Transforming Power Plants: How Syngas Can Contribute to Lower CO2 Emissions

In the quest for sustainable energy solutions, syngas has emerged as a promising alternative fuel. Syngas, or synthesis gas, is a mixture of hydrogen, carbon monoxide, and other hydrocarbons. It is produced through the gasification of organic materials such as biomass, coal, or waste. Its versatility and cleaner combustion properties make it an attractive option for various applications, including power generation.

Gas turbines have traditionally relied on natural gas and other fossil fuels. However, the need to reduce carbon emissions, on the one hand, and enhance energy security, on the other, has spurred interest in alternative fuels like syngas. The potential of syngas to serve as a fuel for gas turbines lies in its ability to utilize waste materials. At the same time, in the right combinations, it can reduce greenhouse gas emissions, thus contributing to a more sustainable energy landscape.

Despite its advantages, the vast majority of the existing fleet of gas turbine plant designs are not directly capable of burning syngas. This presents both a significant challenge and an opportunity for the service sector. Through modifications and upgrades, service providers can enable the current fleet to operate efficiently on syngas, thereby unlocking its full potential.

The Potential of Syngas as a Fuel for Gas Turbines

Syngas offers several advantages over traditional fossil fuels. One of the primary benefits is its ability to be produced from a variety of feedstocks, including waste, which makes it an environmentally-friendly alternative to traditional fossil fuels. A second benefit is that syngas is often a by-product of industrial production and would be a perfect match for a nearby power plant.

When it comes to environmental benefits, syngas stands out due to its cleaner combustion properties. Most emissions are already captured during the syngas production process. When burning syngas as a fuel, the higher hydrogen content can result in lower carbon dioxide emissions compared to natural gas. Additionally, the use of syngas can significantly reduce the emission of other harmful pollutants such as sulfur oxides (SOx) and nitrogen oxides (NOx), contributing to improved air quality and compliance with stringent environmental regulations.

From an operational perspective, syngas can enhance the efficiency and performance of gas turbines. Additionally, using locally available feedstocks for syngas production can enhance energy security and reduce transportation costs.

One of the main concepts for utilizing syngas in electrical generation is the Integrated Gasification Combined Cycle (IGCC), where the syngas production facility is fully integrated into the power plant.? In this application a higher-emission fossil fuel, such as coal, can also be gasified into fuel gas to reduce the overall environmental impact.

No Light Without Shadows

The existing fleet of gas turbines presents a significant challenge when it comes to burning syngas. These turbines are primarily designed to operate on natural gas and other conventional fuels, which have different combustion characteristics compared to syngas. The differences in calorific value, flame speed, and combustion properties necessitate modifications to the combustion system and other components of the gas turbine plants.

One of the primary technical challenges is the need to adapt the combustion system to handle the unique properties of syngas. The high hydrogen content in syngas can lead to issues such as flashbacks, where the flame propagates back into the burner, causing potential damage to the turbine. Additionally, the lower calorific value of syngas compared to natural gas means that larger volumes of fuel are required to achieve the same power output. This can impact the design and operation of the fuel delivery system.

In addition to combustion system modifications, enhancing the overall performance and reliability of the turbines is crucial. This may involve upgrading control systems to optimize the combustion process and ensure stable operation under varying conditions.

Looking at Real-Life Examples

Since the 1960s where Siemens Energy started with the first gas turbine projects running on syngas, our turbines have accumulated more than 2.5 million operating hours with these alternative fuels.

Many of these projects were milestones, being the first to successfully test specific gasification processes like the IGCC in Luenen, Germany in 1972, or the projects in Buggernum, Netherlands and Puertollano, Spain.

And the journey continues with the IGCC Jazan in Saudi Arabia, which is the world’s largest IGCC built to date. ?The plant began commercial operation in 2020, and I had the opportunity to visit it in September.

Jazan uses feedstock from the nearby Saudi Aramco refinery to produce hydrogen and syngas in the gasification process. The syngas is then used as fuel for the combined cycle power plant. With a 5 times 2x1 configuration that includes 10 SGT6-5000F gas turbines, the power plant can produce 3.8 GW of power, enough to supply the refinery and thousands of surrounding households and businesses.

The example of Jazan perfectly illustrates where an IGCC makes sense: When syngas can be produced from waste or a by-product of industrial production processes. And since syngas is a comparably low emissions fuel, such a solution makes sense ecologically as well as economically.

Transforming Power Plants to Lower Emissions

In the complex energy landscape IGCCs will not be the only solution by far on the path to a decarbonized energy system. As discussed in previous articles, we must be open to using all available technologies, including but not limited to CCUS, nuclear energy, alternative fuels like hydrogen, and Rotating Grid Stabilizers to increase the infeed of renewable energy. Depending on infrastructure and the availability of feedstock for gasification, IGCCs and syngas as alternative fuels will certainly continue to have a place in our future energy systems.

For the operating fleet, Service modernizations and upgrades will play a crucial role. Successfully retrofitting existing gas turbines to burn syngas not only extends the lifespan of these assets but also aligns with our global efforts to reduce greenhouse gas emissions and transition to a low-carbon economy.