Carbon Footprint Study of Bamboo Scrimber Products Based on Life Cycle Assessment (LCA)
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe presented work represents one of the proposed methods for carbon footprint analysis and LCA. There is no way to verify the accuracy of the data and information provided. The authors should provide greater detail regarding the source and, above all, how the data was obtained. It is pointless to provide data with such precision. Decimal data are presented to the nearest one, hundredths to the nearest tens, and so on. There is no analysis of measurement error and the reported numerical results. These ambiguities must be corrected.
Author Response
Comments：The presented work represents one of the proposed methods for carbon footprint analysis and LCA. There is no way to verify the accuracy of the data and information provided. The authors should provide greater detail regarding the source and, above all, how the data was obtained. It is pointless to provide data with such precision. Decimal data are presented to the nearest one, hundredths to the nearest tens, and so on. There is no analysis of measurement error and the reported numerical results. These ambiguities must be corrected.
Respond：Regarding energy data, consumption data such as electricity is primarily obtained through energy settlement documents provided by enterprises, as well as by checking the readings of workshop electricity meters, and tracing back to their annual energy audit reports. For outsourced heat and other services, it is obtained through communication with the enterprise's finance department, based on invoices and settlement data provided by suppliers.
In terms of raw material data, the core data comes from the company's purchase records (invoices, orders) and the actual inventory/requisition ledgers of warehouse management. At the same time, for the main raw materials, the on-site personnel also verified the feeding records of the production department to ensure the matching between data and production cycle.
For data involving internal records of the enterprise, all data are recorded by its production, equipment, and warehousing departments during daily operations. The research team completed the cross-checking and extraction of data through interviews with relevant department personnel and by reviewing the aforementioned original record vouchers and system reports.
In addition, some upstream data (such as raw material extraction and power production) still rely on background databases, but the core inventory data strive to be sourced from actual business operation records to ensure their traceability and accuracy.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe articles' aim is well stated and the topic is interesting.
I think that the article is well structured; however, methods can be nuclear in some cases, due to the high number and the format of equations used.
I want to highlight the use of a regional database (as CLCD) because the use of them are highly encouraged, however, I suggest that you make a comparation by using other data sources (such as Ecoinvent).
Moreover, I think that the authors could improve the discussion of the article, because there is a lack of suggestions for reducing the carbon footprint of the bamboo-based products assessed.
There are some grammar and spelling mistakes that can be reviewed.
Author Response
Comment：The articles' aim is well stated and the topic is interesting.
I think that the article is well structured; however, methods can be nuclear in some cases, due to the high number and the format of equations used.
I want to highlight the use of a regional database (as CLCD) because the use of them are highly encouraged, however, I suggest that you make a comparation by using other data sources (such as Ecoinvent).
Moreover, I think that the authors could improve the discussion of the article, because there is a lack of suggestions for reducing the carbon footprint of the bamboo-based products assessed.
Respond：Thank you for your review comments, Professor. Your insights have truly surprised us. It's evident that you are an expert with many years of deep exploration in this field. After completing the carbon footprint assessments for three products, we are currently comparing CLCD with other databases. This will be our new research report. We hope to continue receiving your review in the future.
Reviewer 3 Report
Comments and Suggestions for AuthorsThere are significant issues that the authors need to address:
- The abstract should include background/objective, specific, quantified results/findings, and implications.
- The authors should present a clear gap, objectives, and contribution.
- Illustrate adhesives clearly: type, solid content, loading, and any missing information.
- Give a short description of the production site.
- Authors should provide data on energy and material inputs, emission factors, and data sources.
- Also, add qualitative uncertainty and data quality evaluation.
- The study needs a quantitative sensitivity analysis.
- For limitations, include data quality and geographical generalizability.
- Rewrite the conclusion section.
- Check the table's quality, units, and projection information in the caption.
- Authors should check the grammar and sentence structure throughout the manuscript for improvements.
- Please check the references and add DOIs for missing references (if any). Ensure all the references in the reference list follow the required standard.
Author Response
Comment 1.The abstract should include background/objective, specific, quantified results/findings, and implications.
Respond1：Thank you for your review comments. The abstract has been revised.
The original text before modification is as follows.
‘Conducting carbon footprint studies on bamboo scrimber products based on Life Cycle Assessment (LCA) can quantitatively declare its environmental performance and further the cleaner-production improvement. This study established a life cycle model and inventory data set for bamboo scrimber flooring from "cradle to gate," accurately quantifying carbon emissions during raw material transportation and product production stages. Two types of bamboo scrimber flooring processes (deep carbon and shallow carbon). In addition, this study compared the carbon footprints of products processed using bamboo scrimber flooring and bamboo plywood template production methods. Results showed that the carbon emissions during the processing of 1m³ of deep carbon and shallow carbon bamboo scrimber flooring were 1845.99 kg CO2 e and 1570.85 kg CO2 e respectively. When coupling the carbon storage of raw material supply and product usage stages, the life-cycle carbon footprints for 1m³ of deep carbon and shallow carbon bamboo scrimber flooring were 962.23 kg CO2 e and 677.86 kg CO2 e, respectively. The carbon emissions and life cycle carbon footprint for the processing of bamboo plywood templates were 1435.55 kg CO2 e and 640.23 kg CO2 e, respectively. Analysis of different these processes and effects that found adhesives had the greatest impact on the carbon footprint. ’
The revised original text is as follows.
‘Understanding the carbon footprint of biomass products holds significant practical importance for energy conservation and emission reduction. Conducting carbon footprint studies on bamboo scrimber products based on Life Cycle Assessment (LCA) can quantitatively declare its environmental performance and further the cleaner-production improvement. This study established a model of life cycle and inventory data set for bamboo scrimber flooring from ‘cradle to gate’ that accurately quantifying carbon emissions during raw material transportation and product production stages. Two types of bamboo scrimber flooring processes include deep carbon and shallow carbon. In addition, this study compared the carbon footprints of products processed using bamboo scrimber flooring and bamboo plywood template production methods. Results showed that the carbon emissions during the processing of 1m³ of deep carbon and shallow carbon bamboo scrimber flooring were 1845.99 kg CO2-eq and 1570.85 kg CO2-eq respectively. When coupling the carbon storage of raw material supply and product usage stages that the life-cycle carbon footprints for 1m³ of deep carbon and shallow carbon bamboo scrimber flooring were 962.23 kg CO2-eq and 677.86 kg CO2-eq respectively. The carbon emissions and life cycle carbon footprint for the processing of bamboo plywood templates were 1435.55 kg CO2-eq and 640.23 kg CO2-eq, respectively. Due to analysis of different these processes and effects that found adhesives had the greatest impact on the carbon footprint. ’
Comment 2.The authors should present a clear gap, objectives, and contribution.
