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No / One of the more difficult tasks in the petroleum refining industries that have not been considered largely in the literature is hydrotreating (HDT) of crude oil. The accurate calculations of kinetic models of the relevant reaction scheme are required for obtaining helpful models for HDT reactions, which can be confidently used for reactor design, operating and control. In this work, an optimization technique is employed to evaluate the best kinetic models of a trickle bed reactor (TBR) process utilized for hydrodenitrogenation (HDN) and hydrodemetallization (HDM) that includes hydrodevanadization (HDV) and hydrodenickelation (HDNi) of crude oil based on pilot plant experiments. The minimization of the sum of the squared errors (SSE) between the experimental and estimated concentrations of nitrogen (N), vanadium (V) and nickel (Ni) compounds in the products is used as an objective function in the optimization problem to determine the kinetic parameters. A series of experimental work was conducted in a continuous flow isothermal trickle bed reactor, using crude oil as a feedstock and the commercial cobalt¿molybdenum on alumina (Co¿Mo/¿-Al2O3) as a catalyst. A three-phase heterogeneous model based on two¿film theory is developed to describe the behaviour of crude oil hydroprocessing in a pilot¿plant trickle bed reactor (TBR) system. The hydroprocessing reactions have been modelled by power law kinetics with respect to nitrogen, vanadium and nickel compounds, and with respect to hydrogen. In this work, the gPROMS (general PROcess Modelling System) package has been used for modelling, simulation and parameter estimation via optimization. The model simulations results were found to agree well with the experiments carried out in a wide range of the studied operating conditions. The model is employed to predict the concentration profiles of hydrogen, nitrogen, vanadium and nickel along the catalyst bed length in three phases.

No / Fossil fuel is still a predominant source of the global energy requirement. Hydrotreating of whole crude oil has the ability to increase the productivity of middle distillate fractions and improve the fuel quality by simultaneously reducing contaminants such as sulfur, nitrogen, vanadium, nickel and asphaltene to the levels required by the regulatory bodies. Hydrotreating is usually carried out in a trickle bed reactor (TBR) where hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodemetallization (HDM) and hydrodeasphaltenization (HDAs) reactions take place simultaneously. To develop a detailed and a validated TBR process model which can be used for design and optimization of the hydrotreating process, it is essential to develop kinetic models for each of these reactions. Most recently, the authors have developed kinetic models for all of these chemical reactions except that of HDAs. In this work, a kinetic model (in terms of kinetic parameters) for the HDAs reaction in the TBR is developed. A three phase TBR process model incorporating the HDAs reactions with unknown kinetic parameters is developed. Also, a series of experiments has been conducted in an isothermal TBR under different operating conditions affecting the removal of asphaltene. The unknown kinetic parameters are then obtained by applying a parameter estimation technique based on minimization of the sum of square errors (SSEs) between the experimental and predicted concentrations of asphaltene compound in the crude oil. The full model with the estimated kinetic parameters is then applied to evaluate the removal of asphaltene (thus affecting fuel quality) under different operating conditions (than those used in experiments).

Yes / The present study explored a novel oxidative desulfurization (ODS) method of light gas oil fuel, which combines a catalytic oxidation step of the dibenzothiophene compound directly in the presence of molecular air as oxidant to obtain high quality fuel for light gas oil. In chemical industries and industrial research, catalysis play a significant role. Heightened concerns for cleaner air together with stricter environmental legislations on sulphur content in addition to fulfill economic have created a driving force for the improvement of more efficient technologies and motivating an intensive research on new oxidative catalysts. As the lower quality fuel becomes more abundant, additional challenges arise such as more severe operation conditions leading to higher corrosion of the refinery installations, catalyst deactivation and poisoning. Therefore, among the technologies to face these challenges is to develop catalysts that can be applied economically under moderate conditions. The objective of this work is to design a suitable synthetic catalyst for oxidative desulfurization (ODS) of light gas oil (LGO) containing model sulphur compound (dibenzothiophene (DBT)) using air as oxidant and operating under different but moderate operating conditions. The impregnation method is used to characterize two homemade catalysts, cobalt oxide (Co3O4/γ-Al2O3) and manganese oxide (MnO2/γ-Al2O3). The prepared catalysts showed that the manganese oxide has a good impregnation (MnO2=13%), good pore size distribution and larger surface area. A set of experiments related to ODS of dibenzothiophene has been carried out in a continuous flow isothermal trickle bed reactor using light gas oil as a feedstock utilizing both catalysts prepared in-house. At constant pressure of 2 bar and with different initial concentration of sulphur within dibenzothiophene, the temperature of the process was varied from 403K to 473K and the liquid hourly space velocity from(LHSV) was varied from 1 to 3 hr-1. The results showed that an increase in reaction temperature and decreasing in LHSV, higher conversion was obtained. Although both catalysts showed excellent catalytic performance on the removal of molecule sulphur compound from light gas oil, the catalyst MnO2 catalyst exhibited higher conversion than Co3O4 catalyst at the same process operating conditions.

