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CRACKED GAS APPLICATIONCRACKED GAS APPLICATION
Zeochem Molecular Sieve Zeochem Molecular Sieve
Z3-02 Z3-02
CRACKED GAS APPLICATIONCRACKED GAS APPLICATIONIntroduction - Olefin ProductionIntroduction - Olefin Production
Natural Gas
CH4 , C2H6 , C3H8
Crude Oil
Naphta , Gasoil, LPG
CRACKING PROCESSCRACKING PROCESS
FEEDSTOCKSFEEDSTOCKS
CRACKED GAS APPLICATIONCRACKED GAS APPLICATIONOlefin Production - StepsOlefin Production - Steps
Acid Gas Acid Gas RemovalRemoval
Pressurisation Pressurisation
CrackingCracking
Molecular Sieve Molecular Sieve DehydrationDehydration
Olefin SeparationOlefin Separation
CRACKED GAS APPLICATIONCRACKED GAS APPLICATIONOlefin Dehydration with Molecular Olefin Dehydration with Molecular SievesSieves Adsorption Process:
– 3A - Type molecular sieve– Temperature Swing Adsorption (TSA)– Reactive components in stream ( , C
C ) Conditions:
– Temp. 5 - 15°C– Pressure 20 - 30 bar– Regen.Temp. 230°C– Regen. Gas Dry, low Olefin content
CRACKED GAS APPLICATIONCRACKED GAS APPLICATIONOlefin Dehydration with Molecular Olefin Dehydration with Molecular SievesSieves Process Design
– according to cracker process– long cycle times Reduced Regen.
Cycles– high water adsorption capacity– smooth regeneration– low P
Product Gas Quality– < 1ppm moisture or DP < -100°C
Cracked Gas DehydrationCracked Gas DehydrationZeolite as Molecular Sieve Zeolite as Molecular Sieve
Alumino-silicate Na2O.Al2O3.SiO2.xH2O
microcristalline structure
A-Types :– 3A (K- Form): 0.3 nm pores
– 4A ( Na-Form): 0.4 nm pores– 5A ( Ca-Form): 0.5 nm pores
13X- Type:– 0.8 nm pores (Na-form)
Cracked Gas DehydrationCracked Gas DehydrationMolecular Sieving Effect Molecular Sieving Effect
Sieving Effect based on: molecule size or diameter
– molecules with D<0.3nm can be adsorbed in a 3A Sieve : i.e. H20, NH3, H2, He
– molecules with D < 0. 4 nm can be adsorbed in a 4A Sieve: i.e. H2O, CO2, H2S, C2H6, C2H4
polarity of the molecules– Increased affinity with increasing polarity– H20 > RSH > H2S > C2H4 > CO2
Cracked Gas DehydrationCracked Gas DehydrationZZeolite Manufacturing Processeolite Manufacturing Process
Al(OH)3 NaOH
NaHSiO3
H2O, KCl
3A-Pulver3A-Pulver
Bead Formation
Binding Clay
Activation Z3-02Z3-02
* Quality Control* Quality Control**
* *
**
** **
**
Cracked Gas DehydrationCracked Gas DehydrationQuality Control of Molecular Sieve Quality Control of Molecular Sieve Z3-02Z3-02
Characterisation– residual water content– CO2 adsorption
capacity– T MeOH– crystallinity ( X-ray
diffraction)– SEM– bulk density: 750– elemental analysis– under- & oversize
Stability– attrition– freeze thaw test– boiling water test– crush strength
Process parameter– kinetic
