CO2 Safety

90
Welcome to BOC Welcome to BOC Carbon Dioxide Safety Carbon Dioxide Safety Training Program Training Program Presented by BOC NATIONAL TRAINING CENTER

Transcript of CO2 Safety

Page 1: CO2 Safety

Welcome to BOCWelcome to BOCCarbon Dioxide SafetyCarbon Dioxide Safety

Training ProgramTraining Program

Presented byBOC

NATIONAL TRAINING CENTER

Page 2: CO2 Safety

...this seminar is designed to give participants abetter understanding of the properties,

characteristics, hazards, and installationprocedures associated with carbon dioxide.

Page 3: CO2 Safety

Our mission is for you to leave this session withnot only an increased skill level but, with an

added confidence in your ability to work safely.

Page 4: CO2 Safety

QUESTION:QUESTION:

WHAT DO WE INTEND TOWHAT DO WE INTEND TOACCOMPLISH IN THIS SEMINAR?ACCOMPLISH IN THIS SEMINAR?

Page 5: CO2 Safety

ANSWER:ANSWER:

ELIMINATE PREVENTABLEELIMINATE PREVENTABLEACCIDENTS THROUGHACCIDENTS THROUGH

EDUCATION!!!EDUCATION!!!

Page 6: CO2 Safety

WHY?WHY?

BECAUSE INFORMEDBECAUSE INFORMEDEMPLOYEES CREATE A SAFEREMPLOYEES CREATE A SAFER

WORKPLACE!!!WORKPLACE!!!

Page 7: CO2 Safety

HowHow will this be accomplished? will this be accomplished?

Page 8: CO2 Safety

LEARNING OBJECTIVESExplore what you knowSee where you need to expand yourknowledgeObtain a general knowledge about the CO2industryHave some fun while you learn

Page 9: CO2 Safety

1929: Air Reduction gained controlling interest of thePure Carbonic Company.1930: Pure Carbonic Company acquired assets andbusiness of National Carbonic Gas Company of NewJersey.1934: Pure Carbonic Company & its subsidiary Dry IceInc., purchased American Dry Ice Corporation.1935: Air Reduction acquired remaining shares ofPure Carbonic company.1936: Pure Carbonic Company becomes PureCarbonic, Inc.

BRIEF BOC/CO HISTORY

Page 10: CO2 Safety

1967: Pure Carbonic consolidated into the AIRCOIndustrial Gases Division.1979: BOC Gases acquires AIRCO.1986: AIRCO Carbon Dioxide split from AIRCOIndustrial Gases.1987: AIRCO Carbon Dioxide division is formed.1989: AIRCO acquires Americas CO2 division.1995: AIRCO switches name to BOC Gases.1995 BOC acquires ADM CO2 product.

BRIEF BOC/CO HISTORY

Page 11: CO2 Safety

It is a compound formed by the combination of carbonand oxygen atoms in a 1:2 ratio . Proportioned byweight of about 27.3% carbon to 72.7% oxygenIt is expressed by the chemical symbols CO2

It is present in the atmosphere at a concentration of0.03 percent by volumeIt is a normal product of human metabolismIt is a gas at normal atmospheric temperature andpressureA slightly acidic gasRelatively non reactive and non toxic

WHAT IS CARBON DIOXIDE?

Page 12: CO2 Safety

Synonym: Carbon anhydrideDOT Classification: Non flammable gasDOT Label: Non flammable gasTransport Canada Classification: 2.2UN Number: UN 1013 (compressed gas)

UN 2187 (refrigerated liquid) UN 1845 (solid)

WHAT IS CARBON DIOXIDE?

