1. Cost & Carbon Saving Opportunities in the Food & Allied Industry
Doug Marriott
BSc CEng CSci FIEE FIET FInstR MInstPet MEI FIFST FRSA
Chartered Engineer  - Chartered Scientist
Director Doug Marriott Associates Ltd
Tel +44(0) Mob +44(0)

2. Agenda Waste Statistics Co- Tri Polygeneration
GQCHP – Good Quality CHP
Commercial Considerations for use of CHP
Applications
Some Examples and Site Details
Sorption Systems
Commercial Example ~ Funding Grants
Concluding Remarks

3. Some Food Industry Statistics
Major user of energy ~ 100TWh which is equivalent to 11% of energy use by business 7.9 Million tonnes Carbon p.a. Significant waste stream ~ accounting for 10% industrial & commercial waste Refrigeration is a significant polluter in terms of refrigerant leakage (Can be >25% energy CO2 equivalent in some sectors) Landfill waste costs rising annually -current cost typically £93/t overall

4. Waste Figures in the UK 19 million tonnes food waste (+/- 5%)
6.7 million tonnes household food waste
4.1 m t / p.a. food manufacture
3.0 m t / p.a. food service & restaurants
1.6 m t / p.a. retail food
3.6 m t / p.a. remainder ~ horticulture,
agriculture, schools,
hospitals.
Source

5. Defra Backs Anaerobic Digestion
Organic Materials - Manure Slurry Food waste - could be source of 2 MWhe Source UK Gov. - Jane Kennedy Farming & Environment Minister
Defra indicate the UK produces >100Mtonnes of organic waste (90 M tonnes from manure)
Defra launching Task force - To Assist sectors such as Farming , Water Industry, Food Industry to produce biogas
NFU target to have 1,000 on farm units by 2020 to power farms and have fertilisers as a byproduct

7. Definition of Polygeneration
CHP is the simultaneous production of Heat & Power derived from a single or multiple source of fuel/energy. Polygeneration is the use of multiple energy inputs to create multiple energy outputs.

8. Why Trigeneration Embedded Power Trigeneration?
Grid Power Conventional

9. Grid Supply Energy Efficiency Limitations
Grid electrical efficiency use on site is limited to the power station efficiency minus distribution losses e.g. 40% - 4% = 36% (Max Available) The waste heat from the power stations have historically not been captured / used waste energy. CHP has opportunities to use this waste energy and can accordingly improve the thermal efficiency on applications compared to grid electrical supply reaching efficiencies of =>80%

10. Conventional Systems ή Power station 40-45% ή transmission = - 3%
ή Power to site = %
ή Loss = 63% – 58%
2/3 energy is lost

11. Conventional Systems Energy Act - 80% reduction in energy use by 2050
ή Power station 40-45%
ή transmission = - 3%
ή Power to site = %
ή Loss = 63% – 58%
2/3 energy is lost
Energy Act - 80% reduction in energy use by 2050
How can we achieve it !

12. The key design Good Quality CHP (GQCHP)
The target energy usage should ideally have a ratio of heat/power requirements, which are as closely in phase with the ratio of heat and power delivered by the CHP plant through all the production capacities / demand. The Measure is Good Quality CHP ( My Rule of thumb) Index = 200 Electrical Efficiency Thermal Efficiency > 100 GQCHP Avoids payment of climate change levy (CCL)

13. CHP the Success Criteria
Continuous and matched heat & electrical supply & demand Suitable ratio of energy demand/supply Currently Spark Gap (electrical cost / fuel cost) > 3.0 CO2 emission reduction – Tax advantages Improved security of supply Interruptible energy supply cost savings - supply security Suitable relative capital incentive – mains supply Relative maintenance costs not a significant penalty Projected life cycle costs are attractive compared to conventional.

14. Some Applications of CHP
The plant electrical or part load supply plus
Water/Fluid heating – Process industry, adjacent
heating, space heating, food cooking/ pasteurisation
Steam raising – district heating, process heating
CO2 + electricity + heat for horticulture
Drying - direct – milk, process
- indirect – waste sludge,
- secondary processes

15. Actual Deliveries of CHP Systems by a Leading Supplier

16. Commercial Considerations for Successful CHP Applications
e.g.
Electricity £0.010/kWh : Gas £0.030 /kWh
Rule of thumb Spark Gap > 3.0
Relative cost of power / fuel ~ Electricity to Gas
Cost of electricity - gas ~ Price Gap = 7.0 p/kW
Cost of electricity / gas ~ Spark Gap = 3.3
Electricity Connection Charge and agreements
Gas Connection charge and agreement
Potential to manage interruptible gas supplies

