Intensification and forecasting of low-pour-point diesel fuel production via modelling reactor and stabilizer column at industrial unit

In this work forecast calculation of stabilizer column in the technology of low-pour- point diesel fuel production was modelled. The results of forecast calculation were proved by full-scale experiment at diesel fuel catalytic dewaxing unit. The forecast calculation and full- scale experiment made it possible to determine the ways of mass transfer intensification, as well as to increase the degree of hydrogen sulphide removal in the column, and thereby to decrease corrosiveness of the product stream. It was found out that maintenance of the reflux rate in the range of 80-90 m3/h and injection of additional vapourizing streams, such as stable naphtha from distillation unit (in the volume of 10-22 m{3}/h) and hydrogen-containing gas (in the volume of 100-300 m{3}/h), ensure complete elimination of corrosive hydrogen sulphide from the product stream. Reduction of stream corrosive activity due to suggested solutions extends service life of equipment and pipelines at industrial catalytic dewaxing unit

Intensification and forecasting of low-pour-point diesel fuel production via modelling reactor and stabilizer column at industrial unit

In this work forecast calculation of stabilizer column in the technology of low-pour- point diesel fuel production was modelled. The results of forecast calculation were proved by full-scale experiment at diesel fuel catalytic dewaxing unit. The forecast calculation and full- scale experiment made it possible to determine the ways of mass transfer intensification, as well as to increase the degree of hydrogen sulphide removal in the column, and thereby to decrease corrosiveness of the product stream. It was found out that maintenance of the reflux rate in the range of 80-90 m3/h and injection of additional vapourizing streams, such as stable naphtha from distillation unit (in the volume of 10-22 m{3}/h) and hydrogen-containing gas (in the volume of 100-300 m{3}/h), ensure complete elimination of corrosive hydrogen sulphide from the product stream. Reduction of stream corrosive activity due to suggested solutions extends service life of equipment and pipelines at industrial catalytic dewaxing unit

Formalization of hydrocarbon conversion scheme of catalytic cracking for mathematical model development

The issue of improving the energy and resource efficiency of advanced petroleum processing can be solved by the development of adequate mathematical model based on physical and chemical regularities of process reactions with a high predictive potential in the advanced petroleum refining. In this work, the development of formalized hydrocarbon conversion scheme of catalytic cracking was performed using thermodynamic parameters of reaction defined by the Density Functional Theory. The list of reaction was compiled according to the results of feedstock structural-group composition definition, which was done by the n-d-m-method, the Hazelvuda method, qualitative composition of feedstock defined by gas chromatography-mass spectrometry and individual composition of catalytic cracking gasoline fraction. Formalized hydrocarbon conversion scheme of catalytic cracking will become the basis for the development of the catalytic cracking kinetic model

Четверта міжнародна наукова-практична конференція «Комп’ютерне моделювання в хімії і технологіях та системах сталого розвитку»

З використанням методу математичного моделювання створений розширений формалізований список з 110 компонентів, що вносять основний внесок у формування октанового числа бензинів. У середовищі Borland «Delphi 7» розроблений модуль автоматизованої обробки хроматограм, що дозволяє розробляти рецептури змішання товарних бензинів і реагувати на зміну складу сировини.The extended formalized set of 110 hydrocarbon components, key contributors in gasolines’ octane number formation, was created with applying of mathematic modeling. The new module of automatic chromatographic analysis data was developed in Borland «Delphi 7» workspace. It provides to develop recipes of trade gasolines blending and helps to respond the changes of raw materials composition.С использованием метода математического моделирования создан расширенный формализованный список из 110 компонентов, вносящих основной вклад в формирование октанового числа бензинов. В среде Borland «Delphi 7» разработан модуль автоматизированной обработки хроматограмм, позволяющий разрабатывать рецептуры смешения товарных бензинов и реагировать на изменение состава сырья

Three New Polyhydroxysteroids from the Tropical Starfish Asteropsis carinifera

Abstract-Thirteen steroidal compounds including three new polyhydroxysteroids, (24R,25S) 24 methyl 5α choles tane 3β,6α,8,15β,16β,26 hexaol, (22E,24R,25S) 24 methyl 5α cholest 22 ene 3β,6α,8,15β,16β,26 hexaol, and (22E,24R,25S) 24 methyl 5α cholest 22 ene 3β,4β,6α,8,15β,16β,26 heptaol, have been isolated along with ten pre viously known polyhydroxysteroids from the tropical starfish Asteropsis carinifera collected near the coast of Vietnam. The structures of the new compounds were elucidated by spectroscopic methods (mainly 2D NMR and ESI mass spec trometry)

Oceanalin B, a Hybrid α,ω-Bifunctionalized Sphingoid Tetrahydroisoquinoline β-Glycoside from the Marine Sponge Oceanapia sp.

Oceanalin B (1), an α,ω-bipolar natural product belonging to a rare family of sphingoid tetrahydoisoquinoline β-glycosides, was isolated from the EtOH extract of the lyophilized marine sponge Oceanapia sp. as the second member of the series after oceanalin A (2) from the same animal. The compounds are of particular interest due to their biogenetically unexpected structures as well as their biological activities. The structure and absolute stereochemistry of 1 as a α,ω-bifunctionalized sphingoid tetrahydroisoquinoline β-glycoside was elucidated using NMR, CD and MS spectral analysis and chemical degradation. Oceanalin B exhibited in vitro antifungal activity against Candidaglabrata with a MIC of 25 μg/mL

Molecular Cloning, Heterologous Expression, Purification, and Evaluation of Protein–Ligand Interactions of CYP51 of <i>Candida krusei</i> Azole-Resistant Fungal Strain

Due to the increasing prevalence of fungal diseases caused by fungi of the genus Candida and the development of pathogen resistance to available drugs, the need to find new effective antifungal agents has increased. Azole antifungals, which are inhibitors of sterol-14α-demethylase or CYP51, have been widely used in the treatment of fungal infections over the past two decades. Of special interest is the study of C. krusei CYP51, since this fungus exhibit resistance not only to azoles, but also to other antifungal drugs and there is no available information about the ligand-binding properties of CYP51 of this pathogen. We expressed recombinant C. krusei CYP51 in E. coli cells and obtained a highly purified protein. Application of the method of spectrophotometric titration allowed us to study the interaction of C. krusei CYP51 with various ligands. In the present work, the interaction of C. krusei CYP51 with azole inhibitors, and natural and synthesized steroid derivatives was evaluated. The obtained data indicate that the resistance of C. krusei to azoles is not due to the structural features of CYP51 of this microorganism, but rather to another mechanism. Promising ligands that demonstrated sufficiently strong binding in the micromolar range to C. krusei CYP51 were identified, including compounds 99 (Kd = 1.02 ± 0.14 µM) and Ch-4 (Kd = 6.95 ± 0.80 µM). The revealed structural features of the interaction of ligands with the active site of C. krusei CYP51 can be taken into account in the further development of new selective modulators of the activity of this enzyme