New use for old cooking oil: Making hydrogen?

Converting used cooking oil into fuel — old story, right? Not when the fuel you’re talking about is hydrogen.

Engineers at the University of Leeds say they’re developing a system that could let us extract hydrogen from waste materials like vegetable oil and the glycerol by-product of biodiesel. If successful, they say, such a system could provide environmentally friendly, high-purity hydrogen not only for large-scale power production, but also for smaller portable fuel cells.

“I can foresee a time when the processes we are investigating could help ensure that hydrogen is a mainstream fuel,” said Valerie Dupont from the School of Process, Environmental and Materials Engineering (SPEME). “We are investigating the feasibility of creating a uniquely energy-efficient method of hydrogen production which uses air rather than burners to heat the raw product. Our current research will improve the sustainability of this process and reduce its carbon emissions.”

The research is being funded with support from a grant of over £400,000 from the Engineering and Physical Sciences Research Council (EPSRC) within a consortium of 12 institutions known as SUPERGEN Sustainable Hydrogen Delivery.

While hydrogen is considered to be a potential replacement for fossil fuels, it is currently costly to extract. In addition, high levels of greenhouse gases are also often emitted during conventional methods of production.

The system being developed at Leeds — known as Unmixed and Sorption-Enhanced Steam Reforming — mixes waste products with steam to release hydrogen, and is potentially cheaper, cleaner and more energy efficient.

During the process, a hydrocarbon-based fuel from plant or waste sources is mixed with steam in a catalytic reactor, generating hydrogen and carbon dioxide along with excess water. The water is then easily condensed by cooling and the carbon dioxide is removed in-situ by a solid sorbent material.

“It’s becoming increasingly necessary for scientists devising new technologies to limit the amount of carbon dioxide they release,” Dupont said. “This project takes us one step closer to these goals — once we have technologies that enable us to produce hydrogen sustainably, the infrastructure to support its use will grow.”

She continued, “We firmly believe that these advanced steam reforming processes have great potential for helping to build the hydrogen economy. Our primary focus now is to ensure the materials we rely on — both to catalyse the desired reaction and to capture the carbon dioxide — can be used over and over again without losing their efficacy.”