Evaluation of the Chemical Quality of Liquid Petroleum Gas and Adulteration in Supply Chains Across North Central Nigeria

Liquefied petroleum gas, comprising mainly propane and butane, is an increasingly important domestic and commercial cooking fuel across North Central Nigeria, but there are growing concerns about adulteration with heavier hydrocarbon fractions and incorrect compositional blending that affect combustion safety and appliance compatibility. This study evaluated the chemical quality and compositional purity of liquefied petroleum gas samples collected from distribution points, cylinder filling plants, and retail outlets across Abuja, Nasarawa, and Niger State. Thirty samples were collected in stainless steel canisters and analysed by gas chromatography using a thermal conductivity detector. Density, vapour pressure, and copper corrosion tests were also performed. Compositional analysis revealed that 33 percent of samples did not conform to the DPR standard for commercial LP gas, with excess pentane and hexane fractions indicating contamination with natural gasoline or condensate. Vapour pressure values ranged from 6.1 to 18.4 bar, with some samples exhibiting lower-than-specified pressure consistent with heavy fraction dilution. Copper strip corrosion tests were passed by 83 percent of samples. Sulphur content was within specification in all samples. These findings indicate a significant adulteration problem in the LP gas supply chain in North Central Nigeria, raising appliance overpressurisation risks and incomplete combustion concerns. The study recommends mandatory portable GC-based quality testing at cylinder filling points and enhanced DPR supply chain auditing across the distribution network.

Keywords: liquefied petroleum gas, adulteration, gas chromatography, fuel quality, North Central Nigeria