Technical Talk: A Lesson in Biofuels

This column is written by Dr. John Michaelides of the Guelph Food Technology Centre.

This column is written by Dr. John Michaelides of the Guelph Food Technology Centre.

Question: What are biofuels and how they can possibly affect the food industry?

Answer: The enormous pressure to reduce energy consumption, the high cost of fossil fuels, and the need to produce food economically and provide it at an affordable price is driving the demand for alternative fuels. The growing global population has increasing demands for more food, especially processed foods and other goods that require more energy to produce. A Western lifestyle is quickly being adopted by the rest of the world, resulting in increased greenhouse gases, global warming and catastrophic climatic changes. In order to address these issues, alternative renewable energy sources, like biofuels, are being explored.

Other renewable energy sources include wind, hydroelectric and solar. Although wind and solar are the most non-destructive and clean sources of energy they are more difficult to adopt due to the limitations of storage and transportation of such energy. However, progress is being made in these areas around the world and these clean energy sources are being implemented. Photovoltaic installations (solar energy) have been growing globally at the rate of 35 per cent a year in the past five years. While hydroelectric power generation is also clean, the process of implementing it may cause environmental concerns due to the activity of changing natural water courses and the effect that may have on fish (salmon) spawning and other animal life habitats.

So what are biofuels? The term biofuel refers to fuel that is produced from carbohydrates or vegetable oil using traditional crops as a source. Biofuels are thought to be cleaner in delivering energy than fossil fuels. They are considered renewable in the sense that the crops capture the energy from the sun and grow every season to produce the oil and the carbohydrates that can be used as feedstock for the production of the biofuels. There are various kinds of biofuels but the two most common and commercially available are bioethanol and biodiesel. Bioethanol is produced using the sugar fermentation process. Similar to the production process of potable alcohol, glucose is fermented by the yeast to produce ethanol and carbon dioxide. The first generation of bioethanol production uses mainly starch as a source of glucose from corn and wheat or sugars from cane or more recently sweet millet. Although bioethanol can be mixed with gasoline, it cannot be transported in the same manner so it presents logistical difficulties. It is also not as efficient as gasoline in terms of energy yield. A more efficient production of fuel from carbohydrates is the production of butanol which yields more energy than alcohol and it can be transported the same way as gasoline. Butanol is more efficient because it contains four carbon atoms compared to alcohol that contains two. Butanol has a greater similarity to gasoline in energy content than alcohol. Gasoline has an energy content of 114 thousand BTU per gallon where butanol has 110 thousand BTU as compared to bioethanol’s energy yield of 77 thousand BTU per gallon. The technology of butanol production, although fairly old, has not been commercially adopted yet.

Research in the use of cellulose as a feedstock for the production of alcohol is currently approaching commercialization. This second generation of bioethanol production involves the use of the cellulose from wood and other agricultural waste such as straw, sugar cane bagasse and corn stover. The reason that this method of bioethanol production is more difficult is because of the complex structure of the cellulose. Cellulose, like starch, is a complex polymer of glucose but is more difficult to break down to the fermentable glucose molecules needed for production. Cellulose is often interwoven with lignin, making it difficult to access. In spite of these difficulties, this technology is expected to be fully commercialized in the near future, and the first generation of cellulosic ethanol plants is now being built.

Biodiesel is produced from the oil from oilseeds such as soy, rapeseed, cottonseed or palm seed. Animal fat waste can be used as an oil source as well. The production process is well developed and it involves the breakdown of triglycerides, the main component of fats and oils, into glycerol and fatty acids. The fatty acids are then converted into methyl esters by the use of methanol and a catalyst. The methyl esters are used for the biodiesel while the glycerol portion of the triglyceride is the byproduct of the process and can be used to supply the glycerin market.

Biofuels, as they are produced today, represent a short-term solution to the energy crisis and unfortunately, may create additional problems. Currently, biofuels are heavily subsidized by various governments and, if these subsidies are removed, biofuels may not be viable. In addition, they are currently using valuable crop commodities that put pressure on commodity pricing, in turn increasing the cost of food manufacturing. Some researchers are suggesting that they may do more harm than good to the environment. The demand for cleaner fuel is driving tropical countries to clear more forest for growing soy (Brazil) and palm seed meant for biodiesel production and sugar cane for ethanol. This may have a devastating effect on the environment by reducing the biodiversity and decreasing the amount of CO2 that is normally absorbed by the rain forests, causing catastrophic climate change.

The baking industry is witnessing the effects of climate change on cereal production and around the world. Severe droughts in Australia and elsewhere caused wheat shortages, and increasing demand in India and China for wheat products has resulted in skyrocketing wheat prices. The price of corn is also elevated due to the increased demand to supply the ethanol industry. Demand for these commodities is not only generated from biofuel production. Biomaterials are also beginning to emerge and government strategies are encouraging the utilization of proteins and oils from crops for bioproducts. These bioproducts can be used in packaging, automobile production and other industries. This initiative is designed to increase the use of more biodegradable plastic materials from renewable resources than those from petrochemicals, which do not degrade and contribute to environmental pollution. 

We are living in a changing world with more pressure on the food industry than ever before. As an industry, we all need to do our part in adopting more sustainable practices in our day-to-day operations and to reduce our environmental carbon footprint. The carbon footprint represents a measure of the effect human activities have on the environment. This measure is based on the amount of greenhouse gas produced, measured in units of carbon dioxide. At the same time, we need to be competitive and be able to satisfy consumer’s demands. These are difficult times and that is when innovation is most likely to help.

Funding for this report was provided in part by Agriculture and Agri-Food Canada through the Agricultural Adaptation Council’s CanAdvance Program. For more information, or fee-for-service help with product or process development needs please contact the GFTC at 519-821-1246, by fax at 519-836-1281, or by e-mail at gftc@gftc.ca .