The Spheripol process is one of the most widely used technologies in the world for the production of polypropylene (PP). The geometry of the Reactor is such that the use of ideal Reactors alone causes an error in the simulation results. Therefore, in this research, we have tried to combine the ideal Reactors modules in Aspen Plus. v11 to get the most accurate results. In order to calculate the volume of the ideal Reactor, we used the concept of «required length for fully developed flow» and considered the inlets, outlet, and pump of the Reactor as a continuously stirred tank Reactor (CSTR) while the other part of the Reactor considered as plug flow Reactor (PFR). We also used three different kinetic constants reported by three different research groups and compared the result with the production plant data. Due to the importance of the thermodynamic model for the prediction of phase behavior, we used the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state that was used by previous authors. The results are validated with the production plant data and previous articles. Also, the effect of methanol as a catalyst poison is investigated.

The exaggerated release of industrial wastes especially those containing phenol into the environment led to the contamination of both surface and groundwater supplies. In the present work a synergistic and combined system technique between three operations, adsorption of phenol via (rice husk or granular activated carbon GAC as adsorbents) together with stripping by airflow and advance oxidation via hydrogen peroxide as the oxidation agent, to evaluate the possibility of using a proposed new design for internal airlift Loop Reactor for removing the phenol from wastewater. The experiments were set up in a cylindrical Perspex column consisting of a transparent outer column having a 15 cm inside diameter and 150 cm height that included an internal draught tube of 7. 5 cm and extending vertically to 120 cm top contains a bed having a dimension (7. 5 x 30 cm) filled with adsorbent materials (rice husk, granular activated carbon GAC) and a volume capacity 25 liters. The experiments were conducted under the influence of both of the following variables air flow rate (2-20) (L/min), treatment time (5-60 min), the molar ratio of hydrogen peroxide to phenol, (1: 10, 1: 15, and 1: 20)). The results showed the success of the proposed design with obtaining a removal efficiency (83%), ( 81%)when using GAC and the rice husk as adsorbent materials respectively, with a minimum remediation time 60 minutes, airflow rate of 18 L/min, and molar ratio(20) hydrogen peroxide to phenol. This study demonstrated that the proposed synergistic system could be utilized for the remediation of contaminated aqueous systems.

An 1D hydrodynamic model has been simulation and developed for gas hold-up and liquid circulation velocity prediction in air-lift Reactors. model is based on momentum balance equations and has been adjusted to experimental data collected on a pilot plant Reactor equipped with two types of gas distributors and using water as the liquid phase.The model equations described previously constitute a set of non-linear equations which are solved by an iterative procedure (v.b) (c plus). This model has also been combined with mass transfer and the kinetics of a chemical reaction to yield a complete model of the performance of a Reactor.

An airlift Reactor with the external Loop (EXL ALFR) is a widely used modified version of a Bubble Column Reactor (BCR). An EXL ALFR can also be used for a three-phase system with the solid phase in a packed or fluidized form. An EXL ALFR provides design flexibility for conventional chemical reactions as well as biological reactions. Shear is an important factor for the Reactors handling immobilized enzymes. In the current investigation, the effect of the design variables, like gas hold-up, the velocity of circulating liquid, and the distribution of bubble dimension, was compared for an EXL ALFR and an external Loop airlift Reactor with a packed bed (EXL ALFR-PB). Particle Image Velocimetry (PIV) was employed for the liquid axial velocity in the downcomer of the Reactors, and the computational fluid dynamic with the Population Balance Model (CFD-PBM) was employed. The minimum percentage of errors of 2.3% and 1.2% and the maximum of 4.2% and 3.4% were obtained for the experimental and predicted values of gas hold-up in the EXL ALFR and EXL ALFR-PB, respectively. For the velocity of the circulating liquid, the predicted and experimental values of their minimum percentage error were 1.1% and 0.5% and a maximum of 4.3% and 4.5% in EXL ALFR and EXL ALFR-PB, respectively.  Also, the pressure drops calculated from the Ergun equation and CFD simulation had a 0 to 4% difference, indicating good agreement.

In order to enhance applicability of Tehran Research Reactor (TRR) for irradiation test of nuclear fuels and materials and considering TRR potential to provide required neutronic and thermal-hydraulic conditions for irradiation tests on domestic nuclear fuel samples, TRR fuel test Loop is designed and fabricated. This test Loop with 10 bar nominal pressure and 20m3/h nominal volumetric flow rate is designed to simulate thermal-hydraulic conditions of the Reactor core in which, the fuels will be used. In this research, safety assessment of the consequences of loss of flow accident in the fuel test Loop due to primary pump breakdown is performed and the functions of safety systems to provide continuous cooling for the test fuel samples and also to mitigate any undesirable consequences of this accident are evaluated. In this regard, the probable scenarios are simulated using a RELAP5 model and the ability of the safety features of the Loop to prevent any damage to the test fuel rods is evaluated. The results reveal that safety systems of test Loop can provide safe condition during the accident in which the meat and clad temperatures of test fuels remain within the permissible limits.

Recent studies have shown that a combination of coal fly ash (FA) and Al(OH)3 can be used to treat neutral mine drainage (NMD) and reduce sulphate concentration to within South African drinking water quality levels, Class II (400-600 mg/L). The shortcomings of this method were the large amounts of FA required to raise the pH to greater than 11 (3:1 liquid-to-solid ratio) so that Al (OH)3can be added to facilitate removal of sulphate ions through ettringite precipitation. This requires large silos to store FA, making up-scaling of this treatment technology using normal mixing methods to be unrealistic. In the current study, a jet Loop Reactor was used to reduce the amount of FA needed to increase the pH to greater than 11. The pH was raised to greater than 11 by mixing 0.25 % of lime (w/v ratio) and 13 kg of coal FA with 80 L of NMD in a jet Loop Reactor. After the pH of the mixture was above 11, amorphous Al(OH)3 (83.2 g) was added to the mixture. This resulted in the sulphate concentration decreasing to less than 500 mg/L. Bench-scale studies using 0.25 % (w/v) of lime and 6:1 coal mine water to FA ratio could not reduce the sulphate concentration to below 500 mg/L. Therefore, the impingement and cavitation mixing techniques that happen in a jet Loop Reactor played an important role in enhancing sulphate removal.

Glucose isomerization to fructose by immobilized glucose isomerase as an example of solid-liquid enzyme reaction has been studied in a down flow jet Loop Reactor (DJR). Conversion of glucose to fructose has been measured and compared with that formed in a batch Reactor. The performance capability of the DJR was observed to be higher than that of the conventional Reactors. The optimum operating conditions of the reaction system have been also determined using the Taguchi experimental design method. The effects of enzyme loading, draft tube diameter, position of nozzle inside the draft tube, and gas and liquid flow rates on glucose conversion have been considered. Analysis of the results revealed that the draft tube diameter has the highest and the ratio of the liquid circulation rate to the gas flow rate has the least effects on the conversion of glucose. It was found that the experimental data could be correlated favorably with a mofidied structure of the michalis-menten model consisting of two transition complexes.