Transcript Effects of Cycloalkanes in Human and Environment

Effects of Alkanes and
Cycloalkanes in Human and
Environment
Advantages and Disadvantages
By: Emalyn Llona
Advantages of Alkanes
Some advantages ...
• Probably the major use/advantage of Methane is that it is
what we call "Natural Gas," and as such is a MAJOR fuel
worldwide! We all are aware of the tremendous value of a
relatively easily delivered fuel to our homes, businesses, and
factories.
• Methane [CH4] is also is a basic "building block" for literally
dozens, or possibly hundreds, of compounds which we use to
make literally thousands of products we use every day. One
example is the multitude of different plastics.
• In the "new" technology vehicles designed to burn
Hydrogen, billions of tons of natural gas [Methane]
will be thermally "steam cracked" into Hydrogen for
use as a motor vehicle fuel, but I don't know yet
what plans "they" have for the billions of tons of
pure carbon which will be left over from the cracking
process.
Disadvantages of Alkanes
Some disadvantages ...
• It is a main contributor to global warming, as it is one of the
"greenhouse" gasses which cause entrapment of infrared
energy [heat] within the atmospheric envelope around the
Earth.
• It is very dangerous to the human body, in that high enough
concentrations in the air can result result in suffocation of air
breathing creatures, AND in the proper concentration in the
air, it is very highly explosive!
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Examples of Alkanes we use
everyday
Methane
Ethane
Propane
Butane
Advantages of methane
• Methane is used in industrial chemical
processes and may be transported as a
refrigerated liquid (liquefied natural gas, or
LNG).
Disadvantages of Methane
• affects the degradation of the ozone layer.
• Methane in the Earth's atmosphere is an important
greenhouse gas with a global warming potential of
25 compared to CO2 over a 100-year period
(although accepted figures probably represents an
underestimate.
• it is extremely flammable and may form explosive
mixtures with air.
• violently reactive with oxidizers, halogens, and some
halogen-containing compounds.
• an asphyxiant and may displace oxygen in an
enclosed space.
• Methane off-gas can penetrate the interiors of
buildings near landfills and expose occupants to
significant levels of methane. Some buildings have
specially engineered recovery systems below their
basements to actively capture this gas and vent it
away from the building.
Traditionally, industrial nations have relied upon fossil
fuels like oil, coal and natural gas to power our economies.
Fossil fuels are an example of this type of energy resources.
There are many specific types of non-renewable energy,
including:
* Various types of coal such as anthracite, bituminous coal, and
lignite
* Petroleum products used to make gasoline, diesel fuel, and
heating oil
* Natural gas, the methane in which is extracted and used as fuel
* The uranium ore used in nuclear fission reactors is a nonrenewable energy resource
Advantages:
1. Widely available, at least currently
2. Simple to use and engineer, given that it is based upon a simple
combustion process
3. Inexpensive
4. Easy to transport and distribute
Disadvantages:
1. Contributing to the warming of the planet, or global warming
2. Causes pollution such as acid rain, which hurts animals and plants
around the world
3. Potential source of global political unrest, given that many nations are
reliant upon other nations for these non-renewable energy resources
Ethane
Ethane is isolated on an industrial scale from natural gas,
and as a byproduct of petroleum refining. Its chief use is as
petrochemical feedstock for ethylene production.
After methane, ethane is the second-largest component
of natural gas. Natural gas from different gas fields varies in
ethane content from less than 1% to over 6% by volume.
Today, however, ethane is an important petrochemical
feedstock, and it is separated from the other components of
natural gas in most well-developed gas fields. Ethane can also
be separated from petroleum gas, a mixture of gaseous
hydrocarbons that arises as a byproduct of petroleum
refining.
• The chief use of ethane is in the chemical industry in
the production of ethene (ethylene) by steam
cracking. When diluted with steam and briefly
heated to very high temperatures (900 °C or more),
heavy hydrocarbons break down into lighter
hydrocarbons, and saturated hydrocarbons become
unsaturated.
• Experimentally, ethane is under investigation as a
feedstock for other commodity chemicals. Oxidative
chlorination of ethane has long appeared to be a
potentially more economical route to vinyl chloride
than ethene chlorination. Many processes for
carrying out this reaction have been patented, but
poor selectivity for vinyl chloride and corrosive
reaction conditions (specifically, a hydrochloric acidcontaining reaction mixture at temperatures greater
than 500 °C) have discouraged the commercialization
of most of them.
