reduce energy costs and 2 emissions. · 2014-04-01 · steam boiler or 3-pass heat exchanger (with...
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Reduce energy costs and CO2 emissions.Energy-efficient solutions for chocolate and cocoa production.
It all starts with an in-depth process analysis. Buhler energy audit reveals opportunities.
The energy audit can be viewed as a starting point for
improving efficiency. It helps to provide a picture of the
current situation of all the product and energy streams
of a production plant. For this, Buhler uses a specific
approach, known as the ‘Pinch’ method.
At the heart of the Pinch method – which is recom-
mended by the Swiss Federal Office for Energy – is the
process itself. But another important point is that this
approach also allows economic factors to be considered,
e.g. desired pay back time. The Pinch method therefore
not only helps to optimize a production plant in terms of
2 BUhlER EnErgy-EffIcIEnt solutIons
energy, but also economically, i.e. the plant is energeti-
cally optimized to the economic criteria of the processor.
The most important aspect of the entire energy analysis
is detailed knowledge of the process, which means that
suggested measures for improving energy efficiency will
be verified by Buhler process experts regarding their
technological feasibility.
The result of the energy audit offers a clear picture of all
energy and product streams that are relevant for the pro-
duction of your products. The Sankey diagram shows the
production process in terms of energy flows, and is thus
Buhler offers customers a seamless range of products and services, from raw cocoa beans to the
finished moulded chocolate articles. The company’s philosophy is to support customers at every
relevant step. Buhler regards climate change as a call to create new services and solutions. That
includes analyzing the current situation, defining relevant and appropriate measures for improving
efficiency, implementing the proposed measures and, finally, checking whether the implemented
measures achieve the proposed targets.
Analysis Definition Implementation Control
a perfect starting point for defining measures for improv-
ing energy efficiency.
Buhler process experts will work out a catalog of
measures which contains proposals as to how the en-
ergy efficiency of your plant can be improved. For these
measures, the economic criteria that you specify, such
as investment or desired pay back time, will be consid-
ered. Furthermore, since Buhler process experts are
deeply involved in the energy audit process, Buhler can
guarantee that all proposed measures can also finally
be implemented without affecting the product quality or
production reliability.
Primary energy DistributionTransformation Production line A + B
5210
1160
10 Air cooler
Losses
1380
4210
Water cooler
Feed water preheatExhaust air
Feed water 89050
890 Steam boiler2310Natural gas
Legend
Electricity
Natural gas
Steam 10 bar
Recirculated water cooling at 45 °C
Recirculated water glycole cooling below 20 °C
Losses
22150 20380
Steam distribution
2700
16520
260
1300
3860
80
50
80
390
310660
410
1760
1150
Blocking off & cooling
Tempering
Grinding & storage
Winnowingshell handling, storage,
aspiration, nibs handling and scaling
Exhaust air 10050
Compressed air
Storage & conveying
Intake, cleaning, aspiration
Debacterizing
RoastingSteam condensate
1040
Losses
All streams in MWh/a
Optimized chocolate mass production line with a production capacity of 1,000 kg/h.
Pinch evaluation and consideration
of economic criteria.
BUhlER EnErgy-EffIcIEnt solutIons 3
Sankey diagram: energy and product streams at a glance.
960
940
920
900
880
860
840
820
800
0 20 40 60
Yearly cost [kF/y]
deltaT min [°C]
Economic criteria:Yearly cost 808. [kF/y]
250
200
150
100
50
0
0 1000 2000 3000 4000
Temperature [°C]
Heat rate [kW]
1,660 kW primary energy demand
1,750 kW, 1,040 kW from exhaust air
Heat recovery approx. 1.1 MW
new approaches to cocoa processing.Energy-efficient debacterizing and roasting systems.
Process configuration for debacterizing
cocoa beans.
A newly developed STP™ (short-time-peak-pressure)
process allows shorter retention time in the reactor and
significantly reduces the specific steam consumption.
Furthermore, a process configuration in which the de-
bacterization step is situated after the roasting process
enables additional savings in steam consumption. Overall
savings of up to 50% for the debacterizing process step
can be achieved.
Heat recovery systems designed for high efficiency.
