thermodynamic analysis of resources used in manufacturing
TRANSCRIPT
Manufacturing, Renewable Energy and Thermodynamics
Timothy G. Gutowski [email protected]
Spring, 2009
2
Outline
1. The role of mfg in renewable energy
2. Thermodynamic analysis of mfg process
3. How to improve mfg processes
4. How to improve renewable energy
3
Role in “New Energy”
4
Energy Payback
Time to breakeven = tB = Em/e
Energy Return on Energy Investment = EROI = etL/Em
Em
e
t = 0 1 2 3 4 5… tL
5
Efficiencies of Energy Production, “e”
η = energy outenergy in
ηCarnot =work outheat in
= (1− TLTH
)
6
Efficiencies of Energy Production, Photovoltaic
ηPV PV: Shockley - Queisser Limit For a simple single junction
Device depends on band-gap ~30%
ηPV =eouteavail
eout = ηPVeavail
7
Efficiencies of Energy Production, Wind
ηWind Wind: Betz Limit ~59%
ηWind =eouteavail
eout = ηWindeavail
8
Efficiencies of Energy Production, Nuclear Power
ηCarnot Nuclear: Carnot Limit
η = energy outenergy in
ηCarnot =work outheat in
= (1− TLTH
)
9
Efficiencies of Mfg Energy Requirement, “Em”
ηmfg =Eoutput ??Ein
How to calculate the thermodynamic efficiency of a
materials transformation process?
The minimum work to transform materials =
change in available energy or “exergy” (B) of the materials
Wmin = Bout - Bin
11
Efficiencies of Mfg Exergy Requirement, “Bin”
ηmfg =BoutputBin
= ηP
Bin =BoutputηP
ηP = ?
12
Rewriting…
tB =Emfg
e≅Exergy inputs for mfg
Exergy output
tB =Bineout
=Bout
ηPηeeavailable
EROI =etLEmfg
≅eavailableηPηetL
Bout
13
Current Estimates*
Time to break even
• Wind ~ 1 year
• Nuclear ~2-5 years
• PV ~ 2 to 5 years
EROI**
• Wind ~ 25
• Nuclear ~ 10 to 30
• PV ~ 5 to 12
*Values can range considerably, these agree with Smil 2008 **Using TL of 25 yrs for PV and Wind, and 50 yrs for Nuclear. NOTE: PV and Wind do not include storage
14
Mfg Process
Equipment Raw Materials
Energy
Product
Wastes
Thermodynamic Analysis of Resources Used in Manufacturing Processes
15
Energy Conversion
Mfg Process
Equipment
16
Aux. Mfg Process
Equipment
Energy Conversion
Energy Conversion
Energy Conversion
Mfg Process
Equipment
Mfg Process
Equipment
17
Aux. Mfg Process
Equipment
Materials Production
Energy Conversion
Energy Conversion
Energy Conversion
Energy Conversion
Mfg Process
Equipment
Mfg Process
Equipment
18
Aux. Mfg Process
Equipment
Materials Production
Energy Conversion
Energy Conversion
Energy Conversion
Energy Conversion
Auxiliary Materials
Production
Mfg Process
Equipment
Mfg Process
Equipment
Energy Conversion
19
Aux. Mfg Process
Equipment
Environmental Conditioning
Materials Production
Energy Conversion
Energy Conversion
Energy Conversion
Energy Conversion
Auxiliary Materials
Production
Mfg Process
Equipment
Mfg Process
Equipment
Energy Conversion
20
Aux. Mfg Process
Equipment
Environmental Conditioning
Materials Production
Energy Conversion
Energy Conversion
Energy Conversion
Energy Conversion
Energy Conversion
Auxiliary Materials
Production
Alt. Materials
Production
Mfg Process
Equipment
Mfg Process
Equipment
Energy Conversion
21
Aux. Mfg Process
Equipment
Environmental Conditioning
Materials Production
Energy Conversion
Energy Conversion
