Increasing Sugar Yield in Biofuel Manufacturing through Control of Cellulosic Biomass Particle Size

当今的经济和社会高度依赖于液体燃料的运输。目前，美国使用的液体运输燃料中有90%以上是石油基燃料。当务之急是开发国内生产和环境友好的替代液体燃料。从纤维素生物质，如农业和林业残留物和专用能源作物中提取的生物燃料是近期至中期最佳替代品之一。纤维素生物质的尺寸减小是制造生物燃料的关键步骤。尺寸减小是能量密集型过程，并且颗粒尺寸决定了该过程中的能量消耗。该奖项支持研究，以了解纤维素生物质颗粒大小和生物燃料产量之间的关系。这项研究的成功完成将为未来的生物燃料制造技术奠定基础。这项研究将对生物燃料制造的总体成本和能源平衡产生重大影响，极大地有利于美国经济和能源安全，以及环境和社会。该项目将对工程教育产生积极影响。一个新的课程伴随着动手实验室会议将被创建，以加强本科工程课程，并让学生参与可再生能源制造项目。本研究的目的是检验三个假设，以解释纤维素生物质颗粒大小和酶解糖产率之间的关系的不一致性。在这项研究中，据推测，不一致是由使用不同的糖产量定义，粒度范围，和预处理方法。这项研究将使用目前流行的生物燃料制造技术和目前工业上使用最广泛的三种纤维素生物质，即小麦秸秆、玉米秸秆和柳枝稷。实验室和中试规模的生物燃料转化设施的实验研究将进行测试的假设。此外，纤维素生物质的结构特征、形态变化和化学组成将通过使用电子显微镜、X射线衍射分析、紫外分光光度法、高效液相色谱法、红外光谱法、西蒙染色和核磁共振技术来表征。根据实验结果，糖产量模型，结合所有重要的结构，形态和化学特征，将开发和验证。这项研究的结果将提供见解的动态降解糖化合物在水解过程中。它将推进在生物燃料制造中做出战略和运营决策所需的知识基础。

Today's economy and society are highly dependent on liquid fuels for transportation. Currently, more than 90 percent of the liquid transportation fuels used in the U.S. are petroleum-based. It is imperative to develop alternative liquid fuels that are domestically produced and environmentally benign. Biofuels, derived from cellulosic biomass such as agricultural and forestry residues and dedicated energy crops, offer one of the best near- to mid-term alternatives. Size reduction of cellulosic biomass is the key step in the manufacturing of biofuels. Size reduction is an energy intensive process, and particle size dictates the energy consumption in this process. This award supports research to understand the relationship between cellulosic biomass particle size and biofuel yield. Successful completion of this research will build a foundation for future biofuel manufacturing technologies. This research will have a significant impact on the overall cost and energy balance of biofuel manufacturing, greatly benefiting the U.S. economy and energy security, as well as the environment and society, in general. This project will have a positive impact on engineering education. A new course accompanied by hands-on lab sessions will be created to strengthen the undergraduate engineering curricula and engage students in participating projects on renewable energy manufacturing. The research objective is to test three hypotheses to explain inconsistency in the relationship between cellulosic biomass particle size and enzymatic hydrolysis sugar yield. In this research, it is hypothesized that the inconsistences are caused by the use of different sugar yield definitions, particle size ranges, and pretreatment methods. The prevailing biofuel manufacturing technology and the three most widely used cellulosic biomass currently in the industry, wheat straw, corn stover, and switchgrass, will be used in the research. Experimental investigations on both lab and pilot scale biofuel conversion facilities will be conducted to test the hypotheses. Additionally, structural features, morphological changes, and chemical compositions of cellulosic biomass will be characterized by using electron microscopy, x-ray diffraction analysis, UV spectrophotometry, high performance liquid chromatography, IR spectroscopy, Simon's stain, and nuclear magnetic resonance techniques. Based on the experimental results, a sugar yield model, incorporating all the significant structural, morphological, and chemical features, will be developed and validated. The outcome of this research will provide insights in the dynamic degradation of sugar compounds during hydrolysis. It will advance the knowledge base needed to make both strategic and operational decisions in biofuel manufacturing.