Gerardo J. Ruiz-Mercado

GREENSCOPE: A Tool for Chemical Process Sustainability Assessment and Design

U.S. Environmental Protection AgencyOffice of Research and DevelopmentNational Risk Management Research LaboratorySustainable Technology Division

Carnegie Mellon University, Pittsburgh, PA

05-02-2013

Michael A. GonzalezPhD, Chemistry

Developers

Gerardo Ruiz-MercadoPhD, Chemical Engineering

Raymond SmithPhD, Chemical Engineering

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What is GREENSCOPE?

• Foundations• Quantification of Sustainability for Chemical Processes• Methodology

–Taxonomy–Data Needs

2

–Data Needs• Application• Tool

–Excel®

–Java• Global Sustainability Assessment• Conclusions

Motivation

� Fundamental businesssector for the globaleconomy and society’squality of life

• Exposure of workers to toxic and carcinogenic substances

• Water pollution, air

The finite availability and accelerated depletion of ecological goods and services: The role of the chemical Industry

3

quality of life� 5% of the U.S. nominal

gross domestic product� directly employs ≅ 800,000

people nationwide� 11% of all U.S. patents /yr� 96% of all final goods are

directly influenced

• Water pollution, air emissions and solid waste

• Product use impacts: e.g., agrochemicals, fossil fuels

• Disposal impacts: e.g., flame retardant substances, paint pigments

• 6% of the total U.S. energy consumption

Sustainability for Chemical Processes

• Guidelines to achieve quality of life improvements –without affecting the availability of ecological goods & services

– for new and existing manufacturing processes

• Address and assess environmental, social, and economic aspects that may be affected by industryeconomic aspects that may be affected by industry– identify which system components are affected

– localize process and product aspects which generate them

–redesign relevant processes and products

–demonstrate system improvements

• Minimize or eliminate the environmental impacts and maximizing the social/economic benefits

4

Quantitative Sustainability Assessment

• From qualitative to quantitative• Improvements achieved in one area may simultaneously affect

other areas negatively• A more sustainable process is the result of an optimal tradeoff

55

Sustainable Process Design Procedure

• Support decision-makers to determine whether a process is becoming more or less sustainable–Are we doing relatively good / bad?

• What benchmarks to use?• How close are we to achieving absolute targets?

6

Sustainability & Process Design

Specific process changes to improve sustainability atearly design stages will have greater potential influenceon the sustainability of the process during operation

7

7

Taxonomy of Chemical Process Indicators

Society

Environment

Sustainable development

Eco-efficiency Socio- economic

Socio-ecology

Rel

ease

s

Eco

l. go

ods

& s

ervi

ces

Revenues

Eco

n. g

oods

& s

ervi

ces

Releases

Ecol. goods & services • Triple dimensions of Sustainable

Development–Environment, Society, Economy–Corporate level indicators–Assessment at corporate level

• Four areas of sustainable chemical processes–Environmental, Efficiency, Economics, Energy (4E’s)–Process design level–Taxonomy of chemical process indicators for use in

process design8

Economy

Eco

l. go

ods

& s

ervi

ces

Eco

n. g

oods

& s

ervi

ces

–Assessment at corporate level

The GREENSCOPE Tool

• Clear, practical, and user-friendly approach• Monitor and predict sustainability at any stage of process

design• Currently developed into a spreadsheet tool, capable of

calculating 139+ different metrics• User can choose which indicators / metrics to calculate• User can redefine absolute limits to fit circumstances

9

GREENSCOPE Sustainability Framework

• Identification and selection of two reference states for each sustainability indicator:

– Best target: 100% of sustainability– Worst-case: 0% of sustainability

• Two scenarios for normalizing the indicators on a realistic measurement scale

• Dimensionless scale for evaluating a current process or tracking modifications/designs of a new (part of a) process

( )( ) ×Actual-Worst

Percent Sustainabilty Score = 100%Best-Worst10

GREENSCOPE: Systematic Evaluation Procedure

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Environmental Indicators

• 66 indicators

• Specifications of process input material

• Health & Safety hazards: operating conditions andoperation failures

• Impact of components utilized in the system and• Impact of components utilized in the system andreleases

• 100% sustainability, best target, is no releases ofpollutants and no hazardous material use or generation

• 0% sustainability, worst cases, all inputs are classifiedas hazardous, and/or all generated waste for eachpotential EHS hazard is released out of the process

