Catalytic CO2 Gasification of Rice Husk Char for Syngas and Silica-Based Nickel Nanoparticles Production

Abstract

The nickel-catalyzed CO2 gasification of rice husk char (RHC) was studied. In this work, carbon conversion is studied by thermogravimetric analysis (TGA) and a packed-bed reactor. The key influence parameters including nickel-loading amount and gasification temperature were investigated. In the absence of nickel, the carbon conversion efficiency of 100% was achieved in 40 min at 1000 °C, whereas this time was extended to 130 min at 700 °C. Although the use of high temperatures improved char reactivity, relatively high temperatures can shift the reaction rate toward the pore-diffusion-controlled regime. Also, the addition of nickel catalyst can improve the biochar reactivity by reducing the activation energy, in terms of the improvement of the carbon conversion and its rate. In the view of RHA Ni recycling, the silica-based nickel nanoparticles could be recycled in various catalytic applications.