry currently lacks a method to rate the carbon emission intensity of coal-fired units. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art and propose a method for calculating the carbon footprint of coal-fired power products, which can comprehensively quantify the greenhouse gas emissions generated by coal-fired power products throughout their entire life cycle, accurately calculate the carbon footprint of coal-fired power products, and provide carbon emission intensity assessment for different coal-fired power generation companies, thereby providing solid data support and decision-making basis for the carbon emission reduction strategic planning of the power industry and even related industrial fields (to facilitate their in-depth exploration of emission reduction potential).

[0006] To achieve the above objectives, the present invention proposes a method for calculating the carbon footprint of coal-fired power products, comprising the following steps: Step 1: Determine the system boundary of the carbon footprint within the life cycle of coal-fired power products; Step 2: Divide the carbon footprint into the raw material acquisition stage, transportation stage, and operation and power generation stage within the system boundary; Step 3, determine the greenhouse gas emission factors in the raw material acquisition stage, transportation stage and power generation stage respectively and construct a carbon emission formula; Step 4: Obtain the carbon footprint of coal-fired power products through the carbon emission formula for each stage.

[0007] Preferably, the carbon footprint of the raw material acquisition stage is quantified using formula (1); (1); In formula (1), E 原料输入, i is the greenhouse gas emissions generated by all raw material inputs in unit process i; AD 原料, i, j is the consumption of the jth raw material in unit process i; EF 原料, i, j is the greenhouse gas emission factor of the jth raw material in unit process i; in addition, E 原料输入,i The unit is tons of carbon dioxide equivalent (tCO2e), AD 原料,i,j The unit is tons (t), EF 原料,i,j The unit is tons of carbon dioxide equivalent / ton (tCO2e / t).

[0008] Preferably, the carbon footprint of the transportation stage is quantified using formula (2); (2); In formula (2), E 物料设备, i M is the greenhouse gas emissions generated by the transportation of the i-th material and equipment; i is the consumption of the i-th material equipment; D i is the average transportation distance of the i-th material equipment; T i is the greenhouse gas emission factor per unit weight of the transport distance of the i-th material equipment; in addition, E 物料设备,i The unit is kgCO2e, M i The unit is t, D i The unit is kilometer (km), T i The unit is kilograms of carbon dioxide equivalent per tonne-kilometer (kgCO2e / t·km).

[0009] Preferably, the carbon footprint of the power generation phase is quantified using formula (3); (3); In formula (3), E i, j AD is the greenhouse gas emissions from the jth emission source in unit process i;i, j, p EF is the activity level data of p greenhouse gases emitted by the jth emission source in unit process i; i, j, p is the greenhouse gas emission factor of p greenhouse gases emitted by the jth emission source in unit process i; GWP p is the global warming potential of p greenhouse gases; in addition, E i，j The unit is kilograms of carbon dioxide equivalent (kgCO2e); EF i,j,p The electricity greenhouse gas emission factor used should be the electricity life cycle carbon footprint factor.

[0010] Preferably, the emission sources include three categories, namely fuel combustion, input energy and production process.

[0011] As a preference, GWP p The GWP value in the latest IPCC Climate Assessment Report (AR) is used.

[0012] Preferably, the carbon emission intensity is also calculated in step 4, and the carbon emission intensity of the coal-fired unit is calculated using formula (4) during the power generation phase (i.e., the annual carbon dioxide emissions can be calculated according to formula (4)); (4); In formula (4), T is the annual carbon dioxide emissions of a single coal-fired power generation unit (t CO2eq); U c is the installed capacity of the unit (MW); h is the annual average operating hours (h); γ is the load factor; ζ is the standard coal consumption (gce / (kWh)); η is the carbon dioxide emission factor of standard coal.

[0013] As a preferred method, a carbon emission rating standard is formulated according to the carbon emission intensity of coal-fired units, and a three-level system is used to rate the carbon emissions of coal-fired power generation enterprises. 8 kg CO2eq as level I, with 1.586×10 8 kg CO2eq ≤Carbon emission intensity of coal-fired units≤3.12×10 8 kg CO2eq as level II, with the carbon emission intensity of coal-fired units>3.12×10 8 kg CO2eq as level III.

