Gestão de Energia : 2013/14

Gestão de Energia: 2013/14

Class # 4

Energy Analysis: Block diagrams

Prof. Tânia [email protected]

• Embodied Energy is …

Embodied EnergyMaterial Energy MJ per kg

Bricks (common) 3

Steel (general, av. recycled content) 20.1

Stainless steel 56.7Cork insulation 26

Aluminium (general & incl 33% recycled) 155

PVC (general) 77.2Wallpaper 36.4

Iron (general) 25

Copper (average incl. 37% recycled) 42

Lead (incl 61% recycled) 25.21Ceramic sanitary ware 29

Paint - Water-borne 59Paint - Solvent-borne 97

• Embodied Energy is the sum of all the energy required to produce any goods or services,

Embodied Energy

L ifec yc le E ner gy (M J /k g)

F o od G rou p

S w ed en U K M eat from la n d 13-75 45 - 10 9 M eat from o cea ns 19 -22 0 75 - 15 0 C h eese 60-65 75 E gg s 18 58 M ilk 5-6 7 -8 L e gu m e s 5 -20 22 -33 O th er Veg eta b le s 11 -60 9- 35 F ru it , u n sp ecif ie d 9- 31 F ru it , a ir fre igh t 29 -11 5 F ru it , sh ip 9 -10 F ru it , loca l 5 B re ak fast c erea ls 2 .5-37 25 C erea ls 2 -7 .5 10 -25 B re ad s 9 -21 10 S w ee ts 1 -44 13 - 19 0

Energy Analysis

Auto-industry assembly line

Electricity

Paint

Embodied energy in a car?

Energy Analysis

• Definition: the process of determining the embodied energy of a product or service, i.e., the energy required directly and indirectly to produce it

– The energy used indirectly might be more important that the energy used directly

Auto-industry assembly line

Electricity

Paint

Embodied energy in a car: 270 GJ

Energy Analysis

• What is Energy Analysis useful for:

Energy Analysis

• What is Energy Analysis useful for:– Determine the energy needed to produce a product– Compare the energy needed to produce a product in

different places

– Compute energy savings due to changes in the production processes, e.g., by recycling waste glass produced inside a glass factory back to the furnace?

Energy Analysis

• Difficulties associated with the Energy Analysis framework:

Energy Analysis

• Difficulties associated with the Energy Analysis framework:– Choosing the system boundary

– Merge several kinds of energy• Ex: the production of fueloil from crude oil has a much higher

efficiency than the production of electricity from coal

– Energy Credit for by-products• Ex: by-products from the iron & steel industry are used by the cement

industry

Energy Analysis: Basic Operations

• Unitary Production Operation

• Conventions:– The use of block letters for Operations– The use of numbers for Inputs/Outputs

Operation Am2

m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

Energy Analysis: Specific Consumption of Operation & Inputs

• Specific Consumption of Operation A: CEA

• Specific Consumption of Material 1: CE1

3

Energy consumption of operation A /Production of operation A

AA

ECE kJ kgm

11 1

1

Energy consumption in previous operations /Mass of 1

ECE kJ kgm

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

Energy Analysis: Mass Factors

• Residue formation factor

• Mass proportion

1 2

3

Materials input of A= ( 1)Production of A

A Am mS Sm

11

1 2

Material input of 1 in A ( 1 1)Total materials input of A i i

i

mf f e fm m

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

Energy Analysis: Specific Consumption of Production

• What is the energy specific consumption of m3?

