APPLIED RESEARCH IN CHEMICAL POLYMER ENGINEERING
Year:2019 | Volume:3 | Issue:2|Papers Count:6

Research subject: Propane and butane that are the contents of LPG are separated from natural gas in the unit 107 of 5th refinery of South Pars Gas Company (SPGC) and then they are purified from mercaptans in units 114 and 115 respectively. The concentration of methyl mercaptan and ethyl mercaptan in the propane stream are 551 and 46ppm, respectively, and the concentration of these components in butane stream are 1218 ppm and %0. 8, respectively. In order to remove mercaptans from butane and propane, aqueous solution of sodium hydroxide with 15 to %20 wt. is used for the scrubbing. Research approach: In this research, using the Petro-SIM software, which is a particular simulator for oil and gas industries, the units, 113 114, and 115 of 5th refinery of SPGC are simulated. Main results: The results of the simulation are compared with the data of both experimental data and design documents. The maximum error between DSO concentration of the simulation results and design data was %7 and it is showed that they are goodly match. Then, using the software optimizer the operating parameters is optimized. The objective function for optimization was the mole fraction of methyland ethyl-mercaptan in all of products. The minimization of objective function is the main goal of optimization. The optimization results show that by increasing the extraction temperature in the unit of 115 up to 46 ° C, the concentration of mercaptan in the products can be reduced. The other independent parameters do not affect the final result of the process.

Research subject: In this study the scope of application of polymer materials in the preparation of drilling fluids is examined. Therefore, various blends of wheat starch and copolymer of sulfonated polyacrylamide were prepared and their rheological properties were investigated. Research approach: The rheology and compatibility behavior of samples under different salinity and aging conditions were evaluated. Main results: The rheological behavior of starch-polyacrylamide blends in tap water and saturated brine water showed that the viscosity of the samples increased with increasing concentration of polyacrylamide copolymer in the both media. However, starchpolyacrylamide blends in saturated brine had less viscosity than tap water. It was observed that in both tap water and saturated salt water conditions after 4 hours of aging at 90 ° C, the viscosity of most samples increased. Comparison of the curves for empirical viscosity data and prediction of the mixing rule showed that in both of tap water and saturated salt water, positive deviation from the mixing rule is observed, which indicates the compatibility between the blend components. By performing the aging process, although positive deviation was still observed, this positive deviation slightly decreased, which means the negative effect of aging on the compatibility of the starch-copolymer of sulfonated polyacrylamide blend. In conclusion, the results of this study showed that the blend of starch-sulfonated polyacrylamide copolymer is compatible at high temperature (90 ° C) and saturated NaCl salt water. Moreover, in some samples, this compatibility exists even after aging.

Research subject: Water flooding is one of the most common improved oil recovery methods in the world. High residual oil saturation at the end of this method is due to low macroscopic sweep efficiency and viscous fingering phenomena. It can be improved by change the mobility control during polymer solution injection. Research approach: In this study, by synthesis of silica/polyacrylamide nanocomposite, the effect of it on mobility ratio, interfacial tension, viscosity of chemical solutions, and reservoir rock wettability was investigated. Morever, the performance of polymer solution in high salinity water was studied by using nano particles. In addition, the characterization of the synthesized nanocomposite was performed by FTIR, SEM, and TGA tests. Also, in this study, the interfacial tension between reservoir oil and chemical solutions, contact angel in order to measure the reservoir rock wettability, zeta potential, and viscosity of chemical solutions were performed to investigate the impact of injected water on rock and fluid properties. The concentration of nanocomposite solutions were considered 2000, 1000, and 5000 ppm during the experimental measurements. Main results: The zeta potential results show that the stability of polymer solution was enhanced in presence of nano particles in high salinity water condition. Also, the lowest interfacial tension was obtained for polyacrylamide nanocomposite contained 1 percent nano silica (18. 34 mN. m), and the most tendency to water wet conditions was provided for this concentration. In addition to, 1 percent nano silica/polyacrylamide nanocomposite has the best performance on formation water viscosity and improved the mobility ratio to 1. 07, which it can increase the oil recovery.

