Arc plasma reactor modification for enhancing performance of dry reforming of methane

Prebiotic Formation of Peptides Through Bubbling and Arc Plasma

The abiotic synthesis of peptides, widely regarded as one of the key chemical reactions on the prebiotic Earth, is thermodynamically constrained in solution. Herein, a simulation of the lightning phenomenon on the sea surface using bubble bursting and arc plasma under ambient conditions enables dipeptide formation of six amino acids with conversion ratios ranging from 2.6 % to 25.5 %. Additionally, we observed the formation of biologically active tripeptides and investigated the stereoselectivity of the dipeptide formation reaction. By utilizing a mixture of 20 amino acids in the reaction, 102 possible dipeptides were generated. These results establish experimental constructions to mimic achievable prebiotic conditions and provide a credible pathway for endogenous biopolymer synthesis on prebiotic Earth.

Recent advances in energy efficiency optimization methods for plasma CO2 conversion

Efforts to develop efficient methods for converting carbon dioxide (CO2) have drawn mounting interest due to incremental concerns over carbon emissions. Non-thermal plasma (NTP) technology has shown promise in this regard by producing numerous reactive substances at relatively low temperatures. However, an analysis of relevant literature reveals an underwhelming level of overall energy efficiency for this technology and an insufficient level of attention being paid to it. It is crucial to put forward more effective energy-saving schemes based on a comprehensive analysis of past research results to promote sustained development. This review highlights the latest advances in pertinent energy efficiency optimization studies and outlines state-of-the-art methods. In terms of energy efficiency optimization for plasma CO2 conversion, a comparison is made among different research results in four aspects as follows. Specifically, this study analyzes reactor structure optimization in terms of discharge characteristic, flow field, and plasma contact area; discusses pathways of heat transfer optimization to suppress the competing reaction; and explores catalyst optimization in terms of active sites, calcination temperature, and product selectivity; examines the potential of utilizing solar energy for clean energy applications. The analysis of energy efficiency data indicates an overall improvement when the aforementioned optimization measures are applied, which is essential to validate the effectiveness of each method. Finally, this paper discusses the potential difficulties and future research areas of NTP technology. Urgent further research is imperative on energy efficiency optimization methods for potential large-scale industrial applications in the future.

A Numerical Investigation of Electrically-Heated Methane Steam Reforming Over Structured Catalysts

The use of electric energy as an alternative system to provide heat of reaction enables the cut-off of CO2 emissions of several chemical processes. Among these, electrification of steam methane reforming results in a cleaner production method of hydrogen. In this work, we perform for the first time a numerical investigation of a compact steam reforming unit that exploits the electrical heating of the catalyst support. First, for such unit we consider the optimal thermodynamic conditions to perform the power to hydrogen conversion; the process should be run at atmospheric pressure and in a close temperature range. Then, among possible materials currently used for manufacturing structured supports we identify silicon carbide as the best material to run electrified steam reforming at moderate voltages and currents. The temperature and concentration profiles in idealized units are studied to understand the impact of the catalyst geometry on the process performances and open-cell foams, despite lower surface to volume show the best potential. Finally, the impact of heat losses is analyzed by considering different operative conditions and reactor geometries, showing that it is possible to obtain relatively high thermal efficiencies with the proposed methodology.