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1



• Write it as

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

3 A 1 23

3 3

E E +E +ECE = =m m

3 3 1 2 1 2, , , , ,A ACE CE CE CE CE S f f

A 1 2A 1 2

3 1 2

1 2 1 2A 1 2

3 1 2 1 2

E E ECE ; CE ; CEm m m

m m m mS ; f ; fm m m m m



• Write it as

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

3 A 1 23

3 3

E E +E +ECE = =m m

3 3 1 2 1 2, , , , ,A ACE CE CE CE CE S f f

A 1 2 1 1 2 23 A 1 1 2 2

3 3 1 2 1 1 2 2

E m m m E m ECE CE CE CEm m m m m m m m AS f f

A 1 2A 1 2

3 1 2

1 2 1 2A 1 2

3 1 2 1 2

E E ECE ; CE ; CEm m m

m m m mS ; f ; fm m m m m

Direct Energy Use

Indirect Energy Use



• What is the specific consumption of residues?

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

3 A 1 23

3 3

E E +E +ECE = =m m



• The specific consumption of residues is null

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

3 A 1 23

3 3

E E +E +ECE = =m m

No energy consumption is attributed to mR (which is also an output of operation A)



– Why does a higher residue formation factor, SA, implies a higher specific consumption of the useful output, CE3?

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

3 A 1 23

3 3

E E +E +ECE = =m m

3 A 1 1 2 2CE CE CE CEAS f f

Energy Analysis: Sequential Process

• What is the energy specific consumption CE4?

BA C2 3 41

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

EA EBEC



• Write it as a function of:

BA C2 3 41

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

EA EBEC

4 3C CCE CE S CE

4 4 1, , , , , ,C C B B A ACE CE CE S CE S CE S CE



BA C2 3 41

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

EA EBEC

2

3

CE

4 C B A 1

CE

CE CE CE CEC B ACE S S S


• What is the energy specific consumption CE4

using this exterior boundary?

BA C2 3 41

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

EA EBEC


• What is the energy specific consumption CE4

using this exterior boundary?

• Homework: Prove that this expression is equal to

BA C2 3 41

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

EA EBEC

4 14

4 4

A B CE E E E ECEm m

4 C B A 1CE CE CE CEC B ACE S S S

Exercise

Consider the production system of floor pavement that has only: a ceramic oven, choice of defective parts and storage. The specific consumption of the furnace is 200 kJ / kg, whereas the specific energy consumption of the choice operation is 5 kJ / kg and the specific energy consumption of storage operation is 20 kJ / kg. The floor raw material involved an energy consumption of 50 kJ / kg in the clay processing operations. The operation of cooking promotes the volatilization of certain components of raw pavement representing 5%. The operation of choice rejects 10% of the output of the furnace and breaks during storage are 1%. Determine the specific consumption of the floor pavement.

Exercise

Scheme

CEA = 200 kJ/kg; CEB = 5 kJ/kg; CEC = 20 kJ/kgCE1 = 50 kJ/kg;SA = 1/0.95; SB = 1/0.9; SC = 1/0.99

ChoiceOven Storage2 3 41

EA EBEC

4 C B A 1CE CE CE CE 308kJ/kgC B ACE S S S

Energy Analyis: Convergent Process


A

B

C 54

2

3

1

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

Energy Analyis: Convergent Process


5 2 2 4 4

2 1

4 3

C C

A A

B B

CE CE S f CE f CECE CE S CECE CE S CE

A

B

C 54

2

3

1

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

Exercise

A company manufacturing sunflower oil imports 60% of raw material and the remaining 40% is domestically produced. The sunflower imported is transported by sea 1000 km, while the national sunflower is transported by truck 200 km. The operation of oil refining has a specific consumption of 100 kJ/kg. The oil content of sunflower is 10%, meaning that the rejection mass on refining is 90% (in fact thismaterial is used in the manufacture of cattle feed). The specific consumption of transport is 0.025 kJ/kg.km by truck and 0.010 kJ/kg.km by sea. Losses in sunflower transportation are 1% on truck and 0.1% on ship. Determine the specific consumption of refined oil.

