The necessity of the research It is therefore an obligation for the major of organizations under the iron and steel sector in Vietnam to develop GHG Inventory, Emission Reduction Plan,
Background
General context
On November 1, 2021, Vietnam's Prime Minister pledged to achieve net-zero emissions by 2050 during COP26, emphasizing the use of domestic resources while seeking financial and technological support from developed countries as outlined in the Paris Agreement Since then, significant efforts have been made to fulfill this commitment, including the issuance of Decision 888/QD-TTg on July 25, 2022, which outlines tasks and solutions for reducing greenhouse gas (GHG) emissions The following day, Decision 896/QD-TTg was released, approving the National Strategy for Climate Change until 2050, which includes specific GHG reduction targets compared to the Business-As-Usual scenario.
Table 1.1: Emissions reduction targets compared to BAU for Vietnam Net-zero pathway
National wide Reduce 43.5% emissions Achieve net-zero emissions
Emissions does not exceed 457 million ton of CO2 equivalent (CO2e)
Emission stays below or does not surpass 101 million ton of
Reduce 43% of emissions, Emission stays below or does not
Reduce 63.1% of emissions, Emission stays below or does
Sectors 2030 2050 surpass 64 million ton of CO2e not surpass 56 million ton of
Land use and forestry sector
Reduce 70% of emissions and increase 20% of carbon removals,
Total emissions and removals achieve a minimum of -95 million ton of CO2e
Reduce 90% of emissions and boost carbon removals by 30%,
Total emissions and removals achieve a minimum of -185 million ton of CO2e
Emission stays below or does not surpass 18 million ton of CO2e
Emission stays below or does not surpass 8 million ton of
Emission stays below or does not surpass 86 million ton of CO2e
Emission stays below or does not surpass 20 million ton of
The level of emissions for facilities requires reducing emissions
Facilities with an annual greenhouse gas emission of 2,000 tons of CO2e or more are required to decrease their GHG emissions
Facilities with an annual emission of at least 200 tons of CO2e must reduce their greenhouse gas emissions
On January 7, 2022, the Vietnamese Government enacted Decree 06/2022/ND-CP, which focuses on mitigating greenhouse gas (GHG) emissions and protecting the ozone layer This decree outlines the requirements for conducting GHG inventories and reducing emissions for facilities in Vietnam that contribute to GHG emissions The organizations obligated to perform these inventories and reduction measures are specified in Decision 01/2022/QD-TTg, issued on January 18, 2022, which identifies the sectors and facilities subject to GHG inventory development.
Table 1.2: Cases for compulsory GHG inventory and GHG Emission Reduction Sector GHG-emitting facilities must carry out GHG inventory
The facility has an annual emission of ≥3,000 tons of CO2 equivalent
Thermal power plants, industrial production facilities with total annual energy consumption ≥ 1,000 tons of oil equivalent (TOE)
Transport service company with total annual fuel consumption ≥ 1,000 TOE
The commercial building has a total annual energy consumption of ≥ 1,000 TOE
The solid waste treatment facility has an annual operating capacity of ≥ 65,000 tons
Vietnamese GHG-emitting facilities may need to quantify their product emissions throughout the life cycle for exports to Europe due to the Carbon Border Adjustment Mechanism (CBAM), which began on October 1, 2023 Importers are required to complete their first reporting period by January 2024 The European Commission introduced the CBAM proposal in July 2021 to prevent carbon leakage caused by differing climate policies between non-EU countries and the EU's stringent climate measures The CBAM aims to enhance the EU's Emission Trading System (ETS) by issuing CBAM certificates to importers based on the emissions intensity of their goods, which must be purchased at a price equivalent to ETS certificates.
The Carbon Border Adjustment Mechanism (CBAM) targets imports of specific products and essential precursors associated with carbon-intensive production processes, which are highly susceptible to carbon leakage Key products affected include iron and steel, cement, aluminum, fertilizers, and electricity.
The Carbon Border Adjustment Mechanism (CBAM) is set to expand its coverage to include over half of the emissions within sectors governed by the Emissions Trading System (ETS) upon full implementation During its transitional phase, the CBAM will serve as a trial period, allowing buyers, manufacturers, and regulatory bodies to collaborate and gather essential data on embedded emissions This data will be crucial for refining the methodology in the final phase of the CBAM.
During its transitional phase, Vietnam's exports to the EU include various products affected by the Carbon Border Adjustment Mechanism (CBAM), with iron and steel being the most significant both in volume and value In 2022, Vietnam exported 1.37 million tons of iron and steel, generating around $1.5 billion A comprehensive study by the Energy Transition Partnership highlights the impact of CBAM on Vietnam's steel industry, predicting a production output decrease of approximately 0.8% by 2030 Furthermore, the study estimates a 51.2% reduction in export value to the EU, translating to about $1.1 billion by 2030.
The necessity of the research
Organizations in Vietnam's iron and steel sector are required to develop a Greenhouse Gas (GHG) Inventory, Emission Reduction Plan, and assess the carbon footprint of their products This initiative will help companies identify their emission sources and set reduction targets, ensuring compliance with reporting requirements that begin in January 2024 One manufacturer specializing in bolts and thread rods has been selected to implement the GHG inventory and quantify the carbon footprint of its export products, meeting the necessary criteria and exporting to the EU Thus, conducting a GHG inventory, establishing an Emission Reduction Plan, and calculating emissions are essential steps for this company.
1 Any information that can help in identifying the manufacturer are not disclosed due to commercial and confidential purposes
5 emission intensity for their products is an urgently requirement
This study examines a company that has implemented a robust Emission Monitoring System, which meets ISO standards and can be independently certified The system effectively records essential data for compliance with reporting requirements and facilitates the creation of an emission reduction plan in accordance with Vietnam's regulations and the Carbon Border Adjustment Mechanism (CBAM).
Research question and hypothesis
Based on the rationale of the study, the following research questions along with their corresponding hypotheses are developed as in Table 1.3:
Table 1.3 Research questions and hypotheses
How are the emission sources contributing to the current total GHG emissions of the studied iron and steel company?
The iron and steel company's emission sources can be identified and quantified in accordance with ISO 14064-1:2018 and ISO 14069:2013 These emissions can also be calculated using methodologies from the Intergovernmental Panel on Climate Change (IPCC) and other reputable sources, accurately reflecting the manufacturer's current greenhouse gas (GHG) inventory profile.
What are the carbon footprint values or the specific embedded emissions of the manufacturer’s bolts concerning their life cycle stages?