measurement (MTZ, Hiden)
Cracked Gas DehydrationCracked Gas DehydrationKinetic Comparison, HidenKinetic Comparison, Hiden
02468
101214161820
0 50 100 150 200 250[min]
[%w
w]
Competitive Type 3A, 1/8" extr.:120 min.: 13.4 %
ZEOCHEM Z3-02, 2-3 mm beads120 min: 14.2 %
Cracked Gas DehydrationCracked Gas DehydrationKey Properties of Molecular Sieve Key Properties of Molecular Sieve Z3-02Z3-02
High water adsorption capacity Low pressure drop (P) Good thermal and hydrothermal stability Low coke formation High freeze - thaw resistance High density
Cracked Gas DehydrationCracked Gas DehydrationDesign and Field Decay Curves for Design and Field Decay Curves for Z3-02Z3-02
5
10
15
20
0 50 100 150 200 250 300 350 400Number Of Cycles
Cap
acity
W
t %
Field
Design
Cracked Gas DehydrationCracked Gas DehydrationKey Properties of Molecular Sieve Key Properties of Molecular Sieve Z3-02Z3-02
High Water Adsorption Capacity High Water Adsorption Capacity
and Good Hydrothermal Stabilityand Good Hydrothermal Stability
• lower heat energy requirement• longer cycle times resp. less cycles • slower capacity decay• long life time characteristics
Cracked Gas DehydrationCracked Gas DehydrationZeochem / Competition Zeochem / Competition - - Field Decay Field Decay CurvesCurves
Ethylen Plant - Petromont - Varennes, Quebec
40
45
50
55
60
65
70
75
0 20 40 60 80 100 120
Cycle Number
Cycl
e Ti
me
(h)
Cracked Gas Dryer Molecular Sieve Continuing Performance
Zeochem Z3-02 in bed A installed July 7, 1995
Zeochem Z3-02 in Bed B installed June 23, 1994
Competitive Type 3A in Bed A Discharged after 23.5 months
Cracked Gas DehydrationCracked Gas DehydrationKey Properties of Molecular Sieve Key Properties of Molecular Sieve Z3-02Z3-02
Low Catalytic Binder Activity andControlled Formulation in Production
Low coke formation• high lifetime• high adsorption performance• Unsaturates and by-products remain outside pores
Cracked Gas DehydrationCracked Gas Dehydration Pressure Drop calculationPressure Drop calculation
Modification of Ergun EquationModification of Ergun Equation
PP//LL = A = AUUV V + B+ BRRVV22
psipsi viscosity (cP) viscosity (cP) gas gas density (lb/ftdensity (lb/ft33))
Bed height (ft) Bed height (ft) fluid fluid velocity (ft/minvelocity (ft/min)Particle size A B
2.5-5 mm or 4x8 US mesh 0.056 8.89 10-5
2-3 mm or 9x16 US mesh 0.156 1.36 10-4
1-2 mm or 8x12 US mesh 0.352 2.07 10-4
1/ 8“ pellet (extrudate) 0.0732 1.24 10-4
1/ 16“ pellet (extrudate) 0.238 2.01 10-4
Cracked Gas DehydrationCracked Gas DehydrationPressure Drop Field DataPressure Drop Field Data
Ethylene Plant North America
100.0
150.0
200.0
250.0
300.0
350.0
6.11
11.1
119
.11
22.1
125
.11
28.1
11.
124.
127.
12
10.1
213
.12
16.1
221
.12
25.1
231
.12 3.
16.