Page 13: CO2 Safety

PHYSICAL STATES OF CO2SolidLiquidGas

Page 14: CO2 Safety

CARBON DIOXIDEChemical symbol: CO2

Molecular weight: 44.01Color: vapor-none, solid-translucent whiteOdor: slightly pungent odortaste: bitingSpecific gravity: 1.5289 @ 1 atm @ 70 °F

Page 15: CO2 Safety

CARBON DIOXIDE Density, lbs/ft3:

solid: -109.25 °F = 97.6 lb/cu. ft.liquid: +1.7 °F, 300 psig = 63.36 lb/cu. ft.liquid: 70 °F, 830 psig = 47.35 lb/cu. ft.liquid: -69.8 °F = 73.5 lb/cu. ft.

Specific volume, lbs/ft3 :8.57 @ 1 atm @ 60 °F8.74 @ 1 atm @ 70 °F

Normal boiling point: -109.35 °F

Page 16: CO2 Safety

Carbon dioxide is stable and relatively inertSpecific heat-gas-varies (at constant pressureof 1 atmosphere):

70 °F.........................................0.20 BTU/lb(at constant volume)...............0.15 BTU/lb

CHEMICAL PROPERTIES

Page 17: CO2 Safety

CHEMICAL PROPERTIES Viscosity-gas at atmospheric pressure

& 70 °F temperature.............0.015 centipoise liquid at 0 °F..........................0.14 centipoise

Dissolved in water, carbon dioxide formscarbonic acid (H2CO3)

Becomes chemically active in moisture or highheat

Page 18: CO2 Safety

HEAT OF VAPORIZATIONSolid: -109.25 °F = 246.6 BTU/lbLiquid: +1.7 °F, 300 psig = 119.2 BTU/lbLiquid: +70 °F, 839 psig = 63.9 BTU/lb

Page 19: CO2 Safety

TRIPLE POINTTemperature/pressure combination at whichcarbon dioxide can exist simultaneously as asolid, liquid, or gas:

-69.83 °F 60.4 psig

Page 20: CO2 Safety
Page 21: CO2 Safety

CRITICAL POINTHighest temperature & pressure at which carbon

dioxide can remain a liquidCRITICAL TEMPERATURE

87.82 °FCRITICAL PRESSURE

In lbs per sq. in. abs.: 1071.6

Page 22: CO2 Safety

SOLUBILITY OF CARBON DIOXIDEReadily dissolves in most liquidsAmount is affected by temperature and pressureUnder normal conditions water dissolves its ownvolume of carbon dioxideThe greater the pressure, the more CO2 a liquid canholdOnce the pressure is released, CO2 escapes in theeffervescent characteristic of uncapped soft drinksThe colder the liquid, the more CO2 it can holdCarbon dioxide flows downhill, settles in the bottom,and displaces air

Page 23: CO2 Safety

CO IN HIGH TEMP CONDITIONS+1200 °F CO2 dissociates into carbonmonoxide and free O2

Degree of dissociation:0.000025% at 1340 °F2.1% at 3134 °F

The reaction readily reverses as thetemperature dropsAt these levels, the gas reacts with carbon andcertain metals

Page 24: CO2 Safety

Carbon Dioxide is obtained as a by-product from one ofseveral sources:

Ammonia PlantsFermentation ethanol plantsHydrogen Plants within refineriesEthylene oxideNatural gas process plantsExtractions from flue gases from the burning ofnatural gas or fuelsIn some parts of the South and Southwest, CO2 isobtained from CO2 wells at extremely highconcentrations and pressures

PRODUCTION

Page 25: CO2 Safety

Feed gas collectionCO2 compressionPurification and liquefactionRefrigeration for the liquefier unitStorage of product liquid carbon dioxideRecompression of flash carbon dioxideReactivation of dryers and adsorber dryersCarbon filterShipment of product liquid carbon dioxide

PRODUCTION PROCESS

Page 26: CO2 Safety

LIQUEFYING CARBON DIOXIDEAll impurities and foreign odors are removedfrom the gasGas is compressed and condensed usually at240 psi with ammonia refrigerationPurified liquid CO2 is shipped to customers inbulk form or converted into solid dry ice orpellets