Yes / Among several treatment methods Catalytic Wet Air Oxidation (CWAO) treatment is considered as a useful and powerful method for removing phenol from waste waters. In this work, mathematical model of a trickle bed reactor (TBR) undergoing CWAO of phenol is developed and the best kinetic parameters of the relevant reaction are estimated based on experimental data (from the literature) using parameter estimation technique. The validated model is then utilized for further simulation and optimization of the process. Finally, the TBR is scaled up to predict the behavior of CWAO of phenol in industrial reactors. The optimal operating conditions based on maximum conversion and minimum cost in addition to the optimal distribution of the catalyst bed is considered in scaling up and the optimal ratio of the reactor length to reactor diameter is calculated with taking into account the hydrodynamic factors (radial and axial concentration and temperature distribution).

Gratitude is an emotion with a number of positive benefits for both individuals and organizations; however, very little research has addressed the role of leaders in influencing the gratitude of those they lead. Organizational leaders can increase the gratitude levels of the leaders who report to them, who then can influence the gratitude of their own subordinates. This study addresses how the emotion of gratitude can trickle-down through two levels of an organizational hierarchy. There are two potential theories to support such trickle-down effects of gratitude: a behavioral explanation in social learning theory and an affective explanation in gratitude as an emotional contagion. Social learning theory can explain how gratitude trickles via the influence role models (i.e., leaders) have on the behavior of those below them. In addition, gratitude as an emotional contagion can unconsciously increase feelings of gratitude after experiencing gratitude expressions and these feelings of gratitude should increase the spread of gratitude to others. An experimental study design consisting of students acting as supervisors and subordinates evaluating email manipulations was used to test the hypotheses. The results from this study support the idea that gratitude can spread from upper-level leaders to lower levels in an organizational hierarchy. In addition, results suggest that this relationship is positively mediated by role modeling effects supporting the behavioral explanation of trickle-down effects. However, results did not support emotional contagion theory as a mechanism that explains trickle-down effects. Such findings offer important implications as leaders can play a significant role in spreading the positive effects of gratitude throughout their organization.

Yes / Phenol and phenolic derivatives found in different industrial effluents are highly toxic and extremely harmful to human and the aquatic ecosystem. In the past, trickle bed reactor (TBR), reverse osmosis (RO) and other processes have been used to remove phenol from wastewater. However, each of these technologies has limitations in terms of the phenol concentration in the feed water and the efficiency of phenol rejection rate. In this work, an integrated hybrid TBR-RO process for removing high concentration phenol from wastewater is suggested and model-based simulation of the process is presented to evaluate the performance of the process. The models for both TBR and RO processes were independently validated against experimental data from the literature before coupling together to make the hybrid process. The results clearly show that the combined process significantly improves the rejection rate of phenol compared to that obtained via the individual processes.

This study focuses on the reformation of the cross-border political coalition in the Scandinavian region of Öresund, specifically the re-organization of Öresundskommitteen to Greater Copenhagen & Skåne Committee. Through the lens of Critical Discourse Analysis, the study critically examines the newly advocated regional strategy focusing on international place marketing of the collective brand Greater Copenhagen, underlying power structures and incentives of the reformation as well as the subsequent consequences for the regional development. The result highlights a political shift of focus, from the region in general to Copenhagen in particular, justified by the conviction of growing international competition and the regional core as undisputable ‘growth-machine’ for the whole region. Consequently, local projects can be legitimized as regional concerns, potentially supporting misallocation of regional funds, political and core-periphery polarization.

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