12

Environmental Indicators: Example

( )× − •

•

=

−∆ ×=

∆− ∆ + ∆ <

=

2

fire/explosion

4 4

c,

fire/explosion

product

flash

flash, flash

Probable energy potential for reaction with OSH

Mass of product

10SH

If is known

0.005 1.0 if 0< 200

iIndVal

i i

i

i

H m

m

T

T T

IndVal

∆ ≤

flash1 if 0T

Safety hazard, fire explosion

Sustainability value

Best, 100% Worst, 0%

0 kJ/kgAll combustion enthalpy of each process substance is released

iIndVal

∆ ≥

= == = =

−

=

flash

flash

code

code

code

code

code

1 if 0

0 if 200

Elseif R is known

1 if R 12,15,17,18

0.875 if R 11,30

0.75 if R 10

0 if R other

Elseif NFPA f is known

1 if NFPA-flamm=4

0.833 if NFPA-fl

i

i

T

T

IndVal

IndVal

amm=3

0.667 if NFPA-flamm=2

0.5 if NFPA-flamm=1

0 if NFPA-flamm=0

end

∆Hc: combustion enthalpy, kJ/kg∆Tflash: temperature difference between the standard flash point and process temperature, ℃Rcode: Risk phrases of European communityNFPA-f: flammability hazard class according to the U.S. National Fire Protection Agency (NFPA)

13

Efficiency Indicators

• 26 indicators

• Amount of materials and inputs required to generate thedesired product (reaction) or complete a specificprocess task (e.g., separation)

• Mass transfer operations have implicit influence in theamount of energy demand, equipment size, costs, rawmaterials, releases, etc.

• Efficiency indicators connect material input/output withthe product or intermediate generated in the process oroperating unit

14

Efficiency Indicators: Example

Actual atom economy Sustainability valueBest, 100%

Worst, 0%

1 0( ) ( )( ) ( )

( )

reagentreagents

productproduct

Molecular weight stoichiometric coefficient

Molecular weight stoichiometric coefficient

Mass of product

Theoretical mass of product

MW

i

i

AAE AE

AE

mAAE

ε

ε

β •

= ×

× =×

=

× ×=

∑m•

product: mass flow of product I , kg/hm•in

limit. reagent: input mass flow rate of the limiting reagent, kg/hMWi: molecular weight of the component i, kg/kmolαi: stoichiometric coefficient of the reagent i( )

( )productproduct

reag

MW

MW

mAAE

α=

×in

limit. reagent product

productent, 1

limit. reagent limit. reagent

MWMW

I

ii

m βα

•

=× × ×∑

αi: stoichiometric coefficient of the reagent iβ product: stoichiometric coefficient of the desired product

Value mass intensity

V

in

,1

V

, product ,product 1

Total mass input

Sales revenue or value addedI

m ii

m

I

m m i m ii

MI

m

MIS

S m C

•

=

•

=

=

=

= ×

∑

∑

Sustainability valueBest, 100%

Worst, 0%

1 40

m•inm, i: input mass flow rate of the limiting reagent,

kg/hannual mass flow of substance i in year m, kg/yrSm: total income from all sales in year m, $ Cm, i: cost of material i in year m, $/kgm•

m, product, i: : annual mass flow of product i in year m, kg/yr15

Economic Indicators

• 33 indicators• A sustainable economic outcome must be achievedfor any new process technology or modificationproposed for the commercial scale

• Based in profitability criteria for projects (process,operating unit), may or may not account for the time

• Based in profitability criteria for projects (process,operating unit), may or may not account for the timevalue of money

• Indicators supported in cost criteria:–Processing costs: capital cost, manufacturing cost–Process input costs: raw material cost, utility costs–Process output costs: waste treatment costs

16

Economic Indicators: ExampleNet present value

Sustainability valueBest, 100% Worst, 0%

NPV @ discount rate

(rd)= 0%

NPV @ rd= minimum

acceptable rate of return

(MARR)=40% for very high risk

projects

( )( ),1

,

, product ,product 1

The total of the present value of all cash flows minus

the present value of all capital investments

PWF 1 rec

PWF

n

cf m m m m m mm

n

v m mm b

I

m m i m ii

m

NPV

NPV S COM d d

TCI

S m C

COM

=

=−

•

=

=

= − − − Φ + +

−

= ×

=

∑

∑

∑

( ), , , , ,0.280 2.73 1.23

0.1

L m OL m UT m WT m RM mFCI C C C C

d FCI

+ + + += projects

n: life of the plant or equipment, yrPWFcf,m: the selected present worth factorSm: total income from all sales in year m, $COMm: cost of manufacture without depreciation, $FCIL : Fixed capital investment without including the land valuedm: depreciation charge. Here, it is assumed as 10% of the FCIL evaluated in year m, however it can be estimated by different methods Φ: fixed income tax rate given by the IRSrecm: salvage-value recovered from the working capital, land value, and the sale of physical assets evaluated at the end of the plant life. Often this salvage value is neglected, $

