Organic fertilizer product carbon footprint accounting method

Abstract

The invention provides an organic fertilizer product carbon footprint accounting method, and belongs to the technical field of agricultural input product carbon footprint accounting. The method comprises the following steps: (1) determining a boundary and a functional unit of a carbon footprint accounting system of an organic fertilizer product; (2) collecting primary data of four stages of raw material acquisition, composting process, microbial inoculum fermentation and screening and metering according to a production process of an organic fertilizer product; (3) determining carbon emission factors in the stages of raw material acquisition, microbial inoculum fermentation and screening measurement in the step (2) and driving elements in the stage of the composting process; (4) the carbon emission factors or the driving elements are utilized to calculate the carbon emission of the four stages; and (5) solving the carbon footprint of the organic fertilizer product according to a formula 1 by utilizing the carbon emission of the four stages obtained in the step (4). The accounting method provides basic data for agricultural product carbon footprint accounting, belongs to the carbon footprint category of agricultural inputs, and fills the blank of the agricultural product carbon footprint accounting method.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon footprint accounting of agricultural inputs, and in particular relates to a method for carbon footprint accounting of organic fertilizer products. Background Art

[0002] Climate change has become a core issue of common concern to the international community. Effectively controlling global warming and reducing greenhouse gas emissions have become critical challenges that all industries must urgently address. As global climate change becomes increasingly severe, the international community has widely recognized the importance of reducing greenhouse gas (GHG) emissions and promoting green, low-carbon development. The signing of the Paris Agreement signals global resolve to address climate change, and countries are formulating and implementing nationally determined emission reduction plans with the goal of limiting the global average temperature rise to well below 2°C by the end of this century.

[0003] As essential materials for agricultural production, the carbon footprint of agricultural inputs is a crucial foundational data point for calculating the carbon footprint of agricultural products. The carbon footprint of agricultural inputs produced using different production processes varies significantly. To standardize and guide low-carbon, green production at organic fertilizer manufacturers, it is necessary to scientifically calculate the carbon emissions and carbon footprint of organic fertilizer production. This provides scientific support for manufacturers to adjust production processes and calculate the carbon footprint of agricultural products.

[0004] However, carbon footprint accounting methods for agricultural inputs, particularly those produced outside of factories, are relatively scarce, with no relevant industry or national standards. This is a crucial and crucial component of agricultural product carbon footprint accounting. This situation limits the refined management of greenhouse gas emissions in the agricultural sector and the carbon footprint or carbon labeling of agricultural products. With growing global concern about climate change, strengthening the development of standards for carbon footprint accounting for agricultural products and agricultural inputs has become an urgent need to promote green agricultural production.

[0005] There is currently no unified and referenced targeted standard regarding carbon emissions from the organic fertilizer production process or the carbon footprint of organic fertilizer products. Although the existing IPCC methodology provides some available parameters for the composting fermentation process, it is not targeted enough and does not take into account the differences in the types of production equipment and material ratios in the production stages, composting processes (such as C / N ratio, moisture content, fermentation process type, additive type), etc. Moreover, its functional unit is for a single animal and cannot be directly applied to the calculation of carbon emissions or carbon footprint per unit organic fertilizer product.

[0006] Therefore, in order to comprehensively estimate the carbon footprint of agricultural products, it is urgently necessary to scientifically estimate the carbon footprint accounting methods and key parameters of various major agricultural inputs, and provide clear and applicable methodologies and tools for agricultural product carbon footprint assessment and low-carbon production and technological improvements of agricultural input production enterprises. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a method for calculating the carbon footprint of organic fertilizer products. The present invention fully considers the differentiated conditions and specific scenarios of organic fertilizer production enterprises, provides emission parameters under different conditions, provides targeted carbon emission accounting methods for production enterprises, and provides strategic options for enterprises to try different emission reduction plans.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The present invention provides a method for calculating the carbon footprint of an organic fertilizer product, comprising the following steps: (1) Determine the carbon footprint accounting system boundary and functional unit of organic fertilizer products. The carbon footprint accounting system boundary includes four stages: raw material acquisition, composting process, microbial fermentation, and screening and measurement. The functional unit is tons of carbon dioxide equivalent / ton of organic fertilizer products; (2) Based on the production process of organic fertilizer products, collect primary data of the four stages of raw material acquisition, composting process, microbial fermentation, and screening and metering; (3) Determine the carbon emission factors of the raw material acquisition, inoculum fermentation, screening and metering stages in step (2) and the driving factors of the composting process stage; (4) Use carbon emission factors or driving factors to calculate the carbon emissions of the four stages of raw material acquisition, composting process, bacterial fermentation, and screening measurement; (5) Using the carbon emissions of the four stages obtained in step (4), the carbon footprint of the organic fertilizer product is calculated according to formula 1: ; Among them, CFP CHG is the carbon footprint of organic fertilizer products, in t CO2e / t organic fertilizer; CFP m is the carbon emission during the raw material acquisition stage, in t CO2e / t organic fertilizer; CFP c is the carbon emission during the composting process, in t CO2e / t organic fertilizer; CFP L is the carbon emission during the fermentation stage, in t CO2 / t organic fertilizer; CFP p It is the carbon emission in the screening and metering stage, and the unit is t CO2 / t organic fertilizer.

[0009] Preferably, the carbon emissions during the raw material acquisition stage are as shown in Formula 2: ; Among them, CFP m1 CFP is the carbon emissions of the raw materials used in the original production system for each ton of organic fertilizer products, measured in tCO2e / t organic fertilizer; m2is the carbon emission of raw material transportation, the unit is t CO2 / t organic fertilizer; CFP m3 It is the carbon emission from raw material pretreatment, and the unit is t CO2 / t organic fertilizer.

[0010] Preferably, the calculation formula for the carbon emissions of the raw materials used in the original production system per ton of organic fertilizer product is as shown in Formula 3: ; Among them, M i The consumption of the i-th raw material in each ton of organic fertilizer product, unit is t / t organic fertilizer; CEF i is the greenhouse gas emission factor of the i-th raw material in the original production system, in kg CO2e / kg.

[0011] Preferably, the calculation formula for the carbon emissions from the raw material transportation is as shown in Formula 4: ; Among them, FC i,j The activity data of the original consumption of the jth fuel per ton of raw material i during transportation, in L / t or m 3 / t;EF i,j-use is the carbon emission of the jth fossil fuel consumed during the transportation of raw materials during use, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 EF i,j-prod is the carbon emission of the jth fossil fuel consumed during the transportation of raw materials in the original production process, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 .

[0012] Preferably, the carbon emissions from the raw material pretreatment are calculated as shown in Formula 5: ; Where FDi is the power consumption per ton of raw material i during the pre-treatment process, in kW·h / t; EF elec is the local power grid emission factor, with the unit being t CO2 / kW·h.

[0013] Preferably, the carbon emissions of the composting process are as shown in Formula 6: ; Among them, GFP CH4 is the methane emission per ton of final product during the fermentation process, in t CH4 / t; GFP N2O N2O emissions per ton of final product during the fermentation process, in t N2O / t; GWP CH4is the global warming potential of methane on a 100-year scale, in kg CO2e / kg; GWP N2O is the global warming potential of N2O on a 100-year scale, in kg CO2e / kg; CFP CO2 It is the emission of mechanical energy consumed during the composting fermentation process, with the unit of t CO2 / t.

