Algae are rich in valuable substances and can be grown easily, which makes them promising candidates for the sustainable production of raw materials. The work done by Prof. Dr. Stefan Mecking at the University of Konstanz in cooperation with plant physiologist Prof. Dr. Peter Kroth, confirms this. The two scientists have developed a method to transform algae oil into high-quality chemical raw materials which can, amongst other things, be used for the production of polymers. This opens up new possibilities for the use of algae as a raw material source beyond just a substitute for crude oil.<\/p>\n
Algae are seen as a beacon of hope in the creation of a sustainable economy and they play an important role in virtually all areas of the bioeconomy. They can be used to produce a broad range of materials and products, including energy, food supplements or as a source for new medicines. What\u2019s more, they are easy and quick to grow. \u201cLike plants, algae cover their energy requirements with light and only need water and nutrient salts for growth,\u201d explains Peter Kroth, Professor for Plant Ecophysiology at the University of Konstanz. Kroth\u2019s research focuses on algae and their biotechnological application.<\/p>\n
The advantages of algae for the bioeconomy are apparent: they do not need a large space in which to grow, they can be grown very quickly and efficiently and do not use land given over to agriculture, therefore they are not in competition with space needed for the production of food. In addition, algae oils have a much higher proportion of polyunsaturated fatty acids than conventional vegetable oils. This makes them attractive candidates for the sustainable supply of raw materials, an area that chemist Prof. Dr. Stefan Mecking from Konstanz is focused on.<\/p>\n
The idea is not just to use algae as a substitute for crude oil, but to transform them into high-quality chemical constituents for use as chemical raw materials. \u201cWe want to preserve the unique molecular structure of renewable raw materials using new catalytic methods. This helps us produce high-quality components directly without having to first make oil-like intermediaries,\u201d says Kroth, explaining the principle of the method. The doctoral students who participated in the research project managed to do just this using a new method that enabled them to transform algae oil into chemical raw materials that can then be used to produce polymers and other materials.<\/p>\n
A \u201cdream reaction\u201d leads to functional chemical components<\/p>\n
The chemists from Konstanz succeeded in transforming algae oil into high-quality chemical raw materials using a process called isomerizing alkoxycarbonylation. This is a reaction in which the unsaturated fatty acids are transformed into linear diesters in the presence of carbon monoxide, methanol and a catalyst. \u201cThis conversion is achieved through what is known as a \u2018dream reaction\u2019, during which a functional group from the centre of the algae molecule is transformed into a functional group somewhere else in the molecule,\u201d says Mecking, explaining the highly accurate procedure. A functional group from the centre of the molecule is transformed into an ester group at the end of the molecule. The new molecule then has two functional groups at its ends. \u201cSuch molecules can be easily linked together to create polymers, which is why they are attractive components for the production of plastics,\u201d explains Mecking.<\/p>\n
The researchers used unicellular Phaeodactylum tricornutum<\/em> algae for the pilot experiments. The algae oil has a high proportion of polyunsaturated fatty acids that can be genetically modified to produce larger amounts of lipid. \u201cIn principle, the synthesis can also be performed with oils from other algae. The efficiency of the reaction depends on the quantity of lipids that the algae produce as well as on the fatty acid composition,\u201d says Kroth.<\/p>\n Following their initial success, the researchers are now going on to optimize the extraction method. They have found out that ultrasonic treatment of the oil proved advantageous in terms of increasing the quantity of oil. \u201cWe are still working on the optimal extraction of algae oil,\u201d says Mecking who is also hoping to find a way to link the extraction of the oil with other catalytic reactions.<\/p>\n Mecking\u2019s research group has already produced polymers from synthetic diester molecules, which might in future be used as components for mechanically robust, but degradable materials. \u201cIn addition to using algae oil for the production of materials, it can also be used for the production of surface active substances or lubricants,\u201d says Mecking. There are many other possibilities than diesters for recovering chemical materials and Mecking still has a great deal of options to test. \u201cIn the long term, I hope to produce long-chain molecules with one or several different functional groups,\u201d says Mecking, referring to their future plans.<\/p>\n However, he believes that despite the successes so far achieved, more than one raw material source will be used to replicate crude oil. \u201cI believe that there will be several different, complementary solutions to replace crude oil,\u201d he says. And algae products could well be one such solution. They have special properties, such as the ability to produce oils with a high proportion of polyunsaturated fatty acids. But the researchers do not believe that they will be in a position to use algae to replace fossil fuels as energy providers in the foreseeable future. \u201cThe cultivation of algae and the production of algae oil is not yet energy efficient, despite the ability of algae to carry out photosynthesis. More energy is required to produce one litre of algae oil than the energy contained in a litre of the actual oil,\u201d says Kroth, who is nevertheless optimistic and believes that new methods will be found to overcome this obstacle.<\/p>\n <\/p>\n Contacts<\/strong><\/p>\n Prof. Dr. Stefan MeckingRenewable and degradable \u2013 alternatives to crude oil<\/h3>\n
\nChemical Materials Science
\nDepartment of Chemistry
\nUniversity of Konstanz
\nE-Mail: stefan.mecking@uni-konstanz.de<\/a><\/p>\n