It is encouraging to see the improvements in energy efficiency in the petrochemical industry in Singapore. These efforts started several decades ago and are not letting up. Narendra Aggarwal explains in an article on The Business Times website.
Striving to better energy performance
PROACTIVE in energy-conservation efforts since the beginning of its operations in the 1980s, Petrochemical Corporation of Singapore (PCS) Private Limited has bagged two awards this year. It has been awarded the Excellence in Energy Management category and received Honourable Mention in the Best Practices award category. PCS monitors its energy efficiency through established key performance indicators (KPI), striving to maintain its position in the top quartile in the worldwide benchmarking study among similar plants, while continuing to implement projects to maintain and improve its energy performance.
The company is the pioneer of the petrochemical industry in Singapore and the region. It was jointly established in 1977 by the Singapore government and Japan-Singapore Petrochemical Co Ltd (JSPC) led by Sumitomo Chemical.
Lucas Ng, general manager of plant at PCS, says: “Feedstock costs are subject to market conditions and fluctuate according to crude oil prices, and so is energy. What plant operators like us can control is how to manage and improve the energy efficiency performance and therefore reduce the unit cost of products in order to be more competitive. Reduction in energy consumption certainly reduces the plant’s greenhouse gas emissions, especially carbon dioxide, which is known to cause global climate change.”
There are many benefits of being energy efficient.
“It not only reduces the unit cost of producing a product but also increases production rate by reducing wastage in materials. For example, the by-product ethane can be recycled to become valuable ethylene product. Otherwise, ethane has to supplement as fuel if it is not energy efficient. Such an energy-efficient process would improve competitiveness and market share,” he adds.
The practical approaches include improving operational controls by having automation controls such as advanced process control.
Another way is to monitor the efficiency of major equipment through online real-time monitoring of energy performance for large energy consumers such as the main compressors of ethylene plant that consumes a large proportion of the plant’s energy.
Other steps that can be taken are to perform predictive and risk-based maintenance to ensure the equipment is operating efficiently via timely cleaning of fouling materials that retard heat-transfer performance.
Mr Ng suggests regular assessment of energy efficiency improvement opportunities through PDCA (plan-do-check-act).
A recently completed energy-efficiency initiative by PCS is the installation of the overall utilities optimiser. This is an additional computer software system dedicated to optimising the steam and power system in order to reduce fuel consumption and thus reduces plant-wide overall energy consumption.
The company also installed an additional cracking furnace feedstock preheater to preheat feedstock using residual heat from quenching water system. Otherwise, the residual heat of quench water has to be cooled by seawater heat exchanger to meet process requirement, ie energy is lost to the sea.
Another step was to improve the design of vapour and liquid distributors in the quench tower to reduce the temperature of process gas to be compressed in order to reduce power consumption (higher gas temperature means larger gas volume that requires higher energy consumption).
Mr Ng says the initiatives under implementation are: Additional heat exchangers for improved heat recovery, which are under construction. Replacing existing furnace coils with new configurations for improved selectivity of products, ie higher value products with the same energy consumption. Replacing existing older generation compressors with lower thermodynamic efficiency installed more than three decades ago by new higher-efficiency machines.
The company has benefited from all these initiatives through greater awareness of staff on energy efficiency and energy conservation, thus reducing unit cost of products and increasing production.
Mr Ng says PCS plans to promote energy efficiency through continuous improvement in its ongoing and proactive energy conservation efforts.
Mr Ng says that the award for Excellence in Energy Management recognises PCS’s efforts and approach to continuously improve energy performance and maintain “Best-in-class” status. The Honourable Mention in the Best Practices category recognises PCS members’ teamwork in energy conservation efforts to develop and implement initiatives.
“For the past many years, PCS has been consistently striving its best to stay competitive by improving all aspects of its operations. These include safe, stable and reliable operations through excellent occupational safety as well as process safety performance,” says Mr Ng.
PCS has its comprehensive facility reliability management system as part of process safety excellence. Energy efficiency has been embedded in the bases of its operations since the beginning.
As a winner, the experiences could be shared to assist others to improve their energy efficiency,” he adds.
As the pioneer of the petrochemical industry in the region, PCS provides basic feedstock for the polymer and chemical industry in Singapore and the region. Its production capacity increased to more than threefold through debottlenecking, expansion and diversification. PCS is currently owned equally by JSPC and QSPS, a joint venture between Qatar Petroleum International (QPI) and Shell Petrochemicals (Singapore) Pte Ltd.