Engineering news

‘Surprising’ use of valve control system targets waste heat for electricity generation

Professional Engineering

Researchers Patrik Soltic, Andyn Omanovic and Wolfgang Schneider (Credit: Empa)
Researchers Patrik Soltic, Andyn Omanovic and Wolfgang Schneider (Credit: Empa)

The “surprising” repurposing of combustion engine technology could enable efficient use of waste heat for electricity generation, according to two Swiss research institutes.

Developed by experts at the Swiss Federal Laboratories for Materials Science and Technology (Empa), the valve control system for combustion engines with electro-hydraulically actuated valves was originally designed to reduce fuel consumption by about 20%.

That control system could now be repurposed into a new type of piston machine aimed at using waste heat from processes in the metal and cement industries, being commercialised by a spin-off from Empa and ETH Zurich. It will also use heat from the incineration of ‘lean gas’ from pyrolysis plants, which recycle plastic and other waste into fuel.

“Good ideas sometimes take surprising turns,” Empa said in an announcement. The institute awarded its former doctoral student Andyn Omanovic a fellowship for the work, which aims to provide more efficient use of waste heat than current methods using turbines.

“Turbines are particularly effective at high temperatures and for power requirements of several hundred megawatts, but our piston machine is better suited for temperature ranges of around 500-900 degrees, where the waste heat is generated irregularly, and up to the power range of several megawatts,” said Omanovic.

As the cylinder and piston form a closed space, the compression and expansion of the process take place in an “almost ideal way”, Omanovic said, enabling an “extremely high” energy yield. The waste heat is converted into mechanical power via the pistons, which is ultimately used to generate electricity.

“This process can only be implemented at all thanks to the innovative flexible control of the valves,” the Empa announcement said.

A pilot machine will be built for energy supplier IWB by the beginning of next year, designed and built specifically for waste heat generated during pyrolysis. A year later, a small series of piston machines will be delivered to a company that specialises in combustion of lean gases from landfills and biogas processing.

Commercialisation will be handled by Etavalve, a spin-off from Empa and ETH Zurich. The company was co-founded by hydraulics expert Wolfgang Schneider, who was involved in the development of the technology.

Etavalve is confident that the technology could reach the market, despite challenges such as temperature-resistant materials for the machine, and the control strategy for the thermodynamic process, which still need to be mastered.

Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.

Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.


Professional Engineering magazine

Current Issue: Issue 1, 2024

01 Cover_Final online

Read now

Professional Engineering app

  • Industry features and content
  • Engineering and Institution news
  • News and features exclusive to app users

Download our Professional Engineering app

Professional Engineering newsletter

A weekly round-up of the most popular and topical stories featured on our website, so you won't miss anything

Subscribe to Professional Engineering newsletter

Opt into your industry sector newsletter

Related articles