SUSTAINABLE MATERIALS

Transcription

1 SUSTAINABLE MATERIALS WITH BOTH EYES OPEN JULIAN M ALLWOOD UNIVERSITY OF CAMBRIDGE

2 Steel, aluminium and climate change Buildings 31% 7% Energy/ process emissions 28 GtCO 2 Transport 27% Industry 35% Focus on CO 2 IPCC says it s urgent Steel and aluminium have a big impact but not receiving much attention 45% Industrial carbon emissions 1 GtCO 2 Steel 25% Cement Aluminium Paper 19% 3% Plastic 4% 4% Key challenges Scale Uncertainty Estimates

3 Steel and aluminium in use Infrastructure 15 Mt 14 % Metal goods 134 Mt 12 % Steel 1,4 Mt Buildings 433 Mt 42 % Mechanical equipment 137 Mt 13 % Cars and light trucks 93 Mt 9 % Trucks and ships 28 Mt 3 % Domestic appliances 29 Mt 3 % Electrical equipment 27 Mt 3 % Consumer packaging 9 Mt 1 % Buildings 11 Mt 24 % Cars 8 Mt 18 % Packaging 6 Mt 13 % products 4 Mt 9 % Electrical cable 4 Mt 9 % Mechanical equipment 3 Mt 7 % Trucks 3 Mt 7 % Appliances 3 Mt 7 % Electrical equipment 2 Mt 4 % transport 1 Mt 2 % Aluminium 45 Mt Image: Jaguar

4 Demand for steel and aluminium Production (kg/person/year) Production stabilises... Stock (tonnes/person) stocks stabilise , 2, 3, GDP ($/person/year) Stock (tonnes/person) 16 Japan Canada US UK 8 France China India so we can forecast demand 3 Mt/yr 15 Primary production Secondary production Challenge Over the next 4 years we expect demand to double, but must halve our CO 2 emissions Production + recycling Approach Forecast flows, anticipate emissions factors, predict business shape

5 Global flows of steel Iron ore Reduction Blast furnace Steelmaking Casting Rolling / Forming Fabrication End-use products Oxygen blown furnace Continuous casting (slab) Hot strip mill Cold rolling mill Cold rolled coil CRC coated CRC galv. Tin plated Electrical strip Vehicles Cars Trucks Direct reduction Open hearth furnace Ingot Primary mill Plate mill HRC galv. Hot rolled coil HR narrow strip Plate Industrial equipment Mechanical Electrical End-of-life scrap Scrap preparation Electric furnace Continuous casting (billet) Rod and bar mill Welded pipe Seamless tube Reinforcing bar Cladding Construction Reinforcing Infrastructure Wire rod Structural Continuous casting (bloom) Section mill Hot rolled bar Rail section Light section Heavy section Metal products Packaging Appliances Steel product casting Iron foundry casting Cast steel Cast iron Forming scrap Fabrication scrap Cast iron scrap Global demand in 28 for steel products = 1,4 million tonnes 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

6 Process energy analysis steel Blast furnace 16 EJ 7 % Direct reduction.7 EJ Basic oxygen furnace.2 EJ Electric arc furnace 2.7 EJ 86 % Continuous casting.4 EJ 74 % Rolling 3.6 EJ 46 % Coating.6 EJ 46 % Forming.2 EJ 82% Steel (overall) Energy = 38 EJ Electricity = 39 % Shape casting 2.1 EJ 46 % Fabrication 6-11 EJ 7 % Images: worldsteel Process energy data is commercially sensitive and incomplete Energy for producing liquid metal dominates for both metals

7 Global flows of aluminium Electrolysis / Melting Casting Rolling / Forming / Casting Fabrication End-use products Alumina Electrolysis Casting Hot rolling Cold rolling Foil rolling Foil Vehicles Cars Cold rolled sheet Remelting Extrusion Wire drawing Hot rolled strip Plate Extrusions Industrial equipment Mechanical Cable Electrical Forming scrap Cable / wire Construction Structural Non-structural Fabrication scrap Refining Forming scrap Fabrication scrap End-of-life scrap Casting Shape casting Die castings Permanent castings Sand castings Metal products Infrastructure Drinks cans Packaging foil Durables Global demand in 27 for aluminium products = 45 million tonnes Messages 4 of liquid metal never reaches products but is scrapped in production Aluminium recycling mainly leads to casting alloys for engine blocks

