ASPIRE KAIST, South Korea

Transcription

1 ASPIRE KAIST, South Korea

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4 Obama s speech, 27 The G.I. Bill sent an entire generation of Americans -- including my grandfather -- to college and then on to the middle-class. Legions of scientists and engineers emerged from our race to space whose discoveries and innovations have forever changed the world. This same opportunity exists today. That's why my plan isn't just about making dirty energy expensive, it's about making clean energy affordable -- a project that will create millions of new jobs and entire new industries right here in America. Remarks of Senator Barack Obama Real Leadership for a Clean Energy Future Monday, October 8th, 27 Portsmouth, NH The G.I. Bill was an omnibus bill that provided college or vocational education for returning World War II veterans.

5 Dirty energy smart technology Fuel Woods Crops Dirty energy smart tech. Electricity Garbage Heat Coal Alcohol fuel Landfill gas Energy Sources Raw materials

6 Dirty energy smart technology Biomass Fossil fuels Coal Syngas Dirty energy smart technology : Reaction path control - Investigation of reaction mechanism and design Liquid fuels Synthetic NG Hydrogen Chemicals/ Polymers

7 Dirty energy smart technology Biomass Fossil fuels Coal Diesel reforming Syngas Liquid fuels Synthetic NG Hydrogen Chemicals/ Polymers

8 Diesel reforming technology as the first step 1. Diesel is a surrogate of dirty fuel. 2. Dirty energy is converting dirty energy (biomass, coal and tar etc.) to renewable energy by using chemical reaction processes (reforming, gasification etc.). 3. All conversion processes have some issues such as carbon deposition and are related to the same reaction mechanism: low T,P oxidation. Diesel JP-8, Tar etc. Reforming Syngas Biomass, Coal etc. Gasification Syngas

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10 Hydrocarbon Reforming External reforming Autothermal reforming Partial oxidation C 1 (NG), C 3 ~C 4 (LPG,Butane), C 5 ~C 16 (Gasoline, Diesel) C 3 ~C 4 (LPG,Butane), C 5 ~C 16 (Gasoline, Diesel) Hydrocarbon fuel reforming system Internal reforming Steam reforming Indirect reforming Direct reforming C 1 (NG), C 3 ~C 4 (LPG,Butane) C 1 (NG) Pre-Reforming C 3 ~C 4 (LPG, Butane) Autothermal Reforming : Multi fuel reforming process

11 Diesel fuel processor - Sulfur Removal - Low hydrocarbon (C 2 ~ C 4 ) Removal Liquid fuel NG & LPG Gas Cleaning Higher purity -rich gas production WGS reaction(1 st CO removal) Syngas PROX(2 nd CO removal)

12 Diesel reforming Advantages - High hydrogen density - Wide application Issues - Aromatics - Sulfur poisoning - Fuel delivery & Mixing - Carbon deposition Volumetric, gravimetric densities of hydrogen to various energy sources

13 Issues of diesel reforming Issues - Aromatics - Sulfur poisoning - Fuel delivery & Mixing - Carbon deposition Solutions - Selection of the high tolerance reforming catalyst - Desulfurization - Fuel injector(atomizer) - Low-hydrocarbons removal (Post-reforming)

14 Yield (mol/mol) Effect of Substrate in Heterogeneous Catalyst - Reforming performances of substrates SOFC Materials Reforming Catalysts CGO shows good performance as an electrolyte. Synthetic Diesel, O/C=1.25, O 2 /C=.5, 5/h O 2e - O 2-4e - O 2- O CGO YSZ PSC Al 2 O 3 Blank Anode Cathode Temp. (deg.c) Electrolyte (SOFC Mechanism ) (Screening of Support )

15 Heat Flow cor/mw Yield (mol/mol) Effect of Substrate in Heterogeneous Catalyst - Carbon Deposition Synthetic Diesel, O/C=1.25, O 2 /C=.5, GHSV=5/h 16 Yield : CGO-M1&M4 > CGO-M1 > M1/Al 2 O 3 Carbon Deposition : Al 2 O 3 -M1>CGO-M1&M4>CGO-M CGO-M1&M4 CGO-M1 6 4 Synthetic Diesel, H2O/C=1.25, O2/C=.5, 5/h. Cat. Vol.=2ml (1) Aged Al2O3-M1 (2) Aged CGO-M1& M4 (3) Aged CGO-M Temp.(deg.C) (CGO-M1&M4 vs CGO-M1) (1) (2) (3) (1) Temperature (deg.c) (Carbon Deposition) (2) (3)

