Collaborative Research: Superparamagnetic Cellulose and Lignin Nanoparticles as Recyclable Additives to Enhance the Liquid/Liquid Extraction of Ethanol from Aqueous Solutions

点击翻译按钮获取中文摘要

1704897 / 1705331 Urena-Benavides / VasquezBiofuels are the one renewable carbon-neutral energy source that have the potential to directly displace petroleum in our automobiles without a significant change to the engine and our infrastructure. Next generation pyrolysis oils provide an alternative to biological fermentation, but will inevitably also have a high water content, as the high number of oxygen atoms in the biological molecules are converted to water during pyrolysis. Separations of hydrocarbons (such as ethanol) from water to produce a fuel requires almost 100% removal, as water has deleterious effects in the engine. Similarly, any fuels lost in the water stream lead to low product recovery, which increases costs and emissions, and creates a waste stream that must be treated. Thus, separation of ethanol, or any other hydrocarbons, from water is highly energy intensive process with little margin for error, and this is a significant hurdle to overcome to displace petroleum with biofuels. In the case of ethanol, the energy required to purify it from water is particularly high as ethanol-water mixtures form an azeotrope, meaning that the vapor and liquid concentrations become equal such that they cannot be fully purified via distillation, and require a secondary separation step that utilizes a desiccant. This project seeks to explore a novel separation route that will bypass thermal azeotropic distillation of an ethanol-water mixture, and thus has the potential to significantly decrease the energy consumption of conversion of biologically derived hydrocarbons, such as ethanol, to biofuels.In this collaborative project, magnetic nanoparticles will be developed by incorporation of iron oxide into lignin and cellulose biopolymers. The magnetic nanoparticles will be utilized to form a particle-stabilized emulsion with added castor oil, which will be used to extract the ethanol from the mixture. The nanoparticles will facilitate mass transfer within the emulsion to form two clearly defined phases, comprised of ethanol/castor oil, and water. The magnetic iron oxide will be used to facilitate mass transfer, as well as induce phase separation. Castor oil, lignin, and cellulose were chosen as they are renewable materials that are widely available at low cost. The project will study various ways to control nanoparticle shape and magnetic properties, which will affect the phase interface in the emulsion. The stability of the emulsions after incorporation of the nanoparticles will be explored, as will the effect of the magnetic field on stability and phase separation. A bench scale separation prototype will be developed to evaluate the ultimate efficiency of the castor oil extraction. Once ethanol is extracted from water by castor oil, it requires much less energy to separate castor oil from ethanol via distillation due to their highly dissimilar boiling points. If successful, the project will have significant impact on the energy intensity of azeotropic ethanol-water separations, and thus have a large impact on the viability of biologically derived fuels. As the nanoparticles utilize lignin and cellulose, there is potential impact on the forestry industry in Mississippi and Ohio, the home states of the PIs. A number of outreach activities are planned that include creation of sustainability modules for middle school teachers and engineering summer camps that target women and underrepresented minorities. Both undergraduate and graduate students will participate in the research project.