Maximizing waste energy recovery in brownfields

Ongoing geopolitical uncertainties, ever-changing monetary policies, regulatory action in response to climate change, societal pressures . . . the list of factors influencing changes in the ways industrial products are produced today is nothing short of tremendous.

In a new article for Processing Magazine, Warren Chung of Solex Thermal Science addresses the many obstacles that operators are facing in balancing carbon-reducing actions with profitability.

Yet he also talks about hope. Of note, Chung singles out heat integration as a, "low-risk and high-return activity that operators can use to reduce their energy input requirements."

Highlights:

• Most industrial operations possess significant heat integration potential: Hot process streams such as combustion flue gases have long been rich in energy recovery potential. Yet energy recovery from these streams has been difficult to realize due to heavy particulate loads, high acidities and extreme temperatures.

• Historically, equipment constraints have had limited heat integration success: The concept of heat integration is not new. The degree of that integration, however, has been constrained by the technical limitations of the heat exchange equipment, leaving difficult-to-handle process streams unintegrated. 

• Heat pipe heat exchangers (HPHEs) represent a reliable solution: Where other equipment continues to fail, HPHEs can handled complex heat recovery challenges where comparable equipment is inadequate.

A typical heat pipe heat exchanger arrangement for recovering waste heat from a hot combustion gas stream.

Chung offers two case studies from Econotherm that illustrate HPHEs in action:

1. Automotive parts casting manufacturing facility in Kentucky, U.S.: 530-kW air pre-heater generated $150,000/year of energy savings with a final project cost of $210,000. Payback was calculated at 16.2 months.

2. Oil and gas refinery in Illinois, U.S.: Air pre-heater replaced an existing and underperforming DEKA air preheater, resulting in 7.1 MW of recovered energy.

Conclusion:

"As modern operators seek to reduce energy consumption and emissions to improve profitability and environmental outcomes, the appropriate technology selection will be paramount," writes Chung.

"HPHE technology is a proven, reliable, safe and customizable option that enables incremental energy recovery from waste heat streams that are otherwise unexploited or under-exploited.

Read the full article.