The acid and catalytic properties of the modified MFI zeolite catalysts during the conversion of the propane–butane fraction of the associated petroleum gases into the aromatic hydrocarbons were studied. It was established that the high-silica zeolites synthesized with the new structure-forming additive of the alcohol fraction (ZKE-AF) belong to the high-silica MFI zeolites. The resulting zeolites were modified by 1–5 wt. % additives consisting of zinc oxide and sulfide. The influence of the modifying additive concentration containing zinc oxides and sulfides in an amount of 1–5% on the acid and catalytic properties of the catalysts in the conversion process of lower C3–C4 alkanes into liquid hydrocarbons was studied. The research of the acid properties of the modified zeolite catalysts by thermal desorption of ammonia showed that the total concentrations of the acidic centers of H-ZKE-AF modified by 3% and 5% ZnO increased. It was found that the highest yield of liquid hydrocarbons was on the zeolite catalysts modified by 3% and 5% ZnS, and is 60.6% and 60.5%, respectively, which is 9% more than in the initial H-ZKE-AF. The activity of the zeolite catalysts modified by zinc oxide and zinc sulfide was in correlation with their acid properties.
In this study we have investigated organophosphorous pesticides destruction by oxidizing system, which was synthesized in the polluted aqueous sulfuric acidic solutions by constant current conducting. Bulk electrolyses with lead electrode were performed in an undivided cell under amperestatic conditions to study the oxidative cleavage of commercial pesticides and pure active ingredients. The pesticides were completely destroyed following pseudofirst-order kinetics estimated according to chemical oxygen demand (COD) data and phosphate ions accumulation. The assessment of decay rate constants shows the high mineralization degree. Moreover, the general current efficiency corresponds to high impact of chemical reactions in the bulk along with electrochemical interactions and defines the reasonable treatment process time as 120 min. The decay rate constants obtained by phosphate formation are higher for glyphosate than rate constants estimated by COD. It may be explained by P-C bond breaking and phosphate ions cleavage. For further study of organophosphorous pesticides oxidation pathways in detail by described process, the conditions of electrolysis should be milder
Flowsheet of industrial refining straight-run gasoline on zeolite catalyst includes the necessary stage of fractionation of conversion products to produce commercial gasoline, gas and heavy residue. Changes in qualitative and quantitative compositions of the catalytic conversion products under catalyst deactivation require current parametrical optimization of this stage. Objective functions that take into account catalyst deactivation and the constrains depending on the requirements for product quality and equipment specifications were developed. Optimal conditions were found to differ significantly from those designed for fresh catalyst
The main aim of the study is to increase the efficiency of gasoline blending process using developed complex modeling system, it provides counting feedstock changes in the refinery, influencing detonation characteristics of trade gasoline. Final products of modeling system are precise and gasoline blending recipes are economically optimal. The relevance of the study is caused by the need to increase production volumes of trade gasoline in refineries that meet gasoline quality standards. Mathematical modeling and application of automatic computer systems are most relevant solutions for optimization of technologically difficult stages of oil production. The study considers the modeling approach to the blending process from the position of non-additivity of gasoline octane numbers. Practical results: The module of gasoline detonation characteristics developed in Borland "Delphi 7" workspace in conjunction with the module of chromatographic data analysis "Unichrom" and optimal recipes development module are combined in the universal complex system for gasoline blending process maintenance. The system allows taking into account feedstock composition changes on purpose to vary the recipes of trade gasoline blending. The developed complex system analyzes refinery conditions and recommends the feedstock supply in the process and allows getting essential economic benefit for the refineries by reducing the quality reserve of trade products
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