17. The Prime Movers There is a variety of available systems that
can be applied as the electrical primary energy
Supply devices. E.g.
Reciprocating Engines
Microturbines
Gas Turbines
Steam Turbines
Solar
ORC (Organic Rankin Cycle)
Fuel Cells

18. Some fuels used in prime movers
Natural Gas (including interruptible supplies, CNG)
Wellhead Gases
LPG (liquid and gaseous)
Naphtha
Landfill and Sewage Gas
Mines Gas (Coal Bed Methane)
High Hydrogen Gases
Coke oven gas
Synthetic Gases from biomass, coal and wastes
Gasified (‘wood & waste food gas’)
Diesel, Kerosene & biofuels
Crude Oil
Waste solvents e.g. ethanol, methanol hydrocarbon based solvents
Permits are potentially an issue to consider

19. Zero or Negative Cost Fuels

20. An Example of a CHP application
Waste Reprocessing plant
Washing Plastic Food Crates
Uses a submersible conveyor with direct gas fired heaters (effective heating water to 700C in a tank through which the conveyor belt with the crates are transported and dried with an air knife) – replaced with a CHP
Heating load 600kWh effective
Electrical site load 400kWe +/- 150 kWe
Note the balance of supply and demand !

24. Typical Life Cycle Costs

25. Trigeneration CHCP & CHRP Reasons for use over CHP
Improve Thermal Efficiency + 20% Reduce Emissions ~ Direct & Indirect Life Cycle Cost reductions Security of supply Refrigeration Simplified

26. Applications of Trigeneration CHCP
A simultaneous demand for heat, cooling/refrigeration and power
Food & Food Retail Industry
Manufacturing and Process Industries
Hotels
Hospitals
Leisure Centers
Office and Residential Buildings
Schools and Domestic Residences

27. Trigeneration ~ Combined Heat Cooling/Refrigeration & Power

28. Sorption Refrigeration Systems
• Absorption is the incorporation of a substance into another of a different state.
e.g. Liquids into Solids
or Gases into Liquids
Absorption is basically where a material takes in another substance.
• Adsorption is the physical adherence or bonding of ions and molecules onto the surface of another phase
( e.g. reagents adsorbed to solid catalyst surfaces) .

29. Simplified Silica Gel Schematic
• Water refrigerant
• Vacuum Vessel
• H2O evaporates
• Chilled Water formed
• Silica Saturates
• Heat Regenerates Silica
• Cycle commences
• Adjacent chamber –
typically 2 chambers
• Adjacent chamber with
external thermal storage necessary

30. Simplified Lithium Bromide - Li/Br
• Water – Refrigerant
• Evaporator
• Pumps weak Sol’n
• Rectifier concentrates the solution
• Vapour driven off
• Liquefied – condensed
• Evaporates
• Care to avoid triple point solidification
DRIVING HEAT SOURCE

31. Simplified 2 Stage Li/Br
Compared with Single Stage
• Higher Generator
temperature input req’d
• Resultant higher COP
DRIVING HEAT SOURCE

32. Pressure & Temperature Relationships Li/Br
Gauge Pressure
(kg/cm2 G)
Absolute
Pressure
Temp
(oC)
Remarks 10 11
183.2
Driving pressure for
double effect type
single effect type 8 9
174.5 5 6
158.1 1 2
119,6
0.5
1.5
110.8
1 atm.
760 mmHg
100
Atmospheric Pressure
Vacuum
650.0
95.5
High Temp. Generator
Condenser Pressure
Evaporator Pressure
525.9
90.0
167.6
62.6
92.5
50.0
61.0
41.5
31.8
30.0
29.4
28.6
9.2
10.0
6.54
5.0
5.68
3.0

33. Simplified Ammonia Absorption Refrigeration Plant (AARP)
• Temp +5oC down to -60oC
• NH3 refrigerant /H20
absorbent
• Flexible and rapid temp
adjustment/ start up
• Only one moving part
(pump)
• No refrigerant losses
• Low Maintenance
• No Triple point issues
• Long Life >30 Years
• Performance a function of
plant temperatures
• Fuels Cost Low Zero Negative
Carbon/Cost –
opportunity

34. Operation of Ammonia Absorption Refrigeration Plant (AARP)
• Evap +5 – 600C
• Gen heat +95 to 1800C
• Various heating media
- steam
- hot oil
• Condenser low temp
e.g. + 56% -500C
+43% -400C
• Various cooling soln’s
- industrial brines etc

35. Food Industry Applications for Trigeneration
• Generally food process where CHRP is needed
• Ideal consideration on new investment
• Retrofit when considering time expired
plant needing / or environmental upgrade
• It needs planning from conception