[0014] Preferably, the calculation formula for methane emissions per ton of final product during the fermentation process is shown in Formula 7: ; Wherein, TC is the total carbon content in each batch of fermentation mixed raw materials, and the unit is t C / batch of dry mixed materials; MeL is the percentage of CH4-C loss during fermentation to the total carbon in the initial mixed materials, and the unit is %; Pc is the dry weight fraction of the fermentation final product per ton of organic fertilizer product, and the unit is t fermentation product / t final product; i CH4 is the methane emission reduction coefficient multiplier of the additive on compost, dimensionless; PwW is the wet weight of each batch of raw materials after fermentation, unit is t (wet weight) / batch, Pw is the wet basis moisture content of each batch of materials after fermentation, unit is %; The calculation formula for the total carbon content in each batch of fermentation mixed raw materials is shown in Formula 8: ; Among them, SwW i is the wet weight of the initial raw material i in each batch of fermentation materials, unit is t / batch; C i is the dry weight organic carbon content of material i, unit is %; w i is the wet basis moisture content of raw material i, unit is %; The calculation formula for the percentage (%) of CH4-C loss in the fermentation process to the total carbon in the initial mixture is shown in Formula 9: ; Wherein, C / N is the C / N ratio of the compost mixture, dimensionless; Moist is the total moisture content of the mixture in the initial compost fermentation tank, which is the sum of the moisture contents of all raw materials plus the additional water, expressed as % of the total wet weight. The calculation formula of C / N is shown in Formula 10: ; Among them, N i is the nitrogen content per unit weight (dry weight) of the i-th raw material, in gC / kg DM; The calculation formula of Moist is shown in Formula 11: ; Among them, extraW is the additional water added to each batch of organic fertilizer products during fermentation, with the unit of t / batch, in order to ensure suitable moisture conditions for compost fermentation.

[0015] Preferably, the calculation formula for the N2O emissions per ton of final product during the fermentation process is shown in Formula 12: ; Among them, GFP N2O-direct is the direct emission, the unit is t N2O / t final product; GFP N2O-indirect is the indirect emission, the unit is t N2O / t final product; The calculation formula of the direct emissions is shown in Formula 13: ; Wherein, TN is the total nitrogen content in each batch of initial fermentation material, unit is tN / batch; NL is the percentage of N2O-N loss in each batch of fermentation material to the total nitrogen in the initial fermentation material, unit is %;i N2O is the emission reduction coefficient multiplier of the additive on compost N2O, dimensionless; Pc is the fraction of the fermentation final product of this batch per ton of final product, unit is t fermentation product / t final product; 44 and 28 are the molecular weights of N2O and nitrogen in it, respectively; The calculation formula of the total nitrogen content in each batch of fermentation material is shown in Formula 14: ; The percentage (%) of N2O-N loss in each batch of fermentation material to the total nitrogen in the initial fermentation material is calculated as shown in Formula 15: ; The calculation formula for the indirect emissions is shown in Formula 16: ; Among them, GFP NH3-N is the percentage of NH3-N loss in each batch of compost fermentation process to the total nitrogen in the initial fermentation material, in %; EF4 is the N2O-N emission coefficient of volatilized ammonia after sedimentation; i NH3 is the reduction coefficient of the additive on ammonia volatilization of compost, dimensionless; The calculation formula for the percentage (%) of NH3-N in the total nitrogen loss in the raw materials during each batch of compost fermentation is shown in Formula 17: ; The calculation formula for the emission of mechanical energy consumption during the composting fermentation process is shown in Formula 18: ; Among them, GC i，jThe activity data of the raw consumption of the jth fuel consumed by composting process equipment i to produce each ton of organic fertilizer product, in kg / t organic fertilizer or L / t organic fertilizer; GC i The power consumption of composting equipment i per ton of organic fertilizer product is expressed in kW·h / t organic fertilizer.

[0016] Preferably, the carbon emissions during the bacterial fermentation stage are as shown in Formula 19: ; Among them, AD i is the power consumption of each batch of fermentation of the i-th equipment, in kW·h / batch; Wb is the dry matter mass of bacterial powder obtained after each batch of liquid fermentation, in t / batch; P L It is the amount of dry bacteria powder added per ton of final product, with the unit being t dry bacteria powder / t final product.

[0017] Preferably, the carbon emissions in the screening and metering stage are as shown in Formula 20: ; Among them, AE i The power consumption of the i-th device per ton of final product packaged, in kW·h / t.

[0018] Compared with existing technologies, the present invention has the following advantages: It provides a method for calculating the carbon footprint of organic fertilizer products. This method fully considers the diverse conditions and specific scenarios of organic fertilizer manufacturers, providing emission parameters under different process conditions (including the C / N ratio of the fermentation material, moisture content, and additive type). This provides manufacturers with a targeted carbon emission accounting method and provides emission reduction parameters for different emission reduction processes or materials, providing strategic options for companies to explore different emission reduction strategies. This carbon footprint accounting method can directly guide organic fertilizer manufacturers in calculating greenhouse gas emissions during the composting process based on different processes, raw materials, material C / N ratios, moisture content, and other adjustment measures (acidity adjustment, additive type). This method fills a gap in carbon footprint accounting methods for agricultural inputs in the upstream production of agricultural products, providing basic data for agricultural product carbon footprint accounting. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the system boundary diagram of the organic fertilizer product life cycle, where the yellow part is the non-essential process; Figure 2 is the methane emission coefficient fitting diagram during composting (the proportion of CH4-C to the total carbon in the initial mixture, %); Figure 3 is the fitting diagram of nitrous oxide emission coefficient during composting (the ratio of N2O-N to the total nitrogen in the initial mixture, %); Figure 4 This is the fitting diagram of the ammonia emission coefficient during the composting process (the ratio of NH3-N to the total nitrogen in the initial mixture, %). DETAILED DESCRIPTION

[0020] The present invention provides a method for calculating the carbon footprint of an organic fertilizer product, comprising the following steps: (1) Determine the carbon footprint accounting system boundary and functional unit of organic fertilizer products. The carbon footprint accounting system boundary includes four stages: raw material acquisition, composting process, inoculum fermentation, and screening and metering. The functional unit is tons of carbon dioxide equivalent / ton of organic fertilizer product (abbreviated as t CO2e / t organic fertilizer); (2) Based on the production process of organic fertilizer products, collect primary data of the four stages of raw material acquisition, composting process, microbial fermentation, and screening and metering; (3) Determine the carbon emission factors of the raw material acquisition, inoculum fermentation, screening and metering stages in step (2) and the driving factors of the composting process stage; (4) Use carbon emission factors or driving factors to calculate the carbon emissions of the four stages of raw material acquisition, composting process, bacterial fermentation, and screening measurement; (5) Using the carbon emissions of the four stages obtained in step (4), the carbon footprint of the organic fertilizer product is calculated according to formula 1: ; Among them, CFP CHG is the carbon footprint of organic fertilizer products, in t CO2e / t organic fertilizer; CFP m is the carbon emission during the raw material acquisition stage, in t CO2e / t organic fertilizer; CFP c is the carbon emission during the composting process, in t CO2e / t organic fertilizer; CFP L is the carbon emission during the fermentation stage, in t CO2 / t organic fertilizer; CFP p It is the carbon emission in the screening and metering stage, and the unit is t CO2 / t organic fertilizer.

