SUSTAINABLE MATERIALS
WITH BOTH EYES OPEN
JULIAN M ALLWOOD
Steel, aluminium and climate change
Focus on CO
2• IPCC says it’s urgent • Steel and aluminium
have a big impact but not receiving much attention
Key challenges
• Scale • Uncertainty • Estimates Buildings 31% Other 7% Transport 27% Industry 35% Energy/ process emissions 28 GtCO2Other
45%
Aluminium
Paper
Cement
19%
Steel
25%
Industrial
carbon
emissions
10 GtCO
2Steel
1,040 Mt
Aluminium
45 Mt
Steel and aluminium in use
Cars and light trucks 93 Mt 9 % Trucks and ships 28 Mt 3 % Infrastructure 150 Mt 14 % Metal goods 134 Mt 12 % Domestic appliances 29 Mt 3 % Electrical equipment 27 Mt 3 % Mechanical equipment 137 Mt 13 % packagingConsumer 9 Mt 1 % Buildings 433 Mt 42 % Image: Jaguar Cars 8 Mt 18 % Trucks 3 Mt 7 % Other transport 1 Mt 2 % Other products 4 Mt 9 % Packaging 6 Mt 13 % Appliances 3 Mt 7 % Buildings 11 Mt 24 % Electrical equipment 2 Mt 4 % Electrical cable 4 Mt 9 % Mechanical equipment 3 Mt 7 %
Demand for steel and aluminium
Challenge
Over the next 40 years we expect demand
to double, but must halve our CO2 emissions
Production stabilises ... stocks stabilise ... so we can forecast demand
Approach
Forecast flows, anticipate emissions factors, predict business shape
0 3000 1500 Mt/yr 1960 2005 2050 Secondary production Primary production 0 16 8 St ock (t onnes/person) 1900 2000 2100 US France Japan Canada China India UK 0 4 12 8 St ock (t onnes/person) 2000 1975 1950 1900 2000 2000 1975 1950 1950 1900 1900 0 10,000 20,000 30,000 GDP ($/person/year) 0 250 1000 750 500 Pr oduc tion (kg/person/y ear) 1900 1925 1950 1975 2000
Global flows of steel
Messages
• 1/4 of liquid steel never reaches
products but is scrapped in production • end-of-life scrap is less than half of the scrap input Blast furnace
Steelmaking Casting Rolling / Forming Fabrication End-use products
Reduction Forming scrap Fabrication scrap Cast iron scrap Iron ore Direct reduction Oxygen
blown furnace Continuouscasting (slab)
Continuous casting (billet)
Continuous casting (bloom) Ingot Primary mill
Hot
strip mill Cold rolling mill Cold rolled coil
End-of-life scrap Electrical strip Cladding Infrastructure Reinforcing Structural Electrical Mechanical Cars Trucks Other Other Appliances Packaging Construction Industrial equipment Vehicles Metal products Hot rolled coil
CRC coated CRC galv.
HRC galv.
