Intrinsic Reaction Kinetics of Higher Alcohol Synthesis from Synthesis Gas over a Sulfided Alkali-Promoted Co−Rh−Mo Trimetallic Catalyst Supported on Multiwalled Carbon Nanotubes (MWCNTs)

Abstract

A statistically designed set of experiments was run in a continuous downflow fixed-bed reactor to evaluate the intrinsic kinetics of the formation of methanol, higher alcohols, total hydrocarbon, and carbon dioxide from synthesis gas under a range of experimental conditions. To eliminate mass-transfer resistance, a multiwalled carbon nanotube (MWCNT)-supported K-promoted trimetallic sulfided Co−Rh−Mo catalyst was used in the particle size range of 147−210 μm. To predict the reaction rate for higher alcohol synthesis, the power law model was used for the reaction between CO and H2 on the catalyst surface. The operating conditions, such as reactor temperature (T), pressure (P), gas hourly space velocity (GHSV), and H2/CO molar ratio, were varied in the ranges of 275−350 °C, 800−1400 psig (5.52−9.65 MPa), 2.4−4.2 m3 standard temperature and pressure (STP) (kg of catalyst)−1 h−1, and 0.5−2.0, respectively. The data of this study are well-fitted by the power law model. The activation energies of ethanol and higher alcohols obtained over Co−Rh−Mo−K/MWCNT were low compared to those values reported in the literature.