[0021] In the present invention, when the greenhouse gas emitted by a process is solely CO2, the unit is expressed as tCO2 / t of organic fertilizer. When the greenhouse gas emitted by a process is methane or nitrous oxide, the emissions are uniformly converted to CO2 equivalents (i.e., CO2e) based on the global warming potential (GWP) of CH4 or N2O, respectively. The unit of carbon emissions for this stage is tCO2e / t of organic fertilizer. After the units are uniformly converted, they can be directly added together, resulting in the unit of tCO2e / t of organic fertilizer.

[0022] In the present invention, the raw material acquisition stage starts from the production of various raw materials used in composting in the original system, and ends with their transportation to the composting site and their entry into the fermentation tank / pile through the pre-treatment process, including but not limited to the carbon emissions from the following processes: a) Carbon emissions from the storage and management of composted manure, including methane and nitrous oxide. Note that since animal manure is a byproduct of livestock and poultry farming, and the target products of livestock and poultry farming are meat, eggs, milk, and wool from farmed animals, enteric methane emissions from livestock and poultry farming are primarily accounted for within the carbon footprint of livestock products (meat, eggs, milk, wool, etc.). The carbon footprint of animal manure, as waste, only calculates carbon emissions from its storage and use. Enteric methane emissions from animal farming are no longer counted in the waste carbon footprint calculation system, avoiding multiple calculations.

[0023] b) Carbon emissions from the planting, growth and production of various straws used for composting, including methane and nitrous oxide.

[0024] c) Carbon emissions from the cultivation of raw materials used to produce inoculants added to the final bio-organic fertilizer, such as corn flour, soybean meal, and bran, including methane and nitrous oxide. This may be omitted if the amount used is less than 1% of the final product weight.

[0025] d) Carbon emissions from the original production system of additives used during composting, such as attapulgite, biochar, and phosphogypsum, are primarily carbon dioxide. These additives may be omitted if their use is less than 1% of the final product weight.

[0026] e) Carbon emissions from the production of raw materials used as additives in organic fertilizer products, such as chemical fertilizers and biochar, primarily as carbon dioxide. This may be omitted if the amount used is less than 1% of the final product weight.

[0027] f) Carbon dioxide emissions from fuel used in transportation of various raw materials to the organic fertilizer production site.

[0028] g) Greenhouse gas emissions from energy or electricity consumed during pre-treatment of compost fermentation raw materials, such as dry-wet separation, before entering the compost fermentation tank or fermentation pile.

[0029] In the present invention, the composting stage includes two stages: primary fermentation and aging. Since the aging process basically does not emit gas, only the carbon emissions of the primary fermentation process are calculated, including the methane and nitrous oxide emissions in the composting process and the carbon emissions of energy consumption of composting equipment; the carbon emissions of the liquid inoculum fermentation stage are mainly the carbon emissions of energy consumption of related equipment such as fermentation tanks; the carbon emissions of the screening and metering stage include the carbon emissions of electricity consumption of equipment in the screening, crushing, granulation, metering, packaging and other processes.

[0030] In the present invention, the distribution of the initial data of each stage in the end product and the selection of data need to be verified (raw materials with a usage of less than 1% and a total usage of less than 5% in the end product can be omitted when calculating the carbon footprint).

[0031] In the present invention, before determining the carbon footprint accounting system boundary of organic fertilizer products, it is generally necessary to collect data for more than one year. The data collection includes primary data collection and secondary data selection, wherein the primary data collection includes: (1) The purchase quantity of various raw materials (such as animal manure, straw, additives, etc.), the oil consumption of the purchase transportation vehicles during the transportation process, the energy consumption of the raw materials in the pre-treatment process (such as dry-wet separation), and the amount of each raw material in each ton of organic fertilizer final product; (2) The type and number of solid fermentation piles / tanks and liquid fermentation tanks (such as static, stack type, tank type, fermentation tank), the wet weight and moisture content of various raw materials required for the fermentation process of each fermentation type representative batch (such as each quarter) and the amount of additional water added, the wet weight and moisture content of the material discharged at the end of solid fermentation (if conditions permit, the carbon content and nitrogen content of various fermentation raw materials can be measured; if conditions do not permit, secondary data can be used), and various stirring / turning during the fermentation of representative fermentation batches (such as each quarter). The total oil consumption (e.g., diesel, liters) or electricity consumption (kWh) of the machinery such as aeration and heating during the fermentation period; if conditions permit, the emission of non-CO2 greenhouse gases (methane and nitrous oxide) during the fermentation period, including the emission parameters of methane and nitrous oxide during the fermentation process of unconventional processes or processes using self-invented patents, and the amount of compost fermentation products added to each ton of organic fertilizer final product; (3) the weight of each batch of raw materials (corn flour, soybean meal, etc.) entering the liquid fermentation tank, the dry weight at the time of discharge, the total electricity consumption (kWh) of various heating, stirring, spraying, drying and other machinery during each batch of fermentation during the fermentation period, and the amount of dry powder of microbial agent added to each ton of organic fertilizer final product; (4) the oil consumption or electricity consumption of the screening, crushing, granulating, metering, packaging and other machinery corresponding to each ton of organic fertilizer final product.

[0032] Secondary data collection includes: carbon emission coefficients of raw materials in the original production system, greenhouse gas emissions and removal factors related to energy (gas, fuel), carbon and nitrogen content of raw materials, greenhouse gas emission factors of electricity consumption, and global warming potential (GWP) of methane and nitrous oxide.

[0033] The primary data is obtained by collecting production statistics of the production enterprise in the recent financial year, and key data (such as fermentation process) can collect actual data of four representative months of the season. The secondary data is obtained by searching the public data in the database, including China National Knowledge Infrastructure (CNKI), Web of Science, current national standards and industry standards.

[0034] In the present invention, the carbon emissions during the raw material acquisition stage are shown in Formula 2: ; Among them, CFP m1 CFP is the carbon emissions of the raw materials used in the original production system for each ton of organic fertilizer products, measured in tCO2e / t organic fertilizer; m2 is the carbon emission of raw material transportation, the unit is t CO2 / t organic fertilizer; CFP m3 It is the carbon emission from raw material pretreatment, and the unit is t CO2 / t organic fertilizer.

[0035] In the present invention, the calculation formula for the carbon emissions of the raw materials used in the original production system per ton of organic fertilizer product is shown in Formula 3: ; Among them, M i The consumption of the i-th raw material in each ton of organic fertilizer product, unit is t / t organic fertilizer; CEF i is the greenhouse gas emission factor of the i-th raw material in the original production system, in kg CO2e / kg.

[0036] In the present invention, the greenhouse gas emission factors of raw material production are obtained by obtaining secondary data (emission factors).

[0037] In the present invention, the calculation formula for the carbon emissions from raw material transportation is shown in Formula 4: ; Among them, FC i,j The activity data of the original consumption of the jth fuel per ton of raw material i during transportation, in L / t or m 3 / t;EF i,j-use. is the carbon emission of the jth fossil fuel consumed during the transportation of raw materials during use, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 EF i,j-prod is the carbon emission of the jth fossil fuel consumed during the transportation of raw materials in the original production process, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 .

[0038] In the present invention, the calculation formula for the carbon emissions from the raw material pretreatment is shown in Formula 5: ; Where FDi is the power consumption per ton of raw material i during the pre-treatment process, in kW·h / t; EF elecis the local power grid emission factor, with the unit being t CO2 / kW·h.