16 Product (mol%, N 2 & O free) Demonstration of 2 W e self-sustaining reformer Temperature (deg. C) - Steady-state operation Diesel (GS Caltex), O/C=1.25, O 2 /C=.5, 125/h, CGO-M1=18.63 caculated on synthetic diesel base Inner Temperatures CO CO 5 Wall Temeratures 1 C2~C4 CH Time(hour) diesel air, water Distance (inch) Catalyst Zone (Product Distribution) (Reforming Temperatures at each point)

17 Carbon deposition problem - Ethylene formation Product (mol%, N 2 & O free) Ethylene formation Homogeneous reaction Synthetic Diesel, GHSV=12,5 /h, O/C=1.25, O 2 /C= Blank reactor, Conversion = 5.47 % Catalyst reactor, Conversion ~ 1 % H2 CO2 CO CH4 C2H6 C2H4 C3H8 C3H6 C2H2 Product

18 Carbon deposition problem - Ethylene concentration of several liquid fuels C2H4 (mol/mol) Fuel Conversion (%) Higher hydrocarbons & Paraffins Fuel conversion 9 ~ 1 % But, Ethylene (C 2 H 4 ) Carbon deposition Carbon precursors : Olefins (Ethylene) - Issue of carbon deposition Ethylene(C 2 H 4 ) Carbon Deposition Long-Term performance Hydrocarbon Fuels, O2/C=.5, H2O/C=1.25, 5/h, CGO-M1=2ml C 16 H 34 C 8 H 18 C C16H34 C12H26 C6H14 Temperature(deg. C) C2H4 (mol/mol).4.2. Temp. (deg.c) cyclo-c6h12 C7H8 n-c6h14 C11H1 i-c8h18 Temp. (deg.c) C 6 H 12 C 7 H 8 C 11 H 1

19 Product (mol/mol) Carbon deposition problem - Ethylene reforming ; ATR, POX condition Product (mol/mol) Conversion : ~ 1 % No degradation of reforming performance ATR Condition POX Condition 3. Ethylene = 4sccm, O/C = 1.25, O 2 /C=.7, 8 deg. C, CGO-M1, Noodle 2.5 Ethylene = 4sccm, O 2 /C=.7, 8 deg. C, CGO-M1, Noodle CO 2 CO CO 2 CO CH 4 C 2 H 6 C 2 H Time (h) Time (h)

20 Temp. (Degree C) Carbon deposition problem - Ethylene reforming ; SR condition Product (mol/mol) Temp. (Degree C) Product (mol/mol) Conversion : ~ 1 % 7 % Severe degradation of reforming performance SR Condition ( O/C = 1.25) Ethylene = 4 sccm, O/C=1.25, 8 deg. C, CGO-M1, Noodle After catalyst Temp. Before catalyst Temp. 4 2 Temp. 1 Temp. 2 CO 2 CO CH 4 C 2 H 6 C 2 H Ethylene = 4 sccm, O/C=1.25, 8 deg. C, CGO-M1, Noodle After catalyst Temp. Before catalyst Temp Time (h) 74 Temp. 1 Temp. 2 C 2 H Time (h).1.

21 Carbon deposition problem - Ethylene reforming ; SR condition Product (mol/mol) Conversion (%) O/C = 1.25 O/C = 3 No degradation of reactor performance SR Condition ( O/C = 1.25, O/C = 3) Ethylene = 4 sccm, 8 deg. C, CGO-M1, Noodle 6 SCR = 1.25 SCR = CO 2 CO CH Ethylene = 4 sccm, 8 deg. C, CGO-M1, Noodle SCR =1.25 SCR = 3 C 2 H 6 2 C 2 H Time (h) Time (h)

