Measurement of Mass Transfer Coefficients of Natural Gas Mixture during Gas Hydrate Formation

In this study, mass transfer coefficients (MTC’s) of natural gas components during hydrate formation are reported. This work is based on the assumption that the transport of gas molecules from gas phase to aqueous phase is dominant among other resistances. Several experiments were conducted on a mixture of natural gas at different pressures and temperatures and the consumed gas was monitored and measured over time. The driving force is the difference between the solubility of hydrate former components at operating pressure and the corresponding equilibrium pressure. It was found that MTC is a function of pressure and temperature during hydrate growth stage. Consequently, an equation was proposed to calculate the mass transfer coefficient based on the experimental data

CFD Simulation of Dimethyl Ether Synthesis from Methanol in an Adiabatic Fixed-bed Reactor

A computational fluid dynamic (CFD) study of methanol (MeOH) to dimethyl ether (DME) process in an adiabatic fixed-bed reactor is presented. One of the methods of industrial DME production is the catalytic dehydration of MeOH. Kinetic model was derived based on Bercic rate. The parameters of this equation for a specific catalyst were tuned by solving a one-dimensional homogenous model using MATLAB optimization module. A two-dimensional CFD simulation of the reaction is demonstrated and considered as numerical experiments. A sensitivity analysis was run in order to find the effect of temperature, pressure, and WHSV on the reactor performance. Good agreement was achieved between bench experimental data and the model. The results show that the maximum conversion of reaction (about 85.03%) is obtained at WHSV=10 h-1 and T=563.15 K, whereas the inlet temperature has a greater effect on methanol conversion. Moreover, the effect of water in inlet feed on methanol conversion is quantitatively studied. It was concluded that the results obtained from CFD analysis give precise guidelines for further studies on the optimization of reactor performance