Researchers at the US Department of Energy’s Ames Laboratory have developed bi-functional nanoparticles that perform two processing functions at once for the production of renewable diesel via the hydrogenation of oils from renewable feedstocks such as algae.
Iron nanoparticles supported on mesoporous silica nanoparticles (Fe-MSN) catalyze the hydrotreatment of fatty acids with high selectivity for hydrodeoxygenation over decarbonylation and hydrocracking. The selectivity is also affected by the pretreatment of Fe-MSN; the more reduced the catalyst the higher the yield of hydrodeoxygenation product. Fe-MSN catalyzes the conversion of crude microalgal oil into diesel-range hydrocarbons.
An Ames Lab research group, which included Igor Slowing, Kapil Kandel, Conerd Frederickson, Erica A. Smith, and Young-Jin Lee, began by using bi-functionalized mesostructured nanoparticles containing amine groups that capture free fatty acids and nickel nanoparticles that catalyze the conversion of the acids into green diesel.
Creating a bi-functional nanoparticle also improved the resulting green diesel. Using nickel for the fuel conversion alone, the process resulted in too strong of a reaction, with hydrocarbon chains that had broken down. The process, called “cracking,” created a product that held less potential as a fuel.
A very interesting thing happened when we added the component responsible for the sequestration of the fatty acids. We no longer saw the cracking of molecules. So the result is a better catalyst that produces a hydrocarbon that looks much more like diesel. It also leaves the other components of the oil behind, valuable molecules that have potential uses for the pharmaceutical and food industries.—Igor Slowing
Slowing, along with Kapil Kandel, James W. Anderegg, Nicholas C. Nelson, and Umesh Chaudhary, took the process further by using iron as the catalyst. Iron is 100 times cheaper than nickel. Using iron improved the end product even further, giving a faster conversion and also reducing the loss of CO2 in the process.
A patent application has been filed for this technology; it is available for licensing from the Iowa State University Research Foundation.
This research is supported by the US Department of Energy Office of Science.
Kapil Kandel, James W. Anderegg, Nicholas C. Nelson, Umesh Chaudhary, Igor I. Slowing (2014) “Supported iron nanoparticles for the hydrodeoxygenation of microalgal oil to green diesel,” Journal of Catalysis, Volume 314, Pages 142-148 doi: 10.1016/j.jcat.2014.04.009
Kapil Kandel, Conerd Frederickson, Erica A. Smith, Young-Jin Lee, and Igor I. Slowing (2013) “Bifunctional Adsorbent-Catalytic Nanoparticles for the Refining of Renewable Feedstocks,” ACS Catalysis 3 (12), 2750-2758 doi: 10.1021/cs4008039