Page 27: CO2 Safety

I. REFINERY AND AMMONIA PLANTS - (REFORMERS)

CH4 + 2H20 CO2 + 4H2METHANE + STEAM CO2 + HYDROGEN

METHANE (CH4)STEAM

NATURALGAS

STEAMREFORMER

ADSO

RB

ER

H2

STR

IPP

ER

STEAM

SO

LVE

NT

CO2 TOBOC

CO2 AND SOLVENT

TYPICAL SOLVENTS - CATACARBMEARECTISOLSELEXOLPOTASSIUM CARBONATE

Page 28: CO2 Safety

II. ETHANOL PLANTS - FERMENTATION

C6H12O6 + YEAST 2C2H5OH + 2CO2DEXTROSE ETHANOL

CO2 TOBOC

ETHANOL &DDGS

FERMENTERS

CORN MASH& YEAST

BATCH OR CONTINUOUSFERMENTERS

Page 29: CO2 Safety

III. ACID NEUTRALIZATION

CaCO3 + H2SO4 CO2 + CaSO4 + H20ARAGONITE LIMESTONE + SULFURIC ACID CO2 + GYPSUM + WATER

CO2 TO BOC

SULFURIC ACIDH2SO4

ARAGONITELIMESTONECaCO3

WASTE ACIDNEUTRALIZATION TANK

GYPSUM

Page 30: CO2 Safety

IV. COMBUSTION/COGENERATION

AIR(02 + N2)

CH4 + 2 (O2 + N2) CO2 + 2 H20 + 2N2FUEL + AIR CO2 + WATER + N2

H20

FUEL(NATURAL GASOIL OR COAL)

CO2 TO BOC

N2

ADSORBER STRIPPER

SO

LVE

NTFLUE GAS CO2 +H20+N2

CO2 AND SOLVENT

TYPICAL SOLVENTS - CATACARBMEARECTISOLSELEXOLPOTASSIUM CARBONATE

Page 31: CO2 Safety

V. CO2 NATURAL WELLS

HIGH PRESSURECO2 PIPELINE TO BOC PLANT

EARTH

HIGH PRESSURECO2 DOME

500’ TO 10,000’

Page 32: CO2 Safety

THE PROCESSEach CO2 plant is built specifically to handlethe type of impurities found in the particularfeed gas

The standard grade purity for bulk liquid is defined as:Maximum Impurities Parts per Million by Volume

Minimum % Purity 99.9 Carbon Monoxide 10Inerts 1000 Hydrocarbons (non-volatile) 10Hydrocarbons (Volatile) 50 NOx 5Water 32 Sulfur Dioxide 5Oxygen 30 Carbonyl Sulfide 0.5Ammonia 25 Hydrogen Sulfide 0.5

Page 33: CO2 Safety

PURIFICATION METHODSZinc Oxide BedsDryersAdsorbersNoble Catalyst BedsCarbon BedsMolecular Sieve BedsWater Wash ColumnsPotassium Permanganate Beds

Page 34: CO2 Safety

MAIN PROCESS COMPONENTSPurificationCompressionChilling (either by ammonia or freon)Removal of inertsLiquefaction

Page 35: CO2 Safety

BASIC PROCESS FLOWSHEET

Water

CO2

Feedgas

WaterSolubles

KMnO4Column

SulfurCompounds

OrganicsandHydrocarbons

Catalytic Combuster

CompressorZincOxideBed

H2SRemoval

OrganicRemoval

CarbonBeds

Driers

Removal of TraceQuantities of all impurities

Ammonia

CO2Condenser

DistillationColumn

Noncondensibles

Pure CO2 (L) Guard Carbonor 13x Bed

CO2 Tank

Trailer or RailCar Fill

WaterWash Column

Page 36: CO2 Safety

GRADES AND PURITYCylinder Gas: industrial grade @ 70 °F

CO2 99.5% minimumWater 25 °F dew point or drier (130 ppm by weight)

Cylinder gas: welding gradeCO2 99.5%Water -40 °F dew point (97 ppm by weight)

Bulk liquid: standard gradeCO2 99.98% minimumWater 60 °F dew point or drier (34 ppm by volume)Oil 1 ppm by weight maximumDry ice may have up to 25 white oil or propylene glycol

Page 37: CO2 Safety

CO GRADE 4.5 RESEARCHMAXIMUM IMPURITIES--PARTS PER MILLION BY VOLUME

Maximum % Purity 99.995Argon 5Carbon Monoxide 1Helium 4Hydrogen 4Krypton 0Neon 0Nitrogen 20Oxygen 4Nitrous Oxide 4THC 5Dew Point °F -86Total hydrocarbons expressed as methane.

