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| Holistic approach to EE at Pan Century Edible Oils |
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Benefits
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35,000 GJ in annual energy saving from steam system optimisation |
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Reduced steam consumption by 10 percent |
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Reduced power demand at four cooling towers by 8 percent |
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Average payback period of 1 year to 2 years |
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Monitoring and targeting for continuous improvements |
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Total energy cost saving of RM1 million from four EE projects |
Summary
Pan-Century Edible Oils (PCEO) Sdn Bhd, a manufacturer of
oil refinery products and specialty products, is one of the 48
factories audited by the MIEEIP team under the Energy Audit
Programme. The factory’s monthly energy bill amounts to RM2
million. The aim of the audit is two folded, namely, to identify
energy cost saving potentials and transfer the auditing skill to
the staff of PCEO. Jointly, the MIEEIP audit and the PCEO
energy management teams identified several potential energy
cost saving measures. A combination of measures
recommended by the MIEEIP and PCEO’s energy teams on
steam management, cooling tower modification, energy-use
monitoring and targeting, and the replacement of standard
motors to high efficiency motors are discussed here as local
case studies for industrial energy efficiency.
Project Overview
PCEO commenced its operations in Malaysia 25 years ago,
and to date has 13 plants at a single location in Pasir Gudang,
Johor. Its total manufacturing capacity of oil refinery products
and specialty products is about one million tonnes. The factory
recorded an annual turnover of RM 750 million in 2002. This
internationally recognised company, which is a member of
the Aditya Birla Group, has a workforce of 285 people.
The company had already established a Focused Improvement
Project Team (FIPT) prior to the collaboration with MIEEIP. FIPT,
which was tasked with overall improvement strategies,
responded positively to several MIEEIP recommendations on
steam management and implemented them systematically. Its
initiatives on other energy efficiency improvement areas are
ongoing and closely monitored for comparisons against
established norms under the in-house Purta or benchmarking
system.
Project Overview
Project One : Steam optimisation
More than 550 tonnes of steam is generated daily for physical
refining, making soap noodles, tank farm heating and
fractionation. During the audit, the team identified significant
steam leakages and analysed the respective losses. To minimise
these losses and to implement other energy cost saving measures, the management embarked on a RM 1.0 million
venture. To date, the steam optimisation programme has alone
resulted in an annual energy cost saving of RM680,481. Other
measures that were already initiated by PCEO are modifications
to the factory’s cooling towers; replacement of standard motors
with high efficiency motors; steam conservation schemes, heat
recovery schemes and monitoring & targeting, which produced
a total energy cost savings of RM320,000. PTM has agreed to
do the study of compressed air system and chilled water system.
Background
PCEO operates four units of boilers to supply steam to the
refining and soap noodle plants. Steam is generated at a cost of
RM50 per metric tonne, whereby 90 percent of the cost
component is for fuel purchase while maintenance, chemical
treatment and water consumption make up the balance 10
percent. About 55kl (kilo litre) per day of Medium Fuel Oil
(MFO) is consumed. Realising the immense benefits of the
energy saving measures and in view of the increasing fuel and
water costs, PCEO embarked on a holistic approach to optimise
the existing steam supply and demand structure. Steam saving
target was set at 10 percent and to facilitate this, the FIPT
immediately got to work to further confirm and implement the
energy saving measures.
Project Implementation
The energy saving measures identified by the team for the steam
supply and demand system were divided into no, low, and high
cost categories. PCEO used both its in-house financial resources
and expertise to implement the identified Energy Cost Reduction
Measures (ECRMs) in stages since May 2002. The high
commitment and seriousness showed by the factory’s top
management ensured the full completion of the projects within
an eight-month period. Through monitoring and verification,
the savings were quantified and reviewed on a monthly basis
for the following measures:
| I. Use of low pressure steam (3.5 barg) for tank farm
heating and tracing lines in place of medium pressure
steam (14.5 barg) |
| Audit findings |
The maximum temperature required for
tank farm heating and tracing lines is between 70° and
80° C , which can be attained with low-pressure steam.