Respond2:Thank you for the expert's review. This part has been revised and submitted to the editorial department.
Comment 3.Illustrate adhesives clearly: type, solid content, loading, and any missing information.
Respond3:Thank you for the expert's review comments. In this study, the solid content of the adhesive used for the three bamboo products was 15%. Due to its consistency, this indicator was not important during the research process. Even if the solid content of the adhesive was reduced, it would not affect the research conclusion. In summary, we have decided to delete this data from the manuscript.
Comment 4.Give a short description of the production site.
Respond4:The production site for the product is primarily located in the panel manufacturers in Zhejiang Province, China. The production process involves a production line consisting of splitting, defibrating, drying, impregnating, secondary drying, laying, sawing, and other steps. The production flow is illustrated in the figure below.
Comment 5.Authors should provide data on energy and material inputs, emission factors, and data sources.
Respond5：Regarding energy data, consumption figures such as electricity are primarily obtained through energy settlement documents provided by enterprises, as well as by checking the readings of workshop electricity meters, and tracing back to their annual energy audit reports. For outsourced heat energy and the like, information is gathered through communication with the enterprise's finance department, based on invoices and settlement data provided by suppliers.
In terms of raw material data, the core data comes from the enterprise's purchase records (invoices, orders) and the actual inventory/requisition ledgers of warehouse management. At the same time, for the main raw materials, the on-site personnel also verify the feeding records of the production department to ensure the matching between data and production cycle.
For data involving internal records of the enterprise, all data are recorded by its production, equipment, and warehousing departments during daily operations. The research team completed the cross-checking and extraction of data through interviews with relevant department personnel and by reviewing the aforementioned original record vouchers and system reports.
In addition, some upstream data (such as raw material extraction and power production) still rely on background databases, but the core inventory data strive to be sourced from actual business operation records to ensure their traceability and accuracy.
Comment 6.Also, add qualitative uncertainty and data quality evaluation.
Respond6：Thank you for your review comments. We are very happy. Because this research is exactly what we are currently working on. We have added a comparison between CLCD and other databases in the new research report, as well as a detailed data quality assessment. We look forward to your continuous guidance in subsequent research reports.
Comment 7.The study needs a quantitative sensitivity analysis.
Respond7：Thank you for your review comments.This study established a model of life cycle and inventory data set for bamboo scrimber flooring from ‘cradle to gate’ that accurately quantifying carbon emissions during raw material transportation and product production stages. Two types of bamboo scrimber flooring processes include deep carbon and shallow carbon.The sensitivity analysis will be presented in the comparative data study.
Comment 8.For limitations, include data quality and geographical generalizability.
Respond8:Thank you for your professional and insightful comments. We will focus on these issues in our follow-up research.
Comment 9.Rewrite the conclusion section.
Respond9：Thank you for your review comments. The conclusion has been revised.
The original text before modification is as follows.
‘A carbon footprint evaluation framework based on LCA was constructed, including four aspects: goal and scope definition, inventory analysis, lifecycle modeling, and result interpretation. The functional units of this study were determined to be 1 m³ of deep carbon bamboo scrimber flooring, 1 m³ of shallow carbon bamboo scrimber flooring, and 1 m³ of bamboo plywood templates. The system boundary was "cradle-to-gate," including stages such as raw material acquisition and transportation, product production, and warehouse distribution. Considering the characteristics of artificial board products, the system boundary was extended to include both upstream and downstream stages, comprehensively considering the carbon storage of raw material supply and the products themselves. The main conclusions are as follows.
(1) The carbon footprint during the production stage of bamboo scrimber flooring products was quantified with high precision. The LCA impact assessment and result interpretation for the two types of artificial board products revealed that the carbon emissions during the production process of 1 m³ of deep carbon bamboo scrimber flooring and shallow carbon bamboo scrimber flooring were 1,845.99 kg CO2 e and 1,570.85 kg CO2 e, 1435.55 kg CO2 e respectively. Further sensitivity analysis revealed that adhesives had the greatest sensitivity in the product production stage inventory.
(2) The carbon emissions during the production stage of artificial board products were coupled with the carbon storage at the raw material supply stage and the carbon storage during the product use stage to integrate the lifecycle carbon footprint evaluation. The lifecycle carbon footprints of 1 m³ of deep carbon bamboo scrimber flooring and shallow carbon bamboo scrimber flooring were 962.23 kg CO2 e , 677.86 kg CO2 e and 640.23 kg CO2 e respectively. ’
The revised original text is as follows.
‘A carbon footprint evaluation framework based on LCA was constructed that including four aspects: goal and scope definition, inventory analysis, lifecycle modeling, and result interpretation. The functional units of this study were determined to be 1 m³ of deep carbon bamboo scrimber flooring that 1 m³ of shallow carbon bamboo scrimber flooring, and 1 m³ of bamboo plywood templates. The system boundary was 'cradle-to-gate' including stages such as raw material acquisition and transportation that product production and warehouse distribution. Considering the characteristics of artificial board products, the system boundary was extended to include both upstream and downstream stages. Comprehensively considering the carbon storage of raw material supply and the products themselves. The main conclusions are as follows.
(1) The carbon footprint during the production stage of bamboo scrimber flooring products was quantified with high precision. The LCA impact assessment and result interpretation for the two types of artificial board products revealed that the carbon emissions during the production process of 1 m³ of deep carbon bamboo scrimber flooring and shallow carbon bamboo scrimber flooring were 1,845.99 kg CO2-eq and 1,570.85 kg CO2-eq, 1435.55 kg CO2-eq respectively. Further sensitivity analysis revealed that adhesives had the greatest sensitivity in the product production stage inventory.