Page 38: CO2 Safety

CARBON DIOXIDE HAZARDSHeavier than air-accumulates in low or confined areasAsphyxiant− Even in normal concentrations of oxygen carbon

dioxide can paralyze the respiratory system− Concentrations of 10% CO2 or more can cause

unconsciousness or deathThe seriousness of the symptoms of asphyxiationexperienced depends on the concentration levels andlength of exposureCarbon dioxide should only be used in areas with goodventilation

Page 39: CO2 Safety

POTENTIAL HAZARDSSafety relief valvesBall valvesLines anchored firmlyExpansion & shrinkage of linesUnauthorized personnelStatic electricityFlexible hosesConfined spaceAsphyxiation

Page 40: CO2 Safety

SYMPTOMS OF ASPHYXIATIONHeadachesSweatingRapid breathingIncreased heart beatShortness of breathDizzinessBlurred visionShakingMake it difficult to leave the area

Page 41: CO2 Safety

Group Classification Numberof

Fatalities

Toxic Atmospheres in confined work spaces 82

Asphyxiating atmospheres in confined work spaces 67

Other hazards present in confined work spaces 24

TOTAL FATALITIES 173

(not all due to nitrogen/argon)

FATALITIES DUE TO ASPHYXIATION

Page 42: CO2 Safety

PREVENTATIVE MEASURESExercise caution when entering areas toensure proper oxygen/ CO2 levelsMonitor levels in all such areasAn alarm should be sounded if either theoxygen level drops or CO2 levels risesDuring down time and maintenance use:− Entry permits− Lock out procedures− Confined space entry standards

Page 43: CO2 Safety

PREVENTATIVE MEASURES All equipment using CO2 must be equippedwith a properly designed exhaust system System design must ensure that CO2concentrations in work areas never exceedsthe allowable exposure limits Monitors may be set up to not only sound analarm but turn on ventilation if needed (doneby customer only).

Page 44: CO2 Safety

EXPOSURE TO CARBON DIOXIDEResponse varies from person to personIt is not constant with the same person atdifferent timesSince CO2 is the regulator for the body’sbreathing, a change in levels will cause animmediate responseExertion will burn oxygen content within aperson, thus increasing the body’sconcentrations of CO2

Page 45: CO2 Safety

EMPLOYEE EXPOSURE LIMITS FOR CO2

AGENCY MAXIMUM CONCENTRATION(IN AIR)

EXPOSURE TIME LIMIT

Occupational Safety andHealth Administration

1/2% or 5,000 parts per million(ppm)

Per 8 hour work shift/40 hour week

American Conference ofGovernment IndustrialHygienists

3% or 30,000 parts per million(ppm)

5% or 50,000 parts per million(ppm)

15 minute period

immediately dangerous to life andhealth (IDLH)

Page 46: CO2 Safety

HANDLING LEAKS & EMERGENCIESVentilate areas to prevent the formation of toxicconcentrations of carbon dioxide.If carbon dioxide content exceeds 3% you must wearan SCBA to enter that area.Avoid contact of the skin or eyes with cold carbondioxide.Evacuate the immediate area if the leak is large.If water spray is used to dissipate leak, a dense fogmay form as well as carbonic acid.Leak will dissipate itself given time if the ambianttemperature is above freezing.