[0039] In the present invention, the local grid electricity emission factor is obtained through secondary data.

[0040] In the present invention, the carbon emissions of the composting process are shown in Formula 6: ; Among them, GFP CH4 is the methane emission per ton of final product during the fermentation process, in t CH4 / t; GFP N2O N2O emissions per ton of final product during the fermentation process, in t N2O / t; GWP CH4 is the global warming potential of methane on a 100-year scale, in kg CO2e / kg; GWP N2O is the global warming potential of N2O on a 100-year scale, in kg CO2e / kg; CFP CO2 It is the emission of mechanical energy consumed during the composting fermentation process, with the unit of t CO2 / t.

[0041] In the present invention, the global warming potential of methane on a 100-year scale and the global warming potential of N2O on a 100-year scale are both obtained through secondary data.

[0042] In the present invention, the calculation formula for the methane emissions per ton of final product during the fermentation process is shown in formula (7): ; Wherein, TC is the total carbon content in each batch of fermentation mixed raw materials, and the unit is t C / batch of dry mixed materials; MeL is the percentage of CH4-C loss during fermentation to the total carbon in the initial mixed materials, and the unit is %; Pc is the dry weight fraction of the fermentation final product per ton of organic fertilizer product, and the unit is t fermentation product / t final product; i CH4 is the methane emission reduction coefficient multiplier of the additive on compost, dimensionless; PwW is the wet weight of each batch of raw materials after fermentation, unit is t (wet weight) / batch, Pw is the wet basis moisture content of each batch of materials after fermentation, unit is %; The calculation formula for the total carbon content in each batch of fermentation mixed raw materials is shown in Formula 8: ; Among them, SwW i is the wet weight of the initial raw material i in each batch of fermentation materials, unit is t / batch; C i is the dry weight organic carbon content of material i, unit is %; w i is the wet basis moisture content of raw material i, unit is %; The calculation formula for the percentage (%) of CH4-C loss in the fermentation process to the total carbon in the initial mixture is shown in Formula 9: ; Wherein, C / N is the C / N ratio of the compost mixture, dimensionless; Moist is the total moisture content of the mixture in the initial compost fermentation tank, which is the sum of the moisture contents of all raw materials plus the additional water, expressed as % of the total wet weight. The calculation formula of C / N is shown in Formula 10: ; Among them, N i is the nitrogen content per unit weight (dry weight) of the i-th raw material, in gC / kg DM; The calculation formula of Moist is shown in Formula 11: ; Among them, extraW is the additional water added to each batch of organic fertilizer products during fermentation, with the unit of t / batch, in order to ensure suitable moisture conditions for compost fermentation.

[0043] In the present invention, the percentage of CH4-C loss during fermentation to the total carbon in the initial mixture, MeL, is obtained by summarizing and fitting the data extracted from the literature, and the value range is between 0.01% and 1%. CH4 It is dimensionless and is obtained from secondary data between 0 and 1. The moisture content of each batch of materials after fermentation, Pw (%), is obtained through primary data collection. The organic carbon content C of material i i Obtained through primary data or secondary data. The moisture content w of material i i Moisture content is measured on a wet basis, obtained through primary measurements or secondary data. The initial moisture content of the compost mix ranges from 50% to 70%, and is a key primary data point that companies need to collect.

[0044] In the present invention, the calculation formula for the N2O emissions per ton of final product during the fermentation process is shown in Formula 12: ; Among them, GFP N2O-direct is the direct emission, the unit is t N2O / t final product; GFP N2O-indirect is the indirect emission, the unit is t N2O / t final product; The calculation formula of the direct emissions is shown in Formula 13: ; Wherein, TN is the total nitrogen content in each batch of initial fermentation material, unit is tN / batch; NL is the percentage of N2O-N loss in each batch of fermentation material to the total nitrogen in the initial fermentation material, unit is %;i N2O is the emission reduction coefficient multiplier of the additive on compost N2O, dimensionless; Pc is the fraction of the fermentation final product of this batch per ton of final product, unit is t fermentation product / t final product; 44 and 28 are the molecular weights of N2O and nitrogen in it, respectively; The calculation formula for the total nitrogen content in each batch of initial fermentation material is shown in Formula 14: ; The percentage NL (%) of N2O-N loss in each batch of fermentation material to the total nitrogen in the initial fermentation material is calculated as shown in Formula 15: ; The calculation formula for the indirect emissions is shown in Formula 16: ; Among them, GFP NH3-N is the percentage of NH3-N loss in each batch of compost fermentation process to the total nitrogen in the initial fermentation material, in %; EF4 is the N2O-N emission coefficient of volatilized ammonia after sedimentation; i NH3 is the reduction coefficient of the additive on ammonia volatilization of compost, dimensionless; The calculation formula for the percentage of NH3-N loss in the compost fermentation process to the total nitrogen in the initial fermentation material is shown in Formula 17: .

[0045] In the present invention, the direct emission GFP N2O-direct The reduction coefficient i of the additive on N2O in compost is obtained after summarizing the data. N2O It is dimensionless (between 0 and 1) and is obtained from secondary data. The percentage of NH3-N lost in the total nitrogen in the raw materials during each batch of compost fermentation is GFP. NH3-N The N2O-N emission coefficient EF4 of volatilized ammonia after settling is obtained by summarizing and fitting data collected from the literature. The value in the 2006 IPCC Greenhouse Gas Inventory Guidelines is 0.01 kgN2O-N / kgNH3-N. The reduction coefficient i of the ammonia volatilization of compost by the additive is NH3 It is dimensionless (between 0 and 1) and is obtained from secondary data.

[0046] In the present invention, the calculation formula for the emission of mechanical energy consumption during the composting fermentation process is shown in Formula 18: ; Among them, GC i，jThe raw consumption activity data of the jth fuel consumed by equipment i in the composting process to produce each ton of organic fertilizer product (referring to the emissions of energy consumed by stirring equipment, compost turning equipment or fermentation tanks during the fermentation process), in kg / t organic fertilizer or L / t organic fertilizer; GC i The power consumption of composting equipment i per ton of organic fertilizer product is expressed in kW·h / t organic fertilizer.

[0047] In the present invention, the carbon emissions during the bacterial fermentation stage are shown in Formula 19: ; Among them, AD i is the power consumption of each batch of fermentation of the i-th equipment, in kW·h / batch; Wb is the dry matter mass of bacterial powder obtained after each batch of liquid fermentation, in t / batch; P L It is the amount of dry bacteria powder added per ton of final product, with the unit being t dry bacteria powder / t final product.

[0048] In the present invention, the power consumption of the equipment during each batch of fermentation and the mass of the bacterial powder dry matter obtainable after each batch of liquid fermentation are obtained through primary data.

[0049] In the present invention, the carbon emissions in the screening and metering stage are shown in Formula 20: ; Among them, AE i The power consumption of the i-th device per ton of final product packaged, in kW·h / t.

[0050] In the present invention, the daily power consumption of the i-th device is obtained through primary data.

[0051] In the present invention, the selection of the material (energy) data involved follows the following criteria: a) All energy inputs and production emissions must be listed; b) The main raw materials should be listed, and the contribution of any negligible single material (energy) flow or unit process to the product carbon footprint should not exceed 1%; c) The total contribution of all ignored material (energy) flows and unit processes to the product carbon footprint does not exceed 5%, and this should be stated in the carbon footprint report; d) The consumption and emissions of infrastructure facilities such as factory buildings, warehouses, computers for managing ledgers, and personnel and living facilities within the factory are all ignored.

