One of the most important potential applications for green liquefied fuel gas is clean cooking. LPG is already widely used for domestic cooking, and a sustainable fuel that can work in existing LPG appliances could offer a practical route to lower-carbon household energy without requiring major changes to stoves, cylinders or user behaviour.
This GreenQUEST demonstration tested whether gLFG produced in the project mini-plant could perform in a conventional LPG cookstove. The trial used a Cadac two-plate LPG stove and compared the project-produced gLFG with fossil LPG under controlled test conditions. The primary gLFG sample was approximately 0.9 kg of fuel prepared from mini-plant. Before testing, the fuels were analysed by gas chromatography to understand their chemical composition and support interpretation of the cooking results.
The test focused on practical performance. The team measured cooking time, fuel consumed, fuel flowrate, thermal efficiency, heat consumption rate and visible flame behaviour. The testing procedure was first refined using fossil LPG so that the limited gLFG sample could be used in a consistent and repeatable way.
The results were encouraging. The gLFG sample achieved a normalised cooking time of 18.6 minutes, compared with 18.2 minutes for fossil LPG. Although the gLFG required slightly more fuel for the same heating task – approximately 0.06 kg compared with 0.05 kg for fossil LPG – the overall cooking duty was closely comparable. Thermal efficiency was 73.8% for gLFG and 78.3% for fossil LPG, while heat consumption remained in a similar range.
These results show that gLFG can be combusted successfully in a conventional LPG cookstove and can provide useful cooking performance without changes to the appliance. For GreenQUEST, this is an important milestone because it validates gLFG in one of the most immediate and socially relevant LPG applications.
The demonstration also identified important next steps. The gLFG sample was still a crude product from the mini-plant and contained components outside the ideal propane-butane fuel range, including some heavier hydrocarbons. These are likely to have contributed to partial flame instability under a visual wind-exposure test and soot deposition after testing. This indicates that the main limitation was not stove compatibility, but fuel quality from the mini-plant. Improved downstream separation of the gLFG fraction will reduce heavier hydrocarbon content, improve flame stability and bring the product closer to commercial LPG specifications.
The impact of this outcome is that GreenQUEST has shown a credible pathway for using gLFG in existing cooking infrastructure. With further fuel-quality improvements, gLFG could become a technically compatible low-carbon alternative for LPG-based domestic cooking.