[0014] Preferably, the raw material acquisition stage includes the supply of building materials and machinery and equipment, the mining and processing of coal, and the supply of energy, water and auxiliary materials; the transportation stage includes the transportation of building materials and machinery and equipment and the transportation of coal; and the operation and power generation stage includes the power plant construction stage, the operation and power generation stage and the power grid connection stage.

[0015] Beneficial effects of the present invention: In view of the problems in the prior art of incomplete system boundary division in the carbon footprint calculation process of coal-fired power products (insufficient inventory completeness), lack of effective evaluation method for carbon emission intensity rating of units of different capacities, and lack of carbon footprint quantification model for each stage of coal-fired power products, the present invention establishes a carbon footprint model calculation method for the entire life cycle of coal-fired power generation according to the entire life cycle process of coal-fired power generation. The carbon footprint of the raw material acquisition stage, transportation stage and operation power generation stage of coal-fired power generation can be quantified (the entire life cycle of coal-fired power products is scientifically divided), thereby standardizing the calculation method of the carbon footprint of each stage, laying the foundation for carbon footprint calculation in the coal-fired power generation industry; at the same time, the present application adopts a combination of qualitative and quantitative methods, and by accurately setting different levels of carbon emission intensity evaluation indexes, it can achieve a scientific evaluation of the carbon emissions of coal-fired power generation enterprises.

[0016] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the system boundary diagram for the life cycle adjustment of coal-fired power products; Figure 2 It is an overview of emissions over the entire life cycle of coal-fired power generation. DETAILED DESCRIPTION