36. Trigeneration Industrial Applications
Food & Pharmaceuticals
Freeze Drying
Food Refrigeration
Cold Storage
Dairies
Ice Making Plants / Ice Storage.
Ice Cream Plants
Meat Processing
Fish Processing Industries.
Blast Freezing / Cold Stores
Solvent Recovery
Industrial Processes

37. AMMONIA ABSORPTION REFRIGERATION PLANTS (AARP)
Steam / Heat Driven
Wide refrigeration temperatures from + 5oC to –60oC.
Accepts Heat source of ≥ 85oC.
No moving parts, except a robust centrifugal pump.
High availability reliability, low maintenance.
Fully automatic. No running attention required.
Outdoor / rooftop installation possible.
Long life even beyond 40 years.
Best efficiency up to 30% of rated capacity.
Oil-free refrigerant, no fouling problems.

38. Ammonia Absorption Refrigeration Plant

39. Polygeneration Dairy Complex in Govind Dairy India with Integral Block Ice Making Plant
Fuel waste sugar cane husk,
coal, wood, other waste fuel
21 bar G
Steam driven electrical turbine
Steam exhaust powers AARP
Complete cooling services
Integral ice making plant

40. Example of Relative Payback/ Cost Conventional vis CHRP

41. Chilled Food Application at 1 Tonne/hr Dairy Produce Chilling Yogurt

42. Assumptions for Comparisons
Tri-gen plant producing at 80kWe
Process heating Hx2 = 71 kW
Regenerative Hx1 = 45 kW
Spiral cooling duty = 55 kWr
6000 hrs p.a. production plan

43. Economic Comparison of Conventional ~ Tri-generation
Conventional Plant
Tri-generation Plant
Capital cost
£ 35k
(Refrigeration plant + heating)
£110k
(Based on MGT)
Electrical requirement
52.5 kWe (Imported Main Grid)
25 kWe (to drive the fans, lights etc). (From the 80 kWe CHP plant)
Exported electricity
0 kWe
55 kWe
Gas consumption
88.75 kWf
285.7 kWf
Running cost p.a.
£ 38,513
£ 42,855
Equivalent exported energy cost p.a.
£26,400
Net running cost p.a.
£ 16,455
Relative maintenance
similar for both installations
Capital cost difference
+ £ 75,000
Net running cost difference
-£ 22,058
Pay back on the difference
3.4 Years

44. Comparison Between Conventional and Tri-generation System
Conventional System
Overall Efficiency: 51 %
Running Cost: £800 p.w.
CO2 Emissions:12.6 t/day
Tri-generation System
Overall Efficiency 73 % (COP=0.35)
Running Cost: £440 p.w
CO2 Emissions: 5.3 t/day
Note: Efficiency and environmental performance of tri-generation system will increase significantly when low temperature absorption refrigeration systems with COP (Coefficient of Performance) close to 1.0 are achieved.
Doug Marriott Associates Saving Business Energy

45. Acknowledgements
We acknowledge with thanks the Co-Funding Provided by Defra
under the Advanced Food Manufacturing Food Link Programme.
The project is directed by Prof Savvas Tassou Brunel University.
The Consortium in the AFM project in addition to the above is:
Tesco, Somerfield - Co-op, A&N Shilliday & Co Ltd, Cambridge
Refrigeration Technology, Bond Industries Ltd, Bock
Kaltenmaschinen GmbH, ACDP, Apex Air Conditioning Ltd, CSA,
Bowman Power Group Ltd, Danfoss Ltd, George Barker
& Co (Leeds Ltd) - part of the Elfi Group, Cogenco Ltd &
Doug Marriott Associates Ltd

46. Some Grants and Funding & Options
Option 1 Community & Charitable Grants <£30 K
Option 2 ECA 100% first year Energy Saving /
Low Carbon/Water Conservation
● Option 3 Shell Springboard < £40 k
● Option 4 Defra - Rural Enterprise Scheme
● Option 5 Collaborative Research TSB
● Option 6 Low Carbon Building Programme
● Option 7 Renewable Heat Incentive
Alternative
● Option 8 Waste heat generation of Electricity % recovery

47. Other References and Web Access       
Doug’s Em Tel +44(0) Mob +44(0)

48. Site Photos

49. A Packaged 500kW CHP
Doug Marriott Associates Saving Saving Business Energy

50. 18 Cylinder 1500 kWe Genset
Doug Marriott Associates Saving Business Energy

51. Retrofit CHP with existing Boilers
Doug Marriott Associates Saving Business Energy

52. Saving Your Business Energy Worldwide
Doug Marriott
BSc CEng CSci FIEE FIET FInstR MInstPet MEI FIFST FRSA
Chartered Engineer  - Chartered Scientist
Director Doug Marriott Associates Ltd
Tel +44(0) Mob +44(0)

53. End of slides