Hydrogen internal combustion engines (H2ICE) have shown enormous potential for zero-carbon emissions, aligning with the European zero-carbon targets in 2050. Adopting hydrogen as a zero-carbon fuel offers a time- and cost-effective approach to directly replacing carbon-based and fossil fuel-powered ICEs.The study aims to provide comprehensive data on the H2ICE engine during steady-state operations of a single-cylinder spark ignition engine with a direct hydrogen injection system. It focuses on emissions, including carbon monoxide (CO) and unburnt hydrocarbons (HC), utilising ultra-fast analysers positioned close to the exhaust valves to minimise signal delay. Particulate matter (PM) emissions are also measured to evaluate the potential for zero-carbon emissions from the H2ICE. Additionally, NO and NO2 emissions are analysed against air-fuel ratios (AFR) to estimate combustion temperature and NOx mechanisms. Water vapour and oxygen emissions are captured to assess their quantities under different loads and to verify the actual Lambda compared to the wideband O2 sensor.The study's main findings show that by looking at the averaged data, the averaged CO2 and HC emissions were less than 0.02% over mid-load of 10 bar IMEP at 2000 rpm and a lambda value of 2.75. However, examining cycle peak values near the exhaust valve opening reveals small spikes under 100 ppm, which have been correlated with PM emissions data to confirm carbon emissions resulting from lubricant induction. These emissions exhibit distinct characteristics, particularly during periods of higher coefficient of variation (COV), and are captured during abnormal combustion events. This suggests increased piston acceleration leads to greater lubricant entry into the combustion chamber. Additionally, an impressive water vapour peak value of 42.7% of the exhaust volume at lambda 1 indicates great potential for adopting EGR and water injection.
Mohamed et al. (Sun,) studied this question.