Fast Saccharification of Lignocellulosic Biomass under Mild Conditions in the Medium of Concentrated Lithium Bromide

温和条件下浓溴化锂介质中木质纤维素生物质的快速糖化

• 批准号: 1159561
• 负责人: Xuejun Pan
• 金额: $ 29.87万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1159561&HistoricalAwards=false
• 关键词: Fast; Saccharification; Lignocellulosic; Biomass; under

Intellectual Merit:Inability of energy- and cost-effectively releasing sugars from lignocellulosic biomass is a bottleneck retarding commercial success of the technologies based on the sugar platform for producing biofuels and chemicals. In response to this challenge, this research is to establish an innovative chemical process for low-cost production of sugars from lignocellulosic biomass. Specifically, biomass like corn stover, switchgrass, hardwood, and softwood is directly hydrolyzed and fractionated in concentrated lithium bromide (LiBr, 60% w/w) in presence of small amount of acid as catalyst under mild conditions (120~140ºC, 5-60 min) without any pretreatment. Cellulose and hemicellulose of the biomass are quickly and completely hydrolyzedinto monomeric sugars (hexoses and pentoses), which can be converted into biofuels and chemicals biologically or chemically. The used LiBr can be separated from sugars by ionexchange resin, solvent extraction or crystallization and reused in the process. Lignin is separated as insoluble residue when cellulose and hemicellulose are dissolved. The lignin is expected to have a good potential for co-product development. It is anticipated that the process could significantly reduce the production cost of sugars from lignocellulose and therefore promote the sugar-based bioeconomy. Compared with existing technologies, such as acid hydrolysis or enzymatic saccharification, the LiBr-enhanced saccharification process (1) candirectly handle small size wood chips and therefore save the cost and energy for size reduction; (2) has a high sugar recovery yield because of complete saccharification and limited sugar degradation; (3) generates a concentrated sugar stream for downstream conversion; (4) is fast chemical process and does not need expensive enzymes; and (5) achieves fractionation of the biomass into sugars and lignin, facilitating utilization of biomass components.Broader Impacts:In addition to innovative research program, this proposal also emphasizes on high-quality education, development and dissemination of new knowledge, and outreach activities. The success of proposed process would provide an alternative approach for producing sugars from lignocellulosic biomass at low cost and low energy consumption. We anticipate the new process would greatly promote the bioeconomy for producing biofuels, chemicals, and materials from biomass, which could reduce greenhouse gase emission, eliminate current dependent on fossil fuels, promote rural economy, and improve energy and national security. The proposed research covers broad range of fundamental and applied aspects of science and engineering. This would provide an ideal and unique platform for teaching, training and learning. The integrated education plan will target broad range of students. In addition to regular undergraduate and graduate students, special attention will be paid to the students from high school and underrepresented groups by encouraging them participating summer projects on bioenergy. New concepts, research findings, innovative knowledge and technologies will be disseminated to academia, industry, students, government, and the general public through publishing research papers in scientific journals, presenting research outcomes at conferences, enhancing curriculum, and writing articles for non-academic magazine or media. All these will directly and/or indirectly benefit the community of research, production, learning, education, and policy-making in the area of bioenergy.

知识价值：不能从木质纤维素生物质中以能源和成本效益的方式释放糖是阻碍基于糖平台的生产生物燃料和化学品的技术取得商业成功的瓶颈。为了应对这一挑战，本研究旨在建立一种创新的化学方法，用于从木质纤维素生物质中低成本生产糖。 具体地，生物质如玉米秸秆、柳枝稷、硬木和软木在作为催化剂的少量酸的存在下在温和条件（120 〜 140ºC，5 〜 60 min）下在浓溴化锂（LiBr，60% w/w）中直接水解和分级，而无需任何预处理。生物质中的纤维素和半纤维素被快速完全水解成单糖（己糖和戊糖），这些单糖可以通过生物或化学方法转化为生物燃料和化学品。使用过的LiBr可以通过离子交换树脂、溶剂萃取或结晶从糖中分离出来，并在该过程中重复使用。当纤维素和半纤维素溶解时，木质素作为不溶性残余物分离。预计木质素具有良好的联产品开发潜力。预计该方法可以显著降低木质纤维素糖的生产成本，从而促进糖基生物经济。与现有技术如酸水解或酶促糖化相比，LiBr增强的糖化工艺（1）可以直接处理小尺寸木片，因此节省了尺寸减小的成本和能量;（2）由于完全糖化和有限的糖降解，具有高的糖回收率;（3）产生浓缩的糖流用于下游转化;（4）快速的化学过程，不需要昂贵的酶;（5）实现了生物质的分离，使其成为糖和木质素，促进了生物质成分的利用。更广泛的影响：除了创新的研究计划，该提案还强调高质量的教育，新知识的开发和传播，以及推广活动。该工艺的成功将为以低成本和低能耗从木质纤维素生物质中生产糖提供一种替代方法。我们预计，新工艺将大大促进生物经济，从生物质生产生物燃料，化学品和材料，这可以减少温室气体排放，消除目前对化石燃料的依赖，促进农村经济，提高能源和国家安全。拟议的研究涵盖广泛的科学和工程的基础和应用方面。这将为教学、培训和学习提供一个理想和独特的平台。综合教育计划将面向广泛的学生。除了普通的本科生和研究生外，还将特别关注高中生和代表性不足的群体，鼓励他们参加关于生物能源的暑期项目。新概念、研究成果、创新知识和技术将通过在科学期刊上发表研究论文、在会议上介绍研究成果、加强课程以及为非学术杂志或媒体撰写文章等方式传播给学术界、工业界、学生、政府和公众。所有这些都将直接和/或间接地使生物能源领域的研究、生产、学习、教育和决策界受益。