Safety
• At room temperature, ethane is a flammable gas. When mixed with air
at 3.0%–12.5% by volume, it forms an explosive mixture.
• Some additional precautions are necessary where ethane is stored as a
cryogenic liquid. Direct contact with liquid ethane can result in severe
frostbite. In addition, the vapors evaporating from liquid ethane are,
until they warm to room temperature, heavier than air and can creep
along the ground or gather in low places, and if they encounter an
ignition source, can flash back to the body of ethane from which they
evaporated.
• Containers recently emptied of ethane may contain insufficient oxygen
to support life. Beyond this asphyxiation hazard, ethane poses no
known acute or chronic toxicological risk. It is not known or suspected
to be a carcinogen.
SAFETY FOR ODORIZED
PROPANE
Identification
Product Name: Odorized Commercial Propane
Chemical Name: Propane
Chemical Family: Paraffinic Hydrocarbon
Formula: C3H8
Synonyms: Dimethylmethane, LP-Gas, Liquefied
Petroleum Gas (LPG), Propane, Propyl Hydride
Hazards of Propane
Flammable liquefied gas under pressure. Keep
away from heat, sparks, flame, and all other ignition
sources. Vapor replaces oxygen available for
breathing and may cause suffocation in confined
spaces. Use only with adequate ventilation. Reliance
upon detection of odor may not provide adequate
warning of potentially hazardous concentrations.
Vapor is heavier than air; may collect at low levels.
Liquid can cause freeze burn similar to frostbite.
POTENTIAL HEALTH EFFECTS INFORMATION
ROUTES OF EXPOSURE:
Inhalation: Asphyxiation. Before suffocation could occur, the lower
flammability limit of propane in air would be exceeded, possibly causing
both an oxygen-deficient and explosive atmosphere. Exposure to
concentrations >10% may cause dizziness. Exposure to atmospheres
containing 19% or less oxygen will bring about unconsciousness without
warning. Lack of sufficient oxygen may cause serious injury or death.
Eye Contact: Contact with liquid can cause freezing of tissue.
Skin Contact: Contact with liquid can cause frostbite.
Skin Absorption: None.
Ingestion: Ingestion is not expected to occur in normal use. However, liquid
can cause freeze burn similar to frostbite.
Chronic Effects: None
Ecological Information
No adverse ecological effects are expected.
Propane does not contain any Class I or Class II
ozone-depleting chemicals. Propane is not listed as a
marine pollutant.
Butane
Hazards of Butane
• Effects on Animals
Contact with liquid butane can cause frostbite. This gas is also an
anesthetic and aphyxiant in animals at very high concentration. Although
butane is mildly to moderately irriating to rabbit skin, it does not produce
ocular or respiratory tract irritation. Exposed dogs to high concentration of
liquid butane can cause stroke, increase cardiovascular disease, left
ventricular and aortic pressures.
Effects on Human
• Transient blurring may result if liquid butane is accidentally sprayed on
eyes from a cigarette lighter.
• However, contact of butane gas on eyes may not cause irritation.
• But contact with the liquefied form may cause frostbite into the eyes and
skin.
• Exposure to high concentration within a short period of time may cause
drowsiness but does not appear to cause systematic effects.
• Inhalation of children of aerosol sprays which contain butane, isobutane,
and propane can cause to seizures, hypotension and cardiovascular defect.
• Visual hallucinations, increased irritability, and social withdrawal are some
effects to adolescents which are exposed to this gas everyday.
• Another effect to people who are exposed to high concentration can affect
central nervous system, causing narcosis and aphyxiation,
Examples of Cycloalkanes
• Cyclopropane
• Cyclohexane
Cyclopropane
• Cyclopropanes are a class of organic compounds containing a
cyclopropane ring, in which one or more hydrogen atoms are replaced by
other groups. These compounds are found in biomolecules and many
synthetic substances. For instance, the pyrethrum insecticides found in
certain Chrysanthemum species contain a cyclopropane ring. Many
modified derivatives, called pyrethroids, have been prepared
• Cyclopropane is an anaesthetic when inhaled. In modern anaesthetic
practice, it has been superseded by other agents, due to its extreme
reactivity under normal conditions: When the gas is mixed with oxygen
there is a significant risk of explosion.
