Replacing Compressed Air with Alternatives

Although compressed air is an expensive energy carrier, because it is clean, readily available, and simple to use it is often chosen for applications in which other methods or sources of air are more economical. To reduce compressed air energy costs, alternative methods of supplying low-pressure end uses should be considered before using compressed air in such applications. Many alternative methods of supplying low-pressure end uses can allow a plant to achieve its production requirements effectively.

Examples of areas, where compressed air use can be eliminated include the following (US DOE, 2004): 

Existing Low Pressure End Use  Potential Alternatives and Reasoning
Open blowing Open-blowing applications waste compressed air. For existing open-blowing applications, high efficiency nozzles could be applied, or if high-pressure air is not needed, a blower or a fan can be used instead (US DOE, 2004).
Mixing Mechanical methods of mixing typically require less energy and can reduce compressed air demand (US DOE, 2004).
Parts cleaning Low-pressure blowers, electric fans, brooms, and high- efficiency nozzles are more efficient for parts cleaning than using compressed air to accomplish such tasks (US DOE, 2004).
Air motors and air pumps The tasks performed by air motors can usually be done more efficiently by an electric motor - except in hazardous environments or in applicaitons require high-precision. Similarly, mechanical pumps are more efficient than air-operated double diaphragm pumps (US DOE, 2004; Worrell et al., 2008. p.33). 
Cooling electrical cabinets Instead of using compressed air vortex tubes, air conditioning fans can be used Worrell et al., 2008. p.33).
Vacuum creation Instead of having compressed air venturi method, where a high-pressure air flow past an orifice to create vacuum, a vacuum pump system should be used (Worrell, et al., 2008. p.33)

 

Development Status Products
Commercial

Replacing Compressed Air with AlternativesCosts & Benefits

Parent Process: Compressed Air Systems
Energy Savings Potential

This measure is estimated to offer following improvement potentials:
• 20% for low efficiency base cases;
• 13% for medium efficiency base cases;
• 3% for high efficiency base cases.

Electrical and primary energy savings potential of this technology for diffierent countries is estimated as following (UNIDO, 2010): 

  Final (GWh/y) Primary (TJ/y)
US 3479 38196
Canada 918 11439
EU 3045 28605
Thailand 467 4703
Vietnam 210 3003
brazil 722 8051
CO2 Emission Reduction Potential

Total emisson reduction potential, as kt CO2/y for different countries are estimated as (UNIDO, 2010): 

US 2096
Canada 456
EU 1327
Thailand 243
Vietnam 103
brazil 106

Costs

Estimated typical capital costs of this measure for different system sizes (S) are:
• US $2000  for S < 37 kW;
• US $4000 for 37 kW < S < 75 kW;
• US $7000 for 75 kW < S < 150 kW;
• US $12000 for 150 kW < S < 375 kW;
• US $15000 for 375 kW < S < 745 kW; (UNIDO, 2010)

Cost of conserved energy, expressed as US $/MWh-saved, in different countries are estimated as following: (UNIDO, 2010)

US 49.9
Canada 51
EU 56.3
Thailand 30.3
Vietnam 30
brazil 30.4

Numerous case studies across all U.S. industries estimate the average payback period for this measure to be only slightly higher at less than 9 months.

Parent Process:
Energy Savings Potential
CO2 Emission Reduction Potential

N/A

Costs

Replacing Compressed Air with Alternatives Publications

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