Reinforcing bar Wire rod Hot rolled bar Seamless tube
Heavy section Light sectionRail section Cast steel Cast iron Welded pipe HR narrow strip Plate Tin plated Plate mill Rod and bar mill Section mill
Steel product casting Iron foundry casting Electric furnace Scrap preparation Open hearth furnace Global demand in 2008 for steel products = 1,040 million tonnes
Process energy analysis — steel
• Process energy data is commercially
sensitive and incomplete • Energy for producing liquid metal dominates for both metals
Images: worldsteel Blast furnace 16 EJ 7 % Direct reduction 0.7 EJ Steel (overall) Energy = 38 EJ Electricity = 39 % Basic oxygen furnace 0.2 EJ Continuous casting 0.4 EJ 74 % Rolling 3.6 EJ 46 % Fabrication 6-11 EJ 70 % Shape casting 2.1 EJ 46 % Coating 0.6 EJ 46 % Forming 0.2 EJ 82% Electric arc furnace 2.7 EJ 86 %
Global flows of aluminium
Messages
• 40% of liquid metal never reaches
products but is scrapped in production • Aluminium recycling mainly leads to casting alloys for engine blocks Alumina
Electrolysis / Melting Casting Rolling / Forming / Casting Fabrication End-use products
Electrolysis
Remelting
Refining
Casting
Casting Shape casting
Hot rolling Cold rolling Foil rolling
Cold rolled sheet
Fabrication scrap End-of-life scrap Forming scrap Forming scrap
Fabrication scrap Infrastructure
Structural Non-structural Cable Electrical Mechanical Cars Other Other Durables Packaging foil Drinks cans Construction Industrial equipment Vehicles Metal products Plate Foil
Hot rolled strip
Die castings Other Sand castings Permanent castings Cable / wire Extrusions Extrusion Wire drawing Global demand in 2007 for aluminium products
Process energy analysis — aluminium
• Process energy data is commercially
sensitive and incomplete • Energy for producing liquid metal dominates for both metals
Electrolysis 5.0 EJ 100 % Alumina mining +refining 1.1 EJ 2 % Ingot casting 0.05 EJ 44 % Alloy ingot casting 0.03 EJ 44 % Scrap refining 0.15 EJ 14 % Scrap remelting 0.04 EJ 30 % Shape casting 0.17 EJ 1 % Fabrication 0.3-0.6 EJ 70 % Rolling 0.23 EJ 72 % Extrusion +drawing 0.09 EJ 19 % Aluminium (overall) Energy = 7.6 EJ Electricity = 76 %
Business
structure
Landowners Consumers Government NGOs Lobby groups Trade associations Insurance providers UniversitiesFinancial services merchantsScrap
Mining industry Refiners Steel+ aluminium industries Fabricators Stockholders Construction Industrial equipment Metal products Vehicles Demolition companies Estate agents Utility companies Developers Planners Surveyors Architects Building engineers Contractors +tradesmen Equipment manufacturers Part suppliers Industrial equipment users Maintenance providers Factory designers Retailers Appliance manufacturers Food industry Fillers Packaging manufacturers Consumer goods industry Ship builders Energy providers Aircraft manufacturers Airlines Car + truck manufacturers Logistics companies Maintenance providers Dealers Leasing companies
Food and drink Mining and minerals Steel Aluminium Metal products Transport goods Machinery and equipment Other manufacturing Utilities Construction Transport services Other business and public services
Food and drink Mining and minerals Steel Aluminium Metal products Transport goods Machinery and equipment Other manufacturing Utilities Construction Transport services Other business and public services
The story so far ...
The world of steel and aluminium
• Demand is likely to double but we want to halve emissions in 40 years • Recycling rates are already high
• Most energy is used in upstream liquid metal production
• The cost of these metals is a small fraction of the price of final goods • Forecasting depends on future flows and future emissions factors
Looking ahead ‘with one eye open’ — emissions factors
• The easiest solution for everyone is to reduce emissions factors • Is it possible to reduce them by 75%?
Looking ahead ‘with both eyes open’ — metal flows
With one eye open — energy efficiency?
Coke 26% Gas 6.5% Ferrous raw materials 40% Other 24% Electricity 3.6% Steel production costs Energy 35% Other 3% Alumina 25% Labour +other materials 37% Aluminium production costsAbout one third of the cost of producing both metals is to purchase energy ... as a result both industries already seek every possible energy efficiency - and both are within sights of Gibbs’ theoretical limit 0 15 60 45 30 GJ/t crude st eel 1975 2009 Theoretical minimum = 6.6 GJ/t Best practice = 12.5 GJ/t Average 4 0 12 MW h/t aluminium 1980 2009 8 16 Theoretical minimum = 9 MWh/t Average Best practice = 13 MWh/t
With one eye open — heat capture?
Temper atur e (ºC ) 0 450 900 1350 1800 Time Casting Hot w or k Heat tr eatment Primary processes Rebar Car bodyForged mining part Chassis plate Wire Hot rolling Electricity generation Losses Primary energy Hot metal Casting ESP Electricity generation Losses Primary energy Hot metal
• We could cut out heating cycles, but • Heat capture from hot gases is
With one eye open — new process routes?
