Patrick Urbankowski Drexel University May 2018 Adapted from Boris Dyatkins presentation Disclaimer If you will conduct experiments that involve either ammonia or chlorine gases you ID: 914279
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Slide1
Chlorination/Ammoniation Setup Safety
Patrick UrbankowskiDrexel UniversityMay 2018Adapted from Boris Dyatkin’s presentation
Slide2Disclaimer
If you will conduct experiments that involve either ammonia or chlorine gases, you MUST
receive training, a fit test, and receive your own respirator provided by the Department of Environmental Health & Safety (
EHS
) and
Med-Tex Services. This must be repeated annually.Contact Joe Nihill (jrn43@drexel.edu)Must be clean-shaven prior to testing.Purge tubes with inert gas (e.g. Ar) prior to ammoniation or chlorination.
Slide3Ammoniation
Slide4Ammonia Handling
Airgas
Ammonia is a combination of liquefied air and hydrogen
N
2
+ 3 H
2
2 NH
3
In tanks, anhydrous ammonia is liquid.
When released from a tank, the liquid transforms to gas.
Slide5Ammonia is all around (and in) us
Airgas
In small amounts, ammonia is one of the building blocks of mammal life
Ammonia is not a metabolic poison
Not determined to be a carcinogen
It is still, however,
lethally dangerous
.
Slide6Detecting ammonia
Airgas
The most recognizable property of ammonia is:
Smell
Strong and irritating smell is the best warning sign that ammonia is present
Rule of Exposure
5 ppm
You can
smell
it
50 ppm
It can
harm
you
–
Long Term Exposure
300 ppm
IDLH
–
Immediate Danger to Life & Health
5,000 ppm
It can kill you
If you can smell ammonia outside of the furnace, move away from the area and alert necessary personnel in the lab
Slide7Consequences of exposure (in ppm)
Airgas
Slide8Ammonia exposure
Airgas
Exposure to liquid anhydrous ammonia or high concentrations of ammonia vapor cause:
Blindness
Dehydration of body tissue
Chemical burns
Frostbite
Slide9Ammonia Characteristics
Airgas
Anhydrous = without water
Pungent, colorless gas
Stored as liquid under pressure
UN identification number is 1005 (on shipping documents and DOT Energy Response Guide
Pressure varies greatly with temperature
50 °F = 75 psig
90 °F = 165 psig
Slide10Ammonia Characteristics
Airgas
Ammonia is sensitive to pressure and temperature
A small volume of liquid anhydrous ammonia produces a large volume of gas at atmospheric pressure
Ammonia has a limited flammability range
15-28% in air generally found only in confined space
Mixtures of oil and ammonia may reduce lower level to 8%
Ammonia has a
very strong affinity for water
1 gallon of water will absorb 1,300 gallons of ammonia vapor by volume.
Slide11Ammonia Loves Water
Airgas
BAD
:
Ammonia attacks the moist areas of the body
The body is mostly water
The eye is 90% water
Exposure can result in immediate eye damage
Slide12Ammonia Loves Water
Airgas
GOOD
:
Water can be used for first-aid treatment for NH
3
exposure
Water can be used to absorb an ammonia vapor release.
This is why the tubing exiting an ammoniation tube ends in a beaker of water.
Water should
never
be mixed with liquid ammonia. This will result in a violent reaction and vapor release.
Slide13Water –
First Aid for AmmoniaLarge quantities of water (15 min. of continued flushing) are recommended for washing contaminated skin areas or for eye contact.Rule: For an eye exposed to ammonia, hold the eyelid open
and wash for 15 minutes with water
Airgas
Slide14First Aid Treatment for Ammonia
Inhalation:Remove from exposureAdminister artificial respiration or oxygen if breathing has stopped.
Seek medical attention
Skin contact:
Immediately flush with large quantities of water and continue for 15 minutes. Do not remove clothing if frozen to skin
Seek medical aid.Airgas
Slide15First Aid Treatment for Ammonia
Eye contact:Immediately flush with large quantities of water. Continue for 15 minutes.
Seek medical aid.Ingestion:
Do not induce vomiting. Give 1-2 glasses of milk or water
Seek medical
Airgas
Slide16Personal Protective Equipment (PPE
) Requirements for AmmoniaAirgas
Full
facepiece
respirator is highly recommended during use, but it is at the very least
REQUIRED
to have annual training and possess this type of respirator.
