Non-Oxidative Propane Dehydrogenation on CrOx-ZrO2-SiO2 Catalyst Prepared by One-Pot Template-Assisted Method

Computational study of propene selectivity and yield in the dehydrogenation of propane via process simulation approach

Propene is a vital feedstock in the petrochemical industry with a vast range of applications. And there is a continuous rise in propene demand. To gain insight into how the on-purpose method could help meet the demand in the propene market, we investigated the impact of temperature (T) and pressure (P) on product distribution in terms of product yield and selectivity using the process simulation approach. Existing related studies were deployed to identify possible products that could be evaluated in the simulation. In the study, we used Gibbs minimization (with Gibb’s reactor) to predict the likely products obtained at different T and P. The impact of feed purity on product distribution was also evaluated. The study was aided by using the Aspen HYSYS process simulator, while Design Expert was used to search for the optimum conditions for higher conversion, yield, and selectivity. Results obtained for the modeling and simulation of the process show that operating the production process at a lower pressure would favor higher selectivity within the temperature range of 500–600 °C. In comparison, the one run at a higher pressure was predicted to be only promising, showing better selectivity within the range of 550–650 °C. The feed purity significantly impacts the propene amount, especially for one with sulfur impurity, leading to the formation of smaller olefins and sulfide compounds. Our study reveals the importance of reviewing feed purity before charging them into the dehydrogenation reactor to prevent poisoning, coking, and other activities, which do lead to undesired products like methane and ethylene. A catalyst can also be designed to efficiently dehydrogenate the propane to propene at a lower temperature to prevent side reactions.

Novel Complex Titanium NASICON-Type Phosphates as Acidic Catalysts for Ethanol Dehydration

The conversion of ethanol towards ethylene and diethyl ether in the presence of catalysts requires special consideration from the perspective of green chemistry. Ethanol dehydration was studied on a complex titanium phosphate MAlTiP (M0.5(1+x)AlxTi2-x(PO4)3 with M = Ni, Mn (x = 0; 0.2)) catalysts, alongside a NASICON-type structure synthesized by the sol–gel method. The initial catalysts were characterized by N2 gas sorption, SEM, XRD and spectroscopic methods (Raman and DRIFT of adsorbed CO and C6H6). The results revealed that all catalysts exhibited high activity and selectivity at 300–420 °C. The conversion of ethanol increases with the reaction temperature, reaching 67–80% at 420 °C. The MnAlTiP exhibited the highest ethylene selectivity among other catalysts, with 87% at 420 °C. The aluminum modification improved the acid properties of the catalysts, due to the appearance of Lewis acid sites (LAS) and the strength moderate Brønsted acid sites (BAS). It was shown that the activity of complex phosphates in ethanol dehydration increases with the strength of the Brønsted acid sites (BAS).

Recent Progress of Ga-Based Catalysts for Catalytic Conversion of Light Alkanes

The efficient and clean conversion of light alkanes is a research hotspot in the petrochemical industry, and the development of effective and eco-friendly non-noble metal-based catalysts is a key factor in this field. Among them, gallium is a metal component with good catalytic performance, which has been extensively used for light alkanes conversion. Herein, we critically summarize recent developments in the preparation of gallium-based catalysts and their applications in the catalytic conversion of light alkanes. First, we briefly describe the different routes of light alkane conversion. Following that, the remarkable preparation methods for gallium-based catalysts are discussed, with their state-of-the-art application in light alkane conversion. It should be noticed that the directional preparation of specific Ga species, strengthening metal-support interactions to anchor Ga species, and the application of new kinds of methods for Ga-based catalysts preparation are at the leading edge. Finally, the review provides some current limitations and future perspectives for the development of gallium-based catalysts. Recently, different kinds of Ga species were reported to be active in alkane conversion, and how to separate them with advanced in situ and ex situ characterizations is still a problem that needs to be solved. We believe that this review can provide base information for the preparation and application of Ga-based catalysts in the current stage. With these summarizations, this review can inspire new research directions of gallium-based catalysts in the catalysis conversion of light alkanes with ameliorated performances.