Currently the heating is carried out using medium
pressure steam. |
| Measure recommended |
To convert the current heating
system heating to low pressure |
| Action Taken |
The present medium pressure header was provided with pressure regulating valves to supply low pressure steam for tank farm heating |
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| ll. Installation of pressure regulating valves for steam to
distillation vacuum plant |
| Audit findings: |
The design vacuum pressure for the
distillation plant is 10 barg at a steam header pressure of
13.5 barg. This combination of settings resulted in higher
steam consumption amounting to 24 percent. |
| Measure recommended: |
To supply the steam at an
optimum pressure of 10 barg. |
| Action taken: |
Pressure regulating valves were installed
in the acuum circuits to maintain the steam supply
pressure at 10 barg. |
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| III.Insulation improvement |
| Audit findings |
An insulation survey for the entire plant
was carried out to identify areas of insulation losses. It
was found that many steam lines were not properly
insulated. |
| Measure recommended: |
To carry out an audit of the
steam distribution system to determine the various sizes
of insulation to inimise the losses and rectify the steam
leakages. |
| Action taken: |
All condensate return lines, valves, and
fittings were provided with correctly sized insulation to
prevent heat losses. The temperature difference between
the pipe surface and the ambient, maintained at around
10°C after the rectification, not only saves energy but
also creates a thermal-comfort working environment. |
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| IV. Steam trap maintenance |
| Audit findings: |
Steam traps were found either under
sized or leaking due to the lack of maintenance. This in
turn contributes to the ineffectiveness of the entire steam
distribution system. |
| Measure recommended: |
Conduct a survey on the
existing steam traps and replace the under sized ones,
and establish a steam trap periodic maintenance system.
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| Action taken: |
Suitable sized traps were provided and a
strict steam trap checking procedure was implemented
to detect faulty traps before installation |
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| V.Condensate recovery |
| Audit findings: |
The steam condensates at the various
points of use were not recovered, because of possibility
of oil contamination. This again contributes to the low
efficiency of the combined boiler and steam distribution
system. |
| Measure recommended: |
Pipe all the condensates to
suitably installed intermediate tanks before transferring
them to the soft tank for reuse in the boilers |
| Action taken: |
Intermediate tanks and a pump were
installed to collect and transfer the condensate to the
existing soft water tank for reuse in the boilers. This
resulted not only in fuel savings but also savings in water
treatment chemicals. |
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| VI. Temperature control for heating tanks |
| Audit findings: |
Although the required heating
temperature of the tank farms is only 80°C, due to
continuous charging of the steam the temperature raises
up to 95°C. The rise between 80°C and 90°C not only
contributes to energy wastage but also affects the quality
of the contents of the tank farm. |
| Measure recommended: |
A temperature controller system
should be provided to ensure no excess steam is charged
to the tank farm. |
| Action taken: |
A temperature controller system to cut in
and out the steam charging at 78°C and 80°C respectively
was installed. This can be considered as good energy
management practice. |
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| VII. Replacement of steam ejectors with vacuum pump
in PC1 bleacher unit |
| Audit findings: |
It was noticed that steam ejectors were
used to create the 70 Torr vacuum pressure in the
bleacher. This indirect method of converting steam
pressure to create vacuum is highly energy inefficient. |
| Measure recommended: |
Outsource for suitable system
that will create direct vacuum pressure. |
| Action Taken: |
A water seal ring type vacuum pump,
which is a proven energy efficient method for creating
vacuum pressure, is installed. |
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Result
The energy and cost savings as well as the CO2 reduction
achieved from the implementation of the above ECRMs is shown
in the following table. On the whole, steam consumption at
PCEO was reduced to 35 metric tonnes/day from the above
schemes.