(2) Combine the carbon emissions during the production phase of wood-based panel products with the carbon storage during the raw material supply phase and the carbon storage during the product use phase, thereby achieving a comprehensive assessment of the carbon footprint across the entire life cycle. The lifecycle carbon footprints of 1 m³ of deep carbon bamboo scrimber flooring and shallow carbon bamboo scrimber flooring were 962.23 kg CO2-eq , 677.86 kg CO2-eq and 640.23 kg CO2-eq respectively. ’
Comment 10.Check the table's quality, units, and projection information in the caption.
Respond10：Thank you for the expert's review comments. The issues regarding the units of measurement in the text have been corrected.
Comment 11.Authors should check the grammar and sentence structure throughout the manuscript for improvements.
Respond11：Thank you for the expert's review comments.The full artical has been revised sentence by sentence.
Comment 12.Please check the references and add DOIs for missing references (if any). Ensure all the references in the reference list follow the required standard.
Respond12：Thank you for the expert's review comments.The full reference has been revised.
Reviewer 4 Report
Comments and Suggestions for AuthorsGeneral Assessment:
The manuscript addresses an important topic on the carbon footprint of bamboo scrimber products using LCA. The study is relevant to sustainable materials and environmental assessment; however, the paper in its current form suffers from significant language, clarity, and formatting issues that impair readability and the interpretation of results.
Major Concerns:
- Extensive English language problems (grammar, syntax, awkward expressions, incomplete sentences). A professional language edit is required.
- Abstract and Introduction require restructuring to improve clarity, coherence, and logical flow.
- Methodology section contains unclear explanations and formula formatting errors, making it difficult to follow the LCA procedures and variable definitions.
- Results and Discussion include unclear comparisons and inconsistent terminology (e.g., “deep carbon/shallow carbon”, “bamboo plywood template/formwork”).
- References contain multiple inconsistencies (incomplete citations, inconsistent formatting, placeholder authors).
- Figures and tables need improved formatting and higher resolution to be fully interpretable.
Minor Concerns:
- Units (kg CO2e vs. kg CO2 eq.) should be standardized.
- Equation numbering and variable definitions need correction.
- Clarify adhesive types and their carbon factors.
Overall:
The scientific topic is valuable, but the manuscript requires substantial revision to meet MDPI’s standards. I recommend that the authors undergo a major rewrite focusing on language clarity, structure, methodological transparency, and formatting before reconsideration.
Comments on the Quality of English LanguageGeneral Assessment:
The manuscript addresses an important topic on the carbon footprint of bamboo scrimber products using LCA. The study is relevant to sustainable materials and environmental assessment; however, the paper in its current form suffers from significant language, clarity, and formatting issues that impair readability and the interpretation of results.
Major Concerns:
- Extensive English language problems (grammar, syntax, awkward expressions, incomplete sentences). A professional language edit is required.
- Abstract and Introduction require restructuring to improve clarity, coherence, and logical flow.
- Methodology section contains unclear explanations and formula formatting errors, making it difficult to follow the LCA procedures and variable definitions.
- Results and Discussion include unclear comparisons and inconsistent terminology (e.g., “deep carbon/shallow carbon”, “bamboo plywood template/formwork”).
- References contain multiple inconsistencies (incomplete citations, inconsistent formatting, placeholder authors).
- Figures and tables need improved formatting and higher resolution to be fully interpretable.
Minor Concerns:
- Units (kg CO2e vs. kg CO2 eq.) should be standardized.
- Equation numbering and variable definitions need correction.
- Clarify adhesive types and their carbon factors.
Overall:
The scientific topic is valuable, but the manuscript requires substantial revision to meet MDPI’s standards. I recommend that the authors undergo a major rewrite focusing on language clarity, structure, methodological transparency, and formatting before reconsideration.
Author Response
The manuscript addresses an important topic on the carbon footprint of bamboo scrimber products using LCA. The study is relevant to sustainable materials and environmental assessment; however, the paper in its current form suffers from significant language, clarity, and formatting issues that impair readability and the interpretation of results.
Major Concerns:
1.Extensive English language problems (grammar, syntax, awkward expressions, incomplete sentences). A professional language edit is required.
Respond：Thank you for the expert's review comments.The full artical has been revised sentence by sentence.
2.Abstract and Introduction require restructuring to improve clarity, coherence, and logical flow.
Respond：Thank you for your review comments. The abstract and introduction has been revised.
The original text before modification is as follows.
‘Conducting carbon footprint studies on bamboo scrimber products based on Life Cycle Assessment (LCA) can quantitatively declare its environmental performance and further the cleaner-production improvement. This study established a life cycle model and inventory data set for bamboo scrimber flooring from "cradle to gate," accurately quantifying carbon emissions during raw material transportation and product production stages. Two types of bamboo scrimber flooring processes (deep carbon and shallow carbon). In addition, this study compared the carbon footprints of products processed using bamboo scrimber flooring and bamboo plywood template production methods. Results showed that the carbon emissions during the processing of 1m³ of deep carbon and shallow carbon bamboo scrimber flooring were 1845.99 kg CO2 e and 1570.85 kg CO2 e respectively. When coupling the carbon storage of raw material supply and product usage stages, the life-cycle carbon footprints for 1m³ of deep carbon and shallow carbon bamboo scrimber flooring were 962.23 kg CO2 e and 677.86 kg CO2 e, respectively. The carbon emissions and life cycle carbon footprint for the processing of bamboo plywood templates were 1435.55 kg CO2 e and 640.23 kg CO2 e, respectively. Analysis of different these processes and effects that found adhesives had the greatest impact on the carbon footprint. ’
The revised original text is as follows.
