Kinetic Estimation of Fischer-Tropsch Synthesis using Biogas-derived Feedstocks over Ni/Al2O3 Catalyst

Abstract

Abstract In this study, the kinetics of the Fischer-Tropsch process (also known as FTS) were investigated using feedstocks produced from biogas. For the kinetic testing, a differential fixed-bed reactor was utilized to operate the Ni/Al2O3 catalyst produced using precipitation procedures. Experiments were carried out with a variety of settings for the working circumstances, such as reaction temperatures ranging from 543 to 563 °K, H2:CO ratios ranging from 0.5 to 3, a pressure of 3.0 megapascals, with (GHSV) a gas hourly space velocity of 3500 (1/h). The reaction kinetics within this range of conditions can be modelled in a precise and accurate way thanks to the derived kinetic parameters. The FT reaction hypothesized mechanism uses the Langmuir-Hinshelwood-Hougen-Watson theory, which predicts that carbon monoxide and hydrogen will have an adsorption behaviour. The kinetic data obtained in this investigation were effectively modelled using a straightforward equation, which is as follows: \({- r}_{CO}=\frac{k.{P}_{CO}^{n}.{P}_{{H}_{2}}^{m}}{{(1+K.({a}_{CO}.{P}_{CO}^{n}+{a}_{{H}_{2}}.{P}_{{H}_{2}}^{m})}^{2}}.\) This model implies that essential kinetic processes, such as CO dissociation by contact with adsorbed hydrogen, have already occurred. The first stage in the hydrogenation process is presumed to be fast and reversible, whereas the second step is presumed to be sluggish and rate-determining.