Terrace wall arrangement is one of the most common arrangements for methanesteam REFORMING reactor furnaces. In this work, a mathematical model of heat transfer in terrace wall furnaces has been developed. The model has been coupled with a reliable chemical reaction model to predict the behavior of an industrial steam-REFORMING reactor. The heat transfer model is similar to the zone method models, which considers heat conduction of the furnace walls in addition to the convective and radiative heat transfer. Among different operating variables, the effect of thermal conductivity of the furnace wall and the height of the burners on the performance of the reactor have been also studied.

The second period of the Abbasid caliphs (232-322 AH) with the emergence of several factors, some of which were rooted in the policies of the rulers of the first Abbasid period, the prestige and concentration along with the authority of the caliphate institution faced a serious and deteriorating challenge. The caliphate system was a toy in the hands of the power-seekers who had seized the sovereign affairs. A few of the caliphs of the period started and pursued reformist efforts in various elements in order to restore the former status of the mentioned institution and, according to their belief, by identifying structural damages, gaining the satisfaction of the people and the properties of the society, and restoring the basic position of the caliphate. In the present research, it is tried to analyze the set of actions of reformer caliphs based on library studies and descriptive-analytical method. The findings of research mean that reform efforts in political, economic, military, social and scientific-educational dimensions have been more or less visible; But the achievements have not left a significant impact on the reform of the structure and its continuity.

This paper aims to show the impact of fear of God, as one of the most important signs of religious spirituality, on improving sexual and gender relationships in family and society as well as other social relationships and thus to offer some procedures for enhancing and expanding this character at familial and societal levels in order to reduce the problems involved in social relations specially male-female relations. With respect to the approach, a three-dimensional method which employs religious texts, sociological insight and social engineering standpoint could be seen in the article. And with regard to the value, it could be said that although fearing God is a familiar doctrine and its desirable societal outcomes specially the prevention of deviances are not deniable, reminding this nearly forgotten virtue and explaining its societal outcomes in detail could be taken as a considerable contribution to the literature of sociology of religion. Meanwhile the application of this discussion to the problems of sociology of family and sociology of gender could be considered as an important contribution to the literature of these two fields.

This article describes "Managing Privatization based on Goals" as a policy for REFORMING public enterprises. The author believes that selling of public enterprises to the private sector, which has been introduced to the world since the 80s, is not the only way of privatization and non-selling alternations are of great significance and should be considered carefully. This viewpoint is based on the reduction in size of the government while there is an emphasis on coordination between the state and the market. Nevertheless, there is a need for assessing the social, political and cultural conditions of the country and priorities in policy making; so that before the state brings about any changes in the role of public enterprises, it can use the effective alternatives for their special goals and situations. This article introduces the ways to manage privatization by suggesting different alternatives for different goals and situations. It can provide the state with some approaches that are useful in REFORMING those enterprises which should stay under its control, or which are not ready to be offered to the private sector.

Mesoporous nanocrystalline zirconia powders with high specific surface area and stable tetragonal crystallite phase were prepared by surfactant assisted precipitation method. The obtained results showed that the nanocrystalline zirconia powders have a good potentional as catalyst support in natural gas REFORMING with carbon dioxide. The activity results indicated that the nickel catalyst with 5 wt.% nickel loading showed stable activity for syngas production with a decrease of about 4% in methane conversion after 50 h of reaction. Addition of promoters (CeO2, La2O3, MgO and K2O) to the catalyst improved both the activity and stability of the nickel catalyst and increased the nickel dispersion and had a positive effect in preventing coke formation. The nickel catalyst (5% Ni–3% CeO2/ZrO2) showed high catalytic stability under severe reaction conditions for more than 1550 h on stream. Based on our knowledge, there is no prior documentation for a nickel catalyst that is comparable to this catalyst in catalyst stability under the reaction conditions employed in this study.

Renewable energy is generally defined as energy that is collected from renewable resources such as wind, sunlight, rain, waves, and geothermal heat. Hydrogen is produced using a number of non-renewable and renewable resources such as fossil fuels and biomass. The other feedstock for hydrogen is water in electrolysis process. Microorganisms such as bacteria and algae can produce hydrogen through biological processes. Hydrogen is produced in some processes as a byproduct. In some processes, the produced hydrogen along with other by-products is sent to flare; however, it can be processed as an energy resource. In this paper, hydrogen production via Methane steam REFORMING process is investigated. The simulation results show that separation of produced hydrogen provides a significant energy source for mentioned chemical reaction.

Ethanol, as a substance that can be produced from both renewable and non-renewable sources, can be used as fuel, additive to fuel or transformed into other energy carriers. Therefore; The use of pure ethanol or its conversion to other compounds has been considered by researchers. In this paper, the ethanol REFORMING processes are simulated for synthesis gas production using Aspen HYSYS . The studied processes include ethanol steam REFORMING, ethanol dry REFORMING, ethanol steam and dry REFORMING and ethanol tri-REFORMING. The simulation results showed that the highest conversion belongs to ethanol tri-REFORMING by 99.60% while the lowest conversion is related to ethanol steam REFORMING by 96.95%. In addition; conversion of dry REFORMING, parallel and cascade arrangement of reactors were obtained by 99.39%, 98.15% and 99.41%, respectively. H2/CO were obtained for steam REFORMING by 2.19-4.22, dry REFORMING by 1, parallel arrangement of steam and dry REFORMING of ethanol by 1.2-2.94, cascade arrangement of steam and dry REFORMING of ethanol by 1.1-2.93, and tri-REFORMING of ethanol by 2.01-3.40.

The main goal of this research is dynamic modeling and optimization of the steam methane REFORMING process in an industrial hydrogen plant in a crude oil refinery. In the first step, the process is heterogeneously modeled based on the mass and energy balance equations considering catalyst deactivation. Since the REFORMING reactions are under mass transfer control in the catalyst, the effectiveness factor is calculated and applied in the model. Then, to verify the accuracy of the model, the simulation results are compared with the plant data. The simulation results show that hydrogen production capacity decreases and approaches from 27. 4 to 24. 4 mole/s due to catalyst deactivation. In the next step, considering the uniform hydrogen production as an objective function and operational limitations in the process, a single objective optimization problem is formulated to overcome the production decay. Based on the formulated optimization problem, the optimal dynamic trajectories of feed temperature, furnace temperature, and steam to methane ratio are calculated during the process run time. Based on the simulation results, the hydrogen production is improved by about 6% applying optimal conditions to the system.