Primary Air Pollution“Bad Stuff”

So What is Primary Air Pollution Anyways?(and why do I care?)

DR. KNOW

is ASHAMED!

Recall that Air Pollutants are substances in the air at such concentration as to produce a harmful effect to humans, animals, vegetation, or materials.

So What is Primary Air Pollution Anyways?(and why do I care?)

DR. KNOW

is ASHAMED!

Air Pollutants are divided into two separate categories:

Primary Air Pollutants

Pollutants added directly to the atmosphere as a result of a given process.

Secondary Air Pollutants

Pollutants formed in the air as a result of chemical reactions.

The Big Five Primary Air Pollutants

CO

Carbon MonoxideNOx

Nitrogen Oxides

SOx

Sulfur Oxides

HCs Hydrocarbons

Particulates

The Big Five Primary Air Pollutants

NOx

SOx

HC

CO

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Particulates

So, No Cop, eH (C)Qi?

ON

to the

CHEMICALS!

Chemicals!

Chemicals!

Chemica

ls!

Carbon

Monoxid

e

The Basics

Carbon Monoxide is both toxic and undetectable to the human senses.

:CΞO:As we already know, Carbon Monoxide is formed from the incomplete combustion of hydrocarbons in oxygen-deprived environments.

Formed by 2 C(s) + O2(g) 2CO(g)

Carbon

Monoxid

e

SourcesFACT: 90 percent of all carbon monoxide production is from natural sources.

SOWhat’s the big deal about man made carbon monoxide?

Carbon

Monoxid

e

Sources

Man Made CO is still a problem!

Whereas natural sources of CO tend to be widely distributed, human production is and comes in periods oflocalized high emission rates

Most of the human emission of carbon dioxide is produced in small areas, such as downtown areas.

At rush hours, emissions are concentrated.

In areas of high man made CO concentration, there is little natural reduction of CO.

CO

CO

CO

Carbon

Monoxid

e

Effects

Nitrogen fixation ability is only affected at high levels of carbon monoxide.

Plants are Happy.

Carbon

Monoxid

e

Effects

Nitrogen fixation ability is only affected at high levels of carbon monoxide.

Hemoglobin, the oxygen carrier in animal blood cells, becomes unable to carry oxygen in the presence of carbon monoxide.

Animals and humans can die of asphyxiation.

Carbon

Monoxid

e

Effects CO:

PoisonThe

Metabolic

O2 bonds with hemoglobin to form oxyhemoglobin, which then distributes oxygen through the body. This process is easily reversible, so the hemoglobin can pick up more oxygen.

CO bonds with hemoglobin to form carboxyhemoglobin. This bond, however, is much stronger than that of oxyhemoglobin, and the reaction is hence much more difficult to reverse, thus inhibiting the ability of the hemoglobin to carry oxygen.

Carbon

Monoxid

e

Effects CO:

PoisonThe

Metabolic

Effects of Carbon Monoxide Poisoning

Incr

easi

ng c

arbo

n m

onox

ide Heart beats faster

Shortness of breath

Headaches

Fatigue, drowsiness

Coma

Respiratory failure

Death

No natural venues are so packed with CO that much more then headaches can occur.

Coma and death from CO poisoning happens in enclosed areas.

Death from carbon monoxide can be prevented by moving the victim from the enclosed area into fresh air.

The reverse reaction of carbon monoxide and hemoglobin is facilitated by the presence of ample oxygen.

Carbon

Monoxid

e

Solutions The primary man made source of carbon monoxide is the combustion engine of the contemporary automobile, but the problem is complicated by the presence other pollutants.

HOW TO REDUCE CO PRODUCTION:HOW TO REDUCE CO PRODUCTION:The Top Three Methods

3. Investigation of new fuel burning techniques and engine advancements

4. Development of new transportation technology

1. STOP DRIVING SO MUCH!

Carbon

Monoxid

e

Solutions

Chemistryof a

Cleaner Engine

Thermal Exhaust ReactorThermal Exhaust ReactorExhaust

Air

2CO + O2 2 CO2

HC + O2 C2 + H2O(g)

(not an exhaustive list)

Less CO, Less Hydrocarbons

But more greenhouse gasses

Allows usage of leaner burning engines, which minimize nitrogen oxide emissions but have increased hydrocarbon and carbon monoxide outputs.

