Oxygen Trapping in Science and Industry

Transcription

Oxygen Trapping in Science and Industry
OXYGEN TRAPPING IN
SCIENCE & INDUSTRY
Presented by :niloofar sadat fasih
Superwizer:Dr.Ghazi asgar
Today’s Overview
1
•Introduction of oxygen and its properties:
2
• Why O2 Trapping is important in science ??
3
• Reasons to remove O2 in industries??
4
5
6
•What is OXYGEN Trapping ??
• Important examples of oxygen trap
• References
Introduction of oxygen and its
properties :
• Landfill gas contains O2
which enters the landfill
as the landfill gas is
withdrawn.
• O2 may get added or
introduced in the process
of being used in gas
dryers.
Why O2 Trapping
is important in
science??
Oxygen is a column killer.
• in UHP gases, leaks allow O2 to influx
against the osmotic gradient.
• O2 can enter a gas line at any fitting.
GC needs pure N2 gas
O2 trap should be installed before the
gas line enters the Gc.
Reasons to
remove O2 in
industries??
Types of oxygen contaminated
natural gas streams
Vacuum
system
Natural gas
streams :
• landfills
• Vacuum oil
recovery systems
• Coal mine (gob
gas) methane
Tradition • May contain only
al pipeline 100 ppm of
systems
oxygen
(LPG) &(LNG)
contain some amount of O2
• LPG blending
processing with air to reduce
its calorific value and achieve
air balancing.
• Many pipeline
specifications require
natural gas to contain
less than 10 ppm of O2 .
O2 is difficult to separate from
natural gas.
• Technology not available and developed
• High cost of such a removal project
 increase corrosion in pipelines exceed
pipeline specifications
1) O2 reacts with H2S to form sulfur.
2 H2S + 3 O2
2 H20 + 2 SO2
2) O2 creates salt in acid gas removal
systems and affect the purge streams.
3) O2 cause corrosion in the steel by
handling glycol solvents used in
drying plants
Benefits of using O2 trap in purification
natural gas
Prevent degradation
of process Chemicals
decrease corrosion
in pipelines
viable
Profitable
O2 removal sys are rarely employed
& usually abandoned or blended to meet
pipeline specifications
High capital
costs
Lack of
industrial
expertise
Lack of O2
removal
system
Limited O2
removal
range
What is
OXYGEN
Trapping ??
Oxygen removal catalyst is :
A chemical used in a reaction or process
to remove O2 from gas streams like :
N2, H2, Ar
Saturated hydrocarbons
Ethylene
Propylene
And more.
Removal of oxygen from gas streams.
used for the purification of N2, Ar,CO2.
Metal catalysts
Adsorbents for
O2 Removal
Mixed-metal
catalysts
Types of O2 trappers catalysts :
 Transition metal based deoxidizer (OX-RM)
 Hydro deoxygenation catalyst (OX-HR)
 Nickel based deoxidizer (OX-RN)
Important
examples of
oxygen trap
Transition Metal Based Deoxidizer
OX-RM :
• Takes transition metal oxides as the promoter.
• Designed for gas without hydrogenation
directly
• The ineffective deoxidizer can be used through
regeneration.
OX-RM Properties :
• O2-removal active : Min15 ml O2/g deoxidizer
• Remaining O2 :Max.0.5ppm
Operation Conditions (with N2-H2 mixed gas
reduction activation before usage) :
•
•
•
•
Temperature : 200℃
Pressure : 0-6.0MPa
Feedstock gas inlet O2 content : Max4000ppm
Space velocity :0.5-3.0 hr
EX : Cu-0226 S
Contain
A copper oxide on a high surface area
alumina sphere catalyst.
Recovery Can be restored by regeneration
Removing trace quantities of O2 in inert
Application
gases at 25 ℃.( Up to 90 % )
Hydro deoxygenation Catalyst
OX-HR :
• Chemical composition :Pd-Al2O3
• Removing O2 from nitrogen, hydrogen,
and others.
Process conditions :
•
•
•
•
•
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Pressure: 0.1-10MPa
Temperature :100-210 ℃
Space velocity : 1000-2000 hr-1
Hydrogen/ Oxygen : >2 V/V
Raw material :Nitrogen oxygen
Activity index :O2 < 10ppm.
EX : ( Puristar R0-20)
Contain Robust , Pd on an alumina carrier.
Deoxo cat
Application
Removal of O2 and/or
H2 from gas streams.
Purification
of N2, Ar , and CO2.
Nickel Based Deoxidizer
OX-RN :
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•
•
•
Gases without hydrogenation directly.
Use at ambient temperature.
Deoxidation activity : ≥20 mlO2/g deoxidizer
Remaining O2 :≤0.5 ppm
Operation (with N2-H2 mixed gas
reduction activation before usage) :
•
•
•
•
•
Temperature : Room temperature to 200℃
Pressure :MPa 0~2.0
Feedstock gas inlet O2 content : Max.4000ppm
Feedstock gas inlet dew point : Max.-60℃
Space velocity :100-300(gas),0.5-3.0(liquid) hr-1
DeOxo
 Removal of O2 and/or H2 from gas
streams.
 The by-products generated at H2O and
CO2.
Regenerator
 CuO catalyst tablet
 regenerate removal of O2, CO, H2,
and other industrial gases and liquids.
Manganese (II) oxide supported
on Celite
 Reduce the O2 in N2 streams to 1 ppn
 chromatographic suitable
 Non catalytic properties
 enable to be packed directly into columns.