Experimental study of a clean burning vehicle fuel

Characteristics of direct injection combustion fuelled by natural gas–hydrogen mixtures using a constant volume vessel

“…The improvement of engine efficiency and reduction of emissions will be realized by adding a small amount of hydrogen into the natural gas under the lean mixture operation [9][10][11][12]. Lean-burn capability of the natural gas could be improved by hydrogen addition, leading to further improvement of engine thermal efficiency and reduction in emissions [13,14]. Moreover, hydrogen addition could increase the tolerance of large EGR while maintaining the low cycle-by-cycle variations, making the engine NO x reduction by 80% [15].…”

A Review of Hydrogen-Natural Gas Blend Fuels in Internal Combustion Engines

“…However, such conditions cause an increase in THC emissions, as shown in Figure 9. Hoekstra et al (1995) obtained very low NOx emissions operating with HCNG blends close the lean limit, significantly extended compared with natural gas. Besides, the excellent anti Fig.…”

Use of Hydrogen-Methane Blends in Internal Combustion Engines

“…They also found that as the hydrogen percentage increases, the lean limit of combustion is significantly extended. Hoekstra et al [52] observed a reduction in NOx for hydrogen percentages up to 30%, beyond this limit no improvement was observed. An important point was the higher flame speed and a consequent reduction of the spark advance angle to obtain the maximum brake torque, as already indicated by Nagalingam et al [46].…”