‘Understanding the carbon footprint of biomass products holds significant practical importance for energy conservation and emission reduction. Conducting carbon footprint studies on bamboo scrimber products based on Life Cycle Assessment (LCA) can quantitatively declare its environmental performance and further the cleaner-production improvement. This study established a model of life cycle and inventory data set for bamboo scrimber flooring from ‘cradle to gate’ that accurately quantifying carbon emissions during raw material transportation and product production stages. Two types of bamboo scrimber flooring processes include deep carbon and shallow carbon. In addition, this study compared the carbon footprints of products processed using bamboo scrimber flooring and bamboo plywood template production methods. Results showed that the carbon emissions during the processing of 1m³ of deep carbon and shallow carbon bamboo scrimber flooring were 1845.99 kg CO2-eq and 1570.85 kg CO2-eq respectively. When coupling the carbon storage of raw material supply and product usage stages that the life-cycle carbon footprints for 1m³ of deep carbon and shallow carbon bamboo scrimber flooring were 962.23 kg CO2-eq and 677.86 kg CO2-eq respectively. The carbon emissions and life cycle carbon footprint for the processing of bamboo plywood templates were 1435.55 kg CO2-eq and 640.23 kg CO2-eq, respectively. Due to analysis of different these processes and effects that found adhesives had the greatest impact on the carbon footprint. ’
3.Methodology section contains unclear explanations and formula formatting errors, making it difficult to follow the LCA procedures and variable definitions.
Respond：Thank you for your review comments.The formatting errors in the entire text have been corrected.
4.Results and Discussion include unclear comparisons and inconsistent terminology (e.g., “deep carbon/shallow carbon”, “bamboo plywood template/formwork”).
Respond：Thank you for your review comments. All inconsistencies in the full text have been replaced.
5.References contain multiple inconsistencies (incomplete citations, inconsistent formatting, placeholder authors).
Respond：Thank you for the expert's review comments.The full reference has been revised.
6.Figures and tables need improved formatting and higher resolution to be fully interpretable.
Respond：Thank you for your review comments. The charts have been replaced. In the following reading, you can click the zoom button. The images should be clearer.
Minor Concerns:
- Units (kg CO2e vs. kg CO2 eq.) should be standardized.
- Respond：Thank you for the expert's review comments. The non-standard parts in the text have been replaced.
- Equation numbering and variable definitions need correction.
- Respond：Thank you for the expert's review comments. The equation parts in the text have been replaced.
- Clarify adhesive types and their carbon factors.
- Respond：Thank you for the expert's review comments. In this study, the solid content of the adhesive used for the three bamboo products was 15%. Due to its consistency, this indicator was not important during the research process. Even if the solid content of the adhesive was reduced, it would not affect the research conclusion. In summary, we have decided to delete this data from the manuscript.
Reviewer 5 Report
Comments and Suggestions for AuthorsThe manuscript provides a detailed life cycle assessment of bamboo scrimber flooring and bamboo plywood templates, incorporating raw material production, processing emissions, and carbon storage. The topic is relevant given the increasing interest in low-carbon building materials, and the study offers useful inventory data for bamboo-based products in China. However, the current version suffers from methodological gaps, insufficient transparency in calculations, a lack of statistical robustness, and several interpretative claims that are not fully supported by quantitative evidence. Substantial revisions are required to improve scientific rigor, reproducibility, and clarity.
The following are suggestions for improvement:
- Please present all LCI and carbon-storage results in complete tables including mean values, standard deviations, number of replicates, and uncertainty ranges.
- Please provide the full list of emission factors, GWP values, and database sources used, specifying versions of CLCD and IPCC references.
- Please justify why the system boundary is described as “cradle-to-gate” while several upstream and downstream carbon-storage components are included, and clarify the methodological consistency of expanding boundaries.
- Please explain whether allocation procedures were used for shared processes (e.g., electricity, adhesives, multi-output steps) and how allocation choices affect results.
- Please provide detailed information on adhesive composition, upstream production processes, and emission-factor sources, as adhesive contributions dominate the carbon footprint.
- Please clarify how field biomass measurements (DBH, rhizome sampling, drying procedures) were converted into carbon-storage values and include uncertainty analysis for these estimations.
- Please justify the assumed 20-year product lifetime for scrimber flooring and 5-year lifetime for plywood and discuss sensitivity of results to lifetime variations.
- Please provide verification that the carbon content coefficient (0.5042 kg COâ‚‚e/kg) is appropriate for bamboo culm biomass and specify whether this reflects biogenic carbon or includes fossil carbon.
- Please add a flow diagram of the complete LCA model showing all processes, data sources, and computational steps to improve transparency.
- Please report whether the model includes transport of adhesives, electricity generation mix, or on-site process emissions such as resin curing or VOC release.
- Please clarify whether Monte-Carlo uncertainty analysis or sensitivity analysis was applied beyond inventory-contribution analysis.
- Please explain the rationale behind comparing scrimber flooring with plywood templates despite differences in function, density, and service life, and consider using functional equivalence or normalization.
- Please avoid mixing biogenic carbon storage and fossil COâ‚‚ emissions in the same balance without clear methodological justification and refer to ISO 14067 or EN 16485 recommendations.
- Please quantify the carbon-storage decay after end-of-life and provide clear assumptions for landfill vs incineration scenarios, including biogenic carbon release.
- Please strengthen the discussion section by linking the results to international literature on bamboo LCA, highlighting methodological similarities and differences.
Author Response
The following are suggestions for improvement:
1.Please present all LCI and carbon-storage results in complete tables including mean values, standard deviations, number of replicates, and uncertainty ranges.
Respond：Greeting, Professor. Thank you for your insightful comments.
The production process data in this study represents the general level of a specific manufacturing enterprise. The real-world process data utilizes enterprise production statistics and actual production process tracking data from January 1, 2021, to December 31, 2021. The background data utilizes data from the database over the past six years. The product lifecycle model in this study includes raw material acquisition, product production, and warehousing and distribution, meeting the definition of the basic system boundary for this study. The background databases used include the CLCD database and the Swiss Ecoinvent database. Both of these background databases encompass the mining, manufacturing, and transportation processes of major energy sources, basic raw materials, and chemicals, meeting the requirements for the completeness of the background database. All real-world data adopts a consistent statistical standard, which is based on the unit output of each unit process. The CLCD database established a unified core model during its development process and maintained detailed documentation records, ensuring the process and consistency of the data collection process. The data quality of this study is evaluated from four aspects: data accuracy, data representativeness, model completeness, and model consistency.
