1- INTRODUCTION Because of the exchange fluctuations in Iranian economy, the capital market has undergone significant changes. the petroleum products stock index has the largest share in the capital market price index compared to currency industries. the present study tries to investigate the impact of the exchange rate crisis on the petroleum products stock index in Tehran stock exchange by using the monthly data of the period of 2009:1-2020:3 and using the nonlinear Markov switching approach. 2- THEORETICAL FRAMEWORK Due to the high dependence of foreign exchange reserves on the oil foreign exchange receipts (DEXO) and the sharp decline in these receipts, the central bank has faced limitations in supplying the foreign exchange to the market. thus, reducing the currency resources and supplying the foreign exchange on the one hand, and the growth of the foreign exchange demand on the other hand, have caused the raise in the exchange rate. Economic sanctions have always affected the foreign exchange market, the extent of which depends on the severity of the sanctions. the most important reason for the volatile increase in the exchange rate in recent years is the oil and banking sanctions against our country. economic sanctions will significantly reduce the oil and non-oil exports by restricting the purchasing of the trading partners, and through the channel of declining the foreign exchange earnings will lead to a decrease in the supply of the foreign exchange, and consequently a sharp increase in the exchange rate (devaluation of the national currency). now, we turn to the mechanism of transferring the currency crisis to the stock prices. Changes in the exchange rates can have two different impacts on the stock prices. on the one hand, the increase in the exchange rate (in terms of demand) has led to an increase in the income of the exporting companies (such as refineries, petrochemicals, metals, mining, etc.) and, consequently, their stock prices, and on the other hand (based on the supply), leads to lower profits for the importing companies such as some automotive, pharmaceutical and food industries, as well as the transportation and leads to lower stock prices. In addition to dividends, stock buyers also pay attention to the changes in the company's intrinsic value. the intrinsic value of industries whose creation and operation require the supply of machinery from abroad, is affected by the exchange rate changes. and if a company imports the machinery at lower exchange rates, the intrinsic value of the company will increase as the exchange rate increases, and this intrinsic increase intensifies when the establishment of a similar company is not possible due to the high exchange rate, and if the company's products are produced exclusively, its demand will increase and the company's profit will be higher over time. on the other hand, the share of depreciation cost of machinery in the cost of goods produced by the company decreases. considering the above cases by investors, the demand for the shares of these companies will increase and this will increase the stock prices of these companies. in addition, if the exchange rate decreases over time, it will cause the opposite effect for these companies. 3- METHODOLOGY Recently, the use of the nonlinear models in fluctuation studies has expanded because of this assumption that the linearity of the exchange fluctuations is a large and unrealistic limitation for these studies. this pattern is also known as the pattern of the regime change. the regime change means that a policy variable may show a behavior in one period of time and behave differently in another time period. therefore, if this issue is not considered in the study of the behavior of the variable, the biased results will be obtained. markov rotation models, as the nonlinear models, are able to model the behavioral pattern of the changing status of the dependent variable over time. in nonlinear models, it is assumed that the behavior of the variable on which the modeling is performed is differently and changes in different states. For this purpose, among the various modes of Markov switching model, MSIAH (2) –VAR (2) has been selected. 4- RESULTS & DISCUSSION The empirical findings of the study show that only in a regime with high fluctuations (first regime), the exchange rate is the causal relationship of the petroleum products stock index and the increase in the exchange rate has increased the petroleum products stock index, while the petroleum products stock index has no impact on the exchange rate. In addition, the results indicate that the sustainability of the petroleum products stock index in the regime with the low fluctuations (second regime) was more than of the regime with the high fluctuations (first regime). 5- CONCLUSIONS & SUGGESTIONS Due to the results of the present study, there is a one-way relationship between high exchange rate fluctuations and the stock index of petroleum products. investors active in the stock market, in addition to considering how the stock index of petroleum products is affected by other influential domestic variables, should also consider high exchange rate fluctuations and make their decisions. it is suggested that shareholders, in order to benefit from the growth of the capital market index, as soon as the exchange rate rises sharply, buy shares of companies exporting goods, such as refineries, petrochemicals, metals, mining, etc. also, as soon as the exchange rate falls sharply, sell the shares of the mentioned companies and buy the shares of companies independent of the exchange rate in order not to suffer from the risk of a decrease in the stock index.

