Appendix A: Tables Showing GibbsFree Energy as a Function of Temperatureof Formation Reactions

Table A.1 Gibbs free energy of methane formation at differ-

ent temperatures (Adapted from David 2012)

C + 2H2!CH4

T (K) ΔG (kJ/mol)

298.15 �50.53

300 �50.381

400 �41.827

500 �32.525

600 �22.69

700 �12.476

800 �1.993

900 8.677

1000 19,475

1100 30.358

1200 41.294

1300 52.258

1400 63.231

1500 74.2

Table A.2 Gibbs free energy of ethane formation at different

temperatures (Adapted from David 2012)

2C + 3H2!C2H6

T (K) ΔG (kJ/mol)

298.15 �32.015

300 �31.692

(continued)

© Springer International Publishing Switzerland 2017

J.L. Silveira (ed.), Sustainable Hydrogen Production Processes, Green Energy

and Technology, DOI 10.1007/978-3-319-41616-8

177

Table A.2 (continued)

2C + 3H2!C2H6

T (K) ΔG (kJ/mol)

400 �13.473

500 5.912

600 26.086

700 46.8

800 67.887

900 89.231

1000 110.75

1100 132.385

1200 154.096

1300 175.85

1400 197.625

1500 219.404

Table A.3 Gibbs free energy of ethanol formation at different

temperatures (Adapted from David 2012)

2C + 3H2 + 1/2O2!C2H5OH

T (K) ΔG (kJ/mol)

298.15 �167.874

300 �167.458

400 �144.216

500 �119.82

600 �94.672

700 �69.023

800 �43.038

900 �16.825

1000 9.539

1100 36

1200 62.52

1300 89.07

1400 115.63

1500 142.185

Table A.4 Gibbs free energy of carbon dioxide formation at

different temperatures (Adapted from David 2012)

C +O2!CO2

T (K) ΔG (kJ/mol)

298.15 �394.373

300 �394.379

400 �394.656

500 �394.914

600 �395.152

(continued)

178 Appendix A: Tables Showing Gibbs Free Energy. . .

Table A.4 (continued)

C +O2!CO2

T (K) ΔG (kJ/mol)

700 �395.367

800 �395.558

900 �395.724

1000 �395.865

1100 �395.984

1200 �396.081

1300 �396.159

1400 �396.219

1500 �396.264

Table A.5 Gibbs free energy of carbon monoxide formation

at different temperatures (Adapted from David 2012)

C + 1/2O2!CO

T (K) ΔG (kJ/mol)

298.15 �137.168

300 �137.333

400 �146.341

500 �155.412

600 �164.48

700 �173.513

800 �182.494

900 �191.417

1000 �200.281

1100 �209.084

1200 �217.829

1300 �226.1518

1400 �235.155

1500 �243.7424

Table A.6 Gibbs free energy of water formation from carbon

at different temperatures (Adapted from David 2012)

H2 + 1/2O2!H2O

T (K) ΔG (kJ/mol)

298.15 �228.582

300 �228.5

400 �223.9

500 �219.05

600 �214.008

700 �208.814

800 �203.501

(continued)

Appendix A: Tables Showing Gibbs Free Energy. . . 179

Table A.6 (continued)

H2 + 1/2O2!H2O

T (K) ΔG (kJ/mol)

900 �198.091

1000 �192.603

1100 �187.052

1200 �181.45

1300 �175.807

180 Appendix A: Tables Showing Gibbs Free Energy. . .

Appendix B: Adaptation of Carduand Baica’s Methodology

As it is proposed by Cardu and Baica (1999), it is assumed that the ecological

efficiency has the following form:

ε ¼ c � φ η, indicadorð Þ � ψ indicadorð Þ½ �n

Constant “c” and the exponent “n” are going to be calculated by the boundary

conditions. The Pollutant Indicator is used to quantify the environmental impact of

a technology. Its unit is kgCO2(eq)/kgH2.

By following the concepts of the authors, it is proposed that φ(η, indicator) is asfollows:

φ ¼ ηsystemηsystem þ indicator� �

where ηsystem is the efficiency of the hydrogen production system.

In order to reduce the range of values and approximate the efficiency curves of

various technologies, the authors propose using function ψ�indicator ) as

ψ ¼ ln K � indicatorð Þ. As the logarithm transforms a high number into a lower

number, the distance between extreme points is attenuated. For example, ln

10¼ 2.3 and ln 100¼ 4.6. Therefore, an interval of [10–100] became [2.3–4.6].

