Energy demand and carbon footprint of cheddar cheese with energy - - PowerPoint PPT Presentation

2nd International Conference on Sustainable Energy and Resource Use in Food Chains

RCUK Centre for Sustainable Energy Use in Food Chains

Energy demand and carbon footprint

• f cheddar cheese with energy

recovery from cheese whey

Piya Gosalvitr, Rosa Cuellar-Franca, Robin Smith and Adisa Azapagic

Sustainable Industrial Systems The University of Manchester

Paphos, Cyprus, 17-19 October 2018

Overview of cheese production and consumption

$124.20 billion by 2022 Cheese production in the UK World cheese producers

Cheddar production process

Pasteurisation Coagulation Milk 10 kg

Rennet 0.7 g Calcium chloride 1 g Saltpetra 3 g Whey 9 kg

Salt 20 g Cheddaring Curd cutting & whey drainage Pressing & packaging Storage Cheddar cheese 1 kg Packaging

Cheddar cheese whey

Ref : Carvalho et al., 2013, Cheese whey wastewater: Characterization and treatment

BOD: 27-60 g/l COD: 50-102 g/l

Ref : Carvalho et al., 2013, Cheese whey wastewater: Characterization and treatment

Anaerobic digestion Cheese whey 22.8 kg, Buffer solutions Biogas 1 m3 (55 % methane content)

Digestate 0.023 m3

Aims and objectives

• To assess the impacts of cheddar cheese with

energy recovery from whey through anaerobic digestion

• To identify the hotspots and make

recommendations for improvements

Methodology

• Process simulation

Cheese production process Aspen Plus

• Life cycle assessment

System boundary: cradle to grave Functional unit: 1 kg of cheddar cheese produced and consumed in the UK GaBi 8.6; Ecoinvent 3.3 Recipe 2016 impacts + primary energy demand

System boundary

Milk production at farm Regional Distribution Centre Retailer Home

T T T T

Anaerobic Digestion plant Combined Heat and Power Plant

Cheddar cheese factory

T

Landfill

Biogas Cheddar cheese

Electricity to grid Milk reception and storage Milk pasteurization Coagulation, Curd cutting, Cooking and Cheddaring Packaging and storage

whey Heat Electricity

Raw materials, Water, Chemicals and Energy

Wastewater

Emission Wastewater treatment plant

T = transportation

Aspen simulation

𝑈 = 4 ℃ 𝑈 = 30 ℃ 𝑈 = 68 ℃ 𝑈 = 38 ℃ 𝑈 = 90 ℃

Heat in integration r𝑓𝑒𝑣𝑑𝑓 𝑓𝑜𝑓𝑠𝑕𝑧 𝑑𝑝𝑜𝑡𝑣𝑛𝑞𝑢𝑗𝑝𝑜 = 4.46

𝑁𝐾 𝑙𝑕 𝑑ℎ𝑓𝑒𝑒𝑏𝑠

1.74 4.92 3.82 3.83 0.82 1.38 1 2 3 4 5 6 7 8 9 10 Kim et al. Aguirre-Villegas et al. This study Energy (MJ/kg) Electricity (grid) Thermal energy (unspecified source) Electricity (whey biogas) Heat (whey biogas)

Energy sources: comparison with the literature

4.46

Energy reduction from heat integration

Energy flow in the cheese factory

Cheese production process Anaerobic digestion Combined heat and power CHP efficiency: 85 % (39 % for electricity, 46 % for heat) 1.38 MJheat 0.62 MJheat 0.82 MJelec. 0.12 MJelec. Heatcredit: 1.58 MJ Electricity credit: 2.1 MJelec. Heatproduced: 3.58 MJ Electricityproduced: 3.04 MJelec.

Cheddar cheese whey Biogas

Carbon footprint

9.43 0.17 0.41 0.09 1.54 0.22 0.04 11.89 0.42 0.23 0.16

• 0.53
• 0.40

11.78

• 2

2 4 6 8 10 12 14 Carbon footprint (kg CO2 eq./kg)

9.43 0.17 0.12 0.09 1.54 0.22 0.04 0.33 0.23 0.16

• 0.37
• 0.18

11.78

• 2

2 4 6 8 10 12 14 Carbon footprint (kg CO2 eq./kg)

Primary energy demand

55.50 2.71 6.97 0.63 23.03 3.55 0.50 92.89 4.85 1.31 0.67

• 9.20
• 3.82

86.70

• 20

20 40 60 80 100 Primary energy demand (MJ/kg) 55.50 2.71 3.02 0.63 23.03 3.55 0.50 3.82 1.31 0.67

• 6.35
• 1.69

86.70

• 20

20 40 60 80 100 Primary energy demand (MJ/kg)

Conclusions

• The main contributor to carbon footprint and primary

energy demand

– milk production (80% and 64%) – refrigerated storage at retailer (13% and 27%)

• Heat integration in the production process can decrease

total life cycle energy demand by 5%

• Whey digestion makes the cheese process energy self-

sufficient

• It reduces the total carbon footprint by 5% and primary

energy demand by 10%

Acknowledgements

Royal Thai Government Scholarship

 This work is a part of Ph.D. thesis “Sustainability Assessment of Technologies for Energy Saving and Recovery in the Food Industry”

2nd International Conference on Sustainable Energy and Resource Use in Food Chains

RCUK Centre for Sustainable Energy Use in Food Chains

Energy demand and carbon footprint of cheddar cheese with energy recovery from cheese whey

Piya Gosalvitr, Rosa Cuellar-Franca, Robin Smith and Adisa Azapagic

The University of Manchester

Paphos, Cyprus, 17-19 October 2018