The carbon footprint of bolts can be monitored according to ISO 14067:2018 and reveals the contribution of the products to GHG emission throughout different life cycle stages of the products
The following objectives and tasks along with their corresponding outputs and results have been introduced as Table 1.4:
Table 1.4 Research objectives and tasks
O1: To identify emission sources and calculate the total emissions and to perform analysis of the emission profile’s hot spots
T1: Identify emission sources of the manufacturer according to criteria from standards’ criteria
OP1: Emission sources of the manufacturer
Inventory of the manufacturers with uncertainty and key category analysis of their emission’s profile
T2: Establish methods for monitoring the emission sources of the studied iron and steel manufacturer
OP2: Methods for calculation of the emission sources
T3: Collect activity data, emission factors, and uncertainty values for according to the selected methods
OP3: Database of the emission sources
T4: Conduct GHG Inventory for the manufacturer
OP4: GHG emission results of the manufacturer
T5: Conduct uncertainty analysis for GHG Inventory
OP5: Uncertainty results of each emission source
OP6: Key emission sources and gases that significantly contribute to the manufacturer’s GHG emissions profile
O2: To quantify carbon footprint of the
T7: Select the product(s) of the manufacturer
OP7: Selected product(s) for carbon footprint calculation
R2: Carbon footprint of the manufacturer’s products and
Objective Task Outputs Results manufacturer’s products and to perform sensitivity analysis
Category Rule (PCR) according to the standard’s criteria
PCR for conducting a study on carbon footprint of product(s) sensitivity analysis
T9: Define the scope of the selected product(s) life cycle stages
OP9: The scope regarding life cycle stage of the product(s)
(cradle-to-gate, cradle-to-gate, etc.)
T10: Life cycle inventory of the product(s), can be combined with T3
OP10: Life cycle inventory results of the product(s)
T11: Life cycle impact assessment of the product(s)
OP11: Life cycle impact assessment results of the product(s)
T12: Sensitivity analysis of the results based on the standard’s criteria
OP12: Sensitivity analysis results of the carbon footprint study
Objectives and scope of the research
Objectives of the research
- To identify emission sources and calculate the total emissions and to perform analysis of the emission profile’s hot spots
- To quantify carbon footprint of the manufacturer’s products and to perform sensitivity analysis.
Scope of the research
- Study site: the company’s manufacturing (bolts and thread rod) plant
- Duration: eight (08) months (from November to June, 2024) The period for GHG Inventory and Carbon footprint calculation is the year 2023
The timeline of the research is shown in Figure 1.1
Literature review
The iron and steel sector worldwide and its related GHG emissions
Steel is produced globally and traded in various semi-finished and finished forms Crude steel, the solid state of steel after it has cooled from liquid, is essential for further processing or sale In 2022, global crude steel production reached 1,885 million tonnes, marking a 3.92% decline from 2021 but a slight increase of 0.15% compared to 2018 China leads the world in crude steel production, contributing around 54% with 1,018 million tonnes, followed by India at 125.3 million tonnes and Japan at 89.2 million tonnes.
According to the IEA's 2020 Steel Roadmap report, global demand for steel is projected to increase by more than 33% by 2050, driven by various policies and sustainable development scenarios.
Figure 1.2: Global steel demand for final use scenarios (IEA, 2020)
The Covid-19 pandemic has significantly impacted global supply chains, leading to an anticipated 5% decline in worldwide crude steel production from 2019 to 2020 In contrast, the People's Republic of China has managed to counter this global trend.
Steel production is anticipated to increase in 2020, fueled by high output levels during the first half of the year After a brief global downturn, the steel industry is expected to rebound and experience significant growth, according to baseline projections from the IEA (2020).
The steel industry is the largest consumer of coal, relying on it for approximately 75% of its energy needs, as it is essential for generating heat and producing coke for the conversion of iron ore into steel (Duda & Fidalgo Valverde, 2021) Steel is highly sustainable, with a global recycling rate surpassing 70% (Bjửrkman & Samuelsson, 2014), making it the most recycled material in the world Furthermore, 97% of by-products from steel production can be reused, with slag often repurposed for concrete manufacturing (Kobe Steel, LTD, 2021; Yi et al., 2012).
Figure 1.3: Utilization of steel slag (Gao et al., 2023)
The steel industry is a significant player in the global energy landscape, accounting for around 20% of industrial energy consumption and approximately 8% of total energy use (IEA, 2020) In 2019, it generated about 2.6 gigatonnes of carbon dioxide emissions, representing 7% of the energy sector's total emissions worldwide (IEA, 2020) Without targeted measures to mitigate these impacts, the environmental footprint of steel production will continue to pose challenges.
11 demand for steel when possible and update the current production facilities, carbon dioxide emissions are expected to keep rising, reaching 2.7 gigatonnes per year by 2050
- an increase of 7% compared to the year 2020 levels - even with a larger share of secondary production methods that require less energy (IEA, 2020)
The iron and steel sector has significant potential for reducing emissions, particularly given the projected increase in demand Key strategies to lower CO2 emissions include improving energy efficiency and adopting advanced technologies such as coke dry quenching, high-strength coke production for enhanced hydrogen reduction in blast furnaces, and implementing Top-pressure Recovery Turbine (TRT) technology Additionally, utilizing dry dedusting systems for blast furnace gas (BFG) and converter off-gases (BOFG), along with CO2 capture, storage, and utilization, are crucial measures for sustainable practices in this industry.
The iron and steel sector in Vietnam and its related GHG emissions
Vietnam has been a significant player in crude steel manufacturing for over 60 years, ranking thirteenth in global production with an output of approximately 20 million tons in 2022 The production methods include Blast Oxygen Furnace and Electric Arc Furnace, contributing around 13 million tons and 7 million tons, respectively However, in the first half of 2023, Vietnam's steel production dropped to 13.1 million tons, reflecting a 20.9% year-over-year decrease This decline is primarily attributed to weak demand in the real estate market, exacerbated by high interest rates and ongoing real estate bond issues from 2022.
In 2022, Vietnam exported approximately 8.397 million tons of steel, representing a 35.85% decrease from 2019, with a total export value of 7.99 billion USD, down 32.2% from the previous year (Vietnam Steel Association, 2023) The primary destinations for these exports included ASEAN countries (42%), Europe (16%), the US (8%), and South Korea (6%) In the first five months of 2023, Vietnam continued its steel exports, shipping about 4.3 million tons.
12 steel (+10.12% YoY) Export value reached 3.4 billion USD, down -16.21% YoY (Shinhan Securities Vietnam, 2023)
Figure 1.4: Top 10 export markets of Vietnam steel products in 2022 (Vietnam Steel
In 2022, Vietnam imported 11.679 million tons of finished steel products valued at over 11.92 billion USD, marking a 5.62% decrease in volume but a 3.04% increase in value compared to the previous year (Vietnam Steel Association, 2023) However, in the first five months of 2023, imports fell to approximately 4.6 million tons worth 3.9 billion USD, reflecting a year-on-year decline of 12.3% in volume and 29.6% in value (Shinhan Securities Vietnam, 2023).
Nevertheless, steel industry in Vietnam witnessed the prosperity in the fourth quarter of
In the fourth quarter of 2023, steel prices and purchasing power saw a recovery, positively impacting many businesses, including Hoa Phat Group, which produced 648,000 tons of crude steel in December The consumption of hot rolled coil (HRC) steel products, construction steel, and steel billets reached 760,000 tons, reflecting a 7% increase Notably, building steel and high-end steel accounted for 462,000 tons, representing a 13% rise compared to November 2023.
High-end steel prices have reached their peak in the last 20 months, reflecting a resurgence in the domestic market driven by both private sector and public investment projects, which are showing increasingly positive signs after a prolonged period of inactivity.
In Vietnam, the iron and steel production sector emitted 3.858 Mt CO2e, while fuel combustion activities in this industry contributed an additional 8.757 Mt CO2e, according to the National GHG Inventory in 2016 To comply with Vietnam's regulations and the Carbon Border Adjustment Mechanism (CBAM), it is essential to assess GHG emissions from steel companies and develop a suitable emission reduction plan.
Overview of the nuts and bolts manufacturing
Nuts and bolts are crucial elements in engineering and construction, with their manufacturing process evolving into a sophisticated and technologically advanced procedure that includes multiple stages It begins with cold forging to shape steel wire, followed by heat treatment to enhance strength, and concludes with surface treatment for improved resilience The finished products are then packaged for shipping, and more intricate bolt designs may require additional manufacturing steps.
Cold forging is a metal shaping process performed at room temperature using compressive forces, beginning with large steel wire rods that are cut to length and standardized according to ISO 898-1 specifications The wire is then shaped into the desired form through specialized tools that apply high pressure, forcing the steel through a series of dies For more intricate nut and bolt designs, additional processes such as turning and drilling may be required; turning involves rotating the bolt at high speeds to refine its shape, while drilling creates necessary holes Some bolts may also incorporate washers during this stage Major industrial manufacturers commonly utilize heat treatment, exposing bolts to high temperatures to enhance their properties.
Threading of steel is typically performed before heat treatment while the material remains malleable, utilizing either rolling or cutting techniques The rolling method, similar to cold forging, shapes the threads by passing the bolt through a die, whereas the cutting method involves removing steel to create the threads (Rosso et al., 2015).
CBAM reporting requirements for the iron and steel sector
CBAM goods are products imported into European countries from sectors such as steel, aluminum, specific chemicals, cement, and electricity (European Council, 2023b) Reporting these goods entails several requirements, with a key focus on monitoring the direct emissions produced by each installation.
Organizations must monitor and inform clients about the emissions linked to specific input resources, known as "precursors," used in the manufacturing process Evaluating the embedded emissions of these precursor materials is crucial for transparency and sustainability.
To comply with CBAM requirements, it is essential to calculate the indirect emissions from imported electricity used in manufacturing across all sectors Additionally, any emissions embedded in precursor materials must be considered when relevant (European Council, 2023a).
Quantification of carbon footprint of iron and steel products
A recent sustainability report by the World Steel Association highlights the carbon intensity of the steel industry based on various production technologies In 2022, the CO2 emissions intensity for the Blast Furnace - Basic Oxygen Furnace (BF-BOF) method was 2.33 tons of CO2 per ton of crude steel, while the Scrap - Electric Arc Furnace (Scrap - EAF) and Direct Reduced Iron - Electric Arc Furnace (DRI - EAF) methods recorded lower emissions at 0.66 and 1.39 tons, respectively The overall global average CO2 emissions intensity for crude steel production stands at 1.91 tons of CO2 per ton, reflecting the varying impacts of different steel production technologies.
A recent study utilizing life cycle assessment reveals that the carbon footprint for crude steel in China's steel industry is 2.33 tCO2/t, accounting for raw material procurement, steel processing, manufacturing, transportation, and disposal (Song et al., 2023) In the EU, a case study found that the carbon footprint for hot-rolled coil (HRC) steel, using a recycled content approach, is 2.1 tCO2eq, focusing on raw material acquisition and steel production (Suer et al., 2021) Additionally, the European Commission's Joint Research Center has provided assessments of greenhouse gas emission intensities across four energy-intensive sectors, including iron and steel, which supports the implementation of the Carbon Border Adjustment Mechanism (CBAM) (European Commission Joint Research Centre, 2023) The report categorizes emission intensity values for the steel industry based on direct and indirect emissions and includes data for 16 non-EU countries and the EU 27, differentiated by Combined Nomenclature codes.
Currently, there are no studies quantifying the carbon footprint of steel manufacturers in Vietnam This thesis aims to introduce a platform that enables Vietnamese steel companies to calculate and report the carbon footprint of their steel products.
Research methodology
An introduction of the studied iron and steel manufacturer
This case study examines the greenhouse gas emissions inventory and carbon footprint of a Vietnamese company specializing in the production of iron and steel products, specifically bolts and thread rods Situated on 6.7 hectares of land, the manufacturer focuses exclusively on exporting its products, with bolts being the only items sent to the EU market Consequently, the study specifically calculates the carbon footprint of bolts in accordance with the EU's CBAM Regulation.
The primary materials used in bolt production are rolled coil steel, along with various chemical compounds tailored for different bolt types The manufacturing process is organized into sequential unit processes, as illustrated in Example Figure 2.1 In accordance with ISO 14067:2018, a unit process is defined as the smallest element in life cycle inventory analysis, where both input and output data are quantified (International Organization for Standardization, 2018a).
Figure 2.1: Example of a set of unit processes within a product system (International
The unit process for manufacturing bolts is as in Figure 2.2:
Figure 2.2: Unit processes in bolts manufacturing
Methods
The GHG Inventory and carbon footprint of products will be conducted in accordance with ISO 14064-1:2018 and ISO 14067:2018 standards A key category analysis will assess the manufacturer's emissions profile to pinpoint the primary emission sources, facilitating effective resource allocation for mitigation efforts (IPCC, 2019c) Additionally, a sensitivity analysis will be performed on the carbon footprint results to determine the key factors influencing these values.
The overall methodology relating to the framework of this thesis is presented as in Figure 2.3:
Data collection and validation (M1)
Data will be gathered from primary sources through the manufacturer's inventory activities and recording systems Interviews will be conducted to validate this data and assess staff awareness, strategies, and proposed initiatives for emission reduction, which will be valuable for subsequent research activities Detailed data collection activities are outlined in Table 2.1.
Data collection and validation Name of method Activity
Gather and analyze historical data from websites regarding emissions in the iron and steel sector, focusing on production process emissions and the emission intensity values of the products.
Related activities: Data collection, analysis, synthesis, and assessment
Data collection and validation Name of method Activity
Disseminate questionnaires to identified data from supply chain of the manufacturer:
- Suppliers: questionnaire for getting the information of carbon footprint of crude steel, distance of upstream transportation, and solid waste treatment method have been sent to related suppliers;
- Clients: questionnaire for getting the information of the use stage of the bolts have been sent to related clients
Site visit for data validation and interviews
Visit the manufacturer site to validate the data provided and interview them for their awareness of, strategies for or initiatives to reduce emissions
Collected data will be compiled and processed for analysis Microsoft Excel software will be used.
Monitoring of the emissions based on ISO 14064-1:2018 and ISO/TR 14069:2013 (M2)
Emission sources will be identified following the guidelines set by ISO 14064-1:2018 and ISO/TR 14069:2013 Subsequently, the identified emission sources will be quantified in accordance with the IPCC Guidelines for National Greenhouse Gas Inventories.
(2019 Refinement, 2013 Supplements, and 2006 versions) as well as other suitable methods such as GHG Protocol, US EPA, etc
The GHG Inventory process are described in Figure 2.4:
Figure 2.4: GHG Inventory process (International Organization for Standardization,
A common methodological approach combines activity data (AD), which measures the level of human activity, with emission factors (EF) that quantify emissions or removals based on these activity levels (IPCC, 2006c) This relationship can be summarized in a fundamental equation that links activity levels to their environmental impact.