[0018] See also Figure 1 The method for calculating the carbon footprint of coal-fired power products of the present invention comprises the following steps: Step 1: Determine the system boundary of the carbon footprint during the life cycle of coal-fired power products; The system boundary of the complete life cycle of coal-fired power products is determined, that is, from the starting point of its original resource extraction (the "cradle") to the threshold (the "gate") where electricity is produced and ready to enter the grid; this scope covers upstream supply chain activities and core production stages; Step 2: Divide the carbon footprint into the raw material acquisition stage, the transportation stage and the operation and power generation stage within the system boundary; the raw material acquisition stage includes the supply of building materials and machinery and equipment, the coal mining and processing and fine washing stage, and the supply of energy, water and auxiliary materials; the transportation stage includes the transportation of building materials and machinery and equipment and the transportation of coal; the operation and power generation stage includes the power plant construction stage, the operation and power generation stage and the power grid connection stage; The specific breakdown of the raw material acquisition stage is as follows: a) Supply of building materials and machinery and equipment: This process begins with the extraction of natural resources, which are then converted into building materials (such as steel, cement, wood, plastic, insulation materials and glass) and specialized machinery and equipment required for power generation (including power generation units, auxiliary machinery and environmental protection equipment). This process also includes the maintenance of production facilities and the effective management of waste; b) Coal mining and processing and fine washing: The acquisition of coal includes underground and open-pit mining, as well as the greenhouse gases generated during subsequent processing (especially carbon dioxide generated by methane combustion or oxidation, minus the combustion and recovery benefits of methane) are taken into consideration; in addition, equipment maintenance and waste management during coal mining and fine washing also fall into this category; c) Supply of energy, water and auxiliary materials: The collection of auxiliary materials (such as combustion aids, flue gas purifiers, diesel, flocculants, lubricants, hydrochloric acid, limestone, noise reduction materials and filter bags, etc.) and water resources necessary for power generation in power plants constitutes this process; this process also involves the mining and consumption of energy required by building materials production, machinery and equipment manufacturing, coal mining and processing, and auxiliary materials production; The specific breakdown of the operational power generation phase is as follows: a) Power plant construction: This phase not only involves the physical construction and integration of building materials and machinery and equipment components, but also covers the efficient management and resource recovery of waste during construction; b) Operation and power generation: The core of power generation lies in the efficient combustion of fossil fuels in boilers (including startup boilers) and the process of environmental protection equipment such as desulfurization and denitrification systems heating flue gas with additional fossil fuels to purify emissions. In addition, the fossil fuel consumption of auxiliary systems such as emergency diesel generators and mobile equipment is also fully considered in this link; c) Power grid connection: power loss caused by grid connection; Step 3, determine the greenhouse gas emission factors in the raw material acquisition stage, transportation stage and power generation stage respectively and construct a carbon emission formula; Step 4, obtain the carbon footprint of coal-fired power products through the carbon emission formula of each stage; For step 4, the carbon footprint of the raw material acquisition stage is quantified using formula (1); (1); In formula (1), E 原料输入, i is the greenhouse gas emissions generated by all raw material inputs in unit process i; AD 原料, i, j is the consumption of the jth raw material in unit process i; EF 原料, i, j is the greenhouse gas emission factor of the jth raw material in unit process i; in addition, E原料输入,i The unit is tCO2e, AD 原料,i,j The unit is t, EF 原料,i,j The unit is tCO2e / t; quantification in units of carbon dioxide equivalent not only identifies and quantifies the carbon emission reduction potential in the power generation process, but is also crucial for formulating practical emission reduction measures; For step 4, the carbon footprint of the transportation stage is quantified using formula (2); (2); In formula (2), E 物料设备, i M is the greenhouse gas emissions generated by the transportation of the i-th material and equipment; i is the consumption of the i-th material equipment; D i is the average transportation distance of the i-th material equipment; T i is the greenhouse gas emission factor per unit weight of the transport distance of the i-th material equipment; in addition, E 物料设备,i The unit is kgCO2e, M i The unit is t, D i The unit is km, T i The unit is kgCO2e / t·km; For step 4, the carbon footprint of the power generation phase is quantified using formula (3); (3); In formula (3), E i, j AD is the greenhouse gas emissions from the jth emission source in unit process i; i, j, p EF is the activity level data of p greenhouse gases emitted by the jth emission source in unit process i; i, j, p is the greenhouse gas emission factor of p greenhouse gases emitted by the jth emission source in unit process i; GWP p is the global warming potential of p greenhouse gases; in addition, E i，j The unit is kgCO2e; EF i,j,p The electricity greenhouse gas emission factor used should be the electricity life cycle carbon footprint factor; Emission sources include three categories: fuel combustion, energy input and production process; GWP p The GWP value in the latest climate assessment report released by IPCC is used.

[0019] In step 4, the carbon emission intensity is also calculated, and the carbon emission intensity of the coal-fired unit is calculated during the power generation phase using formula (4); (4); In formula (4), T is the annual carbon dioxide emissions of a single coal-fired power generation unit (t CO2eq); U c is the installed capacity of the unit (MW); h is the annual average operating hours (h); γ is the load factor; ζ is the standard coal consumption (gce / (kWh)); η is the carbon dioxide emission factor of standard coal; As shown in Table 1 below, a carbon emission rating standard is formulated based on the carbon emission intensity of coal-fired units, and a three-level system is used to rate the carbon emissions of coal-fired power generation enterprises. The carbon emission intensity of coal-fired units is less than 1.586×10 8 kg CO2eq as level I, with 1.586×10 8 kg CO2eq ≤Carbon emission intensity of coal-fired units≤3.12×10 8 kg CO2eq as level II, with the carbon emission intensity of coal-fired units>3.12×10 8 kg CO2eq as level III.

