Economic Feasibility Study of Nanosilica Production from Palm Kernel Shell Ash under Compositional and Throughput Uncertainty

Abstract

This study presents the techno-economic analysis of producing high-purity nanosilica from palm kernel shell (PKS) ash as a potential complementary non-mined silica source. We developed a process model incorporating material and energy balances and assessed economic performance using discounted cash flow analysis with a 10-year plant lifetime and a 22% target internal rate of return (IRR). The study placed particular emphasis on the impact of ash composition and plant throughput variability on overall process economics. In this study, the SiO₂ content in the feedstocks varies significantly (46–65%), directly affecting silica yield, chemical consumption, and utility demand. Consequently, operating expenditure varies significantly across ash sources, with chemical reagents emerging as the dominant cost driver. To some extent, plant capacity analysis showed that increasing throughput improves capital utilization and reduces unit production cost. However, the benefit diminishes at higher capacities, where operating costs become the dominant factor. We also conducted a sensitivity analysis incorporating compositional variability and throughput fluctuations. The results indicated that economic viability is constrained within a specific range of ash quality and throughput. While capacity expansion beyond feedstock-limited conditions can enhance profitability, it introduces supply risks that require careful management.