Hydrocarbon Processing - February 2021 - 25

Special Focus

Digital Transformation
C. LAU, Schneider Electric, Houston, Texas

Reduce OPEX and improve sustainability through
digital energy optimization strategies
Oil and gas companies are looking for
quick ways to reduce OPEX amid the pandemic and oil and gas market crises. Initiatives to improve sustainability are further
intensifying this challenging environment.
Energy cost is about 30% of variable and
labor costs, the second largest expense following feedstock cost. Energy optimization is a key opportunity to reduce energy
cost and lower emissions.
Digital transformation solutions can
accelerate the return of energy optimization investments. By implementing digital
energy optimization strategies, an average-size refinery (200,000 bpd) or petrochemical plant can improve profitability
by an estimated $15 MM/yr-$30 MM/yr
and reduce carbon dioxide (CO2) emissions by 500,000 mtpy-900,000 mtpy:
the equivalent to taking 100,000-200,000
gasoline-fueled cars out of service.
Visualization and monitoring. Visualization and monitoring can be simple and
effective solutions to reduce energy costs.
Integrating various sources of energy data
and displaying them in key performance
indicators (KPIs) that operators can relate
to-and how their actions can impact the
company's overall objectives-enforces
accountability. An often overlooked basic
solution is automation loop tuning and
performance monitoring. Automation
loop performance monitoring ensures
that each control loop is performing to its
designed performance. A South African
chemical company was able to reduce its
steam cost by $3.6 MM/yr utilizing realtime accounting and visualization solutions.
Energy management and utilities
modeling. Using proven software tech-

nologies, such as advanced regulatory
control and advanced process control

(APC), can reduce variance of operational conditions. Once the process is achieving stable operation, the application of
real-time optimization allows the plant
to run close to its optimal target. The
benefits include energy conservation,
minimizing material consumption, maximizing throughput and reducing product
quality variance. A Japanese refinery reported a 5% reduction in energy cost using a real-time optimization strategy. The
largest Indian refinery reported a savings
of $7.2 MM through better visualization
and $5 MM via real-time optimization.
Variable speed drive. A variable speed

drive (VSD) is a simple energy-saving
solution that provides quick payback.
By using VSDs vs. on-off switch direct
across the line motor starters, up to 50%
of energy cost can be saved. Thousands
of pumps function in an average refinery,
and hundreds of fans in a liquefied natural gas (LNG) plant, so energy costs can

add up quickly. Pumps and motors are
often oversized, so more energy is being
consumed than is required. Most new
VSDs also have smart condition-based
monitoring capabilities that help improve
asset availability. The author's company's
remote electrical asset monitoring solutions helped a U.S. petrochemical plant
detect undersized VSDs and malfunctioning transformers that caused premature aging, allowing them to avoid unscheduled plant shutdowns.
Digital twin. Digital twins are a hot topic
today, but what would generate more return on investment (ROI) is using one
digital twin model for the entire lifecycle-from design to simulation, to engineering and commissioning, to operator
training, to operations and maintenance.
Digital twin for equipment monitoring is
an online asset monitoring strategy based
on the design vs. actual concept. It assists
operating sites to improve performance by
Optimize process

Energy optimization
Efficiency
Use energy more
efficiently

Reduce energy
cost and reduce
emissions

Sourcing
Acquire energy at
a lower cost

Improve visualization and monitoring
Enhance on line control and operation

Improve heat recovery

Improve heat integration

New process technology

New catalyst/new technology

Produce less expensive energy

Improve boiler turbine performance

Purchase less expensive energy

Balance supply and demand

Reduce waste heat and loss

Improve resource allocation
Optimize fuel mix
Contract management
Feedstock selection

Sustainability
Reducing emissions

Reduce CO2, C2H4 emissions

Incorporate sustainability
as optimization constraint

Increase low carbon
energy mix

Natural gas, renewables
electrification

FIG. 1. Manage the three elements of energy efficiency, sourcing and sustainability by adopting
a strategic comprehensive plan to help reduce energy cost and lower emissions.
Hydrocarbon Processing | FEBRUARY 2021 25

Hydrocarbon Processing - February 2021

Table of Contents for the Digital Edition of Hydrocarbon Processing - February 2021