Insights into siloxane removal from biogas in biotrickling filters via process mapping-based analysis

• Simultaneous removal of D4 and D5 from biogas in BTF is evaluated.
• A competitive D4 and D5 removal mechanism is pointed out.
• A preferential pathway towards performance minimization is identified.
• Main hidden causes limiting system performance are depicted.
• Performance depends on mass transfer, biomass density, siloxane breakdown.

Data process mapping using response surface methodology (RSM)-based computational techniques is performed in this study for the diagnosis of a laboratory-scale biotrickling filter applied for siloxane (i.e. octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5)) removal from biogas. A mathematical model describing the process performance (i.e. Si removal efficiency, %) was obtained as a function of key operating parameters (e.g biogas flowrate, D4 and D5 concentration). The contour plots and the response surfaces generated for the obtained objective function indicate a minimization trend in siloxane removal performance, however a maximum performance of approximately 60% Si removal efficiency was recorded. Analysis of the process mapping results provides indicators of improvement to biological system performance.