Waste not, want not

Dr. George Nakhla

Western Engineering News | March 31, 2015

By Jason Teakle

Using microorganisms to manufacture important gases and fuels for industrial applications is keeping researchers busy at Western Engineering.

George Nakhla, a professor in the Department of Civil and Environmental Engineering, is currently working on two NSERC/CRDs on behalf of Chatham-based company, Greenfield Ethanol. The research aims to derive hydrogen, methane, ethanol and other valuable industrial products from organic wastes, using innovative biological processes and leading-edge equipment.

And there is much to be gained.

“Hydrogen is a valuable industrial gas, which often sells for $4.00 per kilogram,” Nakhla explained. “We are trying to optimize hydrogen production by developing and using a consortium of pure microbial cultures, including different strains of clostridium.”

Nakhla has patented a two-stage biological process called an integrated bioreactor clarifier system to recover energy from a variety of organic wastes using bio-degradation.

As organic waste enters the integrated bioreactor clarifier system, chemical reactions occur as the waste passes through the stages of the process, from which hydrogen and methane can be harvested.

The work will help cut the environmental impact of a variety of wastes while providing an eco-friendly way to manufacture gases and fuels required in a wide range of industrial uses, he said, adding that the innovation really is in the process.

“The process requires carbohydrates and thin stillage fermentation waste,” he said. “It reduces pollution because these wastes have to be landfilled, processed or treated.”

Greenfield Ethanol has developed an extruder that is able to separate C5 and C6 sugars, Nakhla said.

“If you can ferment C5 sugar, you don’t have to use corn to produce ethanol,” Nakhla said. “You can use woodchips, forestry products and waste from pulp and paper mills and ferment this to produce ethanol.”

Though the company’s extruder has been developed, Nakhla’s work seeks to refine the details and improve the device’s efficiency.

“(Greenfield Ethanol) has a pilot of this extruder and we’re working with them on optimizing the separation of various types of carbohydrates, which turn to sugars,” Nakhla explained. “During the process, we want to ensure that these carbs can be converted to ethanol, hydrogen and methane with minimal residues.”

The project, co-funded by NSERC/CRD and Greenfield Ethanol with $1.3 million over three years, will eventually allow the company to sell its processing technology and produce in-demand industrial products.

“This will allow them to market this technology itself, but also, they can take all these wastes and convert them into ethanol, hydrogen, methane and other valuable products.”