Google "Broadwing": 400-MW Gas Power Plant to Store CO₂ Deep Underground

Google intends to build and operate a 400 MW gas power plant with Carbon Capture and Storage (CCS) in Decatur, Illinois, under the Broadwing project. Google announced this on Thursday in its blog. The CO₂ produced during gas combustion is to be captured and permanently stored about a mile (approximately 1.6 km) deep underground. Google plans to use the electricity produced by its first CCS gas power plant, Broadwing Energy, primarily to power its own local data centers with what it describes as clean energy.

Broadwing Energy is to be built at an industrial facility of Archer Daniels Midland (ADM) in Decatur. The company Low Carbon Infrastructure (LCI) is responsible for project development. ADM already has experience with storing CO₂ from ethanol production, Google writes. For Broadwing Energy, ADM's approved Class IV sequestration facilities will be used to bind the CO₂ produced during gas combustion and then store it at a depth of over a mile underground.

CO₂ Capture and Storage

The process used works in three stages: absorption, regeneration, and compression and storage. In the absorption stage, the flue gas resulting from gas combustion flows through a large absorption column, where it comes into contact with an amine-water solution. The amine, organic compounds of ammonia, chemically reacts with the CO₂ in the flue gas and combines with the CO₂ to form a stable compound, leaving hardly any CO₂ behind.

In the absorption phase, the CO₂-containing amine solution is heated with steam in a regenerator. The heat breaks the chemical bond between the CO₂ and the amine, releasing pure CO₂ gas. The amine solution, now containing very little CO₂, is cooled and returned to the absorber to bind CO₂ again.

In the third phase of the process, the CO₂ gas is cooled and compressed into liquid form. It is then permanently stored in geological formations underground. Specifically, this will happen in Illinois in the Mount Simon Formation, a sandstone reservoir at a depth of over a mile, which is capable of holding large amounts of liquid and is ideal for storing the CO₂ liquid.

Approximately 90 percent of the CO₂ produced by gas combustion can be captured this way, representing a significant reduction in CO₂ emissions compared to conventional gas power plants. However, critics of electricity production based on fossil fuels argue that this delays the transition to renewable energy sources.

However, it will take a few years for Broadwing Energy to be implemented: the necessary regulatory approvals are expected to be obtained in 2025. Construction of the facility could then begin in 2026, with it being ready for operation by the end of 2029. The facility is scheduled to commence operations in early 2030.

(olb)