[0052] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0053] Example 1 Data Collection and Quality Control 1.1 Data collection at each stage according to Figure 1 The carbon footprint accounting system of organic fertilizer products is divided into four stages: raw material acquisition, composting process, bacterial fermentation, and screening and metering. Data for each stage are collected according to Table 1.

[0054] Table 1 List of data to be collected Among them, field data is primary data, which is the data that production enterprises need to collect on site; secondary data refers to public data that can be referenced in the database.

[0055] 1.2 Data Collection Methods and Quality Control The primary data of the raw material acquisition unit needs to collect the following data: the purchase quantity of various raw materials (such as animal manure, straw, additives, etc.); the fuel consumption or distance of the purchase transportation vehicle during the transportation process; the type and amount of energy consumed in the raw material processing process; the amount of various raw materials in each ton of organic fertilizer.

[0056] Data to be collected for primary data of production units: a) Solid composting fermentation unit: type and quantity of solid fermentation piles / tanks and liquid fermentation tanks (e.g. static, windrow, tank, fermentation tank); wet weight and moisture content of various raw material inputs required for the fermentation process of a representative batch of each fermentation type (e.g. animal manure, straw fermentation bacteria, other additives); wet weight and moisture content of the discharged material at the end of solid fermentation; amount of fermentation final product per ton of organic fertilizer product. If conditions permit, the total carbon and total nitrogen content of various fermentation raw materials can be measured; if conditions do not permit, secondary data can be used. Fuel consumption or electricity consumption of various stirring / turning / aeration machines during the fermentation of a representative fermentation batch; b) If conditions permit, measure non-CO2 greenhouse gas (methane and nitrous oxide) emissions during fermentation. For fermentation processes using unconventional processes or proprietary inventions, it is recommended to conduct targeted parameter measurements of methane and nitrous oxide emissions. c) Liquid fermentation unit: the weight of each batch of raw materials (corn flour, soybean meal, etc.) entering the liquid fermentation tank, the dry weight of the materials at discharge, the total power consumption of various heating, stirring, spraying, drying and other machines during each batch of fermentation, and the amount of dry powder of microbial agent added per ton of organic fertilizer product; d) Primary data of the screening and metering stage: the fuel consumption or electricity consumption (kWh) of the screening, metering and packaging machinery for each ton of organic fertilizer produced; the fuel consumption or electricity consumption of the granulation equipment (mixing, spraying, drying) and metering and packaging equipment for each ton of granulated particles produced during the entire granulation, screening and packaging stage.

[0057] Secondary data collection: data collection ended at the end of 2023. Enter keywords such as "composting" and "greenhouse gas emissions" in the China National Knowledge Infrastructure (CNKI) and Web of Science to obtain relevant literature: carbon emissions of raw materials in the original production system, Table 2; greenhouse gas emission factors related to energy (water, electricity, gas, fuel) Table 3; carbon and nitrogen content of raw materials, Tables 4 and 5.

[0058] Table 2 Reference values ​​of carbon emissions of main raw materials in the original production system (kg CO2e / kg raw material dry matter) Table 3 Common fossil energy emission factors Table 4 Nutrient content of common livestock and poultry manure

[0059] Table 5 Nutrient content of common straw

[0060] Example 2 Carbon emissions from raw material acquisition process Carbon emissions from the raw material acquisition process include the carbon emissions per ton of organic fertilizer produced from the raw materials in the original production system, the carbon emissions from raw material transportation, and the carbon emissions from raw material processing. This paper only considers the carbon emissions parameters of the main raw materials used in the fermentation production process (carbon emissions per ton of organic fertilizer produced from the raw materials in the original production system: compost raw materials mainly include livestock manure and plant straw. The carbon emissions of plant straw in the original production system are summarized based on data from CNKI, Web of Science, and publicly published books and standards, and the results are shown in Table 2). Therefore, the carbon emissions from the raw material acquisition stage are shown in Equation 2: ; Among them, CFP m1 CFP is the carbon emissions of the raw materials used in the original production system for each ton of organic fertilizer products, measured in tCO2e / t organic fertilizer; m2 is the carbon emission of raw material transportation, the unit is t CO2 / t organic fertilizer; CFP m3 It is the carbon emission from raw material processing, and the unit is t CO2 / t organic fertilizer.

[0061] The calculation formula for the carbon emissions of the raw materials used in the original production system per ton of organic fertilizer products is shown in Formula 3: ; Among them, M i The consumption of the i-th raw material in each ton of organic fertilizer product, unit is t / t organic fertilizer; CEFi is the greenhouse gas emission factor of the i-th raw material or energy in the original production system (see Table 2), in kg CO2e / kg.

[0062] The calculation formula for carbon emissions from raw material transportation is shown in Formula 4: ; Among them, FC i,j The activity data of the original consumption of the jth fuel per ton of raw material i during transportation, in L / t or m 3 / t;EF i,j-ues is the carbon emission of the jth fossil fuel consumed during the transportation of raw materials during use, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 , see Table 3 for details; EF i,j-prod is the carbon emission of the jth fossil fuel consumed during the transportation of raw materials in the original production process, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 , see Table 3 for details.

[0063] The calculation formula for carbon emissions from raw material processing is shown in Equation 5: ; Where FDi is the power consumption per ton of raw material i during the pre-treatment process, in kW·h / t; EF elec is the local power grid emission factor (see Table 6), with the unit being t CO2 / kW·h.

[0064] Table 6 Electricity emission factors of various power grids in 2022 (kg CO2 / kW·h)

[0065] Example 3 Carbon emissions during the composting process Greenhouse gas emissions from composting are calculated using Equation 6. ; Among them, GFP CH4 The methane emission per ton of fermentation final product during the fermentation process, unit is t CH4 / t; GFP N2O N2O emissions per ton of fermentation product during the fermentation process, in t N2O / t; GWP CH4 is the global warming potential of methane on a 100-year scale (see Table 7), in kg CO2e / kg; GWP N2O is the global warming potential of N2O on a 100-year scale (see Table 7), in kg CO2e / kg; CFPCO2 It is the emission of mechanical energy consumed during the composting fermentation process, with the unit of t CO2 / t.

[0066] Table 7 Global Warming Potential (GWP)

[0067] 3.1 Methane emissions from composting During the composting fermentation production process, due to local hypoxia and alternating anaerobic and aerobic conditions in some areas during the decomposition of carbon- and nitrogen-containing organic materials, greenhouse gases methane and nitrous oxide will be emitted. Carbon dioxide emissions are not currently included (because biogenic carbon dioxide originally comes from atmospheric carbon dioxide and returns to the atmosphere, it is not considered "anthropogenic emissions" and is therefore not included in the current system).

