One of the most significant opportunities for Brit to reduce energy consumption will likely be in motors that drive pumps to move fluid throughout the refining process.
Replacing single-speed motors with variable-speed drives has a tremendous potential for cost and energy savings by reducing friction in the pump system.
Here’s why: The centrifugal pump is the second-most widely used type of mechanical equipment in the world – outnumbered only by electric motors. Pumps are prime candidates for major energy savings, since the power required varies as the cube of the speed ratio (i.e., cutting cut speed in half reduces the required power to one-eighth of its original value).
In relative terms, pumps are efficient machines; most 
typically operate near 75% of their Best Efficiency Point (BEP). But a pump is very sensitive to how it is operated, and it is the pumping system that has the greatest influence on a pump’s energy use. Energy can account for as much as 75% of a pump's total cost of ownership.
A pump converts mechanical energy into pressure energy, which is imparted into a fluid, which creates flow. If an efficiently designed pump is operated in an inefficient manner, the pumping system will operate at far below the pump’s Best Efficiency Point (BEP) (Figure 1).
A great source of inefficiency in most industrial pumping systems is the control valve, which is used to throttle flow – resulting in significant energy loss due to the friction across the valve (Figure 2).
By incorporating a variable-speed drive, the friction caused by throttling is eliminated (Figure 3). The drive itself provides only as much power as is needed to generate the desired flow.
In addition to improving energy efficiency, variable-speed drives have other benefits. By allowing gradual and controlled changes in flow, they reducing air holes and resonance frequencies, and eliminate the hammer effect.
Variable-speed drives have been in industrial use for more than 20 years now and have accumulated a track record of reliability and efficiency. Their use could be a significant part of Brit’s effort to meet his company’s new sustainability objectives.
William Livoti is Senior Principal Engineer at Baldor Electric Co., a member of the ABB Group. With more than 30 years experience in the pump industry, Livoti has worked for several pump and mechanical seal OEMs, and as Corporate Principal Engineer for Balance of Plant Equipment at a large power utility company, where among other responsibilities he was accountable for asset management, life cycle performance, system assessment, failure analysis and plant efficiency. He has just completed a book on System Optimization Guidelines with the Hydraulic Institute and is currently preparing a book on Power Plant Process Guidelines for Pumping Systems. His primary responsibility at Baldor includes industry specific applications/solutions, failure analysis and R&D for motors, drives, enclosed gearing and bearings as they apply to power generation and fluid handling with a focus on energy efficiency, life cycle performance and asset optimization.