It is estimated that between 20 to 50% of industrial energy input is lost as waste heat in the form of hot exhaust gases, cooling water, and heat lost from hot equipment surfaces and heated products. As the industrial sector continues efforts to improve its energy efficiency, recovering waste heat losses generate cost savings, reduces environmental impact, and improves work flow and productivity.
Numerous technologies are commercially available for waste heat recovery and many industrial facilities have upgraded or are improving their energy productivity by installing these technologies, however these technologies are not being pursued to the fullest extent possible due to several barriers such a material constraints, and greater maintenance costs.
Below are current resources AMO is providing in the form of tools, training, technical documents and R&D that promote waste heat recovery (WHR).
Tools and related resources
- Process Heating Assessment Software Tool (PHAST) identifies WHR upgrade opportunities from process heating equipment such as furnaces, ovens, kilns, dryers and boilers in the areas of wall heat losses, heat storage and stack heat recovery.
- Steam System Modeling Tool (SSMT) with tutorial identifies WHR upgrade opportunities such as using stack and boiler blow down heat to preheat boiler make up water, preheat combustion air and or other plant processes.
- WHR related training as it relates to both Process Heating and Steam Systems (onsite and offsite)
- CHP Technical Assistance Partnerships
Waste heat recovery from process heating systems
- Energy Assessment Helps Kaiser Aluminum Save Energy and Improve Productivity
- AMO Waste Heat Recovery Technology Assessment QTR 2015
- Industrial Waste Heat Recovery: Potential Applications, Available Technologies and Crosscutting R&D Opportunities, Arvind Thekdi (E3M Inc.) and Sachin Nimbalkar (ORNL), ORNL/TM-2014/622, January 2014
- Waste Heat Recovery: Technology and Opportunities in U. S. Industry, details the state of waste heat recovery technologies and evaluates R&D needs for improving these technologies, prepared for DOE 2008
- Improving Process Heating System Performance: A Sourcebook for Industry
- Energy Use, Loss and Opportunities Analysis: U.S. Manufacturing & Mining describes the U.S. industrial sector and details the top opportunities for industrial energy savings, including several waste heat recovery opportunities (December 2004).
- Materials Selection Considerations for Thermal Process Equipment
- Check Heat Transfer Surfaces
- Install Waste Heat Recovery Systems for Fuel-Fired Furnaces
- Using Waste Heat for External Processes provides useful information needed to help evaluate the use of waste gases for heating secondary processes (2006).
- Waste Heat Reduction and Recovery for Improving Furnace Efficiency, Productivity and Emissions Performance details methods to maximize efficiency and productivity from industrial furnaces through equipment energy conservation techniques and waste heat recovery (November 2004).
- Metal and Glass Manufacturers Reduce Costs by Increasing Energy Efficiency in Process Heating Systems
- Seven Ways to Optimize Your Process Heat System
Waste heat recovery from steam systems
- Consider Steam Turbine Drives for Rotating Equipment
- Consider Installing a Condensing Economizer
- Flash High-Pressure Condensate to Regenerate Low-Pressure Steam
- Recover Heat from Boiler Blowdown
- Feed water Economizers for Waste Heat Recovery to reduce steam boiler fuel requirements by transferring flue gas heat to incoming feed water (January 2006).
- Use Low-Grade Waste Steam to Power Absorption Chillers outlines the benefits of absorption chillers (which can utilize low-grade waste heat) to replace motor-driven mechanical chillers (January 2006).
- Use Vapor Recompression to Recover Low-Pressure Waste Steam
- Use a Vent Condenser to Recover Flash Steam Energy
- Steam System Survey Guide provides technical information on several major opportunities to improve the efficiency and productivity of industrial steam systems. The guide covers: steam system profiling; identification of steam properties; boiler operations improvements; improvement of steam system utilization; and the determination of steam distribution system energy losses.
- Industrial Steam System Heat-Transfer Solutions This brief provides an overview of considerations for selecting the best heat-transfer equipment for various steam systems and applications
- CIBO Energy Efficiency Handbook to help owners and operators get the best and most energy-efficient performance out of their boilers and steam systems
AMO has carried out a good amount of work with CHP systems that involve bottom up waste heat recovery conversion to power.
Waste Heat to Power Market Assessment
AMO R&D on Waste Heat Recovery
- Waste Heat-to-Power in Small-Scale Industry using scroll expander for organic rankine bottoming cycle. Medium-grade waste heat can be converted to electric power using a novel, scalable scroll expander having an isentropic expansion efficiency of 75% to 80% for a broad range of organic Rankine cycle boiler pressures, condensing temperatures, and speeds. Estimates suggest the system would generate net income in three years and provide national energy savings of 0.90 TBtu/year just for natural gas from coffee roasting applications alone.
- High Thermal Conductivity Polymer Composites for Low Cost Heat Exchangers to speed the development of plastic heat exchangers, researchers will create a database of selected properties for thermally conductive plastics. Heat exchangers manufactured from polymer composites would have several advantages over metal heat exchangers, including lower weight, improved corrosion resistance, and compared to the current manufacture of metal heat exchangers, increased energy productivity and lower greenhouse gas emissions.