A novel reactor concept for thermal integration of naphtha reforming with propane ammoxidation

In this study, propane ammoxidation as an exothermic process is thermally coupled with the endothermic naphtha reforming process which resulted in the elimination of the naphtha reforming furnaces. Both processes are available in petrochemical plants. Naphtha reforming produces aromatics (BTX, Toluene, Ethylbenzene) as well as hydrogen, while propane ammoxidation reactions on V-Sb-Al oxide catalyst produce acrylonitrile (ACN) as the main product which is a known intermediate for the production of various polymers and polyamides. In addition to energy saving, the aromatics production in the proposed scheme increased by 10% compared to conventional naphtha reforming (CNR). Furthermore, the effect of operating temperature, the number of tubes of the reactors, and the inlet molar flow rate of propane on the hydrogen production and aromatics yield in the naphtha reforming process have been investigated

Novel Chemical Looping Combustion Assisted Residue Fluid Catalytic Cracking Process in Order To Reduce CO₂ Emission and Gasoline Production Enhancement

In this novel study, application of chemical looping combustion (CLC) as the heat source for the endothermic residue fluid catalytic cracking (RFCC) process has been investigated to stabilize the RFCC riser temperature for increasing efficiency and proficiency of the process. A mathematical conceptual model has been presented to analyze the performance of RFCC process coupled with chemical looping combustion (RFCC-CLC). NiO18-α-Al₂O₃ particles have been employed as the oxygen carrier agents in CLC system, which have shown unprecedented reactivity and allow for working under high temperatures with complete conversion of CH₄ in RFCC-CLC configuration. This structure consisting of three coaxial vertical tubular reactors and the riser reactor is surrounded by the air and fuel reactors, respectively (all three reactors operate in the fluidized regime). The most illustrious advantage of applying CLC technique is the inherent CO₂ separation from flue gas. In addition, results indicate that methane conversion tends toward 1 and a 10% by weight increase in gasoline production and a 1.3% by weight reduction in coke formation have been achieved which reveals the supremacy of the RFCC-CLC configuration

Progress in spherical packed-bed reactors: Opportunities for refineries and chemical industries

Giving the ever-increasing energy and raw material demand as a result of global economy growth, revisiting the traditional reactor configuration designs (which are considered to be the heart of chemical industries) can significantly reduce the capital and operational costs while addressing the larger market demand for chemicals. The spherical-reactor geometry is an attractive alternative design to traditional tubular reactors due to its lower pressure drop (which is due to feed distribution over a larger outer surface area in spherical reactors compared to the cross sectional area in conventional tubular reactors) and recompression costs as well as construction material investment (reduced wall thickness to half). This review summarizes numerical modeling and experimental research on spherical reactors from 1958 to date. Several configurations of spherical reactors have been described and categorized. A review has been performed on modeling results of numerous arrangements and combinations of tubular and spherical reactors for industrial-scale reforming processes. The superiority of spherical packed bed reactors is further discussed and additional recommendations are provided to be considered in future research. As a general conclusion, spherical reactors could be considered as a potential candidate for pilot and industrial scale reactors due to their cost-effective designs and flexibilityof operation conditions

Progress in spherical packed-bed reactors:Opportunities for refineries and chemical industries

\u3cp\u3eGiving the ever-increasing energy and raw material demand as a result of global economy growth, revisiting the traditional reactor configuration designs (which are considered to be the heart of chemical industries) can significantly reduce the capital and operational costs while addressing the larger market demand for chemicals. The spherical-reactor geometry is an attractive alternative design to traditional tubular reactors due to its lower pressure drop (which is due to feed distribution over a larger outer surface area in spherical reactors compared to the cross sectional area in conventional tubular reactors) and recompression costs as well as construction material investment (reduced wall thickness to half). This review summarizes numerical modeling and experimental research on spherical reactors from 1958 to date. Several configurations of spherical reactors have been described and categorized. A review has been performed on modeling results of numerous arrangements and combinations of tubular and spherical reactors for industrial-scale reforming processes. The superiority of spherical packed bed reactors is further discussed and additional recommendations are provided to be considered in future research. As a general conclusion, spherical reactors could be considered as a potential candidate for pilot and industrial scale reactors due to their cost-effective designs and flexibilityof operation conditions.\u3c/p\u3

Cytotoxicity evaluation of extracts and fractions of five marine sponges from the Persian Gulf and HPLC fingerprint analysis of cytotoxic extracts

Objective: To screen the cytotoxic effects of some marine sponges extracts on HeLa and PC12 cells. Methods: Five marine sponges including Ircinia echinata (I. echinata), Dysidea avara, Axinella sinoxea, Haliclona tubifera and Haliclona violacea were collected from the Persian Gulf (Hengam Island). The cytotoxic effect of these sponges was evaluated by using MTT assay. The metabolic high performance liquid chromatography fingerprint of I. echinata was also carried out at two wavelengths (254 and 280 nm). Results: Among the sponges tested in this study, the extracts of I. echinata and Dysidea avara possessed the cytotoxic effect on HeLa and PC12 cells. The obtained fractions from high performance liquid chromatography were evaluated for their cytotoxic properties against the cell lines. The isolated fractions did not show significant cytotoxic properties. Conclusions: I. echinata could be considered as a potential extract for chemotherapy. Further investigation is needed to determine the accuracy of mechanism

Drimane-type Sesquiterpene Coumarins from Ferula gummosa Fruits Enhance Doxorubicin Uptake in Doxorubicin-resistant Human Breast Cancer Cell Line

Multidrug resistance (MDR) is the main cause of failure in the chemotherapy of cancer patients. The present study aimed to evaluate the effects of sesquiterpene coumarins of Ferula gummosa fruits on P-glycoprotein (P-gp)–mediated MDR. Drimane-type sesquiterpene coumarins from the fruits of F. gummosa were extracted with dichloromethane and subjected to column chromatography. The effects of the isolated compounds on P-gp–mediated MDR were evaluated in the breast cancer cell line MCF-7 which shows high resistance to doxoribicin (MCF-7/Dox). Phytochemical investigation of dichloromethane extract of F. gummosa fruits resulted in three sesquiterpene coumarins including conferone (1), mogoltacin (2), and feselol (3). The structures of these compounds were confirmed by 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy. Exposure of cells to conferone, mogoltacin, feselol, and verapamil (positive control) enhanced doxorubicin uptake by MCF-7/Dox cells. This effect was dose dependent, but varied with the structure of the chemical. At 25 μM, all the tested sesquiterpene coumarins restored at least 50% of the reference uptake (uptake by sensitive cells); but at 10 μM, their potency varied where conferone showed the highest potency and feselol showed the lowest potency. Conferone, mogoltacin, and feselol from F. gummosa suppress P-gp–mediated drug efflux in highly resistant human breast cancer cells