Randy Duffy, research associate, University of Guelph’s Ridgetown Campus, sees potential for corn stover beyond bedding and feed.Photo by Janet Kanters.
If green chemistry sounds more like an oxymoron than an opportunity, be prepared for some big surprises in the not-so-distant future.Innovators within the manufacturing industry are getting back to nature and the door is open for farmers to take part. While the production of biofuels remains a popular example of green chemistry, ethanol is only the tip of the iceberg when it comes to industrial products that are being designed to include more renewable resources. As governments start to wean ethanol companies off of subsidies, Murray McLaughlin, the executive director of the Bioindustrial Innovation Centre in Sarnia, Ont., says farmers can expect to see some positive changes.“Biofuels are important, but the challenge with biofuels is slim margins,” explains McLaughlin. “On the chemical side of things, as long as oil stays above $80 per barrel, we can be competitive with any of the companies in that space and don’t need subsidies.”In the petroleum industry, it’s not uncommon for companies to direct 75 per cent of raw materials into fuel production, but these often account for only 25 per cent of annual revenue. The rest of their income is generated by higher-end products, such as succinic acid, and it has made these products major targets for green chemists. Succinic acid is a specialty chemical used to make automotive parts, coffee cup lids, disposable cutlery, construction materials, spandex, shoe soles and cosmetics. It is usually made with petroleum, but BioAmber, a company that hopes to finish building North America’s largest bio-based chemical plant in Sarnia next year, has found a way to make succinic acid using agricultural feedstocks. By using agricultural feedstocks instead of petroleum in its process, BioAmber produces a product that is not only more environmentally friendly but also, critically, costs less than petroleum-based succinic acid. In some applications, it performs even better than its petroleum-based competitors. Babette Pettersen, BioAmber’s chief commercial officer, explains how the new technology is outperforming its traditional competitors.“Succinic acid offers the highest yield on sugar among all the bio-based chemicals being developed because 25 per cent of the carbon is coming from CO2, which is much cheaper than sugar,” says Pettersen. Assuming $80 per barrel of oil and $6 per bushel of corn, BioAmber’s product pencils out at more than 40 per cent cheaper than succinic acid made from petroleum. “Our process can compete with oil as low as $35 per barrel,” Pettersen adds. The increased efficiency of the company’s process reduces the need for raw product, for example, from two kilograms of sugar to make one kilogram of ethanol to less than one kilogram of sugar to produce one kilogram of succinic acid.The new plant is projected to purchase an annual quantity of liquid dextrose from local wet mills, which is equivalent to approximately three million bushels of corn. BioAmber’s yeast, the organism that produces bio-based succinic acid, can utilize sugar from a variety of agricultural feedstocks (including cellulosic sugars that may be produced from agricultural residuals such as corn stover when this alternative becomes commercially available).Randy Duffy, research associate at the University of Guelph’s Ridgetown Campus, co-authored a recent study on the potential for a commercial scale biorefinery in Sarnia, Ont. The idea of producing sugars from agricultural residuals is attractive to companies like BioAmber, which faces public pressure against converting a potential food source into an industrial product, but also to farmers looking to convert excess field trash into cash.
“We’re at the point where some fields probably have too much corn stover and this is an opportunity for farmers if they want to get rid of their stover,” says Duffy. “Some farmers are using it for bedding and feed, but there’s a lot of potential corn stover out there not being used or demanded right now.”In fact, the report estimated that more than 500,000 dry tonnes of corn stover are available in the four-county region of Lambton, Huron, Middlesex and Chatham-Kent, and the refinery could convert half of it into cellulosic sugar annually, at a relative base price for corn stover paid to the producer of $37 to $184 per dry tonne, depending on sugar prices and sugar yields. McLaughlin says that with more and more companies look into building facilities like biorefineries, the potential benefits for farmers multiply exponentially. At the Bioindustrial Innovation Centre alone, McLaughlin says, there are three green chemistry companies already working in pilot demonstration scale operations to produce ethanol from wood waste, butanol from fermented wheat straw or corn stover, and plastic pellets with hemp, flax, wheat straw or wood fibres in them. On a full-scale basis, any one of these has significant potential to help farmers penetrate entirely new markets.Although these green products are exciting, McLaughlin strongly believes green chemistry is not going to completely replace oil and he tries to impress this on others. “There are such large volumes of these chemicals produced from oil, I don’t think we ever will get to the point where we can displace these chemicals,” he says, “but we can complement them.” He says Woodbridge’s BioFoam, a soy-based foam used in automobile interiors as seat cushions, head rests and sunshades, is an excellent example of a hybrid product that uses green technology and petroleum technology. In order for the green chemistry industry in Ontario to realize its maximum potential, he believes everyone involved needs to consider the oil industry as a potential ally rather than the enemy. “The petroleum industry already knows the chemical markets and they’ve got the distribution,” he says, “so, who better to partner with?”
What, exactly, makes some chemistry ‘greener’?Green chemistry is a relatively new concept, but rather than simply claim to be more environmentally friendly, the philosophy is defined by structured principles. Put simply, these technologies, processes, and services are required to prove safer, more energy efficient and environmentally sustainable. In 1998, Anastas and Warner defined the 12 principles of green chemistry.Prevention – Avoid creating waste rather than treating or cleaning it up after the fact.Atom economy – Synthetic methods must maximize the incorporation of all materials.Less hazardous chemical syntheses – Design synthetic methods that are least toxic to human health and the environment.Designing safer chemicals – Chemical products should be designed to be effective but with minimal toxicity.Safer solvents and auxiliaries – Avoid the unnecessary use of auxiliary substances and render harmless when used.Design for energy efficiency – Energy requirements of processes should be minimized for their environmental and economical impact. Use of renewable feedstocks – Raw materials should be renewable whenever technically and economically practical.Reduce derivatives – Use of blocking groups, protection/deprotection, temporary modification of physical/chemical processes, etc., requiring additional reagents should be minimized or avoided if possible.Catalysis – Catalytic reagents are superior to stoichiometric reagents.Design for degradation – Environmental persistence of chemical products should be minimal.Real-time analysis for pollution prevention – Real-time monitoring and control of hazardous substances must be developed.Inherently safer chemistry for accident prevention – Substances used in a chemical process should be chosen to minimize the potential for accidents.