In order to validate the equation, three boundary conditions are adopted, which

are different from those defined by Cardu and Baica and with the indicator in

kgCO2(eq)/kgH2:

Condition 1. If the indicator¼ 0, ε ¼ 1 for any η.Condition 2. If the indicator¼ 50 kgCO2 eqð Þ=kgH2, ε ¼ 0 for any η. This indi-

cator corresponds to the impact of Lignite (coal with high carbon content).

© Springer International Publishing Switzerland 2017

J.L. Silveira (ed.), Sustainable Hydrogen Production Processes, Green Energy

and Technology, DOI 10.1007/978-3-319-41616-8

181

Condition 3. In this case, the hydroelectric power plant was adopted because

the ecological efficiency of this hydrogen production process has already

been previously calculated by Braga (2010), Siqueira and Silveira (2011),

which corresponds to 0.99. It is obtained the indicator¼ 0.34 kgCO2(eq)/kgH2

and η ¼ 0:78 (value calculated for the hydrogen production process with

electricity from a hydroelectric power plant).

If:

ψ ¼ ln K � indicatorð Þ

Thus, through condition 2 and formulation 1, it is obtained:

ψ ¼ ln 51 � indicatorð Þ

consequently:

ε ¼ c � ηsystemηsystem þ indicator� � � ln 51� indicatorð Þ

" #n

From condition 1, it is found that

1 ¼ c � ln 51ð Þ½ �nThen c¼ 0.25

From condition 3, it is found that n¼ 0.023 for ε ¼ 0:99n and the ecological

efficiency equation for hydrogen production process is written as:

ε ¼ 0:25 � ηsystemηsystem þ indicator� � � ln 51 � indicatorð Þ

" #0:023

where:

Indicator: [kgCO2(eq)/kgH2]

References

Braga LB (2010) Analise economica do uso de celula a combustıvel para acionamento de onibus

urbano. Dissertation—Curso de Engenharia Mecanica, Departamento de Energıa, UNESP,

Guaratingueta

Cardu M, Baica M (1999) Regarding a global methodology to estimate the energy-ecologic

efficiency of thermopower plants. Energy Convers Manage 40:71–87

David R (2012) CRC handbook of chemistry and physics, 87th edn. Internet version 2007

Siqueira RBP, Silveira JL (2011) Eficiencia ecologica aplicada a uma PCH em func~ao da operac~aode um reservatorio hipotetico. PCH Notıcias e SHP News 50:24–28

182 Appendix B: Adaptation of Cardu and Baica’s Methodology

Index

AAlgae growth, 104, 105

Annuity factor, 109–111

BBelo Monte hydroelectric power plant

project, 140

Biocrude, 154

Biogas, 77, 79, 82, 84–86, 88, 90, 92, 94, 95,

99–100, 106, 107, 111, 115, 124, 175, 176

ecological efficiency, 175

steam reforming process, 133–134, 136

Biological hydrogen production, 155

Biophotolysis, 155

Brazil, 104, 111

Brazil’s energy policy, 145, 147, 148, 171

Brazilian conditions, 145, 149, 152, 157,

162, 168, 171

CCarbon cycle, 130, 131, 136

Carbon dioxide (CO2), 127, 128, 130–133,

135, 136, 159

Carbon monoxide, 151, 152, 154

Chemoheterotrophic species, 154

Closed reactors, 105

Coal gasification, 159, 165, 166, 168

DDegree of advancement (α), 2, 78, 87–94Direct ethanol fuel cells (DEFC), 150

Dry reforming reactions, 99

EEcological efficiency

electrolysis, 134–135

hydrogen production from microalgae,

135–136

steam reforming process, 129–134

Economic analysis, 111–124

Economic indicators, 162–163

Economical comparison, 123–124

Electrolysis, 2, 128, 135, 136, 153

Electrolytic process, 116–120

electrolysis using hydroelectric power, 103

electrolysis using solar energy, 103

electrolyzer, 102

using wind power, 102

Electrolyzer, 101–103, 109, 110, 116, 124

Endothermic process, 87

Environmental analysis, 127, 128

Environmental indicators, 161–162

Eolic energy, 135

Equilibrium constant (K ), 2, 77, 78, 87,

89, 91, 92

Ethanol fuel car, 149

Ethanol industry, 146

FFossil fuels, 142, 147, 153, 154, 157, 159,

160, 162, 165, 166, 168, 169

Fuel cell program, 150

GGas emissions, 127

Gasification, 154, 159

© Springer International Publishing Switzerland 2017

J.L. Silveira (ed.), Sustainable Hydrogen Production Processes, Green Energy

and Technology, DOI 10.1007/978-3-319-41616-8

183

GHG emissions. See Green house gas (GHG)

