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Question and Answers
#1
Part #1

Question:

What is Carbon Dioxide?

Answer:

In answering the question.It will be shown that CO2 is a very important molecule for Industrial and Commercial use.That it is part of the Photosynthesis process that green plants use to make sugars,for the purpose of cellular growth.Which in turn feeds the world with its grains,fruit,leaves and roots that it produces.

In reading this Answer report.Consider this question,

Why does the Environmental Protection Agency (EPA) call CO2 a "pollutant"?

CO2 is a chemical compound composed of one atom of Carbon and two atoms of Oxygen,that is much heavier than air by molecular weight.It is a colorless, odorless gas (meaning you are not seeing or smelling them coming out of a smoke stack).It is water soluble (meaning it can be absorbed by water),producing weak carbonic acid.Some of the CO2 molecules can be absorbed by rain in the air.

Here is a simple chart showing decreasing solubility of CO2:

[Image: 174solublegas.gif]

Quote:Solubility of Gases vs. Temperature:

The variation of solubility for a gas with temperature can be determined by examining the graphic on the left.

As the temperature increases, the solubility of a gas decrease as shown by the downward trend in the graph .

More gas is present in a solution with a lower temperature compared to a solution with a higher temperature.

The reason for this gas solubility relationship with temperature is very similar to the reason that vapor pressure increases with temperature. Increased temperature causes an increase in kinetic energy. The higher kinetic energy causes more motion in molecules which break intermolecular bonds and escape from solution.

This gas solubility relationship can be remembered if you think about what happens to a "soda pop" as it stands around for awhile at room temperature. The taste is very "flat" since more of the "tangy" carbon dioxide bubbles have escaped. Boiled water also tastes "flat" because all of the oxygen gas has been removed by heating.

SOURCE

CO2 gasses out from the warm equatorial ocean waters,while CO2 enters cold polar waters.

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It is a trace gas in the current atmosphere at 390 parts per million (PPM) or .039% of the atmosphere by volume.This is historically a rare low point in geological history.Normally is it in excess of 1000 ppm in the atmosphere.

Here is a chart showing the varied CO2 concentrations in the atmosphere in last 600 million years:

[Image: image277.gif]

It is apparent that we are living in a time of CO2 impoverishment level in the atmosphere.At the end of the last ice age,it was barely above sustaining level in the atmosphere for plants to live with.This was around the 180-200 ppm level.

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CO2 can absorb in a limited range of Infrared radiation (IR) in three small bands of frequencies.They are 2.7, 4.3,14.99 microns.Meaning they absorb only a small portion of the outgoing IR. Most of the remaining outgoing IR are absorbed by Water Vapor and a few trace IR absorbing gases.Some of the IR just zooms right into outer space unabsorbed.

Here is a chart showing that the main CO2 band is mostly OUTSIDE the PEAK IR outflow section:

[Image: Atmospheric_Transmission.png]

The two smaller CO2 absorption bands absorb very little outgoing IR,since it is in the area where there are very little energy available to absorb.That is shown by the nearly flat lines.

Shown in yellow for Carbon Dioxide (CO2) in this chart below.There it shows that there are OVERLAPPING absorption zones between the main CO2 band (the biggest yellow hill) AND Water Vapor.

[Image: CO2_infrared_sorption_Tom.jpg]

CO2 does most of its Infrared absorption in just one band,the 14.99 microns area.While it strongly absorbs in that band.It is not doing so in the most energetic part of the IR outflow.Thus some of the energy is not being absorbed.There is a section in the IR window where outgoing IR can leave with little absorption taking place.

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Many decades of published peer reviewed science research have revealed that CO2 does not stay floating around in the atmosphere for very long.They have known short residence times since the 1950's.Here are a sample of published papers by list showing them:

They are published "peer reviewed" science papers that appear in major science journals.Such as Nature and Science.

Revelle & Suess [1957] 7 years
Broecker [1963], recalc. by Broecker & Peng [1974] 8 years
Keeling [1973b] 7 years
Broecker & Peng [1974] 8 years
Segalstad (1992) 5.4 years

The CO2 residence times in the atmosphere as shown in the above sample list.Came from this SOURCE.

They range from 2 years to 25 years.But most of the results are around 5-7 years.

Quote:The atmospheric residence time (i.e. lifetime; turnover time) of CO2 has been quantified based on measurements of natural radiocarbon (carbon-14) levels in the atmosphere and the ocean surface; the changes in those levels caused by anthropogenic effects, like "bomb carbon-14" added to the atmosphere by nuclear explosions; and the "Suess Effect" caused by the addition of old carbon-14-free CO2 from combustion of fossil fuels; and the application of gas exchange theory to rates determined for the inert radioactive gas radon-222. The results from these measurements are shown in Table 2, mainly based on the compilation by Sundquist (1985), in addition to the solubility data of Murray (1992), and the carbon-13/carbon-12 mass-balance calculation of Segalstad (1992). Both of the last two recent methods happened to give a lifetime of 5.4 years based on completely different methods.

SOURCE

This means that CO2 can not accumulate in the atmosphere.Not when some of it can be rained out,or absorbed by plants,or by chemical reactions.
#2
Part #2

Industrial and Commercial uses of CO2

CO2 are used in a variety of ways such as:

Fire extinguishers
Refrigerant
liquefaction or solidification of gases
Manufacture of fertilizer
Baking
Medicine
Aerated drinks
Commercial chemicals
Food storage
Setting of lime mortar
Entertainment industry

Example:

Quote:Manufacture of aerated drinks

Carbon dioxide is extensively used in aerated drinks. Increasing the pressure increases the solubility of the gas. The fizz in the drink is due to carbon dioxide being liberated when the pressure is reduced.

