Process Optimization of Activated Carbon Fiber Using Response Surface Methodology

Abstract

Response Surface Methodology (RSM) was employed to optimize the activation yield (%) and specific surface area (m2/g) in the manufacture of activated carbon fibers. Isotropic petroleum pitch was melt‑blown into non‑woven webs (~ 25 µm), then stabilized (280 ℃, air), carbonized (800 ℃, N2), and steam‑activated (800–900 ℃) as discrete steps. A Box-Behnken Design (BBD) that encoded eight process variables spanning stabilization, carbonization, and activation generated a second-order polynomial model (R2 = 0.969 for yield and 0.918 for surface area). According to the RSM model, the key process variable for achieving a high activation yield was the stabilization holding time, with optimal results observed at 1 h. The main process variable for maximizing the specific surface area was the activation temperature, with the optimum value being 900 ℃. Validation under the predicted optimum (900 ℃, 1.2 g/min steam, 45 min) produced ACFs with 34.6 wt. % yield and 2,429.5 m2/g surface area, confirming the model’s predictive accuracy. These results confirm that RSM offers a statistically robust route to tailoring pitch-based activated carbon fibers (ACF) for high-performance adsorption applications.