Economic feasibility of hydrogen enrichment for reducing NOx emissions from landfill gas power generation alternatives: A comparison of the levelized cost of electricity with present strategies

Performance and NOx emissions of a biogas-fueled turbocharged internal combustion engine

“…The NO x emissions decreased with increasing relative air/fuel ratio because the heat capacity of the mixture increased. Predicted NO x have similar trends from other experimental researches [7,11,18,20,28].…”

“…According to a recent study, the normalized cost to produce a unit of electricity increases by a factor of 2.2 by including H 2 , and also by a factor of 1.6 or 1.2 by using a steam reformer or an auto-thermal reformer, respectively [20]. Increasing the compression ratio of the engine is not straightforward because the engine itself must be modified; however, the use of a turbocharger can produce many of the same benefits, and is simple to implement since gas engines are typically based on diesel engines, which usually use a turbocharger for forced induction [21e23].…”

Two-Phase Anaerobic Digestion to Reduce the NOx Emission Potential of Biogas

“…At 15 H 2 :85 CH 4 by volume, reduced NOx emissions and engine efficiency are optimized (Choudhuri & Gollahalli, 2000;Collier et al, 1996;Shrestha & Karim, 1999;Sierens, 1998) Transporting hydrogen is also costly. Kornbluth et al (2012) found the overall costs of importing commercial hydrogen for enriching landfill gas (mostly CH 4 /CO 2 ) to reduce NOx emissions were 45 -100% higher than NOx control alternatives not requiring fuel purchase (e.g. lean burn, SCR, microturbine).…”

“…A potential NOx emissions control strategy that might be financially feasible is to enrich the biogas with hydrogen (Kornbluth et al, 2012). Studies have shown that hydrogen-methane mixtures at a ratio of approximately 15% H 2 to 85% CH 4 by volume (henceforth referred to as 15:85 H 2 :CH 4 ), burn with significantly lower NOx emissions when combusted at ultra lean air-to-fuel ratios (Choudhuri & Gollahalli, 2000;Collier, Hoekstra, Mulligan, Jones, & Hahn, 1996;Shrestha & Karim, 1999;Sierens, 1998).…”