Chemicals are the foundation of many of the products we use daily. Products from chemical facilities are used in everything from cleaners and solvents to telecommunications and biotechnology. 
 
The U.S. chemical industry is the second largest energy-consuming enterprise in the U.S., accounting for almost 30 percent of all U.S. industrial energy consumption. However, the U.S. Department of Energy has projected that with significant focus on new technologies, the chemical industry can achieve a 30 percent reduction in energy, water use, and toxic and pollutant dispersion per unit of output by 2020. 
 
Here are some measures that can help reduce energy usage in your chemical plant:

• Increase steam system efficiency. Opportunities for increasing the efficiency of most industrial steam systems fall into three categories: generation, distribution and recovery.

During generation, ways to reduce losses include minimizing excess combustion air, cleaning boiler heat transfer surfaces and considering using high-pressure boilers with backpressure turbine generators. It is also helpful to improve water treatment to minimize boiler blowdown. Adding or restoring boiler refractory and optimizing the deaerator vent rate helps reduce losses further. 
 

Distribution losses can be minimized by repairing steam leaks and minimizing the amount of vented steam. You should ensure that piping, valves, fittings and vessels are well insulated. It is very important to implement a steam-trap maintenance program because significant steam is frequently lost through failed traps. Isolate steam from unused lines and use backpressure turbines instead of pressure-reducing valves. (See more on steam traps below.)
 

Energy losses from steam recovery can be reduced by optimizing condensate recovery. In this case, use high-pressure condensate to make low-pressure steam. Install heat recovery equipment such as feedwater and condensing economizers and recover energy from boiler blowdown or from wastewater streams.

• Inspect steam traps regularly and repair or replace any failed or leaking steam traps.  A steam trap holds steam in the steam coil until the steam gives up its latent heat and condenses. In a flash tank system without a steam trap (or a malfunctioning trap), the steam in the process heating coil would have a shorter residence time and not completely condense. The uncondensed high-quality steam would then be lost out of the steam discharge pipe on the flash tank. 
   
  Comparing the temperature on each side of the trap, one can easily check steam trap operation. If the trap is working properly, there will be a large temperature difference between the two sides of the trap. A clear sign that a trap is not working is the presence of steam downstream of the trap. Nonworking steam traps allow steam to be wasted, resulting in higher steam production requirement from the boiler to meet the system needs. It is not uncommon that, over time, steam traps will wear and no longer function properly.
   
• Analyze flue gas for proper air/fuel ratio to improve combustion efficiency of boilers.  Adjusting the combustion system air-fuel ratio as needed to reduce the amount of excess air passing through the boilers can improve combustion efficiency. To determine the percent excess air or excess fuel at which a combustion system operates, you have to start with the correct mixing proportion air/fuel ratio. This is also known as the perfect, ideal or stoichiometric fuel ratio. At this ratio, the fuel burns efficiently without any excess of either fuel or air left over. However, if insufficient air is supplied to the burner, unburned fuel, soot, smoke and carbon monoxide exhausts from the boiler, resulting in heat transfer surface fouling, pollution, lower combustion efficiency, flame instability and a potential for explosion. To avoid such inefficient and unsafe conditions, boilers should operate at an excess air level. 
   
• Insulate steam/hot water lines.  Energy is used to either heat or boil water from the boiler, but when this energy is transferred through uninsulated pipes, it is lost to the atmosphere. Heat transfer through the pipes to undesired places means a larger load is being placed on the boiler, thus consuming more energy. This can be alleviated by simply insulating the pipes, which is rather inexpensive. 
   
• Use high efficiency electric motors. Electric motors are considered the work horse in many industrial applications, often operating for extended periods of time and consuming significant amounts of energy in the process. Not all motors operate with the same efficiency. When installing new motors, consider using high efficiency motors on all units one horsepower or greater. This is increasingly important for motors that operate for extended periods of time. 
   
• Eliminate leaks in compressed air lines and valves.  Air leaks around valves and fittings in compressed air lines can represent a significant energy cost in manufacturing facilities. Sometimes up to 20 percent of the work done by the compressor is used to make up for losses from air leaks. Therefore, air leak elimination should be a priority for any industrial facility. Sonic or infrared testing devices can be used as cost-effective tools for determining air leak locations. 
   