1.Deep carbon recombinant bamboo flooring
The detailed data for the production process of deep carbon reconstituted bamboo flooring is presented in Table 1.
Table 6 Production process list data of deep carbon reconstituted bamboo flooring
|
Type |
Project Name |
Quantity |
Unit |
|
Product output |
Deep carbon reconstituted bamboo flooring |
1 |
m3 |
|
Raw materials/materials |
Moso bamboo timber |
2335.52 |
kg |
|
Adhesive |
0.47 |
t |
|
|
Activated charcoal |
0.12 |
kg |
|
|
Energy |
Diesel |
3.7 |
kg |
|
Electricity |
348.41 |
kWh |
|
|
Natural water |
9.85 |
t |
|
|
Environmental emissions |
CO2 |
12.18 |
kg |
|
NOx |
0.75 |
kg |
|
|
SO2 |
0.38 |
kg |
|
|
Waste to be disposed |
Waste activated carbon |
0.12 |
kg |
|
Slag |
1.5 |
kg |
The transportation distance and mode of raw materials for the production of deep carbon reconstituted bamboo flooring are shown in Table 2. Based on the suppliers of raw materials and their locations, the transportation distance was measured and estimated using map software.
Table 2 Raw material transportation of deep carbon reconstituted bamboo flooring
|
Project Name |
Weight（kg） |
Starting point |
Destination |
Transportation distance（km） |
Transportation Type |
|
Adhesive |
470 |
Zhaoqing in Guangdong |
Enterprise |
934 |
Truck transportation |
|
Diesel |
3.7 |
Nanping in Fujian |
Enterprise |
472 |
Truck transportation |
|
Moso bamboo |
2335.52 |
Supplier |
Enterprise |
235 |
Truck transportation |
Note：The upstream data sources for transportation data all come from the CLCD database.
The production data for the raw materials used in the product manufacturing process (shown in Table 3 for details) are all sourced from the CLCD and Ecoinvent databases.
Table 3 Background data source of deep carbon reconstituted bamboo flooring
|
Project name |
Process |
Dataset name |
Data platform name |
|
Adhesive |
Deep carbon-reconstituted bamboo flooring |
phenolic resin |
Ecoinvent 3.8 |
|
Activated charcoal |
Deep carbon-reconstituted bamboo flooring |
Activated charcoal |
CLCD-China 0.9 |
|
Diesel |
Deep carbon-reconstituted bamboo flooring |
Diesel |
CLCD-China 0.9 |
|
Electricity |
Deep carbon-reconstituted bamboo flooring |
East China Power Grid |
CLCD-China 0.9 |
|
Natural water |
Deep carbon-reconstituted bamboo flooring |
Natural water |
CLCD-China 0.9 |
|
Electricity |
Bamboo bundle |
East China Power Grid |
CLCD-China 0.9 |
|
Steam |
Bamboo bundle |
2.5MPaSteam |
CLCD-China 0.9 |
|
Gasoline |
Bamboo bundle |
Gasoline |
CLCD-China 0.9 |
|
Natural water |
Bamboo bundle |
Natural water |
CLCD-China 0.9 |
|
Waste activated carbon |
Deep carbon-reconstituted bamboo flooring |
hazardous waste, for incineration |
Ecoinvent 3.8 |
|
Wastewater |
Bamboo bundle |
wastewater, unpolluted |
Ecoinvent 3.8 |
- Light carbon reconstituted bamboo flooring
The detailed data for the production process of light carbon-reconstituted bamboo flooring is presented in Table 4.
Table 4 Production process list data of shallow carbon reconstituted bamboo flooring
|
Type |
Project Name |
Quantity |
Unit |
|
Product output |
Light carbon recombinant bamboo flooring |
1 |
m3 |
|
Raw materials/materials |
Activated charcoal |
0.03 |
kg |
|
Adhesive |
0.42 |
t |
|
|
Moso bamboo timber |
2438.1 |
kg |
|
|
Energy |
Natural water |
9.72 |
t |
|
Electricity |
344.3 |
kWh |
|
|
Diesel |
2.86 |
kg |
|
|
Environmental emissions |
NOx |
0.99 |
kg |
|
SO2 |
0.57 |
kg |
|
|
Total particulate matter |
1.14 |
kg |
|
|
CO2 |
10.55 |
kg |
|
|
Waste to be disposed |
Waste activated carbon |
0.03 |
kg |
|
Product output |
Slag |
1.98 |
kg |
The transportation distance and mode of raw materials for the production of light carbon recombinant bamboo flooring are shown in Table 5. Based on the raw material suppliers and their locations, the transportation distance is measured and estimated using map software.
Table 5 Raw material transportation of shallow carbon reconstituted bamboo flooring
|
Project Name |
Weight（kg） |
Starting point |
Destination |
Transportation distance（km） |
Transportation Type |
|
Adhesive |
420 |
Zhaoqing in Guangdong |
Enterprise |
934 |
Truck transportation |
|
Diesel |
2.86 |
Nanping in Fujian |
Enterprise |
472 |
Truck transportation |
|
Moso bamboo |
2438.1 |
Supplier |
Enterprise |
235 |
Truck transportation |
Note：The upstream data sources for transportation data are all from the CLCD database.
The production data for the raw materials used in the production process of light carbon recombinant bamboo flooring is the same as that for deep carbon recombinant bamboo flooring, and both are sourced from the CLCD and Ecoinvent databases.
- Bamboo plywood formwork
The production process checklist data for bamboo plywood formwork is shown in Table 6.
