Chapter 11:Environmental Impact

Lecture 1: The Environmental Impact of Bio-based Composites

Learning Objectives

• Identify some environmental impacts of bio-based materials

• Discuss some trends in resource availability• Understand the potential advantages of

composite materials

Bio-based Materials have Several Potential Advantages

• Renewable• Abundant• Carbon neutral• Low processing energy• Biodegradable• Cost effective• Domestic supply

• Sustainable?

Increasing Wood Use - USA

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20100

50000

100000

150000

200000

250000

Woo

d pr

oduc

tion

(tho

usan

d to

ns)

Data from: J Howard. 2007. Research Paper FPL–RP–637

• Growing population uses more resources

• Wood use per person per day?– Equal to a ‘2 by 4’

about 5 feet long– About 3 times the

global average

Wood Use Over Time - USA

Source: J Howard. 2007. Research Paper FPL–RP–637

• Per person usage of wood has been decreasing– Increased efficiency– Substitution

• Increasing population means more wood use overall

Wood Use in USA

• USA is world’s largest consumer AND producer of wood products

http://fia.fs.fed.us/library/briefings-summaries-overviews/docs/ForestFactsMetric.pdf

Global Condition of Forests

• Deforestation is serious problem worldwide• About 0.18% loss per

year globally• Variable – US and

European forests are increasing.

• Rate of deforestation is decreasing

US Forest Inventory - US

• Forest inventory is increasing– Even as cutting

(‘removals’) increases

1953 1963 1977 1987 1997In

vent

ory

(m

illio

n c

ub

ic m

ete

rs)

0

5000

10000

15000

20000

25000

Gro

wth

and

rem

ova

ls (

mill

ion

cub

ic m

ete

rs p

er

year

)

0

200

400

600

800

1000

Inventory

Growth

Removals

http://fia.fs.fed.us/library/briefings-summaries-overviews/docs/ForestFactsMetric.pdf

Increasing Efficiency

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20100.5

0.6

0.7

0.8

0.9

1

Woo

d pr

oces

sing

prod

uctiv

ity

(ton

s pro

duce

d pe

r ton

of i

n-pu

t)

Data from: J Howard. 2007. Research Paper FPL–RP–637

– Very little waste– Wood use

efficiency has been steadily increasing in US

Composites Increase Efficiency

Data from: J Howard. 2007. Research Paper FPL–RP–637

– Raw material efficiency

• Waste wood/fiber• Higher utilization• Off species

Other Advantages of Composites

– Engineered– Randomize defects– Avoids size restrictions

• Can make big things from small pieces

– Reduced anisotropy

ww

w.colum

bia.edu/cu/gsapp/BT/BSI/DO

MES/dom

e.html

The Tacoma Dome is framed with wood composites

Wood/Bio-based Products Can Reduce Greenhouse Gasses

• Storing carbon in forest, building products, and landfills

• Using biomass (processing residues) for energy

• Substituting for (fossil) energy-intensive products such as concrete and steel

Green Building with Bio-based Composites

– Green building programs are developing

• E.g. LEED, Green Globes

• Can reward the use of greener materials

US energy use by sector, 2008. Buildings are responsible for a lot of energy consumption.

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w.eia.doe.gov/em

eu/aer/pdf/pages/sec2_4.pdf

Review

• Compare the environmental impact of bamboo and engineered wood flooring

• Do bio-based materials add to or reduce CO2 levels in the atmosphere (greenhouse effect)?

• Are bio-based materials sustainable?