Specialized heat recovery systems for the Buhler Barth
TORNADO drum roaster and RoaStar™ fresh air roaster
provide savings of between 15–30% of the primary en-
ergy demand.
The heat recovery system for the Buhler Barth TORNADO
drum roaster consists of two main components. Firstly
the heat exchanger itself, which is specially designed
to suit the air volume and temperature used. Secondly,
a specialized gas burner application which enables the
utilization of preheated combustion air. The heat recovery
systems for the Buhler RoaStar™ fresh air roaster are
designed on the principal of a double water circuit. This
enables the utilization of at least an additonal 10°C of
heat recovery temperature compared with a single water
circuit heat recovery system. heat recovery systems for
Buhler Barth roasters are designed to realize a payback
period of approx. 2–3 years (at 7,000 h/a production time
and 3.5 Euro-Cent/kWh).
Savings energy and CO2 emissions.
5.5
6.0
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
psteam 8 bar psteam 6 bar
reduction of process time approx. 10sec. (about 25%)
0 5 10 15 20 25 30 35 40 45 50
Overpressure [bar]
STPTM
Cycletime [s]
4 BUhlER EnErgy-EffIcIEnt solutIons
Buhler BarthDebacTM System.
Shorter retention time due to STP™ (short-time-peak-pressure) process.
Debacterizing and roasting processes are decisive
factors when it comes to saving energy and costs.
However, common systems only make use of a
fraction of the energy they consume. Buhler Barth
debacterizing and roasting systems are more clev-
erly designed. They not only convince with their
quality, throughput and total productivity, but also
by using energy efficiently.
RoaStar™type
Yearly energy savings [€]*
Reduction of CO2 footprint (t/a)**
4t/h 150,000 850
3t/h 95,000 540
2t/h 68,000 390
1t/h 41,000 230
0.5t/h 23,000 130
Efficiency degree of 90% considered* cost of energy 0.035 €/kWh @7000 h/a, ** natural gas 200 g/kWh
BUhlER EnErgy-EffIcIEnt solutIons 5
Cooler 1
Fresh air
Heater 1
Heater 2
Cooler 2
Exhaust Air
100°
90°
80°
70°
60°
50°
40°
30°
20°
10°
90°
72.5°
66.5°
Air delta 17.5°
71°
65°
47.5°
delta 4.5°
Air delta 17.5°
30° 30°
delta 4.5°
Air delta 17.5°
47.5°53.5°
49°
55°
90°
Air delta 17.5°
72.5°
Exhaust air 90° –> 55° Fresh air 30° –> 65°
Water
Water
Temperature profile – heat recovery system for RoaStar™ fresh air roaster.
Buhler Barth RoaStarTM continuous fresh air roaster. Buhler Barth TORNADO drum roaster.
heat recovery system for Buhler Barth RoaStarTM.
heat recovery system for Buhler Barth TORNADO drum roaster.
Specialized gas burner for Buhler Barth TORNADO drum roaster.
6 BUhlER EnErgy-EffIcIEnt solutIons
Cocoa shell combustion system.
Cocoa shells are the future source of energy in cocoa
processing. The advantages of generating energy from
cocoa shells are manifold. Firstly, enormous savings
in the cost of energy can be achieved by utilizing the
cocoa shells which are produced as waste during cocoa
processing. Secondly, by utilizing cocoa shells as a
source of energy, modern cocoa processors are able to
reduce their carbon footprint tremendously. Especially in
combination with the RoaStar™ and Debac™, which are
steam based roasting and debacterizing systems, a ther-
mally self-sufficient processing system can be realized.
That means all the thermal energy required for roasting
and debacterizing cocoa beans is generated from the
cocoa shells. Furthermore, modern cocoa processors
are independent of fluctuations on the energy market as
no fossil fuel is required and calculation of future produc-
tion costs is more accurate. As the EU sponsors projects
designed to save fossil fuels, producers within the EU
can essentially benefit from partial government and EU
funding of the capital that they spend on cocoa shell
combustion systems.
Key criteria in cocoa shell combustion.
From a commercial and ecological viewpoint, two main
criteria must be fulfilled by a shell combustion system.
