Can hydrogen enriched biogas be used as domestic fuel? - Part II: Pollutants Emission from Combustion of Biogas/H2/air Fuel Mixture

Biogas is considered a sustainable source of energy which is largely untapped owing to its inherent weaknesses such as low thermal performance and potentially harmful emissions. Its thermal performance and emission characteristics can be enhanced through the technique of enriching with higher grade fuel. In this research study, biogas enriched with hydrogen was tested for its emission characteristics. A synthetic biogas identified as BG60 (60% CH4 and 40% CO2) enriched with 20% hydrogen (80%BG60-20%H2) was used for the test. Experiments were carried out for combustion of the enriched gas for a wide range of Reynolds numbers and equivalence ratios. The results indicate that the enriched fuel emits less CO and NOx than commonly used domestic fuel LPG. It also has a better thermal and emission performance than BG60. The low pollutant emissions compared with LPG, use of renewable feedstock for biogas production, and competitive cost may make the blended 80%BG60-20%H2 an attractive sustainable alternative domestic fuel choice for environmentally conscious urban dwellers of modern cities.