Design of a Packed-Bed, Continuous-Flow Fermentation Process Tailored for Cellulosic Ethanol Production

专为纤维素乙醇生产而设计的填充床连续流发酵工艺

• 批准号: 1066616
• 负责人: Ronald Hedden
• 金额: $ 32.99万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1066616&HistoricalAwards=false
• 关键词: Design; Packed; Bed; Continuous; Flow

PI: Hedden, Ronald Institution: Texas Tech University Proposal Number: 1066616Title: Design of a packed-Bed Continuous-Flow Fermentation Process Tailored for Cellulosic Ethanol ProductionIntellectual MeritEthanol (EtOH) derived from lignocellulosic biomass is among the most promising alternative fuels for future automotive energy needs. However, reductions in the cost of producing cellulosic EtOH must be realized in order to make it competitive with gasoline or EtOH derived from crops such as corn and sugarcane. Process economics can be improved both by increasing the EtOH yield per unit of raw materials and by lowering capital equipment and operating costs for industrial-scale fermentations. Capital equipment and operating costs can be lowered tremendously by replacing batch fermentors with continuous-flow, immobilized cell reactors (ICR), which can be significantly smaller due to higher feedstock conversion efficiency and higher volumetric productivity. This project addresses the design of ICR processes tailored for production of cellulosic EtOH by recombinant ethanologens, using novel synthetic porous polymer scaffolds (SPPS) to partially immobilize the cells. Preliminary results show that a continuous-flow column reactor packed with an SPPS material can achieve volumetric productivity at least 14 times higher than that of a comparable batch fermentation, while the porous structure of the SPPS bed mediates problems with CO2 holdup that limit conventional gel-immobilized systems. The performance of two packed bed ICR designs will be compared: a short vertical column reactor and a stirred tank reactor with packed bed section. The PIs will also optimize characteristics of the SPPS materials (pore size, pore volume fraction, and particle size) for fermentation of cellulose-derived feedstocks. This study will systematically optimize porous polymer materials for any ICR fermentations. The investigation will initially be focused on E. coli strain LY01, due to its high specific growth rate, though this ICR designs should be equally applicable to ethanologenic strains of Saccharomyces cerevisiae or Zymomonas mobilis. This study will examine ICR systems specifically for conversion of cellulose-derived feedstocks to EtOH, using genetically modified organisms that can metabolize both hexoses and pentoses. The effects of organic inhibitors on volumetric productivity will be systematically examined with simple sugar mixtures before testing reactor performance with "real" cellulose-derived feedstocks. An analytical model of reactor performance will be developed to achieve an integrated understanding of the effects of parametric variations. Cell density will be studied using E. coli LY01 engineered to express green fluorescent protein (GFP). This study address the design of continuous-flow fermentors that are optimized to handle issues specific to cellulosic EtOH: inhibitors and particulate matter in the feed, and CO2 ventilation. Broader ImpactThis research offers a benefit to society due to its potential to provide transformative new process technology for production of fuels from renewable non-food resources. The research will generate new knowledge that can potentially benefit the developing cellulosic EtOH industry economically. The project is vital to the PI's efforts to establish educational and outreach programs in Chemical Engineering at Texas Tech, and to support integration of materials and renewable energy research with Chemical Engineering education. The PI's and co-PI's groups have historically supported outreach activities involving high school and undergraduate students, including women and members of underrepresented groups. Through the Undergraduate Research Fellowship program in the Honors College and the ConocoPhilips Bridge program at Texas Tech, undergraduate students will work with graduate students to design biotechnology experiments for the Unit Operations teaching laboratory. Two graduate students involved will complete training in Engineering Ethics through the Murdough Center for Engineering Professionalism at Texas Tech University. Students will acquire training in methods of neutron scattering and radiation safety by studying porous polymers used in fermentors. Results will be disseminated through presentations at national and international meetings and through an educational webpage regarding cellulosic EtOH, which will feature these research efforts.