Anaesthesia
Cyclopropane was introduced into clinical use by the American
anaesthetist Ralph Waters who used a closed system with carbon dioxide
absorption to conserve this then-costly agent. Cyclopropane is non-irritant
and sweet smelling. It is a relatively potent agent and has a blood gas
partition coefficient comparable to nitrous oxide. This meant induction of
anaesthesia by inhalation of cyclopropane and oxygen was rapid and not
unpleasant. Prolonged anaesthesia caused "cyclopropane shock" during
recovery and for this reason, and its explosive nature, it was latterly used
only for induction of anaesthesia. Cylinders and flow meters were
coloured orange.
• Because of the strain in the carbon-carbon bonds of cyclopropane, the
molecule has an amount of potential energy, indicated by its high heat of
combustion.
• At room temperature, sufficient volumes of liquified cyclopropane will
self-detonate. Cyclopropane is dangerous to handle and manufacture, and
is no longer used for anaesthesia.
Cyclohexanes
Cyclohexane is a colorless, flammable liquid. It occurs naturally in
petroleum crude oil, in volcanic gases, and in cigarette smoke.
Exposure to cyclohexane can occur in the workplace or in the environment
following releases to air, water, land, or groundwater.
Exposure can also occur when people use products that contain
cyclohexane or when they smoke cigarettes. Cyclohexane enters the body
when breathed in with contaminated air or when consumed with
contaminated food or water. It can also be absorbed through skin contact.
Cyclohexane is not likely to remain in the body due to its breakdown and
removal in exhaled air and in urine.
Cyclohexane evaporates when exposed to air. It dissolves when
mixed with water. Most direct releases of cyclohexane to the
environment are to air. Cyclohexane also evaporates from water and soil
exposed to air. Once in air, it is expected to break down to other
chemicals. Because it is a liquid that does not bind well to soil,
cyclohexane that makes its way into the ground can move through the
ground and enter groundwater. Plants and animals living in environments
contaminated with cyclohexane can store small amounts of the chemical.
How cyclohexane affect human and
the environment?
Effects of cyclohexane on human health and the environment depend
on how much cyclohexane is present and the length and frequency of
exposure. Effects also depend on the health of a person or the
condition of the environment when exposure occurs. Breathing large
amounts of cyclohexane for short periods of time
adversely affects the human nervous system. Effects range from
headaches to anesthesia, tremors, and convulsions. Contact with
cyclohexane liquid or vapor can damage the eyes. These effects are not
likely to occur at levels of cyclohexane that are normally found in the
environment.
Human health effects associated with breathing or otherwise
consuming smaller amounts of cyclohexane over long periods of
time are not known. Information about cyclohexane's potential to
cause cancer, developmental effects, or reproductive effects either
does not exist or is not adequate. Studies show that repeat
exposure to large amounts of cyclohexane in air causes nervous
system effects, eye damage, and respiratory effects in animals. The
cyclohexane industry is no studying how its chemical affects the
reproductive system and the development of the fetus of animals.
Cyclohexane by itself is not likely to cause environmental
harm at levels normally found in the environment.
Cyclohexane can contribute to the formation of
photochemical smog when it reacts with other volatile
organic carbon substances in air.
Hazard Identification
Inhalation
Breathing high concentrations may be harmful. Mist or vapor can
irritate the throat and lungs. Breathing this material may cause central
nervous system depression with symptoms including nausea, headache,
dizziness, fatigue, drowsiness, or unconsciousness.
• Eye Contact
This product can cause transient mild eye irritation with short-term
contact with liquid sprays or mists. Symptoms include stinging, watering,
redness, and swelling.
• Skin Contact
This material can cause skin irritation. The severity of irritation will
depend on the amount of material that is applied to the skin and the
speed and thoroughness that it is removed. Symptoms include redness,
itching, and burning of the skin. Repeated or prolonged skin contact can
produce moderate irritation (dermatitis).
• Ingestion
If swallowed, this material may irritate the mucous
membranes of the mouth, throat, and esophagus. It can be readily
absorbed by the stomach and intestinal tract. Symptoms include a
burning sensation of the mouth and esophagus, nausea, vomiting,
dizziness, staggered gait, drowsiness, loss of consciousness and
delirium, as well as additional central nervous system effects. Due
to its light viscosity, there is a danger of aspiration into the lungs
during swallowing and subsequent vomiting. Aspiration can result in
severe lung damage or death. Cardiovascular effects include
shallow rapid pulse with pallor (loss of color in the face) followed by
flushing (redness of the face).
• Chronic Health Effects
Prolonged and/or repeated contact may cause skin irritation and
inflammation. Symptoms include defatting, redness, blistering, lesions,
and scaly dermatitis.