Capture of CO2 through phosphogypsum and lye residues from the olive industry
L. Valdez-Castro, A.C. Bejarano-Nieto, R. Mendoza‐Serna, Adrián Pavón-Duarte, Víctor Morales‐Flórez, L. Esquivias
Abstract
A new carbonation procedure is presented to recycle waste from phosphoric acid production, known as phosphogypsum (PG). The PG is treated with lye (NaOH solution) used in the olive industry instead of commercial NaOH. Chemical analyses confirm that the reaction of these two industrial by-products shows very good carbonation efficiency. In addition, it has also been confirmed that the radionuclides present in the starting PG are mostly transferred to the solid by-product. The concentration of hazardous trace elements present in these solid by-products is low enough to allow their use in civil engineering applications. Therefore, this procedure can be a new management strategy for PG and waste streams from the olive industry and can be explored to exploit the potential of the PG by-product as a CO2 sequestration agent. In addition, it improves the economy of the process and mitigates the environmental impact of discharging of these caustics because it results in a neutral pH residual liquid.