Large U.S. plants can save millions of dollars in energy and maintenance costs each year by improving the energy efficiency of their steam or process heating systems. This was one of the major findings of U.S. Department of Energy (DOE) Energy Experts and plant assessment teams when they evaluated the energy efficiency of industrial steam or process heating systems in 200 large, energy-intensive U.S. plants in 2006.
In the Winter 2007 issue of Energy Matters, we described the top 10 energy-saving recommendations in terms of how frequently they were made in all the plant energy assessments conducted in 2006. Since then, energy-efficiency specialists in the DOE Industrial Technologies Program (ITP) and at Oak Ridge National Laboratory have analyzed how much energy and money those plants could save by following the recommendations in their Save Energy Now energy assessments. They also looked at potential emission reductions and other benefits. The full report on the 2006 assessments is available on the Results page of the Save Energy Now Web site.
Tables 1 and 2, which are based on the report's findings, list the top five money-saving recommendations among all those made for industrial process heating systems and the top five for steam systems, out of about 30 recommendations made for each type of system. The tables also include the potential natural gas savings and estimated environmental emissions reductions associated with each recommendation.
Following each table are links to ITP resources, such as tip sheets, produced by technical experts in energy-efficient industrial systems. These resources, and those listed at the end of the article, can help you start to Save Energy Now in your own plant.
Table 1 shows the top five potential money-saving recommendations made in the 2006 Save Energy Now energy assessments that focused on improving process heating systems.
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Table 1. Top Five Money-Saving Recommendations for Process Heating | |||
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Recommendation from 2006 Save Energy Now Process Heating Assessments |
Total Potential Cost Savings |
Total Potential Natural Gas Savings |
Total Potential Reductions in Carbon Dioxide |
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Recover and use heat from industrial furnaces |
$20 million |
1 million |
182,000 |
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Use heat cascading |
$16 million |
2 million |
142,000 |
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Use proper heating methods |
$13 million |
1 million |
74,000 |
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Use proper furnace insulation and maintenance techniques |
$12 million |
1 million |
124,000 |
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Reduce flue gas oxygen content |
$9 million |
878,000 |
111,000 |
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*Rounded to the nearest thousand or million. | |||
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Details and Resources for Process Heating |
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Some of the following documents are available as Adobe Acrobat PDFs. Download Adobe Reader. |
1. Recover and use heat from industrial furnaces:To make use of the considerable heat from industrial furnaces, see these tips:
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2. Use heat cascading:The heat from flue or exhaust gases in higher temperature processes can be used to supply heat to lower temperature processes, as described in this tip:
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3. Use proper heating methods:To increase your process heating savings by replacing inefficient, uneconomical methods with efficient, economical systems, see these tips:
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4. Use proper furnace insulation and maintenance techniques:To avoid localized losses in furnaces, consider these tips:
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5. Reduce flue gas oxygen content:To lower the oxygen levels in exhaust gases in order to raise available heat levels and improve energy efficiency, see this tip:
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Table 2 shows the top five potential money-saving recommendations made in 2006 during Save Energy Now energy assessments that evaluated industrial steam systems.
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Table 2. Top Five Money-Saving Recommendations for Steam Systems | |||
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Recommendation from 2006 Save Energy Now Steam System Assessments |
Total Potential Cost Savings |
Total Potential Natural Gas Savings |
Total Potential Reductions in Carbon Dioxide |
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Reduce steam demand |
$89 million |
8 million |
1 million |
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Use alternate fuel |
$78 million |
14 million |
376,000 |
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Improve boiler efficiency |
$43 million |
4 million |
284,000 |
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Add or modify backpressure steam turbine |
$34 million |
130,000 |
166,000 |
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Improve condensate recovery |
$24 million |
2 million |
151,000 |
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*Rounded to the nearest thousand or million. | |||
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Details and Resources for Steam Systems |
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Some of the following documents are available as Adobe Acrobat PDFs. Download Adobe Reader. |
1. Reduce steam demand:For information about opportunities for improving the energy use and performance of steam systems as well as the benefits of a systems approach, see this resource from ITP:
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2. Use alternate fuel:To switch to a fuel with a higher theoretical combustion efficiency and save money on fuel, see these tips:
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3. Improve boiler efficiency:To reduce boiler losses and use less fuel to achieve the production rate you need, review these tips:
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4. Add or modify a backpressure steam turbine:To increase your total steam usage and potentially reduce your overall energy costs, see these tips:
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5. Improve condensate recovery:To increase the condensate returned to the boiler and supply hotter water to the boiler feedwater system, try this tip:
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To review the entire report on the 2006 plant assessments, Results from the U.S. DOE 2006 Save Energy Now Assessment Initiative, you can visit the ITP Save Energy Now Web site or order the CD. And for more information about how to improve your plant's process heating or steam system efficiency, see the following ITP resources.
And for more information about Save Energy Now energy assessments, including activities planned in 2007, visit the Save Energy Now Web site.