Carbon

Monoxid

e

Solutions

Chemistryof a

Cleaner EngineCatalytic ConvertersCatalytic Converters

Platinum-based catalyst

Air compressor

2 CO +2 NO 2 CO2 +N2

Exhaust

Cooling Apparatus

Catalytic Converters have the amazing ability to convert two pollutants to mostly harmless substances.

They have, however, added six to eight hundred dollars to the price of a car and requires high octane, non-leaded, desulferized fuel.

Nitrogen OxidesBasics

NOx

There are eight known oxides of nitrogen.

Some of these oxides natural, others are man made.

The stability of the N-N triple bond in elemental nitrogen gas limits the natural production of nitrogen oxides.

The three main Nitrogen Oxides present in the air are Nitrous Oxide, Nitric Oxide, and Nitrogen Dioxide.

Formation: N2(g) +O2(g) 2NO(g) or N2(g) +O2(g) 2NO2(g)

Nitrogen OxidesBasics

N2ONitrous Oxide

Dinitrogen Oxide

NONitric Oxide

Nitrogen Monoxide

NO2

Nitrogen Oxide

Nitrogen Oxidation Number

+ 1 + 2 + 4

Lewis Structure

PropertiesColorless, non-toxic, non-flammable gas with slight odor.

Colorless, odorless, non-flammable, toxic gas

Toxic, reddish-brown, non-flammable gas with strong odor

Sources

Decomposition of nitrogen containing compounds in soil and lightning.

Majority from natural sources, twenty percent from the oxidation of nitrogen in automobiles.

Secondary pollutant from nitric oxide

:N=N=O: :N=O:Odd number of electrons

:O-N=OOdd number of electrons

Nitrogen OxidesBasics

As with CO pollution, Human Activity produces only 10 Percentof the total NOx pollution.

Localization and high emission rates, however, exacerbate the problem.

Most human NOx emissions are NO, but this is readily converted to NO2 in the atmosphere.

The majority of NO and N2O pollution is natural, from decomposition of nitrogen containing organisms, bacterial action and lightning strikes.

NOx

NOx NOx

NOx

NOxNOx

NOx

Nitrogen OxidesHeal th

Both NO and NO2 are toxic to humans and animals.Similar effects, but NO2 is worse.

NO or NO2

AAHHH

Effects of NOx are most harsh in the young and the elderly.

- Eye and nose irritation

- Breathing difficulty, respiratory distress

- Accumulation of fluid in the lungs (pulmonary edema)

- Death

(No living creatures were purposely harmed to study these effects. Study has come from low NOx pollution when smog is trapped near the earth)

Nitrogen OxidesCont ro l

The catalytic converter and the thermal exhaust reactor discussed under CO pollution both do very well to prevent the NOx pollution.

BUT in considering the control of NOx alone, it is important to note that the concentration of NOx creation is dependant upon the maximum temperature reached and the amount of oxygen gas available.

Therefore, the engines that produce less NOx are those that have designs that either limit the amount of oxygen present in the reaction or recycle cooler exhaust so that the exhaust reaction is cooled.

Just Say NO to Smog

Sulfur

Oxidez

The Low Down

This family of pollutants contains the infamous sulfur dioxide, produced in prestigious amounts, and the lesser produced sulfur trioxide.

The vast majority of primary SOx pollution is anthropogenic (big word meaning man made)

It is estimated that humans produce approximately 150 Million Tons of SO2 per year.That’s about fifty pounds per person!

A large amount of SO2, however, does come as a natural secondary pollutant.

About 200 Million Tons are produced as a natural secondary pollutant annually.

The Low Down

Sulfur

OxidezAnthropogenic SourcesAnthropogenic Sources

Combustion of Impure Coal:

Low grade coal contains as much as seven percent sulfur impurity.

