A Pilot Plant Fixed-Bed Reactor for Dehydrogenation of Heavy Paraffins: Experimental and Numerical Elucidation

The first step in producing eco-friendly biodegradable detergents is the dehydrogenation process of heavy paraffins. Despite its importance, a few studies have been conducted on the process. In this paper, the heavy paraffin dehydrogenation process was elucidated using Computational Fluid Dynamics (CFD) to simulate the performance of a pilot-scale fixed-bed reactor, investigate the effects of key operating parameters (temperature, pressure, LHSV, and H₂/HC ratio), and identify the best operating conditions for maximizing mono-olefin yield and selectivity. The validation of CFD simulation results was performed by comparing them with pilot plant data; The absolute relative deviations were less than 5.5%, indicating the adequacy of the simulation was confirmed. The CFD simulation results showed that the paraffin conversion and mono-olefin yield are higher at a lower Hydrogen-to-Hydrocarbon molar ratio (H2/HC). However, the mono-olefin selectivity is higher at higher H2/HC ratios. Therefore, an H2/HC between 4 and 6 would be suggested as the best condition. Also, the conditions to achieve the best system performance were the temperature between 460 and 470 oC and LHSV of 15 hr-1.