CAREER: Theory-guided design of a novel chemical looping process for methane coupling using hydrogen storage materials

职业：利用储氢材料进行甲烷耦合的新型化学循环工艺的理论指导设计

• 批准号: 1454384
• 负责人: Lars Grabow
• 金额: $ 50万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1454384&HistoricalAwards=false
• 关键词: CAREER; Theory; guided; design; novel

1454384 - GrabowAn economically viable process to transform abundant natural gas, primarily composed of methane (CH4), to higher value products (e.g. ethane or ethylene) could revolutionize the chemical industry. The prevailing challenge in all processes using CH4 feedstock is activating the strong C-H bond, which is typically done in the presence of an oxidizing agent and requires high temperatures for activation coincidentally leading to unselective reaction pathways. The primary goal of this project is to develop a new chemical looping process for selective CH4 coupling in the absence of oxygen using hydrogen storage materials. First principles calculations will guide the selection of promising hydrogen storage materials and subsequent reaction/diffusion modeling will further narrow down the group of candidate materials. Laboratory scale experimental testing is used to verify the model predictions and to optimize the operating conditions. Recent technological developments in hydraulic fracturing (fracking) to produce shale gas provide a huge incentive to develop commercially viable methane conversion processes to benefit the U.S. economy. Utilization of large shale and tight gas reservoirs in the U.S. and many other parts of the world have led to an increased interest in its main component, methane (CH4). As of 2011 the proven natural gas reserves total 208.4 trillion cubic meters worldwide, of which 7.72 trillion cubic meters are located in the U.S. Natural gas is also a significant byproduct during oil production and an estimated 150 billion cubic meters are being flared annually.Traditional uses of methane include electricity generation (combustion) and conversion to syngas, a mixture of CO and H2, using steam reforming over Ni-based catalysts.However, the potential for methane as a feedstock for the production of liquid hydrocarbons and useful chemicals has not yet been fully realized and an economically viable methane to higher value chemicals upgrade process could revolutionize the energy sector and chemical industry. The pervasive challenge of using CH4 as feedstock is activating the very strong C-H bond (435 kJ/mol). Currently implemented processes utilizing CH4 require high temperatures and the presence of oxygen-containing species (e.g. O2, H2O, CO2). These processes work well for the generation of syngas, which can subsequently be converted to higher hydrocarbons in a Fischer-Tropsch synthesis reactor. However, the direct conversion of CH4 to C2+ species remains one of the grand challenges in the chemical industry. Oxidative coupling of methane (OCM), could potentially address this challenge, but decades of intensive research have not been able to solve the issue of carbon selectivity. The competing combustion reaction consumes a large fraction of the CH4 feedstock and the high reactivity of the CH3 intermediates in the presence of O2 presents an insurmountable obstacle. In this research project a new process for methane coupling is proposed, which uses chemical looping and hydrogen storage materials to separate the carbon and oxygen atoms in order to avoid the formation of undesired carbon monoxide (CO) or carbon dioxide (CO2). The proposed research activities will be integrated with broad-reaching educational efforts at the K-12, undergraduate, graduate and professional level to broaden the participation of minority students and increase the retention of at-risk students. Partnerships with Marlo Diosomito and two economically disadvantaged Title-1 high schools in the Cypress Fairbanks ISD that the PI supervises will be leveraged to generate more interest in STEM disciplines and increase the representation of students from low-income families. UH is a designated Hispanic-Serving Institution and has the most ethnically balanced student body of all major research institutions in the U.S.

1454384 -Grabow一种经济上可行的将主要由甲烷（CH 4）组成的丰富天然气转化为更高价值产品（如乙烷或乙烯）的工艺可能会彻底改变化学工业。在使用CH 4原料的所有工艺中，普遍存在的挑战是活化强C-H键，这通常在氧化剂存在下进行，并且需要高温活化，同时导致非选择性反应途径。该项目的主要目标是开发一种新的化学循环过程，用于在没有氧气的情况下使用储氢材料进行选择性CH 4偶联。第一性原理计算将指导有前途的储氢材料的选择，随后的反应/扩散模型将进一步缩小候选材料的范围。实验室规模的实验测试用于验证模型预测和优化操作条件。最近水力压裂（压裂）生产页岩气的技术发展为开发商业上可行的甲烷转化工艺以造福美国经济提供了巨大的动力。 在美国和世界许多其他地区，大型页岩气和致密气储层的利用导致对其主要成分甲烷（CH 4）的兴趣增加。截至2011年，全球已探明的天然气储量总计208.4万亿立方米，其中7.72万亿立方米位于美国。天然气也是石油生产过程中的重要副产品，估计每年有1500亿立方米被燃烧。甲烷的传统用途包括发电（燃烧）和转化成合成气，CO和H2的混合物，使用Ni基催化剂上的蒸汽重整。甲烷作为生产液态烃和有用化学品的原料的潜力尚未完全实现，可以彻底改变能源和化学工业。使用CH 4作为原料的普遍挑战是活化非常强的C-H键（435 kJ/mol）。目前实施的利用CH 4的方法需要高温和存在含氧物质（例如O2、H2O、CO2）。这些方法对于合成气的产生效果良好，合成气随后可以在费-托合成反应器中转化为高级烃。然而，CH 4直接转化为C2+物质仍然是化学工业中的重大挑战之一。甲烷氧化偶联（OCM）可能解决这一挑战，但数十年的深入研究仍未能解决碳选择性问题。竞争燃烧反应消耗了大部分的CH 4原料，并且在O2存在下CH 3中间体的高反应性呈现出不可逾越的障碍。在本研究项目中，提出了一种新的甲烷偶联工艺，该工艺使用化学链和储氢材料来分离碳原子和氧原子，以避免形成不需要的一氧化碳（CO）或二氧化碳（CO2）。拟议的研究活动将与K-12、本科生、研究生和专业一级的广泛教育努力相结合，以扩大少数民族学生的参与，并增加有风险学生的保留率。与Marlo Diosomito和两所经济上处于劣势的Cypress费尔班克斯ISD中的Title-1高中的合作伙伴关系将被利用，以产生对STEM学科的更多兴趣，并增加来自低收入家庭的学生的代表性。UH是一个指定的西班牙裔服务机构，拥有美国所有主要研究机构中种族最平衡的学生群体。