Abstract Abstract

Abstract Research subject: Propylene is one of the most prominent gases due to some valuable products and derivatives such as polymers, solvents, dyes, etc., which makes it one of the most important building blocks in the chemical industry. Due to the limitations of steam cracking and fluid catalytic cracking processes in terms of low selectivity, energy consumption, and significant CO₂ emission, these processes cannot fulfill the growing demand for propylene. In recent decades, the dehydrogenation of light alkanes to produce light olefins, especially propane dehydrogenation (PDH), has attracted much attention. Pt-Sn and CrOx catalysts, which are widely used in this process, have good dehydrogenation activity and selectivity; However, the limitations of price, deactivation, and environmental problems are serious and have led researchers to improve coking stability, sintering Pt catalysts, and find new and environmentally friendly catalysts.
Research approach: : One of the challenging issues in the PDH process is achieving
appropriate catalyst. Several solutions, including modification of the base and introduction of additives, have been proposed to enhance the catalytic performance overcome the problems, and increase the resistant stability of Pt, Cr catalysts. Understanding the structure-performance relationship of catalysts during the PDH reaction is essential to achieve innovation in new high-performance catalysts. This research aims to introduce the characteristics of the dehydrogenation reaction, the progress made in the development of the catalyst, and the existing challenges. This research provides a deep understanding of the reaction mechanism and its role in the development and future directions of the catalyst for practical and industrial development.
Main results: This study offers a detailed understanding of how the reaction mechanism works and its significance in the development and future directions of the catalyst for practical and industrial advancement.

Abstract Research subject: In the present study, a number of linear and long-chain branched copolyesters, poly (butylene succinate-co-ethylene terephthalate) (PBSET), were synthesized. Hence, effect of branching agent introduction was studied. Such a copolyesters, mostly aliphatic polyesters, may be applied in biomaterial fields. Adding aromatic section and branching agent have great effects on properties.
Research approach: All polyesters were synthesized via a two-step method: esterification and polycondensation. All samples were produced in a laboratory scale set-up. First, prepolymers of two monomers were produced, separately. Then, required amount of each prepolymer were poured in the reactor and catalyst and thermal stabilizer were added and polycondensation reaction was performed. Pentaerythritol (PER) and trimellitic anhydride (TMA) were used as branching agents during synthesis. Microstructure of the copolyesters were characterized by ATR-FTIR and ¹³CNMR. Crystallinity, using XRD, and mechanical properties were studied, too. Even small amount of branching agent has a great effect on properties. 0.4 mol% of PER and 0.4 and 0.6 mol% of TMA were incorporated.
Main results: Intrinsic viscosities of samples indicate that high molecular weight, about 38000 g/mol, were reached. ATR-FTIR spectra proves polyester synthesis. ¹³CNMR spectra shows incorporation of branching agent in polyester chain. Based on the XRD spectra, branching has no effect on the crystal type and type of crystal was unchanged. However, Crystallinity is decreased with branching. Mechanical properties are under serious effect of branching agent addition. It was observed that elongation at break and tensile strength were increased up to 400% and 200%, respectively. Hence, these branched copolyesters were synthesized and structure, crystallinity and mechanical properties were studied.

Abstract Iodide anion is found in some brine and wastewater. Iodide recovery from wastewater is beneficial from economic and environmental aspects. Discharge of iodide containing wastewater into surface water may lead to formation of some iodine containing species in drinking water sources. It is a treat for human health. In this study, iodide adsorption from wastewater )1000mg/l (using strongly basic anion exchange resins Amberlite IR400 Cl was investigated. Four common two-parameter models were used for description of isotherm adsorption data. Maximum static capacity of resin was obtained from Langmuir isotherm equation and it was 466.3mg/g. Iodide adsorption in various pH and presence of co-existing ions including SO₄^2- , NO₃^- and Cl^- was investigated too. The maximum obtained capacity was related to neutral pH. Kinetics study showed that the uptake of iodide ions was well described by the pseudo-second-order kinetics. Dynamic capacities of resin were investigated with column study. They were 434.2mg/g and 304.6mg/g for iodide adsorption from iodide solution and iodide solution in presence of co-contaminant ions (SO₄^2- , NO₃^- and Cl^- in concentration of 8mmol/l). The data from breakthrough curve was analyzed with common breakthrough models including Thomas, Dose-response and Yun-nelson models. Morphology of resins was investigated with SEM image and presence of iodide on resin was confirmed by EDS analysis and Raman spectra. The adsorption capacity of resin in comparison with the other adsorbents was considerable.

Abstract Research subject: Polypropylene (PP) is a thermoplastic polymer that is used in a wide range of applications, including films and sheets, blow molding, injection molding, food packaging, textiles, laboratory and medical equipment, pipes, industrial and construction applications, and the manufacture of automotive components. In the applications of this polymer, improving the surface of PP has been considered. One of the usual methods for improving the surface is the cold plasma method. Plasma is a chemically highly active environment where there are many ions and radicals. In this research, atmospheric pressure gliding discharge plasma was used to increase the hydrophobicity of PP and the surface and depth changes of PP were investigated.
Research approach: The depth and surface changes of PP were investigated by radiating the gliding discharge plasma to the PP polymer surface at the different times. FTIR and XRD tests were performed to investigate volume changes and FESEM investigated the surface changes. The hydrophobicity of PP was investigated by contact angle (CA) test and positron lifetime spectroscopy (PALS) was used to investigate shallow depth changes.
Main results: The results show that the applied cold plasma did not cause volumetric changes in PP, but caused surface changes and roughness. In this polymer, the contact angle has increased from 30.1 ± 0.1 to 34.4 ± 0.1 and the hydrophobicity of the surface has increased. Examining the changes in holes by PALS test shows that after plasma irradiation the volume of the holes increased from 217 ų to 222 ų and their intensity decreased. This is due to the heat of the plasma and the energy of its particles.:
The results show that the cold plasma caused surface and depth changes and the contact angle increased from 30.1 ± 0.1 to 34.4 ± 0.1 and the hydrophobicity of the surface increased.

Abstract Research topic:
Gas lift is an efficient artificial lift strategy, routinely used to overcome the low productivity of the wells. In this research, the possibility of using two gases, carbon dioxide and nitrogen instead of natural gas, in the gas lifting process is investigated and compared. To maximize oil production, the optimization of the allocation of the limited amount of gas between 10 wells in the Iranian offshore brown oil field is performed.
Research Method:
In this research, all the wells were modeled by PROSPER software. First, all 10 wells data of an Iranian offshore oil reservoir were collected. Secondly, their model has been built and after validation, a simulation of the artificial gas lift was performed using carbon dioxide and nitrogen gas separately, then, the Gas Lift Performance Curve (GLPC) of all the wells are fitted with the appropriate experimental model in MATLAB software. In the following, using Solver Excel, the allocation optimization with a limited amount of gas was performed using two different gases.
Main results:
According to the results obtained from the optimization, for a certain amount of available gas which is 15 MMSCFD, the total Oil production in the case of nitrogen gas injection is 3564 STBD more than carbon dioxide gas injection. Also, in all cases, due to the production potential capacity of well No. 8, the most amount of injected gas is allocated to it. The comparison of the two types of injected gas shows that the quantity of oil produced using nitrogen is 3424 and 3302 STBD (28 % and 24 %) greater than carbon dioxide gas when the gas is lowered to 12 and 9 MMSCFD, respectively.