Determination of the Optimum Operating Conditions for Integrated Methanol and Ethanol Plant from Natural Gas Reactors

Methanol and ethanol can be produced from many kinds of feedstock. One of the most preferred methods to synthesize methanol is from natural gas, which is reformed to form synthesis gas (syngas) and converted by a catalyst to form methanol. Conversely, ethanol production mostly comes from biomass, which competes with human food fulfilment. Several pieces of literature conduct syngas transformation to ethanol to solve this problem. However, the experiment is conducted on a lab scale or pilot scale. Before the technology can be mass-produced on a plant scale, we must determine the most suitable operating condition for the reactor to escalate the reactor's productivity. This study is aimed to determine the optimal operating condition for the integrated methanol and ethanol plant, which is the reactors. The software used for the study is Aspen Plus V12.1. The independent variables for all the reactors in this study are the pressure (P) and the temperature (T). We add the feed molar flow ratio as the independent variable for the Steam Methane Reforming (SMR) and the ethanol synthesis reactor. The dependent variable that will be used for the determination of the optimal operating condition of the reactors is the reactant conversion and the product yield. The data validation between the experimental data conducted by other authors and the process modeling result is in good agreement with less than 6% of error for all three reactors. After performing the process simulation and sensitivity analysis to determine the optimal operating condition for the reactors, it is found that the optimal operating condition for the reactors is as follows: (1) SMR reactor: 25 bar pressure, 1,223 K temperature, feed molar flow ratio (H2O/CH4 ratio) of 3, (2) methanol synthesis reactor: 100 bar pressure and 503 K temperature, and (3) ethanol synthesis reactor:110 bar pressure, 583 K temperature, and feed molar flow ratio (H2/CO ratio) of 0.75.