用于丙烷氨氧化催化过程的微通道反应技术研究

A highly intensified catalytic process is proposed for the direct ammoxidation of propane to acrylonitrile. As one of the top chemical products produced by the chemical industry, acrylonitrile is currently produced via highly exothermic propylene ammoxidation processes. Using propane directly as the feedstock not only provides incentives to reduce the feedstock cost but also avoids the energy inefficiencies involved in the conversion of propane to propylene via dehydrogenation. The technical hurdles associated with direct propane ammoxidation arise from the more severe yet precise reaction conditions required to activate propane while minimizing non-selective oxidation of propane reactants, reaction intermediates, and products to CO and CO2, a challenge that cannot be addressed using conventional reaction technologies. We propose to use breakthrough microchannel reaction technologies that promise to improve significantly the control over reaction conditions and also to decrease substantially the energy consumption, the capital and operational costs, and the environmental burdens on the chemical industry. Single-pass space-time yields required for commercial viability will be achieved through synergistic improvements made possible by: (1) development of microchannel reactors based on rigorous kinetic and mechanistic understanding and modeling to precisely control reaction conditions; (2) exploiting the unique advantage of microchannel reactor which allows the safe operation in the explosive range; and (3) simultaneous optimization of microchannel reactors and catalyst formulations specific for use in microchannel reactors based on state-of-the-art methods and knowledge. The potential benefits of the proposed breakthrough technology include significant energy savings, substantial reductions in operational costs (feedstocks), and significant decrease in environmental burden (COx and NOx emissions) over current processes. Advances in microchannel reaction technology achieved in this program will be applicable to a wide range of chemical processes. This is well aligned with our country’s strategy to invest in crosscutting technologies with significant leveraging opportunities beyond the specific deployment discussed here.

丙烷代替丙烯氨氧化制丙烯腈具有重要的经济和环境意义，本项目拟开展适用于丙烷氨氧化反应的微通道反应基础研究。项目将针对丙烷氨氧化这个特定反应过程中丙烯腈产率较低的问题，拟从微通道反应器和催化剂集成优化同时入手，结合本征动力学和微通道反应器内传递现象及界面反应的深入研究，充分发挥微通道反应器在传热、传质等方面的优势，并利用其在易爆范围内可安全操作等特征，加深微通道反应器技术相关基础问题的理解，为开发丙烷氨氧化制丙烯腈的微通道反应器技术提供科学依据，以达到强化反应过程、提高丙烯腈产率和实现该过程的节能减排（COx和NOx）等目的。项目研究可为微通道反应器应用于其它强放热反应过程提供相应的理论基础，具有重要的科学和社会意义。

丙烷代替丙烯氨氧化制丙烯腈具有重要的经济和环境意义。本项目针对丙烷氨氧化这个特定的强放热反应过程中催化剂稳定性和催化剂床层温度的准确控制等问题，系统开展了适用于微通道反应强化反应过程的MoVTeNb氧化物催化剂的优化及微通道反应器内传递现象研究。通过本项目研究，取得如下重要进展和成果：.（1）含有M1和M2相的MoVTeNb氧化物催化剂具有优异的丙烷氨氧化制丙烯腈的转化率和选择性，但反应操作温度窗口很小（440oC~450oC）。P或者W修饰的纯M1相MoVTeNb氧化物催化剂，更适用于微通道反应器中强化条件下的使用。.（2）相比较于传统的列管式反应器，微通道反应器具有优异的传热性能。在强放热的丙烷氨氧化反应中，微通道反应器（0.5*12.7*80mm）可将催化剂床层最大温差控制到小于0.5oC之内，而相同情况下的传统的列管式反应器（Φ=4mm）的催化剂床层最大温差高达43.2oC。因此利用微通道反应器，在强化条件下可在保持低的COx选择性和催化剂稳定性的同时，达到189.9kmol/m3·h的丙烯腈产率，实现了该过程的节能减排。.项目研究成果对于丙烷氨氧化制丙烯腈的工业化具有重要的参考价值，也为微通道反应器应用于其它强放热或吸热反应过程提供相应的理论基础，具有重要的科学和社会意义。