Toward a comprehensive standard for sustainable regenerated activated Carbon: Performance, Safety, and carbon reduction benefits.

This study was based on the status of the recycling industry of spent activated carbon (SAC) in China. By integrating national and industry standards (GB/T 7701.1-3, GB/T 13803.1-5, LY/T 3284-2021, etc.) with pollution control regulations (GB 34330-2017, GB 5085.7-2019, etc.), a quality and hazardous composition indicators system for regenerated activated carbon (RAC) used for industrial organic waste gas purification was constructed. The applicability of the indicators was verified by collecting test data from 10 effective samples of typical recycling enterprises nationwide, including iodine adsorption value, wear resistance strength, carbon tetrachloride adsorption rate, and 11 heavy metal limits. Furthermore, a comparative carbon footprint analysis was conducted based on industrial project data, quantifying the carbon reduction benefits of regeneration. The results showed that the physical properties (moisture content ≤ 2.85%, abrasion resistance ≥ 96%) and adsorption properties (iodine number 782---860 mg/g) of RAC met the overall standards, but the carbon tetrachloride adsorption rate (44.9% - 46.82%) only met the requirements for qualified products. The hazardous components (such as mercury 0.013---0.088 mg/kg, lead 1.4---10.1 mg/kg) were significantly lower than the limit values. Critically, the carbon footprint of RAC (1.632---2.736 tCO2e/t) was 46.5% - 68.1% lower than that of activated carbon (5.112 tCO2e/t), demonstrating a substantial climate mitigation benefit. This study provides a comprehensive technical support, encompassing quality, safety, and environmental benefits, for the standardized application and market promotion of RAC products, which is expected to promote the high-quality development of SAC resource utilization industry.