19. What is gasification?

All organic substances decompose over time, with the more complex materials and molecules being broken down into simpler ones. The ultimate products of decomposition are carbon dioxide, water and energy.

There is always energy released when complex organic compounds break down into simpler material. However, this energy is difficult or impossible to capture if the decomposition occurs naturally over a long period of time.

Gasification speeds up this natural process and allows us to capture the energy that is contained in all organic matter. In this process carbonaceous (organic) materials, such as coal, petroleum, biofuel, or biomass, are converted into gasses by subjecting the feedstock to high temperatures with low, controlled amount of oxygen. The process can also make use of steam.

Gasification relies on elevated temperatures, generally above 700°C, which distinguishes it from other processes (e.g., anaerobic digestion) that produce biogas.

While different gasification systems have different configurations, the basic model is demonstrated in the following diagram:

The gases produced (often referred to as synthetic gas or snygas) are captured and processed to remove any organic particles that might have been released from the organic matter and to remove any organic chemicals that may not easily burn.

The processed syngas can be used to power cars, busses, heat homes, run electrical generators, etc. In other words syngas can be used anyplace that natural gas is used today.

To learn more about the gasification process, visit the gasification network here.

It is not efficient to completely destroy all of the organic matter through a basic gasification process. In other words, some of the feedstock remains after the process has been completed. This “left over” material still needs to be disposed of by an alternative method, such as the ROC or in a landfill.