Hydrodynamic and turbulent structures in the trayed bubble column with 1.2 m inner diameter have been characterized from liquid-phase velocity-time series data obtained by the hot-film anemometer. Wavelet transform an...Hydrodynamic and turbulent structures in the trayed bubble column with 1.2 m inner diameter have been characterized from liquid-phase velocity-time series data obtained by the hot-film anemometer. Wavelet transform analysis was used for denoising the measured data and also for evaluating quantifiers of turbulence, viz., local intermittency measure, intermittency index and flatness factor. These quantifiers help in detecting the passage of bubbles and reveal the hidden structures and patterns in data. Also, the wavelet scalewise analysis of the turbulence at various locations in the column and under different operating conditions could be used to build a direct relationship between the local gas holdup and flatness factor. The methodology is therefore suitable for online evaluation of the trayed bubble column performance and shows promise for developing strategies for improving process performance.展开更多
Methane is the main constituent of natural gas, coal-bed gas, landfill gas and methane hydrate resources. These resources may be used more efficiently as clean fuels or as chemical feedstocks if methane can be effecti...Methane is the main constituent of natural gas, coal-bed gas, landfill gas and methane hydrate resources. These resources may be used more efficiently as clean fuels or as chemical feedstocks if methane can be effectively transformed into liquid fuels or chemicals. However, methane only possesses C-H bonds and is a very stable organic molecule hard to functionalize. The C-H activation, particularly the selective functionalization of C-H bonds in saturated hydrocarbons, remains a difficult challenge in chemistry. The present technology for chemical utilization of methane involves the steam reforming of methane to synthesis gas and the subsequent transformation of synthesis gas to methanol or hydrocarbon fuels via methanol synthesis or Fischer-Tropsch synthesis. However, the steam reforming of methane is a high-cost process. The development of more efficient and economical processes for methane transformation is a dream of all chemists and chemical engineers. I think that this is also one of the most important themes of the Journal of Natural Gas Chemistry.展开更多
文摘Hydrodynamic and turbulent structures in the trayed bubble column with 1.2 m inner diameter have been characterized from liquid-phase velocity-time series data obtained by the hot-film anemometer. Wavelet transform analysis was used for denoising the measured data and also for evaluating quantifiers of turbulence, viz., local intermittency measure, intermittency index and flatness factor. These quantifiers help in detecting the passage of bubbles and reveal the hidden structures and patterns in data. Also, the wavelet scalewise analysis of the turbulence at various locations in the column and under different operating conditions could be used to build a direct relationship between the local gas holdup and flatness factor. The methodology is therefore suitable for online evaluation of the trayed bubble column performance and shows promise for developing strategies for improving process performance.
文摘Methane is the main constituent of natural gas, coal-bed gas, landfill gas and methane hydrate resources. These resources may be used more efficiently as clean fuels or as chemical feedstocks if methane can be effectively transformed into liquid fuels or chemicals. However, methane only possesses C-H bonds and is a very stable organic molecule hard to functionalize. The C-H activation, particularly the selective functionalization of C-H bonds in saturated hydrocarbons, remains a difficult challenge in chemistry. The present technology for chemical utilization of methane involves the steam reforming of methane to synthesis gas and the subsequent transformation of synthesis gas to methanol or hydrocarbon fuels via methanol synthesis or Fischer-Tropsch synthesis. However, the steam reforming of methane is a high-cost process. The development of more efficient and economical processes for methane transformation is a dream of all chemists and chemical engineers. I think that this is also one of the most important themes of the Journal of Natural Gas Chemistry.
