International Research Fellowship Program: Computer-Aided Molecular Design of Ionic Liquids for the Pretreatment of Cellulose

国际研究奖学金计划：用于纤维素预处理的离子液体的计算机辅助分子设计

• 批准号: 1006204
• 负责人: Derick Weis
• 金额: $ 15.09万
• 依托单位: Weis Derick C
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006204&HistoricalAwards=false
• 关键词: International; Research; Fellowship; Program; Computer

1006204WeisThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four month research fellowship by Dr. Derick Weis to work with Dr. Doug MacFarlane at Monash University in Australia and in the U.S. with Dr. Robin Rogers at the University of Alabama.Cellulose is an abundant, renewable resource available from plants that can be turned into ethanol and help replace fossil fuels. Potential feed stocks for cellulose include waste products like corn stover and sugar cane bagasse, or planting a specific crop of switch grass for harvest. Currently, the cost of cellulosic ethanol is too high for practical consideration. Environmentally friendly solvents, known as ionic liquids, have been identified for a pretreatment step in the production of cellulosic ethanol as a way to reduce the cost by making it easier for enzymes to break down biomass into fermentable sugars. Ionic liquids can be formally defined as salts that melt below 100 oC, and generally consist of a positively charged organic cation with a negatively charged anion. The solvation properties can be fine-tuned for particular applications depending on the cation/anion chosen. In recent years, ionic liquids have received a lot of focus because of the potential to develop environmentally friendly solvents. Some of the favorable characteristics include negligible vapor pressure, non-flammability, and thermal stability. The negligible vapor pressure is an important feature because of the reduced risk of respiratory problems compared to the fumes given off from traditional solvents. There is also a cost savings for industrial applications because it is possible to separate and recycle ionic liquids from other components in the process. Some important properties for developing more effective ionic liquids to be used in a pretreatment step include melting point, viscosity, and cellulose solubility. Both melting point and viscosity are essential because of process operating considerations. For example, the ionic liquid must be present in liquid form at the required temperature. Energy can also be conserved by specifically designing ionic liquids with a low melting point because a significant amount of heat will not be necessary. In a similar manner, ionic liquids with low viscosity will require less energy to pump and transport.A computer-aided molecular design (CAMD) technique is being applied to help identify potentially new ionic liquids with favorable properties for more effective cellulose pretreatment. Applying this approach is much quicker, less expensive and allows for a more comprehensive search for the most suitable candidates. Currently, there are only a limited number of ionic liquids in the literature with cellulose solubility data, and thus, few options exist for the desired application. The CAMD technique helps to select potential ionic liquids for synthesis and testing in the laboratory from the numerous combinations of cation/anion pairs available.

国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。 该计划的奖项提供了联合研究的机会，并利用独特或互补的设施，专业知识和国外的实验条件。该奖项将支持德里克Weis博士与Doug MacFarlane博士在澳大利亚莫纳什大学和美国亚拉巴马大学的Robin Rogers博士合作24个月的研究奖学金。纤维素是一种丰富的，从植物中获得的可再生资源，可以转化为乙醇，帮助取代化石燃料。 纤维素的潜在原料包括玉米秸秆和甘蔗渣等废物，或种植特定的柳枝稷作物以供收获。 目前，纤维素乙醇的成本对于实际考虑来说太高。 环境友好的溶剂，称为离子液体，已被确定用于生产纤维素乙醇的预处理步骤，作为通过使酶更容易将生物质分解为可发酵糖来降低成本的一种方式。 离子液体可以正式定义为在100 ℃以下熔化的盐，并且通常由带正电的有机阳离子和带负电的阴离子组成。 溶剂化性质可以根据所选择的阳离子/阴离子针对特定应用进行微调。 近年来，离子液体由于具有开发环境友好溶剂的潜力而受到了广泛关注。 一些有利的特性包括可忽略的蒸气压、不可燃性和热稳定性。 可忽略的蒸汽压是一个重要的特征，因为与传统溶剂释放的烟雾相比，呼吸问题的风险降低了。 对于工业应用也有成本节约，因为在该过程中可以从其他组分中分离和回收离子液体。 用于开发更有效的离子液体以用于预处理步骤的一些重要性质包括熔点、粘度和纤维素溶解度。 由于工艺操作的考虑，熔点和粘度都是必不可少的。 例如，离子液体必须在所需温度下以液体形式存在。 能量也可以通过专门设计具有低熔点的离子液体来保存，因为不需要大量的热量。 同样，低粘度离子液体的泵送和输送所需的能量也更少。计算机辅助分子设计（CAMD）技术正被应用于帮助识别具有良好性能的潜在新型离子液体，以更有效地进行纤维素预处理。 应用这种方法更快，更便宜，并且可以更全面地搜索最合适的候选人。 目前，文献中只有有限数量的离子液体具有纤维素溶解度数据，因此，对于所需的应用存在很少的选择。 CAMD技术有助于在实验室中从可用的阳离子/阴离子对的众多组合中选择用于合成和测试的潜在离子液体。