مجله فرآیند نو
پیاپی 70 (تابستان 1399)

Gasoline hydrotreating is a valuable and economical process for increasing gasoline quality, comparing with other refining processes. Observing harmful effects of some components in gasoline, like benzene, aromatics, olefins and sulfur compounds, which are detrimental to human health and environment and necessity of their removal, hydro treating process of gasoline is a matter of importance in the refining industry. The basis of this process is selective hydro treating of gasoline in sulfur removal reactor after removal of the cuts with boiling point less than 650°C in a fractionation tower to preserve Octane No. of final product. The sulfur removal of lighter cuts to the limit of 50 ppm needs a treating process which will result in octane loss. Therefore for the sulfur removal of this cut, a hydrogenation reactor is used before fractionation tower which its role is mainly hydrogenation of diolefines and olefines. Also it converts mercaptans to thiophenes. With this process, sulfur in lighter cut is transferred to heavier cut. And consequently the sulfur content of lighter cut is reduced to less than 50 ppm. This process is known as C.G.H (cracking gasoline hydrotreating) and its goal is producing gasoline with Euro.4 standard. In this study review and complete simulation of Imam Khomeimy Oil Refining Co. of Shazand has been done with the aid of Aspen Hysys software. Meanwhile in order to increase the quality and quantity of the gasoline of this unit, a new plan for process modification is presented which will improve the gasoline specification of this unit from Euro.4 to Euro.5 standard. However, the accuracy of the new plan is checked based on the calculations in the presented model. Finally design calculations related to new equipment changes of the plan implementation based on new process model and modified condition is done.

Membrane distillation, as a growing membrane technology, has gained worldwide attention over the past few decades. It is possible to desalinate seawater by using membrane distillation process. In this project, reduced graphene oxide was synthesized by a green chemical method. Then, the structure and properties of the synthesized reduced graphene oxide was evaluated by performing FTIR and FESEM analyzes. Next, the synthesized reduced graphene oxide was coated on the polyvinylidene fluoride membrane by vacuum filtration method. Then, structural and functional evaluation of the fabricated composite membrane was performed in vacuum membrane distillation process. The optimized composite membrane reached 99.99% of salt rejection and 11.8 LMH of flux.

Due to the reduction of fossil fuels resources the increase in the vacuum distillation residues which is left by the heavy petroleum products is a major problem in the oil industry, which has led researchers to pay more attentions to the turning of these heavy cuts into more valuable and useful products. Today, a variety of physical, chemical and, more recently, biological methods, as a cheap and bio-compatible method, are used to lighten the vacuum distillation tower residues. The present article is an overview of the various common methods for upgrading and lightening the heavy residue of the vacuum distillation tower.

The design and operation of pilot columns have long been considered as a prerequisite for the design of industrial-scale processes. Despite the obvious benefits, a few reactive distillation pilot plants have been set up. Researches have been shown that reactions such as esterification, transesterification, etherification, alkylation, dehumidification, acetylation and isomerization are best suited in reactive distillation columns. In general, the adaptation of the optimal temperature zone for the chemical reaction is the key parameter in designing reactive distillation columns. On the other hand, one of the most important preconditions for the implementation of these processes is the study of reactive azeotrope points. The diameter of the pilot columns used in most studies is 50 mm and the height of the columns varies according to the type of the process. Sulzer catalytic structured packing has been used mostly in these columns.

Earthing and protection of oil and gas storage tanks has always been one of the most challenging issues in the field of electrical engineering. Due to the high area of the tanks and its surroundings and the possibility of creating high step and touch voltages caused by lightning and passing its current and creating hazard for equipments and people around, as well as many fires that occur due to lightning and electrical charges in oil tanks, the need to study and research the grounding system of oil storage tanks is necessary. In this article, first, the existing design of a sample oil reservoirs in Said Beheshti Transportation Center and facilities of Isfahan Oil Pipelines and Telecommunications Company is discussed and critiqued. It has been computerized in CYMGDR and the values of step and touch voltages, as well as ground grid resistance value have been obtained and then compared with the standard values. The existing plan disadvantages have been studied and an optimal design is selected and recommended according to the environmental conditions and observations. Then, the current instructions for protection against lightning and static electricity in different standards have been studied and different methods of dealing with fire hazards of tanks have been reviewed and compared with existing tank conditions. Finally, some recommendations for optimizing the grounding and bonding of different tank components have been represented.

The purpose of this paper is to study the effect of cyber loafing on organizational citizenship behavior according to the role of moderating the demographic characteristics. This study is applied and in terms of data collection is descriptive - survey and correlation. Population of all staff of the national Iranian oil refining and distribution company Golestan –area was selected with a simple random sampling method of 138 people. Library studies were used to develop research literature and to test hypotheses using the field method. The data collection tool was questionnaire which was calculated and verified for validity by Cronbach's alpha coefficient (0.82) with SPSS22 software. To test the hypotheses with respect to the number of samples and the presence of a moderating variable, the model was used to model structural equation modeling and PLS software. The results showed that cyber loafing had a significant impact but negative on organizational citizenship behavior but the demographic characteristics of this relationship have not been moderating role.