Three years ago I wasted hours upon hours of my life looking at and memorizing cell structures and names of various algae, and if you asked me then if I’d ever write a blog about them for fun, I’d of said “HELL NO!” I did not enjoy the microscope-induced headaches, memorizing useless latin names, or the countless wet mounts of cut up algae parts I had to prepare (still think it was dangerous to give out razor blades to students at the beginning of a three hour algae lab…) However, I remember how enthusiastic my awesome prof was when telling us all about algae abundance and versatility. There are so many kinds of algae, found in all corners of the earth, and there are so many things it can do! So, that’s what I’m going to highlight today – some of the many wonderful things our little photosynthetic friends are capable of.
- Algae as a biofuel
- Algae as an alternate food source
- Algae to clean oil spills
Algae as a Biofuel
Algae converts sunlight, water, and carbon dioxide into oxygen and sugars, which the algae then metabolize into lipids, or oil. Algae has an extremely high oil yield – for some micro-algal species oil content makes up about 60% of their biomass! These fast growing unicellular organisms can complete an entire growth cycle every few days, allowing them to produce up to 15,000 gallons of oil per acre per year under optimum conditions. It would be very difficult for other feedstocks such as palm or soy to produce even comparable amounts of oil, and they would need much more land. Algae growing can be done in varying climates, using non-potable water, and without converting more forests into farm fields.
So here is an organism that eats carbon dioxide, the most threatening and talked about greenhouse gas, all the while creating a lipid-packed cell that can effectively be used as an alternate fuel source. Most likely, it’s the only biofeedstock that could theoretically replace all petro-fuel use in the future. WOW, so how is this done?
Since algae can be grown basically anywhere there is water and adequate sunlight, cultivation is done in numerous ways. This is great because instead of occupying precious real estate, algae can succeed in open ponds (natural or artificial ponds and containers), closed ponds (more controlled), in a marine environment (difficult), in sewage and wastewater, in a photobioreactor, or even in a desert!
“PBRs facilitate better control of culture environment such as carbon dioxide supply, water supply, optimal temperature, efficient exposure to light, culture density, pH levels, gas supply rate, mixing regime, etc.”
After the algae is cultivated it needs to be harvested.
“Gathering algae consists of separating algae from the growing medium, drying, and processing it to obtain the desired product. Separating algae from its medium is known as harvesting. Harvesting methods depends primarily on the type of algae. The high water content of algae must be removed to enable harvesting. The most common harvesting processes are flocculation, microscreening and centrifugation. These must be energy-efficient and relatively inexpensive so selecting easy-to harvest strains is important.”
After this, the oil must be extracted from the algae and this can be done mechanically, chemically, or by a combination of the two.
Unfortunately, the more and more research I do, the more I’m realizing that this topic is “like, so two years ago” … but I don’t understand why? Everything seems to point towards algae biofuels being extremely beneficial, and it seems that all major companies had jumped onboard (Shell, BP, Exxon, Chevron, Valero all made biofuel commitments several years ago) and given the research and production the “green” light. So why has all the hype subdued? Why is Shell selling shares and exiting commitments?
$$$$$$$$$$, of course.
Apparently “biofuels are still too cost-prohibitive to go mass market.” I guess the harvesting and extracting equipment could be pretty costly, and cost for the consumer can range from 30-40 cents more per gallon of B20 blend (20% biodiesel) than standard diesel. Biodiesel has also been found to have lower fuel economy, requiring about 1.1 gallons of biodiesel for every 1 gallon of standard diesel, and has led to problems with deposits in fuel filters and breakage of rubber components.
So, unfortunately, until investors can create affordable ways to produce biodiesel consumers are not going to be able to afford it, and until that happens manufactures are not going to feel pressured to create biodiesel-specific vehicles. Fortunately, there is still a lot of research being done in all of these areas and algae as a renewable energy source is remaining a much talked about topic.
YOU can help speed up this process by creating more public awareness on the issue. Make it a topic in your dinnertime conversation! Tell the guy next to you on the bus that algae is going to save the world! Or, comment or tweet to me about.. I love talkin’ green!
Stay tuned for part 2 – algae as an alternate food source!
(Sources: http://www.oilgae.com/, http://www.fastcompany.com/1723391/shell-ditches-algae-biofuel-during-year-of-choices, http://www.scientificamerican.com/article.cfm?id=algae-biofuel-of-future, http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/biodiesel4.htm)