Catalytic cracking of naphtha: The effect of Fe and Cr impregnated ZSM-5 on olefin selectivity

This study focuses on the modification of ZSM-5 in order to enhance the catalytic cracking of refinery naphtha to produce light olefins. ZSM-5 was metal modified using different loadings (0.5–5 wt%) of Fe and Cr via the impregnation method. The metal modified ZSM-5 samples are compared and the effect of metal loading on the physicochemical properties and catalytic performance is investigated. Fe and Cr modification had an effect on both the physicochemical properties of the catalysts as well as catalytic activity and selectivity. Metal loading caused a decrease in the specific surface area which decreased further with increased metal loading. Fe had a greater effect on the total acidity in particular strong acid sites when compared to Cr. The optimum Fe loading was established which promoted selectivity to olefins, in particular propylene. Fe also had a dominant effect on the P/E ratio of which a remarkable ratio of five was achieved as well as enhanced the stability of the catalyst. Cr was found to be a good promoter for selectivity to BTX products with a two-fold increase observed when compared to Fe-modified catalysts

The utility properties free from methylene chloride paint strippers

W pracy omówiono różne metody usuwania powłok lakierniczych ze szczególnym uwzględnieniem metod chemicznych z wykorzystaniem rozpuszczalników organicznych. Przedstawiono wyniki badań dotyczących opracowania preparatu do usuwania powłok lakierniczych niezawierającego chlorku metylenu, z wykorzystaniem surowców stanowiących produkty uboczne krajowego przemysłu chemicznego. Aktywność zsyntezowanych preparatów porównano z aktywnością preparatów handlowych. Badania aktywności przeprowadzono dla powłok (nowych i 15-letnich) otrzymanych z wyrobów lakierowych ftalowych, alkidowych, alkidowo-uretanowych i nitrocelulozowych. Badań dla innych typów powłok nie przeprowadzono.This article discusses various methods of paint removal. Chemical methods based on organic solvents was exactly discussed. Own achievements in the develop formulation of paint stripper without methylene chloride with use materials which are by-products of the national chemical industry were presented. Comparative tests results obtained preparations with commercial preparations were presented. The measurements were carried out for the paint coatings (new and fifteen years old) obtained from alkyd lacquer, urethane alkyd enamel and nitrocellulose lacquer. The research for others type of the coatings was not conducted

Influence of Co2 on the Catalytic Performance Of La2O3/CeO2 and CaO/CeO2 Catalysts in the Oxidative Coupling of Methane

In this work the La2O3/CeO2 (33 mol % of La) and CaO/CeO2 (33 mol % of Ca) catalysts were prepared by the impregnation method and characterized by XRD and CO2-TPD. The catalytic properties of the catalysts were tested in the OCM process at 1073 K using the methane/oxygen mixture of the mole ratio 3.7 or 2.5 additionally containing CO2 and helium balance. It was found that in the presence of both catalysts an addition of CO2 enhances the selectivity to the ethylene and ethane and it does not have Any negative infl uence on methane conversion. In the case of the CaO/CeO2 catalyst the promoting effect of CO2 was the highest. When the partial pressure of CO2 equals to 39 kPa the increase in selectivity from 36 to 41% was noted while the conversion of methane equal to 19.4-19.7 %

Dehydrogenation of propane with CO2 - a new green process for propene and synthesis gas production

Dehydrogenation of propane in the presence of CO2 was considered as an alternative to commercial dehydrogenation pathway of obtaining propene and the new sources of synthesis gas. Based on thermodynamic calculations and a catalytic tests it was shown that by controlling CO2 concentration in the feed the molar ratio of H2/CO (synthesis gas) in the products mixture can be regulated. Several different pathways of DHP-CO2 process integration with commercialized chemical processes utilized synthesis gas were proposed

Zero waste, single step methods of fabrication of reduced graphene oxide decorated with gold nanoparticles

This paper reports a novel approach to the use of carbon, in the form of reduced graphene oxide, as a reducing agent for Au(III) chloride complex ions. This approach allows fabrication of a composite material Au@GOr in a single-step process. The reduction of Au(III) complex ions was performed using high pressure, 50 bar, and high temperature, 250°C, reactor. The average diameter of obtained gold nanoparticles was below 3 nm. The advantage of the reduced graphene oxide as the reducing agent is its high surface area. This accelerates the reaction rate significantly. The greenness and sustainability of the process are assessed by green chemistry metrics and circularity indicators recently applied for the first time to a nanomaterial synthesis. As a key green metrics, atom economy (AE) measures the degree of the incorporation of reactant atoms into the final product and in the case of the research presented scoring 99%