Slide17Skin Damage
Critical skin damage begins at 24.8 °F and becomes irreversible at -18.5 °FThe degree of tissue injury is proportional to the duration and
concentration of exposureAlkaline burns go
deeper
than acid burns
Alkali burns are yellow, soapy, and soft in texture. When burns are severe, skin turns black and leathery.Airgas
Slide18What NOT to wear
NEVER wear contact lenses when working near ammoniaAmmonia may become trapped behind the contact lens, increasing the risk of damage to the eye and reducing the effectiveness of
the eyewash.
Airgas
Slide19Chlorination
Slide20Chlorine Synthesis
Primary usage in DNICDC synthesisMC(s) + 2Cl2(g) MCl
4(g) + C(s)
Slide21Chlorine properties
Boiling point: -34.04 °CCompressed tanks are liquid chlorineChlorine expands when
released during operationDensity: 3.2 g/L
More dense than air
Will flow towards the floor (heavy)
AppearanceLiquid: blue-amber (not likely to be seen)Gas: pale green-yellow
Slide22Main hazards of chlorine
Slide23Main reaction:
Cl2 + H2O ->
HCl or HClO
(water in air or on surface)
Corrosive to metals and living tissue
Primary afflicted organs: Lungs (inhalation)Symptoms: coughing, wheezing, shortness of breath, difficulty breathing, tightening in chest, pulmonary edema (fluid in lungs)) Long-term exposure: chronic asthma Skin- Symptoms: irritation, burning- Long-term exposure: tissue necrosis, scarring Eyes Symptoms: irritation, burning in eyes
Long-term exposure: permanent eye damage possible
Used as a chemical weapon in WWI,
Several subsequent conflicts
Slide24Inhalation Hazards
Dangerous levels: 30 ppm: shortness of breath, chest pain, possible vomiting 40-60 ppm: lung irritati
on, accumulation of fluid in lungs
>50 ppm: loss of consciousness
> 100 ppm: lethal dose possible
Average lethal dose: 300-1000 ppm for 30 minutes
Slide25Immediate Response
Smell detected at 1 ppm limitMove victim to fresh airCall EH&S Immediately! Give artificial respiration and CPR (
if trained) if there is no breathing or no pulse
Slide26Additional Hazards
Chlorine is a strong oxidizer (like oxygen) but is not flammable Chlorine reacts violently with oil and grease Chlorine
corrodes sensors and electronics and damages lab equipment
Slide27Standard Operation
1-25 ppm Full face respirator with cartridges (yellow) Standard PPE & rubber gloves
25-100 ppm Full self-contained breathing apparatus (only used by EH&S and emergency personnel)
All respirator users must undergo annual certification
Slide28Compressed Cylinder Operation
Only certified users may use the chlorination setup Tank requires specialty regulator and valveValve is wrench-operated (not standard wheel)
Respirator protection must be worn for changing cylindersWasher between tank and regulator must be replaced when changing tanks
Back (tank) pressure is low (80 PSIG) due to compressed liquid state
• Forward pressure cannot exceed 10 PSIG
Slide29Filtration Flask Operation
Reaction uses excess Cl2:Chlorine must bubble into neutralizing media • Flasks: 5M
NaOH (400grams/2 Liters)Content is
highly corrosive
• Neutralization: Cl
2 bubbles should react/dissolve into solution prior to reaching surface • Standard rules: 2-3 small furnace runs, 1-2 large furnace runs • Content is hazardous wasteSodium hydroxideSodium chlorineSodium hypochlorite (bleach) *Metal Carbide* oxide
Slide30Chlorine System Operation
Flow rates– 1 bubble/second for small furnaces (F1, F2) – 2-4 bubbles/second for large furnace (LTF) Ensure system is sealed and leak-proof prior to operating chlorine
Purge system with Ar prior to any Cl
2
flow (ensures system integrity)
Purge system with Ar after chlorination for at least 3 hours prior to opening system
Slide31Purging/Stabilizing Agents
H2 or NH3 ammonia gas Gases are reducing agents (may violently react with excess Cl
2 in system – purge system with
Ar
prior to use)
Must be stored in separate storage cabinet from oxidizing chlorine or other oxidizers
Slide32Typical problem sources
Leaks in system Cracked glass, old fittings, improperly secured or tightened down fittings BlockagesMetal chlorides hydrolyze when they reach filtration flask, form solid products that block tubes
Chlorine gas escaping filtration flask Excessive flow rates
Expired
base solution