|To read "Part II: HVAC, Boilers and Cogeneration," click here.
Pharmaceutical manufacturing plants in the U.S. spend nearly $1 billion each year for the fuel and electricity they need to keep their facilities running (Figure 1, below). That total that can increase dramatically when fuel supplies tighten and oil prices rise, as they did last year.
Improving energy efficiency should be a strategic goal for any plant manager or manufacturing professional working in the drug industry today. Not only can energy efficiency reduce overall manufacturing costs, it usually reduces environmental emissions, establishing a strong foundation for a corporate greenhouse-gas-management program.
|Figure 1. U.S. drug manufacturing plants spend nearly $1 billion each year for the fuel and electricity needed to run their facilities.
For most pharmaceutical manufacturing plants, Heating, Ventilation and Air Conditioning (HVAC) is typically the largest consumer of energy, as shown in Table 1 below.
This two-part series will examine energy use within pharmaceutical facilities, summarize best practices and examine potential savings and return on investment. In this first article, we will focus on efficient use of motors, drives and pumps, both for process equipment and compressed air systems. Part 2, to be published in May, will focus on overall HVAC systems, building management and boilers.
Research in this article was first published last September, in an extensive report developed by Lawrence Berkeley National Laboratories for the Energy Star Pharmaceutical Focus. Established in January 2005, this group of pharmaceutical industry corporate energy managers is working to develop resources and tools to foster improved energy efficiency within the industry.
The Environmental Protection Agency (EPA) is also working with Argonne National Laboratory to develop an energy performance benchmarking tool for pharmaceutical plants (see "Will Pharma Wear the Energy Star?"). For more information, please visit www.energystar.gov.
|Table 1. For most pharmaceutical manufacturing plants, HVAC is typically the largest consumer of energy.
A “systems approach” to motors and drives
Motors and drives are used throughout the pharmaceutical industry to operate HVAC systems, to drive laboratory or bulk manufacturing equipment, including mixers, pumps, centrifuges and dryers, and to move and operate filling and finishing equipment.
In order to prioritize areas for improvement, it is best to take a “systems approach” and look at the entire motor system, including pumps, compressors, motors and fans, instead of examining each component individually. The following steps should be taken:
- Locate and identify all motor applications (e.g., pumps, fans) in the facility;
- Document their conditions and specifications;
- Compare your requirements vs. the actual use of the system to determine the energy consumption rate; this will help determine whether the motors have been properly sized;
- Collect information on potential upgrades or updates to the motor systems, including implementation costs and potential annual savings;
- If you do elect to upgrade or update any equipment, monitor its performance over time to determine actual costs savings .
Other essential issues for energy efficient operation include:
- This can save from 2% to 30% of total motor system energy use .
- Preventive measures consider electrical conditions and load, minimize voltage imbalance and include motor ventilation, alignment and lubrication.
- Predictive measures observe ongoing temperature, vibration and other operating data to determine when to overhaul or replace a motor before it fails.
- Ensuring that motors are properly sized, and that oversized motors are replaced, can save, on average, 1.2% of total motor system electricity consumption . Generally, whenever peak loads can be reduced, so can motor size.
- Belt drive replacement.
- Roughly 4% of pumps have V-belt drives, many of which can be replaced with direct couplings to save energy . Savings associated with V-belt replacement are about 4% of total motor system electricity consumption, and costs are estimated at $0.10/kWh-saved with payback within two years.
- Rewinding vs. replacement.
- Replacing an old motor with a high-efficiency motor is often a better choice than rewinding a motor. Currently, there are no quality or efficiency standards for rewinding, and motor efficiency typically decreases from 2% to 25% after rewinding.
When considering whether to rewind a motor or to replace it with a higher-efficiency model, consider the following rules of thumb: