1. Energy Efficiency and Innovative Emerging Technologies for Olefin Production
T. Ren
Utrecht University, The Netherlands
Heidelberglaan 2, 3584 CS
Sponsored 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 Institute
Sustainable Development and Transition Management

2. In this presentation Introduction to olefins
Energy use and CO2 emissions
Energy analysis
State-of-the-art
Innovations
Conclusion
Next step

3. Where is the Olefin Industry?
IPTS 2000

4. Light olefins and Steam Cracking
Ethylene (C2H4) and
Propylene (C3H6)
are two most important light olefins
They are the building blocks
of the chemical industry.
Their production process, steam cracking,
has the backbone status for the sector.

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

6. Steam Cracking
BASF 2000

7. Energy Use and Emission from Steam Cracking
Steam cracking is the single most energy consuming processes in the chemical industry
ca. 30% of the sector’s total final energy use
and ca. 180 millions tons of CO2 in 2004
Another reason for innovation:
over 35% of European crackers are over 25 years old

8. 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 of
Feedstock (wt. %)
naphtha 55,
ethane 30,
LPG 10,
gas oil 5
ethane 55,
naphtha 23,
propane15,
naphtha 75,
gas oil 9,
ethane 5
Ethylene capacity
(Million tons)
28-30
30-32 (23-24 by
Western Europe)
Propylene capacity
53-55
16-17
17-18
Total process energy
(fuel combustion and utilities
included) (EJ)
2-3
Total CO2 emission
(fuel combustion, decoking and utilities included) (Million tons)
43-45
e CO2 emission and process energy use are based on [32] and [5]. Decoking data is from [29]. US figures are lower than those of Europe due the fact that heavy feedstocks use more energy use in total.

9. Conventional Naphtha-based Steam Cracking Process
IPPC/BREF 2001

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

11. Energy/Exergy Analysis
Ethane
Naphtha
Process Energy
Exergy loss
[27]
[31]
Our
estimate
[26]
[80]
[20]
Pyrolysis
Heat of reaction
23%
65%
Fuel combustion and heat transfer to the furnace
75% (or
15 GJ/t ethylene)
73%
N/A
Steam,
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)
19%
Separation
31%
20%
De-methanization
12%
De-ethanizer and
C2 splitter
C3 splitter 2%
De-propanization/
De-butanization
10%
Ethylene refrigeration 5%
Propylene refrigeration
30%
Total process
energy use
100%
Total exergy losses
100% or 17 GJ/t ethylene
100% (only pyrolysis section)
100% (only compression and separation)

12. 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 %):
Refrigeration and C2 separation
Fractionation and compression

13. State-of-the-Art Naphtha Steam Cracking Processes
Licensors
Technip-Coflexip
ABB Lummus
Linde AG
Stone & Webster
Kellogg & Brown Root
Coil related furnace
features
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-methanizer
separation
Double
de-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 Turbine
N/a
Ca. 3 GJ/t
ethylene saved
Offered but no data
Ethylene Yield
(wt. %)
35%
34.4%
38%
SEC
(GJ/t ethylene)
(best)
or (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.

14. 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.

15. 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)
Feed
Ethane and other gas feedstock
Ethane and oxygen
Propane and oxygen
Naphtha
C4-C9 (from steam cracking, refinery, etc.)
Crude oil, refinery heavy oils, residues, atmospheric gas oil, vacuum gas oil
Olefins
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 bed
Reactors with hydrogen co feed but less steam
Fixed or fluidized bed
Riser and transfer line reactor
Catalyst
N/a
Mordenite zeolite
Zinc and calcium aluminate based
Zeolite (or various metal oxides)
Zeolite
Acidic zeolite (Lewis sites)
Temp. oC
Process energy
(SEC)i
Shockwave:
ca GJ/t ethylene/HVCs
Dow: ca GJ/t ethylene/HVCs
Uhde: ca GJ/t propylene; ca GJ/t HVCs
KRICT: ca. 19 GJ/t ethylene and ca. 10 GJ/t HVCs
Blachownia: ca GJ/t ethylene and
ca GJ/t HVCs
CPP: 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%
Current
status
Lab
Commercially available
Pilot plant
Lab and near commercialization

16. CHEEC Project by 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

17. 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 GJ/t high value chemicals of energy use by state-of-the-art naphtha steam cracking)

18. Ca. 90% chemical processes already benefits from catalysis,
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!

19. 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 $ /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?

20. Some Backup Sheets Why Do Catalytic Olefin Technologies Save Energy?
Progress of Cracking Process
Energy
Ethane, naphtha or other feedstocks
Olefins and byproducts
Activation Energy
without catalysts
with catalysts
Thermodynamic
energy requirement
Process energy required in a pyrolysis furnace
In the case of conventional steam cracking
Process energy required in a reactor
In the case of catalytic olefin technologies
Energy saving!
Ren 2003

21. Naphtha Thermal Cracking Free radicals Reorganization Ethylene
Simplified Chemical Reactions by Conventional Naphtha Cracking (or Thermal Cracking)
Thermal Cracking
Naphtha
Free radicals
Reorganization
Ethylene
Propylene

22. Simplified Chemical Reactions by Catalytic Naphtha Cracking
Thermal cracking
Naphtha
Catalytic cracking
Free radicals
Zeolite Catalysts
Carbonium ions
etc.
Reorganization
Ethylene
Propylene

23. 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

24. 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”