All greenhouse gas (GHG) calculations must be expressed in Carbon Dioxide equivalent (CO2e) using the most recent Global Warming Potential (GWP) values from the IPCC In accordance with ISO 14064-1:2018, the GWP value utilized should be GWP-100 This thesis utilizes GWP values from the IPCC's Sixth Assessment Report (2023) to meet these standards.
The operational boundary has been chosen as the operational control approach, in which the manufacturer accounts for all the GHG emission sources that are under their operational control
GHG emissions at the manufacturer are categorized according to ISO 14064-1:2018, which includes direct GHG emissions and removals from activities within an organization's control These emissions primarily stem from combustion processes.
Indirect greenhouse gas (GHG) emissions can be categorized into several sources: a) emissions from fuels used for fixed or non-fixed equipment; b) emissions from imported energy related to fuel combustion during energy generation; c) emissions from transportation activities, primarily from fuel burned in mobile equipment outside the manufacturer; d) emissions linked to the use of products and services post-manufacturing; e) emissions associated with the utilization of the manufacturer’s products; and f) emissions from other sources that do not fit into the aforementioned categories.
Emission sources have been identified following ISO 14064-1:2018 and ISO 14069:2013 standards, which mandate the quantification of all direct emissions and removals Additionally, the organization will assess and calculate significant indirect emissions based on established criteria outlined in Table 2.2.
Table 2.2: Criteria for determining significant indirect emission sources
Relation to GHG targets of the organization (B) 25%
The availability of activity data (C) 20%
High, data is directly collected from the organization 3
Medium, data is collected from supply chain or literature 2
Low, data is only estimated based on assumptions 1
Readily available For the raw material supply, the emission factor from the supplier itself applies 3
For service provision industries, international emission factors are used 2
There is no specific emission factor, only relative emission factor can be applied There is an emission factor but costs are incurred for collection
The magnitude of the emission sources (F) 15%
The significant level is then calculated as equation (2):
The direct and indirect GHG emission sources that have been found significant along with the calculation methods are as Table 2.3:
Table 2.3: GHG emission categories and the calculation methods
Emission sources according to ISO
Identified sources at the organization GHGs Calculation methods Category 1 a) Stationary combustion
- Diesel Oil (DO) for Generators
- Liquified Petroleum Gas (LPG) for Heat treatment and Drying
- DO for on-road CO2,
- Burning Methanol for heating; CO2 Stoichiometry of burning methanol d) Fugitive emissions
- Domestic wastewater treatment system CH4, N2O
Chapter 6, Volume 5, IPCC 2006 and IPCC
- CO2 fire extinguishers CO2 Equation in (1)
- Refrigerants HCFC-22 Equation in (1) e) LULUCF - Cropland converted to settlements CO2
Volume 4, IPCC 2006 and IPCC 2019 (IPCC, 2006a), (IPCC, 2019a)
Category 2 a) Imported electricity - Electricity imported from EVN grid Equation in (1)
Category 3 a) Upstream transport and distribution for goods
- Transport of the main materials: roan, maritime, and air Equation in (1) b) Business travel - Business travel: air Equation in (1)
Category 4 a) Goods purchased by an organization
- Main materials: rolled coil steel, bar rod, carton, etc Equation in (1) b) Capital goods that are purchased and amortized by the organization
- Main equipment, facilities, and vehicles Equation in (1)
Volume 5, IPCC 2006 and IPCC 2019 (IPCC, 2006e) (IPCC, 2019e)
Category 5: - Determined as not significant by the organization Category 6: - Not available
*Only Category 1 is required to quantify each GHG in every emission sources by ISO standard
The uncertainty analysis is performed according to Chapter 3, Volume 1 IPCC 2006 and IPCC 2019 (IPCC, 2006c), (IPCC, 2019c), using Approach 1: propagation of error
Basic methods for estimating emissions typically involve multiplying activity data (AD) by an emission factor (EF), as outlined in Equation (1) The uncertainty linked to these emissions can be determined using Approach 1, which is represented as AD*EF (IPCC, 2019c).
𝑈 𝑒𝑚𝑖𝑠𝑠𝑖𝑜𝑛𝑠 = √𝑈 𝐴𝐷 2 + 𝑈 𝐸𝐹 2 (3) in which U denotes the percentage uncertainty of each parameter
When adding or subtracting uncertain quantities, a straightforward equation can be formulated to determine the percentage uncertainty of the resulting sum, as outlined in Approach 1 of the IPCC (2019c).
|𝑥 1 +⋯+𝑥 𝑖 +⋯+𝑥 𝑛 | (4) in which U denotes the percentage uncertainty of each parameter; xi denotes quantities to be combined; xi may be a positive or negative number.
Quantification of the carbon footprint of product(s) based on ISO 14067:2018 (M3)
The carbon footprint will be evaluated and measured in accordance with ISO 14067:2018, which outlines the requirements and guidelines for quantifying greenhouse gases related to products The methodology for assessing the carbon footprint of products, as per ISO 14067:2018, is illustrated in Figure 2.5.
Figure 2.5: Carbon footprint quantification process a Use of CFP-PCR (Product Category Rules)
ISO 14067:2018 outlines the Product Category Rules (PCR), which are essential for developing Type III environmental declarations and carbon footprint communications for similar product categories Organizations must adopt existing relevant PCR or Carbon Footprint Product Category Rules (CFP-PCR) In the absence of applicable CFP-PCR, they should refer to other globally accepted sector-specific documents that align with ISO 14067:2018 requirements The selected PCR is detailed in the subsequent chapter.
4 of this thesis b Life Cycle Assessment method
After selecting PCR, the Life Cycle Assessment (LCA) method will be executed in four stages, concentrating specifically on the climate change impact category, as illustrated in Figure 2.5 The summary of the LCA stages is presented in Figure 2.6.
Figure 2.6: LCA framework (International Organization for Standardization, 2006b)
Key categories and sensitivity analysis (M4)
This analysis utilizes the findings from the GHG Inventory and carbon footprint quantification to pinpoint emission hotspots and propose effective emission reduction initiatives or programs for manufacturers.
The key categories analysis is performed separately for direct and indirect emission sources, according to the methodology in Chapter 4, Volume 1, IPCC 2006 and IPCC
2019 (IPCC, 2006c), (IPCC, 2019c) The cumulative threshold for key categories is 95%, start combining from the largest source to the smallest source of emissions
Sensitivity analysis involves systematic procedures to evaluate the influence of various emission sources on the carbon footprint of bolts throughout their entire life cycle (International Organization for Standardization, 2018a) By utilizing sensitivity coefficients, researchers can assess how changes in specific factors impact greenhouse gas (GHG) emissions (Guan et al., 2016) These coefficients provide a quantitative measure of the relationship between different variables and their effect on emissions.
(5) where 𝜔 represents the sensitivity coefficient, x stands for the impacting factors, Δx
27 represents the small change in the x parameter, and 𝑓(𝑥 1 , … , 𝑥 𝑖 , … , 𝑥 𝑛 ) signifies the CFP throughout their life cycle.