Page 47: CO2 Safety

PREPARING FOR AN EMERGENCYPre-arranged emergency plan including:

TransportationMedical attentionFirst aid techniques for CO2

Evacuation planPerimeter security

Personnel should be trained to use approved skinand respiratory protectionPersons required to shut off the CO2 source shouldbe properly trained and adequately protected

Page 48: CO2 Safety

COLD CONTACTSolid (dry ice) and liquid CO2 are normallyvery cold. Contact with these may result infrostbiteContact could also result in lesions or moreserious injury from deep freezing of thetissuesContact should also be avoided with gaseousCO2 coming out of a pressurized containersince this gas can also be very cold

Page 49: CO2 Safety

FIRST AID FOR COLD CONTACTFrozen tissues are painless and appear waxyyellowRemove restrictive clothing and immerseaffected part in warm water (approximately105°F)Do not rub frozen parts, tissue damage mayresultNever use dry heat

Page 50: CO2 Safety

If the exposure has been massive and generalbody temperature is depressed, immerse patientin a warm water bathSupportive treatment for shock should beprovidedMedical assistance should be obtained as soon aspossibleIf the frozen part thaws before medical attention isobtained, cover with loose, dry, sterile dressingAlcoholic beverages or smoking are prohibited.Warm drinks and food may be administered

FIRST AID FOR COLD CONTACT

Page 51: CO2 Safety

CARBON DIOXIDE SAFETY APPARELWear clothing resistant totemperatures of -109 °FLoose fitting glovesSteel toed shoesHard hatEar protectionEye protectionLong sleeves (should not berolled up while working )

Page 52: CO2 Safety

CARBON DIOXIDE APPLICATIONSDry ice pelletsCarbonationRefrigerationCrude Oil RecoverypH controlDeflashingIndustrial cleaning

Page 53: CO2 Safety

ElectronicsPreservingBaked goods manufacturingFumigationInert blanketing and purgingShielding gasSolvent

CARBON DIOXIDE APPLICATIONS

Page 54: CO2 Safety

CARBON DIOXIDE APPLICATIONSMetallurgy (steel making)TextilesPressurizationPapermakingPlasticsAgricultureHorticultureChemical

Page 55: CO2 Safety

LIQUID LEVEL GAUGESDifferential pressureDensityNPSHDead leg

Page 56: CO2 Safety

CARBON DIOXIDE RECEIVERCONFIGURATION

VESSEL

PRESSURE

INSULATION

PIPING

PRESSURE BUILDINGVAPORIZER

COOLING

HORIZONTAL/VERTICAL

CARBON STEEL

350 PSIG (MAX)

FOAMBLOCKSPRAY

SCHEDULE 80 CARBON STEEL

ELECTRICAUXILIARY

MECHANICAL

Page 57: CO2 Safety

SPECIFICATIONS ON TOMCO EQUIPMENTStorage unit capacities: from one ton to 100 ton orgreater.Pressure vessel: ASME coded for maximum workingpressure of 350 psig, Code Specifications V1 1 1,Division 1.Piping: schedule 80 seamless pipe, 2,000 lb. forgedsteel fittings, ball type valves.Safeties: ASME approved direct spring loaded or pilotoperated, sized for unconfined outdoors installations.Insulation: 4” polyurethane.Outer jacket: 063” aluminum.

Page 58: CO2 Safety

TOMCO STORAGE VESSELSVaporizers (optional): Steam or electriccapacities to 6,000 lb./hr and greaterLiquid level gauges: Differential pressureindicators. Usually Barton gauges.Pressure gauges: 0-600 psig with 6” dialStyle: Vertical or horizontalMinimum design temperature: -40 °FElectrical: 208, 230/460 three-phase 60 cyclesUL listed components

