October 2020

F or as long as I can remember, the questions arising from presentations to our sector usually involve at least one about hydrogen. This can be seen as an abundant, readily available resource and a solution to long-term electric power generation akin to nuclear fusion, in that in both cases the by-product is harmless. Pure hydrogen is an important component of many industrial chemical processes, so generation of more hydrogen to feed transportation will add pressure to existing industrial capacity. Hydrogen exists either in association with itself (H3 – which is unstable) or with other atoms (for example water, H2O – which is stable). It also exists inside many, many organic compounds, but effectively is not available in nature as a pure gas. Pure hydrogen can be manufactured from coal, oxidation of methane or steam reforming of methane. Methane is a principle component of natural gas, so there is a plentiful supply of raw material. Most of the pure hydrogen available for use today is made by one of these industrial processes, which all require energy to effectively extract the hydrogen and then more energy to compress it to the point the gas liquifies. Hydrogen can also be extracted by passing electricity through water, and there have been many aftermarket kits that do exactly this to generate a form of hydrogen peroxide which is then ducted into an internal combustion engine intake system to offset the hydrocarbon fuel burn rate. However, if we need to generate pure hydrogen on a scale to develop transport, this process needs to be upscaled. The conclusion: Pure hydrogen prefers to be attached to other atoms to achieve stability, and if we need to extract it requires is an energy investment. Further, the most common source of pure hydrogen is from natural gas, where the by- products are carbon dioxide and carbon monoxide. Hardly right-on. The application Let’s skip eco-obstacles. What can we do with it? There are essentially two routes to use hydrogen. Some manufacturers openly experimented with hydrogen as a fuel for internal combustion engines. Mazda built several Wankel engines fuelled by hydrogen. In theory, apart from trace hydrocarbon pollution due to lubricants, the tail pipe emissions would be zero in terms of traditionally 24 AFTERMARKET OCTOBER 2020 TECHNICAL www.aftermarketonline.net HYDROGEN – THE NEXT REVOLUTION? Automotive engineer and all-round technical seer Andrew Marsh checks the Periodic Table to see if hydrogen might be the next great leap forward in vehicle technology BY Andrew Marsh, Engineering Director, Ezi-Methods