Table 6 Production process list data of bamboo plywood formwork
|
Type |
Project Name |
Quantity |
Unit |
|
Product output |
Bamboo plywood formwork |
1 |
m3 |
|
Raw materials/materials |
Moso bamboo timber |
3142.46 |
kg |
|
Flooring |
26.6 |
kg |
|
|
Adhesive |
140 |
kg |
|
|
Energy |
Natural water |
44 |
kWh |
|
Electricity |
2.78 |
t |
|
|
Environmental emissions |
Total particulate matter |
0.14 |
kg |
|
CH4 |
0.02 |
kg |
|
|
SO2 |
0.06 |
kg |
|
|
NOx |
0.19 |
kg |
The transportation distance and mode of raw materials for product production are shown in Table 7. Based on the raw material suppliers and their locations, the transportation distance is measured and estimated using map software.
Table 7 Raw material transportation of bamboo plywood formwork
|
Project Name |
Weight（kg） |
Starting point |
Destination |
Transportation distance（km） |
Transportation Type |
|
Moso bamboo |
620 |
Supplier |
Enterprise |
268 |
Truck transportation |
|
Adhesive |
140 |
Zhaoqing in Guangdong |
Enterprise |
957 |
Truck transportation |
Note：The upstream data sources for transportation data are all from the CLCD database.
The production data for the raw materials used in the product manufacturing process (see Table 8 for details) are all sourced from the CLCD and Ecoinvent databases.
Table 8 Background data source of bamboo plywood formwork
|
Project name |
Process |
Dataset name |
Data platform name |
|
Moso bamboo |
Bamboo plywood formwork |
flattened bamboo |
Ecoinvent 3.8 |
|
Adhesive |
Bamboo plywood formwork |
phenolic resin |
Ecoinvent 3.8 |
|
Natural water |
Bamboo plywood formwork |
Natural water |
CLCD-China 0.9 |
|
Electricity |
Bamboo plywood formwork |
China Southern Power Grid |
CLCD-China 0.9 |
4.Wood plywood formwork
The production process checklist data for wood plywood formwork is shown in Table 9.
Table 9 Production process list data of plywood formwork
|
Type |
Project Name |
Quantity |
Unit |
|
Product output |
Wood plywood formwork |
1 |
m3 |
|
Raw materials/materials |
Timber |
1653.26 |
kg |
|
Adhesive |
66.67 |
kg |
|
|
Energy |
Electricity |
34 |
kWh |
|
Natural water |
0.35 |
t |
|
|
Packaging |
Packing bag |
0.06 |
kg |
|
Environmental emissions |
SO2 |
0.02 |
kg |
|
NOx |
0.05 |
kg |
The transportation distance and mode of raw materials for product production are shown in Table 10. Based on the raw material suppliers and their locations, the transportation distance is measured and estimated using map software.
Table 10 Raw material transportation of plywood formwork
|
Project Name |
Weight（kg） |
Starting point |
Destination |
Transportation distance（km） |
Transportation Type |
|
Packaging bag |
0.06 |
Anqing in Anhui |
Enterprise |
600 |
Truck transportation |
|
Timber |
860 |
Supplier |
Enterprise |
375 |
Truck transportation |
|
Adhesive |
66.67 |
Zhaoqing in Guangdong |
Enterprise |
948 |
Truck transportation |
Note：The upstream data sources for transportation data are all from the CLCD database.
The production data for the raw materials used in the product manufacturing process (as detailed in Table 11) are all sourced from the CLCD and Ecoinvent databases.
Table 11 Background data source of plywood formwork
|
Project name |
Process |
Dataset name |
Data platform name |
|
Timber |
Wood plywood formwork |
pine wood(40% water content) |
ELCD 3.0 |
|
Adhesive |
Wood plywood formwork |
melamine urea formaldehyde adhesive |
Ecoinvent 3.8 |
|
Electricity |
Wood plywood formwork |
East China Power Grid |
CLCD-China 0.9 |
|
Natural water |
Wood plywood formwork |
Natural water |
CLCD-China 0.9 |
|
Packaging bag |
Wood plywood formwork |
Low-density polyethylene - LDPE |
CLCD-China 0.9 |
|
Product transportation |
Wood plywood formwork |
Heavy-duty diesel semi-trailer transportation (load capacity 24t) |
CLCD-China 0.9 |
2.Please provide the full list of emission factors, GWP values, and database sources used, specifying versions of CLCD and IPCC references.
Respond：Thank you for the professor's insightful comments. In this study, the background database for adhesives, waste activated carbon, and wastewater is Ecoinvent 3.8, while the background databases for activated carbon, diesel, electricity, tap water, steam, gasoline, etc. are CLCD-China 0.9.
3.Please justify why the system boundary is described as “cradle-to-gate” while several upstream and downstream carbon-storage components are included, and clarify the methodological consistency of expanding boundaries.
Respond: The system boundaries considered in this study include two subsystem boundaries, namely the basic system boundary and the extended system boundary. The basic system boundary is "from cradle to gate", but considering that only by integrating dynamic analysis of forest carbon sink dynamics, carbon emissions during the production phase of products, and substitution emission reduction effects during the product use phase as a whole can the net emission reduction effects of forest management and wood forest products be relatively accurately calculated, this paper has appropriately extended the system boundaries (this part also refers to the literature "Yang Hongqiang, Yu Zhihan. Global Wood Forest Product Carbon Science Research Trends and Future Key Issues [J]. Journal of Nanjing Forestry University (Natural Science Edition), 2021, 45(4): 219-228.").
4.Please explain whether allocation procedures were used for shared processes (e.g., electricity, adhesives, multi-output steps) and how allocation choices affect results.
Respond：Thank you for the professor's insightful comments. In conducting the inventory analysis, we focus on individual production processes by calculating the consumption of various resources and energy, as well as environmental emissions. Therefore, shared processes are not involved in this study.
5.Please provide detailed information on adhesive composition, upstream production processes, and emission-factor sources, as adhesive contributions dominate the carbon footprint.
Respond：Thank you for the professor's comments. These data are sourced from Ecoinvent 3.8.
6.Please clarify how field biomass measurements (DBH, rhizome sampling, drying procedures) were converted into carbon-storage values and include uncertainty analysis for these estimations.
