The lifetime deactivation patterns of a microzeolite-based 6wt%Mo/HZSM-5 in the non-oxidative dehydroaromatization of methane were measured first at 1073 K and a space velocity of 12,000 ml/g-Cat/h in continuous CH4-feeding, cyclic 5 min CH4 5 min He feed switch and cyclic 5 min CH4 5 min H2 feed switch modes.
The alternating gas liquid cyclic feed was also found useful to reduce the levels of pressure drop and bed specific deposit and exhibited the same efficiency for both short and tall beds.
Then, a set of tests under the cyclic CH4-H2 feed switch mode over different time frames, followed by the TPO measurements of the spent samples, was performed to pursue the coke accumulation behavior of the catalyst over its lifetime.
Appearance of an obvious inflection point in the course of benzene selectivity under the cyclic CH4-H2 feed switch operation mode revealed the two stages deactivation feature of the catalyst: the deactivation was first slow and then accelerated.
However, wind speed explains only approximately one third of the variation in the chick feeding anomaly, suggesting that the strikingly cyclic pattern of chick feeding rates across nests is also driven by one or more additional factors and may be evidence of complex social dynamics in the foraging behavior of this population.
Pressure drop, global holdup and pulse celerity are not affected by cyclic liquid feeding frequency, for both spherical and cylindrical extrudate particles.
Induced pulsing flow (by cyclic liquid feeding) in packed beds, operated in the trickling flow regime, is studied as a method of overall improvement of catalytic reactor operation.
Under the conditions of these tests, and for fixed mean rates G,L, the time averaged holdup and the pulse celerity are practically constant along the bed; furthermore, these quantities as well as the pressure drop do not seem to be affected by the imposed cyclic liquid feeding frequency.
Animals were housed at a constant room temperature with a 12 12 hr light/dark cyclic, and fed a standard rodent diet and water.
Heat stress, particularly in the 32HS and 34HS groups, depressed feed intake and growth, while cyclic high temperature gave rise to a less severe stress response in performance terms.
