Environmental Engineering Reference
In-Depth Information
table .
Case study using the xl insurance database: single-walled Carbon
nanotubes (swnt) [, ]
Risk analysis step
analysis
1..Identify.process.and.materials
HiPco.process.of.gas-phase.chemical-
vapor-deposition;.process.currently.in.
commercial.use.
2...Characterize.materials.
and.processes
A...Collect.and.characterize.
data.on.material.
properties
Data.compiled.for.carbon.monoxide,.
sodium.hydroxide,.iron.pentacarbonyl,.
carbon.dioxide,.water.
B...Deine.manufacturing.
processes,.identify.
characteristics.that.
determine.risks
1..Introduce.Fe(CO)
5
.catalyst.into.injector.
low.via.pressurized.CO.
2...Heat.catalyst.stream.and.mix.with.CO.in.
graphite.heater..Fe(CO)
5
.decomposes.to.
Fe.clusters..Standard.running.conditions.
450.psi.CO.pressure,.1050°C.
3...C.atoms.coat.and.dissolve.around.the.Fe.
clusters,.forming.nanotubes..Running.
conditions.maintained.24-72.hours.
4...Gas.low.carries.SWNTs.and.Fe.particles.
out.of.the.reactor..SWNTs.condense.on.
ilters..CO.passes.through.NaOH.
absorbtion.beds.to.remove.CO
2
.and.H
2
O,.
then.recycled.
3...Determine.relative.
risk
A..Qualitative.Assessment
No.materials.present.very.high.risk.
according.to.this.model..Materials.with.
relatively.high.risk:.carbon.monoxide.
(emissions),.iron.pentacarbonyl.
(emissions).sodium.hydroxide.(toxicity,.
solubility),.carbon.dioxide.(solubility,.
emissions).
B...XL.Insurance..
Database..
Methodology
See.summary.of.results.in.Figure.11.2.
