RECOGNISING the importance of using energy efficiently at its operations, ExxonMobil’s Singapore Chemical Plant (SCP) implemented a new technology to enhance energy performance at its aromatics facility. The success of this initiative won ExxonMobil a Best Practices honour at the EENP awards.
ExxonMobil has operated in Singapore for over 125 years and holds more than S$25 billion in fixed assets in the Republic. Its manufacturing facilities – SCP and the Singapore Refinery – make up the group’s largest integrated manufacturing complex in the world.
The SCP was first commissioned in 2001, and further expanded to more than double its capacity in 2013. Its ethylene capacity is now 1.9 million tonnes per year. Using ExxonMobil’s proprietary technologies, a broad range of feedstock can be processed at the plant before they are converted into higher-value products.
The SCP has three aromatics plants, which produce paraxylene, benzene and orthoxylene – building blocks for the manufacture of everyday consumer products such as clothing, transparent film packaging, screen protectors and synthetic leather.
In August 2017, ExxonMobil completed the acquisition of one of the world’s largest aromatics facilities on Jurong Island in Singapore; increasing its aromatics production in Singapore to over 3.5 million tonnes per year, including 1.8 million tonnes of paraxylene.
As part of its continual efforts to improve energy efficiency, ExxonMobil built a new “liquid phase xylenes isomerization” (LPI) unit that operates at low temperature, effectively reducing the energy consumed at its aromatics recovery unit, compared to the more traditional vapour phase xylenes isomerization (VPI) process.
Xylenes isomerization refers to a process that enables more paraxylene products to be produced. What’s more, LPI technology can be deployed in parallel with the existing isomerization processes at SCP, yielding debottlenecking opportunities.
“The project has led to a reduction in carbon emissions from the aromatics recovery unit as a result of less fuel gas consumed. The reduction in carbon emissions as a result is equivalent of about 4,500 cars being removed from Singapore’s roads each year,” said Raymen Chee, technical manager, ExxonMobil Singapore Chemical Plant.
“At ExxonMobil, we believe in the continuous innovation and employment of the latest technologies to improve our energy performance and reduce our carbon footprint,” he added.
Deploying LPI technology at an existing facility posed more challenges compared to implementing it in a new unit.
Among other obstacles, it meant working around existing space constraints, layouts and compatibility with existing equipment.
The team also had to undertake a thorough assessment to ensure that the new technology did not limit the unit’s overall throughput production.
GLOBAL ENERGY MANAGEMENT SYSTEM
The LPI project is one example of how ExxonMobil continues to leverage its Global Energy Management System (GEMS) to improve energy efficiency. The system, which won the 2017 Excellence in Energy Management award, is a result-oriented and systematic framework to identify energy performance opportunities in the groups operations, execute plans and continuously improve energy efficiency.
According to ExxonMobil, management leadership, organisational commitment and personal accountability work hand-in-hand to deliver these improvements.
ExxonMobil has been using GEMS to drive its efforts to manage energy use at its refineries and chemical plants worldwide since its launch in 2000 to identify and act on energy- saving opportunities.
A series of initiatives implemented in Singapore from 2002 to 2018 have led to gains in energy efficiency of over 25 per cent. These have resulted in the avoidance of carbondioxide emissions equivalent to taking more than 550,000 cars off off Singapore’s roads over this period.