Oil refining is a joint production system because the production of one oil product makes technically inevitable the production of other oil products. Due to the complex nature of the process involved and the vast number of joint product outputs that are strongly correlated, it is very difficult to establish any meaningful CO2 emissions allocation between oil products. Nevertheless, the allocation of petroleum refinery energy use and the resultant CO2emissions among different oil products is necessary in "well to wheel" analysis in order to evaluate the environmental impacts of individual transportation fuels.In practice, allocation methods used so far for the petroleum based fuel are traditionally based on two fundamental approaches: physical 'measures (mass, volume, energy contents or other relevant parameters) or market value of individual oil products from a given refinery. These methods are open to discussion on two points. Fist, an a priori assumption about the allocation procedure (i.e., mass, volume, energy contents, market value, etc.) is in some ways completely arbitrary and consequently of little use for economic decision making purposes. Second, these approaches ignore the opportunity cost effects and the interdependencies which might exist among the refinery process units, and systematically assign more emissions to the oil products that utilize more process units.More sophisticated proposals to energy consumption and emissions allocation have been developed based on the concept of duality in linear programming (LP). Unfortunately, in refinery LP models constraints on (fixed) unit process capacities or input availabilities might destroy the additivity property of the marginal based allocations. In fact, due to a technical feature inherent in LP, the petroleum product allocation coefficients might underestimate or overestimate the total volume of the refinery's CO2 emissions. This handicap is a valid objection to LP as an allocation tool in retrospective or accounting LCA studies and might limit its use for problems in which the objective is to assign unambiguously the whole refinery's emissions among the oil products. This practice-oriented paper is aimed to provide a two-stage procedure, based on LP, to fully allocate the refinery's CO2emissions among the refinery's petroleum joint products. The procedure is applied to the IFP (Institut FranÇais du Pétrole) oil refinery. The average contribution of petroleum oil products to the refinery's CO2 emissions are then compared with the other accounting allocation methods. We show that, contrary to these latter, gasoline has not always a higher average CO2 content than that of diesel within the European refineries.

This article analyzes the possibility of natural gas substitution instead of petroleum products (gasoline, kerosene, gas oil. fuel oil, LPG) in Iran, by modeling in two different frames and in three economic sectors (residential - commercial, industrial and transport). In the first frame, by using the panel analysis, different models for the demand of natural gas and petroleum products are estimated. Then, the demand of natural gas and petroleum products and the trend of substitution in economic sectors for the period 2006-2017 are forecasted and analyzed. In the second frame, by using the previous data, the modeling of Translog functions, with seemingly unrelated regressions, in two economic sectors (residential, commercial and industrial), which are the main natural gas consumers, is performed. The earned price elasticities of demand show the substitution between natural gas and oil products in the past and current years, but, due to low elasticities, the trend of this substitution is slow.

Background: Loading of petroleum products consists of several parts, of which the arm platform section is known to be the source of most accidents. Objectives: Therefore, this study was done to evaluate the risk of arm loading platforms using the bow-tie analysis (BTA) technique to identify the causes and the probability of occurrence of hazardous events. Methods: In this study, wefirst identified the risks of the loadingarmusing the expert’ s judgment. The risk of overflow is considered as the top event. Then, the basic events were identified by the fault tree analysis (FTA), and the possible consequences of the top event were predicted using the event tree. Next, using the computational equations, the probability of spilloverandits consequences were calculated. The path of the risk event from the causal phase to the consequent phase was also illustrated by sketching the structure of the BTA. Results: A total of 14 basic events and 8 intermediate events were involved in the occurrence of the top event, and 5 consequences were identified for the risk of spillover. The probability of the top event occurring was calculated to be 3. 12 10-7. Conclusions: According to the results of this study, tank overflow is one of the most important hazards in the loading arm section.

