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

1704897/1705331乌雷纳-贝纳维德斯/瓦斯克斯生物燃料是一种可再生的碳中性能源，有可能在我们的汽车中直接取代石油，而不需要对发动机和我们的基础设施进行重大改变。下一代热解油提供了生物发酵的替代方案，但也不可避免地会有高水分，因为生物分子中的大量氧原子在热解过程中会转化为水。从水中分离碳氢化合物(如乙醇)以生产燃料需要几乎100%的去除，因为水对发动机有有害影响。同样，在水流中损失的任何燃料都会导致产品回收率较低，从而增加成本和排放，并产生必须处理的废流。因此，从水中分离乙醇或任何其他碳氢化合物是一个能量高度密集的过程，几乎没有出错的余地，这是用生物燃料取代石油所要克服的一个重大障碍。就乙醇而言，从水中提纯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的浓度变得相等，因此无法通过蒸馏完全提纯，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路线，该路线将绕过乙醇-水混合物的热共沸蒸馏，从而有可能显著降低生物衍生碳氢化合物(如乙醇)转化为生物燃料的能源消耗。在密西西比大学和代顿大学的这个合作项目中，将通过在木质素和纤维素生物聚合物中加入氧化铁来开发磁性纳米颗粒。磁性纳米颗粒将被用来与添加的蓖麻油形成颗粒稳定的乳状液，用于从混合物中提取乙醇。纳米颗粒将促进乳状液内的传质，形成两个明确定义的相，包括乙醇/蓖麻油和水。磁性氧化铁将被用来促进传质，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，价格低廉，可广泛获得。该项目将研究控制纳米粒子形状和磁性的各种方法，这些方法将影响乳液中的相界面。将探索加入纳米颗粒后乳液的稳定性，以及磁场对稳定性和相分离的影响。为了评估蓖麻油提取的最终效率，将开发一台小型分离样机。一旦用蓖麻油从水中提取乙醇，由于它们的沸点非常不同，通过蒸馏将蓖麻油从乙醇中分离出来所需的能量要少得多。如果成功，该项目将对共沸乙醇-水分离的能量强度产生重大影响，从而对生物衍生燃料的生存能力产生很大影响。由于纳米颗粒利用木质素和纤维素，这对PI的家乡密西西比州和俄亥俄州的林业行业有潜在的影响。计划开展一些外联活动，包括为中学教师创建可持续发展单元，并设计以妇女和代表性不足的少数群体为对象的夏令营。本科生和研究生都将参加这个研究项目。

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.