A reduction in catalyst's activity with time-on-stream and the formation of side products are two of the problems associated with catalytic propane dehydrogenation (PDH). Previous studies have indicated that the presence of small amounts of oxygenated additives such as water can reduce coke formation and enhance catalyst activity. The aim of the present work was to develop an appropriate kinetic model for PDH over a commercial Pt-Sn/γ -Al 2 O 3 catalyst in the presence of small amounts of water. Experimental data were obtained from a previous study where catalytic PDH was carried out in a bench scale reactor system at atmospheric pressure in the temperature range of 575-620 • C in the presence of different amounts of water. The kinetics of the main dehydrogenation reaction were described in terms of a Langmuir-Hinshelwood rate expression and the effects of water on coke deposition and catalyst sintering were considered in a catalyst deactivation model to explain the observed optimum level in the amount of added water.
This research investigates
the catalytic performance of a metal–organic
framework (MOF) with a functionalized ligand—UiO-66-NH
2
—in the oxidative desulfurization of dibenzothiophene
(DBT) in
n
-dodecane as a model fuel mixture (MFM).
The solvothermally prepared catalyst was characterized by XRD, FTIR,
1
H NMR, SEM, TGA, and MP-AES analyses. A response surface methodology
was employed for the experiment design and variable optimization using
central composite design (CCD). The effects of reaction conditions
on DBT removal efficiency, including temperature (
X
1
), oxidant agent over sulfur (O/S) mass ratio (
X
2
), and catalyst over sulfur (C/S) mass ratio
(
X
3
), were assessed. Optimal process conditions
for sulfur removal were obtained when the temperature, O/S mass ratio,
and C/S mass ratio were 72.6 °C, 1.62 mg/mg, and 12.1 mg/mg,
respectively. Under these conditions, 89.7% of DBT was removed from
the reaction mixture with a composite desirability score of 0.938.
From the results, the temperature has the most significant effect
on the oxidative desulfurization reaction. The model
F
values gave evidence that the quadratic model was well-fitted. The
reusability of the MOF catalyst in the ODS reaction was tested and
demonstrated a gradual loss of activity over four runs.
Optimization of liquefied petroleum gas (LPG) catalytic cracking is one of the most fundamental issues in light olefin production. The Response Surface Methodology (RSM) 5level3factor central composite design (CCD) was used to investigate the effects of zinc loading, water and temperature on ZSM5 performance. The results show that there is an optimum point for initial propylene and ethylene yields by changing the temperature (from 566 to 634 °C) of zinc metal loading in ZSM5 (from 0.23 to 1.57 wt%) and the water/LPG ratio (from 0.32 to 2.68), with the yields being 22.34 wt% and 28.20 wt%, respectively. The experimental data were satisfactorily fitted to quadratic models by using multiple regression analysis over the range of operating conditions. The Response Surface Methodology determined the optimal Zn loading set (0.96 wt%), water/LPG ratio (1.86) and temperature (633.6 °C) to obtain the best result for the initial yields of ethylene and propylene. For ethylene and propylene yield responses, in a quadratic model, Fvalues showed 15.08 and 54.93, respectively, which states that the models were wellfitted.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.