Wasted energy in coating installations. Use CPC to eliminate this...

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Energy Revision 1
Emissions and Energy Losses in Coating
and Heating Processes
F. Rombach B.Sc. (M.E.)
Summary
The CPC process simulation programme identifies high energy losses, excessive
CO2 emissions, Wasted Energy and poor production management in the coating
industry.
The process simulation programme is unique in that it uses as a reference the
actual thermal curing or drying process design parameters and operating
conditions of the plant.
The programme has been field tested and run over a number of years: it
provides accurate environmental, energy and production solutions to optimize
energy consumption and to reduce the environmental impact of thermal and
coating processes.
The programme has been developed to suit EU directives and EPA regulations:
it can be used for Government Inspections, training in process and coating
technology, process design and production control in coating plants, marketing
of new paints and powders and other applications.
Wasted Energy has been highlighted in this report.

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Energy Revision 1
Contents
1 Introduction 2
1.1 General Outline 2
1.2 Some Examples of Energy Wasting Installations 3
1.3 Simulation and Calculation Screens 4
1.4 Estimates of Wasted Energy and CO2 Emissions 5
2 Conclusion and Opinion 6
***
1 Introduction
1.1 General Outline
Almost all thermal processes in the coating industry are based on out-of date
assumptions and experience.
“Silhouette loss may be defined as the heat loss from work access openings
in a curing or drying oven”
The silhouette loss is caused by the stack effect: high temperature always rises and
cold air always comes down. The work access opening (or silhouette opening) of an
oven shows the same conditions corresponding to the stack effect.
This means that hot (oven) air escapes from the top of the opening while cold air
(infiltration air) enters the oven through the lower part of the opening.
From this follows that the higher the opening, the greater the silhouette loss.
Also, wider openings give higher losses than narrow openings.
The infiltration air must be heated and the escaping air has been previously heated but
has not performed any work, i.e. the heating of the work pieces or drying of paint.
So in effect there is a situation where air has been heated for no purpose, except
to create CO2 Emissions. At the same time energy (natural gas or electricity) has
been wasted for this purpose.
These CO2 Emissions, Energy Losses and Wasted Energy are addressed in the CPC
process simulation programme.

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Energy Revision 1
1.2 Energy Wasting Plants and Excessive CO 2 Emissions
In the pictures the silhouette openings are clearly visible.
Poor production management is also displayed: the above pictures are freely available on the
Internet as marketing pictures for oven and plant manufacturers.
These present day ovens do not show any effort by manufacturers to reduce the silhouette losses
and the energy waste; in fact, some of the pictures show a maximum of inefficient work loading and
poor oven air seal design, resulting in high CO2 emissions and wasted energy.
The oven on the left is provided with automatic doors to reduce
the opening to the width of work passing or to completely
close the oven if no work is passing.
The design was made in 2000, with the approval of the client, as
in this case it involved increased plant costs.
Today this type of plant could be called a ‘Green Plant’.
A typical example for application of an
automatic control of silhouette openings.
Shown here are the entry and exit openings
of an oven on the same coating line.
Powder is being replaced in a number of coating processes by
low temperature curing paints.
The draw back is that this results in most cases
in increased VOC emissions.

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Energy Revision 1
Powder and Paint Processes
Also availabe in United States Units

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Energy Revision 1
1.4 Conservative Estimates of CO 2 Emissions and Wasted Energy
Baseline for CO2 Emissions and Wasted Energy: data from plants in Holland
Installations Total : 870 Continuous Ovens : 350
For the calculations coating plants are divided into 4 categories, each with its own design and production requirements.
Special plants, such as car repair plants, truck body builders, etc. are not included because of absence of information.
At this moment the actual number of plants appears to be 40-50% above the numbers shown below.
Wasted or lost time for paint spraybooths, fresh air units and ovens is now included in coating processes.
Wasted Energy General : 150-400 kW Average for Standard Coating Processes
Countries Coating CO2 Emissions Wasted Energy
EU Plants Tons per year GW Mln Euro
per year per year
Austria 420 149 000 723 31
Belgium 563 200 000 970 41
Denm ark 271 96 000 487 96
England 3188 1 134 000 5 494 234
Finland 276 98 000 476 20
France 3 255 1 158 000 5 608 239
Germ any 4186 1 489 000 7 213 307
Greece 594 211 000 1 023 44
Ireland 215 76 000 370 16
Italy 3055 1 087 000 5 265 224
Netherlands 870 309 000 1 499 64
Poland 1975 703 000 3 404 145
Portugal 542 193 000 935 40
Spain 2390 850 000 4 118 175
Sweden 486 173 000 838 36
Other 12 Countries 614 218 000 1 058 45
Totals EU only 9 065 000 43 923 € 1 872
EU Annual W asted Energy based on an average Natural Gas Cost of € 0,39 per m³
United States 16 069 5 616 000 27 689 € 1 179
Estimates are based on EU data and USA greenhouse gas emissions
USA Annual W asted Energy based on an average Natural Gas Cost of $ 9.20 per 1000 ft3

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Energy Revision 1
2 Conclusion and Opinion
Remarks on Energy Revision 1
- The total number of plants per country has now been included
- Official reference data in Dutch CBS report for the year 2012:
- Total number of windmills in Holland 1 882
- Actual electricity production as per CBS report 4 298 GWh
CO2 Emissions
A considerable quantity of CO2 is emitted in coating processes, not only from curing or drying
ovens, but also as a result of heating fresh air required for operation of spraybooths in wet
paint coating installations.
Fresh air heating is not required for powder coating spraybooths.
This applies to both solvent based and water borne painting systems.
In all paint application systems the spraybooth losses are considerably higher than the oven
losses, for several reasons.
There are a number of simple options available to reduce the CO2 emissions and losses: these
can be readily implemented and manufactured, as ample technology is available for this
purpose.
This means that the time lost for designing and installing additional equipment is very short
and costs will be low.
Wasted Energy
How does one arrive at the Wasted Energy figures?
By using a combination of standard process and design calculations for coatings installations
-and- by observation of the production processes in coatings plants.
The CPC Process Simulation programme has been developed using these calculations and
the result of these observations. Over a period of more than 12 years the programme has
been verified in the operation of a number of plants.
This is not magic, any competent Engineer can verify my calculations, if need be.
My Opinion
Coating finishing systems and their emissions will always be with us, so pretending
there are no difficiulties or that the cost of modifications is prohibitive, does not solve
any of the problems.
The CO2 emissions from coatings plants generally exceed the EPA regulations in a number of
countries, yet virtually no action has been taken.
But the biggest problem, i.e. Wasted Energy, is still not addressed: you can build as
many windmill farms as you like, but you will loose 30-50 percent of the produced
renewable energy if you ignore Wasted Energy.
The opportunity for a fresh approach to solving the CO2 Emissions and Wasted Energy is
here, but the question is: what does it take to commit resources to these problems and to
evaluate and design efficient and cost effective alternatives to solve these problems in the
short and long term?
From my engineering point of view there are just no more excuses for delay...
F. Rombach
Date 05 November 2012