8 Process energy analysis aluminium Alumina mining +refining 1.1 EJ 2 % Electrolysis 5. EJ 1 % Scrap remelting.4 EJ 3 % Ingot casting.5 EJ 44 % Rolling.23 EJ 72 % Extrusion +drawing.9 EJ 19 % Scrap refining.15 EJ 14 % Alloy ingot casting.3 EJ 44 % Shape casting.17 EJ 1 % Fabrication.3-.6 EJ 7 % Aluminium (overall) Energy = 7.6 EJ Electricity = 76 % Process energy data is commercially sensitive and incomplete Energy for producing liquid metal dominates for both metals

9 Business structure Retailers Consumer goods industry Maintenance providers Part suppliers Food and drink Mining and minerals Equipment manufacturers Industrial equipment users Steel Aluminium Factory designers Metal products Industrial equipment Food industry Appliance manufacturers Fillers Packaging manufacturers Ship builders Metal products Transport goods Machinery and equipment manufacturing Utilities Construction Food and drink Transport services business and public services Energy providers Developers Architects Planners Surveyors Contractors +tradesmen Construction Utility companies Estate agents Building Demolition engineers companies Vehicles Logistics companies Stockholders Mining and minerals Maintenance providers Airlines Aircraft manufacturers Dealers Car + truck manufacturers Leasing companies Fabricators Steel Steel+ aluminium industries Aluminium Metal products Transport goods Machinery and equipment manufacturing Utilities Construction Transport services business and public services Government NGOs Lobby groups Trade associations Insurance providers Universities Financial services Refiners Mining industry Consumers Scrap merchants Landowners

10 The story so far... The world of steel and aluminium Demand is likely to double but we want to halve emissions in 4 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 Do we have other options if we consider changing the flows?

11 With one eye open energy efficiency? Electricity 3.6% 24% Gas 6.5% Steel production costs Ferrous raw materials 4 Coke 26% Labour +other materials 37% 3% Aluminium production costs Alumina 25% Energy 35% About 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 GJ/t crude steel Average 15 Best practice = 12.5 GJ/t Theoretical minimum = 6.6 GJ/t MWh/t aluminium 16 Average Best practice = 13 MWh/t 12 8 Theoretical minimum = 9 MWh/t

12 With one eye open heat capture? Temperature (ºC) Casting Hot work Heat treatment Primary processes Rebar Car body Forged mining part Chassis plate Wire Image: Siemens Time Electricity generation Hot metal Primary energy Hot metal Primary energy Electricity generation Casting Hot rolling ESP Losses We could cut out heating cycles, but this will deny some economies of scale Losses Heat capture from hot gases is common, from solids is more difficult

13 With one eye open new process routes? Gas scrubber Used gas Iron ore pellets Off gas duct Steel Reformer Reformed gas Natural gas Gas scrubber Used gas Cool clean gas Directly reduced iron ready for the electric arc furance Melting cyclone Smelting reduction vessel Oxygen Point feeders break crust and introduce metal oxide here Cell sidewall - Collector bar Steel shell Anode Anode Molten oxide + electrolyte Metal pool Cell floor + Current feed Oxygen gas bubbles Frozen electrolyte Liquid cathode Direct reduced iron (to EAF) Smelt reduction + CCS Iron ore pyroelectrolysis Aluminium Alumina and carbon feed Vapour recovery Vapour recovery Aluminium Off gas Aluminium Pool Multipolar electrolysis cell Inert anodes Carbothermic reduction Images: worldsteel

14 With one eye open clean electricity? 1.95 W/m W/m 2.2 W/m 2.3 W/m 2 Credit: David MacKay

15 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 4 years 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 Images: worldsteel Image: CO2CRC

16 With one eye open scenarios Steel BAU Target Process Efficiency Options Current (28) Gt CO2 Aluminium BAU Target Process Efficiency Options With one eye open Current (27) Gt CO2 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 25 if demand doubles

