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Introduction of oxygen and its properties : • Landfill gas contains O2 which enters the landfill as the landfill gas is withdrawn.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 : • • • • • • 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 : • • • • 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.