Performance of biogas blended with hydrogen in a commercial self-aspirating burner

Abstract

A natural gas and carbon dioxide fuel mixture was enriched by hydrogen to experimentally measure the performance of a hydrogen and surrogate biogas fuel. The performance of various biogas qualities and hydrogen blend ratios was investigated for use in a commercial self-aspirating burner by quantifying the impact on primary air entrainment, blow-off and flashback limits, NOx emissions, radiant heat transfer and flame appearance. The results showed operating limits of a biogas or hydrogen flame alone could be extended by blending one with the other and by increasing fuel injector size (lowering primary air entrainment), with the latter being more effective. The collateral impact of carbon dioxide and hydrogen addition on radiant heat transfer could be mitigated by increasing injector size, with the carbon dioxide content in biogas maintaining NOx levels at or below the level of natural gas. Overall, there appears to be merit for hydrogen and biogas to operate as a mutually beneficial fuel in a commercial self-aspirating burner design.