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

生物燃料是一种可再生的碳中和能源，有可能直接取代汽车中的石油，而无需对发动机和基础设施进行重大改变。下一代热解油为生物发酵提供了一种替代方案，但由于生物分子中的大量氧原子在热解过程中转化为水，因此不可避免地也将具有高含水量。从水中分离碳氢化合物（如乙醇）以生产燃料几乎需要100%去除，因为水对发动机有有害影响。同样，任何在水流中丢失的燃料都会导致产品回收率低，从而增加成本和排放，并产生必须处理的废物流。因此，从水中分离乙醇或任何其他碳氢化合物是高度能源密集型的过程，几乎没有误差，这是用生物燃料取代石油需要克服的一个重大障碍。以乙醇为例，从水中纯化乙醇所需的能量特别高，因为乙醇-水混合物形成共沸物，这意味着蒸汽和液体浓度变得相等，以至于它们不能通过蒸馏完全纯化，并且需要使用干燥剂的二次分离步骤。该项目旨在探索一种新的分离途径，该途径将绕过乙醇-水混合物的热共沸蒸馏，从而有可能显著降低将生物衍生碳氢化合物（如乙醇）转化为生物燃料的能耗。在密西西比大学和代顿大学之间的这个合作项目中，磁性纳米颗粒将通过将氧化铁掺入木质素和纤维素生物聚合物中来开发。磁性纳米颗粒将被用来与添加蓖麻油形成颗粒稳定的乳液，蓖麻油将被用于从混合物中提取乙醇。纳米颗粒将促进乳液内的质量传递，形成两个明确定义的相，由乙醇/蓖麻油和水组成。磁性氧化铁将用于促进传质，以及诱导相分离。之所以选择蓖麻油、木质素和纤维素，是因为它们是可再生材料，而且价格低廉。该项目将研究各种方法来控制纳米颗粒的形状和磁性，这将影响乳液中的相界面。研究了纳米粒子加入后乳液的稳定性，以及磁场对稳定性和相分离的影响。将开发一个实验规模的分离原型，以评估蓖麻油提取的最终效率。一旦用蓖麻油从水中提取乙醇，由于沸点非常不同，通过蒸馏将蓖麻油和乙醇分离需要的能量要少得多。如果成功，该项目将对共沸乙醇-水分离的能源强度产生重大影响，从而对生物衍生燃料的可行性产生重大影响。由于纳米颗粒利用木质素和纤维素，对pi的家乡密西西比州和俄亥俄州的林业产业有潜在的影响。计划开展一些外联活动，包括为中学教师创建可持续性模块，以及针对妇女和代表性不足的少数民族的工程夏令营。本科生和研究生都将参与研究项目。

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 between the Universities of Mississippi and Dayton, 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.