Energy Conversion
Energy Conversion
Energy Conversion
Auxiliary Materials
Production
Materials Purification Production
Mfg Process
Equipment
Mfg Process
Equipment
Energy Conversion
22
Hybrid Input Output Analysis (transportation, capital equipment, other materials, commercial buildings…
Thermodynamic Analysis: Materials Transformation,
Open System
24
Balance Equations
25
26
In terms of Minimum Work
27
Chemical Properties referenced to the “environment”
Crust
Oceans
Atmosphere
T0 = 298.2 K, P0 = 101.3 kPA
28
Exergy Reference System
pure metal, element
oxides, sulfides…
crustal component earth’s crust (ground state)
chemical reactions
extraction
29
Exergy Reference System
Aluminum (c=1) 888.4 kJ/mole
Al2O3 (c=1) 200.4 kJ/mole
Al2SiO5 (c=1) 15.4kJ/mole Al2SiO5 (c = 2 x 10-3) 0 kJ/mole (ground)
30
Example; making pure iron from the crust
Fe (c = 1) 376.4 kJ/mole
reduction
Fe2O3 (c=1) 16.5 kJ/mole extraction
Fe2O3 (c = 1.3 x 10-3) 0 kJ/mole (ground)
31
32
Extraction from the crust
molekJ
KmoleJKB
xRTB
oo
o
5.16103.1
1ln314.82.298
103.11ln
1c to(crust)1.3x10c from OFe Extracting
3
3
332
=×
××=
=
==
−
−
−
Note: R = k Navo (Boltzmann’s constant X Avogadro’s number)
33
Reduction of Fe2O3 (Hematite)
2Fe2O3 + 3C 4Fe + 3CO2
Output = 4 x 376.4 – 3 x 19.9 - Input = -(2 x 16.5 + 3 x 410.3)
Wmin = 301.4 kJ
34
Actual exergy expenditure = ∑ Binputs
Work
Heat
Materials
Product
Wastes
Bproduct ≤ Bb
35
Iron Ore Reduction
the actual reaction is
2Fe2O3 + 12.42C + 9.42O2 4Fe + 12.42CO2 33kJ + 5095.9 + 37.7 - 1505.6 - 247.2kJ =
actual work = 3,413.8 kJ for 4 mole of Fe
ηP = 1505.6/5166.6 = 0.29
36
Manufacturing Systems as open thermodynamic systems
Mfg Systems
Gutowski et al ES&T 2009
37
Balances for Mfg Process
38
Work Rate for Mfg Process in Steady State
39
Exergy and Work
Bra
nham
et a
l IE
EE
ISE
E 2
008
Examples: plastic work, melting, vaporizing etc.
40
Physical & Chemical Exergy
Here all chemical exergy terms (bch) are at To, Po
Branham et al IEEE ISEE 2008
41
Example Calculations Second Law Efficiency; Degree of Perfection
• Induction melting or iron • PECVD of SiO2 • Thermal Oxidation of SiO2
42
Gray Iron Products 1000 kg
Slag 24 kg
Dust 0.26 kg
Induction Melting Exergy Analysis
Metallic Input Materials Alloys 1024 kg
Electricity 1798 MJ
Boundaries are drawn around the entire facility, all components are at standard pressure and temperature
Natural Gas Preheater 0.025 kg
43
Batch Induction Melter Exergy Analysis*
Material Amount (kg) Weight PercentStandard Chemical
Exergy (MJ/kg) Exergy (MJ)Percent Total
Exergy
Steel Scrap 439 42.85% 6.89 3022.25 15.39%Pig Iron 1.6 0.16% 8.18 13.43 0.07%Ductile Iron Remelt 535 52.25% 8.44 4513.98 22.99%65% Silicon Carbide Briquettes 4.3 0.42% 31.73 137.62 0.70%75% Ferrosilicon 3.0 0.29% 24.51 72.46 0.37%5% MgFeSi 14.8 1.44% 19.09 282.30 1.44%Copper 1.7 0.17% 2.11 3.69 0.02%Tin 0.005 0.00% 1.13 0.01 0.00%62% Fe-Molybdenum 6.2 0.61% 7.28 45.35 0.23%Carbon 9012 18 1.80% 34.16 628.45 3.20%Natural Gas Preheater 0.02 0.00% 51.84 1.27 0.01%Electricity 5418.00 55.59%
Total Inputs 1024 100.00% 14138.83 100.00%
Ductile Iron Melt 1000.2 96.69% 8.44 8436.45 99.29%Slag 33.9 3.28% 1.14 60.05 0.71%Dust 0.3 0.02% 0.26 0.07 0.00%