emissions

Gibbs free energy

reforming process and shift reaction,

82–86

change as function of temperature, 79–94

degree of advancement, 87–94

equilibrium Constant, 87

Gibbs free energy change (ΔGo), 77

Global sustainable development, 141

Global warming potential (GWP), 128

Green house gas (GHG) emissions, 143,

165, 167

Group of optimization of energy systems

(GOSE ), 170

HH2 production process, 100

Hydraulic power, 165

Hydroelectric power, 103, 128

Hydroelectric power plants, 135, 136

Hydrogen, 1–3

production from algae, 104–106, 176

production from microalgae, 104

production process from algae,

121–124

storage and distribution, 155–156

Hydrogen cost, 109–124, 175

Hydrogen from biological processes

(biophotolysis) (HBP), 159

Hydrogen from coal gasification with

carbon capture (HCGCC), 159

Hydrogen from electrolysis powered by

renewable sources (HEPRS), 159

Hydrogen from the steam reforming of

ethanol (HSRE), 160

Hydrogen from the steam reforming of

natural gas (HSRNG), 160

Hydrogen production, 128, 134, 136

bacteria/algae, 165

biological processes, 154–155

in Brazil, 146–156

electrolysis, 153

fuel cells, 150, 152, 165

pipelines, 155

process, 166

pyrolysis/gasification, 154

steam reforming of ethanol, 152–153

steam reforming of natural gas, 151–152

technologies in Brazil, 139–147, 149–152,

154–163, 166, 168–171

Hydropower, 147

IIndicators

economic, 162–163

environmental, 161–162

social, 163

weighting of criteria/indicators, 164

Interest rate, 111–123

Internal combustion engines (ICE), 151, 168

Investment costs, 124

LLaboratory for optimization of energy

systems (LOSE), 79, 111

Life cycle assessment (LCA), 128, 145

Lower heating value (LHV), 96–100

MMaintenance cost, 109, 110, 124

Methane, 159

Microalgae, 135–136

Microwave plasma reforming, 101

Microwave plasma sources (MPSs), 101

Multi-criteria analysis (MCA), 139, 143–145,

156–158, 160, 161, 166, 168, 170, 171

NNatural gas (NG), 77, 79, 82, 83, 85, 86, 88, 90,

91, 93–95, 97–99, 101, 106, 107, 111,

113, 114, 124, 160, 165, 175

steam reforming process, 131–132, 136

National Renewable Energy Laboratory

(NREL), 116

OOrganisation for Economic Co-operation and

Development (OECD), 148

Operation cost, 109, 110, 116, 124

Operation time, 111–113, 115–120, 122, 123

PPayback period, 112, 114, 115, 117, 119,

120, 122

Performance matrix, 163

Photobiological process, 175

Photofermentation, 154

Photosynthesis process, 104

Photovoltaic

energy, 135

184 Index

power, 117–119, 128

power plants, 134

Physicochemical analysis, 77–79, 82, 94, 95

Plasma reforming, 100–101

Pollutant indicator, 128, 129, 135, 136

Potential to emit (PTE), 165

Proalcohol program, 149

Proton exchange membrane fuel cell

(PEMFC), 153

Pyrolysis, 154

RRenewable energy, 146–156

Renewable fuels, 147–150

Revamping power generation, 157

SS~ao Paulo, 158

Sensitivity analysis, 168

Shift reaction process, 77, 79, 84, 86,

87, 89, 91, 92, 95

Social indicators, 163

Solar energy, 103

Solar hydrogen energy system, 142

Solar power, 116

Solar spectrum, 104

Steam reforming process

biogas, 133–134, 136

ethanol, 152–153

natural gas, 131–132, 136, 151–152,

168, 169

Steam reforming processes

ecological efficiency, 129–134

ethanol, 129–131, 136

Stoichiometric equations, 129–133

Stoichiometry, 82, 94, 96–99

Sugar cane bagasse, 129–132, 136,

146, 147, 149, 154, 170

Sulphur dioxide (SO2), 127, 130–134

Sustainability

assessment, 161–163

indicators, 139, 141, 145, 146, 160,

161, 165

Sustainable fuel, 142, 156–158

Syngas, 154

TThermochemical process

Gibbs free energy (G), 79–94

physicochemical analysis, 77–78

plasma reforming, 100–101

steam reforming of biogas, 99–100

steam reforming process, 94–95

thermodynamic efficiency, 95–99

Thermodynamic

analysis, 2, 77–79, 82, 87, 89, 92, 94–97,

99–102, 104–107

efficiency, 77, 95–100, 102, 105–106,

135, 175

function, 77

WWater electrolysis, 153

Water spillage, 135

Water-gas shift reaction, 152

Water-gas shift reactor, 129Wind power, 102, 116–118, 128, 136

Wolfram Mathematica software, 89

World Commission on Environment and

Development, 156

Index 185