Page 59: CO2 Safety

MAINTAINING PRESSURE IN LIQUID CO2RECEIVERS - HORIZONTAL CONFIGURATION

Page 60: CO2 Safety
Page 61: CO2 Safety

CARBON DIOXIDE DELIVERY PIPING

Page 62: CO2 Safety

PB SIDEARM VAPORIZER

Page 63: CO2 Safety

STEAM VAPORIZER

Page 64: CO2 Safety

DIRECT TO PROCESS VAPORIZER

Page 65: CO2 Safety

FIGURE 2

Page 66: CO2 Safety

GENERAL SITE REQUIREMENTSAtmospheric conditionsClearance from exposuresUnderground interferenceOverhead interferenceTrailer access

Page 67: CO2 Safety

UTILITIESElectricalPhoneLighting

Page 68: CO2 Safety

REGS GOVERNING INSTALLATIONSFederal LawsState and Local LawsBoiler Pressure Vessel LawsIndustry GuidelinesInsurance CompaniesOther Experience

Page 69: CO2 Safety

GUIDELINES & AGENCIESBOCA: Building Officials Code AssociationCGA: Compressed Gas AssociationNFPA: National Fire Protection AssociationOSHA: Occupational Safety Health

AdministrationUFC: Uniform Fire CodeNEC: National Electric CodeSFPC: Standard Fire Prevention Code

Page 70: CO2 Safety

SBCCI: Southern Building Code Congress International

UBPVL:Uniform Boiler and Pressure Vessel Laws

ASME: American Society of Mechanical Engineers

ANSI: American National Standards InstituteFDA: Food & Drug AdministrationBOC Gases Installation StandardsBOC Gases National Training Center

GUIDELINES & AGENCIES

Page 71: CO2 Safety

CGA REGS FOR COCGA G-6 “Carbon Dioxide”CGA G-6.1 “Standard for Low Pressure Carbon DioxideSystems at Customer Sites”CGA G-6.2 “Commodity Specifications for CarbonDioxide”CGA G-6.3 “Carbon Dioxide Cylinder Filling andHandling Procedures”CGA G-6.4 “Safe Transfer of Low Pressure Liquefied Carbon Dioxide in Cargo Tanks, Tank Cars, and Portable Containers”CGA G-6.5 “Standard for Small Stationary LowPressure Carbon Dioxide Systems”

Page 72: CO2 Safety

CGA HB-3 “Handbook of Compressed Gases”CGA P-1 “Safe Handling of Compressed Gases in

Containers”CGA P-14 “Accident Prevention in Oxygen-Rich and

Oxygen-Deficient Atmospheres”CGA S-1.1 “Pressure Relief Device Standards

(Cylinders for Compressed Gases)”CGA S-1.2 “Pressure Relief Device Standards (Cargo

and Portable Tanks for Compressed Gases)”CGA S-1.3 “Pressure Relief Device Standards

(Compressed Gas Storage Containers)”

CGA REGS FOR CO

Page 73: CO2 Safety

EQUIPMENT AND COMPONENTSSuitable for temperatureSuitable for pressureCompression fittingsStainless steelMaterial constructionLeak rate

Page 74: CO2 Safety

SUITABLE MATERIALS FOR COSchedule 80 threaded steel pipeForged steel fittings rated at 3000 psfSeamless schedule 40 steel pipe, welded jointsStainless steelCopperBrass

Page 75: CO2 Safety

LABELING AND MARKINGSThe Corporate Identification LogoProduct IdentificationCAS NumberUNC NumberSafety Venting DecalsProduct Hazard Warning

Page 76: CO2 Safety

Pipeline LabelingAuthorized PersonnelPressure Vessel IdentificationCorporate Identification NumberEmergency Information Valve and ComponentIdentificationAnnual Safety Inspection

LABELING AND MARKINGS

Page 77: CO2 Safety

Carbon dioxideCauses severe burnsLiberates a gas which may cause suffocationAvoid contact with skin and eyes-- do not tasteDo not put in stopped or closed containersUse and store only in well ventilated areasLiquid under pressureEmergency phone numbers

SIGN INFORMATION

Page 78: CO2 Safety

EQUIPMENT INSPECTION POLICYEquipment must be inspected yearlySafeties must be changed out and re-testedevery five years

Page 79: CO2 Safety

CUSTOMER TRAININGMSDS (Material Safety Data Sheet)General site reviewEmergency contact information

Page 80: CO2 Safety

REFRIGERATION LAWSREFRIGERATION LAWS

Page 81: CO2 Safety

To remove refrigerant in any condition from asystem and store it in an external container

without necessarily testing or processing it inany way.

