Regional carbon drawdown with enhanced weathering of non-hazardous industrial wastes

Countries around the world are taking active efforts to address the current climate crisis. Negative emissions technologies (NET) such as enhanced weathering will play a significant role in these efforts in the coming decades. Enhanced weathering is based on the terrestrial application of powdered natural or synthetic silicate minerals to remove carbon dioxide (CO2) from the atmosphere. In the latter case, non-hazardous industrial waste (NHIW) can react with water and CO2 from the atmosphere to achieve carbon drawdown through the acceleration of the naturally occurring weathering process. This approach also addresses the problem of sustainable industrial waste management. Besides, carbon drawdown also enhances soil quality for agricultural application sites. In the future, planning the large-scale implementation of enhanced weathering via carbon management networks can be facilitated by using optimization models. In this work, a source-sink model is developed for the proper allocation of NHIW to application sites. The method is demonstrated with a case study based at Shandong Province, China. Two scenarios are analyzed, with both achieving significant negative CO2 emissions. The CO2 sequestration rates for these two scenarios are determined as 12.73 Mt/y and 13.77 Mt/y, respectively. Scenario 1 shows that the system can achieve negative CO2 emissions at a cost of $ 184.25/t CO2, which is comparable to previously reported cost estimates. Given the necessary input data, the model can be used to generate case-specific estimates for any country. The increasing use of clean energy in the transport and crushing process will enhance CO2 sequestration of the system.