Respond：Thank you for the professor's comments. The carbon content of moso bamboo is sourced from "Assessment of Biomass and Carbon Storage of Forest Vegetation in China" (2010) and "The Second Monitoring Report on Land Use, Land-Use Change, and Forestry Carbon Sink Measurement in Zhejiang Province" (2016), with a reference value of 0.5042 kg CO₂e/kg. The carbon content of masson pine is sourced from a reference value of 0.5271 kg CO₂e/kg, and carbon storage is calculated by multiplying biomass with carbon content.
7.Please justify the assumed 20-year product lifetime for scrimber flooring and 5-year lifetime for plywood and discuss sensitivity of results to lifetime variations.
Respond：Thank you, Professor, for your insightful comments. The service lives of 20 years and 5 years were determined through communication with the manufacturing enterprise, representing the expected service life of their designed products, and were used as the basis for this study. As the design service life increases, according to PAS2050 and "", the carbon storage benefits will increase during the 100-year evaluation period.
8.Please provide verification that the carbon content coefficient (0.5042 kg COâ‚‚e/kg) is appropriate for bamboo culm biomass and specify whether this reflects biogenic carbon or includes fossil carbon.
Respond: We are deeply grateful for receiving your comments.The carbon content rate of moso bamboo is sourced from "Assessment of Biomass and Carbon Storage of Forest Vegetation in China" (2010), with a reference value of 0.5042 kg COâ‚‚e/kg. Carbon storage is calculated by multiplying biomass with carbon content rate, which is biological carbon. Additionally, the literature "Zhou Guomo. Research on Carbon Storage, Fixation, Allocation, and Distribution in Moso Bamboo Forest Ecosystems [D]. Zhejiang University, 2006" is referenced ”
9.Please add a flow diagram of the complete LCA model showing all processes, data sources, and computational steps to improve transparency.
Respond: We are deeply grateful for receiving your comments. Your feedback holds significant importance for our research endeavors.
In this study, the carbon footprint of producing 1m³ of deep carbon-reconstituted bamboo flooring, 1m³ of shallow carbon-reconstituted bamboo flooring, 1m³ of bamboo plywood formwork, and 1m³ of wood plywood formwork was calculated using the eFootprint system based on inventory data. The schematic diagram of the model is as follows.
Fig1 Schematic for deep carbon reconstituted bamboo flooring lifecycle model
Fig.2 Schematic for shallow carbon reconstituted bamboo flooring lifecycle model
Fig.3 Schematic for bamboo plywood formwork lifecycle model
Fig.4 Schematic for plywood formwork lifecycle model
10.Please report whether the model includes transport of adhesives, electricity generation mix, or on-site process emissions such as resin curing or VOC release.
Respond: Thank you for the professor's comments. Please report whether the model includes transportation of adhesives, power generation combinations, or on-site process emissions such as resin curing or VOC emissions. The model includes the transportation process of adhesives from their production sites to the manufacturing plant, as well as the electricity consumption for adhesive production, with data sourced from the background database Ecoinvent 3.8. The current model boundary does not include direct process emissions generated by resin curing (chemical crosslinking) reactions, nor does it include emissions from volatile organic compound (VOC) releases. Our system boundary setting mainly covers material and energy inputs from "cradle to gate", with on-site direct chemical reaction emissions considered as a secondary component and excluded.
11.Please clarify whether Monte-Carlo uncertainty analysis or sensitivity analysis was applied beyond inventory-contribution analysis.
Respond: Thank you for the professor's comments. In this study, we primarily utilized contribution analysis to identify the key components of the carbon footprint. Due to limitations in the source of the original data, we did not conduct a formal Monte Carlo uncertainty analysis or sensitivity analysis on the overall model. In future research, we will incorporate uncertainty analysis based on improvements in data availability.
12.Please explain the rationale behind comparing scrimber flooring with plywood templates despite differences in function, density, and service life, and consider using functional equivalence or normalization.
Respond: Thank you for the professor's comments.This involves the selection of research subjects in this study. Among them, plywood products account for 62.7% of the total consumption of wood-based panel products, making them the largest category of wood-based panel consumption in China. Reconstituted materials are the transformation and upgrading products of China's wood-based panel industry. Choosing these two types of materials is typical and representative. This study is not simply a comparison between plywood templates and reconstituted bamboo flooring, but involves the following dimensions: plywood templates, with the same usage scenario, compare wood and bamboo materials; in reconstituted bamboo flooring, with the same usage scenario, compare deep carbon and light carbon processes. When comparing reconstituted bamboo flooring and wood plywood templates, the functional unit is defined as "1m3" to ensure comparability.
13.Please avoid mixing biogenic carbon storage and fossil COâ‚‚ emissions in the same balance without clear methodological justification and refer to ISO 14067 or EN 16485 recommendations.
Respond: Thank you for the professor's comments. This study comprises two parts: the basic system boundary and the extended system boundary. It conducts an exploratory study on the integrated assessment of carbon emission reduction effects after forest harvesting, referencing the innovative coupling of carbon storage in the raw material supply chain and the use phase of PAS2050.
14.Please quantify the carbon-storage decay after end-of-life and provide clear assumptions for landfill vs incineration scenarios, including biogenic carbon release.
Respond: Thank you for the professor's comments. The system boundary of this study is "from cradle to gate", and it does not explore the scenario of disposal (landfill, incineration) after use. Further research will be conducted to explore the "from cradle to grave" system boundary.
15.Please strengthen the discussion section by linking the results to international literature on bamboo LCA, highlighting methodological similarities and differences.
Respond: Thank you for the professor's comments.
