Energy Recovery from Waste Process Gas with Heat Pump in a Chemical Plant

This is an integrated energy efficiency project where the heat of process gas, released to the atmosphere at high flow but low temperature, is recovered using heat pump technology and reused within the same facility. The system was designed and implemented with a project-specific engineering approach to capture low-temperature waste heat potential that is not economically viable otherwise.

Project Information

• Industry: Chemical and Process Industries
• Project Type: Low-temperature waste heat recovery
• Core Technology: Heat pump and heat exchanger systems
• Project Model: EPC (engineering, procurement, construction, and commissioning)

Need and Project Rationale

Before the project, the facility had process gas released to the atmosphere at high flow but low temperature. Existing systems could not economically utilize this energy potential. Additionally, extra energy was required to preheat the process air at the inlet, increasing operational costs.

Under these conditions, a heat pump-based system was designed specifically to efficiently recover low-temperature waste heat.

Applied Engineering Solution

In the developed system, the heat from the waste process gas was captured through specially designed heat exchangers and transferred to the heat pump. The heat pump increased the temperature, and the recovered energy was used to preheat the inlet air in the same process.

The heat pump system operates at an approximate COP of 5.3 when considering only its own electricity consumption.

Results Achieved

• Approximate 1-year investment payback period (may vary depending on the facility)
• Net savings of approximately €170,000/year for a facility operating 8,500 hours annually
• Total recovery power of approximately 500 kW through integration with economizer and compressor waste heat recovery systems
• Energy gain equivalent to about 50 Sm³/h of natural gas savings

Project Scope

• Concept development and feasibility studies
• Detailed engineering and design
• Equipment supply and manufacturing
• On-site installation and system integration
• Commissioning and performance tests

The project was completed within approximately 6–8 months and all processes were executed under the EPC model.

Main Systems Used

• Heat pump system
• Custom-designed heat exchangers
• Economizer system
• Compressor waste heat recovery unit
• Automation and control systems