Thermal Process Intensification in Industry
Authors: Joe Cresko, Ali Hasanbeigi, et al.
Thermal processing of materials, commonly referred to as process heating operations, involves supplying thermal energy to transform materials such as metal, plastic, rubber, limestone (cement), glass, ceramics, and biomass into a wide variety of industrial and consumer products. Industrial heating processes include melting, drying, heat treating, curing, forming, calcining, smelting, and other operations . Examples of common process heating systems include furnaces, ovens, dryers, heaters, kilns, and boiler/steam systems.
These equipment systems are operated over a broad range of temperature from 300°F to 3,000°F and require the use of heating systems (e.g., burners, electric heaters) to supply heat, a material handling system to transport materials through the heating system, advanced materials that can withstand high temperatures and challenging environments, controls, and other auxiliary systems.
Most heating systems use fossil fuels that are significant sources of GHG emissions. Their thermal efficiencies (i.e., ratio of energy used for the process material to gross energy input) range from as low as 15% to as high as 80%.
Thermal Process Intensification (TPI) includes all the transformative technologies and strategies that dramatically improve the performance (e.g. energy productivity, thermal efficiency, reduced GHG emissions, reduced number of process steps) of thermal processing systems to make manufacturing operations more productive, precise and efficient.
Global Efficiency Intelligence, LLC worked with US DOE’s Advanced Manufacturing Office and Oak Ridge National Laboratory to conduct an analysis and series of stakeholders consultation workshops on thermal process intensification in industry. The goals of the DOE Advanced Manufacturing Office Thermal Process Intensification Workshop were as follows:
• Identify R&D gaps and opportunities to facilitate transformative improvement in industrial thermal processes beyond current technologies and allow for entirely new methods for processing materials.
• Gain insight into new and innovative approaches to thermally intensify processes, reduce heat demand, harness waste heat, and use fuels and hydrocarbon feedstocks more efficiently.
• Identify the R&D pathways to thermal process intensification (TPI) with the highest potential for impact and adoption by the industrial sector.
• Define areas of research, development, and demonstration (RD&D) activities to accelerate development and application of emerging and transformative technologies to intensify thermal processes in industry.
The scope and focus of the workshop were defined to meet these goals. Based on the available data for energy use and GHG emissions, the industries that collectively use more than 80% of the total process heating energy consumption were selected as primary focus areas. The chosen industries were combined into the following four groups based on similarities in their thermal processes:
high-temperature metal processing (iron and steel industry, alumina-aluminum industry);
high-temperature nonmetal and mineral processing (cement and glass industry);
medium- to low-temperature thermal processing (food processing and pulp and paper industry as part of forest products sector);
hydrocarbon processing (petroleum refining and chemical industry).
Furthermore, all potential TPI technologies associated with the processes defined were considered as part of the workshop. Different types of TPI technologies possible in industrial thermal systems were categorized into four TPI pillars which are laid out as a framework in the Table below.
Source: This US DOE study