Exercise

Scheme

CEA =10000.01 kJ/kg; CEB =2000.025 kJ/kg;CEC =100 kJ/kg;SA = 1/0.999; SB = 1/0.99; SC = 1/0.1;CE1 = CE3 = 0;

A: Transportship

B: Transporttruck

C: Refining 5

4

2

3

1

5 2 1 4 3 180kJ/kg C C A A B BCE CE S f CE S CE f CE S CE

Energy Analyis: Divergent Process

• In a divergent process all products that are an output of the same operation have the same specific energy consumption– There are other options to give energy credit to by-

products, e.g., economic.

B

C

A

3

5

2

41

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1


• What are the energy specific consumptions

CE5 & CE3?

B

C

A

3

5

2

41

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1


• What are the energy specific consumptions

CE5 & CE3?

B

C

A

3

5

2

41

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

3 B 2

2 A 1

CE CE CE CE CE CE

B

A

SS

5 C 4

4 2

CE CE CE CE CE

CS

Exercise

• Compute CE11 and CE12

DE

C

GA 11109

75

2

F

1

4 B

3

6

128

Exercise

• Compute CE11 and CE12

DE

C

GA 11109

75

2

F

1

4 B

3

6

128

11 G 10

10 E 9

9 D 1 1 6 6 7 7

6 B 4

4 A 2

7

CE CE CE CE CE CE

CE CE f CE f CE f CE

CE CE CE CE CE CE

CE

G

E

D

B

A

SS

S

SS

C 3 3 5 5 5 4

12 F 8

5 4

CE f CE f CE CE CE

CE CE CECE CE

C

F

S

S

Energy Analysis: Treatment Operation


• Energy consumption in a treatment operation is assigned to the operation that generates the residues (A)

Operation Am1 m2

mR

EA

Materialsinput

Production

Energyconsumption

Residues

Treatment operation B

m3

Recycledresidues EB

Energy consumption in treatment



Operation Am1 m2

mR

EA

Materialsinput

Production

Energyconsumption

Residues


m3

Recycledresidues EB


2 A 1 B2 A 1

2 2 2

t BB

R

t2 A 1 B

E E E E ECE CE S CEm m m

Energy in B E CE Residues of A mResidues of A S S S 1

Production of ACE CE S CE S CE

t tB

A

t

t tA A A

tA A




Operation Am1 m2

mR

EA

Materialsinput

Production

Energyconsumption

Residues


m3

Recycledresidues EB


2 A 1 B2 A 1

2 2 2

t BB

R

t2 A 1 B




t tB

A

t

t tA A A

tA A



• What is the energy specific consumption CE3?– The energy specific consumption of the output

from the treatment operation is null

Operation Am1 m2

mR

EA

Materialsinput

Production

Energyconsumption

Residues


m3

Recycledresidues EB


2 A 1 B2 A 1

2 2 2

t BB

R

t2 A 1 B




t tB

A

t

t tA A A

tA A

Energy Analysis: Recycling

• What is the specific consumption of production CE2?

Operation Am1 m2

mR

EA

Materialsinput

Production

Energyconsumption

Residues


m3

Recycledresidues

EB

Energy consumption in treatmentRecycling

operation C

m4

Energy Analysis: Recycling

• What is the specific consumption of production CE2?

• Other recycling schemes:

Operation Am1 m2

mR

EA

Materialsinput Production

Energyconsumption

Residues


m3

Recycledresidues

EB

Energy consumption in treatmentRecycling

operation C

m4

2 A 1 42

2 2

t2 A 1 1 4 4 B

4 3

3

E E E E ECEm m

CE CE S f CE f CE S CE

CE CE0

tB

tA A

D DS CECE

Exercise

• Compute CE6

B

3

C(treat)

D

A

4

R

6

1

25

Exercise

• Compute CE6

B

3

C(treat)

D

A

4

R

6

1

25

6 B 2 2 5 5

5 A 1 1 4 4 A

4 D 3

3

CE CE f CE f CE

CE CE f CE f CE CE CE CE CE CE 0

B

t tA C

D

S

S SS

Energy Analyis: Energy & material inputs

• What is the meaning of E1?– E1 is the total energy used to produce m1

• For consistency purposes what should be the meaning of EA?