22 Carbon deposition problem - TPO profile mol% Total amount of coke SR ( O/C = 1.25) > SR ( O/C = 3) > POX ~ ATR O/C Carbon deposition.6 TPO, AIR=5sccm, 18 to 9 deg.c (1 deg.c/min) CGO-M1, Noodle, C 2 H 4 =4 sccm, 22h SR condition(scr=3) SR condition(scr=1.25).4 ATR condition(scr=1.25,ocr=.7).2 POX condition(ocr=.7) Temp. (deg. C)

23 Fuel Conversion (%) & CO (mol%)_ N 2, O Free Fuel Conversion (%) C 2 H 4 (mol%)_ N 2, O Free Suppression of carbon deposition - Variation of reaction condition O/C : High Fuel Conversion Higher Long-Term Performance O/C =3 : ~1 h (no regeneration) < O/C variation > Synthetic Diesel, GHSV=12,5 /h, O 2 /C=.7, 8 deg. C CGO-M1 Noodle 1 1 Synthetic Diesel, GHSV=12,5 /h, O 2 /C=.7, 8 deg. C CGO-M1 Noodle SCR = 1.25 SCR = 2 SCR = SCR=1.25 SCR=2 SCR= Time (h) Time (h)

24 Product (mol%, N 2 & O Free) Efficiency (%) Product (mol%, N 2 & O Free) Suppression of carbon deposition - Variation of reaction condition < O 2 /C variation ; O 2 /C =.8 > O 2 /C =.8 : High Fuel Conversion Long-Term Performance of ~24 h Low Hydrocarbon (Decreasing of carbon deposition) High Reforming Efficiency ~ 7% GHSV=12,5 /h, O/C=3, O 2 /C=.8, 8 deg. C, CGO-M1 Noodle 1 ml Efficiency CO 2 CO GHSV=12,5 /h, O/C=3, O 2 /C=.8, 8 deg. C, CGO-M1 Noodle 1 ml C 2 H 6 C 2 H 4 C 3 H 8 C 3 H 6 CH 4, C 2 ~C Time (h) Time (h)

25 Product (mol%, N 2 & O Free) Efficiency (%) Product (mol%, N 2 & O Free) Suppression of carbon deposition - Variation of reaction condition < O 2 /C variation ; O 2 /C = 1. > O 2 /C = 1 : High Fuel Conversion Long-Term Performance of ~12 h Low Hydrocarbon (Decreasing of carbon deposition) Reforming Efficiency ~ 4 % GHSV=12,5 /h, O/C=3, O 2 /C=1, 8 deg. C, CGO-M1 Noodle 1 ml CO 2 5 Efficiency CO CH 4, C 2 ~C GHSV=12,5 /h, O/C=3, O 2 /C=1, 8 deg. C, CGO-M1 Noodle 1 ml.1.8 C 2 H 6 C 2 H 4 C 3 H 8 C 3 H Time (h) Time (h)

26 Efficiency (%) Suppression of carbon deposition - Variation of reaction condition < O 2 /C variation ; Long-term performance > GHSV=12,5 /h, O/C=3, 8 deg. C, 8 CGO-M1 Noodle 1 ml O 2 /C : Low hydrocarbon & Reforming Efficiency O 2 /C =.8 Long-Term Performance (no regeneration for ~24 h) Avg. Efficiency 7 % OCR =.7, Synthetic Diesel OCR =.8, Commercial Diesel OCR =1, Commercial Diesel Time (h)

27 Suppression of carbon deposition - Nozzle effect Patent application (USA 11/549,359, Korea )

28 Product (mol %, N 2 & O free) Fuel Conversion (mol %, O & N 2 free) Suppression of carbon deposition - Nozzle effect Improvement of Reforming Performance 1 Ultrasonic Injector Higher Selectivity and Fuel Conversion 9 2 % No Injector 8 6 Synthetic Diesel D_ Temp. (deg C) D_CO D_CO 2 D_CH 4 (Product Distribution (mol %)) H2 Delivery Device(D_) No Device CO CO 2 CH Temperature (deg. C) Fuel Conversion (%) = X ( Fuel Conversion (%) ) fuel X fuel X fuel 1 (X fuel : fuel input, X fuel : fuel output)

