Adam Mohamed, Anbari Hossein, Hart Abarasi, Wood Joseph, Robinson John P, Rigby Sean P
Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK.
Chem Eng J. 2021 Jun 1;413:127420. doi: 10.1016/j.cej.2020.127420. Epub 2020 Oct 22.
In-situ combustion alone may not provide sufficient heating for downhole, catalytic upgrading of heavy oil in the Toe-to-Heel Air Injection (THAI) process. In this study, a new microwave heating technique has been proposed as a strategy to provide the requisite heating. Microwave technology is alone able to provide rapid heating which can be targeted at the catalyst packing and/or the incoming oil in its immediate vicinity. It was demonstrated, contrary to previous assertions, that heavy oil can be heated directly with microwaves to 425 °C, which is the temperature needed for successful catalytic upgrading, without the need for an additional microwave susceptor. Upgrading of >3.2° API points, a reduction in viscosity to less than 100 cP, and >12% reduction in sulfur content was achieved using commercially available hydrodesulfurization (HDS) catalyst. The HDS catalyst induced dehydrogenation, with nearly 20% hydrogen detected in the gas product. Hence, in THAI field settings, part of the oil-in-place could be sacrificed for dehydrogenation, with the produced hydrogen directed to aid hydrodesulfurization and improve upgrading. Further, this could provide a route for downhole hydrogen production, which can contribute to the efforts towards the hydrogen economy. A single, unified model of evolving catalyst structure was developed. The model incorporated the unusual gas sorption data, computerized x-ray tomography and electron microprobe characterization, as well as the reaction behavior. The proposed model also highlighted the significant impact of the particular catalyst fabrication process on the catalytic activity.
仅靠就地燃烧可能无法为从趾端到跟端注空气（THAI）工艺中井下重油的催化升级提供足够的热量。在本研究中，已提出一种新的微波加热技术作为提供所需热量的策略。微波技术本身能够提供快速加热，可针对催化剂填料和/或其紧邻区域内进入的油。与先前的断言相反，已证明重油可直接用微波加热至425℃，这是成功进行催化升级所需的温度，而无需额外的微波感受器。使用市售的加氢脱硫（HDS）催化剂实现了API度提高>3.2个点、粘度降低至小于100厘泊以及硫含量降低>12%。HDS催化剂引发脱氢反应，在气体产物中检测到近20%的氢气。因此，在THAI现场环境中，部分原地油可用于脱氢，产生的氢气用于辅助加氢脱硫并改善升级效果。此外，这可为井下制氢提供一条途径，有助于推动氢经济的发展。开发了一个单一的、统一的催化剂结构演变模型。该模型纳入了异常的气体吸附数据、计算机化X射线断层扫描和电子微探针表征以及反应行为。所提出的模型还突出了特定催化剂制备工艺对催化活性的重大影响。
