Energy Efficiency and Innovative Emerging Technologies for Olefin Production

T. Ren

Utrecht University, The Netherlands

Email: t.ren@chem.uu.nl, Heidelberglaan 2, 3584 CSSponsored by Utrecht Energy Research Center (UCE) and

Energy Research Foundation (ECN)

European Conference on Energy Efficiency

in IPPC-Installations

On October 21-22, 2004 in Vienna, Austria

Copernicus InstituteSustainable Development and Transition Management

In this presentation

• Introduction to olefins• Energy use and CO2 emissions• Energy analysis• State-of-the-art• Innovations• Conclusion• Next step

Where is the Olefin Industry?

IPTS 2000

Light olefins and Steam Cracking

Ethylene (C2H4) andPropylene (C3H6)

are two most important light olefins

They are the building blocksof the chemical industry.

Their production process, steam cracking,has the backbone status for the sector.

Used in the production of plastics, fibers, lubricants, films,textiles, pharmaceuticals, etc. ---even chewing gum!

Steam Cracking

BASF 2000

Energy Use and Emissionfrom Steam Cracking

• Steam cracking is the single most energy consuming processes in the chemical industry

ca. 30% of the sector’s total final energy useand ca. 180 millions tons of CO2 in 2004

Another reason for innovation:

over 35% of European crackers are over 25 years old

Estimated Global Energy Use and Emission 2004

 World US

Europe (including new EU member states and FSU)

Total feedstock (Million tons)

300 85 90

Breakdown ofFeedstock (wt. %)

naphtha 55,ethane 30,LPG 10,gas oil 5

ethane 55,naphtha 23,propane15,

gas oil 5

naphtha 75,LPG 10,gas oil 9,ethane 5

Ethylene capacity (Million tons)

110-113 28-3030-32 (23-24 byWestern Europe)

Propylene capacity(Million tons)

53-55 16-17 17-18

Total process energy(fuel combustion and

utilitiesincluded) (EJ)

2-3 0.5-0.6 0.7-0.8

Total CO2 emission

(fuel combustion, decoking and utilities included)

(Million tons)

180-200 43-45 53-55

Conventional Naphtha-based Steam Cracking Process

IPPC/BREF 2001

A naphtha steam cracker (900 kt/a) at Shell Moerdijk, the Netherlands

Shell 2003

Energy/Exergy Analysis

 

Ethane Naphtha

Process Energy

Process Energy 

Exergy loss

[27] [31]   Ourestimate

[26][80][20]

Pyrolysis

Heat of reaction

23%65%

Fuel combustion and heat transfer to

the furnace75% (or 15 GJ/t

ethylene)

73%

N/ASteam,heating &losses

24%Heat exchange with

steam, TLEs and heat loss to flue gas

27%

Fractionation and Compression

22% 15% Fractionationf and Compression

25% (2 GJ/t

ethylene in

compression and the

rest of separation processes)

N/A

19%

Separation 31% 20%

De-methanization12%

De-ethanizer andC2 splitter

23%

C3 splitter2%

De-propanization/De-butanization

10%

Ethylene refrigeration

5%

Propylene refrigeration

30%

Total processenergy use

100% 100% Total exergy losses100% or 17 GJ/t ethylene

100% (only pyrolysis section)

100% (only compression

and separation)

Conclusions from Energy Analysis

• Pyrolysis section is the most energy consuming section (65% of the total energy use and 75% the total exergy losses)

• Also energy consuming (each ca. 15-20%):– Refrigeration and C2 separation– Fractionation and compression

State-of-the-Art Naphtha Steam Cracking Processes

Licensors Technip-Coflexip ABB Lummus Linde AG Stone & Webster Kellogg & Brown Root

Coil related furnacefeatures

Radiant coils pretreated to reduce coking with a sulfur-

silica mixture

Double pass radiant coil design; online decoking reduces

emissions

Twin-radiant-cell design (single split) is 13m (shorter than the average length

25m)

Twin-radiant-cell design and quadra-

cracking

Coil design (straight, small diameter), low

reaction time; very high severity

De-methanizerseparation

features

Doublede-methanizing stripping system

De-methanizer with low refrigeration

demand

Front-end de-methanizer and hydrogenation

De-methanization simultaneous mass transfer and heat

transfer

Absorption-based demethanization system

with front-end design

Gas TurbineN/a

Ca. 3 GJ/tethylene saved

N/a Offered but no data N/a

Ethylene Yield

(wt. %)35% 34.4% 35% N/a 38%

SEC(GJ/t

ethylene)

18.8-20 (best)or 21.6-25.2 (typical)

18 (with gas turbine);21 (typical)

21 (best) 20-25 No data

Conclusion: 20% of energy savings on the current energy use(25-30 GJ/t ethylene) of naphtha steam cracking are possible.

Advanced naphtha steam cracking

• Advanced furnace materials (e.g. low coking coating)

• Vacuum Swing Adsorption, mechanical vapor recompression

• Advanced distillation columns, membrane and combined refrigeration systems

• Conclusion: up to 20% energy savings are possible in the pyrolysis section and up to 15% energy savings are possible in the compression and separation sections.

Innovative Olefin Technologies

Gas Stream Technologies

Ethane Oxidative De-hydrogenation

Propane Oxidative

dehydrogenation

Catalytic cracking of

naphtha

Hydro-pyrolysis of

Naphtha

Byproduct upgrading(C4-9)

Catalytic Pyrolysis Process (CPP)

FeedEthane and other gas feedstock

Ethane and oxygen

Propane and oxygen

Naphtha Naphtha C4-C9 (from steam cracking, refinery, etc.)

Crude oil, refinery heavy oils, residues, atmospheric gas oil,

vacuum gas oil

Olefins Ethylene Ethylene PropyleneEthylene/propylene

Ethylene Propylene Ethylene/propylene

Reactor

Shockwave, combustion

gas; shift syngas;

plasma; etc.

Alloy Catalyst Reactor with

hydrogen co feed

Both a stem reformer and an

(oxy-reactor); or, cyclic fixed-bed

Fluidized bedReactors with hydrogen co feed but less

steam

Fixed or fluidized bedRiser and transfer line

reactor

CatalystN/a Mordenite zeolite

Zinc and calcium aluminate based

Zeolite (or various metal oxides)

N/a ZeoliteAcidic zeolite (Lewis

sites)

Temp. oC

625-700 900-1100 550-600 650-680 785-825 580-650 650-750

Process energy(SEC)i

Shockwave:ca. 8-10 GJ/t

ethylene/HVCs

Dow: ca. 10-12 GJ/t

ethylene/HVCs

Uhde: ca. 8-10 GJ/t propylene;

ca. 8-10 GJ/t HVCs

KRICT: ca. 19 GJ/t ethylene and ca. 10

GJ/t HVCs

Blachownia: ca. 16-20 GJ/t

ethylene andca. 10-13 GJ/t

HVCs

N/aCPP: ca. 35 GJ/t

ethylene and ca. 12 GJ/t HVCs

Yield (wt. %)j

Shockwave: highest

ethylene yield ca. 90%

Dow: final ethylene ca. 53%

if weighted against

ethane and oxygen

Uhde: propylene final yield ca.

78% if weighted against propane

and oxygen

KRICT: ethylene 38%, propylene

17-20%, aromatics 30% and HVCs

73%

Blachownia: Ethylene yield 36-40% and HVCs yield

70%

UOP: total propylene yield from steam

cracking is 30% and HVCs yield 85%

CPP: ethylene 21%, propylene 18%, C4

11%, aromatics 15% and

HVCs yield 60%

Currentstatus Lab Lab

Commercially available

Pilot plantCommercially

availableCommercially available

Lab and near commercialization

CHEEC Projectby Dow and SABIC (NL)

• CHEEC (Cheap Energy Efficient Ethylene Cracking)—catalytic olefin technology!

• Yield of ethylene and propylene together up by 24%

• Energy use reduced by 20%

• Investment lowered by 27% and variable costs lowered by 14%

Novem 2003

Conclusions from Innovative Olefin Technologies

• Catalytic olefin technologies produce high yield of valuable chemicals (in particular) propylene from low-cost feedstocks at lower reaction temperature

• Special reactors, catalysts or additional materials (oxygen, hydrogen, etc.) can be applied to reduce energy consumption

• Up to ca. 20% energy savings are possible (on 11-14 GJ/t high value chemicals of energy use by state-of-the-art naphtha steam cracking)

Overall Conclusions

• Pyrolysis section is the most energy consuming in a steam cracker

• Plenty of room for energy savings is possible in steam cracking

• Catalytic olefin technologies can lead to energy saving (up to 20%) on energy use by state-of-the-art steam cracking

Ca. 90% chemical processes already benefits from catalysis,so can steam cracking!

Our Next Step

• Energy and economic analysis for Natural gas-to-Olefin technologies have been completed—one conclusion is that at this moment there are no energy saving (75% more energy use and only feasible in locations where prices of natural gas are very low $0.75-1.0/GJ)

• Barriers/drivers and their implications for innovation in the (bulk) chemical industry are being studied

• Policies and strategies for stimulating innovation will be recommended

Thank you! Questions?

Some Backup SheetsWhy Do Catalytic Olefin Technologies Save Energy?

Progress of Cracking Process

Energ

y

Ethane, naphtha or other feedstocks

Olefins and byproducts

Activation Energywithout catalysts

Activation Energywith catalysts

Thermodynamicenergy requirement

Process energy required in a pyrolysis furnaceIn the case of conventional steam cracking

Process energy required in a reactorIn the case of catalytic olefin technologies

Energy saving!Ren 2003

Thermal Cracking

Naphtha

Free radicals

Reorganization

Ethylene Propylene

Simplified Chemical Reactions by ConventionalNaphtha Cracking (or Thermal Cracking)

Thermal cracking

Naphtha

Catalytic cracking

Free radicals

Zeolite Catalysts

Carbonium ions

etc.etc.

Reorganization

Ethylene Propylene

Simplified Chemical Reactions byCatalytic Naphtha Cracking

Drivers/Barriers (1/2)

• Economic Drivers

• Lower energy costs• Value added (from

low-cost feedstock to high value chemicals)

• Strong propylene demand

• Economic Barriers

• New plant investment in the range of 500 million to 1 billion euros

• Most old plants run with zero depreciation, low margins and over-capacity

Drivers/Barriers (2/2)

• Technical Drivers

• Rapid advances in R&D on new catalysts

• Spillover from extensive technical experience in refinery catalysts

• Technical Barriers

• Low olefin yield and high byproduct yield

• Reaction and oxygen use

• Coking and “spent catalysts”