17 With both eyes open what else can we do? Electrolysis / Melting Casting Rolling / Forming / Casting Fabrication End-use products Alumina Electrolysis Aluminium Casting Slab Hot rolling Cold rolling Foil rolling Foil Cold rolled sheet Vehicles Cars Remelting Aluminium Forming scrap Fabrication scrap Refining Billet Casting Extrusion Wire drawing Shape casting Hot rolled strip Plate Extrusions Cable / wire Die castings Use less by design Industrial equipment Reduce demand Mechanical Electrical cable Longer life goods Non-structural in buildings Infrastructure Drinks cans Aluminium Forming scrap Fabrication scrap End-of-life scrap Alloy ingot Re-use old metal Divert scrap Permanent mould castings Sand castings Reduce yield loss Metal products Packaging foil Consumer durables Global demand in 27 for aluminium products = 45 million tonnes

18 With both eyes open use less by design 5 principles of lightweight design α 1 α 2 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 supports Rewrite standards New processes

19 With both eyes open reduce yield losses 1 Steel We scrap more than a quarter of our liquid metal 5 Aluminium Blanking, trimming and machining are the main causes Additive manufacture does not provide a solution I-beam Car doors Drinks can Wing skin Novel forming processes are required combined with casting to make intermediate products closer to final shapes Cumulative process energy (GJ/t liquid steel) 2 1 Door panel 4 GJ/t 3 GJ/t Cumulative Yield (t output/t liquid steel) 2 GJ/t Liquid steel

20 With 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 Market for over-ordered stock

21 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 Tonnage per year (kt) 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 (29) per tonne Year Annual consumption of structural sections Predicted annual availability of reclaimed sections Year Building unoccupied Profit opportunity 29 Reconditioning Demolition Decision points costs Deconstruction Construction cost Project timeline Compensation for scrap

22 With both eyes open longer life products The product s performance has declined... The product s value has declined relative to when it was purchased Degraded e.g. rail track Unsuitable e.g. sports car... relative to what s now available Inferior e.g. washing machines Unwanted e.g. single hulled oil tankers Cumulative Emissions Control systems (5yr) Steel Share Cost Share Time Work rolls (2-5yr) Cumulative Profit ( ) More frequent replacement Less frequent replacement Time Back-up rolls (15yr) Motors (2yr) Cooling/hydraulic systems (2yr) Gearboxes (4yr) Structure (4-1yr) 5 1 Steel strip rolling mill

23 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? 1 New Zealand Netherlands USA Japan DESIGN CAPACITY Use at full design capacity Increase capacity Use more frequently SERVICE SPACE Reduce capacity Happiness 5 Russia 2, 4, Income per head ($/year) Intensity of use USE PROFILE Time Pass on POINT OF DISCARD Repair or upgrade Make more durable END OF PHYSICAL LIFE

24 With both eyes open scenario building 72 kg/m2 1 kg/m2 For all products Establish current averages Less metal by design 4 3 kg 2 85% 13 kg 4 Reuse of components 8 years 8 hr/wk 4 years 4 hr/wk Less metal by design 3 Anticipate future limits for each option Validate with industry partners Life extension More intense use Reuse of components Yield loss reduction Scrap diversion 2 years 1 p-km/wk 14 years 5 p-km/wk Life extension More intense use

25 With both eyes open scenario analysis With both eyes open we have enough options to cut emissions by Process Efficiency Process + material efficiency Material Efficiency Aluminium.3 75% 75% 75% 75% 75% % 25% 25% 25% 25% 25% Less metal by design Target 75% Current (28) Gt CO2 BAU Current (27) Gt CO2 More intense use 2 1 Life Extension Steel 1 1 Reuse of components 1 Scrap diversion Process+ material efficiency % 75% 75% 75% 75% 75% % 25% 25% 25% 25% 25% Scrap diversion Reuse of components Life Extension More intense use Process efficiency 1 Yield loss reduction Target Less metal by design Yield loss reduction BAU Life extension, more intense use and using less metal by design are the most effective strategies

26 Implementation Office block Rolling mill Car Fridge Mass of liquid steel (kg/pers/yr) Spending ( /pers/yr) Equivalent labour (hrs/pers/yr) liquid steel (kg/pers/yr)

27 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