مجله فرآیند نو
پیاپی 74 (تابستان 1400)

The presence of water in the oil often leads to problems reported in the literature from pressure flow limitations, reduced production, pipeline corrosion, pump malfunctions, poisoning of downstream catalysts in catalyst refineries, and other problems related to production equipment and distillation column. In this study, a coated filter with graphitic nitride carbon nanosheets (g-C3N4) was prepared and proposed as an alternative to demulcifiers to separate water from oil before entering the petroleum refinery. For this purpose, mesopore graphitic nitride carbon nanosheets are synthesized by thermal polycondensation method using hard-template approach and coated on the surface of stainless steel mesh using spray gun. The surface of the g-C3N4 coated mesh showed the hydrophilic/underwater superoleophobic wettability properties. The results of water-oil separation using the prepared filter showed that water permeated through the filter with a flux of 2200 L.m-2.h-1, while oil does not pass and remains on top of the filter with the separation efficiency more than 99%. The durability of the filter for water and oil separation was investigated and the results showed that the separation efficiency and flux after 25 cycles of water-oil separation have changed slightly.

New Schiff base (HBDP) has been investigated as inhibitor for corrosion of steel in the acidic environment. For this purpose; potentiodynamic polarization, AC impedance measurements, were utilized. Polarization curves reveal that the compounds are mixed type inhibitor and inhibition efficiency increases with increasing concentration of compounds. Further, the (HBDP), displayed the best inhibiting characteristics for this system, with a maximum IE of approximately 59% having added only 0.8mg/L. The compound obeyed the Langmuir isotherm. At the end, the surface of the pieces was examined by optical microscopy.

Hydrogenation of unsaturated compounds is of great interest due to the requirement of environmental laws to reduce their destructive effects on the health of humans and other organisms and on the other hand in the production of valuable chemicals. In this research, a series of heterogeneous catalysts, including nickel loaded with different types of catalytic supports by wet-impregnation method have been prepared and used for BTX hydrogenation (as a model) at 150°C. The physicochemical and structural properties of the catalysts were investigated by nitrogen adsorption and desorption methods, X-ray diffraction and scanning electron microscopy. In the final stage, the activity of the catalysts was also evaluated in the hydrogenation of benzene from the platformate feed at 150 °C. The results of comparing the performance of catalysts using two feeds are as follows: Ni/AC-FSM-16 catalyst has a very acceptable performance using BTX feed and Ni/AlMCF-13X catalyst for benzene removal from the platformate performed best.

This research, presents control structure design using non-minimal state space proportional-integral plus (PIP-NMSS). The system identified by RIVID method using SIMULINK of MATLAB by applying CAPTAIN Toolbox in order to achieve system model. The multi input-multi output (MIMO) control structure developed for 8×8 square state system to keep side products quality. The energy cost optimization was done by defining of energy consumption as objective function. The results show that inlet vapor to main column has been reduced by 19.8%, vapor inlet of gasoil stripper column has been reduced by 10.22%, heat duty of naphtha stripper column has been reduced by 3.83% and heat duty of kerosene stripper column has been reduced by 3.41%, while 0.135% increase observed in furnace heat duty. Based on the results energy cost has been reduced by %8.5, whilst kept quality products.

Structured packings with large specific area are widely used in mass transfer processes such as distillation. Effective interfacial area is the key parameter in determination of mass transfer performance, and differs from packing specific area. In present work, different  models for predicting effective interfacial area in structured packings such as Wang, Gualito, Olujic and Brunazzi were presented and accuracy of the models were compared with experimental data of  Mellapak 250Y with respect to the pressure and surface tension of system, in terms of gas and Liquid Loads. Predictive values of Wang and Gualito models are better than others by changing pressure. The mean absolute relative error (MARE) for these models are 31% and 44%, none of these models were recommended for predicting effective interfacial area. Respectively. Brunazzi and Olujic models showed the lowest deviation from experimental data which were 8% and 7%, respectively. The results of this work could be used as a guide to select the best models available for effective interfacial area prediction, and to direct future research in this area.

A two-dimensional hydrodynamic simulation of two-phase flow in a rotating drum under rolling conditions was examined in this study. The Eulerian-Eulerian multi-phase approach was utilized in this study to model the gas-solid system in a rotating drum, combined with the kinetic theory of granular flow. The results of these simulation was verified with experimental data was reported with Santos et al. (2015) which indicates that the results are consistent with experimental work. In this study impact of restitution coefficient on active layer thickness was investigated. For this purpose the restitution value set to different values (0.85, 0.9, 0.92, and 0.95) and their effect on the thickness of active layer on the rotating drum was examined. The thickness of the active layer was increased by raising the coefficient of restitution from 0.85 to 0.95, which, given that the majority of mixing occurs in rotating beds, can demonstrate an improvement in the degree of mixing in rotating beds with the results.