7UP,Coke,Pepsi are among such aerated drinks.

SOURCE


Rubber and Plastics Industry
Environmental Uses
Manufacturing and Construction
Metals Industry

Example:

Quote:Food and Beverages Uses for Carbon Dioxide:

Liquid or solid carbon dioxide is used for quick freezing, surface freezing, chilling and refrigeration in the transport of foods. In cryogenic tunnel and spiral freezers, high pressure liquid CO2 is injected through nozzles that convert it to a mixture of CO2 gas and dry ice "snow" that covers the surface of the food product. As it sublimates (goes directly from solid to gas states) refrigeration is transferred to the product.

Carbon dioxide gas is used to carbonate soft drinks, beers and wine and to prevent fungal and bacterial growth.

Liquid carbon dioxide is a good solvent for many organic compounds. It is used to de-caffeinate coffee.

It is used as an inert “blanket”, as a product-dispensing propellant and an extraction agent. It can also be used to displace air during canning.

Supercritical CO2 extraction coupled with a fractional separation technique is used by producers of flavors and fragrances to separate and purify volatile flavor and fragrances concentrates.

Cold sterilization can be carried out with a mixture of 90% carbon dioxide and 10% ethylene oxide, the carbon dioxide has a stabilizing effect on the ethylene oxide and reduces the risk of explosion.

SOURCE

Wow,

CO2 is a very important molecule!
#3
Part #3

CO2 a vital part of the Photosynthesis process:

Quote:Photosynthesis is the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar, which cellular respiration converts into ATP, the "fuel" used by all living things. The conversion of unusable sunlight energy into usable chemical energy, is associated with the actions of the green pigment chlorophyll. Most of the time, the photosynthetic process uses water and releases the oxygen that we absolutely must have to stay alive. Oh yes, we need the food as well!

SOURCE

With Sunlight,it produces the following,

6H2O + 6CO2 ----------> C6H12O6+ 6O2

This means that SIX molecules of CO2 are used to produce a single molecule of sugar,and some oxygen.

This alone shows that CO2 is a vital molecule to life on earth.


There are variations on the photosynthesis process that are being done all over the planet.The following is just an example:

Quote:Photosynthesis Overview

Photosynthesis involves the conversion, by various phototrophic organisms, of light energy into organic molecules, with or without the production of oxygen.

Nonoxygenic, anaerobic photosynthesis evolved^ in prokaryotes before oxygenic photosynthesis, and is found in green filamentous, green sulfur, purple sulfur, and purple nonsulfur bacteria. Photosynthesis in green sulfur bacteria such as Chlorobium tepidum takes place in the chlorosome.

SOURCE

There are many other examples of various direct or indirect photosynthetic chemical reactions found in the source link.

The Calvin Cycle,The C-3 and C-4 processes are examples of C or CO2 being used as part of the process.


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It is also used in Greenhouses to promote better plant growth:

Quote:The best time to add CO2 is from dawn to dusk. CO2 ranges from 400 to 500 ppm during the night due to plant respiration. Right after sunrise a level will drop to about 300 ppm. After three to four hours of early sun light it will drop to 100 to 250 ppm at which time growth will stop. If you add CO2 during the winter months when ventilators are closed and CO2 concentrations are low, you will get increased yield and bloom which normally happens during the spring and summer.

SOURCE

Here is an example of equipment used to increase CO2 levels in the Commercial Greenhouses.

CO2 Generators

Quote: Caron Dioxide (CO2) is one of the easiest ways to accelerate plant growth. Plants grown with supplemental CO2 can produce up to 40% more flowers or fruit. A propane or natural gas CO2 generator is the most cost effective way to add CO2 to your environment. Many greenhouses use CO2 generators to boost CO2 levels safely and economically.

SOURCE

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This is the main website.Where you can find a lot of information on the effect of CO2 enrichment on plant growth.

Plant Growth Database

Below is from the website that shows an example on the effect of increased CO2 concentration on plant growth.This one is for RICE:

Percent Dry Weight (Biomass) Increases for 300, 600 and 900 ppm
Increases in the Air's CO2 Concentration:


Quote:Plant growth responses to atmospheric CO2 enrichment are presented in tabular form as in the table below for rice. Each table begins with an abbreviated reference followed by a brief description of the experimental growing conditions and the percent increase in plant growth due to a 300, 600 or 900 ppm increase in the air's CO2 concentration. Full reference citations to each experiment can be obtained by clicking on the "Journal References" heading at the top of each table. If we have produced a Journal Review of the article, its abbreviated reference will contain a link to that review.


Plant Dry Weight (Biomass) Responses to
Atmospheric CO2 Enrichment


I chose Rice as an example to show that the use of CO2 as a growth medium in greenhouses and ultimately in the atmosphere outdoors.Beneficial to plant growth.

Click on the SOURCE link and see the tabular table,that shows increased growth for RICE,when given large increases of CO2.Increases of 300,600 and 900 ppm of CO2 are shown in the chart

In light of the basic information of the Photosynthesis process that REQUIRES CO2 as part of manufacturing the sugars,that plants needs for growth.And the fact that life on Earth is a CARBON based life.That additional CO2 in greenhouses promotes increased growth.How can anyone believe that CO2 is a Pollutant?





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