RECOVER

Page 82: CO2 Safety

To reduce contaminants in used refrigerant byoil separation, non-condensable removal and

single or multiple passes through deviceswhich reduce moisture, acidity and

particulate matter, such as replaceable corefilter-dryers. This term usually applies to

procedures implemented at the field job siteor in a local service shop.

RECYCLE

Page 83: CO2 Safety

To reprocess refrigerant to new productspecifications by means which may include

distillation. Chemical analysis of therefrigerant is required to determine that

appropriate product specifications are met.This term usually implies the use of

processor or procedures available only at areprocessing or manufacturing facility.

RECLAIM

Page 84: CO2 Safety

FACTORS-RECOVERED REFRIGERANTReason system is being servicedCondition of refrigerant and systemEquipment manufactures' policiesRefrigerant cleaning capability of recyclingequipmentFeasibility and owner's preference

Page 85: CO2 Safety

RECOVERED REFRIGERANT OPTIONSOption 1: Put refrigerant back into the system withoutrecycling it.Option 2: Recycle refrigerant and put it back into thesystem from which it was removed or back into asystem with the same owner.Option 3: Recycle the refrigerant, test to verifyconformance to ARI Standard 700 prior to reuse in adifferent owner's equipment provided that therefrigerant remains in the contractor's custody andcontrol at all times from recovery through recycling toreuse.Option 4: Send refrigerant to a certified reclaimer

Page 86: CO2 Safety

CONTAMINANT LEVELSBecause there are no means at this time todetermine all contaminant levels (other than bylaboratory testing), assurance that thesecontaminant levels are not exceeded can beaccomplished by:

The proper use and maintenance of refrigerantrecovery/recycling equipment that is capable ofrecycling refrigerants to or below the levels in thetable orLaboratory analysis (the appendix to ARIStandard 700 describes laboratory analysisprocedures).

Page 87: CO2 Safety

MAXIMUM CONTAMINANT LEVELS-RECYCLEDREFRIGERANT / SAME OWNER’S EQUIPMENT

CONTAMINANTS LOWPRESSURESYSTEMS

R-12 SYSTEMS ALL OTHERSYSTEMS

Acid Content byWeight

1.0 ppm 1.0 ppm 1.0 ppm

Moisture by Weight 20 ppm 10 ppm 20 ppm

Non Condensable Gas(By Volume)

N/A 2.0 percent 2.0 percent

High Boiling Residues(vol.)

1.0 percent .02 percent .02 percent

Chlorides by SilverNitrate test

No turbidity Visually clean Visually clean

Particulate Visually clean Visually clean Visually cleanOther Refrigerants 2.0 percent 2.0 percent 2.0 percent

Page 88: CO2 Safety

SALE OF REFRIGERANTSUsed refrigerants shall not be sold, or used ina different owner's equipment, unless therefrigerant has been analyzed and found tomeet requirements of ARI Standard 700 (latestedition), “Specifications for Fluorocarbon andOther Refrigerants".

Page 89: CO2 Safety
Page 90: CO2 Safety

NITROGEN vs CARBON DIOXIDEBoth asphyxiants, but CO2 is considered toxicLiquid CO2 is not subject to the same level of refrigerantlosses associated with LN2Vacuum insulated pipe is sometimes considered necessaryfor longer LN2 lines (usually at twice the piping cost)Phase separators sometimes necessary for LN2 lines & forCO2 lines in chilling applicationsLN2 has a greater temperature difference available (-320 °Ffor LN2 vs -109 °FLN2 contains about 12% greater refrigeration capacity perunit weight than CO2For bulk tank installations, LN2 usually requires less capital