A research by University of Virginia found that algal biofuels are potentially less environmentally friendly than other biofuel sources such as switchgrass, canola and even corn. The research paper was published in the journal Environmental Science & Technology, which is available online at http://pubs.acs.org/doi/abs/10.1021/es902838n.
The reason that they use algae as biofuel feedstock is its many advantages. For example, they grow in water, so don’t compete with food crops on land, and tend to have higher energy yields than corn or switchgrass. A high lipid content also makes refinement for vehicle fuel applications more efficient.
The disadvantage of algal biofuels becomes obvious once the research came out, that is algae production consumes more energy, has higher greenhouse gas emissions and uses more water than other biofuel sources, such as switchgrass, canola and corn. In order to get around the potential disadvantage, some researchers proposed plans to use wastewater treatment facilities to capture essential nutrients like phosphorous and nitrogen to feed the algae. But what makes it hard is that extraction of nutrients from waste water is expensive, which may not be worth it.
The cost benefit analysis is absolutely necessary as one of the researcher said “People were investing in ethanol refineries, but then we realized that it takes a lot of petroleum to grow corn and convert it to ethanol,” Clarens said. “By the time you get done, you’ve used almost as much petroleum to make ethanol that you would have if you just put the oil straight into your car.”
– Posted by Jianchao Wang