Life Cycle Assessment of Magnesium‐Impregnated Biochar Production and its Application for Nutrient Removal and Soil Improvement in Rice Cultivation

Abstract Rice husks, a significant byproduct of rice cultivation, constitute ≈20% of the total production weight. Their management is often inadequate, with unsustainable practices such as uncontrolled burning generating severe environmental impacts. This study conducts a life‐cycle analysis (LCA) to evaluate biochar production, its use as a nutrient adsorbent in water treatment, and subsequent land application as a rice husk treatment system, comparing it with the alternative system of direct incineration for energy generation. The assessment utilizes OpenLCA 2.2.0, which integrates laboratory data and open‐access databases, along with the IMPACT2002+ method, to evaluate environmental impacts. The results indicate that the biomass preparation process generates the most significant environmental burdens due to its intensive energy consumption and the use of reagents. In contrast, land application generates net benefits in some of the evaluated categories, highlighting its potential as a carbon sink and sustainable alternative for agriculture. Sensitivity analysis of variations in energy source, MgCl₂ concentration, and applied biochar dose reveals that wind energy is the most favorable option. High MgCl₂ concentrations increased the impacts, and varying the biochar dose applied to the soil does not generate significant changes in most of the impact categories evaluated.