Sorption enhanced carbon dioxide hydrogenation to methanol: Process design and optimization

Process modelling and feasibility study of sorption-enhanced methanol synthesis

“…Therefore, a typical pressure swing adsorption (PSA) cycle is the most time-efficient regeneration scheme for the considered process. A detailed description of the complete PSA cycle consisting of pressurization, reaction, depressurization and regeneration steps was described previously [27]. Considering the axial profile of the loading of water on adsorbent in the reactor at the end of the reaction step, the flow of the gases during the depressurization and regeneration steps is arranged in the direction opposite to the flow of the gases during the pressurization and reaction steps.…”

“…Accounting for the in-situ removal of water, the readjusted values of the kinetic and adsorption constants were taken from our previous work [32] along with the parameters of the Langmuir adsorption isotherm used to evaluate the adsorbent equilibrium loading under the sorption-enhanced methanol synthesis conditions. While all the details of the dynamic reactor model are provided in our previous works [23,32,27,28], governing equations forming the basis of the model are also described in the Supplementary information.…”

“…Complete recirculation of the vapor phase from the high-pressure flash separation unit is considered, and the constant GHSV in the reactor is maintained by adjusting the make-up flowrate of the fresh H 2 /CO 2 mixture. A detailed description of the methodology employed for the recirculation modeling accounting for the residence time in the flash drum is provided in our previous work [23] along with the governing equations and boundary conditions forming the basis of the reactor model.…”

“…Based on the multi-objective optimization results [23], the process parameters and the overall cycle design were adjusted to comply with the target purity of 99.0 w-% for the blend methanol product after achieving the cyclic steady state. Particularly, reactor temperature, catalyst/adsorbent ratio, and GSHV for reaction and regeneration steps were varied to maximize the specific methanol production rate keeping the required product purity.…”

“…In our previous study [23], an experimentally validated dynamic model was developed for the investigation of the sorption-enhanced methanol synthesis process. The novelty of this model was in the re-adjustment of established kinetic parameters developed for steady-state methanol synthesis to take into account the kinetic effects of water sorption, leading to improved prediction of the dynamic sorption-enhanced reaction.…”