[0020] Table 1 Carbon emission intensity evaluation index of different levels of coal-fired power generation enterprises

[0021]

[0022] This assessment system adopts a combination of qualitative and quantitative methods, and achieves a scientific assessment of the environmental performance of coal-fired power generation enterprises by accurately setting different levels of carbon emission intensity evaluation indexes; specifically, this assessment system establishes three levels of carbon emission intensity standards (i.e., Level I, Level II, and Level III) based on a detailed assessment quantitative method; these levels are intended to fully reflect the current status of carbon emissions in my country's coal-fired power generation industry and provide clear guidance for enterprises' energy conservation and emission reduction work (carbon emission intensity ratings can provide data support for carbon emission reduction strategic planning in the power industry and even related industrial fields); in addition, the specific meanings of carbon emission rating levels are as follows: The emission intensity evaluation index of level I is set to be less than 1.586×10 8 kg CO2eq, and this standard represents the most advanced carbon emission control level in the industry; companies that meet or exceed this standard will be rated as Level I to demonstrate their outstanding performance in the field of environmental protection; The emission intensity evaluation index of Level II is set at 1.586×10 8 to 3.12×10 8 kg CO2eq, and this range is intended to encourage companies to continuously improve carbon emission control technologies and gradually move towards higher standards; companies that meet the requirements of this range will be rated as Level II, recognizing their positive efforts and achievements in environmental protection; The emission intensity evaluation index of level III is set to be greater than 3.12×108 kg CO2eq, and this standard reflects the current low level of carbon emission control in the industry; enterprises that fail to meet the standards of the first two levels will be assessed as Level III, and are advised to increase environmental protection investment and improve carbon emission control capabilities to achieve energy conservation and emission reduction goals as soon as possible.

[0023] Embodiment 1: The carbon footprint calculation method of the product of the present invention is further supplemented below in combination with actual data; the field data comes from actual measurements during the production process of a coal-fired power plant in Hebei Province; the coal-fired power plant has four condensing cogeneration units of 2×300MW and 2×315MW, as well as a shared set of flue gas treatment equipment, and the coal comes from the Shenhua mining area in Shaanxi Province, my country.

[0024] The total carbon footprint of the on-grid electricity generated by coal-fired power plants in 2022 is 7.4×106 tCO2e. The heat supply ratio of the power plant in this case is 0.244. After allocating the heat and electricity of the electric heat products output by coal-fired power generation based on the heat supply ratio, the carbon footprint per unit of on-grid electricity generated by the entire coal-fired power plant is 0.932 kgCO2e / kWh.

[0025] Table 2 List of on-site data of a coal-fired power plant in Hebei Province

[0026]

[0027] The classification calculation process is as follows: (4); In the formula, T is the annual carbon dioxide emissions of a single coal-fired power generation unit (t CO2eq); U c is the installed capacity of the unit (MW); h is the annual average operating hours (h); γ is the load factor; ζ is the standard coal consumption (gce / (kWh)); η is the carbon dioxide emission factor of standard coal.

[0028]

[0029] Note: The standard coal consumption of 600MW is 294 grams of standard coal per kilowatt-hour; the standard coal consumption of 300MW is 299 grams of standard coal per kilowatt-hour; data source: "Benchmark Levels and Benchmark Levels in Key Areas of Clean and Efficient Utilization of Coal (2022 Edition)".

[0030] So we get: The emission intensity evaluation index of level I is set to be less than 1.586×10 8 kg CO2eq, and this standard represents the most advanced carbon emission control level in the industry; companies that meet or exceed this standard will be rated as Level I to demonstrate their outstanding performance in the field of environmental protection; The emission intensity evaluation index of Level II is set at 1.586×10 8 to 3.12×10 8 kg CO2eq, and this range is intended to encourage companies to continuously improve carbon emission control technologies and gradually move towards higher standards; companies that meet the requirements of this range will be rated as Level II, recognizing their positive efforts and achievements in environmental protection; The emission intensity evaluation index of level III is set to be greater than 3.12×10 8 kg CO2eq, and this standard reflects the current low level of carbon emission control in the industry; enterprises that fail to meet the standards of the first two levels will be assessed as Level III, and are advised to increase environmental protection investment and improve carbon emission control capabilities to achieve energy conservation and emission reduction goals as soon as possible.

[0031] In addition, based on the evaluation results of the emission inventory and carbon footprint, the present invention also conducts a comparative analysis of emissions in the boundary process and obtains an emission profile of the entire life cycle of coal-fired power generation (specifically, Figure 2 Observe Figure 2 It can be found that the carbon emissions of coal-fired power generation products during their life cycle mainly come from direct emissions, accounting for more than 99%, while indirect emissions account for less than 1%; among direct emissions, the power generation operation stage occupies a dominant position, accounting for nearly 80%; as for indirect emissions, the coal supply link contributes the most, accounting for about 88%.