( )

Land1

Land, ,

,1

, , ,

2

0.1

if rec =

0 if

C

1.18

4.5 annual salary

6.29 31.7 0

m L

n

L mm

m

m m L m m

u

L TM BM ii

o

BM i p i BM i

OL OL

OL

d FCI

C WC FCI d m n

m n

TCI FCI WC

FCI C C

C C F

C N

N P

=

=

= + + − = ≠

= + +

= =

== ×= + +

∑

∑

( )0.5

.23

Equipmentnp

np

N

N =∑

17

Energy Indicators

• 14 indicators

• Different thermodynamic assessments for obtaining anenergetic sustainability score

–Energy (caloric); exergy (available); emergy (embodied)

• Zero energy consumption per unit of product is the best• Zero energy consumption per unit of product is the besttarget (more products per unit of consumed energy)

• Most of the worst cases do not have a predefined value

–They depend on the particular process or process equipment

–The designer has to choose which value is unacceptable

–Some worst cases can be assigned by taking the lowestscores found through comparing several sustainabilitycorporate reports

18

Energy Indicators: Example

Exergy intensity

( ) ( )( ) ( )

( ) ( )( )

• in

• in • •

input flows• •

in• in ch

0 01 1 1

lost

pr uc

1

od t

Net exergy used

Mass of productEx

Ex = Ex physical + Ex chemical

+ Ex work + Ex heat

Ex = Ex l

E

n

x

Ex

Ex

J J c c

j i i i i ijj j i i j

R

R

m H T S n

m

x RT x x• •

= = =

•

•

=

=

=

∆ − ∆ + +

−

∑ ∑ ∑ ∑ �

b vf p, p,

b b

ln ln298K

L

L V L

T H TS S C C

T T

∆∆ = ∆ + − +

� �

�

� �

p,

b

ln L

L

TC

T

�

b vf p,

b

ln298K

L V

T HS S C

T

∆∆ = ∆ + −

� �

�

�

Sustainability valueBest, 100% Worst, 0%

0 Max Extotal/kg product

1 1 1 1j j i i j

kW

= = = =

+ ( )'

0 ,1 1

lost 0 generated

'in out

generated1 1 1

0

, , , , mix , , , , mix1 1

1 /

Ex =

K K

k kk k

J J K

k

j j j jj j k

c c

L j i j L ij L j V j i j V ij V ji i

Q T T

T S

QS m S m S

T

S x S S S y S S

•

•

• •∗

= =•

•• •

= = =

= =

+ −

= × ∆ − × ∆ −

∆ = ∆ + ∆ ∆ = ∆ + ∆

∑ ∑

∑ ∑ ∑

∑ ∑

b298K T

v

b

H

T

∆−�

�

bf p, ln

298KL V

TS S C

∆ = ∆ +

�

�

bp, ln

298KV

TC

�

fLS S∆ = ∆ �

fS∆ �

19

Indicators and Data Needs

• To generate a sustainability assessment a model musthave available data

• Data is not the final goal, but it is mandatory to getthere

• M & E flows , operating conditions and equipmentspecifications; substance properties: physicochemical,

20

specifications; substance properties: physicochemical,thermodynamic, and toxicity; manufacturing andcapital costs

• Data-source alternatives can be used to fulfill potentialdata gaps

– Simulators– Physiochemical– Toxicological

– QSAR models– Databases– Classification lists

Indicators and Data Needs:Efficiency

21

Indicators and Data Needs: Economic

22

Data Sources

Data source Property or type of provided data

DOT, TOXNET, ACToR

Hazardous material list

TRI program TRI PBT chemical listTOXNET/HSDB ERPG-2, ERPG-3, MW, ∆Hc, ρ, pH, KOW, Pv, Tflash, NFPA-r, NFPA-f,