Research subject: Energy is an integral part of human life and from the beginning of history, mankind is looking for a way to control it to provide the basic needs. One of the available energy sources is fossil energy that has been considered due to the huge amount of energy. Microbial fuel cell is a bioreactor which converts the chemical energy stored in chemical bonds of the organic compounds to electrical energy through the catalytic reactions. Research approach: In this paper, two types of classical PI and MPC controller are used to investigate the voltage control of a two chamber microbial fuel cell using the model which has been presented by Esfandyari et al. [1, 2]. Considering the features of the proposed model, it can be used to optimize and control the MFC in continuous and batch modes. For this purpose, a classical PI controller based on internal model and MPC controller was designed and implemented. Based on the designed controllers, the adjustment of substrate input flow rate was implemented considering the distribution such as substrate input concentration or the uncertainty of the process model parameter such as Ks and rmax. Main results: For to control the output voltage, step change of 5 units was made in setpoint (inlet flowrate to anode chamber). The values of absolute integral error, rise time and overshoot for the classical PI controller were 3. 75, 13. 159, and 0. 091, respectively, while these values were 0. 035, 11. 908, and 0. 142, respectively for the MPC controller. Considering the achieved data, it can be concluded MPC controller performed better than the classic PI controller.

Research subject: The use of genetic engineering tools to produce industrial strains, especially from non-model microorganisms such as cyanobacteria, is always subject to limitations. Research approach: In this research, a system-oriented method was used to design a culture medium instead of strain designing and its ability to increase ethanol production by Synechocystis sp. PCC 6803 was experimentally evaluated. In this method, compounds are added to the medium to regulate the activity of target enzymes not for the purpose of being consumed by the cells, and thus, the designed culture medium eliminates the intracellular constraints on the production. A metabolic model was used to determine the minimum level of ethanol production and to identify genes that increase or decrease of their expression increase this minimum level. Then, regulators of the enzyme expressed by the target genes were extracted from the Brenda database and their effect on the production was evaluated experimentally and design of experiment was performed to optimize the concentration of the selected compounds. Main results: Among the compounds identified, two inhibitors (salicylic acid and mercuric chloride) and one activator (pyruvate) were selected to be added to the medium and their concentration was optimized using the central composite design method. The proposed regulatory medium increased the production of ethanol from 352 to 1116 mg/l, indicating the effectiveness of the added regulatory compounds on the cyanobacteria metabolism. The proposed systemoriented method can be used to design medium culture for other important bio-products such as recombinant proteins.

Research subject: In the last few years, the application of biotechnology for cleaning-up heavy metal-bearing solution is rapidly growing, but industrial usage of this category, however, needs to be more investigated. Research approach: In current research, Pseudomonas putida– Chitosan hybrid biosorbent capability for U(VI) biosorption in fixed– bed column was investigated. Main results: The results showed that increase in inlet concentration from 50 to 200 mg/L increased the biosorption capacity from 188. 75 to 429. 28 mg/g. In the column system, the sorption capacity was higher than that of the batch system because fixed-bed column make best use of the inlet concentration difference as sorption driving force. Decrease in inlet flow rate through increase in the residence time for better diffusion or interaction as well as greater access to binding sites for uranium ions caused an improvement in column performance. Decline in the biosorption capacity due to increase in the inlet flow rate demonstrated that intraparticle diffusion was the rate-controlling step. With decreasing in the sorbent particle size from 1. 5 to 1 mm, a significant increase in the biosorption capacity from 179. 02 to 296. 87 mg/g was achieved. FTIR and potentiometric titration confirmed that while – NH+3 was the dominant functional group in the chitosan, – NH+3, – NH3, – OH, – COOH were responsible for the hybrid biosorbent. In conclusion, the present study indicated that Pseudomonas putida – Chitosan could be a suitable biosorbent for U(VI) biosorption from aqueous solution in the continuous system.