The Future Fuel Europe Already Has in the Tank
by Emmanuel Desplechin (Politico/ePURE) Renewable ethanol does more than just decarbonize transport. It also boosts engine efficiency and helps improve air quality. — The European Commission has just told the Belgian government that it needs to do a better job of tackling “serious air pollution problems” from vehicle emissions. That is, of course, an admirable goal but the warning raises the question of why the Commission is at the same time proposing to phase out an alternative transport fuel that already helps reduce harmful emissions and urban air pollutants from cars: renewable ethanol.
The debate over how best to boost renewables in Europe’s energy mix has mostly been focused on which fuels can reduce greenhouse gases and which are the most sustainably produced. On that score, European renewable ethanol is already among the leaders of the pack, reducing greenhouse-gas emissions by an average of 64 percent over fossil petrol in 2015 – and that performance is improving each year.
But ethanol also delivers significant benefits to engine performance and efficiency, with lower emissions of harmful pollutants compared to fossil petrol. At a time when Europeans are increasingly concerned about urban air quality and emission of pollutants from vehicles – particularly passenger cars – the EU should be boosting the use of clean-burning biofuels like renewable ethanol.
Instead it is considering doing the opposite.
Ethanol use in engines produces lower emissions of carbon monoxide (CO), which result from the incomplete combustion of fossil fuel. By using ethanol, with its high oxygen content, these harmful CO emissions can be reduced. The more ethanol used in the fuel tank, the lower its CO emissions.
Higher ethanol blends also produce lower levels of polluting nitrogen oxide (NOx) emissions, which have a serious impact on the environment and human health. NOx is produced when fuels burn at high temperature. Higher blends of ethanol can reduce NOx emissions because of ethanol’s cooling effect on engine temperature.
Incomplete engine combustion also creates polluting emissions of unburned hydrocarbons (HC). But by increasing the ethanol content of the fuel tank these emissions can be reduced, thanks to a better use of energy and a reduced share of HC.