LIFE CYCLE ASSESSMENT ON COTTON AND VISCOSE FIBRES FOR TEXTILE PRODUCTION Janka Dibdiakova, Volkmar Timmermann Norwegian Forest and Landscape Institute (NFLI) Ås, Norway COST FP1205 Innovative applications of regenerated wood cellulose fibres Bangor, United Kingdom 5.-6. March, 2014
OVERVIEW
A CRITICAL NEED The textile industry has always been challenged with balancing performance and cost. As resource availability and water scarcity concerns increase, the textile supply chain now has the additional challenge of environmental accountability. From fiber sourcing to end product, stakeholders and consumers alike are demanding method of measuring and reducing the environmental impact of textile products. Tools such as Life Cycle Inventories and Life Cycle Assessments can aid in environmental decision-making by identifying key impacts.
Cotton fibres LCA Viscose fibres
Cotton Fibres Cotton is a natural cellulose fibre. It is the most important of all natural fibres, accounting for half of all the fibres used by the world s textile industry. Cotton has many qualities that make it so useful very good strength, easy to handle. The most important cotton-growing countries are the China, India, USA, Pakistan and Australia.
Production and Consumption of Cotton Cotton Production 2011/12
Cotton Fibres Cotton needs a hot, sunny climate to grow, well-drained soil and a lot of rainfall/irrigation during the growing season. Cotton is sustainable, renewable, and biodegradable, making it a good choice as an environmentally-friendly fibre. However it is not very cheap - often blended with other fabrics such as polyester.
Viscose Fibres (man-made) Viscose materials are synthetic polymers made from natural resources. Viscose fibres are made to replace cotton fibres and to become self-sufficient with regard to textile material. Water and air pollution caused by toxic compounds. Viscose fibres are now primarily covering high-value applications - characteristic position in the world fibres market.
Area Needed for Fibre Production
Comparison of fibres
Without man-made fibres there would be neither enough agricultural areas for food production nor sufficient water resources for humankind!
Life Cycle Tools Key to appreciating the scope and findings of research is an understanding of the connection between two critical tools in life cycle evaluations: A Life Cycle Inventory (LCI) is a collection of data sets that quantify energy, water, raw material requirements, air emissions, waterborne effluents, solid wastes and other environmental releases that occur throughout the life cycle of a product, process or activity. A Life Cycle Assessment (LCA) is an objective process to evaluate the potential environmental burdens associated with the entire life cycle of a specific product, process or activity, and is generally based upon information contained in Life Cycle Inventories.
Life Cycle Assessment (LCA) A cradle-to-grave LCA study is the full Life Cycle Assessment including resource extraction ('cradle'), processing and production, assembly of a product, transportation to the consumer, use phase and disposal phase (end of life, 'grave'). A cradle-to-gate LCA study includes all steps from the extraction of raw materials and fuels, followed by all conversion steps until the product (in our case: staple fibres) is delivered at the factory gate for further processing. The use phase and disposal phase of the product are omitted in this case.
ISO Standards for LCA LCA has been standardized by the International Standardization Organization (ISO) in the ISO 14040 series, namely: ISO 14040: 2006 - Principles and framework ISO 14041: 2006 - Goal and Scope definition and inventory analysis ISO 14042: 2006 - Life Cycle Impact assessment ISO 14043: 2006 - Interpretation ISO 14044: 2006 - Requirements and guidelines
Four Steps of a LCA Study 1. Defining the goal and scope of the study 2. Making a model of the product life cycle with all the environmental inputs and outputs (Life cycle inventory) 3. Understanding the environmental relevance of all the inputs and outputs (Life cycle impact assessment) 4. The interpretation of the study
METHODOLOGY
1. Defining the goal and scope of the study The research questions addressed by this study were: 1. What are the environmental impacts of the production of cotton fibres from USA and China, and viscose fibres? 2. Which steps in the process chain contribute most to the overall environmental burden of cotton and viscose fibre production? 3. What are the advantages and disadvantages of cotton fibres from an environmental point of view compared to viscose fibres?
Requirements for Data Quality and Reporting Assumptions Coverage: time of data collection, geography, technology Ambitions Precision, completeness, representativity Scientific principles Consistency Reproducibility Documentation of data and sources Uncertainty, sensitivity in results
System Boundaries What is included in the analysis, and what is left out?
Functional Unit Concept of LCA is to compare on function provided. Need to define comparable systems! In this study impacts were calculated for a functional unit of 1 000 kg of fibres.
