Octane levels play an important part in determining the performance, efficiency and suitability of fuel. Testing for the Research Octane Number (RON) is a useful way to profile fuel and determine how much compression gasoline can withstand before combusting in the engine, indeed RON indicates the combustibility of engine fuel at low speeds and temperatures. It’s designed to reflect the behavior of fuel under idling conditions and during acceleration. The higher the RON rating, the more compression it can withstand in a spark-ignition engine before igniting.

Despite the existence of established ASTM standards for RON¹ measurement, there remain noteworthy obstacles that need to be addressed. Conducting ignition quality tests, through the recommended methods using Cooperative Fuel Research (CFR) engine or Constant Volume Combustion Chamber (CVCC) as it is stipulated by ASTM standards, proves to be both costly and time consuming. The range of RON values typically varies between 0, for n¬ heptane, and 100 for iso-octane. However, in practical terms, the RON values of commercial gasoline fuels usually fall within the range of 85 to 100. However, advancements in fuel technology and refining processes have led to the development of specialized fuels with RON values exceeding 100. Several aromatic hydrocarbons, such as toluene (RON = 120¹) or o-xylene (RON = 105²), are used since long as additives to increase fuel octane rating. These compounds have RON values above 100 and contribute raising significantly the overall fuel RON. Oxygenates such as ethanol (RON = 108.6³) or methanol (RON =108.7³) are currently also added to fuel mixtures. These compounds have high octane ratings and also enhance the anti-knock properties of the fuel.

With the increasing demand in alternative fuels and the use of biomass as the feedstock for the production of fuel commodities, a wider range of oxygenated hydrocarbons as fuel additives needs to be considered. This can be especially the case of aromatic oxygenates, such as those shown in Table 1, which can be produced from lignin⁴ by catalytical processes, as proposed in the EHLCATHOL European project (http://ehlcathol.eu/).

Unfortunately, the literature is poor in data for RON values, which are only available for a limited set of compounds and chemical families and even more for compounds such as aromatics oxygenates such as o-guaiacol or cresol isomers. Therefore, it will become necessary to develop methodologies in order to estimate RON of diverse compounds.

 

Hit the button in order to get an access to the web frontend of the multimodal neural network-based tool for computation of RON of any H, C, O, N hydrocarbons.