Synthesis Gas (Syngas) Power Generation
Converting process-derived syngas into efficient on-site power and heat.
About Syngas
Synthesis gas, commonly referred to as syngas, is a combustible gas mixture produced as a by-product or intermediate stream in a range of industrial and thermal conversion processes. Typical sources include gasification of biomass, waste or coal, as well as certain chemical and refining processes.
Syngas generally contains a combination of hydrogen, carbon monoxide, carbon dioxide and nitrogen. Historically, surplus syngas has often been flared or underutilised where no immediate process demand exists.
Advances in gas engine technology now allow syngas to be used effectively for power generation and combined heat and power (CHP). By converting syngas into electricity and useful heat, operators can improve overall process efficiency, reduce flaring and recover value from an existing gas stream.
Benefits of Syngas Power Generation
Syngas power generation enables the productive use of a variable process gas while delivering operational, environmental and efficiency benefits.
Using syngas for on-site power generation provides an alternative to flaring, allowing excess or intermittent gas streams to be utilised rather than disposed of. This improves overall energy recovery from industrial processes.
Modern gas engine systems are capable of stable operation despite fluctuations in syngas composition, calorific value and hydrogen content. Reliable power generation can be maintained even where gas quality varies over time.
When configured for combined heat and power, overall efficiencies can be significantly increased through recovery of thermal energy for use within the host process or facility. This reduces the need for additional fuel input and improves total system efficiency.
From an environmental perspective, syngas utilisation reduces flaring and associated emissions while supporting more efficient use of primary energy inputs within industrial systems.
Discover More
Syngas Characteristics and Sources
Combustion Behaviour and Engine Output
Typical Syngas Composition
Fuel Gas Quality and Contaminant Control
Syngas Characteristics and Sources
Synthesis gas composition varies widely depending on feedstock and gasification process. Typical components include hydrogen, carbon monoxide, carbon dioxide and nitrogen, with trace contaminants depending on upstream conditions.
Syngas is commonly produced from:
• Biomass gasification
• Waste-to-energy and refuse-derived fuel gasification
• Coal or coke gasification
• Chemical and refining process off-gases
In many industrial applications, syngas is generated continuously as part of the core process but exceeds immediate process demand. Power generation therefore provides an effective route to utilise surplus syngas rather than flaring or disposal.
Calorific value is generally lower than natural gas and can fluctuate significantly. Hydrogen-rich syngas exhibits fast combustion characteristics, while carbon-monoxide-rich gas burns more slowly, requiring carefully controlled combustion strategies.
Combustion Behaviour and Engine Output
Hydrogen burns significantly faster than methane, which is the reference fuel for conventional gas engines. Without appropriate control measures, fast combustion can lead to pre-ignition, knocking and backfiring within the engine cylinders.
To manage these effects, syngas engines incorporate specific technical adaptations, including modified combustion control strategies and dedicated safety systems. As a result, engine output when operating on syngas is typically reduced to 50–70% of the equivalent natural gas rating.
For example, an engine rated at 1,063 kW on natural gas would typically deliver a maximum output of approximately 730 kW when operating on syngas, depending on gas composition.
Typical Syngas Composition
Syngas composition depends on the chemical characteristics of the feedstock and gasification process. Typical component ranges are shown below:
| Component | Typical composition (%) |
|---|---|
| Hydrogen (H2) | 20–40 |
| Carbon Monoxide (CO) | 35–40 |
| Carbon Dioxide (CO2) | 25–35 |
| Methane (CH4) | 0–15 |
| Nitrogen (N2) | 2–5 |
These ranges highlight the inherent variability of syngas and the importance of flexible engine design and control systems.
Fuel Gas Quality and Contaminant Control
A wide range of hydrogen-rich and carbon-monoxide-rich syngases can be used in gas engines. However, as with all engine fuels, defined limits apply to individual gas components and contaminants.
Gas contaminants — most notably tar and moisture — represent a key technical challenge for syngas utilisation. Inadequate gas cleaning or excessive humidity can adversely affect combustion stability, engine components and long-term reliability.
Appropriate gas treatment, drying and filtration systems are therefore required. Detailed fuel gas quality limits for syngas operation are defined within the applicable special gas technical instructions and must be considered during system design.
Syngas Engine Power Generation and CHP Integration
Gas engines used for syngas applications are specifically configured to operate reliably with low and variable calorific values, high hydrogen content and fluctuating gas composition. Advanced engine management systems continuously monitor gas quality and dynamically adjust combustion parameters to maintain stable and efficient operation, while dedicated safety systems manage fast flame speeds and ensure reliable ignition under changing conditions.
Syngas engine systems are modular and can be sized to match available gas volumes, allowing flexible integration into industrial processes. Electrical outputs typically range from several hundred kilowatts to multi-megawatt installations, supporting both base-load and variable operation.
When configured for combined heat and power (CHP), syngas engines generate electricity while simultaneously recovering useful thermal energy in the form of hot water or steam. This recovered heat can be used directly within the host process, improving overall system efficiency and reducing the need for supplementary fuel.
Syngas power generation systems are commonly deployed within industrial plants where gasification or thermal conversion processes are already in operation. Gas engines offer rapid load response and can operate continuously or flexibly depending on gas availability and process conditions.
Frequently Asked Questions about Coal Gas Power Generation
Technical and Engineering
Can gas engines operate on low-calorific syngas?
Yes, gas engines can be configured to operate on low-calorific syngas, provided combustion control and safety systems are appropriately designed.
How do engines manage high hydrogen content in syngas?
Advanced control strategies manage fast combustion associated with hydrogen-rich gas, ensuring stable and controlled engine operation.
Is syngas suitable for combined heat and power?
Yes, syngas engines are well suited to CHP applications where there is a consistent demand for recovered heat.
Financial and Commercial
Does syngas power generation improve process efficiency?
Yes, converting syngas into electricity and heat improves overall energy recovery from industrial processes.
Can systems be scaled with changing syngas production?
Yes, modular gas engine systems allow capacity to be adjusted as syngas availability changes.
Environmental and Sustainability
Does syngas utilisation reduce flaring?
Yes, using syngas for power generation reduces flaring and associated emissions.
How does syngas power generation support emissions reduction goals?
Improved energy efficiency and reduced waste gas disposal contribute to lower overall emissions.
Operational and Implementation
Are syngas engines suitable for continuous operation?
Yes, gas engines are designed for continuous operation in demanding industrial environments.
Can syngas power systems be integrated into existing plants?
Yes, systems can be integrated alongside existing gasification or process infrastructure with appropriate engineering design.
Looking to Make Better Use of Syngas From Your Process?
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