Precombustionmenetelmässä

Precombustionmenetelmässä, often translated as pre-combustion capture, is a technology designed to reduce carbon dioxide emissions from fossil fuel power plants. This process involves converting the fuel, typically natural gas or coal, into a mixture of hydrogen and carbon dioxide before combustion. This is achieved through a process called gasification or steam reforming.

In this pre-combustion stage, the fuel reacts with steam and oxygen at high temperatures to produce syngas, which is primarily carbon monoxide and hydrogen. The carbon monoxide is then further reacted with steam in a water-gas shift reaction to produce more hydrogen and carbon dioxide. The resulting stream contains a high concentration of carbon dioxide, which can then be easily separated from the hydrogen.

The separated hydrogen is then used as fuel in a gas turbine or other combustion system, producing electricity with significantly reduced CO2 emissions as the primary byproduct of combustion is water vapor. The captured carbon dioxide can then be transported and stored underground in geological formations, a process known as carbon capture and storage (CCS). Pre-combustion capture offers the advantage of separating CO2 at a higher pressure and concentration compared to post-combustion capture, potentially making the capture process more efficient and less costly. However, it requires a significant upfront investment in new equipment and can lead to a decrease in overall energy efficiency of the power plant.