Today, the drawbacks of the hydrodesulfurization process have led to the development of new methods such as adsorptive desulfurization (ADS), extraction, oxidation, etc. Unlike the hydrodesulfurization method, ADS has the ability to remove resistant sulfur compounds such as DBT and its derivatives without the need for expensive and risky hydrogen and under low operating conditions (temperature and pressure). In this article, in addition to the comparison of modern desulfurization methods, among the solid adsorbents used in the ADS process, the performance of porous carbon adsorbents is investigated due to their unique characteristics such as high surface area and porosity, easy modification of physical-chemical properties and the cost is affordable and has been paid. Also, for a better understanding of the process, the effective process parameters, kinetics and thermodynamics and various adsorption mechanisms in the ADS process by carbon materials have been investigated. And finally, various methods of recovery of carbon adsorbents are introduced and the challenges of advancing the ADS process are mentioned.

Refineries, including the conversion industries, use oil and gas as row materials and their production processes could be so harmful to the environment if they could not manage the products detrimental effects. Nowadays these companies are working hard to minimize the environmental damages caused by their products, production processes, supply chain, distribution methods and etc. The first step in this way, is having access to the proper method to assess the products environmental impacts. In this paper a new method is presented to evaluate the refinery products degree of greenness. The developed model consists of influencing parameters on greenness degree, which are classified in a hierarchical structure. Due to the difficulties in defining an explicit function, fuzzy controllers are implemented to infer degree of greenness based on influencing parameters values. Effectiveness of the presented model is evaluated by assessing the greenness degree of Bandar Abbas refinery products and the results reflect good performance of the developed model.

Temperature overlapping is always considered in petroleum rectification. In this study, a mechanism is suggested to remove the temperature overlapping in distillation curve for rectification units which their feeds are liquefied petroleum. In this mechanism, firstly the unit is simulated and then is optimized by defining an objective function. Finally, operating conditions were determined without temperature overlapping in the distillation curve. Steps for defining the objective function are also presented. Optimization of a petroleum refinery by the presented mechanism shows considerable reduction in temperature overlapping of the distilled products and pushing them into appropriate operating range. Furthermore, applying the optimized conditions to the unit will be beneficial by 2958486 $/yr.

Refineries, including the conversion industries, use oil and gas as row materials and their production processes could be so harmful to the environment if they could not manage the products detrimental effects. Nowadays these companies are working hard to minimize the environmental damages caused by their products, production processes, supply chain, distribution methods and etc. The first step in this way, is having access to the proper method to assess the products environmental impacts. In this paper a new method is presented to evaluate the refinery products degree of greenness. The developed model consists of influencing parameters on greenness degree, which are classified in a hierarchical structure. Due to the difficulties in defining an explicit function, fuzzy controllers are implemented to infer degree of greenness based on influencing parameters values. Effectiveness of the presented model is evaluated by assessing the greenness degree of Bandar Abbas refinery products and the results reflect good performance of the developed model.

The oil refining industries are using a number of demulsifiers for dewatering and desalination of crude oil but experience has shown that universal demulsifiers can not be produced. Each kind of water in oil (W/O) emulsion requires specific by composition demulsifier. In practice, synergetic effect of the interaction between different types of demulsifiers is often sought. For dewatering the water in oil emulsion of crude oil from the Ural region, 16 kinds of demulsifiers were tested, named D1¸D16. With combinations of demulsifiers, the highest rate of emulsion drying was observed with mixture 1 (2.5 ppm of demulsifier D5 and 2.5 ppm of demulsifier D9). For the emulsion of water with diesel fraction boiling in the temperature range 180-360oC, mixture 1 at concentration of 20 ppm gave the optimal effect in breaking the emulsion. The results obtained from the experiments showed that the overdosing of demulsifier did not lead to optimal emulsion breaking and laboratory and industrial scale experiments should be carried out to break specific emulsion.