Understanding octane number evolution for enabling alternative low RON refinery streams and octane boosters as transportation fuels

摘要

Most of the time, spark ignition (SI) engine performance is limited by knock phenomena (especially for turbocharged engines), which are linked to fuel resistance to auto-ignition, quantified by its octane number (Research Octane Number - RON and Motor Octane Number - MON). If high octane numbers are crucial for efficient high load operating points, they are less necessary at low load. Thus, if the octane number of the fuel could be tuned as any other engine setting parameter, the engine efficiency and CO2 emissions could be improved, leading to an "Octane on Demand" concept, using for instance a dual fuel strategy. This requires understanding the behavior of dual fuel combustions with lower/higher octane fuels, and more particularly the evolution of RON when blending high RON fuels with low RON ones.