Environmental & Economic Advantages of CCS on CHP Plants

Environmental and Economic Advantages of Carbon Capture on Combined Heat and Power Plants

Combined Heat and Power (CHP) plants, also known as cogeneration plants, generate both electricity and useful heat from the same energy source. While CHP plants are more efficient than conventional power generation methods, they still emit carbon dioxide (CO2), a significant greenhouse gas, which contributes to climate change. If the fuel for the gas engine is renewable, such as biogas, hydrogen, syngas or biomethane, CHP can be a highly sustainable source of electricity and heat.

Integrating carbon capture technology into CHP systems offers a significant opportunity to boost their environmental performance. By capturing CO2 emissions produced during combustion, this technology can substantially lower the carbon footprint of CHP operations. This approach is particularly effective in facilities using biogas, aligning with the shift towards renewable gases such as biogas and hydrogen. These gases, sourced from sustainable materials, can power CHP systems and further reduce greenhouse gas emissions. Biogas-powered CHP systems with carbon capture have the potential to achieve a net reduction in atmospheric CO2, as the carbon originates from short-term, non-fossil sources.

What drives the need for CO2 extraction in CHP plants?

There are several key factors:

1. Environmental Regulations and Policies:

Many countries and regions have stringent environmental regulations aimed at reducing greenhouse gas emissions. CHP plants must comply with these regulations to avoid penalties and continue operations. CO2 extraction technologies help CHP plants meet these regulatory requirements by capturing and reducing their CO2 emissions.

2. Climate Change Mitigation:

Reducing CO2 emissions is critical in the fight against climate change. CHP plants, even though more efficient, still produce CO2. Implementing CO2 extraction helps minimize their carbon footprint, contributing to global efforts to limit temperature rise and its associated impacts on the environment and human health.

3. Sustainability Goals:

Many organizations and governments have set ambitious sustainability targets, including achieving net-zero emissions. CO2 extraction from CHP plants is a significant step towards reaching these goals, ensuring that energy production becomes more sustainable and environmentally friendly.

4. Economic Incentives:

In some regions, there are economic incentives for reducing CO2 emissions, such as carbon credits or tax benefits. By investing in CO2 extraction technologies, CHP plants can benefit financially while also contributing to environmental protection.

5. Technological Advancements:

Advances in carbon capture and storage technologies have made it more feasible and cost-effective for CHP plants to implement these systems. Technologies such as carbon capture and storage (CCS) and carbon capture and utilization (CCU) can be integrated into CHP plants to capture CO2 and either store it underground or use it for other industrial processes.

6. Public and Stakeholder Pressure:

There is increasing pressure from the public, investors, and other stakeholders for companies to reduce their environmental impact. CHP plant operators face growing scrutiny and are often required to demonstrate their commitment to sustainability, making CO2 extraction an important aspect of their operational strategy.

7. Enhanced Plant Efficiency and Competitiveness:

By capturing and utilizing CO2, CHP plants can improve their overall efficiency and competitiveness. For example, captured CO2 can be used in various industrial applications, such as enhanced oil recovery, carbonated beverages, and chemical production, creating additional revenue streams.

How is the carbon dioxide extracted?

CO2 extraction can be carried out on CHP plants in several ways:

Pre-Combustion Capture: Fuel is partially oxidized to produce a mixture of hydrogen and carbon dioxide before combustion. The carbon dioxide is then separated from the hydrogen, which is used as a clean fuel for power generation.

Post-Combustion Capture: This involves using solvents or other materials to absorb CO2 from the flue gas, which is then separated and stored or utilized.

Oxy-Fuel Combustion: The fuel is burned in a mixture of oxygen and recycled flue gas, rather than air. This results in a flue gas that is mainly CO2 and water vapor, making carbon capture easier.

Making use of captured carbon

In all cases, there are good environmental and/or economic reasons to utilise captured carbon. By capturing CO2 emissions generated during the combustion process, this technology can significantly reduce the carbon footprint of CHP operations. This CO2 can also be used to create revenue streams in carbonated beverage production, or other chemical production usage, such as urea manufacture or synthetic fuel production.

All these processes require dry, contaminant-free CO2, so the implementation of online instrumentation – such as gas chromatographs, oxygen analyzers and moisture analyzers – in CO2 drying and transport projects offers significant process, safety, and economic benefits. These instruments provide real-time, continuous monitoring and control, ensuring that CO2 remains within optimal purity and within O2 and moisture content specifications. This not only enhances process efficiency and quality but also ensures the safety and longevity of infrastructure, reduces maintenance costs, and ensures regulatory compliance. By integrating these advanced analytical tools, carbon capture projects can achieve higher levels of reliability, safety, and economic viability, contributing effectively to climate change mitigation efforts.

The QMA601 Moisture in CO2 Analyzer is the latest variant of the well-established Quartz Crystal Microbalance analyzer range from Michell Instruments. This analyzer is the result of some novel development work and offers an accurate, reliable and traceable measurement solution for CO2 capture, transportation and storage projects.

The QMA601 requires only minimal routine maintenance to ensure low cost of ownership. It features an intuitive ‘through the glass’ touchscreen interface, which is both easy to use and enables the analyzer to be interrogated and configured without the need for a hot works permit. In applications where control and/or monitoring of O2 is needed, for instance to reduce oxidation and protect integrity of plant materials, oxygen content measurement can be considered.

The XTP601 Oxygen Analyzer for safe or hazardous areas is a robust, linear and stable device that is used for measurements in gases such as biogas, methane, hydrogen, nitrogen or carbon dioxide. The analyzer is SIL2 capable, making it suitable for use in hazardous environments.