Adhesives are used as the main raw material input, with a carbon footprint of 1321.98 kgCO2e (accounting for 84.16% of the product's life cycle carbon footprint). Due to data availability limitations, this study did not investigate the production process, and there may be some deviations between the calculated results and the actual environmental performance of the supply chain. Previous studies on the carbon footprint of recombinant bamboo flooring have shown that the carbon emissions during the processing of 1 m3 of recombinant bamboo flooring are 143.5591 kg CO2e, which is much lower than the data obtained in this study. There are two main reasons for this: external energy consumption such as moso bamboo planting, management, business activities, and power, water, and fertilizer also generates carbon emissions, which were not considered in previous studies; in addition, previous studies only considered the carbon emissions generated by adhesives during the use phase, without considering the carbon emissions from the upstream production process. Unit resin impregnation is a core step in the high-quality preparation of recombinant materials [10]. Currently, the commonly used discontinuous batch impregnation can only ensure the uniformity of adhesive impregnation by reducing the moisture content of the recombinant units and extending the impregnation time, resulting in increased adhesive application and energy consumption during the preparation process. Optimizing the impregnation process by considering factors such as bamboo bundle moisture content, cross-sectional size, adhesive solid content, and impregnation time, or adopting continuous roller press impregnation technology can improve production efficiency and reduce energy consumption.
Adhesives, as the main raw material input, have a carbon footprint of 175.60 kgCO2e (accounting for 71.54% of the product's life cycle carbon footprint). Considering that the upstream production process of adhesives was not investigated, there may be some deviations in the calculation results from the actual environmental performance of the supply chain. In this study, using moso bamboo as the raw material, the carbon footprint of recombinant bamboo flooring is higher than that of bamboo plywood formwork. In the gluing process, the carbon footprint of plywood formwork made from different raw materials is lower than that of bamboo plywood formwork. Through inventory sensitivity analysis, it can be found that the inventory sensitivity of adhesives is relatively high. The carbon footprint contributions of adhesives in the production processes of deep carbon recombinant bamboo flooring, shallow carbon recombinant bamboo flooring, bamboo plywood formwork, and wood plywood formwork are 88.18%, 84.16%, 78.32%, and 71.54%, respectively. Combined with inventory analysis, it can be seen that the weight of adhesives consumed in the production of 1 m3 of deep carbon recombinant bamboo flooring, shallow carbon recombinant bamboo flooring, bamboo plywood formwork, and wood plywood formwork is 470 kg, 420 kg, 140 kg, and 66.67 kg, respectively. The analysis of the differences in carbon footprint during the production processes of various products mainly indicates that high-emission wood-based panel products use more adhesives during production. It is subsequently recommended to procure upstream raw materials with lower carbon emissions or alternative clean energy sources to reduce carbon emissions during the production process.
There are relatively few studies on the life cycle assessment (LCA) of plywood, with the majority of existing research focusing on the United States and few reports from other countries [10]. Wilson et al. [4] investigated eight representative plywood enterprises in the southeastern region of the United States and found that the environmental load during the production process was much greater than that during the operational stage. The carbon footprint for producing 1 cubic meter of plywood was 698 kg CO2e. The carbon footprint for producing 1 cubic meter of plywood in the Pacific Northwest region of the United States was lower than that in the southeastern region, at 674 kg CO2e, but both were higher than the carbon footprint of the plywood template studied in this research (245.44 kgCO2e). The reason for this may be attributed to the use of SimaPro software and the basic database of the country.
Comparative studies have found that bamboo plywood formwork has a significantly lower environmental impact than steel formwork with the same functionality, especially in terms of carbon footprint, primary energy consumption, and water resource consumption, where steel formwork is about 10 times worse than bamboo plywood formwork. Some studies have shown that the substitution emission reduction effect is on average more than one time the carbon content of the product itself, and can even be as high as 2 to 10 times when used in construction, which is consistent with the results of this study. The substitution emission reduction effect can be linked to the increase in carbon storage of wood forest products [30,142]. However, it should also be noted that most studies tend to be limited to energy substitution or substitution of certain product types, and there are relatively few forest management studies that incorporate multiple energy and product substitutions throughout the entire life cycle while also considering post-harvest carbon storage.
Author Response File: 
Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsDear Authors, how can I convince you that presenting results with such precision is pointless—1.845.99 kg CO2-eq! These results change hourly! I still don't see any indication of the measurement error limits. If you specify the error limits, you'll get a result of 1.1850 +/- 10..50...500. This isn't pure mathematics derived from statistics or calculated with some spreadsheet program.
Author Response
Comment: Dear Authors, how can I convince you that presenting results with such precision is pointless—1.845.99 kg CO2-eq! These results change hourly! I still don't see any indication of the measurement error limits. If you specify the error limits, you'll get a result of 1.1850 +/- 10..50...500. This isn't pure mathematics derived from statistics or calculated with some spreadsheet program.
Respond：
The suggestions provided by experts are professional and necessary. In this study, we utilize Taylor series analysis to calculate uncertainty, which primarily encompasses the uncertainty assessment of inventory data and background databases. Ultimately, we obtain the uncertainty of the LCA results and the fluctuation range within a 95% confidence interval.
|
Product |
Result of LCA（kg CO2-eq） |
Uncertainty（%） |
95% confidence interval fluctuation range（kg CO2-eq） |
|
Deep carbon-reconstituted bamboo flooring |
1845.99 |
10.25 |
（1656.78，2035.21） |
|
Light carbon recombinant bamboo flooring |
1570.85 |
10.33 |
（1408.58,1733.12） |
|
Bamboo plywood |
1435.55 |
11.08 |
（1276.49，1594.61） |
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors conducted the suggestions, so now it is ok for publication. Methods were specified, the use of regional databases were clarified, and the discussion were enhanced.
Author Response
Comment：The authors conducted the suggestions, so now it is ok for publication. Methods were specified, the use of regional databases were clarified, and the discussion were enhanced.
Respond：Thank you very much.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors considered my commnets.
Author Response
Comment:The authors considered my commnets.
Respond:Thank you very much.
Reviewer 5 Report
Comments and Suggestions for AuthorsThe authors have satisfactorily addressed the reviewers’ comments and improved the clarity and methodological consistency of the manuscript. The remaining limitations are clearly acknowledged and do not affect the validity of the results or conclusions. The manuscript is suitable for publication, and I recommend acceptance in its current form.
Author Response
Comment:The authors have satisfactorily addressed the reviewers’ comments and improved the clarity and methodological consistency of the manuscript. The remaining limitations are clearly acknowledged and do not affect the validity of the results or conclusions. The manuscript is suitable for publication, and I recommend acceptance in its current form.
Respond:Thank you very much.