Used gas Gas scrubber Gas scrubber Used gas Cool clean gasIron ore pellets
Directly reduced iron ready for the electric arc furance Reformer Natural gas Reformed gas Oxygen Melting cyclone Off gas duct Smelting reduction vessel
Molten oxide + electrolyte
St eel shell Metal pool Current feed Collector bar -+ Anode Anode Cell floor Frozen electrolyte Oxygen gas bubbles Liquid cathode Cell sidewall
Point feeders break crust and introduce metal oxide here
-+ + -Aluminium Pool Off gas Aluminium Vapour
recovery Vapourrecovery
Alumina and carbon feed
Direct reduced iron (to EAF)
Multipolar
electrolysis cell anodesInert Carbothermic reduction
Smelt reduction
+ CCS pyroelectrolysisIron ore
Aluminium
With one eye open — clean electricity?
1.25 W/m2 0.2 W/m2 0.3 W/m2
With one eye open — carbon capture + storage
Infinite potential provided someone else pays for it ...
• The novel steel routes require electricity or storage
• There won’t be enough ‘renewable’ electricity - so nuclear or fossil and storage • Globally there are 3 small test sites in operation - yet the IEA is
forecasting up to 25% of all emissions will be stored within 40 years
2
1 5
3
4
1. Depleted oil and gas reservoirs 2. Use of CO2 in enhanced oil recovery
3. Deep unused saline water-saturated reservoir rocks 4. Deep unmineable coal seams
5. Use of CO2 in enhanced coal bed methane recovery
With one eye open — scenarios
With one eye open
• Both industries are already motivated to pursue energy efficiency - there are very few options left
• Ideas for innovation depend either on ‘clean electricity’ or carbon storage, or both - and are a long way from widespread use
• Even with the most optimistic projections, we cannot possibly halve emissions by 2050 if demand doubles
Aluminium
Steel
0 1 2 3 4 5
Gt CO2
BAU Process Efficiency Options
6 Target Current (2008) 0 0.3 0.6 0.9 1.2 1.5 Gt CO2 BAU Process Efficiency Options
Current (2007)
1.8 Target
With both eyes open — what else can we do?
Alumina
Electrolysis / Melting Casting Rolling / Forming / Casting Fabrication End-use products
Electrolysis Aluminium Aluminium Remelting Aluminium Refining Casting
Casting Shape casting
Slab Billet
Alloy ingot
Hot rolling Cold rolling Foil rolling
Cold rolled sheet
Fabrication scrap End-of-life scrap Forming scrap Forming scrap
Fabrication scrap Infrastructure
Non-structural in buildings Electrical cable Mechanical Cars Other Other Consumer durables Packaging foil Drinks cans Industrial equipment Vehicles Metal products Plate Foil
Hot rolled strip
Die castings
Other Sand castings Permanent mould castings Cable / wire Extrusions Extrusion
Wire drawing
Global demand in 2007 for aluminium products
= 45 million tonnes
Re-use
old metal Divert scrap
Reduce yield loss
Use less
by design life goodsLonger
Reduce demand
With both eyes open — use less by design
5 principles of lightweight design
1. Support multiple loads together 2. Don’t over-specify the loads 3. Align loads with members to avoid bending 4. Optimise the cross-section for bending 5. Choose the best material
Barriers
Loads before use Asymmetric risks Manufacturing
Opportunities
Other supports Rewrite standards New processes α1 α2We scrap more than a
quarter of our liquid metal
• Blanking, trimming and machining are the main causes
• Additive manufacture does not provide a solution
• Novel forming processes are required combined with casting to make
intermediate products closer to final shapes
With both eyes open — reduce yield losses
0 100% 50% I-beam Steel Aluminium
Car doors Drinks
can Wingskin
0 10 20
Cumulative Yield (t output/t liquid steel)
Cu m ula tiv e p ro ce ss en er gy (G J/t liq uid st ee l) 0 0.2 0.4 0.6 0.8 1.0
Liquid
steel
Door
panel
40 GJ/t 30 GJ/t 20 GJ/tWith both eyes open — diverting scrap
If we can’t eliminate yield
losses can we divert scrap?
