Abstract
Synthesis gas (syngas), mainly constituted by carbon monoxide (CO) and hydrogen gas (H2), is produced mostly through biomass gasification and methane reforming. In the last decade, the thermochemical route to produce ethanol and higher alcohols from syngas has been gaining space as a possible route to produce synthetic fuels and additives. This kind of process presents a series of advantages as: short-time reaction, abundant and lower-price feedstocks, the use of lignin and the almost complete conversion of syngas, having the potential to exceed ethanol production by fermentative route. Aiming to produce ethanol through thermochemical route, a singular process (a small-scale plant with capacity to process 100 kmol/h of syngas) was proposed for a first evaluation using the commercial simulator ASPEN Plus v7.3. Four different Rh-based catalysts were tested in the process (RhFe, RhLa, RhLaV, and RhLaFeV), trying to take advantage of the characteristics of Rh-based catalysts as high ethanol selectivity and hydrocarbons production. The process design took into account the reactor selectivity and conversion. Through sensitivity analysis, the downstream process were configured searching for the best possible design of separation steps, making possible to obtain ethanol (>99 % wt.), methanol (>90 % wt.), Liquified Petroleum Gas (LPG, mixture of C2H6, C3H8 and C4H10, > 99 % wt.) and pentane (>95% wt.).