[0068] Methane emissions during the composting process are primarily the product of anaerobic decomposition of organic carbon sources (while aerobic decomposition produces carbon dioxide). Nitrogenous compounds in organic materials produce nitrous oxide (NTO) during mineralization and nitrification-denitrification, two major greenhouse gases in the composting process. Furthermore, ammonium nitrogen produced during the decomposition of nitrogen-containing organic matter is converted to ammonia (NH3) under alkaline conditions and volatilized into the environment. This ammonia also undergoes nitrogen deposition within a small area back into the composting system, where it indirectly produces NTO through nitrification and denitrification. Therefore, greenhouse gas emissions during the composting process primarily account for these three components to fully assess the carbon emission equivalent of the process. Therefore, the formula for calculating methane emissions during the fermentation process per ton of fermentation final product is shown in Equation 7: ; Wherein, TC is the total carbon content in each batch of fermentation mixed raw materials, and the unit is t C / batch of dry mixed materials; MeL is the percentage of CH4-C loss during fermentation to the total carbon in the initial mixed materials, and the unit is %; Pc is the dry weight fraction of the fermentation final product per ton of organic fertilizer product, and the unit is t fermentation product / t final product; i CH4 is the methane emission reduction coefficient multiplier of the additive on compost, dimensionless, between 0 and 1, derived according to DB3308 / T143-2023, see Table 8 for details; PwW is the wet weight of each batch of raw materials after fermentation, the unit is t (wet weight) / batch, Pw is the wet basis moisture content of each batch of materials after fermentation, the unit is %.

[0069] The calculation formula for the total carbon content in each batch of fermentation mixed raw materials is shown in Formula 8: ; Among them, SwW i is the wet weight of the initial raw material i in each batch of fermentation materials, unit is t / batch; C iis the dry weight organic carbon content of material i, unit is %; w i is the moisture content of raw material i on a wet basis, in %.

[0070] According to the "Technical Specifications for Composting of Livestock and Poultry Manure NY / T 3442-2019" issued by the Ministry of Agriculture and Rural Affairs, the C / N ratio of the materials in the compost should be between 20:1 and 40:1, the moisture content of the mixture should be between 55% and 65%, and the pH should be between 5.5 and 9.0.

[0071] Cumulative gas emissions during composting are primarily related to the compost mixture's C / N ratio (Wang et al., 2017), moisture content (Li Danyang et al., 2020), aeration (turning frequency, active aeration intensity or frequency) (Zhang et al., 2020; Qu Jiulan et al., 2021), and pH (Liu et al., 2023). Furthermore, the use of composting additives, including physical (such as biochar, phosphogypsum, and lignite), chemical (acids), and biological (microbial agents), can significantly reduce various odors and greenhouse gas emissions during composting (Luo et al., 2013; Jiang et al., 2014; Wang et al., 2014; Liu et al., 2020), and minimize nutrient losses. Composting is divided into primary and secondary fermentation stages. Primary fermentation is the rapid decomposition of organic matter into small-molecule carbon and nitrogen compounds and gases, typically taking 15-20 days. Secondary fermentation is primarily a post-ripening process, where small-molecule compounds polymerize and cross-link to form high-molecular-weight humus. Gas emissions are primarily concentrated in the primary fermentation stage. Composting times for chop and tank processes vary slightly in different seasons (e.g., winter and summer). Reactor processes are less affected by ambient temperature, resulting in minimal seasonal variations. While instantaneous gas emission fluxes vary with fermentation duration, the criteria for fermentation termination are generally consistent: complete degradation of organic matter, reduction of moisture content to 40%-45%, and reduction of material temperature to ambient temperature (≤35°C). Cumulative emissions during the decomposition period are similar. Gas emissions during composting primarily occur during the high-temperature decomposition of organic matter, particularly ammonia and N2O (Jiang et al., 2011). Emission peaks vary across different process modes, but after the primary fermentation, they are generally decomposed into small molecules.

[0072] Because the C / N ratio, initial moisture content, and material pH vary across different processes and material decomposition, it's necessary to perform targeted calculations of various gas emissions during the composting process based on these specific process parameters. This study collected literature available up to the end of 2023, entering keywords such as "composting" and "greenhouse gas emissions" into the China National Knowledge Infrastructure (CNKI) and Web of Science to obtain measured data from 87 publicly available publications. This study used a regression equation to estimate the relationship between the main influencing factors and carbon and nitrogen greenhouse gas emissions during the composting process (excluding outliers that exceeded the database mean by three standard deviations).

[0073] From the measured database established from the collected literature, the values ​​of additives and some extreme values ​​(outside the 95% confidence interval) were eliminated. By establishing quantitative relationships with the main factors, the relationship between the C / N ratio and the initial moisture content of the compost mixture (hereinafter referred to as "Moist") and the percentage (%) of CH4-C loss in the compost material to the total carbon in the initial fermentation material (i.e., CH4-C emission fraction), and the percentage of N2O-N and NH3-N loss to the total nitrogen in the initial fermentation material (i.e., N2O-N emission fraction and NH3-N emission fraction) was obtained. The details are as follows: The CH4 emission fraction is the percentage (%) of carbon lost as methane gas during composting to the total carbon in the initial material. It is analyzed and fitted based on the data collected and screened from the literature ( Figure 2 ), the calculation formula for the methane carbon emission fraction during the fermentation process is shown in Equation 9 ; Wherein, C / N is the C / N ratio of the compost mixture, dimensionless; Moist is the total moisture content of the mixture in the initial compost fermentation tank, which is the additional moisture added to the sum of the moisture contents of all raw materials, expressed as % of the total wet weight. The calculation formula for C / N is shown in Equation 10: ; Among them, N i is the nitrogen content per unit weight (dry weight) of the i-th raw material, in gC / kg DM; The calculation formula of Moist is shown in Formula 11: ; Among them, extraW is the additional water added to the fermentation tank for each batch of organic fertilizer products, with the unit of t / batch, in order to ensure suitable moisture conditions for compost fermentation.

[0074] Table 8 Emission reduction coefficient multipliers of main gases in composting process by additives (dimensionless)

[0075] 3.2 Direct Nitrous Oxide Emissions from Composting Nitrous oxide emissions from the composting process are divided into direct emissions and indirect emissions (see Equation 12, , among which GFP N2O-direct is the direct emission, the unit is t N2O / t final product; GFP N2O-indirect is the indirect emission, the unit is t N2O / t final product), among which the direct emission of nitrous oxide is analyzed and fitted based on the data collected and screened from the literature ( Figure 3 ), the calculation formula for direct nitrous oxide emissions is shown in Equation 13 ; Among them, TN is the total nitrogen content in each batch of fermentation material, the unit is tN / batch, NL is the percentage of N2O-N loss in each batch of fermentation material to the total nitrogen in the initial fermentation material, the unit is %;i N2O is the N2O emission reduction coefficient multiplier of the additive on composting (dimensionless, between 0 and 1, derived according to DB3308 / T143-2023, see Table 8, and is 1 when no additive is used in the composting process); Pc is the fraction of the fermentation final product of this batch per ton of final product, with the unit being tons of fermentation product / ton of final product; 44 and 28 are the molecular weights of N2O and the nitrogen in it, respectively; The calculation formula for the total nitrogen content in each batch of fermentation material is shown in Formula 14: ; NL is the N2O-N emission fraction NL in each batch of fermentation material, which refers to the percentage (%) of N2O-N loss during the fermentation process to the total nitrogen in the initial fermentation material. Its calculation formula is shown in Equation 15: .