Coal is polluted with both elemental sulfur, iron pyrite (FeS2), and organic sulfurs.

Combustion causes these sulfurs to mix with oxygen, thus yielding Sulfur Oxides.

Essentially: S(s) + O2(g SO2

Since sulfur is removed in the refinement of petroleum and natural gas, they are not major sources of sulfur oxide pollution.

The Major Sulfur Oxide Pollutor

Anthropogenic SourcesAnthropogenic Sources

The Low Down

Sulfur

Oxidez

Smelting Plants

I thought I SMELT somethin’ funny.

Treat sulfur ores, since many ores exist as sulfides.

The Reaction : 2 Cu2S(s) + 3 O2(g) 2 Cu2O(s) +2 SO2

Sulfuric Acid PlantsSulfur trioxide is produced by the oxidation of sulfur dioxide, and this is then reacted with water to form sulfuric acid. Some of the sulfur dioxide is released into the atmosphere rather than being properly and fully oxidized.

BOO!

The Low Down

Sulfur

OxidezAs a Natural Secondary Pollutant

In nature, decay of organic material creates hydrogen sulfide gas. This reacts with oxygen to form sulfur dioxide.

2 H2S + 3 O2 2 SO2 + 2 H2O

It can also react with ozone:

H2S + O3 SO2 + H2O

“No Chemist ever goes undead. Being the bile of living decay is not only a degrading state of being for them, but they know that every day they are releasing hydrogen sulfide, which is going up into the air and producing pollution.”

--Disowned

Health Effects

The Low Down

Sulfur

OxidezHealth Effects

Sulfur oxides have no particular health effect of their own as primary pollutants, but when they mix with water they become acid rain and acid fog, and we well know by now that that ain’t good cool digs.

Review

?

The Low Down

Sulfur

Oxidez

CONTROL that thang!The Chemistry of Controlling SOx

pollutionPurifying stuff before it’s burntHigh sulfur coal is converted to synthetic natural gas (SNG) to remove the sulfur through gasification. Sulfur is converted to hydrogen sulfide, which is easily removed.

S + H2 H2S

Precumbustion removal of sulfur from petroleum and natural gas

Hydrogen gas is bubbled through petroleum or natural gas so that becomes hydrogen sulfide, and this is acidic and easily removed.

The Low Down

Sulfur

Oxidez

CONTROL that thang!The Chemistry of Controlling SOx

pollutionCoal Washing

A physical process by which coal is ground and washed with water.

Iron Pyrite is dense, and sinks, thus removed easily.

Organic sulfur, however, is chemically bonded to carbon and cannot be removed by this physical process.

The Low Down

Sulfur

Oxidez

CONTROL that thang!The Chemistry of Controlling SOx

pollutionAfter Burning Stuff Limestone injection or fluidized beds

Powdered limestone, CaCO3, mixes with the coal in the combustion.

Heat from the combustion decomposes the limestone into calcium oxide and carbon dioxide.

Calcium oxide reacts with the SO2.

CaO + SO2 CaSO3 or 2 CaO + 2 SO2 + O2 2 CaSO4

The Low Down

Sulfur

Oxidez

CONTROL that thang!The Chemistry of Controlling SOx

pollutionWet Scrubbers

A wet-scrubber is a cleaning device that uses a liquid, usually water, to remove contaminants.

Wet scrubbers are used to remove calcium sulfates, calcium oxides, extra sulfur dioxide, and particulates.

The Low Down

Sulfur

Oxidez

CONTROL that thang!The Chemistry of Controlling SOx

pollutionWet Scrubbers

Air + Coal + CaCO3 CO2 + SO2 +CaO + O2

Alkaline Scrubber

spray

CaO + CO2 + SO2 + CaSO4 Slurry

Slurry

CO2

CaO + H2O

SO2 + CO2

Intermission

•Pressing Questions?

•Natural Needs?

ParticulatesWhat are they?

