Steam Reforming Technology User Conference

5-7 March 2007

Bo Hartvigsen, Sales Manager, Haldor Topsoe

A/S

Challenges in Steam ReformingChallenges in Steam Reforming

Challenges in Steam ReformingChallenges in Steam Reforming

Agenda:

1. Carbon formation

2. Poisoning of catalyst (sulphur)

3. Sintering of catalyst

4. Loading

Carbon FormationCarbon Formation

C2H6 2 CO + 5 H2

2 C + 3 H2

Carbon

+H2O

Reforming

CARBON FORMATIONCARBON FORMATION

• Catalytic cracking

(on Ni crystals)• Thermal cracking

(on hot surfaces)

Two types of carbon formation:

Carbon whiskers, physical

damage of catalyst

Hot bands, NO physical

damage of catalyst

PyrolyticPyrolytic carbon (thermal cracking)carbon (thermal cracking)

Catalyst deactivation and Catalyst deactivation and

carbon formationcarbon formation

0

2

4

6

8

10

12

14

0

Ste

am

to h

igher

hydro

carb

on radio

1 2 3 4 5m from inlet

Critical

Carbon formation from higher hydrocarbons

Actual (high activity) Actual (low activity)

Carbon formation

Formation of hot bandsFormation of hot bands

CnHm CnHm

High

activity

Low

activity

CnH

m

CnH

m

CnHmCnHm

Cn H

m

Cn H

mCn H

m

CnHmCn H

m

850°C

500°C

Hot Bands in top fired reformerHot Bands in top fired reformer

Hot spots in a sideHot spots in a side--fired reformerfired reformer

Reformer design Reformer design

Radiant Wall

Topsøe

Selas

Terrace Wall

Foster Wheeler

Top Fired

MW Kellogg

KTI

UHDE

Bottom Fired

Chemico

Girdler

Risk for carbon formation is higher in a top fired reformerRisk for carbon formation is higher in a top fired reformer

HowHow to to PreventPrevent CarbonCarbon FormationFormation

1. High activity: reform higher hydrocarbons

at low temperatures

2. Use less acidic carrier

3. Promote with alkali

4. (Prereforming)

0

400 500 600 700

Catalyst Temperature

Relative Activity

Impact of Alkali Impact of Alkali

Alkali lower catalyst activity, especially at low temperatures

SulphurSulphur PoisoningPoisoning

Sulphur blocks the Nickel surface area

Nisurface + H2S ↔ S-Nisurface + H2

Temperature dependenceTemperature dependence

0.4

0.6

0.8

1

500 550 600 650 700 750 800 850 900

Temperature, °C

ppbv=10

ppbv=50

ppbv=100

Sulphur Coverage

Dynamics of poisoningDynamics of poisoning

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 20 40 60 80 100

Tube Length, %

Year 1

Year 2

Year 3

Equilibrium

Sulphur Coverage

DesorptionDesorption of of sulphursulphur

0.0

0.2

0.4

0.6

0.8

1.0

1 10 100 1000 10000

Time, hr

Sulphur Coverage

700 °°°°C 800 °°°°C

S-Nisurface + H2 ↔ Nisurface + H2S

SulphurSulphur RegenerationRegeneration

Steam SV : 4000 and T(exit): 800

900

920

940

960

980

1000

0 2 4 6 8 10Time

0

100

200

300

400

PPM SO2

TWT's

BeforeAfter

Temperat ure °° °°C

SO2

S-Nisurface + H2O → NiO + H2S

H2S + 2 H2O → SO2 + 2 H2

Regeneration for CarbonRegeneration for Carbon

Steam SV : 4000 and T(exit): 800

0

2

4

6

8 9 10 11 12

Time

%

O2

CO2

C + O2 → CO2

SinteringSintering

• Decreased C tolerance

• Decreased S tolerance

• Decreased activity

Fresh

Fresh Used

Sintering of Nickel SurfaceSintering of Nickel Surface(Ceramic Reforming Catalyst)(Ceramic Reforming Catalyst)

1

0

0.2

0.4

0.6

0.8

1.0

10 100 1000

Time/hours

RelativeNiarea

aftersinter ings/s0

550°C

700°C

800°C

Triple DeckerTriple Decker

700

750

800

850

900

0 2 4 6 8 10

Distance from Inlet, m

Temperature

TWT

Catalyst

Sulphur Carbon Sintering

RK-211 RK-201 R-67-7H

Properties of Topsoe Reforming CatalystProperties of Topsoe Reforming Catalyst

R-67-7H : Carrier: MgAl2O4 (spinel)

Ni content: 14 %

RK-201: Carrier: CaAl2O4 + MgAl2O4

Ni content: 12 %

K content: 0.4 %

RK211: As RK-201 except :

Doped with noble metal

Prereduced

Reformer loading techniquesReformer loading techniques

• Sock loading

• Unidense™

• SpiraLoad™

SpiraLoadSpiraLoad loadingloading tubetube

The The SpiraLoadSpiraLoad™™ techniquetechnique

Comparison of reformer loading Comparison of reformer loading

techniquestechniques

Time pr. tube, min

Tubes unloaded, %

Manpower

Automised

Sock loading

30-40

~ 2

Demanding

Low

Unidense™

15-20

~ 2

Normal

Low

SpiraLoad™

15-20

0.01

Normal

High

END END

CHALLENGES IN STEAM REFORMINGCHALLENGES IN STEAM REFORMING

QUESTIONS?