PI：Hedden，Ronald Institution：Texas Tech University提案编号：1066616TITLE：针对纤维素乙醇生产的固有素乙醇（ETOH）量身定制的包装床的连续流动发酵工艺的设计，是从lignocellulosic Biomass中衍生出的，是最有希望的替代品Fuels的替代品能量。但是，必须实现产生纤维素ETOH的成本的降低，以使其与玉米和甘蔗等农作物衍生的汽油或EtoH竞争。可以通过提高每单位原材料的ETOH产量，降低资本设备和工业规模发酵的运营成本来改善工艺经济学。通过用连续流动的，固定的电池反应器（ICR）代替批处理发酵罐，可以大大降低资本设备和运营成本，由于较高的原料转换效率和较高的体积生产率，它们可能会大大降低。该项目使用新型的合成多孔聚合物支架（SPP）来探讨重组乙基学剂为生产纤维素ETOH量身定制的ICR过程的设计，以部分固定细胞。初步结果表明，带有SPPS材料的连续流柱反应器可以达到容量生产率，至少比可比的批量发酵高14倍，而SPPS床的多孔结构介导了CO2 Holdup的问题，从而限制了常规凝胶胶合体的系统。将比较两个包装床ICR设计的性能：一个短的垂直柱反应器和带包装的床单的搅拌罐反应器。 PI还将优化用于发酵纤维素衍生原料的SPPS材料（孔径，孔体积分数和粒径）的特征。这项研究将系统地优化任何ICR发酵的多孔聚合物材料。该研究最初将集中在大肠杆菌菌株LY01上，因为它的特异性生长速率很高，尽管此ICR设计应同样适用于酿酒酵母或Zymomonas mobilis的乙醇菌株。这项研究将使用可以同时代谢己糖和五糖的遗传生物来研究ICR系统，专门研究纤维素衍生的原料向EtOH的转化。有机抑制剂对体积生产率的影响将在用简单的糖混合物中进行系统检查，然后以“真实”纤维素衍生的原料测试反应堆性能。将开发反应堆性能的分析模型，以实现对参数变化影响的综合理解。将使用用于表达绿色荧光蛋白（GFP）的大肠杆菌LY01研究细胞密度。这项研究介绍了经过优化以处理纤维素ETOH特异性问题的连续流动发酵罐的设计：饲料中的抑制剂和颗粒物以及CO2通风。更广泛的影响，这项研究为社会带来了好处，因为它有潜力为可再生非食品资源提供燃料生产的变革性新工艺技术。这项研究将产生新知识，从而有可能在经济上受益于发展中的纤维素ETOH行业。该项目对于PI在德克萨斯理工学院建立化学工程中的教育和外展计划以及支持材料和可再生能源研究与化学工程教育的整合至关重要。 PI和Co-Pi的团体历史上一直支持涉及高中和本科生的外展活动，包括妇女和代表性不足的团体。通过荣誉学院的本科研究奖学金计划和德克萨斯理工学院的Conocophilips桥计划，本科生将与研究生合作，为单位操作教学实验室设计生物技术实验。参与的两名研究生将通过德克萨斯理工大学的Murdough工程专业中心完成工程伦理培训。学生将通过研究发酵罐中使用的多孔聚合物来获得中子散射和辐射安全方法的培训。结果将通过在国家和国际会议上的演讲以及有关纤维素ETOH的教育网页来传播，该网页将以这些研究为特色。

项目成果

Combinatorial Methodology for Screening Selectivity in Polymeric Pervaporation Membranes

聚合物渗透蒸发膜选择性筛选的组合方法

• DOI: 10.1021/acscombsci.5b00006
• 发表时间: 2015
• 期刊: ACS Combinatorial Science
• 作者: Godbole, Rutvik V.;Ma, Lan;Doerfert, Michael D.;Williams, Porsche;Hedden, Ronald C.
• 通讯作者: Hedden, Ronald C.