Data and calculations
Data and calculation for GHG Inventory
a Direct emissions - Stationary combustion and mobile combustion
For the identified sources of combustion, activity data and emission factors are as Table 2.4:
Table 2.4: Data for GHG Inventory from combustion sources
Emission sources Activity data Emission factors with references
Diesel Oil (DO) for Generators
- Net calorific value: 43 TJ/Gg (IPCC, 2006b)
- CH4: 3 kg/TJ (IPCC, 2006b); GWPCH4: 27.9 (Intergovernmental Panel On Climate Change (Ipcc), 2023), use for all CH4 emissions
273 (Intergovernmental Panel On Climate Change (Ipcc), 2023), use for all N2O emissions
- DO density: 1205 liters/ton (United Kingdom, 2023)
(LPG) for Heat treatment and
- Net calorific value: 47.3 TJ/Gg (IPCC, 2006b)
- Net calorific value: 43 TJ/Gg (IPCC, 2006b)
Emission sources Activity data Emission factors with references
DO for on-road vehicles
- Net calorific value: 43 TJ/Gg (IPCC, 2006b)
Motor gasoline consumption in 2023: 8,646 liters
- Net calorific value: 44.3 TJ/Gg (IPCC, 2006b)
For combustion sources, the AD will be converted to Gigagram (1 Gigagram equals
To convert diesel oil (DO) consumption from metric tons to liters, a density of 1205 liters/ton is used (United Kingdom, 2023) The annual demand (AD) is then multiplied by the net calorific values of the relevant fuels to report energy-related data in standardized units This conversion into energy units, such as terajoules (TJ), requires the application of calorific values Emission calculations for CO2, CH4, and N2O are performed by multiplying AD with their respective emission factors (EFs), and all emissions are expressed in terms of tCO2e using Global Warming Potential (GWP) values An example calculation for diesel oil used in generators is provided in Table 2.5.
Table 2.5: Calculation steps for direct emissions: stationary and mobile combustions
1: Converting the DO consumption from liters to Gg
2: Converting the DO consumption from Gg to
(with GWP for GHGs that are not CO2)
- Direct emissions – Industrial process emissions:
The assessment of chemicals that produce greenhouse gas (GHG) emissions involves a thorough review of the Material Safety Data Sheets (MSDS) for each substance This evaluation specifically highlights the emissions associated with the combustion of methanol (CH3OH) The emissions generated from burning methanol are calculated using stoichiometric principles, providing insight into its environmental impact.
2CH3OH + 3O2 => 2CO2 + 4H2O Accordingly, 1 kg of Methanol burnt emits 1.375 kg of CO2 emissions
- Direct fugitive emissions from the release of GHGs in anthropogenic systems
For the identified sources of fugitive emissions, activity data and emission factors are as Table 2.6:
Table 2.6: Data for GHG Inventory from fugitive sources
Emission sources Activity data Emission factors
- CH4 for septic tanks: 0.3 kg CH4 / kg BOD (IPCC, 2019e)
- Septic tanks - CH4 emission: numbers of working day and visitors in 2023: 559,015 days,
- Anaerobic system – CH4 emission: BOD input and output
- Aerobic system – N2O emission: Total N input and output
- CH4 for anaerobic system: 0.48 kg
- Country-specific per capita BOD5:
CO2 fire extinguishers consumption in 2023 N/A Refrigerants
Refrigerants consumption in 2023: HCFC-22 consumption: 269.70 kg
(Intergovernmental Panel On Climate Change (Ipcc), 2023)
Direct emissions and removals from land use, land use change, and forestry (LULUCF) are linked to actions that modify carbon stocks over a 20-year period Manufacturers have the option to either assess the overall changes in carbon stock or evaluate emissions on an annual basis.
AD and EF are chosen as below:
Type of land at the manufacturer site:
Area of the converted land, numbers of planted tree, type of soil, and land management information
The values are from Volume 4, IPCC 2006 and IPCC 2019 (IPCC, 2006a), (IPCC, 2019a)
C stock in biomass before transition: 4.7 tonnes C/ha b Significant indirect emissions
From using equation in (2), significant indirect emissions have been identified and their related AD and EF are as Table 2.7:
Table 2.7: AD and EF of significant indirect emissions Emission sources Activity data Emission factors
Electricity Electricity Emission factor of Viet Nam electricity
Emission sources Activity data Emission factors imported from
2023 grid: 0.7221 tCO2 / MWh (Department of Climate Change, MONRE, 2022)
Transport of the main materials: road, maritime, and air
Arrival and destination points, transported weights
The emission factors are from the Department of Energy Security & Net Zero, United Kingdom (United Kingdom,
2023) Road: 0.09696 kg CO2e / ton*km Maritime: 0.01321 kg CO2e / ton*km Air transportation: 1.09903160402685 ton*km
Airport locations and number of staff
Air travel: 0.0794733303087248 kg CO2e /passenger*km (United Kingdom, 2023) Main materials: rolled coil steel, bar rod, carton, etc
The emission factors are from the suppliers, as well as national and international publication
Main equipment, facilities, and vehicles
Types and quantities, price, purchasing date and amortization of asset
The emission factors are from the suppliers, as well as national and international publication
- Equipment used for manufacturing: 0.266 kgCO2e/USD (Ingwersen, 2023);
- Facilities: 508.57 kg CO2e / m 2 (Rodrigues et al., 2018)
Types and quantities of wastes, treatment methods
The emission factors are from Volume 5, IPCC 2006 and IPCC 2019 (IPCC, 2006e), (IPCC, 2019e)
Wastewater volume from the organization
Wastewater treatment outside: 0.201318291710656 kgCO2e /m 3 (United Kingdom, 2023) c Data for uncertainty analysis
The uncertainty analysis for each emission source and greenhouse gas (GHG) is conducted individually and subsequently integrated to form the overall emission profile of the manufacturer, following the methodologies outlined in Chapter 3, Volume 1 of the IPCC 2006 and 2019 reports.
(IPCC, 2019c) The uncertainty values for activity data and emission factors are from Viet Nam Third Biennial Updated Report to the UNFCCC (Vietnam, 2020) The data is collected as Table 2.8:
Table 2.8: Data for uncertainty analysis (Vietnam, 2020)
Emission sources AD uncertainty values
Diesel Oil for Generators - CO2 +/- 17.5% +/- 7.0%
Diesel Oil for Generators - CH4 +/- 17.5% +/- 60.0% Diesel Oil for Generators - N2O +/- 17.5% +/- 60.0%
Liquified Petroleum Gas for Heat treatment and
Liquified Petroleum Gas for Heat treatment and
Liquified Petroleum Gas for Heat treatment and
Diesel Oil for Forklifts - CO2 +/- 2.5% +/- 3.5%
Diesel Oil for Forklifts - CH4 +/- 2.5% +/- 20.0%
Diesel oil used in forklifts and on-road vehicles emits various greenhouse gases, including N2O, CO2, and CH4, with emissions levels typically varying by +/- 2.5% to +/- 25.0% Specifically, diesel oil for on-road vehicles shows CO2 emissions of +/- 2.5% and CH4 emissions of +/- 2.5%, while motor gasoline for on-road vehicles has similar CO2 and CH4 emission levels Additionally, burning methanol for heating results in CO2 emissions that can fluctuate by +/- 8.9% to +/- 22.3% Understanding these emissions is crucial for addressing environmental impacts and improving fuel efficiency.
