Cleiren Emelie, Heijkers Stijn, Ramakers Marleen, Bogaerts Annemie
Department of Chemistry, Research Group PLASMANT, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium.
ChemSusChem. 2017 Oct 23;10(20):4025-4036. doi: 10.1002/cssc.201701274. Epub 2017 Oct 2.
Dry reforming of methane (DRM) in a gliding arc plasmatron is studied for different CH fractions in the mixture. The CO and CH conversions reach their highest values of approximately 18 and 10 %, respectively, at 25 % CH in the gas mixture, corresponding to an overall energy cost of 10 kJ L (or 2.5 eV per molecule) and an energy efficiency of 66 %. CO and H are the major products, with the formation of smaller fractions of C H (x=2, 4, or 6) compounds and H O. A chemical kinetics model is used to investigate the underlying chemical processes. The calculated CO and CH conversion and the energy efficiency are in good agreement with the experimental data. The model calculations reveal that the reaction of CO (mainly at vibrationally excited levels) with H radicals is mainly responsible for the CO conversion, especially at higher CH fractions in the mixture, which explains why the CO conversion increases with increasing CH fraction. The main process responsible for CH conversion is the reaction with OH radicals. The excellent energy efficiency can be explained by the non-equilibrium character of the plasma, in which the electrons mainly activate the gas molecules, and by the important role of the vibrational kinetics of CO . The results demonstrate that a gliding arc plasmatron is very promising for DRM.
研究了在滑动电弧等离子体发生器中甲烷干重整（DRM）过程中混合物中不同甲烷分数的情况。在气体混合物中甲烷含量为25%时，一氧化碳（CO）和甲烷（CH）的转化率分别达到约18%和10%的最高值，相应的总能量成本为10 kJ L（或每分子2.5 eV），能量效率为66%。CO和H是主要产物，同时生成少量的C H（x = 2、4或6）化合物和H O。使用化学动力学模型研究潜在的化学过程。计算得到的CO和CH转化率以及能量效率与实验数据吻合良好。模型计算表明，CO（主要是处于振动激发态）与H自由基的反应是CO转化的主要原因，特别是在混合物中甲烷分数较高时，这解释了为什么CO转化率随甲烷分数增加而升高。CH转化的主要过程是与OH自由基的反应。优异的能量效率可以通过等离子体的非平衡特性来解释，其中电子主要激活气体分子，以及CO振动动力学的重要作用。结果表明，滑动电弧等离子体发生器在DRM方面非常有前景。
