نشریه مهندسی گاز ایران
پیاپی 10 (اسفند 1398)

To improve the basic indexes of the hydrate formation process, , a proposed hybrid structure was used in this study, and a surface behavior engineering has been implemented to synthesize and select the components of it. The main agent of this structure is SDBS, a surfactant which has been selected as the driving factor for the dissolution stage. In this structure, zinc metal nanoparticles were stabilized to increase the efficiency of the hydrate growth stage and the polystyrene has been layered to provide an ideal and flexible nanoparticle and control the foam formation. The polymer layer, while capable of significantly reducing the amount of foam formation and decreasing the instability of the system during gas decomposition, provides a bridge between the carboxyl functional groups for bonding the zinc nanoparticles to the surfactant. Thus, polymer layer for surfactants makes them susceptible to industrial applications in the storage and especially release of hydrate from the gas. Experimental evidences also suggest that using a fluid containing a low concentration of the proposed composite structure can reduce the hydrate formation time by up to a quarter, and also double the volume of gas storage. These results are very attractive to use this engineered structure in industrial scale and its quantities are suggested.

One of the reactors used in the process of converting the natural gas into liquid fuel (GTL)is the Slurry Bubble Column Reactor (SBCR). Despite the many advantages of SBCR, it is difficult to design and scale up. Given the complex phenomena in the reactor and experiences acquired by the authors, in this paper a method is proposed in the form of an algorithm to design this reactor type. The proposed method was used for designing a reactor with a capacity of 1000 barrels per day is similar to that in the Petro - SA company of South Africa. The obtained dimensions for the reactor using the proposed method were in good agreement with the size of the reactor at operation. According to the results, the validated design method in this study can be used to design bubble column reactors with good accuracy.

Natural gas consists of various hydrocarbons, all of which have their own economic values. Ethane recovery provides ethane, which is one of the most important petrochemical feedstocks. In this study, simulation and optimization of the ethane recovery process in Bandar Imam Petrochemical in Iran was investigated. Simulation of the entire plant was carried out using the HYSYS (V.10) simulator, and the Peng-Robinson equation of state was used to calculate the thermodynamic properties. Using process flow diagram data, the accuracy of simulation was examined. At first, performance of the plant was investigated, then two improved configurations for the plant were examined. Results show that the plant performance must be improved by feeding back the additional cold reflux bypassing the top stream of demethanizer tower through heat exchanger (first configuration) or by compressing the top products of demethanizer tower and passing it through Joule- Thomson valve (second configuration). The first configuration increased ethane recovery to 96.55%, which was due to 3.67% increase of reflux flowrate; the second one enhanced ethane recovery to 99.76%, which was due to 24.58% increase of reflux flowrate. Economic analysis proved that new configurations are cost-efficient.

Naturally fractured reservoir account for 20% of world's oil reserves, in these reservoirs conductivity is mostly in the fracture network while the oil is mostly in the matrix and after primary recovery most of oil remains in the reservoir. Most of secondary or tertiary recovery methods such as water injection or gas injection are not efficient in fractured reservoirs. One of the remedy methods to control and improve volumetric sweep efficiency is foam injection. Foam in porous media is a dispersed gaseous phase within a continuous aqueous phase comprised mainly of thin films known as lamellae. The lamellae are stabilized by adsorption of surfactant at the gas/liquid interfaces. In the paper, experiments were performed to study the pertinent oil displacement mechanisms during gas and foam injection in a transparent fractured porous medium. Transparent material such as glass was used to construct micro models and to study various aspects of fluid displacement at pore scale. By using micro models, the displacement of the fluids can be observed and investigated in terms of micro-geometry and physical characteristics of the presented liquids, gases and solids. The classification of foams in based on their bubble size and gas fraction. The strength of foam is measured by the magnitude of the pressure drop that is generated along the medium. To create a large pressure drop very strong foams, and therefore very small bubbles, are required. Low productivity of gas injection in fractured reservoir leads to use foam instead of gas in order to increase resistance of fracture corridor against the injected fluid and to better control to mobility of gas.

Syngas, a mixture of hydrogen and carbon monoxide, is used as a valuable intermediate gas in important processes such as methanol, ethanol, ammonia, Fischer-Tropsch Synthesis as well as de-sulfurization units. Conventional industrial processes to produce syngas, such as steam reforming, demand high investments and are energy-consuming. Meanwhile, partial oxidation is an alternative method of syngas production with the advantage of lower H2/CO ratio. In the current work, a pilot scale syngas production by partial oxidation in a ceramic porous media is presented. The results obtained from the pilot show that a syngas with H2/CO ratio from 1.14 to 1.47 is produced. The product has lower carbon content than that of a reactor with a common burner. The remained methane, water and CO2 could be removed in the purification unit. According to the observation, when the flame is located upward in the burner, the final product is free of soot.

In this research, the simulation of air separation unit of lorestan petrochemicals was carried out using Aspen Hysys software and by selecting the Ping-Robinson thermodynamic model. In the following, comparing the simulation results of the unit with the actual data, a slight error of less than 0.7% in simulation was revealed. In addition, the energy optimization of the unit was accomplished by adding two process heat exchangers with a surface of 1.098 and 5.819 m2, respectively, instead of using the heat exchanger 901and before the entry of air into the Plant Air reservoir, which resulted in energy savings due to the elimination of the heat exchanger 901 in the new design. Moreover, in the new design , due to using the process converter, we were able to reduce the amount of water drained from the air into the Plant Air reservoir from 32.8 kg/hr to 38 kg/hr, both in terms of energy consumption and safety. The process is very important in cold weathers, especially in cold regions. In addition to the unit's optimization, the economic calculations waer carried out, in which the return on investment for the correction plan was estimated to be two months, which would result in a profit of $97975.12 per year.

The contract for production participation is one of the major deals in the world oil industry. In the contract for the participation in the production of the foreign oil company, it has entered into a contract with the public sector of the host country and will take over the risk of oil operations If the contractor does not succeed in oil operations, he must abandon the area and not be eligible for his costs, but if he succeeds in contracting for the cost and risk he has incurred, he will be entitled to a share Despite the desirability of this kind of contract in many oil-rich countries, the deal is not particularly acceptable due to legal barriers. Accordingly, the present article seeks to review the legal status of this agreement in Iran and identify legal barriersof the oil produced in the name of oil.