Years away from commercial production
Part 1 of 2
Part 2 of 2
With so much talk about algae oil’s prospects, it’s probably a good idea to go over some of the basic science and engineering before making any predictions. One of the ironies of biofuels and fossil fuels is that both involve the production by living plants of biomass through the process of photosynthesis. The difference, of course, is a few million years. Fossil fuels contain carbon that has been out of the carbon cycle for eons. When it combusts, the carbon is released as carbon dioxide (CO2), and thus upsets a delicate balance in our atmosphere. Climate scientists attribute this "late" release as one of the major causes of global warming.
Since biofuels and fossil fuels are almost identical in chemical make-up, biofuels such as algae oil also release CO2 into the atmosphere when they combust. The difference is that since algae oil was recently living, the CO2 also was only recently taken out of the atmosphere during photosynthesis. In essence algae oil is CO2 neutral and does not add to CO2 to the environment. Of course, it also doesn't reduce the amount of CO2.
One of the distinct advantages of algae is that almost the entire organism can use sunlight during photosynthesis to produce biomass. The amount of lipids, or oils, produced varies with each specie, with some approaching 50% lipid concentration. Algae produce lipids for energy storage in the form of triacylglycerides (TAGs). TAGs are converted into bio-diesel through a process called transesterifcation, in which the TAGS, in the presence of simple alcohols and a catalyst, produce the fuel. This bio-diesel fuel has most of physico-chemical properties of petroleum diesel fuel.
To be competitive with fossil fuels, however, biofuels need to equal or surpass the costs of producing fossil fuels. Many feel that algae is a promising prospect since it is able to produce more biomass per acre-year than any other plant under consideration. Algae also has the added advantage of not being a plant used in the production of food, such as the conversion to ethanol of corn, a feedstock for cattle. Despite this promise, there are cultivation and production challenges that must be overcome. Separating the algae from the water it grows in and pressing the oil out the dried algae are significant problems, but finding a cost-effective cultivation system is a major obstacle to scalability.
I recently heard an engineer on NPR (National Public Radio) discuss the reality of prototypes. What looks like a stripped-down, scaled-down version of the final product humming along for an audience is actually being tweaked and prodded and monitored by a team of engineers making sure (sometimes, manually) that all the systems are working. That seems to be where we are with algae oil. It can be produced, but not without putting a lot more energy in than we get out. That’s not a good plan for making money in the marketplace.
I came to this conclusion, at first, simply because of the jumble of techniques used to cultivate and process algae into biofuel. Although this could be considered a sign of strength that this marvelous little organism could be turned into the energy we all love and crave, it became clear from researching web sites and papers that we were perhaps only one or two doors down the hall from the lab where the algae oil idea was hatched. As skeptics are saying, if somebody tells you algae oil is now at competitive prices, ask where you can buy a gallon. Best estimates put the current price at about $100/gallon.
At last count, there were well over 50 start-up companies looking to turn algae into biofuel. There are about six methods being used:
1) Bioreactors -- Algae is grown in closed glass or plastic tubing, or polyethylene bags. CO2 and nutrients are fed into the system. Light can be natural (sunlight) or artificial lighting.
2) Fermentation -- Algae grows in closed tanks with no sunlight. Sugar is introduced to feed algae growth.
3) Wastewater -- Companies clean up algae-infested bodies of polluted water and turn algae into biofuel.
4) Gasification -- High temperatures are used to turn algae into biogas.
5) Green Crude -- Various methods are used to create a fuel product that can be fed directly into our current refinery system for eventual consumer use, instead of conversion to ethanol or biodiesel.
6) Open pond -- Algae is grown in shallow ponds and fed CO2 and nutrients. CO2 often comes from nearby factory smokestacks.
My problem with the sector, rather than the companies or methods, is that there seems to be no consolidation around any one or two methods, with the possible exception of bioreactors. This indicates to me that we are experimenting with methods that still are neither cost-effective or scaleable.
Enter Robert Rapier, who I ran across in my research. I could end here and just send you to his blog and web writings, but instead I will attempt to summarize his conclusions in my next post about the dimming prospects for algae fuel, as well as add my own thoughts. Remember, of course, that he is the scientist/engineer; I’m the journalist.
Disclosure: No positions