Trouble-free operation must be ensured with a main-
tenance requirement that is acceptable to the cocoa
processor. From an ecological viewpoint, the emissions
caused by combustion must be within the acceptable
A natural source of energy.Cocoa shell combustion.
Cocoa shells are an inevitable by-product when it comes to cocoa production. Buhler has developed
a tailor-made combustion system to generate energy from cocoa shells. What was formerly a waste
product is thus turned into an energy source that even allows the design of thermally self-sufficient
roasting and debacterizing processes.
Savings energy and CO2 emissions.
RoaStar™type
Yearly energy savings [€]*
Reduction of CO2 footprint (t/a)**
4t/h 490,000 2,800
3t/h 368,000 2,100
2t/h 245,000 1,400
1t/h 123,000 700
0.5t/h 61,000 350
Efficiency degree of 90% considered* cost of energy 0.035 €/kWh @7000 h/a, ** natural gas 200 g/kWh
BUhlER EnErgy-EffIcIEnt solutIons 7
steam boiler or3-pass heat exchanger(with automatic cleaning feature)
secondary air-injection socket
low nox-firebox
recirculation over grate (optional)
moving grate
fuel supply via hydraulic direct-push rod or screw conveyer
primary air supply
automatic firebox de-ashing
Cocoa shell combustion system.
heavy duty moving grate.Combustion chamber for cocoa shells.
limits applicable to conventional biomass combustion
systems. Within the EU, the German Clean Air Act can be
used as a general benchmark.
In biomass combustion, particular attention needs to be
paid to the residual ash content and ash melting point
of the respective biomass. A combustion chamber grate
which is purpose-designed for the cocoa shell applica-
tion ensures complete ash incineration, preventing
caking on the combustion chamber grate, and guaran-
tees a constant combustion process temperature. At
the same time, it enables acceptable CO, NOx, and dust
emission values to be achieved, which are within the lim-
its of the Clean Air Act. In the presence of more rigorous
regional regulations, the exhaust air can be additionally
treated using common dust collection filters and cleaning
components. An automatic cleaning feature in the steam
boiler helps to avoid power loss as a result of steam pipe
contamination.
Advantages at a glance.
– less down time for maintenance
– Suits high ash content of cocoa shells (10%)
– Suitable for melting point of ash
– Optimizing of combustion behavior –
enough surface on grate – long afterburning effect
– No deposit on combustion chamber grate
– No performance loss due to deposits in steam boiler
Value added with autarchic roasting system.
– Used in combination with the optimized variants of
Debac™ and RoaStar™
– Appreciable cutting of energy costs
– Appreciable reduction of carbon footprint
– Process energy generated from shells
– Optimal utilization of shells – no extra disposal
– Emissions within acceptable limits of EU regulations
– Independent of fluctuations on the energy market
– Partial government and EU funding
Main features.
– Moving grate – special cocoa shell design
– low-NOx-Firebox
– Screw or water cooled direct push rod
– De-ashing rod below grate
– Water cooled grates
– large volume, heavy-duty construction
– Fully automatic de-ashing
Possible applications.
– Stand alone for RoaStar™ and Debac™
– Integrated into customer’s steam system:
– biomass combustion provides basic load
– peak consumption covered by gas or oil-fired
steam boiler
– e.g. steam for alkalization
– Redundancy configuration with gas or oil burner fitted
at combustion chamber for emergency operation
8 BUhlER EnErgy-EffIcIEnt solutIons
Buhler Barth RoaStar™ in operation with steam produced using cocoa shells.
BUhlER EnErgy-EffIcIEnt solutIons 9
Automation.
An energy-efficient automation process enables potential
reduction of energy costs through efficient planning and
monitoring of consumption. Accurate recording over a
long period of time allows the energy consumption to be
analyzed. Additional features, such as optimization of
energy consumption through automatic starting and
stopping of process lines or definition of user-specific
energy limits in combination with cost controlling, can
also be implemented.
– WinCoS.r2 measures the current energy consumption
and monitors this against a user-defined limit value.
Excessive energy usage is prevented.
– Each process line can be individually configured and
controlled.
– With real-time monitoring, the power factor compensa-
tion can be optimized.
– Actions performed by WinEnergy are stored in a
dedicated data logger to enable traceability of events.