Total Outputs 1034 100.00% 8497 100.00%
Mass Difference -1.05%
Ductile Iron Batch Electric Induction Melting
Input Materials
Output Materials
*including losses at Utility
44
Batch Electric
Induction Melting
of 1 kg of melt
Total Exergy In
(Bin) = 11,155,000 J Useful Exergy Out (Bout) = 8,250,000J
Component Exergy in (J) Metallics 8,700,000 Electricity* 2,455,000
Batch Electric Degree of Perfection
Degree of Perfection
*not including utility losses
45
Plasma Enhanced Chemical Vapor Deposition (CVD)
SiH4 (gas) + 2N2O (gas) → SiO2(solid) + 2N2 (gas) 2H2 (gas)
46
Input Deposition Gases Species Input mass
(g) Input moles or primary energy
Exergy (J) %Total Inputs
SiH4 0.95 0.029579mol 40928.6 0.749 O2 0.49 0.015313mol 60.79 Ar 0.34 0.008511mol 99.5 N2 196.9 7.028779mol 4849.9
Input Cleaning Gases CH4 69.41 4.326643mol 3598253 63.0 NF3 31.06 0.437453mol 266931.6
Input Energy Electricity 2220000J 2220000 36.2
Outputs Undoped Silicate
Glass laye 0.0248 0.000414mol 3.2667 P
lasm
a enhanced C
VD
47 Data from Sarah Boyd et. al. (2006)
Chemical Vapor Deposition (CVD)
of a 600nm Undoped Silicate Glass (USG) layer
at 400°C
Total Exergy In
(Bin) = 6,130,000J Useful Exergy Out (Bout) = 3.3J
Component Exergy in (J) Input Gases 45,900 Cleaning Gases 3,865,000 Electricity* 2,220,000
Degree of Perfection
CVD Degree of Perfection
*not including utility losses
48
Thermal (Wet) Oxidation
Si (solid) + H20 (vapor) → SiO2 (solid) + 2H2 (gas)
49
Input Gases Species Input mass (g) Input moles or
energy (J) Exergy (J) %Total Input
Exergy N2 54.069 1.9301 1331.769 0.00089 O2 6.1399 0.19188 761.7636 0.00051 H2 0.4479 0.22218 52456.7 0.0351
Silicon Consumed from Substrate Si 0.03091 0.001101 940.54 0.00063
Input Energy Electricity 149256000 149256000 0.99963
Outputs SiO2 layer 0.066253 0.001103 8.711
degree of perfection ηP = 5.83*10
-8
Wet Oxidation Pro
cess
Branham
50
Summary for ηP
• Heating & Melting ~ 0.5
• Machining ~ 0.05
• Grinding ~ 0.005
• Sputter, Wet and Dry Etching ~ 5 X 10-4
• PECVD (SiO2) ~ 10-6
• Wet Oxidation ~ 10-8
51
Comments
• These can be quite sensitive to rate when idle power is high
• Transit Exergy for melting processes • Exergy of Auxiliary materials: etching,
cleaning, pollution abatement, abrasive waterjet
• Also affected by exergy of the output
52
Energy (Electricity) Only
1. Machining 2. Grinding 3. Casting 4. Injection Molding 5. Abrasive Waterjet 6. EDM 7. Laser DMD 8. CVD 9. Sputtering 10. Thermal Oxidation
53
Energy Requirements at the Machine Tool
Jog (x/y/z) (6.6%)
Machining (65.8%)
Computer and Fans (5.9%)
Load
Constant (run time) (20.2%)
Variable (65.8%)
Tool Change (3.3%)
Spindle (9.9%)
Constant (startup) (13.2%)
Carousel (0.4%)
Unloaded Motors (2.0%)Spindle Key (2.0%)
Coolant Pump (2.0%)Servos (1.3%)
Jog (x/y/z) (6.6%)
Machining (65.8%)
Computer and Fans (5.9%)
Load
Constant (run time) (20.2%)
Variable (65.8%)
Tool Change (3.3%)
Spindle (9.9%)
Constant (startup) (13.2%)
Carousel (0.4%)
Unloaded Motors (2.0%)Spindle Key (2.0%)
Coolant Pump (2.0%)Servos (1.3%)
Production Machining Center Automated Milling Machine
From Toyota 1999, and Kordonowy 2002.