IDLH, EC50, LC50, LD50, TWA

NIST Chemistry WebBook

MW, ∆Hr, Cp(T), ∆Hf, ∆Hc, ∆Hv,, Tflash, Pv(T), U, ∆Gr,

23

WebBookAIHA ERPG-2, ERPG-3ACToR MW, IDLH, LC50, LD50, ρ, KOW, Pv, MAK-CH, TWA, hazard, acute

toxicity, chronic toxicity, carcinogenicity, reproductive toxicity, neurotoxicity, immunotoxicity, dermal toxicity, respiratory toxicity, nephrotoxity, endocrine effects, ecotoxicity

ACToR/ICSC MW, EUclass, Rcode, NFPA, MAK-CH, Tflash, , µ, ECclass, TWA

IRIS MW, Pv, KOW, RfD, toxicity kinetics, pharmacokinetic modeling, hazard identification, mode-of-action and dose-response, cancer factors, and cancer descriptors

Sustainability Assessment: Biodiesel Case Study

• External data: ERPG, IDLH, Tb, Tm, LC50, etc.• Process data: m•i, in, m•i, out, CRM, CUT, Cequipment, etc.

• Definition of best & worst case scenarios

24

Biodiesel: Process Description

• Soybean oil• 95% Oil conversion• 1 Ton FAME/h• 99.60% Purity

• 0.1 Ton Glycerol/h• Utilities: steam, electricity,

cooling water• Solid, liquid, & air releases

Air Rel.H2O

300

305203

Oil

22 FAME

NaOH Re m oval

3

20

16

9

25

2

NaOH

Glycerol

303

304

200

202

MeOH

T-101

T-102

T-103

R-101

R-102

P-101

P-102

P-103

P-104

H-101

H-102

S-101

S-102

W-101Waste Oil

128

11

17

10

31H20 & MeOH

302

301

5

8

13

H3PO418

14

23

201

4

6

26

204

25

Environmental Indicator Results

20

40

60

80

1001. Nhaz. mat.

2.mhaz. mat.3.mhaz. mat. spec.

4.mPBT mat.5. CEI

6. HHirritation

7.HHchronic toxicity

8.SHmobility

9.SHfire/explosion

10.SHreac/dec I

11.SHreac/dec II

12.SHacute tox.

13.FTA

14.TRs

15.TR

16.EQ52.ms, tot.

53.ms, spec.

54.ms, recov.

55.ms, disp.

56.ws, recycl.

57.ws, nonrecycl.

58.ws, haz.

60.ms, haz. spec.

61.ms,nhaz.

62.ms, nhaz. spec.

63.Vl, tot.

64.Vl, spec.

65.Vl, nonpoll66.Vl, poll.

59.ms, haz.

Indicator Description Sust. (%)

1. Nhaz. mat.Number of hazardous

materials input40.00

6. HHirritationHealth hazard,

irritation factor99.31

10. SHreac/dec ISafety hazard, reaction

/ decomposition I97.00

22. EHbioacc.

Environmental hazard,

bioaccumulation (the

food chain or in soil)

98.34

0

16.EQ

17.EBcancer eff.

18. EHdegradation

19.EHair

20.EHwater

21.EHsolid

22.EHbioacc.

23.GWP

24.GWI

25.ODP

26.ODI

27.PCOP

28.PCOI

29.AP30.API

31.WPacid. water32.WPIacid. water

33.WPbasi. water34.WPIbasi. water

35.WPsalinity36.WPIsalinity

37.WPO2 dem.

38.WPIO2 dem.

39.WPtox. other

40.WPItox. other

41.WPtox. metal

42.WPItox. metal

43.EP

44.EPI

45.SMIM

46.MI M

47.ELR

48.EYR

49.ESI

50.BFM

51.RI

52.ms, tot.

food chain or in soil)

27. PCOPPhotochemical

oxidation (smog)

potential

99.83

32. WPIacid. waterAquatic acidification

intensity99.88

38. WPIO2 dem.Aquatic oxygen

demand intensity0.60

43. EPEutrophication

potential98.89

26

26

Efficiency Indicator Results

Indicator Description Sust. (%)

2. AEi Atom economy 90.60

7. MIv Value mass intensity 99.46

17. pROIMPhysical return on

investment99.76

Mass fraction of 20

40

60

80

1001. ε

2. AEi

3. AAE

4. SF

5. RME

6. mmat., tot.

23.Vwater, total.

24.FWC

25.WI

26.Φwater type

22.w recov. prod.

21. wrecycl. prod.