[0032] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. A method for calculating the carbon footprint of coal-fired power products, characterized in that: The steps include: Step 1: Determine the system boundary of the carbon footprint within the life cycle of coal-fired power products; Step 2: Divide the carbon footprint into the raw material acquisition stage, transportation stage, and operation and power generation stage within the system boundary; Step 3, determine the greenhouse gas emission factors in the raw material acquisition stage, transportation stage and power generation stage respectively and construct a carbon emission formula; Step 4: Obtain the carbon footprint of coal-fired power products through the carbon emission formula for each stage.

2. The method for calculating the carbon footprint of coal-fired power products according to claim 1, characterized in that: Formula (1) is used to quantify the carbon footprint of the raw material acquisition stage; （1）； In formula (1), E 原料输入, i is the greenhouse gas emissions generated by all raw material inputs in unit process i; AD 原料, i, j is the consumption of the jth raw material in unit process i; EF 原料, i, j is the greenhouse gas emission factor of the jth raw material in unit process i.

3. The method for calculating the carbon footprint of a coal-fired power product according to claim 1, characterized in that: Formula (2) is used to quantify the carbon footprint of the transportation stage; （2）； In formula (2), E 物料设备, i M is the greenhouse gas emissions generated by the transportation of the i-th material and equipment; i is the consumption of the i-th material equipment; D i is the average transportation distance of the i-th material equipment; T i is the greenhouse gas emission factor per unit weight of the transportation distance of the i-th type of material and equipment.

4. The method for calculating the carbon footprint of a coal-fired power product according to claim 1, characterized in that: Formula (3) is used to quantify the carbon footprint of the power generation phase of operation; （3）； In formula (3), E i, j AD is the greenhouse gas emissions from the jth emission source in unit process i; i, j, p EF is the activity level data of p greenhouse gases emitted by the jth emission source in unit process i; i, j, p is the greenhouse gas emission factor of p greenhouse gases emitted by the jth emission source in unit process i; GWP p is the global warming potential of p greenhouse gases.

5. The method for calculating the carbon footprint of a coal-fired power product according to claim 4, characterized in that: Emission sources include three categories: fuel combustion, input energy and production process.

6. The method for calculating the carbon footprint of coal-fired power products according to claim 4, characterized in that: GWP p The GWP value in the latest climate assessment report released by IPCC is used.

7. The method for calculating the carbon footprint of coal-fired power products according to claim 1, characterized in that: In step 4, the carbon emission intensity is also calculated, and the carbon emission intensity of the coal-fired unit is calculated during the power generation phase using formula (4); （4）； In formula (4), T is the annual carbon dioxide emissions of a single coal-fired power generation unit; U c is the installed capacity of the unit; h is the annual average operating hours; γ is the load factor; ζ is the standard coal consumption; η is the carbon dioxide emission factor of standard coal.

8. The method for calculating the carbon footprint of coal-fired power products according to claim 7, characterized in that: According to the carbon emission intensity of coal-fired units, a carbon emission rating standard is formulated and a three-level system is used to rate the carbon emissions of coal-fired power generation enterprises, with carbon emission intensity <850 g (kWh) -1 As level Ⅰ, 850 g (kWh) -1 ≤Carbon emission intensity≤950 g(kWh) -1 As Level II, with carbon emission intensity > 950 g (kWh) -1 As level III.

9. The method for calculating the carbon footprint of a coal-fired power product according to any one of claims 1 to 8, characterized in that: The raw material acquisition stage includes the supply of building materials and machinery and equipment, the mining and processing of coal, and the supply of energy, water and auxiliary materials. The transportation stage includes the transportation of building materials and machinery and equipment and the transportation of coal. The operation and power generation stage includes the power plant construction stage, the operation and power generation stage and the power grid connection stage.

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