EXPLORATION OF CHEMICAL ACTIVATION USING Mg AND Ca CHLORIDES FOR OBTAINING BIOCHARS FROM SOURSOP SEEDS (Annona muricata).

The capture of CO2 for subsequent use in the synthesis of high-value-added products using biochars is a solution with significant potential to address environmental issues. However, the results are strongly dependent on the synthesis process and the addition of compounds that impregnate the carbon surface with the metal from the salt used. To assess the influence of salt on the precursor during pyrolysis, concentrations of 5% and 8% of metallic chlorides (CaCl2 and MgCl2) were employed on pre-cleaned and dried soursop seeds. The objective was to investigate how salt impacts the textural characteristics of the resulting biochars concerning thermal conditions. This process yielded five solids, which were subjected to various characterization techniques. The results revealed that these solids function as CO2 adsorbents, with BET surface areas ranging from 140 to 285 m2/g, as determined by CO2 analysis. Furthermore, the quantities of adsorbed CO2 showed variations in the performance of each sample. Additionally, DRIFT analysis of CO2 showed sharp peaks corresponding to specific CO2 adsorptions, particularly in solids activated with CaCl2. The employed characterization techniques facilitated the identification of potential methods to enhance basicity and surface area in solids that exhibited lower performance.