Domestic wastewater treatment system: Septic tank - CH4
Emission sources AD uncertainty values
Cropland converted to settlements - CO2 +/- 15.0% +/- 60.0% Electricity imported from EVN grid - CO2e +/- 7.5% +/- 7.0%
Transport of the main materials: maritime -
Transport of the main materials: road - CO2e +/- 2.5% +/- 3.5% Transport of the main materials: air - CO2e +/- 5.0% +/- 2.5%
Main materials: rolled coil steel, bar rod, carton, etc - CO2e +/- 8.9% +/- 22.3%
Main equipment and vehicles - CO2e +/- 17.5% +/- 7.0%
Waste treatment by contractors: Incineration -
Waste treatment by contractors: Incineration –
Waste treatment by contractors: Biological treatment – CH4
+/- 40.0% +/- 4.0% Wastewater treatment by The Industrial Zone -
Data and calculation for carbon footprint of products
The manufacturer has dedicated a separate facility for the production of bolts and thread rod products, with bolts being the sole export item, while thread rods serve the domestic market The carbon footprint assessment focuses on bolts, as their manufacturing process involves only electricity and certain chemicals, allowing for distinct tracking of electricity use and steel consumption For shared emission sources, emissions are allocated based on the production capacity of both bolts and thread rods, following the Product Category Rule (PCR) guidelines.
This study adheres to the principles of product classification outlined in industry standard EN 15804:2012+A2:2019/AC:2021, focusing on the sustainability of construction works and environmental product declarations It also aligns with ISO 14067:2018 for quantifying carbon footprints The primary product analyzed for carbon footprint quantification is bolts, which are significantly exported to the EU.
The data for quantification of carbon footprint is collected for the full calendar year of
2023 The declaration unit for the carbon footprint of bolt will be one ton of bolt
The product's system boundary is defined as Cradle-to-Gate, encompassing the extraction and distribution of raw materials up to the point of manufacturing, while excluding aspects such as distribution to retailers, product utilization, disposal, and recycling.
The EN 15804:2012+A2:2019/AC:2021 standard incorporates additional out-of-gate machining and finishing processes This study utilizes emission factors from various sources, including suppliers and literature, to assess the extraction and distribution of raw materials The production process of rolled coil steel yields outputs such as bolts and thread rods A visual representation of the life cycle stages within the Cradle to Gate system boundary is provided below.
Figure 2.7: System boundary of the carbon footprint of products
The cut-off criteria according to EN 15804:2012+A2:2019/AC:2021 applied for input materials of the manufacturing process are as Table 2.9:
1 Material flows into the unit process that account for less than 1% will be removed from the study system
2 Energy flows into the unit process that account for less than 1% will be removed from the study system
3 The total amount removed of incoming matter/energy flows should not exceed 5% per unit process
4 Energy/material flows that cause GHG emissions directly during the process of the unit are required to be included in the calculation
GHG Inventory of the manufacturer
Category 1: Direct emissions and removals
a Direct emissions: stationary and mobile combustions
Stationary combustion emissions arise from burning fuels in fixed equipment to generate heat, mechanical energy, and steam.
Emissions from mobile combustion occur when fuel is ignited in non-fixed equipment, which encompasses both off-road and on-road vehicles (IPCC, 2006b)
Following steps in Table 2.5, emissions from combustion are as Table 3.1:
Table 3.1: Results of emissions from stationary and mobile combustion
Emission sources GHG Amounts (tCO 2 e)
Diesel Oil (DO) for Generators
Liquified Petroleum Gas (LPG) for Heat treatment and Drying
DO for on-road vehicles
When fossil fuels are combusted, hydrogen and carbon atoms react with oxygen, primarily producing water vapor (H2O), carbon dioxide (CO2), and heat energy (Andres et al., 2012) While most carbon is released as CO2 during combustion, some is emitted as carbon monoxide (CO), methane (CH4), or non-methane volatile organic compounds (NMVOCs), which eventually convert to CO2 in the atmosphere (IPCC, 2006b) The emissions of non-CO2 gases during fuel burning typically contain much lower levels of carbon compared to CO2 emissions, a trend also observed in the manufacturer studied (Table 3.1).
Calculating CO2 emissions based on the total carbon content of combusted fuel provides greater accuracy, as this measurement is directly tied to the fuel itself In contrast, the emissions of non-CO2 gases are affected by a range of factors, including technology and maintenance practices, which are often less clearly understood (Andres et al., 2012) This approach also encompasses direct emissions from industrial processes, fugitive emissions, and land use, land-use change, and forestry (LULUCF).
Industrial processes encompass the transformation of raw materials and components into finished goods, typically occurring in manufacturing facilities These processes vary significantly across different industries, tailored to meet specific production needs One notable example in manufacturing is the burning of methanol, which has been identified as a key operation.
Direct fugitive emissions arise from various sources, including the extraction, processing, storage, and delivery of fossil fuels, as well as leaks from equipment such as air conditioners Agricultural activities contribute to these emissions through processes like decay, fermentation, manure management, livestock raising, and the use of nitrogen fertilizers Additionally, unmanaged waste decomposition in landfills and composting sites further exacerbates the issue.
38 wastewater treatment plants, and other waste management operations (IPCC, 2019b), (IPCC, 2019d), (IPCC, 2019e) For the manufacturer, domestic wastewater treatment system, CO2 fire extinguishers consumption, and refrigerant recharged have been identified
According to the IPCC guidelines (2006, 2019), emissions are assessed across six land-use categories: grassland, cropland, wetland, forest land, settlement, and other land, as well as various carbon storage areas, including above and below-ground biomass, dead organic matter, and soil organic matter Carbon storage can change during land-use transitions, such as converting forests into other land types, or even within the same land-use category Notably, emissions from cropland converted to settlements have been identified as a significant source for manufacturers.
The results of quantifying these sources are as Table 3.2:
Table 3.2: Industrial processes, Fugitive emissions, and LULUCF
Emission sources GHG Amounts (tCO 2 e)
Methanol is utilized as a feedstock in chemical conversion processes, primarily for the production of organic chemicals, distinguishing its burning from stationary combustion methods (IPCC, 2006d).
Wastewater can generate CH4 through anaerobic treatment or disposal and can also emit
N2O However, the IPCC Guidelines do not take CO2 emissions into account from wastewater, as these emissions are biogenic and thus excluded from the total emissions calculations (IPCC, 2006e)
Wastewater and its sludge can produce methane through anaerobic degradation, with the quantity of methane generated largely dependent on the degradable organic material (DOM) present, along with temperature and treatment technology (Parravicini et al., 2016) The primary factor influencing methane production is the amount of DOM To quantify the organic material in wastewater, parameters such as Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) are utilized (IPCC, 2006e; IPCC, 2019e).
