Solvent-based Capture - CCUS Terms

Description:
Solvent-based Capture is a method of capturing carbon dioxide (CO2) from gas streams using liquid solvents. These solvents, typically amine-based, chemically react with CO2 to form a compound that can be separated from the gas stream. The CO2 is then released from the solvent through a regeneration process, allowing the solvent to be reused.

Explanation:
Solvent-based Capture is significant in the broader framework of Carbon Capture, Utilization, and Storage (CCUS) because it provides a widely used and effective method for capturing CO2 from industrial emissions. Here’s how solvent-based capture integrates with the CCUS framework:

• Carbon Capture. Solvent-based capture involves passing flue gas or other CO2-containing gas streams through a liquid solvent that reacts with the CO2. Common solvents include amines such as monoethanolamine (MEA). The chemical reaction between the solvent and CO2 forms a compound that can be easily separated from the gas stream. The CO2-rich solvent is then heated or depressurized to release the captured CO2, which is collected for further processing.
• Utilization. After capturing CO2, the solvent-based capture process can release it for utilization in various industrial applications. Captured CO2 can be converted into synthetic fuels, chemicals, and building materials. The use of solvent-based capture in CO2 utilization processes enhances the economic viability and sustainability of these technologies by providing a steady supply of captured CO2.
• Storage. Captured CO2 from solvent-based capture systems can be compressed and transported to storage sites for secure and permanent sequestration. This involves injecting CO2 into geological formations such as saline aquifers or depleted oil and gas fields. Solvent-based capture provides a reliable source of captured CO2 for long-term storage, contributing to significant reductions in atmospheric CO2 levels.

Advantages:
Solvent-based capture is a mature and well-established technology with a proven track record in industrial applications. It offers high capture efficiency and can be applied to various gas streams with different CO2 concentrations. The technology is adaptable to existing industrial processes, making it suitable for retrofitting. Additionally, solvent-based capture supports the integration of carbon capture with CO2 utilization and storage, enhancing the overall effectiveness of CCUS technologies.

Challenges:
Solvent-based capture processes can be energy-intensive, particularly during the solvent regeneration stage, leading to higher operational costs. The solvents used in the capture process may degrade over time, necessitating replacement and disposal, which can have environmental and economic impacts. Ensuring the safe handling and storage of solvents is essential to minimize health and environmental risks. Addressing potential emissions and by-products from the capture process requires effective management and regulation.

In summary, Solvent-based Capture is a method of capturing CO2 from gas streams using liquid solvents. In the context of Carbon Capture, Utilization, and Storage (CCUS), solvent-based capture provides a widely used and effective method for capturing CO2, with applications in both utilization and storage. Despite challenges related to energy use, solvent management, and environmental impacts, solvent-based capture is essential for advancing CCUS and achieving significant reductions in greenhouse gas emissions.