In a groundbreaking development, scientists have discovered a novel method to sequester greenhouse gases using construction waste, potentially revolutionizing carbon capture efforts, writes Darren Orf for Popular Mechanics. This innovative approach, pioneered by an Irish startup called Silicate, involves spreading finely crushed waste concrete across agricultural fields. Contrary to expectations, this technique has shown promising results in increasing bicarbonate formation, thereby effectively capturing carbon while simultaneously improving soil conditions.
Traditionally, rock weathering—a natural process where minerals in the soil capture carbon and sequester it as calcium carbonate in the oceans—occurs at a slow pace. However, Silicate’s method aims to accelerate this process by utilizing waste concrete particles, which are approximately 1 millimeter in size. Initial trials conducted on a 100-acre farm south of Chicago have demonstrated the potential to remove significant amounts of CO2 from the atmosphere and trap it in the soil, equivalent to the emissions produced by dozens of cars annually.
The science behind Silicate’s approach is straightforward: the concrete, made from heated calcium carbonate, reacts with atmospheric CO2 to form bicarbonate ions, which are then absorbed into the soil. Notably, this process can potentially sequester carbon for tens of thousands of years. Moreover, besides carbon capture benefits, the use of concrete dust also acts as a pH amendment, enhancing soil health and leading to increased crop yields, as evidenced by a study on oats in Ireland.
While Silicate’s method holds promise in mitigating climate change and utilizing waste concrete, uncertainties remain regarding its long-term effects. Scientists, including Frank McDermott from University College Dublin, emphasize the need for further research to understand the downstream impacts fully. Despite its potential, enhanced rock weathering alone cannot solve humanity’s carbon emissions crisis, underscoring the imperative for comprehensive efforts to reduce greenhouse gas emissions at their source.
Read more here: https://www.popularmechanics.com/science/environment/a60537619/a-new-use-for-old-concrete-could-revolutionize-carbon-capture/