Chemistry

Carbon Dioxide in the Atmosphere

• CO2 is emitted in the atmosphere in many ways– Naturally carbon cycle, volcanic outgassing, – Human activities burning fossil fuels

• CO2 needed for– sustaining life on Earth– controlling the Earth's climate by trapping heat in the

atmosphere– essential to photosynthesis in plants and other

photoautotrophs– a prominent greenhouse gas

Each year, CO2 Emission Increases…

http://en.wikipedia.org/wiki/File:Global_Carbon_Emissions.svg

• Annual fluctuation of about 3–9 ppmv which roughly follows the Northern Hemisphere's growing season

• 2009 average global CO2 concentration≈ 0.0387% 387 parts per million by volume (ppmv)

• Resultcarbon dioxide has gradually accumulated in the atmosphere & its concentration is 39% above pre-industrial levels (2009)

Rates & Increases

Greenhouse Gas Remediation Projects

• Objective Remove greenhouse gases from the atmosphere, and thus tackle the root cause of global warming

• Offer comprehensive solution• Will take many years• Overlap with carbon capture/ CO2removal and

carbon sequestation projects

Techniques include…

• Ocean nourishment– Eg. Iron fertilisation of the oceans

• Creating biochar (anaerobic charcoal) and burying it to create terra preta

• Bio-energy with carbon capture and storage• Carbon air capture to remove carbon dioxide

from ambient air

Carbon Dioxide Removal

• The removal of CO2 from ambient air by carbon dioxide scrubbing

• Regarded as greenhouse gas remediation, which is a branch of geoengineering

• Proposed methods include:– Planting artificial trees– Build “scrubbing towers” ≈ filter towers– Quicklime process calcium oxide

Advantage & Disadvantages

• Advantage– removes the need for CO2 piping to transport the

gas to underground storage sites– allows the use of renewable energy and optimal

storage sites• Disadvantage– Can’t capture at large, point source emitters (eg.

power plants), as it is likely to be more efficient and cheaper to capture and store carbon dioxide from more concentrated streams

Carbon Dioxide Scrubbing Lab

Objective:

To see if the carbon dioxide produced by the marble and hydrochloric acid solution will be absorbed by the potassium hydroxide solution by observing the change in pH level using the universal indicator.

Materials

• Marble• Spoon• Test tube• U-tube• 2 test tube corks with tube connected (that fits the test tube

and the U-tube)• 2 test tube clamps• 2 graduated cylinders• 50mL potassium hydroxide solution• 10 drops universal indicator• 10mL hydrochloric acid

Procedure1. Pour a ½ spoon full of marble into a test tube and hold it on a clamp.2. In a U-tube, pour in 50mL of the potassium hydroxide solution3. Add 10 drops of universal indicator into #2 and make sure the

indicator gets mixed in thoroughly and hold the U-tube on another clamp.

4. Take note of the colour if the potassium hydroxide solution and its pH level.

5. Plug the one of the corks that are connected by a tube with one opening of the U-tube.

6. Pour 10mL of hydrochloric acid into the test tube with the marble and quickly plug the other connected cork in this test tube.

7. Make close observations of the reactions that are made and the changes in colour of the potassium hydroxide solution.

Carbon Dioxide Scrubbing Lab Video

**Speed is fast-forwarded (150%)

Results

After mixing:Colour= yellowpH level≈ 6 (neutral)

In the beginning:Colour= bluepH level≈ 12 (alkali/basic)

http://teamstudent.com/2010/08/15/a-first-hand-investigation-to-prepare-and-test-a-natural-indicator/

Discussion for Chemistry Lab

Chemical Equation:

€

CO2 + 2KOH ⏐ → ⏐ K2CO3 +H2OBASIC NEUTRAL

€

CO2 +H2O ⏐ → ⏐ H2CO3

WEAK ACID

Reflection

• Positive– We contacted each other quite often and

exchanged a lot of ideas especially in the beginning– Each and every one of us did our individual work

that we had to complete• Negative– After the work day, the communication stopped for

a while as we were working on our individual parts– We didn’t reflect back on the sources that we used