54
Electric Energy Intensity for Manufacturing Processes
Pow
er (k
W)
Process Rate (cm3/sec)
physics
auxiliary equipment & infrastructure
Process Rate (cm3/sec) Spe
cific
Ene
rgy
(MJ/
cm3)
55
Injection Molding Machines
0
1
2
3
4
5
6
7
8
0 50 100 150 200Throughput (kg/hr)
SEC
(M
J/kg
)
HP 25HP 50HP 60HP 75HP 100Low Enthalpy - Raise Resin to Inj. Temp - PVCHigh Enthalpy - Raise Resin to Inj. Temp - HDPE
Variable Pump Hydraulic Injection Molding Machines.
Does not account for the electric grid.
Sour
ce: [
Thiri
ez ‘0
6]
56
Thermal Oxidation, SiO2
Ref: Murphy et al es&t 2003
57
Power Requirements
Ref: Murphy et al es&t 2003
58
Injection Molding 10.76 - 71.40 3.76 - 50.45of polymer processed
1.75E+03 - 3.41E+03 [Thiriez 2006]
Machining 2.80 - 194.80 0.35 - 20.00of material removed
3.50E+03 - 1.87E+05[Dahmus 2004], [Morrow, Qi &
Skerlos 2004] & [Time Estimation Booklet 1996]
Finish Machiningof material removed
[Morrow, Qi & Skerlos 2004] & [Time Estimation Booklet
1996]
CVD 14.78 - 25.00 6.54E-05 - 3.24E-03of material
deposited on wafer area
4.63E+06 - 2.44E+08
[Murphy et al. 2003], [Wolf & Tauber 1986, p.170], [Novellus
Concept One 1995b] & [Krishnan Communication
2005]
Sputtering 5.04 - 19.50 1.05E-05 - 6.70E-04of material
deposited on wafer area
7.52E+06 - 6.45E+08[Wolf & Tauber 1986] &
[Holland Interview]
Grinding 7.50 - 0.03 1.66E-02 - 2.85E-02of material removed
6.92E+04 - 3.08E+05[Baniszewski 2005] & [Chryssolouris 1991]
Waterjet 8.16 - 16.00 5.15E-03 - 8.01E-02of material removed
2.06E+05 - 3.66E+06 [Kurd 2004]
Wire EDM 6.60 - 14.25 2.23E-03 - 2.71E-03of material removed
2.44E+06 - 6.39E+06 [Sodick], [Kalpakjian &
Schmid 2001], & [AccuteX 2005]
Drill EDMof material removed
[King Edm 2005] & [McGeough, J.A. 1988]
Laser DMDof material removed
[Morrow, Qi & Skerlos 2004]
Thermal Oxidation 21.00 - 48.00 4.36E-07 - 8.18E-07of material
deposited on wafer area
2.57E+10 - 1.10E+11 [Murphy et al. 2003]
Process Name ReferencesPower Required
kW
Electricity Required
J/cm3
9.59 2.05E-03 4.68E+06
Process Rate
cm3/s
2.63 1.70E-07 1.54E+10
80.00 1.28E-03 6.24E+07
59
In General, over manymanufacturing processes,
60
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E-07 1.E-05 1.E-03 1.E-01 1.E+01 1.E+03
Process Rate [cm 3/s]Injection Molding Machining Finish MachiningCVD Sputtering GrindingAbrasive Waterjet Wire EDM Drill EDMLaser DMD Oxidation Upper BoundLower Bound
Elec
trici
ty R
equi
rem
ents
[J/c
m3 ]
Specific Energy Requirements J/cm3
for Various Mfg Processes
Gut
owsk
i et a
l IE
EE
, IS
EE
200
7
61
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E-07 1.E-05 1.E-03 1.E-01 1.E+01 1.E+03
Process Rate [cm 3/s]Injection Molding Machining Finish MachiningCVD Sputtering GrindingAbrasive Waterjet Wire EDM Drill EDMLaser DMD Oxidation Upper BoundLower Bound
Elec
trici
ty R
equi
rem
ents
[J/c
m3 ]
Specific Energy Requirements J/cm3
