آزاده میروکیلی

The current study highlights the significance of optimum recycle purge gas ratio (F) to methanol synthesis reactor calculated via a one dimensional modeling of process and also proposes an environmentally friendly process. Moreover, Differential Evolution (DE) method is applied to maximize methanol mole fraction. The purge gas of this process includes about 60% hydrogen, 20% carbon monoxide and carbon dioxide and 20% nitrogen and methane. Burning of such these gases is not economical and environmentally friendly process, thus recycling the purge gas is a reliable work. Although complete restoration of the purge gas is environmentally friendly, it is not an economical process. In order to prevent accumulation of inert gases such as nitrogen and methane, a purge gas line is attached to the recycling stream. In addition, a nitrogen purification unit has been proposed in the present study. Nitrogen is separated from the recycle gas stream by a novel metallic membrane; furthermore, nitrogen is converted to ammonia during the purification process. The increase in methanol production in Optimized Reactor Configuration (ORC) is 41% compared with the one in Industrial Configuration (IC). The optimum recycle ratio is 0.41 in ORC while this parameter is 2.19 in IC and zero in Fresh Feed Configuration (FFC). Simulation results show that Stoichiometry Number (SN) is reduced to 2.1 at the entrance of reactor; moreover, methanol production rate increases in ORC. Furthermore, the capability of ORC for producing ammonia is 305 mol/h. Enhancement in methanol and ammonia productions demonstrate the superiority of ORC to the previous configurations.