1
Date
Pressure drop (mbar)
270 mbar
210 mbar
Competitive Pellets
Zeochem Beads Z3-02
Pressure Drop Comparison - 3 Beds Parallel
Cracked Gas DehydrationCracked Gas DehydrationPressure Drop ComparisonPressure Drop Comparison
Lower P (Beads instead of extrudates)
• lower compression costs (- 20...25%)• allows higher flow rates
Cracked Gas DehydrationCracked Gas DehydrationPhysical Stability ComparisonPhysical Stability Comparison
max. 3.0max. 3.0
max. 3.0max. 3.0------
>90>90
Freeze-Thaw Freeze-Thaw TestTest
ChipsChips
Broken BeadsBroken Beads
max. 50max. 50524524Dust Index Dust Index (Heubach) (Heubach) ppmppm
750 750 +/-+/- 20 20660660Bulk DensityBulk Density
ISO 787 ISO 787 g/Lg/L
Zeochem Z3-02Zeochem Z3-02
2.5-5 mm Beads2.5-5 mm BeadsCompetitive Type Competitive Type 3A3A
1/8" Extrudates1/8" Extrudates
Cracked Gas DehydrationCracked Gas DehydrationKey Properties of Molecular Sieve Key Properties of Molecular Sieve Z3-02Z3-02
Physical Stability through FREEZE-THAW Resistance
• Pressure reduction during regeneration causes large temperature reduction
• Ice formation causes bead expansion• Freeze-thaw test simulates bead
expansion forces
Cracked Gas DehydrationCracked Gas Dehydration COST COMPARISON Z3-02 BEADS VERSUS COST COMPARISON Z3-02 BEADS VERSUS EXTRUDATESEXTRUDATES
BASIS: Typical Heat Cost 6.83 US$ per MWh, Typical Compression Cost
2.42 US$ / mbar / 1000 Nm3/hr per year. Same volume per column
Cracked Gas DehydrationCracked Gas DehydrationOperating CostsOperating Costs
BasisBasis Two Beds Initial 72 hour adsorption time Flow Rate 150'000 Nm3/h Temperature 12°C Pressure 20 bara Molecular Weight 23
Regeneration Time 12 hours heat at 230°C Service Lifetime 4 years
Molecular Sieve / BedMolecular Sieve / Bed 52 cubic meters52 cubic metersAdsorption timeAdsorption time 72 hours initial72 hours initial 60 hours at the end of year 1 (66 cycles) 48 hours at the end of year 2 (81 cycles)36 hours at the end of year 3 (105 cycles)
24 hours at the end of year 4 (146 cycles)
Cracked Gas DehydrationCracked Gas DehydrationComparison Z3-02 Beads / ExtrudatesComparison Z3-02 Beads / Extrudates
Adsorbent Type / Parameters
Zeochem Z3-02 Beads Split Bed
Typical 3A 1/8“ Extrudate
Pressure Drop mbar 240 310 Regeneration heat KWh 2’400 2’400 COST SUMMARY US$ per year
Press. Drop cost over 4 year 348’480 450’120 Heating cost Year 1 38’970 43’300 Year 2 47’790 53’100 Year 3 62’010 68’900 Year 4 87’390 97’100 Total Costs US $ 584’640 712’520
Savings US $ 127’880
POLYMER GRADEPOLYMER GRADEOLEFIN TREATMENTOLEFIN TREATMENT
Molecular Sieve Z3-02 and Z10-03Molecular Sieve Z3-02 and Z10-03
POLYMER GRADE OLEFINSPOLYMER GRADE OLEFINSPre- PurificationPre- Purification
Polymerisation catalysts are very sensitive to impurities.
Zeochem recommends either Z10-03:
Dehydration plus oxygenates & sulphur compounds removal, or
Z3-02: in combination with Selexsorb* COS to remove
oxygenates, sulphur compounds, COS
* trade name of Alcoa Inc
POLYMER GRADE OLEFINSPOLYMER GRADE OLEFINS ADVANTAGES OF ZEOCHEM Z10-03ADVANTAGES OF ZEOCHEM Z10-03
Selective for removal of moisture oxygenates, carbon dioxide, sulphur compounds (H2S, mercaptans)
Outlet concentrations < 0.1 ppm Good flow distribution Long Life Excellent mechanical properties
POLYMER GRADE OLEFINSPOLYMER GRADE OLEFINSPre-PurificationPre-Purification
Alternative technology uses Z3-02 for dehydration in a dual bed system with Selexsorb* COS
Selexsorb* COS removes oxygenates and sulphur compounds including carbonyl sulphide prior to dehydration
* trade name of Alcoa Inc
Cracked Gas Cracked Gas DehydrationDehydrationSummarySummary High Quality Products Zeochem Z3-02 and
Z10-02 Technical Service including:
Design Engineering Start up with Loading Instruction Process Assistance with Follow –up Highly qualified Laboratory for investigations
set the foundations for reliability and top Performance