29 Product(mol%, N 2 & O Free) C 2 H 4 concentration (mol/mol) Suppression of carbon deposition - Nozzle effect Synthetic diesel=2.5 l/min, No catalyst, O/C=3, O 2 /C=.7, 8 deg. C Using UI, Conversion = 64% Droplet, Conversion = 55% H2 CO2 CO CH4 C2H6 C2H4 C3H6 C2H2 Products Product distribution in homogeneous reaction < Ultrasonic Injector > Reformate gas in homogeneous reaction Using UI : Fuel conversion Concentration of low hydrocarbon Concentration of C 2 H Synthetic diesel = 2.5 l/min, No catalyst, O/C=3, O 2 /C=.7 Using UI Droplet. Temp.( o C ) : Conversion : 34% 21% 51% 56% 64% 55% 69% 61% Ethylene concentration in homogeneous reaction vs. temperature

30 Reforming efficiency (%) C 2 H 4 (mol%)_ N 2 & O free Suppression of carbon deposition - Nozzle effect ; Long-term performance (Regeneration) Diesel(&Synthetic diesel), CGO-M1 = 1 ml, GHSV=12,5 /h, 8 deg. C O 2 /C =.8, Efficiency O/C = 3, Using UI O 2 /C =.7, O/C = 1.25, Droplet C 2 H Fresh catalyst Regen. #1 Regen. #2 Time (h) Reforming efficiency & ethylene distribution as regeneration process vs. time

31 SMD ( μm ) SMD ( m) Diesel delivery and mixing SMD ( μm )= - New types of injector are under development Total Volumeof Droplets Total SurfaceAreaof Droplets (Sauter's Mean Diameter) Injector nozzle ml/min 2. ml/min 2.2 ml/min 2.5 ml/min Ultrasonic Injector Power (W) 4 3 Diesel 6 ml/min 7 ml/min 8 ml/min Type I Air flow rate (l/min) Patent (Korea)

32 Gas-phase Reactions in the Mixing Region - Advanced delivery systems help, but problem still persist Excess CO 2 produced Undesired products C 2 H 4 (a deposit precursor) formed 7% dodecane 3% -methylnaphthalene O/C=1.4 S/C= K τ=~1.5s S. Yoon, I. Kang and J. Bae, Int. J. Hydro. Ener. 34 (29) Gas-phase reactions on blank reactors

33 NTC Behavior of Surrogate Fuel Fuel conversion (%) C 2 H 4 mole fraction A potential complication is the NTC behavior of hydrocarbons in the temperature range expected in the mixing region. The NTC behavior was observed at the temperature range of 4 ~ 55 o C. Fuel conversion and ethylene yield at the residence time of 1 ms (Fuel: n-octane, O/C=1.6, S/C=1.5) Inlet temperature ( o C)

34 Residence Time-Temperature Operating Window Except n-butane, the other alkanes examined showed quite similar behavior. Similar trends are observed in terms of both conversion and ethlyene production. For most alkanes it would be better to initiate mixing at temperatures near 55 o C. Threshold residence times of alkanes (O/C=1.6, S/C=1.5) 4 3 n-butane n-hexane n-octane n-dodecane n-hexadecane 4 3 n-butane n-hexane n-octane n-dodecane n-hexadecane 5% (ms) 2 t (ms) Inlet temperature ( o C) Inlet temperature ( o C) τ 5% : the time required for 5% of fuel conversion τ t : the time required for the ethylene mole fraction to reach.1

35 Ethylene effect in the SOFC Stack Voltage (V) Stack Voltage (V) Slope : -.525%/h Time (h) Time (h) 1 Slope : -1.4%/h (a) LHV CH4 /LHV H2+CH4 = 1% (b) LHV C2H4 /LHV H2+C2H4 = 1% Degradation of short SOFC stack performance

36 Ethylene effect in the SOFC Voltage (V) Z'' (ohm cm 2 ) Z'' (ohm cm 2 ) 1.2 : O:N 2 =43:34:129 (sccm) -4-1 : O:N 2 =43:34:129 (sccm) (t < min) (t < min) C 2 H 4 : : O:N 2 =4.2:43:34:129 (sccm) (t = min) (t = 34 min) (t = 89 min) (t = 12 min) (t = 131 min) Z' (ohm cm 2 ) C 2 H 4 : : O:N 2 =4.2:43:34:129 (sccm) (t = min) (t = 32 min) (t = 87 min) (t = 99 min) (t = 554 min) Current density (A/cm2) Z' (ohm cm 2 )