Operation Am2m3

mR

EAMaterials

lnput Production

Energyconsumption

Residues

m1

Energy Analyis: Energy & material inputs

• What is the meaning of E1?– E1 is the total energy used to produce m1

• For consistency purposes what should be the meaning of EA?– EA should be the total energy used to produce that

energy consumption, i.e., EA should be the primary energy associated with the final energy input

– To merge several kinds of final energy first convert each one to primary energy and then make the sum

Energy Analyis: Energy efficiency measures

• What is the impact of an energy efficiency measure that decreases CEA on CEoutput?

BA C2 3 41

EA EBEC

6

Energy Analyis: Energy efficiency measures

• What is the impact of an energy efficiency measure that decreases CEA on CEoutput?

BA C2 3 41

EA EBEC

4 3

3 2

2 1

2 3 4

A A A

CE CE CECE CE CECE CE CE

CE CE CE1; ;CE CE CE

C C

B B

A A

B C B

SSS

S S S

Exercise

A factory produces 2 end products: P1 and P2. These products follow the production process shown in the diagram below, with P1 = 50000 ton/year and P2 = 30000 ton/year. The operation G treats the effluents from E and F. These two (E and F) are the only productive operations that generate waste, and SE = 1.2, SF = 1.3. In operation G, only 20% of the input effluent, exits the process as waste. The values of composition are as follows: f4 = 0.4, f6 = 0.5. The table presents the specific consumption of each operation. Consider that for electricity: 0.215 kgep/kWh and for fueloil 0.984 kgep/kg.

Calculate f13

8 (produção 1)

A

C

D

E

B

2

1

F

G

1413

1211

10 (produção 2)

3

4

5

6

7

9

Exercise

8 (produção 1)

A

C

D

E

B

2

1

F

G

1413

1211

50000

30000

30000

30000

3000010000

39000

9000

380015200

27600

4140041400

42400

1315200 26%57600

f

Exercise


What is the specific consumption of each operation?

A B C D E F G H

Electricidade (kWh/ton produto) 100 20 30 20 20 20

Thick Fuel Óleo (kg/ton produto) 50 60 50

Exercise

CE = 100 0.215+50 0.984 kgoe

CE = 20 0.215 kgoe

CE = 30 0.215 kgoe

CE 20 0.215 kgoe

CE 60 0.984 kgoe

CE = 20 0.215 kgoe

CE = 20 0.215 kgoe

A

B

C

D

E

F

G

Exercise


What is the specific consumption of each product?

8 (produção 1)

A

C

D

E

B

2

1

F

G

1413

1211

10 (produção 2)

3

4

5

6

7

9

Exercise

t t8 E E 6 6 7 7 E G

6 C 3

3 4 13 13 1 1

13

1

7 9 4 4 5 5

5 2

2

t t10 9 G

CE =CE +S f CE +f CE +S CE

CE =CE +CE

CE =CE =CE + f CE +f CE

CE 0CE 0

CE =CE =CE + f CE +f CE

CE =CE +CECE 0

CE =CE +S CE +S CE

A

D

B

F F F

Exercise


In which product will a measure of energy savings implemented in the operation A reduce more the specific consumption?

8 (produção 1)

A

C

D

E

B

2

1

F

G

1413

1211

10 (produção 2)

3

4

5

6

7

9

Exercise

8 10E 6 7 4 4

6 C 13 13 1 1

t t8 E E E G4 13 13 1 1

7

5 2

10 4 13 13 1 1 5 2

t tG

S f +f f S f

f CE +CE + f CE +f CE +

CE =CE +S +S CEf CE + f CE +f CE +f CE +

f CE +CE

CE =CE +S CE + f CE + f CE +f CE +f CE +CE

+S CE

FA A

A

AD

B

F F D A B

F

CE CECE CE

Documents

Gestão de Energia : 2013/14