What is the energy profile of the textile industry?

16 06 2009

carbon_footprint

If you’ve been following along you’ll know we haven’t even reached the point where we begin weaving – everything up till now dealt only with producing the raw materials (the fiber) and spinning into yarn!

So, the yarns are at the mill.  And that’s the kicker: we’ve been talking about how much energy it takes to produce the various fibers – and it varies dramatically – but there is no dramatic difference in the amount of energy needed to weave fibers into fabric depending on fiber type.[1] The processing is generally the same whether the fiber is nylon, cotton, hemp, wool or polyester:

  • thermal energy required per meter of cloth is 4,500-5,500 Kcal and
  • electrical energy required per meter of cloth is 0.45-0.55 kwh. [2]

This translates into huge quantities of fossil fuels  –  both to create energy directly needed to power the mills, produce heat and steam, and power air conditioners, as well as indirectly to create the many chemicals used in production.  In addition, the textile industry has one of the lowest efficiencies in energy utilization because it is largely antiquated.

So let’s go with the energy used to produce one KG of fabric (which is 92 MJ per KG as the New Zeland Merino Wool LCA study found).   Keeping  the energy needed for production as a  constant the synthetic fabrics still top the list:

Embodied Energy in production of various fibers + processing:
energy use in MJ per KG of fiber: energy use in MJ per KG of fabric TOTAL energy use in MJ per KG of fabric to produce fiber + weave into cloth
flax 10 92 102
Cotton, convt’l. 55 92 147
wool 63 92 155
Viscose 100 92 192
Polypropylene 115 92 207
Polyester 125 92 217
acrylic 175 92 267
Nylon 250 92 342

 

That means that it takes 3,886 MJ of energy to produce 25 yards of nylon fabric, which is  about enough to cover one average sofa.  That compares to 1,158 MJ if the fiber you used was flax (linen).  To put that into perspective, 1 gallon of gasoline equals 131 MJ of energy; driving a Lamborghini from New York to Washington D.C. uses approximately 2266 MJ of energy.(4)

Textile_total_energy_input

In addition to the energy requirements for textile production,  there is an additional dimension to consider during processing:  environmental pollution.  Conventional textile processing is highly polluting:

  • Up to 2000 chemicals are used in textile processing, many of them known to be harmful to human (and animal) health.   Some of these chemicals evaporate, some are dissolved in treatment water which is discharged to our environment, and some are residual in the fabric, to be brought into our homes (where, with use, tiny bits abrade and you ingest or otherwise breathe them in).  A whole list of the most commonly used chemicals in fabric production are linked to human health problems that vary from annoying to profound.  And new research is linking many diseases and disorders to exposure to chemicals.  Through the new science of environmental health science, we are learning that exposure to toxic chemicals (at levels once thought to have been safe) is increasing the  chronic disease burden for millions of us.  For more information about this disturbing concept,  check out the National Institute of Environmental Health Sciences, part of the National Institutes of Health.
  • The application of these chemicals uses lots  of water. In fact, the textile industry is the #1 industrial polluter of fresh water on the planet.[3] These wastewaters are discharged (largely untreated) into our groundwater with a high pH and temperature as well as chemical load.  I wrote about a documentary which catalogues the ravages brought on by water pollution and how it impacts those downstream, called (interestingly enough), DOWNSTREAM.

We are all downstream.


[1] 24thsession of the FAO Committee on Commodity Problems IGG on Hard Fibers of the United Nations

[2] “Improving profits with energy-efficiency enhancements”, December 2008,  Journal for Asia on Textile and Apparel,  http://textile.2456.com/eng/epub/n_details.asp?epubiid=4&id=3296

[3] Cooper, Peter, “Clearer Communication,” Ecotextile News, May 2007.

(4)  from Annika Carlsson-Kanyama and Mireille Faist, 2001, Stockholm University Dept of Systems Ecology, htp://organic.kysu.edu/EnergySmartFood(2009).pdf

Embodied Energy in production of various fibers + processing:
beach image energy use in MJ per KG of fiber: energy use in MJ per KG of fabric TOTAL energy use in MJ per KG of fabric to produce fiber + weave into cloth
flax 10 92 102
Cotton, convt’l. 55 92 147
wool 63 92 155
Viscose 100 92 192
Polypropylene 115 92 207
Polyester 125 92 217
acrylic 175 92 267
Nylon 250 92 342
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