Green chemistry part 3   carbon footprints
Upcoming SlideShare
Loading in...5
×

Like this? Share it with your network

Share
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
3,288
On Slideshare
3,288
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
29
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide
  • Boardworks AS Chemistry Green Chemistry
  • Boardworks AS Chemistry Green Chemistry Teacher notes The units of carbon footprint are left out of the table, so that you can discuss students’ ideas about this. Data on the slide are from the World Resources Institute and are for 2005 (http://www.wri.org/chart/per-capita-co2-emissions-current-and-projected [November 2008]).
  • Boardworks AS Chemistry Green Chemistry
  • Boardworks AS Chemistry Green Chemistry
  • Boardworks AS Chemistry Green Chemistry
  • Boardworks AS Chemistry Green Chemistry Photo credit: Lara Liesma Wolff Teacher notes Image shows the lighting for Radiohead’s ‘In Rainbows’ tour. All of the lighting was done using LEDs, which used less than a quarter of the power of a traditional lighting rig.
  • Boardworks AS Chemistry Green Chemistry Teacher notes There is more than one kind of biofuel. See the Boardworks GCSE Science: Chemistry ‘ Combustion and Alternative Fuels ’ presentation for more information about biofuels.
  • Boardworks AS Chemistry Green Chemistry Teacher notes The by-products of biofuel production, such as pressed seedcake, can be burnt in power stations instead of fossil fuels or used as animal feed. Planting biofuel crops leads to loss of habitat and deforestation in order to make space to plant them. This reduces biodiversity. See the Boardworks GCSE Science: Chemistry ‘ Combustion and Alternative Fuels ’ presentation for more information about biofuels.
  • Boardworks AS Chemistry Green Chemistry Photo credit: Courtesy of DOE/NREL - Ford motor company Teacher notes Hydrogen is generated for fuel by the electrolysis of water. This uses electricity, which must be generated somehow, and most often by the burning of fossil fuels. Although hydrogen is, therefore, cleaner than fossil fuels, it is not carbon neutral. Students should be able to reach this decision after some discussion.

Transcript

  • 1. 1 of 9 © Boardworks Ltd 2009
  • 2. 2 of 9 © Boardworks Ltd 2009 What are carbon footprints? Carbon footprint is a measure of the impact of a person’s activities on the environment, in terms of how much CO2 is produced by each activity. What do you think are the units of carbon footprint? Country Average carbon footprint USA Australia UK China India 20 17 10 3 1 (tonnes of CO2 per person per year)
  • 3. 3 of 9 © Boardworks Ltd 2009 Carbon footprints
  • 4. 4 of 9 © Boardworks Ltd 2009 Reducing your carbon footprint
  • 5. 5 of 9 © Boardworks Ltd 2009 What is carbon neutral? Carbon neutral describes any activity that produces no overall emissions of CO2. There are two ways of working towards carbon neutrality:  reducing carbon emissions  carbon offsetting. Carbon offsetting is the practice of balancing activities that emit CO2 with activities that absorb it; for example, planting trees that take in CO2 as they grow. Carbon offsetting is controversial because the act of planting trees in large numbers uses energy and emits CO2 even if the trees themselves absorb it.
  • 6. 6 of 9 © Boardworks Ltd 2009 What is carbon neutral? In 2003, the Rolling Stones went on the first carbon neutral tour. They calculated the amount of CO2 that would be produced by transporting the band, by fans travelling to the gigs and by energy use at the venues. Radiohead toured in the summer of 2008 using only reduction of emissions, not carbon offsetting. Do you think both of these methods are equally good? To make up for the CO2 produced, they organized the planting of two new forests in Scotland with trees that would absorb the same amount of CO2.
  • 7. 7 of 9 © Boardworks Ltd 2009 Are biofuels carbon neutral?
  • 8. 8 of 9 © Boardworks Ltd 2009 Advantages of biofuels
  • 9. 9 of 9 © Boardworks Ltd 2009 Is hydrogen carbon neutral? When hydrogen is burned as a fuel, the only product is water. Do you think hydrogen is a carbon neutral fuel? The hydrogen fuel is generated by the electrolysis of water. 2H2 + O2 → 2H2O Fuel cells that use this method of energy production can be incorporated into engines, as shown on the right.
  • 10. 9 of 9 © Boardworks Ltd 2009 Is hydrogen carbon neutral? When hydrogen is burned as a fuel, the only product is water. Do you think hydrogen is a carbon neutral fuel? The hydrogen fuel is generated by the electrolysis of water. 2H2 + O2 → 2H2O Fuel cells that use this method of energy production can be incorporated into engines, as shown on the right.