Combined Heat and Power
Generation in Jamaica’s
Sugar Cane Industry
Niconor Reece
Sugar Industry Research Institute
Manchester, Jamaica
Introduction
• Energy potential of Bagasse being
underutilized in Jamaica.
• Potential for Factories to expand Power
production.
• At harvest about 30% of total biomass is
lost in the field.
Introduction
• Biomass provides significant environmental
benefits.
– CO2 emission reduction
– Carbon Credits
• Biomass provides economic benefits.
– Reduce oil imports
– Foreign Exchange savings
Introduction
• Industry presently in a state of
uncertainty
• Industry up for divestment
• Divestment should bring needed
investment to the industry
The Jamaican Power Sector
• Government control since 1974 (JPSco)
• 80% Equity sold to Mirant of Atlanta
• Licensing Agreement makes JPSco the sole
buyer of bulk electricity and power from
independent power providers (IPP) in Jamaica.
• IPP provide total of 134MW to the national
supply
The Jamaican Power Sector
• Jamaica’s demand for power is growing
at a rate of 4.5% annually.
• In 2004 3,717million kwh of electricity
• Less than 9% of the power comes from
renewable resources.
The Jamaican Power Sector
• Government policy towards renewable
energy.
• 114 MW from renewable sources by 2012
• Currently 42 MW from renewable sources
• Total capacity of 1070 MW by 2012
• Tax rebates for special technologies
• 15% premium above JPSco’s avoided cost
The Sugar Industry in Jamaica
• One of the most important crop in Jamaica
• In 2004 total production was approximately 2
million tonnes of cane.
• Projections of over 3 million tonnes from 46,000
hectares of land still available for cane
production.
• Crushing season last for about six months
running for December to June.
The Sugar Industry in Jamaica
• Sugar mills in Jamaica are partially self
sufficient fuel wise.
• Two of the seven mills use bagasse as their
sole source of fuel during the crushing season.
• 5 mills depend heavily on Bunker C
• In 2004 the industry consumed 6.2 million litres
of oil at a cost of approximately 2.4 million US$
The Sugar Industry in Jamaica
Summary of crushing rate, steam and power generating capacities, and
oil use of sugar mills currently operating in Jamaica
Factory
Worthy
Park
St.
Thomas
Monymusk
Trelawny
Sugar
Frome
B/Lodge
Appleton
Total
Crushing Rate
TCH
No. Boilers
Pressure
PSI
.
Steam Output
Lbs/Hr
Power
Generation
Turbine (MW)
2004 Oil
Usage
L/oil
75
3
200
105,000
2.05
0
62
180
4
8
180
200
130,000
320,000
2.28
8
0
1,657,184
160
300
170
150
1097
3
10
7
3
150
200
200
220
126,000
420,000
350,000
357,000
2.85
8.5
5.2
3.25
32.13
1,292,307
1,998,181
758,808
441,867
6,148,347
The Sugar Industry in Jamaica
• Typical factory CHP cogenerates 20
kwh/tonne cane and 400-500kg
steam/tonne cane.
• The Industry is heavily dependent on oil
due to poor state of the boilers and
factory equipment.
The Sugar Industry in Jamaica
• Possible reduction in steam usage by:
– Retrofitting factories to economize on steam use.
– Use plate heaters, falling film evaporators, and
continuous vacuum pans.
– The two privately owned factories have made moves
to improve steam usage by installing continuous
vacuum pans. One factory also put in a 250,000 lb
boiler to replace the smaller older boilers.
The Sugar Industry in Jamaica
• Turbines
predominantly in
use are the noncondensing back
pressure type.
Incentives on CHP inJamaica
• 1989 Larson modelled the use of
biomass integrated gasification combine
cycle (BIGCC) technology and high
pressure condensing extraction steam
turbine (CEST) after Monymusk sugar
factory.
Incentives on CHP inJamaica
CEST- steam is
exhausted directly to
condensers, that
maintain vacuum
conditions at the exhaust
end of the turbine.
Steam at intermediate
pressure is extracted for
use in the milling
process.
Incentives on CHP inJamaica
• BIGCC use the combined cycle format
with a gas turbine driven by syngas from
the gasifier. The exhaust gas are heat
exchanged with water/steam to generate
super heated steam.
Typical BIGCC
Incentives on CHP inJamaica
• Using BIGCC typically 60-70% of the
power comes from the gas turbine.
• Steam production limited to 300kg/tc
• BIGCC produce substantially more
energy than CEST
Incentives on CHP inJamaica
Potential Cogeneration Using Sugar Cane Residue and bagasse
500
450
kwh Generated Per Tonne Cane
400
350
300
250
200
150
100
50
0
Typical Existing
CEST in Season
CEST Year Round
BIGCC Year Round
Incentives on CHP inJamaica
• Model results indicate:
– Typical system 20kwh/tc
– CEST 249kwh/tc
– BIGCC 460kwh/tc
– Results extrapolated for 2 million tonnes of cane:
• 920 million kwh BIGCC
• 480 million kwh CEST
Power generation initiatives
• Study –
–
1991 and 2000 Frome
1995 Monymusk
1997/98 St Thomas
• SEDEC/ Frome (SCJ) 2000
– Co fired bagasse/coal CEST system
– 1200 psi high pressure boilers
– 70 mw out put
Power generation initiatives
• The technology adopted was high pressure
condensing extraction steam turbine (CEST)
• The studies looked at the use of auxiliary fuel in
the off season.
