Biofuels: a clean energy alternative
Heating your home or powering your car using fuel made from scraps of wood and food waste is not necessarily a farfetched idea.
Biofuels are made from material as diverse as algae and cooking greases and are, therefore, readily available. But, there are challenges when it comes to using them to power our engines and systems.
Some of these challenges include compatibility of biofuels with petroleum and how best to optimize biofuels without making major changes to engines and boilers. Many remote communities don't have the dollars or infrastructure when it comes to implementing most alternative energy sources. Biofuels can be sourced from food crops, but using land for fuel versus food has serious environmental and societal implications.
The ideal source of biofuel is waste. Commercial, municipal and industrial waste is expensive to dispose of both from an economic and environmental perspective.
Enter Dr. Kelly Hawboldt, a professor in the Faculty of Engineering and Applied Science at Memorial. She is overcoming these challenges by developing green processing biofuel extraction/production methods derived from waste biomass.
Dr. Hawboldt says biofuels derived from waste biomass have the advantage of recovering a valuable byproduct from waste, which decreases its volume and toxicity.
“We produce municipal, commercial and industrial waste that typically goes to landfills or, in the past, to incineration,” she said. “Incineration of waste has really detrimental effects on air quality and landfills are expensive to operate and space for these landfills is rapidly decreasing. In most waste streams there are valuable products – the most easily accessible in terms of extracting these products from the waste sustainably – is biofuel.”
Dr. Hawboldt’s research is focused on regions where remoteness, infrastructure, distance to market, low volumes and highly diverse feedstock have limited the production of biofuels. She also focuses on two integrated areas of research – fish processing plant waste and forestry residues.
“Waste generated from fish processing plants makes up about half the total weight of harvested fish, and the costs associated with collecting, storing and transporting the waste to disposal sites are significant,” said Dr. Hawboldt. “Extracting the oil from the waste – which accounts for between 2-35 per cent of the weight of the waste – reduces its volume and recovers a product that can be used on site as a heating fuel, which, in turn, decreases fuel transportation costs. In addition, the material left after the oil is extracted is still rich in other products such as proteins and enzymes that could be used in industrial chemical synthesis such as antifreeze.”
As fish plants in Newfoundland and Labrador and around the world are typically remotely located, reducing cost is of high importance.
“The forestry industry mirrors these same challenges,” said Dr. Hawboldt. “Large stockpiles of forestry residues, such as bark, sawdust and chips, are often in remote areas and costly to store and transport. In this case the residues can be thermal or biochemically converted to fuels.”
Dr. Hawboldt, with Dr. Bob Helleur in the Faculty of Science’s Department of Chemistry, thermally convert the residues to bio-gas, bio-oil and bio-char. They blend bio-oil, produced from heating forestry wastes to high temperatures, with petroleum to use as heating fuel or to upgrade the bio-oil to transport fuel. Another possibility they are investigating is using bio-char as an adsorbent, which could be used to treat offshore oil and gas and mining waste streams.
“This represents a truly sustainable approach to waste management where waste treats waste,” said Dr. Hawboldt. “We are also developing green methods to produce bio-ethanol from forestry residues, with Dr. Yan Zhang in the Department of Process Engineering. This is challenging due to the degraded nature of the residues – aging due to stockpiling.”
Dr. Hawboldt and her team are also studying the use of the bio-ethanol as an additive to the bio-oil. The addition of bio-ethanol makes the bio-oil behave more like petroleum based oil when it is burned, and therefore can be used as a replacement for low grade heating fuel, says Dr. Hawboldt. It can also be used for higher end applications such as diesel engines if its ability to be blended with petroleum-based fuels is improved. They are integrating these research streams by investigating the blending of bio-oil waste fish oil and petroleum fuels to produce a better quality fuel with good burning ability and a lower ecological footprint, ultimately creating less greenhouse gas emissions.
“The overall objective is to produce green fuels that can be used alone or as a blend in our existing petroleum based infrastructure.”