for Various Mfg Processes
Conventional Processes
Advanced Processes & Mico/Nano
8 or
ders
of m
agni
tude
G
utow
ski e
t al
IEE
E, I
SE
E 2
007
62
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E+13
1.E+14
1.E-06 1.E-04 1.E-02 1.E+00 1.E+02 1.E+04
Process Rate [kg/hr]Injection Molding Machining Finish MachiningCVD Sputtering GrindingAbrasive Waterjet Wire EDM Drill EDMLaser DMD Oxidation Melters
Elec
trici
ty R
equi
rem
ents
[J/k
g]
Gut
owsk
i et a
l IE
EE
, IS
EE
200
7
63
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
1.E+13
1.E+14
1.E-06 1.E-04 1.E-02 1.E+00 1.E+02 1.E+04
Process Rate [kg/hr]Injection Molding Machining Finish MachiningCVD Sputtering GrindingAbrasive Waterjet Wire EDM Drill EDMLaser DMD Oxidation Melters
Elec
trici
ty R
equi
rem
ents
[J/k
g]
Gut
owsk
i et a
l IE
EE
, IS
EE
200
7
64
Why are these energy intensities so high?
• demand for small devices, prices for energy & materials stable/declining
• vapor phase processes with slow deposition rates
• efficiency used to enhance performance, not to downsize equipment
• However, the trajectory of individual processes is usually toward faster rates and lower energy intensities
65
Keep in Mind
• This is intensity not total used
• This is at the process, not cumulative exergy! – loses at energy conversion not included
– investment into materials not included
– infrastructure not included
How to Improve mfg processes
67
Melting & Machining
Mostly Vapor Phase Processes
Original microlathe and original micro milling machine
1 mm
Size Mass m =
Spindle power PRotational speed
W x D x H =
n =S =
max
32 x 25 x 30.5 mm98 g1.6 W10,000 min
3
-1
Size Spindle power P
Rotational speed
W x D x H =
n =S =
max
170 x 170 x 102 mm36 W15,600 min
3
-1
Microlathe
Micro milling machine
5 mm
Spindle drive
ToolTool
Spindle drive
ToolTool
Source: [EHMA05, MEL07, TANA01]
Sample parts
68
Improve process rate
Kalpakjian
69
Turn un-needed equipment off
0
1
2
3
4
5
6
7
8
9
0 5 10 15 20Throughput (kg/hr)
All-Electric - 85 tons
Hydraulic - 85 tons
SEC
(MJ/
kg)
Material: PP
Source: [Thiriez 2006]
70 Matthew Branham
71
Use Less Materials
In ID and wire sawing of Si ingots, the kerf material represents lost exergy String-Ribbon
Invented by Ely Sachs saves this material
72
Change Basic Mechanism
Xerox goes from grinding to emulsion polymerization To produce toner particles
73
Returning to renewable energy
tB =Emfg
e≅Exergy inputs for mfg
Exergy output
tB =Bineout
=Bout
ηPηeeavailable
EROI =etLEmfg
≅eavailableηPηetL
Bout
74
Summary Comments
• Manufacturing processes can be treated
as thermodynamic processes
• They play an important role in renewable
energy
Thank You
[email protected] Google: Environmentally Benign
Manufacturing
Ref paper:
Gutowski, Branham, Dahmus, Jones, Thiriez and Sekulic Thermodynamic Analysis of Resources Used in Manufacturing Processes,
Environ. Sci. Technol., 2009, 43, 1584-1590