نشریه فناوری های نوین در سیستم های انرژی
سال دوم شماره 1 (پیاپی 201، بهار 1395)

Contamination of water sources with the heavy metals such as zinc, copper, lead and cadmium is a serious environmental problem. Zinc ion has undesirable effects on plants and animals at concentrations higher than the threshold limit. Amongst traditional methods of heavy metals removal, the biological removal is considered as a low cost and environmentally friendly method. In this study, the removal of zinc ions from aqueous solutions by algae is estimated as a function of pH and the ratio of initial zinc ions to algae. Genetic programming is used to construct an empirical relation to correlate the removal of zinc ions to pH and the ratio of initial concentration of zinc ions to the concentration of algae. The experimental data used in this study, consists of 122 data, including the removal of zinc ions, pH and the concentrations of zinc ions and algae. About 70% of the data was used to calculate the empirical equation and the remaining 30% was used for verification of the equation. The average absolute relative deviation obtained for 122 data points is 4.08%, which verifies the accuracy of the correlation in the estimation of the removal of zinc ions from aqueous solutions.

The increase in producing greenhouse gases has become a serious phenomenon for industry as well as the environment. Thus, using alternative fuels such as biological fuels has been highly regarded in recent years for the purpose of reduction of greenhouse gases. In this paper different thermo dynamical equations have been evaluated in order to calculate the density of 1-butanol+cyclohexane hybrid fuel in the pressure condition of the injector of the diesel engine. The pressure ranges between 30 to 70 MPa in the mentioned condition. To the point that there is not enough appropriate experimental data at pressures higher than 30 MPa, it is essential to choose the most accurate equation for calculating the density of the hybrid fuel and numerical simulation. (There are a few experimental data in the range of 30-100 MPa). Comparing the results with experimental data at pressures up to 70 MPa, BWR-LS Virial EOS (Equation of State) has the error of less than 1% for this hybrid fuel. PRWS cubic EOS has more accurate results at 0.8 concentration of 1-butanol (error=0.32%) than BWR-LS (error=0.76%) in calculation of density of the hybrid fuel. As a conclusion, we suggest using BWR-LS Virial EOS for precise calculation of the density of 1-butanol+cyclohexane hybrid fuel in AVL FIRE simulation software.

Due to the increment of studies about greenhouse gasses and their effect on climate change we attempted to simulate carbon dioxide capture process via aspen plus V8.8. Our simulation implemented by rate-based model and the rest of conditions such as solvent, columns and packing were assumed same as pilot plant data. We used a novel model which proposed earlier by AspenTech® referred to previous studies we select ELEC-NRTL thermo dynamic model which had a great feedback for prediction of electrolyte system’s behavior in literatures. we validated our results with previous work and experimental data results were acceptable with accuracy of 7% and due to the analogy to the actual column our model had a better result such as CO2 more purity in second column effluent and better CO2 capture up to 6.5%. Also our model converged precisely by makeup stream which had lower MEA consumption up to 35%.

This work presents a laboratory phase behavior study in a Sodium Stearate/ brine/ oil system. Phase behavior observations of the micro emulsion are reported both quantitative and qualitative. The experiments were designed to investigate the emulsion stability, oil/ water interfacial tension (IFT) and the viscosity of the emulsion phase in a wide range of temperature (25-60o C), water-to-oil ratio (0.2 to 5.0), salinity (10 to 200,000 ppm), and surfactant concentration. The range of variables was selected as what typically occurs during a chemical enhanced oil recovery (EOR) process. PH variations were examined by changing that of the system from 1 to 11, using different acid and alkaline. As the pH increases, the stability of the emulsion phase increases as well as the emulsion phase thickness. Besides, the viscosity of the emulsion phase was also monitored qualitatively at different temperatures. Moreover, using long chain alkanes as the oil phase, confirms the capability of the surfactant for chemical EOR process.

In this paper mullite and mullite-alumina microfiltration (MF) membranes were fabricated by extrusion and sintering method. This membranes were used in novel MF-coagulation-PAC hybrid process for synthetic oily wastewater treatment. Four type of coagulant agent were used. Aluminium chloride 100 ppm, aluminium sulfate 50ppm, ferrous chloride 200 ppm and ferrous sulfate 50 ppm. In all experiments, equal concentration of each coagulant with calcium hydroxide in form of calcium hydroxide (Ca(OH)2) was added to the synthetic oily wastewater in the MF-coagulant-PAC hybrid process. Powdered activated carbon (PAC) was used as adsorbent agent with 200ppm in all tests. All tests under optimum condition (CFV=1.5 m/s, TMP= 3bar, T=35 C) were done. Permeate flux (PF) for each coagulant agent were reported. Results showed that by using ferrous salts PF is higher than aluminium salts for both mullite and mullite-alumina membranes.

The aim of this study was to investigate the effect of diluents in the NOx emissions and qualitative study of the effect of these changes on the gas burner flame. For this purpose, the effect of dilution was investigated on the combustion process in a laboratory scale gas burner by using various fuels, including natural gas, butane and propane. The nitrogen gas was used for dilution. The results showed that dilution of the fuel significantly reduced the amount of NOx production and this amount of reduction was 30 to 57 percent and depends on the type of fuel and the dilution. On the basis of the results and experimental analysis, the type of the fuel and the amount of dilution are identified as effective parameters on NOx emissions but the impact of fuel type is higher.