Reactive extraction for preparation of hydrogen peroxide under pressure

The preparation of hydrogen peroxide from anthrahydroquinone by reactive extraction was investigated.The integration process of oxidation of anthrahydroquinone by air and extraction of hydrogen peroxide from the organic phase with water was carried out in a sieve plate column under pressure.The conversion of anthrahydroquinone increased with increasing pressure resulting in an increase of hydrogen peroxide concentration in the aqueous phase.However,no change in extraction efficiency of hydrogen peroxide was observed.A mathematical model for gas-liquid-liquid reactive extraction was established.In themodel,the effects of pressure and gas superficial velocity on reaction were considered.With increasing gas superficial velocity,the conversion of anthrahydroquinone increased,and the fraction of hydrogen peroxide extracted reached a plateau with a maximum of 72.94%.However,both the conversion of anthrahydroquinone and the fraction of hydrogen peroxide extracted decreased with increasing organic phase superficial velocity.

Kondo resonance assisted thermoelectric transport through strongly correlated quantum dots

We theoretically studied the thermoelectric transport properties of a strongly correlated quantum dot system in the presence of the Kondo effect based on accurate numerical evaluations using the hierarchical equations of motion approach.The thermocurrent versus gate voltage shows a distinct sawtooth line-shape at high temperatures.In particular,the current changes from positive(hole charge)to negative(particle charge)in the electron number N=1 region due to the Coulomb blockade effect.However,at low temperatures,where the Kondo effect occurs,the thermocurrent’s charge polarity reverses,along with a significantly enhanced magnitude.As anticipated,the current sign can be analyzed by the occupation difference between particle and hole.Moreover,the characteristic turnover temperature can be further defined at which the influences of the Coulomb blockade and Kondo resonance are in an effective balance.Remarkably,the identified characteristic turnover temperature,as a function of the Coulomb interaction and dot-lead coupling,possessed a much higher value than the Kondo temperature.When a magnetic field is applied,a spin-polarized thermocurrent can be obtained,which could be tested in future experiments.