[0076] 3.3 Indirect Nitrous Oxide Emissions from Composting Indirect nitrous oxide emissions are N2O emissions from nitrogen lost in composting through ammonia volatilization and then deposited in the form of nitrogen deposition. Specific calculations can be made using Equation 16. ; Among them, GFP NH3-N is the NH3-N loss fraction, which refers to the percentage of NH3-N loss during the fermentation process to the total nitrogen in the initial fermentation material (%); EF4 is the N2O-N emission coefficient of volatilized ammonia after sedimentation, referring to the value in the "2006 IPCC Greenhouse Gas Inventory Guidelines", that is, 0.01 kgN2O-N / kgNH3-N; i NH3is the reduction coefficient of ammonia volatilization from composting caused by additives (dimensionless, between 0 and 1, see Table 8, derived according to DB3308 / T143-2023, and taken as 1 when no additives are used in the composting process); The NH3-N loss fraction during composting fermentation was analyzed and fitted based on the data collected from the literature. Figure 4 , the calculation formula is shown in formula 17: .

[0077] 3.4 Emissions from mechanical energy consumption during composting The calculation formula for the emission of mechanical energy consumption during composting fermentation is shown in Equation 18: ; Among them, GC i，j The activity data of the raw consumption of the jth fuel by equipment i in the composting process for producing one ton of organic fertilizer, in kg / t organic fertilizer or L / t organic fertilizer; EF i，j-use is the carbon emission during the use of the jth fossil fuel consumed by the i-th equipment in the composting process, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 , see Table 6 for details; EF i，j-prod is the carbon emission of the jth fossil fuel consumed in the original production process of the i-th raw material in the composting process, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 , see Table 3 for details; EF elec is the local power grid emission factor (see Table 6), unit is t CO2 / kW·h; GC i The power consumption of composting equipment i per ton of organic fertilizer product is expressed in kW·h / t organic fertilizer.

[0078] Example 4 Carbon emissions during the fermentation stage The carbon emissions of the bacterial powder added to the biological organic fertilizer product during the fermentation production process include emissions from the raw material production and transportation process and carbon emissions from the bacterial strain during the fermentation process. Among them, the fermentation raw materials generally include corn flour, soybean meal, bran, glucose, ammonium sulfate, potassium dihydrogen phosphate, calcium carbonate, original bacteria, etc., which can be calculated with reference to Formula 3. Since the proportion of this part of raw materials in the total raw materials (mainly animal manure) is far less than 5%, it is omitted in the present invention. The bacterial strain production fermentation process is liquid fermentation in a fermentation tank, including sterilization, fermentation growth, spray drying and other steps. The emissions are mainly carbon emissions from equipment electricity consumption. The equipment involved includes steam generators, air compressors, liquid fermentation tanks, spray dryers, etc., and each production enterprise has slightly different equipment conditions; and it needs to be calculated based on the amount of bacterial powder added per ton of organic fertilizer product. Carbon emissions from liquid fermentation process (CFP L ) is calculated according to formula 19, ; Among them, AD i EF is the power consumption of each batch of fermentation of the i-th equipment, in kW·h / batch; elec is the local power grid emission factor (see Table 6), that is, the carbon emission per 1kW·h of electricity consumed, in units of t CO2 / kW·h; Wb is the dry matter mass of bacterial powder obtained at the end of each batch of liquid fermentation, in units of t / batch; P L It is the amount of dry bacteria powder added per ton of final product, with the unit being t dry powder / t final product.

[0079] Example 5 Carbon emissions during screening and metering The carbon emissions from the screening and metering process are mainly from the electricity consumption of equipment in the screening, crushing, granulation, metering, and packaging processes. The specific calculation formula is shown in Equation 20. ; Among them, AE i EF is the power consumption of the i-th device per ton of final product packaged, in kW·h / t; elec is the local power grid emission factor (see Table 6), with the unit being t CO2 / kW·h.

[0080] Experimental example The method of the present invention was used to calculate the carbon footprint of the bio-organic fertilizer "Zhongjin No. 1" produced by Jinan Jinniu Fertilizer Co., Ltd. The company used horizontal reactors in the composting process when producing the bio-organic fertilizer "Zhongjin No. 1." Each reactor used 8 tons of cow dung (wet weight), and after fermentation, 1.8 tons of organic fertilizer product (dry weight) was obtained. Table 9 shows the relevant primary data of the bio-organic fertilizer "Zhongjin No. 1" produced by Jinan Jinniu Fertilizer Co., Ltd.

[0081] Table 9 Primary data table of carbon footprint quantification of cow dung organic fertilizer products

[0082] Raw material acquisition stage (Formula 2): ; Composting fermentation stage: The C / N ratio of the compost mixture is (Equation 10): ; The total moisture content (%) of the mixture in the compost fermentation tank is (Equation 11): ; The percentage (%) of CH4-C loss during fermentation to the total carbon in the initial mixture (Equation 9): =12.6009+0.0344×17.7732-0.4665×60+0.0002×17.7732 2 +0.0043×60 2 -0.0007×60×17.7732 =0.0190(%); The total carbon content in each batch of fermentation mixed raw materials (dry weight) is (Equation 8): ; The total nitrogen content in each batch of fermentation material is (Formula 14): ; The percentage NL of N2O-N loss in each batch of fermentation material to the total nitrogen in the initial fermentation material is (Equation 15): ; The methane emissions per ton of final product during the fermentation process are (Equation 7): ; The direct N2O emissions per ton of final product during the fermentation process are (Equation 13): ; The percentage of NH3-N lost in the total nitrogen in the raw materials during each batch of composting fermentation is (Equation 17): ; The indirect N2O emissions per ton of final product during the fermentation process are (Equation 16): ; The N2O emissions per ton of final product during the fermentation process are (Equation 12): ; Emissions of mechanical energy consumption during composting (Equation 18): ; The carbon emissions during the composting process are (Equation 6): ; The carbon emission during the liquid fermentation stage is (Equation 19): ; Screening and metering stage (Equation 20): ; The carbon footprint of the bio-organic fertilizer product is (Formula 1): .

[0083] From this, we can see that the carbon footprint of the bio-organic fertilizer "Zhongjin No. 1" produced by Jinan Jinniu Fertilizer Co., Ltd. is 0.3334t CO2e / t organic fertilizer.

[0084] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for calculating the carbon footprint of an organic fertilizer product, characterized in that: The following steps are involved: (1) Determine the carbon footprint accounting system boundary and functional unit of organic fertilizer products. The carbon footprint accounting system boundary includes four stages: raw material acquisition, composting process, microbial fermentation, and screening and measurement. The functional unit is tons of carbon dioxide equivalent / ton of organic fertilizer products; (2) Based on the production process of organic fertilizer products, collect primary data of the four stages of raw material acquisition, composting process, microbial fermentation, and screening and metering; (3) Determine the carbon emission factors of the raw material acquisition, inoculum fermentation, screening and metering stages in step (2) and the driving factors of the composting process stage; (4) Use carbon emission factors or driving factors to calculate the carbon emissions of the four stages of raw material acquisition, composting process, bacterial fermentation, and screening measurement; (5) Using the carbon emissions of the four stages obtained in step (4), the carbon footprint of the organic fertilizer product is calculated according to formula 1: ； Among them, CFP CHG is the carbon footprint of organic fertilizer products, in t CO2e / t organic fertilizer; CFP m is the carbon emission during the raw material acquisition stage, in t CO2e / t organic fertilizer; CFP c is the carbon emission during the composting process, in t CO2e / t organic fertilizer; CFP L is the carbon emission during the fermentation stage, in t CO2 / t organic fertilizer; CFP p It is the carbon emission in the screening and metering stage, and the unit is t CO2 / t organic fertilizer.