37 Ethylene effect in the SOFC Conductivity (S cm -1 ) Temp. = 75 o C CH 4 :N 2 =11:189 (sccm) C 2 H 4 :N 2 =11:189 (sccm) :N 2 =2:18 (sccm) Time (min.) Solutions - Low hydrocarbon removal in reformate - Development of coke tolerant anode of SOFC

38 Mechanical failure of SOFC anode by carbon formation Intitial condition After 25 min After 25 min

39 Ethylene-induced carbon deposition 1. J.R. Rostrup-Nielsen, K. Aasberg-Petersen, Handbook of fuel cells, Ch.14(23) Ethylene > 6 C n H m Olefins Coke (C 2 H 4 ) C n-2 H z C CH x CH x + O CO, Rate of carbon formation for selected hydrocarbons [1] C 2 H 4 : Carbon precursor at reformer and SOFC Suppression of C 2 H 4 formation and C 2 H 4 Removal are required

40 Reformate gas cleaning Cleaning of Liquid fuel Reformate Gas - Sulfur removal - Low hydrocarbon (carbon precursor) removal Concept Clean Gas Reformate gas or - Sulfur Removal - Low hydrocarbon (C 2 ~ ) Removal

41 Sulfur removal - Thermodynamic analysis S (vol. ppm) S concentration(vol. ppb) Sulfur-compounds conversion C a H b S c + S + Desulfurization S + ZnO ZnS + O, H< % O 6% O % O % O % O Temperature ( o C) Temperature ( o C) Reaction of desulfurization : Exothermic reaction

42 Effect of sulfur on diesel reformer Product (mol/mol) Fuel conversion (%) S Concentration (ppmv) S conversion = ~1 % Reaction condition Synthetic diesel + C 2 H 6 S 2 1 ppm(wt) GHSV = 12,5 /h, SCR = 3, OCR =.8 GHSV = 12,5 /h, SCR = 1.25, OCR =.7 Desulfurizer : G-72D(Sud-chemie) = 6 ml, 35 deg. C 16 Before Desulfurizer 14 After Desulfurizer Synthetic diesel(c 2 H 6 S 2-1ppm), 8 deg. C, CGO-Pt.5wt.% 2 ml, O/C = 3, O 2 /C =.8 H2 CO2 CO CH4 C2~C4's Conv. Product distribution Synthetic diesel(c 2 H 6 S 2-1ppm), 8 deg. C, CGO-Pt.5wt.% 2 ml, Desulfurizer : G-72D(Sud-chemie) = 6 ml, 35 deg. C 35 Before desulfurizer 3 After desulfurizer H O/C = 3, O 2 /C =.8 O/C = 1.25, O 2 /C =.5 S concentration

43 Sulfur removal S vol. ppm S vol. ppm Adjustable Temp. : 3 ~ 5 o C Adjustable GHSV : < 2, /h Catalyst vol.(ml) GHSV in desulfurizer(/h) 1.2 ~3, 1.75 ~2, 3.5 ~1, Before desulfurizer (ATR Temp. : 8 o C) After desulfurizer 6 4 Before desulfurizer (ATR Temp. : 8 o C) After desulfurizer (Desulfurizer Temp.: 4 o C) Desulfurizer temperature (deg. C) Temperature effect Desulfurizer catalyst Vol. (ml) GHSV effect

44 Low hydrocarbons removal - Post-reforming Product (mol/mol) Product (mol/mol) Product (mol/mol) No low hydrocarbons (C 2 ~ C 4 ) after post-reformer Synthetic diesel, GHSV=12,5 /h, O/C=2, O 2 /C=.5 CGO-Pt.5wt.% Noodle 2 ml, Reforming temp. = 8 o C 18 Synthetic diesel, GHSV=12,5 /h, O/C=2, O 2 /C=.5 CGO-Pt.5wt.% Noodle 2 ml, Reforming temp. = 8 o C CO CO 2 CH 4,C 2 ~C C 2 H 4 C 2 H 6 C 3 H 8,n-C 4 C C 3 H 6 1 Diesel reforming Sampling number Sampling number Synthetic diesel, GHSV=12,5 /h, O/C=2, O 2 /C=.5 CGO-Pt.5wt.% Noodle 2 ml, Reforming temp. = 8 o C CH 4 4 CO 2 CO Diesel reforming + Low hydrocarbon removal Post-reformer temperature (deg. C)