– Measurement points can easily be added.
– long-term comparisons are possible at any time.
Active energy management.Efficient planning and real-time monitoring.
An efficient automation process is the prerequisite for saving energy and costs. The control system
WinCoS.r2 monitors energy streams and consumption in real-time. Energy costs can be properly
allocated to the products. The result: active energy management.
Modern control station of a chocolate processing line.
Real-time monitoring of energy consumption.
High efficiency motors for chocolate grinders.
By using high efficiency motors of class IE2 or IE3, an
efficiency increase of between 2–8%, even at partial
load of 60%, can be realized. The substitution of motors
requires very little adjustment. The exchange of motors
can easily be realized. however, further potential lies also
in the respective drive concept of the chocolate grinder.
There are various factors that influence the efficiency of
the grinder (see box). Buhler engineers are able to verify
the appropriate solution that fits perfectly to your ap-
plication. The result is a highly efficient solution that is
customized to meet your specific needs.
Advantages at a glance:
– Reduction of power consumption
– Reduction of electrical connected load
– Reduction of energy costs and CO2
Buhler technology for continuous improvement.Chocolate mass production and moulding.
10 BUhlER EnErgy-EffIcIEnt solutIons
Buhler is continuously on the look out for new technologies to improve chocolate mass production and
moulding. High efficiency motors for chocolate grinders and the new SeedMaster™ technology open up
further opportunities to save energy. Buhler chocolate grinders stand both for high product quality and
productivity. With the SeedMaster™, Buhler developed a new chocolate tempering process that enables
customers to reduce energy consumption by up to 75%.
Chocolate grinder Finer-V™ with high efficiency motors.
100
95
90
85
80
70
75
0,1 1 10 1000100
Nominal efficiency (%)
Motor output [kW]
10%
2%
0.75 kW to 375 kW
IEC 60034-30 (Ed. 1.0) 2008
IE 3IE 2IE 1
Comparison IE1, IE2 and IE3 efficiency class motors.
Action Savings
System installation or renewal
Efficient motors 2 – 8%
Optimum dimensioning 1– 3%
Efficient motor repair 0.5 – 2%
Drive system with frequency converter 2 –10%
Belt drive, gear 2 –15%
Quality power supply 0.5 – 3%
System operation and maintenance
Lubrication, settings 1 –5%
Energy saving potentials for grinders.
Secondly, – depending on the application e.g. for a filled
product – SeedMaster™ tempered chocolate from the
overflow can be fed directly to the depositor again, and
thus does not need to be de-crystallized and re-temp-
ered again (see flow sheet comparison). This results in
additional savings so that, when used for a filled product,
up to 75% of energy can be saved compared with a con-
ventional tempering system.
Advantages at a glance:
– Up to 40% lower electrical connected load
– Up to 75% reduction in energy costs
– Significantly increased product quality (e.g. fat bloom)
BUhlER EnErgy-EffIcIEnt solutIons 11
SeedMaster™ – new chocolate tempering process.
Through a seeding pre-crystallization, a large amount of
very small cocoa butter crystal seeds are mixed homog-
enously into a chocolate mass. This allows for prompt
crystal solidification and a build up of a compact crystal
network of the cocoa butter. The result is a product with
improved fat bloom stability, higher strength and signifi-
cantly better gloss.
however, the SeedMaster™ technology also offers high
potential for energy savings. Savings of between 40–75%
of energy can be achieved for two main reasons. Firstly,
the SeedMaster™ technology requires approximately
40% less primary energy in the tempering process itself.
Depositor
Depositor
Hopper
De-crystallizer
SeedMaster
Shell forming
Shell formingConventional
temper
machine
4000 kg/h
2880 kg/h
2880 kg/h
1120 kg/h (start 4000 kg)
TM
Comparison: SeedMaster™ vs. conventional tempering system. (Capacity of moulding line: 4,000 kg/h – filled product)
Moulding line with SeedMaster™tempering system
Conventional tempering system
SeedMaster™ tempering system in combination with Buhler Bindler MultiStar™ moulding line.
Bühler Ag
cH-9240 uzwil, switzerland
t + 41 71 955 11 11
f + 41 71 955 35 82
www.buhlergroup.com