Hydroxyapatite Formation during Hydrothermal Liquefaction of Algae: Synthesis and Catalytic Implications

藻类水热液化过程中羟基磷灰石的形成：合成和催化意义

基本信息

批准号：
1438652
负责人：
Susan Stagg-Williams
金额：
$ 40.97万
依托单位：
University of Kansas Center for Research Inc
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2018-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1438652&HistoricalAwards=false
关键词：
Hydroxyapatite Formation during Hydrothermal Liquefaction

项目摘要

Abstract Title: Understanding the role of calcium phosphate in improving oil properties during thermochemical conversion of wastewater-fed algae to biocrude Algae have long been investigated as a potential feedstock for renewable, affordable, and reduced carbon-footprint fuels. Hydrothermal liquefaction (HTL) is a process to convert wet algae to a carbon-rich biocrude. HTL processing of algae grown in municipal wastewater has been shown to produce a biocrude with properties similar to conventional petroleum crude. Furthermore, the HTL of wastewater-fed algae results in the production of a solid biochar product, which has hitherto been considered a waste product. However, evidence shows that wastewater-derived biochar contains a form of calcium phosphate, which may act as a catalyst to improve biocrude composition and stability. An award is made to Professors Susan Stagg-Williams and Belinda Sturm of the University of Kansas to understand the fundamental relationships between growth conditions, the formation of biochar during the HTL reaction, the formation of calcium phosphate crystals, and the ultimate impact on biocrude yield and properties. This knowledge is necessary for the ultimate commercialization of algal technology for renewable fuels and chemicals. Various educational programs are planned by the investigators which will increase public awareness and engagement with sustainable energy production. Hydrothermal liquefaction has emerged as a promising whole cell conversion technology utilizing subcritical water to convert algal biomass to a carbon-rich biocrude. Preliminary work at the University of Kansas has demonstrated that HTL of wastewater-cultivated algae leads to high biocrude yields, low biocrude O/C ratios, low levels of high boiling point compounds in the biocrude, and high production of biochar. Characterization studies have shown that the biochar produced is a calcium-deficient substituted hydroxyapatite (HAp) form of calcium phosphate. HAp has been shown to have acid-base properties and be catalytically active for the dehydration and dehydrogenation reactions. In this study, the liquefaction of algae and model compounds will be investigated to determine: 1) the impact of algal growth conditions (Ca, N, P) on the crystallization of HAp in the HTL reactor and the resultant impact on biocrude composition, 2) the impact of the HAp crystallite formation on the macromolecule monomers formed during the liquefaction reaction, and 3) the ability of HAp synthesized during liquefaction to catalytically alter the biocrude composition through dehydration and dehydrogenation reactions. Coupling controlled HAp crystal growth with the production of biocrude is novel. Generating an understanding of the relationship between growth conditions, the formation of HAp, and the ultimate impact on biocrude yield and properties has significant merit for the ultimate commercialization of algal HTL technology. Another aspect of this project supporting the recommendation for award is the environmental focus. Increasing the fundamental knowledge about the application of algal treatment systems for phosphorus removal and recovery from municipal and agricultural wastewater should yield positive environmental and economic impacts. Utilizing algal treatment systems as a low-cost alternative to nutrient removal, while generating biocrude and high-value catalysts and biomaterials, has the potential to turn a historically regulatory operation (wastewater treatment) into a revenue-generating operation.

摘要标题：了解磷酸钙在废水喂养的藻类热化学转化为生物原油过程中改善油性能的作用藻类长期以来一直被研究作为可再生、负担得起和减少碳足迹燃料的潜在原料。水热液化（HTL）是将湿藻类转化为富含碳的生物原油的过程。对城市废水中生长的藻类进行 HTL 处理已被证明可以生产出具有与传统石油原油类似特性的生物原油。此外，废水喂养的藻类的 HTL 会产生固体生物炭产品，该产品迄今为止被认为是废物。然而，有证据表明，废水衍生的生物炭含有某种形式的磷酸钙，它可以作为改善生物原油成分和稳定性的催化剂。堪萨斯大学的 Susan Stagg-Williams 和 Belinda Sturm 教授获奖，以了解生长条件、HTL 反应期间生物炭的形成、磷酸钙晶体的形成以及对生物原油产量的最终影响之间的基本关系和属性。这些知识对于可再生燃料和化学品的藻类技术的最终商业化是必要的。研究人员计划了各种教育计划，以提高公众对可持续能源生产的认识和参与。水热液化已成为一种有前途的全细胞转化技术，利用亚临界水将藻类生物质转化为富含碳的生物原油。堪萨斯大学的初步工作表明，废水培养藻类的 HTL 可以提高生物原油产量、降低生物原油 O/C 比、降低生物原油中高沸点化合物的含量以及提高生物炭产量。表征研究表明，生产的生物炭是一种缺钙的取代羟基磷灰石 (HAp) 形式的磷酸钙。 HAp 已被证明具有酸碱特性，并且对脱水和脱氢反应具有催化活性。在本研究中，将研究藻类和模型化合物的液化以确定：1) 藻类生长条件（Ca、N、P）对 HTL 反应器中 HAp 结晶的影响以及由此产生的对生物原油成分的影响，2 ) HAp 微晶形成对液化反应过程中形成的大分子单体的影响，以及 3) 液化过程中合成的 HAp 催化改变生物原油组成的能力通过脱水和脱氢反应。将受控 HAp 晶体生长与生物原油生产耦合起来是新颖的。了解生长条件、HAp 的形成以及对生物原油产量和特性的最终影响之间的关系对于藻类 HTL 技术的最终商业化具有重要意义。该项目支持获奖建议的另一个方面是对环境的关注。增加关于应用藻类处理系统去除城市和农业废水中的磷和回收的基础知识应该会产生积极的环境和经济影响。利用藻类处理系统作为营养物去除的低成本替代方案，同时产生生物原油和高价值催化剂和生物材料，有可能将历史上的监管业务（废水处理）转变为创收业务。