Phenol Concentration in Liquid Smoke Production from Rubberwood by Experiment and Simulation with CFD Modeling

Abstract

Liquid smoke is produced through condensation resulting from the pyrolysis process of rubberwood, without the presence of oxygen. One of the dominant contents of liquid smoke products is phenol. Therefore, this study aimed to examine the molar concentration of simulated liquid smoke and the comparison between the experimental and simulated molar concentrations. The simulation used Ansys Fluent 19.2, a Computational Fluid Dynamics (CFD) program using the finite volume method in its solution. The several stages in completing Ansys simulation include pre-processing, meshing, processing, and post-processing. The geometry depicted in this study was a 2-dimensional pyrolysis reactor. Assumptions made for the simulation comprised using lignin as raw material, along with specified flowrate, and pyrolysis time. The results showed that based on the reaction mechanism, lignin in the pyrolysis process produced a phenol yield of 4.52%. In the final stage, quantitative data simulation results were obtained in the form of molar concentrations produced from liquid smoke products. The molar concentrations in the simulation during pyrolysis for 1, 2, 3, 4, and 5 hours were 0.00183512, 0.0017854, 0.00170856, 0.0017628, and 0.00166788 kmol/m3, respectively. The experimental molar concentration results also showed the same pattern as the simulation data. At 4 hours of pyrolysis, the molar concentration of phenol increased, resulting in liquid smoke with the best quality. A comparison of liquid smoke molar concentration for the simulation and experiment indicated a minimal difference of 0.005%.