Nitrous oxide (N2O) is produced through the breakdown of nitrogen compounds in wastewater, as noted by the IPCC (2006e) Centralized wastewater treatment systems utilize a range of methods, from lagoons to advanced tertiary technologies, to effectively remove these nitrogen compounds The treated effluent is typically discharged into water bodies such as rivers, lakes, or estuaries N2O emissions can occur during the nitrification and denitrification processes, which may happen both within the treatment facility and in the receiving water body (Law et al., 2012).
For the manufacturer, their domestic wastewater treatment system includes both anaerobic and aerobic tanks, therefore, CH4 and N2O emissions have been calculated and included in the emission profile.
Significant indirect emissions (Category 2, 3, and 4)
Category 2 emissions include encompasses solely GHG emissions from fuel combustion linked to the production of final energy and utilities It does not include cradle emissions (from the fuel's origin to the energy manufacturer gate), emissions from power plant construction, or emissions attributed to transport and distribution losses For the manufacturer, indirect emission from electricity imported has been identified
Category 3 emissions are GHG emissions that stem from sources beyond the
The organization's boundaries encompass primarily mobile sources, particularly emissions from fuel consumed in transportation equipment Significant indirect emissions arise from upstream transportation—via sea, road, and air—from suppliers to manufacturers, as well as from business travel by air, as calculated using the specified equation.
Category 4 GHG emissions originate from sources beyond the organization's boundaries that are linked to the products utilized by the manufacturer For the manufacturer, indirect emissions from purchased goods that are product-related, capital goods (main equipment and facilities), disposal of solid and liquid waste by contractors have been determined as significant using Equation in (2)
The results of quantifying these sources are as Table 3.3:
Table 3.3: Quantities of significant indirect emissions
Emission sources GHG Amounts (tCO 2 e)
Capital goods – main equipment CO2e 1,580.13
Solid waste treatment by contractor
To sum up, emission profile of the manufacturer will be reported according to the requirement of ISO 14064-1:2018 as Table 3.4:
Table 3.4: Summary of GHG Inventory of the manufacturer
Total of direct emissions and removal 3,497.59
Due to the nature of secondary products – bolts, indirect emissions dominate the emission profile, accounting for approximately 98%
Figure 3.1: Direct versus Indirect emissions
Over 98% of emissions from organizations are attributed to indirect sources, with over 70% stemming from the use of products (Category 4) Additionally, indirect emissions from electricity usage (Category 2) account for approximately 20%, while transportation-related indirect emissions (Category 3) contribute around 7% to the total emissions.
Key categories and uncertainty assessment of emission sources
Key categories analysis
Each source in the direct emissions with each GHG is separated for analysis Key categories for direct emissions are as Figure 3.3:
Figure 3.3: Key categories analysis for Direct GHG Emissions and Removals
The major contributors to direct emissions from manufacturers, as illustrated in Figure 3.3, include Liquified Petroleum Gas used for heat treatment and drying, burning methanol for heating, refrigerants, diesel oil for forklifts, domestic wastewater treatment systems, and the conversion of cropland to settlements, collectively accounting for over 95% of total emissions.
Similarly, key categories for indirect emissions are as follows:
The primary contributors to the Indirect Emissions of the manufacturer, as illustrated in Figure 3.4, are highlighted in red and collectively account for over 95% of total emissions These key categories include main materials such as rolled coil steel, bar rod, and carton, along with electricity sourced from the EVN grid and the transportation of these main materials via road.
Cummul at iv e co ntrib ution
Cumulative contribution Key category threshold
Figure 3.4: Key categories analysis for Indirect GHG Emissions
Uncertainty analysis
The result of the analysis using equations (3)Error! Reference source not found and
(4) with data from Table 2.8 is shown in Table 3.5:
Diesel Oil for Generators - CO2 +/- 18,8%
Diesel Oil for Generators - CH4 +/- 62,5%
Liquified Petroleum Gas for Heat treatment and Drying - CO2 +/- 18,8%
Liquified Petroleum Gas for Heat treatment and Drying - CH4 +/- 62,5%
Liquified Petroleum Gas for Heat treatment and Drying - N2O +/- 62,5%
Diesel Oil for Forklifts - CO2 +/- 4,3%
Diesel Oil for Forklifts - CH4 +/- 20,2%
Main materials: rolled coil steel, bar rod, carton, etc.
Electricity imported from EVN grid
Transport of the main materials: road
Main equipment, machinery, facilities, and vehicles
Transport of the main materials: maritime
Wastewater treatment by The Industrial Zone
Business travel: air Transport of the main materials: air
Cu mm ulativ e contrib uti on
Cumulative contribution Key category threshold
Diesel Oil for on-road vehicles - CO2 +/- 4,3%
Diesel Oil for on-road vehicles - CH4 +/- 20,2%
Diesel Oil for on-road vehicles - N2O +/- 25,1%
Motor gasoline for on-road vehicles - CO2 +/- 4,3%
Motor gasoline for on-road vehicles - CH4 +/- 20,2%
Motor gasoline for on-road vehicles - N2O +/- 25,1%
Burning Methanol for heating - CO2 +/- 24,0%
Domestic wastewater treatment system: Septic tank - CH4 +/- 23,5%
Domestic wastewater treatment system: Anaerobic tank - CH4 +/- 23,5%
Domestic wastewater treatment system: Aerobic tank – N2O +/- 60,8%
Cropland converted to settlements - CO2 +/- 61,8%
Electricity imported from EVN grid - CO2e +/- 10,3%
Transport of the main materials: maritime - CO2e +/- 25,0%
Transport of the main materials: road - CO2e +/- 4,3%
Transport of the main materials: air - CO2e +/- 5,6%
Main materials: rolled coil steel, bar rod, carton, etc - CO2e +/- 24,0%
Main equipment and vehicles - CO2e +/- 18,8%
Waste treatment by contractors: Incineration - CO2 +/- 64,0%
Waste treatment by contractors: Incineration – N2O +/- 78,1%
Waste treatment by contractors: Biological treatment – CH4 +/- 40,2%
Wastewater treatment by The Industrial Zone - CO2e +/- 61.1%
For fossil fuel combustion (stationary and mobile combustion), the uncertainties in CO2
EF are comparatively low since it depends on the fuels’ C content, which limits the
The uncertainty surrounding emission factors (EFs) for methane (CH4) and nitrous oxide (N2O) is considerable, primarily due to deficiencies in monitoring systems, measurement inaccuracies, and insufficient understanding of the emission-generating processes Stochastic variations in process conditions further contribute to the significant variability observed in the measured EFs for CH4.
Carbon footprint of the manufacturer’s products
Life cycle inventory analysis
Direct and significant indirect emissions have been calculated and presented in Section 3.1 After that, these emissions will be allocated to unit processes in manufacturing bolts
A number of emissions and removals required in ISO 14067:2018 for calculation of CFP have been determined from GHG Inventory, and these sources are reported as Table 3.6:
Table 3.6: Specific emissions and removals required in the carbon footprint of products
Emissions and removals Total quantity (tCO 2 e)
Lifecycle Impact Assessment
The manufacturing process is organized into unit processes, with inputs and outputs accounted for and excluded based on cut-off criteria as outlined in Table 2.9 In line with ISO 14067:2018, allocation to products is only performed when necessary, following the standard allocation rules of EN 15804:2012+A2:2019/AC:2021 This ensures that the total material and energy flows allocated to products equal the sum of inputs and outputs within each unit process A consistent allocation method is applied to equivalent inputs and outputs, adhering to ISO 14044:2006 standards, which prevents duplication or exclusion unless specific assumptions are made The allocation rules for the organization's products are implemented based on these principles.
