The use of hydrogenated fuels shows considerable promise for applications in gas turbines and internal combustion engines. The aims of this study are to determine the flammability limits of natural gas/ air and to investigate the effect on flammability limit of natural gas/ air enriched up to 60% hydrogen of fuel by volume at atmospheric pressure and ambient temperature. The experiments were performed in a 20 L closed explosion vessel. The mixtures were ignited by using spark permanent wire that placed at the centre of the vessel. The pressure-time variations during explosions of natural gas/air mixtures in explosion vessel were recorded. The explosion pressure data is used to determine the flammability limit which flame propagation is considered occurred if explosion pressure greater than 0.1 bar. In this study, the result shows the flammability limits is from 6 vol% to 15 vol% of natural gas and have revealed that the addition of hydrogen in natural gas extends the lower flammability limit initially 6 vol% to 2 vol% of methane.

Combustion of fossil fuels has caused serious problems to the environment and the geopolitical climate of the world. The main negative effects on the environment by fossil fuel combustion are emissions of NOx, CO, CO2, and unburned hydrocarbons. The theory behind this concept is that the addition of hydrogen can extend the lean explosion limit, improve the lean burn ability, and decrease burn duration in order to decrease the formation of NOx, CO and unburned hydrocarbons. The objective of this research is to determine the effect of hydrogen enrichment in natural gas (NG) on explosion limit of NG. The target in first experiment is to extend the range of explosion limit in order to improve the thermal efficiency and reduce the emission into environment. Data for experiment was to be set up by fixed 1% of hydrogen addition in natural gas which is natural gas is incrementally increase by 1%, 2% until no explosion had been occurred. Addition of hydrogen is followed by 1%, 4%, 6%, and 8% by pressure but not exceeds 10%. The experiments are carried out by using the gas fire explosion unit. Data from the experiments been analyzed for where is to compare the data with and without hydrogen addition. Results shown that the range of lower explosion limit (LEL) on natural gas will be extending from 6% volume (LEL) and 12% volume (UEL) to 1% volume (LEL) and 18% volume (UEL) when introduced hydrogen for 1% to 8% volume by pressure. The highest maximum pressure recorded at 5.9 bars at 8% volume of hydrogen enrichment. From the experiments, range of explosion limit on natural gas would be extending by addition of hydrogen.

This literature survey digest of hydrogen-air combustion fundamentals presents data on flame temperature, burning velocity, quenching distance, flammability limits, ignition energy, flame stability, detonation, spontaneous ignition, and explosion limits. The data are assessed, recommended values are given, and relations among various combustion properties are discussed. New material presented includes: theoretical treatment of variation in spontaneous ignition lag with temperature, pressure, and composition, based on reaction kinetics of hydrogen-air composition range for 0.01 to 100 atmospheres and initial temperatures of 0 degrees to 1400 degrees k.

The use of hydrogenated fuels shows considerable promise for applications in gas turbines and internal combustion engines. The aims of this study are to determine the explosive limits of liquefied petroleum gas/air mixture and to investigate the effect on explosive limits liquefied petroleum gas/air mixture enriched up to 8 vol % hydrogen by total volume at atmospheric pressure and ambient temperature. The experiments were performed in 20 Liter closed explosion vessel. The mixtures were ignited by using spark permanent wire that placed at the centre of the vessel. The pressure-time variations during explosion of liquefied petroleum gas/air mixture in explosion vessel were recorded. The explosion pressure data is used to determine the explosive limits which flame propagation is considered to occur if explosion pressure greater than 0.1 bar. In this study the result shows the explosive limits is from 2 to 8 vol % of liquefied petroleum gas/air mixture and have revealed that the addition of hydrogen in liquefied petroleum gas/air mixture decreases the lower explosive limits from 2 to 1 vol % and for the upper explosive limits, the limits is also decrease from 8 to 7 vol %.