Solazyme, which recently announced the road-testing of blends of Soladiesel, its first algal biodiesel (earlier post), has successfully taken the test blends up to B100, according to Jonathan Wolfson, Solazyme’s CEO.
Soladiesel, the first of Solazyme’s planned algal fuel projects, is a biodiesel produced from algae that are engineered to produce an oil with an optimized fatty acid profile to enhance cold flow performance, among other properties, and are also modified to grow in the dark in industrial fermentation tanks fed with plant sugars.
The lipid composition is really important. We went out and spoke to the biodiesel companies, got their specs for lipid composition, and that’s what we’re producing. Our results are far better than soy, palm and canola.—Jonathan Wolfson
Soladiesel exceeds the requirements of both the American Society for Testing and Materials (ASTM) biodiesel standard D6751 and the European standard EN 14214. International biodiesel standards have some significantly different property specifications, highlighted by a recent study on global standards for bioethanol and biodiesel. (Earlier post.) The study suggested that one way of bridging the differences could be by blending biodiesel from different feedstocks. Soladiesel avoids that issue.
As critical as the composition of the oil molecules might be, the ability to scale production is the primary factor, according to Wolfson.
One of the things we did very early on was to talk to all the oil companies, saying we can produce these ideal oil compositions for under two bucks a gallon.
They said “Stop talking, start listening. Don’t sit here and tell me you can make the ideal molecule...show me you can do it at scale. If you can scale it, you can bring production cost down over time.”
So we threw out the R&D plans designed to make the ideal lipid molecule, and we started working on scale from a very early point, which is why we can actually scale now. We were fortunate because we hired good scientists, and we were able—even though the main focus was scale—in being able to carefully modify the composition to be what we wanted.—Jonathan Wolfson
Wolfson estimates that Solazyme has another two to three years of work until it is at production economics, defined as parity with fossil fuels.
Growing algae in fermentation tanks. The focus on scale and production economics was one of the drivers to modify algae to grow in the dark in fermentation tanks, sustained by sugar, rather than photosynthetically in the open. Growing conventional, photosynthetic algae in the open requires dealing with the variability of the environment, light limitations and contamination with microbes.
In 2001, researchers at the Department of Plant Biology of the Carnegie Institution of Washington in Palo Alto, California, and Martek Biosciences Corporation in Columbia, Maryland—which sells algae-derived products—were the first to introduce a fundamental metabolic change in a single-celled alga so that it no longer required light to grow.
The scientists found that by inserting just one gene that catalyzes glucose transport into the diatom Phaeodactylum tricornutum, the organism could thrive in the dark, getting its energy exclusively from the glucose. This marked an important first step toward large-scale, high-density, cost effective cultivation of algae using fermentation technology. The results of their study were published the journal Science.
For their experiments, the scientists individually inserted several genes responsible for glucose transport from three different organisms into P. tricornutum.
One of the genes, hup1, came from the green alga Chlorella kessleri. Three other genes, hxt1, hxt2 and hxt4, come from the yeast Saccharomyces cerevisiae, widely used in brewing, baking and ethanol production. The final gene, glut1, and the one that had shown the most promise, was involved in transporting glucose into human red blood cells to maintain metabolic processes.
The investigators introduced each of these genes into the alga and found that both the hup1 and glut1 genes allowed it to take up high levels of glucose and thrive in the dark.
Other Sola-fuels. Solazyme, which recently entered into a biodiesel feedstock development and testing agreement with Chevron Technology Ventures, a division of Chevron USA, in the shorter term is also working on developing algae optimized to produce oils for use in hydrotreatment at a refinery.
For hydrotreatment, you might want to have higher saturation [in the algal oil] and you want low saturation levels for methyl esters.—Jonathan Wolfson
Solazyme has also received funding from NIST to support a project to use algae to produce biopetroleum, which will match the composition of light sweet crude oil. (Earlier post.) The biopetroleum would be fully compatible with the infrastructure that refines, distributes retails and consumes petroleum products—not just automobile fuels but aviation fuel and chemicals as well.
As with Solazyme’s other algae-derived fuels, the biopetroleum would be produced by algae grown in fermentation tanks. The NIST funding is expected to accelerate the project by four years.
Algae are amazing. The molecules they make naturally would blow your mind. They make long chain hydrocarbons naturally—we’re taking that capability and enhancing that.
We’re not putting in a whole new pathway. If you do that, it can’t scale, you’re fighting the organism. We’re working with the evolutionary biology of the organisms, and taking tools of modern biotechnology to enhance them.—Jonathan Wolfson
Solazyme presentation to California ETAAC (Sep 2007)
L. A. Zaslavskaia, et. al. “Trophic Conversion of an Obligate Photoautotrophic Organism Through Metabolic Engineering”. Science 15 June 2001: Vol. 292. no. 5524, pp. 2073 - 2075 DOI: 10.1126/science.160015