• This varied from the use of:
– cane field residue
– coal and heavy oil
Power generation initiatives
• Model of CHP generation for the BIGCC and CEST at
Monymusk
– Crushing rate 175 tc/h
– 27 MW CEST
– 53 MW BIGCC
• Rate of return depended strongly on price paid to utility
company
– avoided cost of 5.0-5.8 cents US/ kwh (1989)
– rate of return 18-23% for BIGCC
– compared to 13-16% for CEST
Power generation initiatives
1989 results of financial calculations, based on a 206-day milling
season (Larson 1989)
Electricity Sale Price
Co-generation Technology
Exported electricity
Million kwh/year
Internal Rate of Return (%/year)
Base case a
Alternative BIGCC fuel processing
None
Drying
Baling/drying
Pelletizing
Alternative off season fuel
Oil/biomass
5.0 US
cents
CEST
5.0 US cents 5.8 US
cents
BIGCC
CEST
5.8 US
cents
BIGCC
178
360
178
360
13
18
16
23
24
22
21
11
10
11
29
27
26
16
12
13
Power generation initiatives
• In 2000 SEDEC/SCJ co-gen at Frome
• CEST technology
– 1200 PSI boilers
– co-fired by bagasse and coal
– 70MW output
Power generation initiatives
• delivery of 440 million kwh/year
• cane supply to Frome of 750,000 tonnes
• bagasse rate of 85 tonnes/hr.
• mill steam consumption 400kg/tc
• electricity requirement of 30kwh/tc
• Cropping season of 2885 hour.
Power generation initiatives
• economic evaluation indicated that
– at maximum capacity of 440 GWh/year, the
price of electricity would be at 6.2 cents
US/kwh
– and at a minimum 340 GWh/year 7.1 cents
US.
– This would realize a yearly profit of 20%.
Present Problems and Future
Potentials
• In 2000 the United Nations Development
Programme (UNDP) promote the
adoption of renewable energy by
removing barriers and reducing
incremental costs.
Present Problems and Future
Potentials
An analysis of barriers to the development of CHP in Jamaica showed the
following:
•
Information awareness and other barriers:
•
There was a lack of awareness with key decision makers at the highest
political level.
•
Limited knowledge on cost effective co-generation market potential for
the sugar sector.
•
Investment on bagasse co-generation must be done jointly with
upgrading efficiency of the sugar process.
•
Social impacts of potential change in harvesting practices.
•
Concerns about fall off in sugarcane production.
Present Problems and Future
Potentials
Technical Barriers
• Limited technical capacity to design, install,
operate, manage and maintain co-generation
technologies.
• The infrastructure for supply of cane residue on
a cost effective basis
• No infrastructure for the storage of bagasse
and cane residue
Present Problems and Future
Potentials
Policy Barriers
•
Despite having an energy policy favourable for the development of renewable
energy sources; no clear strategy, including fully developed policy instrument does
not exist for the implementation of the renewable energy policy.
•
Unclear political responsibility for an electricity generation project, in the
agricultural sector.
Financial Barriers
•
High capital cost of co-generation equipment and projects.
•
Investment capital of the sugar mills is often completely committed for sugar
related investment.
•
Government budgets are limited and demands for financing various national
priority areas are extensive, leaving no space for financial incentives to promote
co-generation projects.
Present Problems and Future
Potentials
Factors that make CHP feasible for Jamaica include:
The centralization of the industry
– closing of two smaller factories
– increasing the cane supply
– added throughput for the remaining factories
– more bagasse production
Jamaica, being a signatory to the Kyoto protocol
– will have to give serious consideration to green cane
harvesting.
– This will provide significant field residue to be used as
auxiliary fuel for bagasse in a co-generation system provided
economic collection and storage systems are put in place.
Present Problems and Future
Potentials
• Prospective investors will have to invest heavily in
upgrading factory and CHP systems
• It would be more beneficial if this capital was used to
establish modern CHP systems that would supply the
sugar production process with steam and power and sell
the excess power to the national grid.
• There is ongoing research in the development of varieties
to increase cane fiber yields through genetic improvement.
This could increase fiber in bagasse to co-generation
plants and consequently increase power out-put, possibly
eliminating the need for auxiliary fuel.
Conclusion
• There have been numerous initiatives in Jamaica for the
sugar mills to supply power to the national grid both during
and outside their sugar harvesting season.
• This way of power generation is likely to trigger mainly
positive environmental impacts and a higher than usual
national value added in the cost of electricity generation.
• Inability to overcome some barriers hampering
implementation, 15 years have elapsed without any
meaningful move to produce excess power via
cogeneration.
• It is hoped that the divestment of the Industry will help to
bring about some of these changes.