Silicate Carbon progress report 2023

Background

Silicate is exploring how returned concrete and other waste mineral products can be used to capture CO2 cheaply and quickly. It is spread on fields, replacing the need for liming while capturing CO2 at the same time. This method could potentially capture hundreds of millions of tonnes of CO2.

This is a low-tech way of cheaply storing CO2 using a waste stream that is currently underutilized. By being the first customer, we help Silicate test and prove the viability of the method. Silicate's approach to measurement in the field also offers a robust assessment of actual carbon removal rates and will be a verifiable measure of carbon removal volumes.

Progress

Over the past year, Silicate has made significant strides in its mission. They applied approximately 1,300 tonnes of milled returned concrete to about 130 hectares of land in Wexford, SE Ireland, gaining valu- able insights into the geochemistry underpinning their carbon removal solution. This large-scale trial has laid the groundwork for further de- ployment of their method, and has been recognized internationally, with Silicate winning the THRIVE | Shell Climate-Smart Agriculture Challenge at SXSW and being featured in various international media outlets.

The field of enhanced weathering is still in its infancy, and comprehensive field data demonstrating reliable and economically viable carbon dioxide removal at scale is yet to be widely published. Silicate has identified two critical areas for further investiga- tion: the weathering of minerals by non-carbonic acids, and the impact of soil amendments on the existing organic carbon pool of soils.

In response to these challenges, Silicate has been growing its science team and expanding its operations, planning to undertake enhanced weathering trials in Illinois, US. They have also been developing a broader approach to carbon removal mea- surement in enhanced weathering that more directly quantifies carbon drawdown, using a machine learning approach for reliable CDR estimation across a broad range of soil types.

Looking ahead, Silicate plans to con- tinue its research and recommence commercial-scale deployments in late 2024/early 2025, with the goal of delivering verified CDR tonnes before the end of 2026. They are also pre- paring to publish two peer-reviewed papers on terrestrial enhanced weathering before the end of the year, contributing to the grow- ing body of knowledge in this field.

We were the first buyer of tonnes from Silicate, and the CTF support has been of monumental importance for the organization to do the work described above.