45 Low hydrocarbons removal - Post-reforming Reforming Efficiency (%) C 2 ~ C 4 amount (mol/mol) Catalytic activity for removing low hydrocarbons in diesel reformate NECS-PR1 > NECS-PR2 > NECS-PR3 Synthetic diesel, GHSV=12,5 /h, O/C=2, O 2 /C=.5 Reforming Cat. : CGO-Pt.5wt.%, Reforming temp. = 8 o C Post-reforming Cat. : 3.5 ml Synthetic diesel, GHSV=12,5 /h, O/C=2, O 2 /C=.5 Reforming Cat. : CGO-Pt.5wt.%, Reforming temp. = 8 o C Post-reforming Cat. : 3.5 ml Post-reforming Cat. : NECS-PR1.8 Post-reforming Cat. : NECS-PR2(.5wt%) Post-reforming Cat. : NECS-PR2(3.wt%) Post-reforming Cat. : NECS-PR3(1wt%).6 Post-reforming Cat. : NECS-PR4(.5wt%) Post-reforming Cat. : NECS-PR1 Post-reforming Cat. : NECS-PR2(.5wt%) Post-reforming Cat. : NECS-PR2(3.wt%) Post-reforming Cat. : NECS-PR3(1wt%) Post-reforming Cat. : NECS-PR4(.5wt%) Post-reformer temperature (deg. C) Post-reformer temperature (deg. C)

46 Low hydrocarbons removal - Post-reforming mol% mol% Candidate catalysts for post-reforming NECS-PR1 : Ni-based Catalyst (Ni 5 wt.%) NECS-PR2 : Novel metal-based Catalyst (Novel metal 3 wt.%) Carbon tolerance : NECS-PR2 > NECS-PR TPO, AIR=5sccm, 18 to 95 deg.c (5 deg.c/min) CO2 CO 1..8 TPO, AIR=5sccm, 18 to 95 deg.c (5 deg.c/min) CO2 CO Temp. (deg. C) Temp. (deg. C)

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48 Integrated diesel fuel processing Fuel injector - Mixing effect of reactants (fuel, air, steam) Integrated Diesel fuel Processor Autothermal reforming - Effective decomposition of Aromatics - High selectivity of & CO - Suppression of carbon deposition Desulfurization - Sulfur compounds removal for post-reforming & SOFCs Post-reformer - Low-hydrocarbons(carbon precursors) removal for SOFCs

49 Integrated diesel fuel processor Diesel ATR ;Production of -rich syngas Desulfurizer ;Sulfur removal Post-reforming ;Low hydrocarbons removal Syngas Patent application (Japan ) Patent registration (Korea )

50 Integrated diesel Diesel fuel Reformer processor - kw-class diesel fuel processor Patent application (Japan ) Patent registration (Korea )

51 Integrated diesel Diesel fuel Reformer processor - kw-class diesel fuel processor

52 Temp. (deg. C) Integrated diesel fuel processor - kw-class diesel fuel processor 1 TC3 8 TC2 TC4 TC5 TC6 TC9 TC7 TC8 6 TC1 4 2 Diesel Air, Steam ATR Catalyst Bed Distance (mm)

53 Temp. (deg. C) Integrated diesel fuel processor - kw-class diesel fuel processor 6 5 TC1 TC13 TC TC11 TC ATR Reformate Desulfurization Catalyst Bed Post-reforming Catalyst Bed Distance (a.u.)

54 Integrated diesel fuel processor Integrated 1kW e -class diesel fuel processor Complete removal of low-hydrocarbons Successfully operated for about 9 hours

55 Conclusions 1. Dirty energy smart technology is converting dirty energy to renewable energy by using chemical reaction processes. 2. KAIST has derived dirty energy smart technology from diesel reforming study. 3. KAIST has been studying diesel reforming for 1 years and obtained following results. Carbon deposition is critical issue. Ethylene is a precursor of carbon deposition. New concept called post-reforming was invented to remove low hydrocarbon. Integrated diesel fuel processor was developed and operated for ~ 9 hours successfully.

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