• Trim and sell sheet and plate skeletons • Solid bonding of aluminium swarf
With both eyes open — re-use without melting
Steel re-use in construction has begun
• Certification and irregular supply are problems • Availability in the UK is rapidly increasing
• Profit possible but decision timing is a challenge Old building Deconstruction Design Recondition/ Certification Fabricate Construction New building
Identify source building Strip building and
deconstruct frame
Design around available stock to minimize overuse Clean, remove fixings; coupon (or other) test; negotiate insurance Cut and weld
As normal Share messages 0 250 1000 750 500 Year Tonnage per y ear (kt) 1900 1970 2040
Annual consumption of structural sections
Predicted annual availability of reclaimed sections 200 0 2006 2009 400 600 800 Profit opportunity Reconditioning costs Deconstruction cost Compensation for scrap
£ (2009) per t onne Year Building unoccupied Demolition Project timeline Construction Decision points
With both eyes open — longer life products
Time
Cumula
tiv
e Emissions
More frequent replacement Less frequent replacement
0 2000 8000 4000 Time Cumula tiv e P rofit (£) 6000
Control systems (5yr) Work rolls (2-5yr) Back-up rolls (15yr) Motors (20yr) Cooling/hydraulic systems (20yr) Gearboxes (40yr) Structure (40-100yr) 50% 100% 0% Steel Share Steel strip rolling mill Cost Share ... relative to when it
was purchased ... relative to what’s now available The product’s
perfor-mance has declined ... Degradede.g. rail track e.g. washing machinesInferior
The product’s value
has declined ... Unsuitablee.g. sports car e.g. single hulled oil tankersUnwanted
With both eyes open — reducing final demand
If not material efficiency,
then demand reduction?
• More intense use?
• Deliver the material service with less material?
• Consume less?
0% 100%
50%
Income per head ($/year)
Happiness
0 20,000 40,000
USA Japan
New Zealand Netherlands
Russia
SERVICE
SPACE
END OF PHYSICAL LIFEUSE
PROFILE
POINT OF DISCARD DESIGN CAPACITYUse more
frequently
Time
In
tensit
y of use
Increase
capacity
Reduce
capacity
Pass on
Repair or
upgrade Make more
durable
Use at full
design
capacity
With both eyes open — scenario building
For all products
• Establish current averages • Anticipate future limits
for each option
• Validate with industry partners
Less metal by design
Reuse of components
Life
extension More intense use
0% 40% 100 kg/m2 72 kg/m2 40 years 80 years 40 hr/wk 80 hr/wk Less metal by design Yield loss reduction Scrap diversion
Reuse of Life More
0% 85% 40% 20% 0% 30% 1300 kg 300 kg 14 years 20 years 500 p-km/wk 1000 p-km/wk
With both eyes open — scenario analysis
0 1 2 3 4 5 Gt CO2BAU
Process efficiency
6Target
Process+ material
efficiency
Current (2008)
0 0.3 0.6 0.9 1.2 1.5 Gt CO2 BAU Process Efficiency 1.8 Target Process + material efficiency Material Efficiency Current (2007)Aluminium
Steel
0% 50% 25% 75% 100%Less metal by design
0% 50% 25% 75% 100% Mor e int ense use 0% 50% 25% 75% 100% Scr ap div ersion 0% 50% 25% 75% 100% Reuse of componen ts 0% 50% 25% 75% 100%
Yield loss reduc
tion 0% 50% 25% 75% 100% Lif e Ex tension 0% 50% 25% 75% 100%
Less metal by design
0% 50% 25% 75% 100% Mor e int ense use 0% 50% 25% 75% 100% Scr ap div ersion 0% 50% 25% 75% 100% Reuse of componen ts 0% 50% 25% 75% 100%
Yield loss reduc
tion 0% 50% 25% 75% 100% Lif e Ex tension
Life extension, more intense use and using less metal by design are the most effective strategies
Implementation
Office
block
Rolling
mill
Car
Fridge
Mass of liquid steel (kg/pers/yr) 43 1.7 58 2.6
Spending (£/pers/yr) 560 6 600 13
Equivalent labour (hrs/pers/yr) 50 0.3 33 1
Conclusions
• With one eye open: we cannot reduce emissions enough if demand for new material grows as forecast
• With both eyes open: we have a lot of options for living well with less new material
