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.

PLANT 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

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 an RM 1.0 million venture. To date, the steam optimisation programme has alone resulted in an annual energy 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 conversation schemes heat recovery schemes and monitoring & targeting, which produced a total energy savings of RM320,000. PTM has agreed to do the study of compressed air system and chilled water system.

Project One: Steam System Optimisation

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 55 KL 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 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 degrees centigrade, which can be attained with low-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.

II. 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 vacuum circuits to maintain the steam supply pressure at 10 barg.

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 minimise 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 10OC after the rectification, not only saves energy but also creates a thermal-comfort working environment.

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.

Action taken: Suitable sized traps were provided and a strict steam trap checking procedure was implemented to detect faulty traps before installation.

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.

VI. Temperature control for heating tanks

Audit findings: Although the required heating temperature of the tank farms is only 80oC, due to continuous charging of the steam the temperature raises up to 95oC. The rise between 80oC and 90oC 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 78oC and 80oC respectively was installed. This can be considered as good energy management practice.

VII. Replacement of steam ejectors with vacuum pump in PC1 bleacher unit
of medium pressure steam (14.5 barg)

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

Results

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.

Table 1: Summary of energy savings.

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. The cooling towers were designed for 38oC return water temperature and 30oC cold-water temperature at 27oC wet bulb temperature. However, as against design temperature drop of 8oC, the actual cooling was 5oC at 26oC wet bulb temperature. Therefore, the cooling load achieved was only 60 percent of the design capacity.

II. 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. 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 16o to maintain an optimum air velocity of 9m/s.

Results

Due to the above modification in cells of cooling tower, the differential 20 temperature improved from 5°C to 7°C and one cell fan was stopped resulting in net power saving of 20 kW, equivalent to RM 35,000/year.

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 exiting 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 all 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".

An example of such calculation is shown in the table below for one of the existing standard motors that was replaced recently.

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.

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 at both plant wide and each sub-process levels. Below is a sample of the M&T format.

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.

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.

Results

M&T enables the company to monitor and verify the implemented energy saving measures and control energy and material wastage. In a short span of time, monitoring via the maximum demand controller resulted in more vigilance over energy consumption and immediate corrective actions, such as switching off the non-critical load.

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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