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Acetylene
Acetylene
Acetylene
Dissociation MechanismAcetylene (C2H2)
Hydrocarbon
Heat
C (ad) 2H (ad)
H2 (gas)
Carbon Diffusion
Steel Surface
+
+
Acetylene
Dissociation Products
Typical Dissociation Products
Average Carbon Flux. g/m2h
Acetylene C2H2 2C + H2 150
Methane CH4 2H2 + C <5
Ethylene C2H4 CH4 + C 120
Propane C3H8 CXHY + C + H2 130
Cyclohexane C6H12 CXHY + C + H2 N/A
Dissociation Potential
Acetylene
Purity ComparisonAnalyzing trace metals,
glass mold release Welders Grade
Chemical Acetylene
Atomic Adsorption Grade Acetylene
Industrial Acetylene
Typical Assay 99.2% 99.6% 98.0%
Ammonia None 50 ppm max
Hydrogen Sulfide None Not reported
Phosphine None <20 500 ppm max
Ethylene <5,000 ppm max None
Methane <2,000 ppm max None
Ethane <500 ppm max None
Oxygen + Methane <4,000
Other Hydrocarbons <500 ppm max None
Other Contaminants None 1.95%
Acetone <1,000 ppm max Dissolved in Acetone Dissolved in Acetone
Acetylene
Today’s Acetylene
Chemical Acetylene:
• Produced as a by-product of the ethylene production process
• Higher overall purity
• More consistent in its composition
• Dissolved in dymethyl formamide (DMF), not acetone• Acetone is volatile and “carries through” with the acetylene• Acetone vapors can be a cause of sooting• Acetone can react with certain rubber compounds (valve seats, seals, etc)
• Reduces unwanted atmosphere constituents
• Highest level of reproducibility
Data provided by:Bob Esper of Praxair
Acetylene
Reactive, colorless, highly flammable gas.
Available as gas dissolved in liquid
– Through IG companies or distributors– Generally supplied in cylinders or bulk trailers– Stored in solution, under pressure– Chemical acetylene v industrial acetylene– Chemical acetylene is a co-product derived from the thermal
cracking process used to produce ethylene.
Purity Specification…
Characteristics
Acetylene
Size: 8 feet wide by 40 feet long Gross Weight (full): 80,000 pounds Configuration: 200 - 390 cf acetylene cylinders mounted with manifold Capacity: 78,000 cubic feet Pressure @ 70oF: 250 PSIG
Acetylene Bulk Trailer
Acetylene
Size: Custom designed for each application, can consist of 2 or
more bays each 10 feet wide or include cylinder banks for
uninterrupted supply. Flash Arrestor: 10,000 - 20,000 scfh capacity Pressure Regulator: Controls pressure to 15 psig Flow Rate: 1,700 - 5,700 scfh after regulator
Trailer Docking Station
Acetylene
Off Loading StationOne Trailer Bay & Back-up Cylinders
Acetylene
Off Loading StationOne Trailer Bay & Back-up Cylinders