• Reduce the pressure of compressed air to a minimum.  Significant energy savings can be realized by reducing the air pressure used in compressed air systems. Often, air is compressed to a higher pressure than the air-driven process equipment actually requires. By adjusting compressor output to the proper air pressure, you can save energy with little or no impact on the air-driven process equipment. For additional savings, make sure that compressed air systems are shut down when not in use, especially at night and on weekends. 
   
• Recover waste heat from equipment. Consider installing heat recovery systems to make use of heat energy that otherwise would be lost to the surroundings. Heat recovery systems use hot media (typically air or fluids) leaving a process to preheat other, or sometimes the same, media entering the process. Energy that otherwise would be lost does useful work. Waste heat can be recovered from a variety of different types of equipment and processes, such as compressors, furnace and boiler exhaust, and hot liquid blow-downs. Blow-down heat recovery can reduce a boiler's fuel use by 2 to 5 percent. 
   
• Repair and eliminate steam leaks. Significant savings can be realized by repairing leaks in steam and condensate return lines. Steam line leaks result in higher steam production requirements from the boiler to meet the system needs. Condensate return lines that are leaky return less condensate to the boiler, thus requiring more energy to heat cooler make-up water than hot condensate return water. Leaks most often occur at the fittings in the steam and condensate pipe systems. 
   
• Install compressor air intakes in the coolest locations.  Where possible, run the intake for air compressors to the outside of the building, preferably on the north, shaded or coolest side. Typically, outdoor air temperatures are usually well below that in the compressor room, so it pays to take in cool air from outside. The energy savings potential in lowering the air intake temperature results from the fact that colder air is denser. Therefore, the compressor does not need to work as hard to obtain the desired pressure. 
   
• Eliminate or reduce compressed-air processes.  Compressed air generation is one of the most expensive processes in an industrial facility. When used wisely, it can provide a safe and reliable source of power for key industrial processes. But compressed air is often used for processes in which other methods would be much more efficient. Consider using alternative methods of power for processes, such as cooling, agitating liquids, moving product or drying. 
   
• Replace T12 fluorescent lamps with higher efficiency T8 fluorescent lamps and electronic ballasts. Retrofitting ceiling lighting with higher efficiency T8 lamps and electronic ballasts is a cost-effective way to reduce energy consumption. Depending on the ballast used, the T8 lamp often delivers the same lumen output for 20 to 40 percent fewer watts than T12 lamps. The benefits of installing higher efficiency T8 lamps and electronic ballasts include a decrease in energy consumption and costs, an increase in light quality and longer lasting lamps, which means reduced maintenance costs. 

Before installing higher efficiency lamps or ballasts, measure the light levels at each working height level for each area of the facility to determine whether more or less light is required. Suggested light levels are published by the Illuminating Engineering Society of North America. Also consider using T8 fluorescent lighting in high-bay applications that may currently use metal halide or high-pressure sodium fixtures for increased energy efficiency.

• Replace incandescent lamps with compact fluorescent lamps (CFLs). CFLs are a more energy-efficient lighting source than incandescents, typically using 75 percent less energy and lasting 10 times as long while producing 90 percent less heat. 
   
• Install ENERGY STAR^®-qualified exit signs to replace signs with incandescent or fluorescent lamps. Exit signs that have earned the ENERGY STAR rating operate on five watts or less per sign compared to standard signs, which can use as much as 40 watts per sign. One ENERGY STAR®-qualified exit sign alone can save about $10 annually on electricity costs and can last up to ten years without a lamp replacement, compared to less than one year for an incandescent.
   
• Install automated lighting systems, controls or sensors to reduce interior and exterior lighting energy costs. Lighting controls such as dimmers, timers and motion sensors may be used in closets, restrooms, offices, storage spaces and other areas that are not in constant use. These relatively inexpensive devices can help ensure that lights are turned off in areas that are not in use. It is recommended that lighting controls be inspected periodically to be sure that they are operating properly.