Energy Cost
reduction |
Type
of
Invest-
ment |
Fuel
Savings
GJ/yr |
CO2
Reduction
t/yr |
Capital
Expen-
diture
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Annual
Cost
Savings
RM/yr
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Payback
time
(yr) |
Use of low pressure steam for tank farm
heating |
low cost |
2665 |
197 |
60,900 |
71,152 |
0.9 |
Pressure reduction valve for distillation
vacuum system |
low cost |
6,504 |
481 |
28,000 |
122,551 |
0.2 |
| insulation improvement |
low cost |
10,789 |
798 |
47,000 |
203,275 |
0.2 |
| Steam trap saving maintenance |
low cost |
4,789 |
325 |
77,500 |
78,725 |
1.0 |
| Condensate recovery |
low cost |
2,943 |
218 |
118,000 |
73,964 |
1.6 |
| Temperature control for tank farm
heating |
low cost |
1,896 |
140 |
23,600 |
34,648 |
0.7 |
Replacement of steam ejectors with vacuum
pump in bleacher |
low cost |
5,188 |
384 |
45,000 |
96,166 |
0.5 |
Total |
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34,380 |
2,544 |
400,000 |
680,964 |
0.6 |
Project Two : Cooling Tower Modification
Background
Seven cooling towers are located strategically in the fractionation, physical refining
and soap noodles plants. Cooling water is used mainly in crystallisers,
heat exchangers for cooling process fluids, compressor intercoolers and after
coolers and condensers. The performance of the cooling towers in the
fractionation plant was investigated and it was found that energy savings of 25
percent could be achieved by implementing thermal efficiency improvement
measures in this area.
Project Implementation
The following weaknesses were found at the cooling towers:
| i |
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The cooling towers were designed for 38°C return water temperature
and 30°C cold-water temperature at 27°C wet bulb temperature.
However, as against design temperature drop of 8°C, the actual cooling
was 5°C at 26°C wet bulb temperature. Therefore, the cooling load
achieved was only 60 percent of the design capacity. |
| ii |
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The liquid to gas (L/G) ratio was at 0.8 and 0.86 for cooling tower no.1
and 2.67 for cooling tower no.2. The recommended L/G ratio for tropical
climatic condition is between 1.0 and 1.1. The L/G ratio can be improved
by increasing the blade angle of the fans to increase the flow rate. |
| iii |
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Due to lower differential temperature, 3 cells were in use to get the
desired heat duty. |
The poor performance of the cooling towers
was due to the condition of the fills and
bad distribution of water. The fills are also
broken and displaced from their position
due to sagging. The combined effect of
these defects streams the water through the
cooling tower instead of being broken into
fine particles, which is a pre requirement for efficiency in heat removable from the returned hot water.
The improvements to the cooling towers
are being carried out in phases. The existing
seven wooden fills were replaced with
PVC fills whereas the FRP fan blades have
replaced aluminium fan blades as they are
lighter and provide effective blade angle
management. The blade angle of the fan was fixed at around 16°C to maintain an optimum air velocity of 9m/s.
Project Three: High Efficiency Motors
Background
High Efficiency Motors (HEMs) are
generally two to four percent more energy
efficient than standard motors. The
paybacks on HEMs are high when they are
incorporated during the initial installation
stages of the plant. However, replacing an
existing standard motor just before its life
cycle can justify the HEM option. Apart
from this, HEMs can be considered as a
preference instead of rewinding an existing
standard motor. Usually the loss in efficiency resulting from rewinding amounts to two to three per cent.
Project Implementation
At PCEO, a programme to replace the existing
standard motors to HEMs was started
in 1994 in a phased manner. The replacement
was done in stages and as of today,
most of the standard motors in the plants have been replaced by HEMs. Though the purchase price of
HEMs is about 20 percent more, PCEO achieved a significant
decrease in the electricity consumption over the years. According
to them, the top management was instrumental in the success
of this programme, as they believed the additional price
(or premium) could be repaid by the energy cost savings from
the motors with higher efficiencies.
The economic feasibility of investing in a new HEM is calculated
using a common method called “simple payback”.
| Simple payback (yr) = price premium/electricity cost savings |
An example of such calculations is shown in the table below for one of the existing standard motors that was replace recently
NO |
Item |
Unit |
Figure |
| 1 |
Base data |
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1.1
1.2
1.3
1.4
1.5
1.6 |
Motor size
Efficiency of standard motor (at 75% full load)
Efficiency of HEM (at 75% full load)
HEM price premium
Operating hours
Average
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kW
%
%
RM
hr/yr
RM/kwh |
75
91.50%
93.90 %
2,450
8400
0.22 |
| 2 |
Post implementation results |
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2.1
2.2
2.3
2.4 |
Reduced power demand
Annual power consumption saved
Electricity cost savings
Simple payback time |
kW
kWh/yr
RM/yr
yr |
1.57
13198 2904
0.84 |
Table 2: Sample calculation
The total investment cost for the replacement of all the existing
standard motors to HEMs was RM400,000. This investment
was quickly recovered within four years.
Project Four : Energy Monitoring & Targeting
Background
As a management driven activity, the company has
implemented a Monitoring and Targeting (M&T) system to
support the Birla Group’s World Class Manufacturing (WCM)
philosophy – If you can’t measure, then you can’t manage.
According to Pan-Century’s joint president Mr. S.C Jain, the M&T exercise directly detects abnormalities for immediate
remedial actions. This in turn results in energy savings, which
otherwise would not have been realised due to the delay in
detection of the same manually.
Norms are established for consumption trends and weekly
targets are set and monitored closely.
Every month, the
established figures are compared against the actual
consumption or output at the management meetings. Follow
up actions for abnormalities are addressed in the meetings.
The findings and the analysis of the data gathered from the
M&T system are reported to the headquarters for further
scrutiny. If targets are not met, justification is sought and peer
factories will be contacted for assistance. Otherwise, the
company strives to improve its operations to meet the set
targets.
Project Implementation
The M&T system is part of the parent company’s Purta system,
which has been in practice for years in all aspects of
manufacturing and performances. It is a benchmarking system
established based on design point consumption values. These
are ideal values computed for every set of production
parameters such as material inflow, product output, utility
consumed and waste generated. At PCEO, M&T is carried out
plant wide and at sub-process levels. The company is in the midst of completing the installation of
an online monitoring system for energy consumption. Phase
One of the project has been completed with the installation of
the metering equipment at every supply and consumption point.
The second phase, involving the centralisation of the electronic
energy data feedback and reporting system through local
network, is ongoing. The company has purchased several
metering equipment such as the maximum demand controller,
which was installed in April 2003; kWh meters; steam flow
meters and the chiller load controller. Installation is being done
in-house.
Project Implementation
The total cost of metering is approximately RM17,000 for the
maximum demand controller (RM3,000); steam flow meter
(RM12,000 per unit) and chiller load manager (RM 2,000).
No expenses were incurred for the installation and
commissioning or the development of the M&T software as
they were done entirely by the staff.
Management-driven commitment towards EE
At a recent interview, Pan-Century vice president (Engineering) Mr. P. R. Goyal
explained that energy efficiency is deployed through the company’s policy to
attain total customer satisfaction at minimum cost. He said: “Energy, which
cost the company RM2 million monthly, is one of the cost components that can
bring maximum return on investment related to energy efficiency. We are also
committed to a greener environment through the efficient use of natural
resources,” Mr. Goyal added.
This high level commitment was affirmed by Mr. Jain. He explained that the
management would approve EE projects even though some of them had long
payback periods. He said the determining factor in approving such projects is
the potential for plant improvements as well as the contributions towards social
and environmental benefits. The company has approved self-financing for many
low- and high-cost EE improvement projects in the past. Now the company is
totally convinced that such projects are not only viable but also beneficial to
the company. Mr. Jain emphasised, “There are no restrictions to the budget
allocation. As long as we are convinced of the overall benefits to the company,
an energy efficiency project will be approved immediately.”
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