2. Making a model of the product life cycle with all environmental inputs and outputs (Life cycle inventory) Data collection The LCI consists of primary and secondary data (in the categories fiber production, textile manufacturing, transportation, garment creation, use, and end-of-life). Primary data are collected through partnerships with researchers, industry, and co-operators, are supplemented with literature. Secondary data are provided by the SimaPro 7.3.3 software using the database Ecoinvent 2.2 (e.g., energy production, raw and process materials, transport, and wastewater treatment). These data are used to account for regional differences for similar processes (e.g., cotton fibres production in USA and China). Data integrity is an essential element of an LCI s utility!
SimaPro and Ecoinvent SimaPro comes with the full Ecoinvent dataset covering 2500 processes (released in 2003). This database is the result of a very large effort by Swiss institutes.
Data Input (cradle-to-gate inventory) Cotton fibres US data: The inventory includes the processes of soil cultivation, sowing, weed control, fertilization, pest and pathogen control, irrigation, harvest and ginning. Machine infrastructure is included. Inputs of fertilizers, pesticides and seed as well as their transports to the farm are considered. The direct emissions on the field are also included. The system boundary is at the farm gate. Raw cotton is separated into cotton fibres and cottonseed. China data: The inventory includes the cultivation of cotton upon Chinese standards. Included steps are soil cultivation, pesticides fertilization (mineral fertilizer), harvest, loading for transport and extraction of the fibres in a gin plant. Viscose fibres (from trees to viscose fibres) This module includes the production of sulphate pulp with the TCF bleaching process - including transports to the pulp mill, wood handling, chemical pulping and bleaching, drying process, energy production on-site, recovery cycles of chemicals and internal waste water treatment. The inventory includes the transformation of sulphate pulp to spinnable viscose. Geography: Data are from an Austrian company having production sites in different countries, so the data can be taken as an global average.
3. Understanding the environmental relevance of all the inputs and outputs (Life cycle impact assessment) Environmental impact categories Impact category Unit (equivalents) Substances included (eq. factor) Climate change kg CO 2 eq CO 2 (1), N 2 O (298), CH 4 (25), etc. Ozone depletion kg CFC-11 eq CH 4, ethane, HC, etc. Human toxicity kg 1,4-DB eq Heavy metals, toxic compounds, etc. Photochemical oxidant formation kg NMVOC Non-methane volatile organic compounds Particulate matter formation kg PM 10 eq Ammonia, NOx, SO 2, particulates Ionising radiation kg U235 eq Radioactive isotopes Terrestrial acidification kg SO 2 eq SO 2, NOx, NH 4 Freshwater eutrophication kg P eq P, PO 4 Marine eutrophication kg N eq Ammonia, ammonium, nitrate, N, NOx, etc. Terrestrial ecotoxicity kg 1,4-DB eq Heavy metals, toxic compounds, etc. Freshwater ecotoxicity kg 1,4-DB eq Heavy metals, toxic compounds, etc. Marine ecotoxicity kg 1,4-DB eq Heavy metals, toxic compounds, etc. Water depletion m 3 Ground and surface water
RESULTS
4. The interpretation of the study SimaPro process network
Environmental Impact Categories
kg 1,4-DB eq Human Toxicity 400 350 300 250 200 150 100 50 0 Mercury Cadmium Phosphorus Phosphorus Arsenic Lead Arsenic, ion Vanadium Zinc Aldicarb Viscose fibres, at plant/glo U Cotton fibres, ginned, at farm/us U Cotton fibres, ginned, at farm/cn U
kg 1,4-DB eq Terrestrial Ecotoxicity 120 100 80 60 40 20 0 Cypermethrin Aldicarb Diuron Phosphorus Remaining substances Viscose fibres, at plant/glo U Cotton fibres, ginned, at farm/us U Cotton fibres, ginned, at farm/cn U
kg 1,4-DB eq Freshwater Ecotoxicity 250 200 150 100 50 0 Phosphorus Cypermethrin Aldicarb Nickel, ion Viscose fibres, at plant/glo U Cotton fibres, ginned, at farm/us U Cotton fibres, ginned, at farm/cn U
CONCLUSIONS
LCA can identify processes that have large impacts on the environment, thereby helping to improve production. While most often focused on, green house gas (GHG) emissions is not necessarily the most important environmental impact category in any study. From this study we can conclude that the use of pesticides in the US cotton fibres production should be reduced. Chinese cotton fibres production leads to 13 % higher GHG emissions than US cotton fibres production and consumes almost 5 times as much water. Viscose fibres production leads to 51 % higher GHG emissions than US cotton fibres production. Need to define comparable systems / processes! The better the quality of the input data, the better results you will get. In many cases this implies that you have to find data yourself and add them to the Ecoinvent database (because the existing data are either missing or incomplete).
THANK YOU FOR YOUR KIND ATTENTATION! Photo: Daniel Flø, Norwegian forest and landscape institute