2. The method for calculating the carbon footprint of an organic fertilizer product according to claim 1, wherein: The carbon emissions during the raw material acquisition phase are shown in Formula 2: ； Among them, CFP m1 CFP is the carbon emission of raw materials used in the original production system for each ton of organic fertilizer product, in t CO2e / t organic fertilizer; m2 is the carbon emission of raw material transportation, the unit is t CO2 / t organic fertilizer; CFP m3 It is the carbon emission from raw material pretreatment, and the unit is t CO2 / t organic fertilizer.

3. The method for calculating the carbon footprint of an organic fertilizer product according to claim 2, wherein: The calculation formula for the carbon emissions of the raw materials used in the original production system per ton of organic fertilizer products is shown in Formula 3: ； Among them, M i The consumption of the i-th raw material in each ton of organic fertilizer product, unit is t / t organic fertilizer; CEF i is the greenhouse gas emission factor of the i-th raw material in the original production system, in kg CO2e / kg.

4. The method for calculating the carbon footprint of an organic fertilizer product according to claim 2, wherein: The calculation formula for the carbon emissions from raw material transportation is shown in Formula 4: ； Among them, FC i,j The activity data of the original consumption of the jth fuel per ton of raw material i during transportation, in L / t or m 3 / t;EF i,j-use is the carbon emission of the jth fossil fuel consumed during the transportation of raw materials during use, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 EF i,j-prod is the carbon emission of the jth fossil fuel consumed during the transportation of raw materials in the original production process, in kg CO2 / kg, kg CO2 / L or kg CO2 / Nm 3 .

5. The method for calculating the carbon footprint of an organic fertilizer product according to claim 2, wherein: The calculation formula for the carbon emissions from the raw material pretreatment is shown in Formula 5: ； Where FDi is the power consumption per ton of raw material i during the pre-treatment process, in kW·h / t; EF elec is the local power grid emission factor, with the unit being t CO2 / kW·h.

6. The method for calculating the carbon footprint of an organic fertilizer product according to claim 1, wherein: The carbon emissions of the composting process are shown in Equation 6: ； Among them, GFP CH4 is the methane emission per ton of final product during the fermentation process, in t CH4 / t; GFP N2O N2O emissions per ton of final product during the fermentation process, in t N2O / t; GWP CH4 is the global warming potential of methane on a 100-year scale, in kg CO2e / kg; GWP N2O is the global warming potential of N2O on a 100-year scale, in kg CO2e / kg; CFP CO2 It is the emission of mechanical energy consumed during the composting fermentation process, with the unit of t CO2 / t.

7. The method for calculating the carbon footprint of an organic fertilizer product according to claim 6, wherein: The calculation formula for the methane emissions per ton of final product during the fermentation process is shown in Formula 7: ； Wherein, TC is the total carbon content in each batch of fermentation mixed raw materials, and the unit is t C / batch of dry mixed materials; MeL is the percentage of CH4-C loss during fermentation to the total carbon in the initial mixed materials, and the unit is %; Pc is the dry weight fraction of the fermentation final product per ton of organic fertilizer product, and the unit is t fermentation product / t final product; i CH4 is the methane emission reduction coefficient multiplier of the additive on compost, dimensionless; PwW is the wet weight of each batch of raw materials after fermentation, unit is t (wet weight) / batch, Pw is the wet basis moisture content of each batch of materials after fermentation, unit is %; The calculation formula for the total carbon content in each batch of fermentation mixed raw materials is shown in Formula 8: ； Among them, SwW i is the wet weight of the initial raw material i in each batch of fermentation materials, unit is t / batch; C i is the dry weight organic carbon content of material i, unit is %; w i is the wet basis moisture content of raw material i, unit is %; The calculation formula for the percentage (%) of CH4-C loss in the fermentation process to the total carbon in the initial mixture is shown in Formula 9: ； Wherein, C / N is the C / N ratio of the compost mixture, dimensionless; Moist is the total moisture content of the mixture in the initial compost fermentation tank, which is the sum of the moisture contents of all raw materials plus the additional water, expressed as % of the total wet weight. The calculation formula of C / N is shown in Formula 10: ； Among them, N i is the nitrogen content per unit weight (dry weight) of the i-th raw material, in gC / kg DM; The calculation formula of Moist is shown in Formula 11: ； Among them, extraW is the additional water added to each batch of organic fertilizer products during fermentation, with the unit of t / batch, in order to ensure suitable moisture conditions for compost fermentation.

8. The method for calculating the carbon footprint of an organic fertilizer product according to claim 6, wherein: The calculation formula for the N2O emissions per ton of final product during the fermentation process is shown in Formula 12: ； Among them, GFP N2O-direct is the direct emission, the unit is t N2O / t final product; GFP N2O-indirect is the indirect emission, the unit is t N2O / t final product; The calculation formula of the direct emissions is shown in Formula 13: ； Wherein, TN is the total nitrogen content in each batch of initial fermentation material, unit is tN / batch; NL is the percentage of N2O-N loss in each batch of fermentation material to the total nitrogen in the initial fermentation material, unit is %;i N2O is the emission reduction coefficient multiplier of the additive on compost N2O, dimensionless; Pc is the fraction of the fermentation final product of this batch per ton of final product, unit is t fermentation product / t final product; 44 and 28 are the molecular weights of N2O and nitrogen in it, respectively; The calculation formula of the total nitrogen content in each batch of fermentation material is shown in Formula 14: ； The percentage NL (%) of N2O-N loss in each batch of fermentation material to the total nitrogen in the initial fermentation material is calculated as shown in Formula 15: ； The calculation formula for the indirect emissions is shown in Formula 16: ； Among them, GFP NH3-N is the percentage of NH3-N lost in the total nitrogen in the raw materials during each batch of composting fermentation, in %; EF4 is the N2O-N emission coefficient of volatilized ammonia after sedimentation; i NH3 is the reduction coefficient of the additive on ammonia volatilization of compost, dimensionless; The calculation formula for the percentage (%) of NH3-N in the total nitrogen loss in the raw materials during each batch of compost fermentation is shown in Formula 17: ； The calculation formula for the emission of mechanical energy consumption during the composting fermentation process is shown in Formula 18: ； Among them, GC i，j The activity data of the raw consumption of the jth fuel consumed by composting process equipment i to produce each ton of organic fertilizer product, in kg / t organic fertilizer or L / t organic fertilizer; GC i The power consumption of composting equipment i per ton of organic fertilizer product is expressed in kW·h / t organic fertilizer.

9. The method for calculating the carbon footprint of an organic fertilizer product according to claim 1, wherein: The carbon emissions during the fermentation stage are shown in Formula 19: ； Among them, AD i is the power consumption of each batch of fermentation of the i-th equipment, in kW·h / batch; Wb is the dry matter mass of bacterial powder obtained after each batch of liquid fermentation, in t / batch; P L It is the amount of dry bacteria powder added per ton of final product, with the unit being t dry bacteria powder / t final product.

10. The method for calculating the carbon footprint of an organic fertilizer product according to claim 1, wherein: The carbon emissions during the screening and metering stage are shown in Equation 20: ； Among them, AE i The power consumption of the i-th device per ton of final product packaged, in kW·h / t.

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