sulfur and nitrogen compounds
Recently Published Documents


TOTAL DOCUMENTS

69
(FIVE YEARS 18)

H-INDEX

17
(FIVE YEARS 2)

Author(s):  
Souad Hammadou née Mesdour ◽  
Djamila Boufadès ◽  
Hassina Boussak ◽  
Abdesselem Saoud ◽  
Soraya Demim ◽  
...  

ACS Omega ◽  
2021 ◽  
Author(s):  
Hurun E. Suhaimi ◽  
Hanee F. Hizaddin ◽  
Irfan Wazeer ◽  
Lahssen El Blidi ◽  
Mohd A. Hashim ◽  
...  

2021 ◽  
Vol 2 (2) ◽  
pp. 382-391
Author(s):  
Dinis F. Silva ◽  
Alexandre M. Viana ◽  
Fátima Mirante ◽  
Baltazar de Castro ◽  
Luís Cunha-Silva ◽  
...  

An effective process to remove nitrogen-based compounds from fossil fuels without harming the process of sulfur removal is an actual gap in refineries. A success combination of desulfurization and denitrogenation processes capable of completely removing the most environmental contaminates in diesel under sustainable conditions was achieved in this work, applying polyoxometalates as catalysts, hydrogen peroxide as oxidant, and an immiscible ionic liquid as an extraction solvent. The developed process based in simultaneous oxidative desulfurization (ODS) and oxidative denitrogenation (ODN) involved initial extraction of sulfur and nitrogen compounds followed by catalytic oxidation. Keggin-type polyoxomolybdates revealed much higher reusing capacity than the related polyoxotungstate. Effectively, the first catalysts practically allowed complete sulfur and nitrogen removal only in 1 h of reaction and for ten consecutive cycles, maintaining the original catalyst and ionic liquid samples.


Author(s):  
Eli H. Olmos-Cerda ◽  
Georgina C. Laredo ◽  
Patricia Pérez-Romo ◽  
Ricardo Águeda-Rangel ◽  
Alfonso García-López

Abstract The study of the best experimental conditions and catalyst for the hydrogenation (HYD) of light cycle oil (LCO) for upgrading purposes was carried out. The objective was to examine the ability of two commercial hydrotreatment (HDT) catalysts for selective aromatic saturation. The effect of the hydrotreatment operation parameters (temperature, pressure, liquid hourly space velocity, H2/HC ratio) on the sulfur and nitrogen contents and in the saturation of aromatic hydrocarbons was also investigated. The goal was to obtain the highest conversion to mono-aromatic hydrocarbons from this di-aromatic (naphthalene derivatives) type feedstock, and at the same time to get reasonable hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) performance to avoid contaminant hydrocarbons for the next step (usually hydrocracking, HCK). An appropriate hydrotreated product with the highest concentration of mono-aromatic derivatives, a minimum reduction on the total aromatic content, and suitable decrements of sulfur and nitrogen compounds, was achieved using a cobalt-molybdenum supported on alumina catalyst, at 330 °C, 5.5 MPa, and a liquid hourly space velocity of 1.1 h−1. Additionally, the kinetics of the HDA was studied, assuming a lump characterization into tri-, di- and mono-aromatic and aliphatic hydrocarbons, pseudo-first-order reaction rates between these conversions, and thermal losses and diffusional resistances to be undetectable.


Author(s):  
N. Evelin Paucar ◽  
Peyton Kiggins ◽  
Bryson Blad ◽  
Karl De Jesus ◽  
Farjana Afrin ◽  
...  

2020 ◽  
Vol 14 (3) ◽  
pp. 203-228
Author(s):  
Asmaa Nabil-Adam ◽  
Mohamed A. Shreadah ◽  
Nehad M. Abd El-Moneam ◽  
Samy A. El-Assar

Background: Gracilaria has been shown to be an important source of marine bioactive natural biomaterials and compounds. Although there are no enough patents used Gracilaria worldwide, the current study tries to put the Gracilaria on the spot for further important patents in the future. Methods: Different advanced experimental models and analytical techniques, such as cytotoxicity, total antioxidant capacity, anticancer, and anti-inflammatory profiling were applied. The phytochemical analysis of different constituents was also carried out. Results: The mineral analysis revealed the presence of copper (188.3 ppm) and iron (10.07 ppm) in addition to a remarkable wealth of selenium and sulfur contents giving up to 36% of its dry mass. The elemental analysis showed high contents of sulfur and nitrogen compounds. The GCMS profiling showed varieties of different bioactive compounds, such as fatty acids, different types of carotenoids in addition to pigments, alkaloids, steroids. Many other compounds, such as carbohydrates and amino acids having antioxidant, anti-inflammatory, and antiviral activities, etc. were identified. The cytotoxicity activity of Gracilaria marine extract was very effective against cancerous cell lines and showed high ability as a potent antitumor due to their bioactive constituents. Specialized screening assays using two anticancer experimental models, i.e., PTK and SKH1 revealed 77.88% and 84.50% inhibition anticancer activity; respectively. The anti-inflammatory activities investigated using four different experimental models, i.e., COX1, COX2, IL6, and TNF resulted in 68%, 81.76%, 56.02% and 78.43% inhibition; respectively. Moreover, Gracilaria extracts showed potent anti-Alzheimer with all concentrations. Conclusion: Gracilaria proved to be a multi-product source of marine natural products for different biotechnological applications. Our recommendation is to investigate the Gracilaria bioactive secondary metabolites in order to create and innovate in more patents from current important seaweeds (Gracilaria).


Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 896
Author(s):  
Magdalena Mosinska ◽  
Malgorzata I. Szynkowska ◽  
Pawel Mierczynski

Nowadays, the reforming of natural gas is the most common of hydrogen or syngas generation process. Each reforming process leads to the achievement of specific goals and benefits related to investment costs. The disadvantage of the reforming process is the need to preclean it mostly from the sulfur and nitrogen compounds. The solution to this problem may be liquefied natural gas (LNG). Liquefied natural gas has recently been seen as an energy source and may be a promising replacement for natural gas. The constant development of the pipeline network, safe transport and a lot of advantages of LNG were contributed to the research development related to the usage of LNG in energy generation technologies. The presented review is a literature discussion on the processing of methane used to produce hydrogen with particular emphasis on the processes of oxy-steam reforming of natural or liquefied natural gas (OSR-LNG). In addition, a key consideration in this article includes Ni catalyst systems used in the oxy-steam reforming of methane or LNG reactions. An analysis of the OSR process conditions, the type of catalyst and the OSR of the methane reaction mechanism may contribute to the development of a modern, cheap catalyst system, which is characterized by high activity and stability in the oxy-steam reforming of natural gas or LNG (OSR-LNG).


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Gąsior ◽  
Aldona Kawęcka ◽  
Krzysztof Wojtycza ◽  
Jacek Sikora

AbstractIn order to characterize the volatile compounds composition of lamb meat, 3 groups of baked leg muscle samples from two Polish native sheep breeds: Świniarka aged 9 months (S9), Wrzosówka aged 9 months (W9), and Wrzosówka aged 7 months (W7), were analyzed by HS-SPME-GC/MS, followed by multivariate statistics comprising the F-Ratio method for variables pre-selection, and PCA-LDA analysis. Ninety seven volatile compounds were determined, out of which 74 were identified. The largest classes of volatile compounds were aldehydes and furans followed by alcohols, hydrocarbons, ketones, and sulfur and nitrogen compounds. Statistically significant differences between the S9, W9, and W7 groups were observed for 11 volatiles, i.e.: pentanal; hexanal; 1,3-octadiene; benzaldehyde; 3-ethyl-2-methyl-1,3-hexadiene; 3-octen-2-one; 2-octenal; 2-hexylfuran; tetradecanal; pentadecanal; hexadecanal. The HS-SPME-GC/MS method coupled with chemometrics, based on the relative intensity spectral data of these volatiles, proved to be an effective tool for the discrimination of lambs according to breed and age. The classification accuracy value for the S9, W9, and W7 groups was 100%.


Author(s):  
Sabrina Beckmann ◽  
Ibrahim F. Farag ◽  
Rui Zhao ◽  
Glenn D Christman ◽  
Nancy G Prouty ◽  
...  

AbstractAuthigenic carbonates represent a significant microbial sink for methane, yet little is known about the microbiome responsible for the methane removal. We identify carbonate microbiomes distributed over 21 locations hosted by 7 different cold seeps in the Pacific and Atlantic Oceans by carrying out a gene-based survey using 16S rRNA- and mcrA gene sequencing coupled with metagenomic analyses. These sites were dominated by bacteria affiliated to the Firmicutes, Alpha- and Gammaproteobacteria. ANME-1 and −2 clades were abundant in the carbonates yet their typical syntrophic partners, sulfate reducing bacteria, were not significantly present. Our analysis indicated that methane oxidizers affiliated to the ANME-1 and −2 as well as to the Candidatus Methanoperedens clades, are capable of performing complete methane- and potentially short-chain alkane oxidations independently using oxidized sulfur and nitrogen compounds as terminal electron acceptors. Gammaproteobacteria are hypothetically capable of utilizing oxidized nitrogen compounds in potential syntrophy with methane oxidizing archaea. Carbonate structures represent a window for a more diverse utilization of electron acceptors for anaerobic methane oxidation along the Atlantic and Pacific Margin.


2020 ◽  
pp. 183-192
Author(s):  
Nina N. Gorlova ◽  
Gennady V. Medvedev

A significant negative impact on the environmental components (atmosphere and hydrosphere) is provided by water transport as a result of the use of “heavy” fuels and the lack of effective exhaust gas purification systems. One of the technologically and cost-effective is the cleaning of spent marine power plants using catalytic converters. An optimal degree of purification of exhaust gases from sulfur and nitrogen compounds is ensured by using catalytic materials in porous permeable SHS purification systems.


Sign in / Sign up

Export Citation Format

Share Document