Particulates, also called aerosol, are solid particles or liquid droplets suspended or carried in the air. They are generally big enough to be seen.

Smoke and soot produced by combustion.

Dust from physical breakup of solid matter.

Asbestos from industrial plants

Metallic particles

beryllium, mercury, arsenic, lead

Give it up for the

Particulates!

ParticulatesAnd their effects on health

Unsurprisingly, most particulates invade the body of the animal through their process of respiration.

The two genres of health effects, therefore, are directly related to the nature of the chemicals.BlahBlahosis is the scaring of lung tissue by small quantities of the chemical [blahblah], thus causing respiratory difficulties and increasing risk of cancer.

Whatever Poisoning is caused by inhalation of particulates of the chemical [whatever], little tiny bits of a highly toxic chemicals which either cause damage in their tiny quantities or accumulate in the body to toxic levels.

ParticulatesAsbestos and Beryllium

Cause rather unpleasant respiratory conditions.

Asbestos comes in a bunch of tiny crystals, which, when inhaled, and fart around in the lungs indefinitely. Asbestosis occurs: lung tissue is scarred and the lining of the lungs thicken. As a result, one experiences shortness of breath and is more prone to lung cancer.

Beryllium is a toxic little devil of a chemical. When it gets in the lungs, it causes a problem called berylliosis. it inflames the tissue, causing pneumonia-like symptoms. Like asbestosis, it causes scarring of the lung tissue, and this in turn yields constant shortness of breath.

ParticulatesLead and Mercury

These puppies are poison stuff.

Lead, and more specifically, lead poisoning inhibits enzyme actions. Acute lead poisoning causes an array of problems in the human body from abdominal pain, nausea, numbness, muscle cramps, and brain damage.

Mercury, also a metabolic poison, causes mercury poisoning, also known as Minamata disease. It reacts with and inhibits the human enzyme system, thus causing nerve damage and death.

ParticulatesControlled!

Being that particulates are just a bunch of little chunks of stuff floating around in the air, they are relatively easy to remove.

Gravity settling chambers have a large tank which allows the solid dusts to settle, but this only works with large particles.

Cyclone separators are essentially large scale centrifuges. The gas is sent through a spinning cylindrical camber. Centrifugal force causes the particles to move to the outsides and fall to the bottom while the gases escape from the top.

Wet scrubbers are also effective.

Baghouse filters are mentioned in the packet, but we know nothing about them.

ParticulatesControlled!

Electrostatic precipitators are particularly important in the removal the tiny particles. More than 98 percent of the particulate matter is removed.

Gas

Solids

Hydrocarbons

Hydrocarbons tend to exist as extremely volatile liquids.

C1 to C4 are gases and C5 to C12 are liquids.

Most are produced by nature, similar to NOx and CO pollution.

Hydrocarbons are actually very similar in their nature as pollutants to those already mentioned.

(makes it easy, but boring to learn and teach.)

Hydrocarbons

Natural SourcesGeothermal Activity

Bacterial Decomposition of Organic Matter

Trees and Plants

Anthropogenic SourcesCreation of Petroleum

Incomplete Combustion of Fuel

Incomplete Combustion of Other Stuff

Hydrocarbons

Healthy fectsEfWe are immune to aliphatic hydrocarbons unless they are in large amounts.

eg. Methane may smell bad, but it ain’t killin’ ya

Watch out for the aromatic compounds, though. They cause irritation of the mucous membrane and can be fatal in large amounts.

HC

Ha ha!

Aromatic HC

Ha cough

!

Oh crap.

(Dramatization)

The Automobile Problem: A Summary-A Problem of Numbers

The Cleaner Car

-Non-Leaded Gas

-Valves

-Different Fuel to Air Ratios

-Exhaust Recycling

-Thermal Exhaust Reactors

-Catalytic Converters

Now that you have written all of this down, a summary of this information is available on the web.

http://www.geocities.com/ib_homework

Questions? Comments? Angry, Ranting, Foaming Criticisms?

Fear not. If you did not speak now, a forum will be open on the website.