Allocation based on physical relationships
Unless otherwise stated, allocations in this study will be based on the physical characteristics of the product (e.g., mass, volume)
Allocation based on economic value of the products
For other cases where physical allocation is not possible, allocation shall be based on the economic value of the products as they leave the unit process
The classification of bolt products includes those subjected to annealing and those that are not, as well as variations based on different plating processes In total, 12 types of bolts have been evaluated, and their carbon footprint is illustrated in Figure 3.6.
Figure 3.6: Carbon footprint of different types of bolts ( * 12,9: with Annealing
Bolts undergoing the annealing process exhibit a higher carbon footprint compared to those that do not Specifically, hot dip galvanized (HDG) bolts have the highest carbon footprint, measuring 4.236 tCO2e per ton To facilitate a meaningful comparison with other products, it is essential to adhere to the ISO 14067:2018 standards However, there is a lack of studies that adequately address the carbon footprint of bolts.
49 these requirements have been found at the time of making this thesis
The emissions that contribute to the carbon footprint of each product are presented in Figure 3.7
Figure 3.7: Share of specific emissions and removals in the carbon footprint of products in percentage
The carbon footprint of each product is primarily driven by emissions from raw materials and electricity usage, with steel purchased from suppliers being a significant contributor In the case of hot-dip galvanized (HDG) bolts, the highest carbon emissions stem from fossil carbon sources, including liquefied petroleum gas (LPG), as well as the zinc used for plating.
Sensitivity analysis of the CFP
Sensitivity analysis for Bolt HDG reveals that annealing contributes significantly to its carbon footprint The life cycle emissions of this bolt type are primarily driven by fossil carbon from LPG consumption, electricity usage, and the sourcing of raw materials.
Emission from LUC Emission from fossil carbonEmission from biogenic carbon Emission from Air TransportationEmission from Electricity use Emission from Raw materialsOther Sources
(Steels’ emission factor), and other sources (Zinc emission factor) Hence, a sensitivity analysis was conducted with a range of ±20% for these parameters The results are shown in Table 3.8:
Table 3.8: Results of the sensitivity analysis
Figure 3.8: Analysis of carbon footprint values based on changes in sensitivity factors
The thesis examines the limitations of organizational scope, highlighting that factors such as the electricity grid emission factor and LPG emission factor are beyond the manufacturer's control Additionally, it notes that any alterations in the consumption of steel and zinc, which are key inputs, would unrealistically impact the output of products.
The carbon footprint of HDG bolts is primarily influenced by the steel emission factor, which stands at 0.508, making it the most sensitive factor Following this, electricity use contributes a significant 0.277 to the overall footprint In contrast, variations in the zinc emission factor and LPG consumption result in minimal impacts on the carbon footprint, with changes of 20% leading to only 1.52% and 1.14% fluctuations in product emissions, respectively.
Recommendations for the studied company on establishing Emission
Based on the greenhouse gas (GHG) inventory and carbon footprint analysis conducted in this thesis, along with key category assessments and sensitivity analyses, several strategies are recommended for the manufacturer under study.
- Setting up a robust Emission Monitoring System according to ISO 14064-1:2018 with documented information for at least 10 years that can be verified by the independent third parties;
The manufacturer is required to comply with the GHG Inventory regulations and create a GHG emission reduction plan, adhering to the reporting guidelines established by the Government of Vietnam in Circular No.
38/2023/TT-BCT issued at December 27, 2023 on Methods for Measurement,
Report and Verification of Reduction in GHG Emissions and GHG Inventory
Development in Industry and Trade Sector (Vietnam, 2023) The manufacturer has built an effective EMS system under ISO, therefore, the workload on performing these requirements has been reduced greatly
The manufacturer has completed the quantification of its carbon footprint in accordance with ISO 14067:2018 Consequently, all data from the GHG Inventory has been assigned to the relevant unit processes for each product, in compliance with CBAM requirements Adjustments will be necessary in the selection of emission sources covered by CBAM.
To enhance calculation accuracy and reduce uncertainty, manufacturers should implement a robust Quality Management System in line with ISO 9001:2015 and an effective Environmental Management System according to ISO 14001:2015 Adhering to these standards ensures regular calibration of monitoring devices and establishes a comprehensive documentation system that defines clear processes and responsibilities for each department within the organization.
Conclusions
This master's thesis examines a Vietnamese steel manufacturer that is required to conduct a greenhouse gas (GHG) inventory and calculate the carbon footprint of its products This compliance is driven by regulations from the Government of Vietnam and the Carbon Border Adjustment Mechanism (CBAM), particularly as the company exports its products to the European Union (EU).
According to ISO 14064-1:2018 and ISO 14069:2013, emission sources have been identified, and relevant activity data and emission factors have been gathered to calculate emissions All units have been standardized to CO2e using GWP-100 values for each greenhouse gas The findings reveal that indirect emissions constitute 98% of the manufacturer's total emissions, which aligns with the manufacturer's operations involving finished steel processes from suppliers, rather than producing primary steel from iron ore, a process that significantly contributes to fossil fuel consumption, accounting for 71% of the indirect emissions.
Key emission sources for manufacturers include direct emissions from Liquified Petroleum Gas used in heat treatment and drying (1,385.13 tCO2e), burning methanol for heating (842.35 tCO2e), refrigerants (528.61 tCO2e), diesel oil for forklifts (319.04 tCO2e), domestic wastewater treatment (184.05 tCO2e), and cropland converted to settlements (168.60 tCO2e) Indirect emissions are primarily from main materials such as rolled coil steel, bar rod, and carton (113,848.12 tCO2e), electricity imported from the EVN grid (32,627.50 tCO2e), and the transport of main materials via road (10,451.80 tCO2e) To effectively reduce emissions, initiatives should target these significant sources.
The carbon footprint quantification was conducted in accordance with ISO 14067:2018, followed by a Life Cycle Assessment (LCA) across four stages to determine the carbon footprint values of 12 bolt types Notably, bolts undergoing the hot-dip galvanizing (HDG) plating process exhibited the highest carbon footprint at 4.24 tCO2e per ton The emissions breakdown reveals that raw materials account for 55.09%, electricity usage contributes 27.88%, and zinc (Zn) emissions represent 10.97%.
Fossil carbon emissions, accounting for 5.88%, are the primary contributors to the carbon footprint of bolts Consequently, a sensitivity analysis was conducted on each parameter associated with these emissions A survey was distributed to the manufacturer's clients to gather insights on their usage profiles of the bolts.
The sensitivity analysis indicates that the steel emission factor significantly influences the carbon footprint, with a sensitivity coefficient of 0.508, while electricity use follows with a coefficient of 0.277 Therefore, emission reduction strategies for the upcoming financial year or GHG reporting period should prioritize plans to mitigate emissions from these key sources.