Mass fraction of

product from

recyclable materials

4.50

25. WI Water intensity 100

0

207. MI

8. MIV

9. MP

10.E

11.MLI

12.Emw

13.EMY14.CE

15.MRP

16. f

17.pROIM

18.RIM

19.BFM

20.w recycle. mat

21.w recycle. prod.

27

27

Energy Indicator Results

Indicator Description Sust. (%)

2. RSEISpecific energy

intensity99.49

6. ηE

Resource-energy

efficiency63.26

8. BFEBreeding-energy

factor53.38

10. ExExergy

92.59

20

40

60

80

1001. Etotal

2. RSEI

3. REI

4. WTE

13.RIEx

14.BFEx

12.ηEx

59.ms, haz.

10. ExtotalExergy

consumption92.59

14. BFExBreeding-exergy

factor100.00

0

5. SRE

6. ηE

7. RIE

8. BFE

9. Erecycl.

10.Extotal

11.REx

28

28

Economic Indicator Results

Indicator Description Sust. (%)

1. NPV Net present value 44.52

8. PBP Payback Period 81.10

19. COM Manufacturing cost 68.70

23. CE, spec. Specific energy costs 88.0720

40

60

80

1001. NPV

2. PVR3. DPBP

4. DCFROR

5. CCF

6. EP

7. ROI

8. PBP27.Cwater type

28.Cs tot.

29.Cs, spec.

30.Cl tot.

31.Cl, spec.

32.Cpur. air

33. Cpur. air fract.

33. Cpur. air fract.Fractional costs of

purifying air85.26

17.EPC

09. TR

10. CCP

11.CCR

12.Rn

13.REV

14. REVeco-prod

15.Ceq

16.TPC18.CTM

19. COM

20.CSRM

21.Cmat, tot.

22.CE, tot.

23.CE, spec.

24.CE, source

25.Cwater tot.

26.Cwater spec.

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29

GREENSCOPE.xlsm

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Stand Alone GREENSCOPE Software

• Currently in development

• Dr. Rajib Mukherjee (ORISE Post-Doc)

• JAVA Language• Based on the Excel® • Based on the Excel®

version• User can define

– level of interaction– which indicators to

calculate– best and worst case

scenarios

31

32

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Global Sustainability Assessment

• Impact assessment beyond the process to decide which design alternative is more sustainable based on the life-cycle considerations

• Identifying stages contributing greater than any other stage to the global life-cycle impact within the product life cycle

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Global Sustainability Assessment

A complete quantification of sustainability performancerequires an extensive evaluation of the entire systembeyond the manufacturing facility

35

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Conclusions

• Performance indicators for designing sustainable chemical processes at any level:– Provides direction to the designer (0% and 100% sustainability)– Modifying existing processes as well as implementing new chemistries– Approximates manufacturing scale sustainability from a bench or pilot

scale

• With GREENSCOPE, the results of sustainable • With GREENSCOPE, the results of sustainable chemical practices are quantified:– Modifications in the type and magnitude of goods and services– Preventing and minimizing all types of releases– Manufacturing the desired product without negatively affecting the

economic profitability

• GREENSCOPE can be used as a reliable and robust tool for the development of chemical processes

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References� Ruiz-Mercado, G. J.; Gonzalez, M. A.; Smith, R. L., Sustainability Indicators for

Chemical Processes: III. Biodiesel Case Study. Ind. & Eng. Chem. Res. 2013,

DisclaimerThe views expressed in this presentation are those ofthe author and do not necessarily represent the viewsor policies of the U.S. Environmental Protection Agency.

Chemical Processes: III. Biodiesel Case Study. Ind. & Eng. Chem. Res. 2013,DOI: 10.1021/ie302804x.

� Ruiz-Mercado, G. J.; Gonzalez, M. A.; Smith, R. L., Expanding GREENSCOPEbeyond the Gate: A Green Chemistry and Life-Cycle Perspective. Clean Tech. &Env. Policy 2012, DOI: 10.1007/s10098-012-0533-y.

� Ruiz-Mercado, G. J.; Smith, R. L.; Gonzalez, M. A., Sustainability Indicators forChemical Processes: II. Data Needs. Ind. & Eng. Chem. Res. 2012, 51, (5),2329-2353.

� Ruiz-Mercado, G. J.; Smith, R. L.; Gonzalez, M. A., Sustainability Indicators forChemical Processes: I. Taxonomy. Ind. & Eng. Chem. Res. 2012, 51, (5), 2309-2328.

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Thanks!

Questions?Questions?

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