Plasma-based NO_(x) synthesis has been considered as a sustainable alternative to the conventional HaberBosch process.Despite the advancements in research achieved in recent years,limited attention has been paid to th...Plasma-based NO_(x) synthesis has been considered as a sustainable alternative to the conventional HaberBosch process.Despite the advancements in research achieved in recent years,limited attention has been paid to the reversible dimerization reaction of NO_(2) to N_(2)O_(4).This reaction can significantly alter the parameters considered with the process’output,such as the concentration or volume fraction of products and the energy consumption.This work aims to investigate the significance of dimerization through theoretical analysis and experimentation.Experiments were conducted with a 2D-gliding arc reactor to evaluate the influence of dimerization in the case of plasma reactor operation.It was observed that the dimerization reaction reached equilibrium in microseconds,resulting in a maximum hypothetical NO_(2) equilibrium conversion of 48.8%.For plasma experiments,the dimerization could cause a maximum error of 14.1%in product detection,which needs to be carefully considered along with the influence of temperature variations on the measurement.展开更多
Sintering behavior of micron-sized combusted iron powder is studied in a packed bed reactor,at various temperatures under inert(nitrogen)and reducing(hydrogen)conditions.Compression tests are subsequently used to quan...Sintering behavior of micron-sized combusted iron powder is studied in a packed bed reactor,at various temperatures under inert(nitrogen)and reducing(hydrogen)conditions.Compression tests are subsequently used to quantify the degree of sintering.A sintering model,based on the formation of a solid bridge through solid state surface diffusion of iron atoms,matches the experimental results.Sintering of combusted iron occurs at temperatures≥575°C in both nitrogen and hydrogen atmospheres and increases exponentially with temperature.The observed decrease in reduction rate at high temperatures is not caused by the sintering process but by the formation of wüstite as an intermediate species,leading to the formation of a dense iron layer.Iron whiskers form at high temperatures(≥700°C)in combination with low reduction rates(≤25 vol%H2),leading to the production of sub-micron fines.展开更多
基金supported by the NOW’s Prescient project(16271)the LEAP-AGRI project AFRICA。
文摘Plasma-based NO_(x) synthesis has been considered as a sustainable alternative to the conventional HaberBosch process.Despite the advancements in research achieved in recent years,limited attention has been paid to the reversible dimerization reaction of NO_(2) to N_(2)O_(4).This reaction can significantly alter the parameters considered with the process’output,such as the concentration or volume fraction of products and the energy consumption.This work aims to investigate the significance of dimerization through theoretical analysis and experimentation.Experiments were conducted with a 2D-gliding arc reactor to evaluate the influence of dimerization in the case of plasma reactor operation.It was observed that the dimerization reaction reached equilibrium in microseconds,resulting in a maximum hypothetical NO_(2) equilibrium conversion of 48.8%.For plasma experiments,the dimerization could cause a maximum error of 14.1%in product detection,which needs to be carefully considered along with the influence of temperature variations on the measurement.
文摘Sintering behavior of micron-sized combusted iron powder is studied in a packed bed reactor,at various temperatures under inert(nitrogen)and reducing(hydrogen)conditions.Compression tests are subsequently used to quantify the degree of sintering.A sintering model,based on the formation of a solid bridge through solid state surface diffusion of iron atoms,matches the experimental results.Sintering of combusted iron occurs at temperatures≥575°C in both nitrogen and hydrogen atmospheres and increases exponentially with temperature.The observed decrease in reduction rate at high temperatures is not caused by the sintering process but by the formation of wüstite as an intermediate species,leading to the formation of a dense iron layer.Iron whiskers form at high temperatures(≥700°C)in combination with low reduction rates(≤25 vol%H2),leading to the production of sub-micron fines.
