مجله فرآیند نو
پیاپی 63 (پاییز 1397)

The light naphtha isomerization patents were technically categorized into 5 groups of process, catalyst, isolation, reactor and pre-treatment. The largest number of patents is in the process and catalyst fields mainly filed by UOP and Shell companies. The highest number of patents were registered in the 1960s. The patents published by UOP are the most widely cited. Largest number of patents are filed in the United States which reveals that US is the main target market for isomerization process. Three groups of aluminum chloride, zeolite and metal oxide catalysts such as platinum, palladium and rhodium have been used on chlorine alumina support, which is chosen as the optimal catalyst according to the feed, operating conditions and product. There are two main separation techniques for fractionation of normal paraffin from isoparaffin; namely, molecular sieve towers or DIH towers (Deisohexanizer) and DIP (Deisopentanizer) which are placed before or after the reactor.

In this study, supersonic nozzle is introduced as a high pressure system capable of separating condensate gas from natural gas. One of the most important advantages of this system is that the pressure recovery is largely in the divergent region of the nozzle during the shock wave phenomenon. On the other hand, the supersonic nozzle do not have rotating equipment and their use does not require energy. For modeling of supersonic separators, a series of nonlinear equations were solved numerically using MATLAB and HYSYS software. In this investigation, the effect of temperature, pressure and flow rate of feed inlet, return pressure on nozzle output and flow behavior inside nozzle are evaluated. The results of present work show that the selective separation of water and gas condensates by increasing the inlet pressure at constant temperature, increasing the inlet temperature at a constant outlet pressure and controlling the return pressure is feasible.

Residual oil in the storage tanks usually lead to accumulation of oily sludge which should be treated and disposed in a suitable manner. In this paper, the bacterial consortium of oil sludge in Kermanshah plant wastewater was used for treatment of oily slug in storage tanks. Broth culture was used for culturing bacteria. In this work, effect of many parameters on degradation process was investigated such as temperature, pH, oily slug content, phosphate ion, residence time and humidity. Results show that the maximum of microorganisms efficiency was in pH of 7.5 and the temperature of 30oC. Removal of hydrocarbons was decreased in both increase of phosphate ion and decrease of humidity. Also the results indicated that the use of microorganisms in the refinery wastewater treatment of oily sludge in storage tank was an efficient, inexpensive method, and also reduced hydrocarbons to acceptable levels.

By applying new processes (Progressive or Distributed Sequences) in Crude Oil distillation process a significant amount of energy consumption and environmental effluents could be reduced. Although, the new processes are not operational and tested in real industries, but their economic and environmental performance was confirmed by different researchers. In this work by considering imposing prices of environmental effluents and energy consumptions, it is illustrated that, the new processes could be a good replacement for conventional process in new established refineries. The analysis of these new configurations for a light and heavy oil sample of Iran, illustrate that the progressive and distributed distillation sequences could be a suitable replacement for traditional crude oil distillation systems in Iran. The gross profit of the products of new processes are 0.13 and 12.13 MM$/year more than conventional process for light and heavy oil respectively.

In the recent years, hydrogen and synthesis gas are major raw materials for petroleum, gas and petrochemical industries. Demands for these gases all days are increased. By considering consuming of hydrogen and synthesis gas in different industries, it is mandatory to investigate economic and environmental-friendly process for producing thesis gases. Various methods for production of synthesis gas are: coal gasification, steam reforming of methane, partial oxidation of methane, auto thermal reforming of methane, dry reforming of methane and tri-reforming of methane. In this work, several researches about dry reforming of methane plus coupling of several methods have been introduced. Investigated results indicate that dry reforming of methane produces synthesis gases for downstream process by reduction of green house gases emission to environment can be good alternative of currently process.

With considering the accessibility limitation of industrial units piping and with the aim of accelerating pipes installation, spool pre-fabrication perform a process. As a simple definition, the spool is a complex of parts and the related joints. Spools priorities determination in the piping process is one of the most important stages of the project. On the other hand, using the complicated sequencing models, since their effortful and time-consuming nature, make solving the problem so difficult. Therefore, providing a decision-making approach to increase accuracy and comprehensiveness is necessary. In this paper, we used the simple weighted sum and complex proportional assessment method as the simple, understandable and fast decision-making methods in the industrial numerical example and, By the way, we reviewed and introduced the important priorities in spool pre-fabrication. Finally, the obtained results and the related comparisons with the intuitive values represent reasonability and practicality.