As the world’s population continues to rise, so does our carbon footprint. With the increasing concern about climate change, we must find ways to reduce our greenhouse gas emissions and implement effective methods for carbon capture and storage. One promising technique is Enhanced Rock Weathering (ERW), where a certain type of rock is ground and spread over soil to capture carbon dioxide from the atmosphere and store it safely underground. However, not all rocks are created equally, and it’s crucial to understand the different types of rocks and their properties to choose the most effective options for ERW. Learn more about this!
Different types of rocks and minerals used in Enhanced Rock Weathering (ERW)
Carbon capture and storage can play a significant role in mitigating climate change. One of the latest innovations in this field involves Enhanced Rock Weathering (ERW). ERW is a process that helps in capturing carbon dioxide by adding specific types of rock dust to soil.
This technology uses crushed rock and minerals to accelerate and boost a natural process thare occurs throughout millions of years. There are a few rocks that can be used in this technique, among which we can mention:
1. Glauconite
Glauconite, also known as greensand, is a type of silicate mineral, more specifically an iron potassium phyllosilicate. It has known plant nutritional properties, being used as a fertilizer in U.S. since the 1700’s.
Additionally, studies like Glauconite dissolution kinetics and application to CO2 storage in the subsurface show that it is effective in capturing carbon. Studies also show that glauconite has a viable rate of carbon capture, as well as efficient velocity on the process of removing and storing CO2 on the ground layer.
Othe benefit of using glauconite for ERW is that it helps to raise soil fertility, boosting crops yeld and the agricultural activity.
2. Basalt
Basalt is a volcanic rock that is widely used in ERW due to its availability and effectiveness in capturing carbon dioxide. Additionally, basalt weathers slowly, providing long-lasting carbon sequestration. Studies have shown that the application of basalt can capture up to 2 tons of CO2 per hectare per year.
Basalt also contains essential minerals, which can improve crop yield and soil fertility. These nutrients include calcium, magnesium, and iron that help to increase soil pH and promote plant growth.
As a bonus, using basalt can also reduce the use of chemical fertilizers, which contribute to greenhouse gas emissions.
3. Serpentine
Serpentine is a magnesium-rich rock that is high in nickel. Serpentine has a low weathering rate but can release large amounts of magnesium and nickel that act as fertilizers and promote plant growth.
Additionally, serpentine can sequester carbon dioxide by transforming it into solid minerals. Studies have shown that the application of serpentine can capture up to 0.5 tons of CO2 per hectare per year.
4. Olivine
Olivine is a magnesium, iron-rich rock that is commonly found on Earth’s crust. Olivine weathers quickly, providing fast carbon sequestration. It reacts with atmospheric carbon dioxide to form carbonate minerals that can remain stable for thousands of years.
Some studies suggest that using olivine in fields can significantly reduce atmospheric carbon dioxide concentrations by up to 90% by the end of the century. Other research has shown that the application of olivine can capture up to 5 tons of CO2 per hectare per year.
5. Limestone
Limestone is a sedimentary rock that is rich in calcium carbonate. Although limestone weathers slowly, it can release substantial amounts of calcium, which can promote plant growth and increase soil pH.
The addition of limestone to soil can capture CO2 by transforming it into solid minerals. Studies have shown that the application of limestone can capture up to 1 ton of CO2 per hectare per year.
6. Dolomite
Dolomite is a carbonate rock that contains magnesium and calcium carbonate. Dolomite is commonly used in agriculture to enhance soil properties and supply essential plant nutrients.
Dolomite can capture CO2 by transforming it into solid magnesium carbonate. Studies have shown that the application of dolomite can capture up to 0.5 tons of CO2 per hectare per year.
It Is important to know and understand the properties of the raw materials used in ERW to boost its efficiency
Summarizing, ERW is considered a promising way of capturing carbon dioxide, showing itself as an innovative and environmentally friendly option for carbon capture and storage, and it’s worth exploring further.
Among the rock types that can be used in this technique, the ones discussed in this article have the potential to capture considerable amounts of CO2 per hectare per year. However, the effectiveness of each rock type may vary based on the soil type, climate, and other factors. It is crucial to conduct more research and experiments to determine the best rock type, application method, and rate of application for ERW.
In conclusion, understanding the different properties of the different rocks and minerals and their roles in ERW is essential for implementing effective carbon capture strategies and reducing our carbon footprint.
